WO2024189869A1 - Position adjustment device, reception device, transmission device, communication device, and communication system - Google Patents

Abstract

A position adjustment device comprising: a rotation mechanism in which an annular holding member for rotation is installed in order to adjust the position of a communication instrument in correspondence to every direction along the same plane; a holding mechanism that is disposed on each of a plurality of communication instruments and has a solenoid in which a movable core, which includes a first fixed end facing the holding member for rotation and a second fixed end facing a holding member for fixation, is inserted into a coil, the movable core moving toward the holding member for rotation, with the first fixed end being held by the holding member for fixation, in response to energization of the coil, and the movable core moving toward the holding member for fixation and being separated from the holding member for rotation in response to deactivation of the energization of the coil; and a control unit that executes control to energize the coil of the solenoid in the holding mechanism, in which a communication instrument used for communication with a communication target is disposed, to rotate the rotation mechanism, and to direct the communication direction of the communication instrument toward the communication target.

Description

Position adjustment device, receiving device, transmitting device, communication device, and communication system

This disclosure relates to a position adjustment device used to adjust the position of a communication device that transmits and receives spatial optical signals.

In free space optical communication, optical signals (hereafter referred to as spatial optical signals) that propagate through space are sent and received without using a medium such as optical fiber. Compared to the radio waves used in wireless communication, the spatial optical signals used in optical space communication are highly directional. In addition, spatial optical signals do not interfere with radio waves. In the field of spatial optical communication, an optical communication network can be constructed using opposing optical communication devices.

Patent Document 1 discloses multiple optical transmitters and receivers arranged on approximately the same plane as repeaters for forming an optical communications network. The device in Patent Document 1 includes a detector, a focusing optical system, and a light-emitting element. The detector receives signal light transmitted from other optical transmitters and receivers. The focusing optical system is attached to a rotating body having an axis of rotation perpendicular to the plane on which the optical transmitters and receivers are arranged. The focusing optical system focuses the signal light on the detector. The light-emitting element is attached to a stationary body separate from the rotating body. The light-emitting element radiates signal light to the surroundings to be transmitted to other optical transmitters and receivers.

JP 2017-076837 A

According to the technique of Patent Document 1, by pointing a focusing optical system at other optical transceivers that form an optical communication network, it is possible to receive signal light transmitted from each optical transceiver. However, with the technique of Patent Document 1, it is not possible to simultaneously receive signal light transmitted from multiple optical transceivers that form an optical communication network. Furthermore, with the technique of Patent Document 1, it is only possible to transmit signal light to optical transceivers whose positions have been specified in advance.

The purpose of this disclosure is to provide a position adjustment device etc. that can adjust the position of a communication device in correspondence with any direction along the same plane.

A position adjustment device according to one embodiment of the present disclosure includes a rotation mechanism having an annular rotating holding member; a holding mechanism that is arranged on each of a plurality of communication devices and has a solenoid in which a movable core including a first fixed end facing the rotating holding member and a second fixed end facing the fixed holding member is inserted into a coil, in which the movable core moves towards the rotating holding member in response to energization of the coil so that the first fixed end is held by the rotating holding member, and in response to de-energization of the coil, the movable core moves towards the fixed holding member and separates from the rotating holding member; and a control unit that energizes the coil of the solenoid in the holding mechanism in which a communication device used for communication with a communication target is arranged, and rotates the rotation mechanism to control the communication direction of the communication device to face the communication target.

This disclosure makes it possible to provide a position adjustment device that can adjust the position of a communication device in correspondence with any direction along the same plane.

FIG. 2 is a conceptual diagram showing a configuration example of a receiving device according to the first embodiment. 4 is a conceptual diagram showing a configuration example of a holding mechanism included in the receiving device according to the first embodiment. FIG. 5 is a conceptual diagram for explaining a state in which the solenoid of the holding mechanism included in the receiving device according to the first embodiment is de-energized. FIG. 5 is a conceptual diagram for explaining a state in which a solenoid of a holding mechanism included in the receiving device according to the first embodiment is energized. FIG. 4 is a conceptual diagram showing an example of the arrangement of holding rods included in a plurality of holding mechanisms included in the receiving device according to the first embodiment. FIG. 10 is a conceptual diagram for explaining a first example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 10 is a conceptual diagram for explaining a first example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 11 is a conceptual diagram for explaining a second example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 11 is a conceptual diagram for explaining a second example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a third example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a third example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a fourth example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a fourth example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a fifth example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a fifth example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a sixth example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a sixth example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a sixth example of a rotation holding member that holds a first fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 10 is a conceptual diagram for explaining a first example of a fixing holding member that holds a second fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 10 is a conceptual diagram for explaining a first example of a fixing holding member that holds a second fixed end of a holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a second example of a fixing holding member that holds a second fixed end of the holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a second example of a fixing holding member that holds a second fixed end of the holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a third example of a fixing holding member that holds a second fixed end of the holding mechanism provided in the receiving device according to the first embodiment. FIG. 13 is a conceptual diagram for explaining a third example of a fixing holding member that holds a second fixed end of the holding mechanism provided in the receiving device according to the first embodiment. FIG. 4 is a flowchart for explaining an example of operation of the receiving device according to the first embodiment. FIG. 11 is a conceptual diagram showing an example of the configuration of a receiving device according to a second embodiment. FIG. 13 is a conceptual diagram illustrating an example of the configuration of a receiving device according to a first modified example of the second embodiment. FIG. 13 is a conceptual diagram illustrating an example of the configuration of a receiving device according to Modification 2 of the second embodiment. FIG. 13 is a conceptual diagram showing an example of an image captured by a fisheye camera of a receiving device of Modification 2 according to the second embodiment. FIG. 13 is a conceptual diagram illustrating an example of the configuration of a transmission device according to a third embodiment. FIG. 13 is a conceptual diagram illustrating a configuration example of a transmission device according to a third modification of the third embodiment. FIG. 23 is a conceptual diagram showing an example of direction detection using a direction detection optical receiver of a transmission device according to a third modified example of the third embodiment. FIG. 13 is a conceptual diagram illustrating a configuration example of a transmission device according to a fourth modified example of the third embodiment. 13 is a conceptual diagram for explaining an image captured by a fisheye camera provided in a transmitting device according to a fourth modified example of the third embodiment. FIG. 13 is a flowchart for explaining an example of operation of a transmitting device according to the third embodiment. FIG. 13 is a conceptual diagram illustrating an example of the configuration of a communication device according to a fourth embodiment. FIG. 13 is a conceptual diagram for explaining a track structure provided in a communication device according to a fourth embodiment. 13A and 13B are conceptual diagrams for explaining the movement of a drive part of a rotation mechanism included in a communication device according to a fourth embodiment. FIG. 13 is a conceptual diagram showing an example of the positional relationship between a receiver and a transmitter included in a communication device according to a fourth embodiment. 13 is a conceptual diagram showing a configuration example of a first relay mirror included in a communication device according to a fourth embodiment. FIG. 13 is a conceptual diagram showing a configuration example of a second relay mirror included in a communication device according to a fourth embodiment. FIG. FIG. 13 is a conceptual diagram illustrating an example of the configuration of a communication device according to a fifth modified example of the fourth embodiment. FIG. 13 is a conceptual diagram for explaining an application example of a communication device according to a fourth embodiment. FIG. 13 is a conceptual diagram showing an example of the configuration of a position adjustment device according to a fifth embodiment. FIG. 2 is a block diagram showing an example of a hardware configuration for executing control and processing according to each embodiment.

Below, the embodiments for implementing the present invention are described with reference to the drawings. However, the embodiments described below have limitations that are technically preferable for implementing the present invention, but do not limit the scope of the invention to the following. In addition, in all the drawings used to explain the embodiments below, similar parts are given the same reference numerals unless there is a specific reason. Furthermore, in the embodiments below, repeated explanations of similar configurations and operations may be omitted.

In all the figures used to explain the following embodiments, the direction of the arrows in the figures is an example and does not limit the direction of light or signals. Furthermore, the lines showing the trajectory of light in the figures are conceptual and do not accurately represent the actual direction or state of light. For example, in the figures, changes in the direction or state of light due to refraction, reflection, diffusion, etc. at the interface between air and material may be omitted, or a light beam may be represented by a single line. Furthermore, cross sections may not be hatched in order to illustrate an example of the path of light or for other reasons such as a crowded configuration.

First Embodiment
First, the receiving device according to the first embodiment will be described with reference to the drawings. The receiving device according to this embodiment is used for optical space communication in which an optical signal propagating through space (hereinafter also referred to as a spatial optical signal) is transmitted and received. The receiving device according to this embodiment may be used for purposes other than optical space communication as long as it receives light propagating through space. Note that the drawings used in the description of this embodiment are conceptual and do not accurately depict the actual structure.

(composition)
FIG. 1 is a conceptual diagram showing an example of the configuration of a receiving device 1 according to this embodiment. The receiving device 1 includes a ball lens 10, a receiver 12, a holding mechanism 17, a rotation mechanism 18, and a control unit 19. The holding mechanism 17, the rotation mechanism 18, and the control unit 19 constitute a position adjustment device. The receiver 12 is a form of a communication device. The receiver 12 and the holding mechanism 17 are paired. The receiving device 1 includes a plurality of pairs of the receiver 12 and the holding mechanism 17. FIG. 1 is a cross-sectional view of the receiving device 1 as seen from a side perspective. The receiving device 1 is stored inside a housing (not shown) in which an opening or window for receiving a spatial optical signal is formed. FIG. 1 is conceptual and does not accurately represent the shape of each component or the positional relationship between the components.

The ball lens 10 is supported by a ball lens receiver 111 that has the shape of an upside-down spherical crown. The ball lens receiver 111 is disposed on the top of a support pillar 112 that is erected in the center of a disk-shaped base 110. The support pillar 112 is surrounded by a cylindrical pillar 113. A first bearing 115 having an annular shape is disposed on the side of the cylindrical pillar 113. A ring-shaped annular pillar 117 is disposed on the periphery of the upper surface of the base 110. A second bearing 118 having an annular shape is disposed on the inner edge of the upper part of the annular pillar 117. The bearing portions of the first bearing 115 and the second bearing 118 face each other at the same height. A ring-shaped fixing retaining member 176 is disposed on the upper surface of the base 110. The fixing retaining member 176 is formed along the lower side of the second fixed end 172 of the retaining mechanism 17. A ring-shaped annular track 184 is disposed on the upper surface of the annular pillar 117. In addition, a rotation mechanism 18 is disposed on the upper surface of the annular column 117.

A circuit area 119 is formed inside the base 110. A processing board (not shown) on which a control unit 19 is mounted is housed in the circuit area 119. The control unit 19 includes a drive function for driving the holding mechanism 17 and the rotation mechanism 18, and a receiving function for processing the spatial light signal received by the receiver 12. Wiring between the components of the receiving device 1 and the control unit 19 is omitted. The control unit 19 may be located externally instead of in the circuit area 119. For example, the control unit 19 may be implemented in a server or cloud connected via a communication network such as the Internet or an intranet.

The ball lens 10 is a spherical lens. The ball lens 10 is an optical element that focuses a spatial optical signal arriving from the outside. The ball lens 10 is spherical when viewed from any angle. The ball lens 10 focuses the incident spatial optical signal. The light (also called an optical signal) originating from the spatial optical signal focused by the ball lens 10 is focused toward the focusing area of the ball lens 10. Since the ball lens 10 is spherical, it focuses a spatial optical signal arriving from any direction. In other words, the ball lens 10 exhibits the same focusing performance for spatial optical signals arriving from any direction. The light that enters the ball lens 10 is refracted when it enters the inside of the ball lens 10. Furthermore, the light traveling inside the ball lens 10 is refracted again when it is emitted to the outside of the ball lens 10. Most of the light emitted from the ball lens 10 is focused in the focusing area.

For example, ball lens 10 can be made of materials such as glass, crystal, and resin. When receiving a spatial light signal in the visible range, materials such as glass, crystal, and resin that transmit/refract light in the visible range can be used for ball lens 10. For example, optical glass such as crown glass and flint glass can be used for ball lens 10. For example, crown glass such as BK (Boron Kron) can be used for ball lens 10. For example, flint glass such as LaSF (Lanthanum Schwerflint) can be used for ball lens 10. For example, quartz glass can be used for ball lens 10. For example, crystal such as sapphire can be used for ball lens 10. For example, transparent resin such as acrylic can be used for ball lens 10.

When the spatial light signal is light in the near-infrared region (hereinafter also referred to as near-infrared), a material that transmits near-infrared light is used for the ball lens 10. For example, when receiving a spatial light signal in the near-infrared region of about 1.5 micrometers (μm), materials such as silicon can be used for the ball lens 10 in addition to glass, crystal, resin, etc. When the spatial light signal is light in the infrared region (hereinafter also referred to as infrared), a material that transmits infrared light is used for the ball lens 10. For example, when the spatial light signal is infrared, materials such as silicon, germanium, and chalcogenide-based materials can be used for the ball lens 10. There are no limitations on the material of the ball lens 10 as long as it can transmit/refract light in the wavelength region of the spatial light signal. The material of the ball lens 10 may be selected appropriately according to the desired refractive index.

Receiver 12 has photodetector 121, support 122, retaining rod 123, first end 125, and second end 126. Photodetector 121 is positioned in the light collecting area of ball lens 10 by support 122. The light receiving surface of photodetector 121 faces ball lens 10. Support 122 is a rod-shaped column with two bent points when viewed from the side. Photodetector 121 is positioned above support 122, facing ball lens 10. The lower end of support 122 is fixed to the upper part of retaining rod 123. Retaining rod 123 is a rod-shaped member extending radially from the center of the base. Retaining rod 123 has first end 125 and second end 126 formed in a spherical shape. First end 125 is inserted into the bearing portion of first bearing 115. The second end 126 is inserted into the bearing portion of the second bearing 118. The first end 125 slides in the bearing portion of the first bearing 115 in response to the movement of the retaining rod 123. Similarly, the second end 126 slides in the bearing portion of the second bearing 118 in response to the movement of the retaining rod 123. That is, in response to the movement of the retaining rod 123, the support 122 supporting the optical receiver 121 moves around the ball lens 10. As a result, the light receiving direction of the light receiving surface of the optical receiver 121 is changed.

The optical receiver 121 is disposed in a position facing the ball lens 10 above the support 122. At least one light receiving element is disposed on the light receiving surface of the optical receiver 121. The light receiving element has a light receiving portion that receives an optical signal. The light receiving portion of the light receiving element is directed toward the ball lens 10. An optical signal focused by the ball lens 10 is incident on the light receiving portion of the light receiving element. The light receiving element receives the optical signal that is incident on the light receiving portion. The light receiving element converts the received optical signal into an electrical signal. The converted electrical signal is output to the control unit 19.

The light receiving element receives light in the wavelength region of the spatial optical signal to be received. For example, the light receiving element is sensitive to light in the visible region. For example, the light receiving element is sensitive to light in the infrared region. The light receiving element is sensitive to light in the 1.5 μm (micrometer) band. The wavelength band of light to which the light receiving element is sensitive is not limited to the 1.5 μm band. The wavelength band of light received by the light receiving element can be set arbitrarily to match the wavelength of the spatial optical signal transmitted from the transmitting device (not shown). The wavelength band of light received by the light receiving element may be set to, for example, the 0.8 μm band, the 1.55 μm band, or the 2.2 μm band. The wavelength band of light received by the light receiving element may be, for example, the 0.8 to 1 μm band. A shorter wavelength band is advantageous for optical space communication during rainfall because it is less absorbed by moisture in the atmosphere. Also, if the light receiving element becomes saturated with intense sunlight, it cannot read the optical signal derived from the spatial optical signal. Therefore, a color filter that selectively passes light in the wavelength band of the spatial light signal may be installed in front of the light receiving element.

For example, the light receiving element can be realized by elements such as photodiodes and phototransistors. For example, the light receiving element can be realized by an avalanche photodiode. A light receiving element realized by an avalanche photodiode can support high-speed communication. Note that the light receiving element may be realized by elements other than photodiodes, phototransistors, and avalanche photodiodes as long as it can convert an optical signal into an electrical signal. In order to improve the communication speed, it is preferable that the light receiving portion of the light receiving element is as small as possible. For example, the light receiving portion of the light receiving element has a square light receiving surface with one side of about 5 mm (millimeters). For example, the light receiving portion of the light receiving element has a circular light receiving surface with a diameter of about 0.1 to 0.3 mm. The size and shape of the light receiving portion of the light receiving element may be selected according to the wavelength band of the spatial optical signal, the communication speed, etc.

For example, the light receiver 121 may be configured to combine a first light receiving element that receives notification light and a second light receiving element that receives communication light. Notification light is light used by the communication target to notify its location. For example, notification light is derived from light emitted from an LED (Light Emitting Diode) light source installed in the communication target. Communication light is a spatial light signal transmitted from the communication target. For example, communication light is derived from light emitted from a laser light source installed in the communication target.

The first light receiving element (not shown) is used to receive a spatial light signal (notification light) for notification. Compared to the light receiving surface of the second light receiving element, the light receiving surface of the first light receiving element has a larger area. The first light receiving element is sensitive to light in the wavelength band of the notification light. For example, the first light receiving element is realized by a silicon-based photodiode. The light receiving surface of the first light receiving element converts the notification light received by the first light receiving element into an electrical signal. The converted electrical signal is output to the control unit 19.

The second light receiving element (not shown) is used to receive a spatial optical signal (communication light) for communication. Compared to the light receiving surface of the first light receiving element, the light receiving surface of the second light receiving element has a smaller area. The second light receiving element is sensitive to light in the wavelength band of the communication light. For example, the second light receiving element is realized by a photodiode that is sensitive to infrared light. For example, the second light receiving element is realized by an indium gallium arsenide (InGaAs) photodiode. The communication light received by the second light receiving element is converted into an electrical signal. The converted electrical signal is output to the control unit 19.

The holding mechanism 17 has a solenoid 170, a first fixed end 171, a second fixed end 172, a movable core 173, and a spring 174. FIG. 2 is a conceptual diagram showing an example of the configuration of the holding mechanism 17. FIG. 2 is an oblique view of the holding mechanism 17 seen from an obliquely upward perspective. The solenoid 170 is arranged on the holding rod 123 so as to penetrate vertically. A coil (not shown) is arranged inside the solenoid 170. A movable core 173 is inserted inside the coil. The movable core 173 (also called a plunger) is a metal that is magnetized in response to the passage of electricity through the coil. For example, the movable core 173 is ferritic or martensitic stainless steel. The first fixed end 171 is installed at the upper end of the movable core 173. For example, the first fixed end 171 has a shape in which multiple conical protrusions protrude upward. A rotation holding member 175 is arranged above the first fixed end 171. In this embodiment, when the coil is energized, the movable core 173 moves upward. When the coil is energized, the upper end portion of the first fixed end 171 is temporarily held by the rotation holding member 175. The second fixed end 172 is installed at the lower end of the movable core 173. For example, the second fixed end 172 has a shape in which multiple cone-shaped protrusions protrude downward. A fixing holding member 176 is disposed below the second fixed end 172. When the coil is not energized, the lower end portion of the second fixed end 172 is held by the fixing holding member 176. A spring 174 is disposed around the movable core 173 in a portion exposed to the outside from below the solenoid 170. The spring 174 is a spiral-shaped coil spring.

FIG. 3 is a conceptual diagram for explaining the state of the holding mechanism 17 when the coil of the solenoid 170 is not energized. When the coil of the solenoid 170 is not energized, the movable core 173 falls downward due to the elastic force of the spring 174 and gravity. In this state, the second fixed end 172 is held by the fixing holding member 176. With the second fixed end 172 held by the fixing holding member 176, the holding rod 123 on which the holding mechanism 17 is installed does not move.

FIG. 4 is a conceptual diagram for explaining the state of the holding mechanism 17 when the coil of the solenoid 170 is energized. When the coil of the solenoid 170 is energized, the movable core 173 moves upward. When the movable core 173 moves upward, the first fixed end 171 is temporarily held by the rotation holding member 175.

FIG. 5 is a conceptual diagram of the receiving device 1 viewed from above. FIG. 5 illustrates a state in which the ball lens 10, the ball lens holder 111, and the support column 112 are removed. FIG. 5 shows an example in which six holding rods 123 are arranged. The number of holding rods 123 is not limited to six. The holding rods 123 are arranged radially from the support column 112. FIG. 5 illustrates the tire 183 and the rotating table 185 included in the rotating mechanism 18. The side of the tire 183 contacts the side of the rotating table 185. The rotating table 185 rotates in response to the rotation of the tire 183. For example, each of the multiple holding rods 123 in the initial state is set to a preset initial position. The position of each holding rod 123 is adjusted by transmitting and receiving spatial light signals between the devices in accordance with the positional relationship (positional information) between the receiving device 1 and the communication target. It is preferable that the position of each holding rod 123 be accurately adjusted according to the number of rotations of the tire 183 and the rotating table 185. For example, a detector (not shown) for detecting the position of each holding rod 123 may be provided.

When the rotating table 185 is rotated around the support column 112 while the first fixed end 171 is held by the rotating holding member 175, the position of the holding mechanism 17 changes. In response to the change in the position of the holding mechanism 17, the holding rod 123 on which the solenoid 170 is disposed moves. As a result, the direction of the light receiving surface of the light receiver 121 disposed on the support column 122 held by the holding rod 123 changes.

When the coil of the solenoid 170 is de-energized, the movable core 173 falls downward in response to the elastic force of the spring 174, and the second fixed end 172 is held by the fixing holding member 176 (Figure 3). With the second fixed end 172 held by the fixing holding member 176, the holding rod 123 on which the holding mechanism 17 is installed does not move.

The rotation mechanism 18 has a motor 181, a rotating shaft 182, a tire 183, an annular track 184, and a rotating table 185. The rotating shaft 182 is the motor shaft of the motor 181. A tire 183 is attached to the rotating shaft 182. The material of the tire 183 is an elastic body such as rubber. The side of the tire 183 is arranged so as to be in contact with the side of the rotating table 185. The annular track 184 is an annular track centered on the support pillar 112. An annular groove is formed on the upper surface of the annular track 184 centered on the support pillar 112. The rotating table 185 is a cylindrical table that opens downward. An opening is formed on the upper surface of the rotating table 185 so as not to interfere with the support pillar 122 of the receiver 12. The lower end of the rotating table 185 forms a ring. The annular lower end of the rotating table 185 is fitted into the groove on the upper surface of the annular track 184. The rotating table 185 is rotatably arranged along a groove on the upper surface of the circular track 184. A tire 183 attached to the rotating shaft 182 rotates in accordance with the rotation of the rotating shaft 182 in response to the drive of the motor 181 by the drive function included in the control unit 19. The rotating table 185 rotates in accordance with the rotation of the tire 183.

A rotating holding member 175 is installed on the underside of the rotating table 185 in accordance with the position of the first fixed end 171 of the holding mechanism 17. As shown in FIG. 5, the rotating holding member 175 is formed in a circular ring shape centered on the support post 112. When the rotating table 185 rotates with the first fixed end 171 of any holding mechanism 17 held by the rotating holding member 175, the position of the receiver 12 paired with that holding mechanism 17 is changed.

The control unit 19 (control means) includes a driving function for driving the holding mechanism 17 and the rotation mechanism 18. The control unit 19 also includes a receiving function for processing the spatial light signal received by the receiver 12. For example, the control unit 19 is realized by a microcomputer having a processor and a memory.

In the stage of establishing communication with a communication target, the control unit 19 detects the communication target according to light received by any of the optical receivers 121 included in the multiple receivers 12. The control unit 19 identifies the direction of the detected communication target according to the state of light reception by the optical receiver 121. The control unit 19 selects the receiver 12 to be used for communication with the communication target in the identified direction. The control unit 19 energizes the coil of the solenoid 170 of the holding mechanism 17 paired with the selected receiver 12. When the coil is energized, the movable core 173 inserted in the coil moves upward. In this state, the first fixed end 171 of the holding mechanism 17 is held by the rotation holding member 175.

The control unit 19 drives the rotation mechanism 18 to orient the light receiving surface of the optical receiver 121 of the selected receiver 12 toward the communication target. The control unit 19 adjusts the position of the optical receiver 121 according to changes from the initial position of the optical receiver 121. When the light receiving surface of the optical receiver 121 of the selected receiver 12 is orientated toward the communication target, the control unit 19 releases the power to the solenoid 170 of the holding mechanism 17 paired with the selected receiver 12. When the power is released, the second fixed end 172 of the holding mechanism 17 is held by the fixing holding member 176. At this stage, the environment is ready to receive the spatial optical signal transmitted from the communication target.

The control unit 19 receives a spatial optical signal from the communication target using the optical receiver 121 of the receiver 12. The control unit 19 acquires a signal output from the optical receiving element of the optical receiver 121. The control unit 19 amplifies the signal from the optical receiving element. Details of the signal processing by the control unit 19 will not be explained here. The control unit 19 decodes the amplified signal. The signal decoded by the control unit 19 is used for any purpose. There are no particular limitations on the use of the signal decoded by the control unit 19.

[Rotation holding member]
Next, specific examples of the rotation holding member 175 will be described. Six examples will be given below. The rotation holding member 175 is not limited to the following examples.

<First Example>
6 to 7 are conceptual diagrams for explaining a first example of the rotational holding member 175 (rotational holding member 1751). FIG. 6 to FIG. 7 are diagrams seen from a side perspective. The rotational holding member 1751 has a shape with multiple conical projections protruding downward. The rotational holding member 1751 is made of a material that is softer than the first fixed end 171. For example, the material of the rotational holding member 1751 is resin. When the coil of the solenoid 170 is not energized, the movable core 173 is in a state of falling downward (FIG. 6). When the coil of the solenoid 170 is energized, the movable core 173 moves upward, and the first fixed end 171 pierces the rotational holding member 1751 (FIG. 7). In this state, when the rotating base 185 of the rotation mechanism 18 is rotated, the direction of the light receiving surface of the light receiver 121 disposed on the support 122 fixed to the holding rod 123 changes in accordance with the movement of the holding rod 123 on which the holding mechanism 17 is disposed. When the power supply to the coil of the solenoid 170 is released, the first fixed end 171 comes off the rotation holding member 1751 in response to the elastic force of the spring 174 and gravity, and the movable core 173 falls downward ( FIG. 6 ).

<Second Example>
8 to 9 are conceptual diagrams for explaining a second example of the rotational holding member 175 (rotational holding member 1752). FIGS. 8 to 9 are views from a side perspective. The rotational holding member 1752 has a structure in which an elastic membrane that is recessed in response to the application of pressure is arranged facing downward. The rotational holding member 1752 elastically deforms in response to contact with the first fixed end 171. For example, the material of the rotational holding member 1752 is resin. When the coil of the solenoid 170 is not energized, the movable core 173 is in a state of dropping downward (FIG. 8). When the coil of the solenoid 170 is energized, the movable core 173 moves upward, and the first fixed end 171 is pressed against the rotational holding member 1752 (FIG. 9). In this state, when the rotating base 185 of the rotation mechanism 18 is rotated, the direction of the light receiving surface of the light receiver 121 disposed on the support 122 fixed to the holding rod 123 changes in accordance with the movement of the holding rod 123 on which the holding mechanism 17 is disposed. When the power supply to the coil of the solenoid 170 is released, the first fixed end 171 comes off the rotation holding member 1752 in response to the elastic force of the spring 174 and gravity, and the movable core 173 falls downward ( FIG. 8 ).

<Third Example>
10 to 11 are conceptual diagrams for explaining a third example of the rotation holding member 175 (rotation holding member 1753). FIG. 10 to FIG. 11 are diagrams seen from a side perspective. The rotation holding member 1753 is made of a material into which the first fixed end 171 is stuck. For example, the material of the rotation holding member 1753 is a resin that is softer than the first fixed end 171. When the coil of the solenoid 170 is not energized, the movable core 173 is in a state of dropping downward (FIG. 10). When the coil of the solenoid 170 is energized, the movable core 173 moves upward, and the first fixed end 171 is stuck into the rotation holding member 1753 (FIG. 11). In this state, when the rotating table 185 of the rotation mechanism 18 is rotated, the direction of the light receiving surface of the light receiver 121 arranged on the support 122 fixed to the holding rod 123 changes according to the movement of the holding rod 123 on which the holding mechanism 17 is arranged. When the current supply to the coil of the solenoid 170 is released, the first fixed end 171 comes off the rotation holding member 1753 due to the elastic force of the spring 174 and gravity, and the movable core 173 falls downward (FIG. 10).

<Fourth Example>
12 and 13 are conceptual diagrams for explaining a fourth example of the rotation holding member 175 (rotation holding member 1754). FIG. 12 and FIG. 13 are diagrams seen from a side perspective. The rotation holding member 1754 has a mesh through which the tip of the first fixed end 171 penetrates. For example, the material of the mesh of the rotation holding member 1754 is metal or resin. When the coil of the solenoid 170 is not energized, the movable core 173 is in a state of dropping downward (FIG. 12). When the coil of the solenoid 170 is energized, the movable core 173 moves upward, and the first fixed end 171 pierces the mesh of the rotation holding member 1754 (FIG. 13). In this state, when the rotating table 185 of the rotation mechanism 18 is rotated, the direction of the light receiving surface of the light receiver 121 arranged on the support 122 fixed to the holding rod 123 changes according to the movement of the holding rod 123 on which the holding mechanism 17 is arranged. When the current supply to the coil of the solenoid 170 is released, the first fixed end 171 comes off the rotation holding member 1754 due to the elastic force of the spring 174 and gravity, and the movable core 173 falls downward (FIG. 12).

<Fifth Example>
14 to 15 are conceptual diagrams for explaining a fifth example of the rotation holding member 175 (rotation holding member 1755). FIG. 14 to FIG. 15 are diagrams seen from a side perspective. In the fifth example, a first fixed end 1715 is arranged at the upper end of the movable core 173 instead of the first fixed end 171. The material of the first fixed end 1715 is not particularly limited as long as it does not interfere with the magnetic force of the movable core 173 magnetized by energizing the coil. For example, the material of the first fixed end 1715 is a metal or resin that is easily magnetized. The rotation holding member 1755 is a member to which the movable core 173 magnetized by energizing the coil is attached. For example, the material of the rotation holding member 1755 is a metal that is easily magnetized. When the coil of the solenoid 170 is not energized, the movable core 173 is in a state of falling downward (FIG. 14). When the coil of the solenoid 170 is energized, the magnetized movable core 173 moves upward and the first fixed end 1715 comes into contact with the rotation holding member 1755 (FIG. 15). In this state, when the turntable 185 of the rotation mechanism 18 is rotated, the direction of the light receiving surface of the light receiver 121 disposed on the support 122 fixed to the holding rod 123 changes in accordance with the movement of the holding rod 123 on which the holding mechanism 17 is disposed. When the coil of the solenoid 170 is de-energized, the first fixed end 1715 comes off the rotation holding member 1755 in accordance with the elastic force of the spring 174 and gravity, and the movable core 173 falls downward (FIG. 14).

<Sixth Example>
16 to 18 are conceptual diagrams for explaining a sixth example of the rotation holding member 175 (rotation holding member 1756). FIGS. 16 to 17 are views from a side perspective. FIG. 18 is a conceptual diagram of the receiving device 1 as viewed from an upper perspective. FIG. 18 illustrates a state in which the ball lens 10, the ball lens receiver 111, and the support column 112 are removed. In the sixth example, a first fixed end 1716 is disposed at the upper end of the movable core 173 instead of the first fixed end 171. The material of the first fixed end 1716 is not particularly limited. For example, the material of the first fixed end 1716 is metal or resin. As shown in FIG. 18, the rotation holding member 1756 has a plurality of plate-shaped members whose long sides are arranged along the radial direction. The plurality of plate-shaped members are installed on the lower surface of the rotation holding member 1756. The material of the rotation holding member 1756 is not particularly limited. For example, the material of the rotation holding member 1756 is metal or resin. When the coil of the solenoid 170 is not energized, the movable core 173 is in a state of dropping downward (FIG. 16). When the coil of the solenoid 170 is energized, the movable core 173 moves upward, and the first fixed end 1716 enters between the two plate-like members of the rotation holding member 1756 (FIG. 17). In this state, when the rotating table 185 of the rotation mechanism 18 is rotated, the direction of the light receiving surface of the light receiver 121 arranged on the support 122 fixed to the holding rod 123 changes according to the movement of the holding rod 123 on which the holding mechanism 17 is arranged. When the coil of the solenoid 170 is de-energized, the movable core 173 drops downward according to the elastic force of the spring 174 and gravity (FIG. 16).

[Fixing holding member]
Next, the fixing holding member 176 will be described by giving specific examples. Three examples will be given below. The fixing holding member 176 is not limited to the following examples.

<First Example>
19 and 20 are conceptual diagrams for explaining a first example of the fixing holding member 176 (fixing holding member 1761). FIG. 19 and FIG. 20 are views from a side perspective. The fixing holding member 1761 has a shape in which a plurality of conical projections protrude upward. The fixing holding member 1761 is made of a material that is softer than the second fixed end 172. For example, the material of the fixing holding member 1761 is resin. When the coil of the solenoid 170 is in a non-energized state, the movable core 173 is in a state where it has fallen downward, and the second fixed end 172 is stuck into and held by the fixing holding member 1761 (FIG. 19). In this state, even if the rotating table 185 of the rotating mechanism 18 is rotated, the holding rod 123 on which the holding mechanism 17 is arranged does not move. When the coil of the solenoid 170 is energized, the movable core 173 moves upward and the first fixed end 171 is held by the fixing holding member 176 (FIG. 20). When the rotating table 185 of the rotation mechanism 18 is rotated in this state, the direction of the light receiving surface of the light receiver 121 arranged on the support 122 fixed to the holding rod 123 changes in accordance with the movement of the holding rod 123 on which the holding mechanism 17 is arranged. When the coil of the solenoid 170 is de-energized, the first fixed end 171 comes off the fixing holding member 176 in accordance with the elastic force of the spring 174 and gravity, and the movable core 173 falls downward. Then, the second fixed end 172 is stuck into and held by the fixing holding member 1761 (FIG. 19).

<Second Example>
21 and 22 are conceptual diagrams for explaining a second example of the fixing holding member 176 (fixing holding member 1762). FIG. 21 and FIG. 22 are diagrams seen from a side perspective. The fixing holding member 1762 has a mesh through which the tip of the second fixed end 172 penetrates. For example, the material of the mesh of the fixing holding member 1762 is metal or resin. When the coil of the solenoid 170 is not energized, the movable core 173 is in a state where it has fallen downward, and the second fixed end 172 is stuck into and held by the mesh of the fixing holding member 1762 (FIG. 21). In this state, even if the rotating table 185 of the rotation mechanism 18 is rotated, the holding rod 123 on which the holding mechanism 17 is arranged does not move. When the coil of the solenoid 170 is energized, the movable core 173 moves upward, and the first fixed end 171 is held by the fixing holding member 176 (FIG. 22). In this state, when the rotating base 185 of the rotating mechanism 18 is rotated, the direction of the light receiving surface of the light receiver 121 arranged on the support 122 fixed to the holding rod 123 changes in accordance with the movement of the holding rod 123 on which the holding mechanism 17 is arranged. When the current to the coil of the solenoid 170 is released, the first fixed end 171 comes off the fixing holding member 176 in response to the elastic force of the spring 174 and gravity, and the movable core 173 falls downward. Then, the second fixed end 172 is pierced and held by the mesh of the fixing holding member 1762 (FIG. 21).

<Third Example>
23 to 24 are conceptual diagrams for explaining a third example (fixing holding member 1763) of the fixing holding member 176. FIG. 23 to FIG. 24 are diagrams seen from a side perspective. A second fixed end 1723 is installed at the lower end of the movable core 173. Either a hook or a loop of a hook-and-loop fastener is formed on the upper surface of the fixing holding member 1763 and the lower surface of the second fixed end 1723. When a hook is formed on the upper end surface of the fixing holding member 1763, a loop is formed on the lower end surface of the second fixed end 172. When a loop is formed on the upper end surface of the fixing holding member 1763, a hook is formed on the lower end surface of the second fixed end 172. For example, the second fixed end 1723 and the fixing holding member 1763 are made of resin. When the coil of the solenoid 170 is not energized, the movable core 173 is in a state where it has fallen downward, and the second fixed end 1723 is held by the fixing holding member 1763 (FIG. 23). In this state, even if the rotating base 185 of the rotating mechanism 18 is rotated, the holding rod 123 on which the holding mechanism 17 is arranged does not move. When the coil of the solenoid 170 is energized, the second fixed end 1723 is released from the fixing holding member 1763, the movable core 173 moves upward, and the first fixed end 171 is held by the fixing holding member 1763 (FIG. 24). In this state, when the rotating base 185 of the rotating mechanism 18 is rotated, the direction of the light receiving surface of the light receiver 121 arranged on the support 122 fixed to the holding rod 123 changes according to the movement of the holding rod 123 on which the holding mechanism 17 is arranged. When the coil of the solenoid 170 is de-energized, the first fixed end 171 is released from the fixing holding member 176 according to the elastic force of the spring 174 and gravity, and the movable core 173 falls downward. Then, the second fixed end 1723 is held by a fixing holding member 1763 (FIG. 23).

(Operation)
Next, the operation of the receiving device 1 of this embodiment will be described with reference to the drawings. Fig. 25 is a flowchart for explaining the operation of the receiving device 1. The flowchart in Fig. 25 relates to the operation at the stage of establishing communication with a communication target. In the following description based on the flowchart in Fig. 25, the control unit 19 provided in the receiving device 1 is the subject of operation. The control unit 19 adjusts the position of the holding mechanism 17 in response to a change from the initial position of the holding mechanism 17 that has been set in advance.

In FIG. 25, first, when the control unit 19 detects a communication target (Yes in step S11), it identifies the direction of the detected communication target (step S12). If the control unit 19 has not detected a communication target (No in step S11), it continues step S11 until a communication target is detected.

After step S12, the control unit 19 selects the receiver 12 to be used for communication with the communication target in the identified direction (step S13).

Next, the control unit 19 energizes the coil of the solenoid 170 of the holding mechanism 17 that is paired with the selected receiver 12 (step S14). At this stage, the first fixed end 171 of the holding mechanism 17 is held by the rotating holding member 175.

Next, the control unit 19 drives the rotation mechanism 18 to orient the light receiving surface of the optical receiver 121 of the selected receiver 12 in the direction of the communication target (step S15). The control unit 19 drives the rotation mechanism 18 and controls it so that the light receiving surface of the optical receiver 121, sandwiching the ball lens 10, is oriented in the direction of the communication target.

Next, the control unit 19 de-energizes the coil of the solenoid 170 of the holding mechanism 17 (step S16). The second fixed end 172 of the holding mechanism 17 is held by the fixing holding member 176. At this stage, the communication environment between the receiving device 1 and the communication target is established.

Next, the control unit 19 receives the spatial light signal using the optical receiver 121 of the receiver 12 whose position has been adjusted (step S17). The control unit 19 executes various processes according to the received spatial light signal.

As described above, the receiving device of this embodiment includes a ball lens, at least one receiver, a holding mechanism, a rotation mechanism, and a control unit. The holding mechanism, the rotation mechanism, and the control unit constitute a position adjustment device. The ball lens is a spherical lens. The receiver corresponds to a communication device. The receiver has at least one light receiving element. The receiver is arranged to move in a ring shape in the light collecting area of the ball lens in accordance with the movement of the holding mechanism of the associated position adjustment device. The holding mechanism is arranged in each of the multiple receivers. The holding mechanism has a solenoid. A movable core is inserted into the coil of the solenoid. The movable core includes a first fixed end facing the rotating holding member and a second fixed end facing the fixed holding member. The rotating mechanism is provided with an annular rotating holding member. The movable core inserted into the coil of the solenoid of the holding mechanism is arranged to be movable along the vertical direction. The first fixed end is directed upward, and the second fixed end is directed downward. When electricity is applied to the coil, the movable core moves upward, and the first fixed end is held by the rotation holding member arranged above. Meanwhile, when electricity is removed from the coil, the movable core moves toward the fixed holding member and separates from the rotation holding member. The control unit controls the coil of a solenoid in a holding mechanism in which a receiver used for communication with a communication target is arranged, and rotates the rotation mechanism to orient the communication direction of the receiver toward the communication target.

The receiving device of this embodiment rotates the rotation mechanism while the coil of the solenoid of the holding mechanism in which the receiver that receives the spatial light signal from the communication target is placed is energized, thereby directing the receiving direction of the receiver towards the communication target. According to this embodiment, the receiving direction of the receiver can be adjusted to face any direction within the rotation plane of the rotation mechanism. In other words, according to this embodiment, the position of the receiver can be adjusted to correspond to any direction along the same plane.

In one aspect of this embodiment, the first fixed end has a shape with multiple protrusions. The rotation holding member has a structure that temporarily holds the first fixed end. In this aspect, the first fixed end is temporarily held by the rotation holding member when the solenoid coil is energized. According to this aspect, by rotating the rotation mechanism with the first fixed end temporarily held by the rotation holding member, the receiving direction of the receiver can be adjusted to any direction within the rotation plane of the rotation mechanism.

Second Embodiment
Next, a receiving device according to a second embodiment will be described with reference to the drawings. The receiving device of this embodiment differs from the first embodiment in the structure of the position adjustment device. In the following, the description of the same parts as the first embodiment may be omitted.

(composition)
FIG. 26 is a conceptual diagram showing an example of the configuration of the receiving device 2 according to this embodiment. The receiving device 2 includes a ball lens 20, a receiver 22, a holding mechanism 27, a rotation mechanism 28, and a control unit 29. The holding mechanism 27, the rotation mechanism 28, and the control unit 29 constitute a position adjustment device. The receiver 22 is a form of a communication device. The receiver 22 and the holding mechanism 27 are paired. The receiving device 2 includes a plurality of pairs of the receiver 22 and the holding mechanism 27. FIG. 26 is a cross-sectional view of the receiving device 2 as seen from a side perspective. The receiving device 2 is stored inside a housing (not shown) in which an opening or window for receiving a spatial optical signal is formed. FIG. 26 is conceptual and does not accurately represent the shape of each component or the positional relationship between the components.

The ball lens 20 has the same configuration as the ball lens 10 of the first embodiment. The ball lens 20 is a spherical lens. The ball lens 20 focuses the incident spatial optical signal. The light (also called optical signal) derived from the spatial optical signal focused by the ball lens 20 is focused toward the focusing area of the ball lens 20. The ball lens 20 is supported by a ball lens receiver 211 that has a shape of an upside-down spherical crown. The ball lens receiver 211 is disposed on the top of a support column 212 that is erected in the center of a disk-shaped base 210. The periphery of the support column 212 is surrounded by a cylindrical column 213. A fixing holder 276 is disposed on the side of the cylindrical column 213. The fixing holder 276 has the same configuration as the fixing holder 176 of the first embodiment. The fixing holder 276 is disposed in a ring shape in accordance with the side of the cylindrical column 213 with the holding surface facing outward.

A rotation mechanism 28 is disposed on the upper surface of the base 210. The rotation mechanism 28 has the same configuration as the rotation mechanism 18 of the first embodiment. The rotation mechanism 28 has a motor 281, a rotation shaft 282, a tire 283, an annular track 284, and a rotating table 285. The rotation shaft 282 is the motor shaft of the motor 281. A tire 283 is attached to the rotation shaft 282. The side of the tire 283 is disposed so as to be in contact with the side of the rotating table 285. The annular track 284 is an annular track centered on the support pillar 212. A groove is formed on the upper surface of the annular track 284, which is recessed in an annular shape centered on the support pillar 212. The rotating table 285 is a cylindrical table that is open at the bottom. An opening is formed on the upper surface of the rotating table 285 so as not to interfere with the support pillar 222 of the receiver 22. The lower end of the rotating table 285 forms a ring. The lower end of the rotating table 285 is fitted into a groove on the upper surface of the annular track 284. The rotating table 285 is arranged to be rotatable along the groove on the upper surface of the annular track 284. In accordance with the rotation of the rotating shaft 282 in response to the drive of the motor 281 by the drive function included in the control unit 29, the tire 283 attached to the rotating shaft 282 rotates. In accordance with the rotation of the tire 283, the rotating table 285 rotates.

Furthermore, a first annular orbit 225 and a second annular orbit 226 are arranged on the upper surface of the base 210. The first annular orbit 225 and the second annular orbit 226 are circular orbits centered on the support pillar 212. The first annular orbit 225 is arranged outside the second annular orbit 226. The first annular orbit 225 and the second annular orbit 226 are arranged concentrically. A circular groove centered on the support pillar 212 is formed on the upper surfaces of the first annular orbit 225 and the second annular orbit 226. A first support 278 is fitted into the groove on the upper surface of the first annular orbit 225. The first support 278 slides along the groove on the upper surface of the first annular orbit 225. A second support 279 is fitted into the groove on the upper surface of the second annular orbit 226. The second support 279 slides along the groove on the upper surface of the second annular orbit 226. The first support 278 and the second support 279 are members that movably support the solenoid 270 of the holding mechanism 27. The distance between the first annular orbit 225 and the second annular orbit 226 is set to be the same as the distance between the first support 278 and the second support 279.

A rotation holding member 275 is installed on the inner surface of the rotating table 285 in alignment with the position of the first fixed end 271 of the holding mechanism 27. The rotation holding member 275 has a configuration similar to that of the rotation holding member 175 of the first embodiment. The fixed holding member 276 is arranged in a ring shape in alignment with the inner surface of the rotating table 285, with the holding surface facing inward. When the rotating table 285 rotates with the first fixed end 271 of any holding mechanism 27 held by the rotation holding member 275, the position of the receiver 22 paired with that holding mechanism 27 is changed.

A circuit area 219 is formed inside the base 210. A control unit 29 is disposed in the circuit area 219. The control unit 29 has a driving function for driving the holding mechanism 27 and the rotation mechanism 28, and a receiving function for processing the spatial light signal received by the receiver 22. Wiring between the components of the receiving device 2 and the control unit 29 is omitted. The control unit 29 may be disposed externally instead of in the circuit area 219. For example, the control unit 29 may be implemented in a server or cloud connected via a communication network such as the Internet or an intranet.

Receiver 22 has photodetector 221 and support 222. Photodetector 221 has the same configuration as photodetector 121 of the first embodiment. Support 222 has the same configuration as support 122 of the first embodiment. Photodetector 221 is positioned in the light-focusing area of ball lens 20 by support 222. The light-receiving surface of photodetector 221 faces ball lens 20. Support 222 is a rod-shaped pillar having two bent points when viewed from the side. Photodetector 221 is positioned above support 222 in a position facing ball lens 20. The lower end of support 222 is fixed to the outer upper part of solenoid 270 of holding mechanism 27. In response to the movement of the first support 278 and the second support 279 along the first annular orbit 225 and the second annular orbit 226, the support 222 supporting the optical receiver 221 moves around the ball lens 20. As a result, the light receiving direction of the light receiving surface of the optical receiver 221 is changed.

The optical receiver 221 is disposed in a position facing the ball lens 20 above the support 222. At least one light receiving element is disposed on the light receiving surface of the optical receiver 221. The light receiving element has a light receiving portion that receives an optical signal. The light receiving portion of the light receiving element is directed toward the ball lens 20. An optical signal focused by the ball lens 20 is incident on the light receiving portion of the light receiving element. The light receiving element receives the optical signal that is incident on the light receiving portion. The light receiving element converts the received optical signal into an electrical signal. The converted electrical signal is output to the control unit 29.

The holding mechanism 27 has a solenoid 270, a first fixed end 271, a second fixed end 272, a movable core 273, and a spring 274. The solenoid 270, the first fixed end 271, the second fixed end 272, the movable core 273, and the spring 274 have the same configuration as the corresponding configuration in the first embodiment. A coil (not shown) is arranged inside the solenoid 270. The movable core 273 is inserted inside the coil. The solenoid 270 is arranged sideways. In response to the passage of electricity through the coil, the movable core 273 inside the solenoid 270 moves along the radial direction of a circle centered on the support column 212. The first fixed end 271 is installed at the first end of the movable core 273. The first fixed end 271 has a shape with multiple conical protrusions protruding. A rotation holding member 275 is arranged on the side of the first fixed end 271. In this embodiment, when the coil is energized, the movable core 273 moves toward the outer periphery of the base 210. When the coil is energized, the first fixed end 271 is temporarily held by the rotation holding member 275. A second fixed end 272 is provided at the second end of the movable core 273. The second fixed end 272 has a shape with multiple cone-shaped protrusions protruding. A fixing holding member 276 is disposed on the side of the second fixed end 272. When the coil is not energized, the second fixed end 272 is held by the fixing holding member 276. A spring 274 is disposed around the movable core 273 in a portion exposed to the outside between the solenoid 270 and the second fixed end 272. The spring 274 is a helical coil spring.

Both ends of the solenoid 270 are sandwiched by a first support 278 and a second support 279. An opening through which the movable core 273 passes is formed in the first support 278 and the second support 279. The first support 278 and the second support 279 are members that support the solenoid 270 of the holding mechanism 27. The distance between the first support 278 and the second support 279 is set to be the same as the distance between the first annular orbit 225 and the second annular orbit 226. The lower end of the first support 278 is fitted into a groove on the upper surface of the first annular orbit 225. The lower end of the second support 279 is fitted into a groove on the upper surface of the second annular orbit 226. The solenoid 270 moves in accordance with the movement of the first support 278 and the second support 279 that move along the first annular orbit 225 and the second annular orbit 226.

When the rotating table 285 is rotated around the support column 212 while the first fixed end 271 is held by the rotating holding member 275, the position of the holding mechanism 27 changes. In response to the change in the position of the holding mechanism 27, the direction of the light receiving surface of the light receiver 221 arranged on the support column 222 fixed to the solenoid 270 changes.

When the coil of the solenoid 270 is de-energized, the movable core 273 moves toward the center of the base 210 in response to the elastic force of the spring 274, and the second fixed end 272 is held by the fixing holding member 276. When the second fixed end 272 is held by the fixing holding member 276, the receiver 22 on which the holding mechanism 27 is installed does not move.

The control unit 29 includes a driving function for driving the holding mechanism 27 and the rotation mechanism 28. The control unit 29 also includes a receiving function for processing the spatial light signal received by the receiver 22. For example, the control unit 29 is realized by a microcomputer having a processor and a memory.

In the stage of establishing communication with a communication target, the control unit 29 detects the communication target according to light received by any of the optical receivers 221 included in the multiple receivers 22. The control unit 29 identifies the direction of the detected communication target according to the state of light reception by the optical receiver 221. The control unit 29 selects the receiver 22 to be used for communication with the communication target in the identified direction. The control unit 29 energizes the solenoid 270 of the holding mechanism 27 paired with the selected receiver 22. In this state, the first fixed end 271 of the holding mechanism 27 is held by the rotation holding member 275.

The control unit 29 drives the rotation mechanism 28 to orient the light receiving surface of the optical receiver 221 of the selected receiver 22 toward the communication target. The control unit 29 adjusts the position of the optical receiver 221 according to changes from the initial position of the optical receiver 221. When the light receiving surface of the optical receiver 221 of the selected receiver 22 is orientated toward the communication target, the control unit 29 releases the power supply to the solenoid 270 of the holding mechanism 27 paired with the selected receiver 22. When the power supply is released, the second fixed end 272 of the holding mechanism 27 is held by the fixing holding member 276. At this stage, the environment is prepared for receiving a spatial optical signal from the communication target.

The control unit 29 receives a spatial optical signal from the communication target using the optical receiver 221 of the receiver 22. The control unit 29 acquires the signal output from the optical receiving element of the optical receiver 221. The control unit 29 amplifies the signal from the optical receiving element. Details of the signal processing by the control unit 29 will not be explained here. The control unit 29 decodes the amplified signal. The signal decoded by the control unit 29 is used for any purpose. There are no particular limitations on the use of the signal decoded by the control unit 29.

[Modification 1]
FIG. 27 is a conceptual diagram showing an example of the configuration of a modified example 1 (receiving device 2-1) related to the receiving device 2 of this embodiment. The receiving device 2-1 differs from the receiving device 2 (FIG. 26) in that it includes an encoder 227 and a scale 228. The encoder 227 and the scale 228 are an example of a position detector that detects the position of the receiver 22 (communication device). In addition, a circular ring-shaped column 217 is disposed on the periphery of the upper surface of the base 210 of the receiving device 2-1. The scale 228 is disposed on the upper surface of the ring-shaped column 217. The scale 228 is formed in a circular shape with the support column 212 as the center. A pattern for reading the position (position pattern) is formed on the upper surface of the scale 228.

The encoder 227 is disposed on the support 222 of the receiver 22. The encoder 227 is disposed in a position where it can read the scale 228. For example, the encoder 227 is disposed directly above the scale 228. The encoder 227 may also be disposed diagonally above the scale 228. The encoder 227 reads the position pattern and identifies the position of the receiver 22 on which the encoder 227 is disposed.

For example, the encoder 227 includes a light source, a lens, and a light receiving element. The light source emits light toward the position pattern below to read the position of the receiver 22. The light reflected at the position of the position pattern is focused by the lens on the light receiving surface of the light receiving element. The light receiving element receives the light focused by the lens. The light received by the light receiving element is converted into an electrical signal and output to the control unit 29. The control unit 29 identifies the position of the receiver 22 according to the pattern of the electrical signal.

According to this modified example, the position of the receiver 22 can be determined according to the position pattern of the scale 228 read by the encoder 227. Therefore, according to this modified example, the position of the receiver 22 can be accurately adjusted.

[Modification 2]
Fig. 28 is a conceptual diagram of the configuration of a modified example 2 (receiving device 2-2) related to the receiving device 2 of this embodiment. The receiving device 2-2 differs from the receiving device 2 (Fig. 26) in that it includes a fisheye camera 290. The fisheye camera 290 is an example of a position detector that detects the position of the receiver 22 (communication device). The receiving device 2-2 is disposed inside a housing 200. The side surface of the housing 200 is transparent in the wavelength band of the spatial optical signal.

The fisheye camera 290 captures an image derived from light arriving from the horizontal direction and an image of the receiving device 2-2 arranged inside the housing 200. FIG. 29 is a conceptual diagram for explaining the image captured by the fisheye camera 290. FIG. 29 shows an internal region where an image inside the housing 200 is detected, and an external region where an image outside the housing 200 is detected. The ball lens 20 and the receiver 22 are reflected in the internal region. The spatial light signal (notification light) transmitted from the communication target is reflected in the external region. For example, the receiver 22 is moved from position A to position B opposite the position of the notification light. By controlling in this way, the light receiving surface of the light receiver 221 included in the receiver 22 moved to position B is directed toward the communication target.

In this modified example, an image captured by the fisheye camera 290 is used to detect a spatial light signal (notification light) transmitted from the communication target. In this modified example, the position of the receiver 22 is changed according to the position of the detected notification light. Therefore, according to this modified example, the position of the receiver 22 can be accurately adjusted to match the position of the communication target.

As described above, the receiving device of this embodiment includes a ball lens, at least one receiver, a holding mechanism, a rotation mechanism, and a control unit. The holding mechanism, the rotation mechanism, and the control unit constitute a position adjustment device. The ball lens is a spherical lens. The receiver corresponds to a communication device. The receiver has at least one light receiving element. The receiver is arranged to move in a circular shape in the light collecting area of the ball lens in accordance with the movement of the holding mechanism of the associated position adjustment device. The holding mechanism has a solenoid. A movable core is inserted into the coil of the solenoid. The movable core includes a first fixed end facing the rotation holding member and a second fixed end facing the fixed holding member. An annular rotation holding member is installed in the rotation mechanism. The movable core inserted into the coil of the solenoid of the holding mechanism is arranged to be movable along the horizontal direction. The first fixed end is oriented in the circumferential direction of the rotation mechanism. The second fixed end is oriented in the rotation axis direction of the rotation mechanism. In response to energization of the coil, the movable core moves in the direction of the rotation axis of the rotation mechanism, and the first fixed end is held by a rotation holding member arranged in the direction of the rotation axis of the rotation mechanism. Meanwhile, in response to de-energization of the coil, the movable core moves toward the fixed holding member and separates from the rotation holding member. The control unit controls the energization of the solenoid coil of the holding mechanism in which the receiver used for communication with the communication target is arranged, and rotates the rotation mechanism to orient the communication direction of the receiver toward the communication target.

The receiving device of this embodiment rotates the rotation mechanism while the coil of the solenoid of the holding mechanism in which the receiver that receives the spatial light signal from the communication target is placed is energized, thereby directing the receiving direction of the receiver towards the communication target. According to this embodiment, the receiving direction of the receiver can be adjusted to face any direction within the rotation plane of the rotation mechanism. In other words, according to this embodiment, the position of the receiver can be adjusted to correspond to any direction along the same plane.

In one aspect of this embodiment, the receiving device is provided with a position detector that detects the position of the receiver (communication device). The control unit aligns the communication direction of the receiver with the communication target based on the position of the receiver detected by the position detector. According to this aspect, the position of the receiver can be adjusted based on the position of the receiver detected by the position detector. Therefore, according to this aspect, the position of the receiver can be accurately adjusted to match the position of the communication target.

Third Embodiment
Next, a transmitting device according to a third embodiment will be described with reference to the drawings. The transmitting device of this embodiment includes a position adjustment device and a rotation mechanism similar to those of the first and second embodiments. In the following, the description of the same parts as those of the first and second embodiments may be omitted. In the following, an example is given in which the transmitting device of this embodiment is combined with the receiving device of the first and second embodiments. The transmitting device of this embodiment identifies the direction of a communication target based on the spatial optical signal received by the receiving device of the first and second embodiments, and prepares an environment for transmitting a spatial optical signal toward the communication target.

(composition)
FIG. 30 is a conceptual diagram showing an example of the configuration of the transmitting device 3 according to this embodiment. The transmitting device 3 includes a light source 31, a spatial light modulator 32, a light-transmitting mirror 33, a holding mechanism 37, a rotation mechanism 38, and a control unit 39. The holding mechanism 37, the rotation mechanism 38, and the control unit 39 constitute a position adjustment device. The light-transmitting mirror 33 is suspended by a suspension column 331 below a holding rod 333 on which the holding mechanism 37 is arranged. The light-transmitting mirror 33 and the suspension column 331 constitute a transmitter. The transmitter is one form of a communication device. The transmitter and the holding mechanism 37 are paired. The transmitting device 3 includes a plurality of pairs of a transmitter and a holding mechanism 37. FIG. 30 is a cross-sectional view of the transmitting device 3 as seen from a side perspective. The transmitting device 3 is stored inside a housing in which a window W for transmitting a spatial light signal is formed. FIG. 30 is conceptual and does not accurately represent the shape of each component or the positional relationship between the components.

The housing of the transmitter 3 is composed of a cover 300, a base 310, an annular body 380, and a cylindrical body 390. A support column 312 is suspended from the ceiling of the cover 300. A through hole is formed in the support column 312 in the vertical direction. A first annular bearing 315 is formed on the side of the support column 312. The cylindrical body 390 is placed on the base 310. A window W for projecting the projection light 303 is opened in the cylindrical body 390. The annular body 380 is placed on the upper part of the cylindrical body 390. The annular body 380 is placed at the same height as the first bearing 315. A second annular bearing 318 is formed on the inner side of the annular body 380. The bearing portions of the first bearing 315 and the second bearing 318 face each other at the same height. The first bearing 315 and the second bearing 318 movably support the holding mechanism 37.

A circular ring-shaped bearing 316 is disposed on the upper side of the support column 312. A groove is formed on the side of the bearing 316 along the horizontal plane. A circular ring-shaped rotating plate 385 of the rotation mechanism 38 is fitted into the groove on the side of the bearing 316. The rotating plate 385 is disposed so as to be rotatable around the support column 312. A circular ring-shaped rotating holding member 375 is disposed on the lower surface of the rotating plate 385. The rotating holding member 375 is formed above the first fixed end 371 of the holding mechanism 37.

A ring-shaped annular body 317 is disposed at the lower end of the support column 312. A ring-shaped fixing retaining member 376 is disposed on the outer edge of the upper surface of the ring-shaped body 317. The fixing retaining member 376 is formed below the second fixed end 372 of the retaining mechanism 37.

The base 310 houses a processing board (not shown) on which the control unit 39 is mounted. The control unit 39 may be disposed at a location other than the base 310. The control unit 39 includes a drive function for driving the holding mechanism 37 and the rotation mechanism 38, and a transmission function for transmitting a spatial light signal from the transmitter. Wiring between the components of the transmission device 3 and the control unit 39 is omitted.

The light source 31 emits illumination light 301. The light source 31 is arranged on the upper part of the support column 312 with the emission surface facing downward. The emission surface of the light source 31 is directed to the modulation section 320 of the spatial light modulator 32 arranged below through a through hole formed in the support column 312. The illumination light 301 emitted from the light source 31 passes through the through hole formed in the support column 312 and is irradiated to the modulation section 320 of the spatial light modulator 32. The light source 31 may be arranged inside the through hole formed in the support column 312.

The light source 31 includes at least one emitter (not shown). The emitter emits illumination light 301 according to the control of a communication control device (not shown). The illumination light 301 emitted from the light source 31 is irradiated onto the modulation section 320 of the spatial light modulator 32. The light source 31 may be a laser array in which multiple emitters are arranged in an array.

The emitter included in the light source 31 emits laser light in a predetermined wavelength band. The wavelength of the laser light emitted from the emitter is not particularly limited and may be selected according to the application. For example, the emitter emits laser light in a visible or infrared wavelength band. For example, near-infrared light of 800 to 1000 nanometers (nm) can be of a higher laser class than visible light, so sensitivity can be improved compared to visible light. For example, infrared light in the 1.55 micrometer (μm) wavelength band can use a higher output laser light source than near-infrared light in the 800 to 1000 nm wavelength band. As a laser light source that emits infrared light in the 1.55 μm wavelength band, an aluminum gallium arsenide phosphide (AlGaAsP)-based laser light source or an indium gallium arsenide (InGaAs)-based laser light source can be used. The longer the wavelength of the laser light, the larger the diffraction angle can be and the higher the energy can be set. For example, the emitter may be a surface-emitting device such as a PCSEL (Photonic Crystal Surface Emitting Laser) type laser.

Each of the multiple emission sections is associated with one of the multiple modulation regions set in the modulation section 320 of the spatial light modulator 32. The illumination light 301 emitted from each of the multiple emission sections travels toward the associated modulation region.

The spatial light modulator 32 is a phase modulation type spatial light modulator. The spatial light modulator 32 has a modulation section 320. The spatial light modulator 32 is disposed below the light source 31. The spatial light modulator 32 is disposed at a position where modulated light 302, which is obtained by modulating the illumination light 301 emitted from the light source 31, is reflected toward the reflecting surface 330 of the light-transmitting mirror 33. The traveling direction of the modulated light 302 is controlled according to the pattern (phase image) set in the modulation section 320.

For example, the spatial light modulator 32 is realized by a spatial light modulator using a ferroelectric liquid crystal, a homogeneous liquid crystal, a vertically aligned liquid crystal, or the like. For example, the spatial light modulator 32 can be realized by LCOS (Liquid Crystal on Silicon). The spatial light modulator 32 may also be realized by a MEMS (Micro Electro Mechanical System). In a phase modulation type spatial light modulator 32, the energy can be concentrated on the image portion by operating to sequentially switch the locations used for projecting the projection light 303. Therefore, when a phase modulation type spatial light modulator 32 is used, if the output of the emitter included in the light source 31 is the same, the image can be displayed brighter than with other methods.

At least one modulation area is set in the modulation section 320 of the spatial light modulator 32. The number of modulation areas set in the modulation section 320 is set according to the number of emitters included in the light source 31. Each of the multiple modulation areas is associated with one of the multiple emitters included in the light source 31. Each of the multiple modulation areas is irradiated with illumination light 301 derived from the laser light emitted from the associated emitter. However, as long as the illumination light 301 derived from the laser light emitted from the emitter is incident on the modulation surface of the modulation area, the correspondence between the modulation area and the emitter is not particularly limited. In addition, the number of modulation areas set in the modulation section 320 may be different from the number of emitters included in the light source 31.

The modulation area is divided into a plurality of areas (also called tiling). For example, the modulation area R is divided into square or rectangular areas (also called tiles). The same phase image is assigned to each of the plurality of tiles. Each of the plurality of tiles is composed of a plurality of pixels. A phase image corresponding to the image to be projected is set to each of the plurality of tiles. A phase image is tiled to each of the plurality of tiles assigned to the modulation area. For example, a phase image generated in advance is set to each of the plurality of tiles. When the illumination light 301 is irradiated to the modulation area with the same phase image set to the plurality of tiles, modulated light 302 that forms an image corresponding to the phase image of each tile is emitted. The more tiles that are set in the modulation area, the clearer the image that can be displayed, but the resolution decreases when the number of pixels in each tile decreases. Therefore, the size and number of tiles set in the modulation area are set according to the application.

In each of the multiple modulation areas, a pattern (also called a phase image) corresponding to the image displayed by the projected light 303 is set according to the control of the communication control device. In each of the multiple modulation areas, a pattern (phase image) is set. The illumination light 301 irradiated to each of the multiple modulation areas is modulated according to the pattern (phase image) set in the modulation area. The modulated light 302 modulated in each of the multiple modulation areas proceeds toward the reflecting surface 330 of the light-transmitting mirror 33.

For example, a shield (not shown) may be disposed after the spatial light modulator 32. The shield is a frame that shields unnecessary light components contained in the modulated light 302 and defines the outer edge of the display area of the projected light 303. For example, the shield is an aperture. In such an aperture, a slit-shaped opening is formed in a portion that passes light (desired light) that forms a desired image. The desired light is first-order diffracted light. The shield passes the desired light and shields unnecessary light components. For example, the shield shields zero-order light contained in the modulated light 302, unnecessary first-order light that appears in a position point-symmetrical to the desired light with the zero-order light as the center, and ghost images that include second-order or higher-order light. Details of the shield are omitted.

The light-sending mirror 33 is a reflector having a reflecting surface 330. The reflecting surface 330 is a flat surface. The reflecting surface 330 may have a curvature according to the projection angle of the projected light 303. For example, the reflecting surface 330 may have a shape that combines a curved surface and a flat surface. The light-sending mirror 33 is disposed after the spatial light modulator 32. The light-sending mirror 33 is disposed at the lower end of the suspension column 331. The light-sending mirror 33 is suspended below the holding rod 333 by the suspension column 331. The holding rod 333 has a first end 335 and a second end 336 that are formed in a spherical shape. The first end 335 is inserted into the bearing portion of the first bearing 315. The second end 336 is inserted into the bearing portion of the second bearing 318. The first end 335 slides in the bearing portion of the first bearing 315 in response to the movement of the holding rod 333. Similarly, the second end 336 slides on the bearing portion of the second bearing 318 in response to the movement of the holding rod 333. That is, the suspension pole 331 supporting the light-sending mirror 33 moves around the support pole 312 in response to the movement of the holding rod 333. As a result, the orientation of the reflective surface 330 of the light-sending mirror 33 is changed. The light-sending mirror 33 moves in accordance with the movement of the holding rod 333. The position of the light-sending mirror 33 is changed in response to the control of the control unit 39. In response to the detection of a spatial optical signal from the communication target, the position of the light-sending mirror 33 is changed so that the reflective surface 330 faces the direction from which the spatial optical signal comes.

The light-sending mirror 33 is arranged with its reflecting surface 330 facing obliquely toward the modulation section 320 of the spatial light modulator 32. The light-sending mirror 33 is arranged in the optical path of the modulated light 302. The modulated light 302 is irradiated onto the reflecting surface 330 of the light-sending mirror 33. The light reflected by the reflecting surface 330 (projected light 303) is projected as a spatial light signal. The projected light 303 is projected in a direction according to the irradiation position of the modulated light 302 on the reflecting surface 330 of the light-sending mirror 33. For example, a lens (not shown) may be arranged after the light-sending mirror 33 to limit the spread of the projected light 303.

The modulated light 302 modulated by the modulation section 320 of the spatial light modulator 32 contains unnecessary light components (also called unnecessary light). The unnecessary light is zero-order light and higher-order light contained in the modulated light 302. The light-sending mirror 33 is positioned at a position where the unnecessary light is not irradiated onto the reflecting surface 330. The reflecting surface 330 is irradiated with the light component to be projected (also called desired light) of the modulated light 302 modulated by the modulation section 320. The modulated light 302 irradiated onto the reflecting surface 330 is reflected by the reflecting surface 330. The light reflected by the reflecting surface 330 (projected light 303) is projected at an enlarged magnification according to the curvature of the reflecting surface 330.

The reflecting surface 330 of the light-transmitting mirror 33 can be oriented in any direction in the horizontal plane depending on the position of the holding rod 333 that supports the light-transmitting mirror 33. Therefore, the transmitting device 3 can project the projection light 303 in 360-degree directions in the horizontal plane by controlling the pattern (phase image) set in the modulation section 320 of the spatial light modulator 32. In addition, the transmitting device 3 can transmit the projection light 303 (spatial light signal) simultaneously toward communication targets located in multiple directions by associating multiple modulation regions set in the modulation section 320 with different directions.

The holding mechanism 37 has the same configuration as the holding mechanism 17 of the first embodiment. The holding mechanism 37 has a solenoid 370, a first fixed end 371, a second fixed end 372, a movable core 373, and a spring 374. The solenoid 370 is arranged on the holding rod 333 so as to penetrate vertically. A coil (not shown) is arranged inside the solenoid 370. The movable core 373 is inserted inside the coil. The movable core 373 is made of a material that is magnetized in response to the passage of electricity through the coil. The first fixed end 371 is installed at the upper end of the movable core 373. For example, the first fixed end 371 has a shape in which multiple conical protrusions protrude upward. A rotation holding member 375 is arranged above the first fixed end 371. In this embodiment, when the coil is energized, the movable core 373 moves upward, and the upper end portion of the first fixed end 371 is temporarily held by the rotation holding member 375. A second fixed end 372 is provided at the lower end of the movable core 373. For example, the second fixed end 372 has a shape with multiple cone-shaped projections protruding downward. A fixing holding member 376 is provided below the second fixed end 372. When the coil is not energized, the lower end portion of the second fixed end 372 is held by the fixing holding member 376. A spring 374 is provided around the movable core 373 in a portion exposed to the outside from below the solenoid 370. The spring 374 is a helical coil spring.

The rotation mechanism 38 has a motor 381, a rotating shaft 382, a tire 383, and a rotating plate 385. The rotating shaft 382 is the motor shaft of the motor 381. A tire 383 is attached to the rotating shaft 382. The material of the tire 383 is an elastic body such as rubber. The side of the tire 383 is arranged so that it is in contact with the side of the rotating plate 385. The rotating plate 385 is an annular plate. The inner annular part of the rotating plate 385 is fitted into the groove of the annular bearing 316. The rotating plate 385 is arranged rotatably along the groove of the annular bearing 316. The tire 383 attached to the rotating shaft 382 rotates in accordance with the rotation of the rotating shaft 382 in response to the drive of the motor 381 by the control unit 39. The rotating plate 385 rotates in accordance with the rotation of the tire 383.

A rotating holding member 375 is installed on the underside of the rotating plate 385 in accordance with the position of the first fixed end 371 of the holding mechanism 37. The rotating holding member 375 is formed in an annular shape centered on the support post 312. When the rotating plate 385 rotates with the first fixed end 371 of any holding mechanism 37 held by the rotating holding member 375, the position of the light-transmitting mirror 33 of the transmitter paired with that holding mechanism 37 is changed.

The control unit 39 includes a drive function for driving the holding mechanism 37 and the rotation mechanism 38. The control unit 39 also includes a transmission function for transmitting a spatial light signal toward the communication target. For example, the control unit 39 is realized by a microcomputer having a processor and memory. The control unit 39 prepares an environment for transmitting a spatial light signal toward the communication target based on the spatial light signal received by the receiving device combined with the transmitting device 3.

In the stage of establishing communication with the communication target, the control unit 39 identifies the direction of the communication target based on the reception of the spatial light signal by the receiving device. For example, the control unit 39 acquires a notification signal including information regarding the direction of the communication target from the receiving device. The control unit 39 selects a transmitter to be used for communication with the communication target. The control unit 39 energizes the coil of the solenoid 370 of the holding mechanism 37 paired with the selected transmitter. When the coil is energized, the movable core 373 inserted in the coil moves upward. In this state, the upper end portion of the first fixed end 371 of the holding mechanism 37 is held by the rotating holding member 375.

The control unit 39 drives the rotation mechanism 38 to direct the reflective surface 330 of the light-transmitting mirror 33 of the selected transmitter toward the communication target. The control unit 39 adjusts the position of the light-transmitting mirror 33 according to changes from the preset initial position of the light-transmitting mirror 33. When the reflective surface 330 of the light-transmitting mirror 33 of the selected transmitter is directed toward the communication target, the control unit 39 de-energizes the solenoid 370 of the holding mechanism 37 paired with the selected transmitter. When the power is released, the movable core 373 falls downward, and the second fixed end 372 of the holding mechanism 37 is held by the fixed holding member 376. At this stage, the environment is ready to transmit a spatial optical signal from the transmitting device 3 toward the communication target.

The control unit 39 controls the light source 31 and the spatial light modulator 32 to irradiate the reflective surface 330 of the light-sending mirror 33 with modulated light 302 that forms a spatial light signal. The projected light 303 reflected by the reflective surface 330 of the light-sending mirror 33 is transmitted as a spatial light signal toward the communication target. There are no particular limitations on the modulation method of the spatial light signal.

[Modification 3]
31 is a conceptual diagram showing an example of the configuration of a modified example 3 (transmitter 3-3) related to the transmitter 3 of this embodiment. The transmitter 3-3 differs from the transmitter 3 (FIG. 30) in that it has a direction detection receiver 35. The direction detection receiver 35 is an example of a position detector that detects the position of a transmitter (communicator) including a light-transmitting mirror 33. This modified example is used in combination with the first and second light-receiving devices.

The direction detection receiver 35 is installed at the end of the light transmitting mirror 33 that is closer to the spatial light modulator 32. At least one light receiving element is arranged on the light receiving surface of the direction detection receiver 35. The light receiving element has a configuration similar to that of the light receiving element included in the receiving device 1 of the first embodiment. The light receiving element has a light receiving portion that receives an optical signal. The light receiving portion of the light receiving element is directed toward the modulation portion 320 of the spatial light modulator 32. The position of the direction detection receiver 35 changes according to the movement of the holding rod 333.

When the communication control device (not shown) connected to the transmitting device 3-3 and the receiving device identifies the position of the communication target, it outputs an instruction signal to the transmitting device 3-3 including an instruction to irradiate the direction detection light 305 in the direction of the communication target. The direction detection light 305 is light that is irradiated in the direction of the communication target identified by the receiving device combined with the transmitting device 3-3. The transmission direction of the direction detection light 305 is set according to an instruction signal output from the communication control device connected to the transmitting device 3-3 and the receiving device. The transmitting device 3-3 sets a pattern in the modulation section 320 of the spatial light modulator 32 so that the direction detection light 305 is irradiated in the specified direction in response to the instruction signal from the communication control device. When the illumination light 301 is irradiated on the modulation section 320 in this state, the direction detection light 305 aligned with the direction of the communication target is emitted.

The control unit 39 changes the position of the light-transmitting mirror 33 of the transmitter used for communication with the communication target in accordance with the emission of the direction detection light 305. The control unit 39 adjusts the position of the light-transmitting mirror 33 in accordance with the change from the preset initial position of the light-transmitting mirror 33. When the light-transmitting mirror 33 reaches the optical path of the direction detection light 305, the direction detection light 305 is incident on the light receiving section of the light receiving element included in the direction detection receiver 35 installed on the light-transmitting mirror 33. The light receiving element receives the direction detection light 305 that has entered the light receiving section. The light receiving element converts the received optical signal into an electrical signal. The converted electrical signal is output to the control unit 39. In response to receiving the electrical signal, the control unit 39 detects that the transmitter used for communication with the communication target has moved to the irradiation position of the direction detection light 305.

FIG. 32 is a conceptual diagram for explaining an example of changing the position of the light-sending mirror 33 in accordance with the direction detection light 305. FIG. 32 shows an irradiation range _Rm of the modulated light 302 by the spatial light modulator 32. The irradiation range _Rm includes a direction designation light irradiation region _Rd and a signal light irradiation region _Rs . The direction designation light irradiation region _Rd is an area where the direction detection light 305 is irradiated. The signal light irradiation region _Rs is an area where the modulated light 302 used for communication is irradiated. FIG. 32 shows a state where the light-sending mirror 33 used for communication with the communication target has moved from position A to position B in accordance with the irradiation position of the direction detection light 305. One of the direction detection light receivers 35 is irradiated with the beam Bd of the direction detection light 305. The light-sending mirror 33 on which the direction detection light receiver 35 irradiated with the beam _Bd is installed is irradiated with the beam _Bs of the modulated light 302 modulated by the modulation section 320 of the spatial light modulator ₃₂ . The light reflected by the light-sending mirror 33 irradiated with the beam _Bs is transmitted as a spatial light signal (projected light 303 ).

According to this modified example, by adjusting the position of the light-sending mirror 33 to match the irradiation position of the direction detection light 305, the transmitter in which the light-sending mirror 33 is installed can be accurately adjusted to face the communication target.

[Modification 4]
33 to 34 are conceptual diagrams showing an example of the configuration of Modification 4 (transmitter 3-4) related to the transmitter 3 of this embodiment. FIG. 33 is a cross-sectional view of the transmitter 3-4 seen from a side perspective. FIG. 34 is a conceptual diagram showing a portion of a window W of a cylinder 390 cut in the vicinity of the light-transmitting mirror 33 along a horizontal plane. FIG. 34 is a view seen from an upper perspective. The transmitter 3-4 differs from the transmitter 3 (FIG. 30) in that it includes a pillar avoidance mirror 34 for transmitting a spatial optical signal while avoiding a pillar P of the cylinder 390 of the transmitter 3-4.

As shown in FIG. 34, there are two pillars P on the cylindrical body 390 of the transmitting device 3-4. If the communication target is located in the direction of the pillar P, the light reflected by the light-transmitting mirror 33 will be blocked by the pillar P. For this reason, the transmitting device 3-4 is configured with a pillar avoidance mirror 34 to avoid the pillar P. The pillar avoidance mirror 34 is suspended below the ring-shaped body 317 by a suspension pole 341. The pillar avoidance mirror 34 is installed below the light-transmitting mirror 33. Unlike the light-transmitting mirror 33, the position of the pillar avoidance mirror 34 is fixed. In the example of FIG. 34, a total of four pillar avoidance mirrors 34 are placed, two on each side of each of the two pillars P. The reflective surfaces 340 of the pillar avoidance mirror 34 are directed toward the outside of the cylindrical body 390.

As shown in FIG. 33, in a position that is not blocked by the pillar P, the projected light 303 reflected by the reflecting surface 330 of the light-transmitting mirror 33 is transmitted as a spatial light signal. In a position that is blocked by the pillar P, the projected light 304 reflected by the reflecting surface 340 of the pillar avoidance mirror 34 is transmitted as a spatial light signal.

According to this modified example, spatial optical signals can be transmitted in directions where there is a pillar P as well as in directions where there is no pillar P. In practice, it is necessary to install wiring connecting the components above the transmitting device 3 with the components below. Also, in order to ensure the strength of the housing of the transmitting device 3, a structure is required to reinforce part of the window W. According to this modified example, spatial optical signals can be transmitted in any direction along the horizontal plane while ensuring the placement and strength of the wiring.

(Operation)
Next, the operation of the transmitting device 3 of this embodiment will be described with reference to the drawings. Fig. 35 is a flowchart for explaining the operation of the transmitting device 3. The flowchart in Fig. 35 relates to the operation at the stage of establishing communication with a communication target. In the following description based on the flowchart in Fig. 35, the control unit 39 provided in the transmitting device 3 is the subject of operation. The control unit 39 adjusts the position of the holding mechanism 37 in response to a change from the initial position of the holding mechanism 37 that has been set in advance.

In FIG. 35, first, the control unit 39 identifies the direction of the communication target in response to reception of the spatial light signal by the receiving device (step S31).

Then, the control unit 39 selects a transmitter to be used for communication with the communication target in the identified direction (step S32).

Next, the control unit 39 energizes the coil of the solenoid 370 of the holding mechanism 37 paired with the selected transmitter (step S33). At this stage, the first fixed end 371 of the holding mechanism 37 is held by the rotating holding member 375.

Then, the control unit 39 drives the rotation mechanism 38 to orient the reflecting surface 330 of the light-transmitting mirror 33 of the selected transmitter in the direction of the communication target (step S34).

Next, the control unit 39 de-energizes the coil of the solenoid 370 of the holding mechanism 37 (step S35). At this stage, the communication environment between the transmitting device 3 and the communication target is established.

Then, the control unit 39 receives the spatial light signal using the light-transmitting mirror 33 of the transmitter whose position has been adjusted (step S36). The control unit 39 executes various processes according to the received spatial light signal.

As described above, the transmitting device of this embodiment includes at least one light source, a spatial light modulator, at least one transmitter, a holding mechanism, a rotation mechanism, and a control unit. The holding mechanism, the rotation mechanism, and the control unit constitute a position adjustment device. The spatial light modulator has a modulation unit that modulates the illumination light emitted from the light source. The transmitter corresponds to a communication device. The transmitter includes a light-transmitting mirror that is irradiated with modulated light modulated by the modulation unit and has a reflective surface that reflects the modulated light in any direction along a horizontal plane. The transmitter is arranged to move in a ring shape around the optical axis of the illumination light in accordance with the movement of the holding mechanism of the associated position adjustment device. The holding mechanism is arranged in each of the multiple transmitters. The holding mechanism has a solenoid. A movable core is inserted into the coil of the solenoid. The movable core includes a first fixed end facing the rotating holding member and a second fixed end facing the fixed holding member. A ring-shaped rotating holding member is installed in the rotation mechanism. The movable core inserted into the coil of the solenoid of the holding mechanism is arranged to be movable along the vertical direction. The first fixed end faces upward, and the second fixed end faces downward. When electricity is applied to the coil, the movable core moves upward, and the first fixed end is held by a rotation holding member arranged above. Meanwhile, when electricity is removed from the coil, the movable core moves towards the fixed holding member and moves away from the rotation holding member. The control unit executes control to apply electricity to the coil of the solenoid of the holding mechanism in which a transmitter used for communication with a communication target is arranged, and rotates the rotation mechanism to orient the communication direction of the transmitter towards the communication target.

The transmitting device of this embodiment rotates the rotation mechanism while the solenoid coil of the holding mechanism in which the transmitter that transmits a spatial light signal toward the communication target is placed is energized, thereby directing the transmission direction of the transmitter toward the communication target. According to this embodiment, the transmission direction of the transmitter can be adjusted to any direction within the rotation plane of the rotation mechanism. In other words, according to this embodiment, the position of the transmitter can be adjusted to correspond to any direction along the same plane.

In one aspect of this embodiment, the transmitting device is provided with a position detector that detects the position of the transmitter (communication device). The control unit aligns the communication direction of the transmitter with the communication target based on the position of the transmitter detected by the position detector. According to this aspect, the position of the transmitter can be adjusted based on the position of the transmitter detected by the position detector. Therefore, according to this aspect, the position of the transmitter can be accurately adjusted to match the position of the communication target.

Fourth Embodiment
Next, a communication device according to a fourth embodiment will be described with reference to the drawings. The communication device of this embodiment is a combination of the receiving device of the first and second embodiments and the transmitting device of the third embodiment. In the following, the description of the same parts as those of the first to third embodiments may be omitted.

(composition)
36 is a conceptual diagram showing an example of the configuration of the communication device 4 according to this embodiment. The communication device 4 includes a ball lens 40, a light source 41, a spatial light modulator 42, a light-sending mirror 43, a holding mechanism 47A, a holding mechanism 47B, a rotation mechanism 48, and a control unit 49. The holding mechanism 47A, the holding mechanism 47B, the rotation mechanism 48, and the control unit 49 constitute a position adjustment device. The holding mechanism 47A is used to adjust the position of the support 422 of the receiver. The holding mechanism 47B is used to adjust the position of the transmitter (light-sending mirror 43). The housing of the communication device 4 is composed of a cover (not shown), a base 410, and a cylinder 495. The base 410 and the cylinder 495 are circular in plan view.

The communication device 4 also includes a first relay mirror 451 and a second relay mirror 462 for forming an optical path between the spatial light modulator 42 and the light-transmitting mirror 43. In FIG. 36, the upper portion of the ball lens 40 and the upper portion of the communication device 4 including the light-receiving device that constitutes the receiver are omitted. FIG. 36 is a cross-sectional view of the communication device 4 as seen from a side perspective. The communication device 4 is stored inside a housing in which a window W for transmitting a spatial light signal is formed. FIG. 36 is conceptual and does not accurately represent the shape of each component or the positional relationship between the components.

Ball lens 40 has the same configuration as ball lens 10 of the first embodiment. Ball lens 40 is a spherical lens. Ball lens 40 focuses the incident spatial optical signal. Light (also called optical signal) derived from the spatial optical signal focused by ball lens 40 is focused toward the focusing area of ball lens 40. Ball lens 40 is supported by ball lens receiver 411, which has the shape of an upside-down spherical crown. It is placed on the top of support column 412. A through hole is formed inside support column 412 along the vertical direction. Light source 41 is placed in the through hole inside support column 412. A disk 414 is placed at the lower end of support column 412. An opening is formed in the center of disk 414 to match the through hole of support column 412.

Rotating plates 413A and 413B are arranged on the sides of the support post 412. Rotating plates 413A and 413B rotate in a horizontal plane with the support post 412 as the central axis. Rotating plate 413A is used to change the position of the receiver post 422. Rotating plate 413B is used to change the position of the transmitter (light-transmitting mirror 43). Rotating plate 413A is arranged above rotating plate 413B.

A rotation holding member 475A is installed on the side of the rotating plate 413A. The rotation holding member 475A is arranged in a ring shape to match the side of the rotating plate 413A, with the holding surface facing outward. A fixing holding member 476A is arranged on the inner surface of the cylindrical body 495 in a portion facing the rotation holding member 475A. The fixing holding member 476A is arranged in a ring shape to match the inner surface of the cylindrical body 495, with the holding surface facing inward.

A rotation holding member 475B is installed on the side of the rotating plate 413B. The rotation holding member 475B is arranged in a ring shape to match the side of the rotating plate 413B, with the holding surface facing outward. A fixed holding member 476B is arranged on the inner surface of the cylindrical body 495 in a portion facing the rotation holding member 475B. The fixed holding member 476B is arranged in a ring shape to match the inner surface of the cylindrical body 495, with the holding surface facing inward.

Circular support plate 415 is disposed between rotating plate 413A and rotating plate 413B. Circular support plate 415 is a disk with openings where support pillar 412 and rotating mechanism 48 are disposed. The receiving function is configured above circular support plate 415. The transmitting function is configured below circular support plate 415. In addition, a structure (track structure 490) for moving the receiver and transmitter is installed on circular support plate 415.

FIG. 37 is a conceptual diagram for explaining the track structure 490. The track structure 490 has an upper track 491 and a lower track 493. The upper track 491 is disposed on the upper surface of the circular support plate 415. The upper track 491 is composed of a pair of annular tracks formed concentrically around the support pillar 412. An annular recess is formed on the upper surface of the upper track 491. The lower end portion of a support leg 492 disposed on the lower surface of the holding rod 433A that holds the holding mechanism 47A is fitted into the annular recess formed on the upper surface of the upper track 491. The support leg 492 slides along the annular recess formed on the upper surface of the upper track 491 in response to the movement of the holding mechanism 47A.

The lower track 493 is disposed on the underside of the circular support plate 415. The lower track 493 is a hollow suspension structure formed in a ring shape around the support post 412. A pair of annular notches is formed on the underside of the lower track 493. The upper end portion of a suspension post 494, which is disposed on the upper surface of the retaining rod 433B that retains the retaining mechanism 47B, is fitted into the annular notches formed on the underside of the lower track 493. The suspension post 494 slides along the annular notches formed on the underside of the lower track 493 in response to the movement of the retaining mechanism 47B.

A holding mechanism 47A is disposed between the rotating holding member 475A and the fixed holding member 476A. The holding mechanism 47A has a solenoid 470A, a first fixed end 471A, a second fixed end 472A, a movable core 473A, and a spring 474A. The solenoid 470A, the first fixed end 471A, the second fixed end 472A, the movable core 473A, and the spring 474A have the same configuration as the corresponding configuration in the first embodiment. A coil (not shown) is disposed inside the solenoid 470A. The movable core 473A is inserted inside the coil. The solenoid 470A is disposed sideways so as to penetrate the holding rod 433A along the radial direction of the base 410. In response to the passage of electricity through the coil, the movable core 473A inside the solenoid 470A moves along the radial direction of a circle centered on the support pillar 412. A first fixed end 471A is provided at a first end of the movable core 473A. The first fixed end 471A has a shape with a plurality of cone-shaped protrusions protruding therefrom. A rotation holding member 475A is provided at the side of the first fixed end 471A. In this embodiment, when the coil is energized, the movable core 473A moves toward the outer periphery of the base 410. When the coil is energized, the first fixed end 471A is temporarily held by the rotation holding member 475A. A second fixed end 472A is provided at a second end of the movable core 473A. The second fixed end 472A has a shape with a plurality of cone-shaped protrusions protruding therefrom. A fixing holding member 476A is provided at the side of the second fixed end 472A. When the coil is not energized, the second fixed end 472A is held by the fixing holding member 476A. A spring 474A is disposed around the movable core 473A in a portion exposed to the outside between the solenoid 470A and the second fixed end 472A. The spring 474A is a helical coil spring.

The lower end of the receiver support 422 is connected to the upper end of the retaining rod 433A through which the solenoid 470A passes. A pair of support legs 492 are attached to the lower end of the retaining rod 433A. The spacing between the pair of support legs 492 is the same as the spacing between the annular tracks that make up the upper track 491 of the track structure 490. The lower end portions of the pair of support legs 492 are fitted into grooves on the upper surface of the upper track 491. The retaining rod 433A moves along the upper track 491. As the retaining rod 433A moves along the upper track 491, the receiver located at the upper end of the retaining rod 433A moves, and the orientation of the light receiving surface of the receiver is changed.

A holding mechanism 47B is disposed between the rotating holding member 475B and the fixed holding member 476B. The holding mechanism 47B has a solenoid 470B, a first fixed end 471B, a second fixed end 472B, a movable core 473B, and a spring 474B. The solenoid 470B, the first fixed end 471B, the second fixed end 472B, the movable core 473B, and the spring 474B have the same configuration as the corresponding configuration in the first embodiment. A coil (not shown) is disposed inside the solenoid 470B. The movable core 473B is inserted inside the coil. The solenoid 470B is disposed sideways so as to penetrate the holding rod 433B along the radial direction of the base 410. In response to the passage of electricity through the coil, the movable core 473B inside the solenoid 470B moves along the radial direction of a circle centered on the support pillar 412. A first fixed end 471B is provided at a first end of the movable core 473B. The first fixed end 471B has a shape with a plurality of cone-shaped protrusions protruding therefrom. A rotation holding member 475B is provided on the side of the first fixed end 471B. In this embodiment, when the coil is energized, the movable core 473B moves toward the outer periphery of the base 410. When the coil is energized, the first fixed end 471B is temporarily held by the rotation holding member 475B. A second fixed end 472B is provided at a second end of the movable core 473B. The second fixed end 472B has a shape with a plurality of cone-shaped protrusions protruding therefrom. A fixing holding member 476B is provided on the side of the second fixed end 472B. When the coil is not energized, the second fixed end 472B is held by the fixing holding member 476B. A spring 474B is disposed around the movable core 473B in a portion exposed to the outside between the solenoid 470B and the second fixed end 472B. The spring 474B is a helical coil spring.

The upper end of the suspension pole 431 is connected to the lower end of the holding pole 433B through which the solenoid 470B passes in order to suspend the light-transmitting mirror 43 of the transmitter. The light-transmitting mirror 43 is suspended by the suspension pole 431 below the holding pole 433B on which the holding mechanism 47B is disposed. The light-transmitting mirror 43 and the suspension pole 431 constitute the transmitter. The transmitter and the holding mechanism 47B are paired. The communication device 4 includes multiple pairs of transmitters and holding mechanisms 47B. A pair of suspension poles 494 are installed at the upper end of the holding pole 433B. The distance between the pair of suspension poles 494 is the same as the distance between the annular notches that form the lower track 493 of the track structure 490. The upper end portions of the pair of suspension poles 494 are fitted into the interior of the lower track 493 via the notches in the lower surface of the lower track 493. The holding pole 433B moves along the lower track 493. As the holding rod 433B moves along the lower track 493, the light-transmitting mirror 43 of the transmitter located at the lower end of the holding rod 433B moves, changing the light-transmitting direction of the spatial light signal (projected light 403).

The rotation mechanism 48 has a motor 481, rotating shaft 482A, rotating shaft 482B, tire 483A, tire 483B, and a gear box 484. The rotation of the motor shaft of the motor 481 is transmitted to rotating shaft 482A and rotating shaft 482B via a number of gears arranged inside the gear box. Rotating shaft 482A and rotating shaft 482B are shafts that rotate in accordance with the rotation of the motor 481. Tire 483A is attached to rotating shaft 482A. Tire 483B is attached to rotating shaft 482B. Tire 483A and tire 483B have the same diameter. Tire 483A and tire 483B are made of an elastic material such as rubber. The side of tire 483A is arranged so as to contact the lower surface of rotating plate 413A. The side of tire 483B is arranged so as to contact the upper surface of rotating plate 413B. Tire 483A attached to rotating shaft 482A rotates in accordance with the rotation of rotating shaft 482A in response to the drive of motor 481 by a drive device (not shown). Tire 483B attached to rotating shaft 482B rotates in accordance with the rotation of rotating shaft 482B in response to the drive of motor 481 by the drive device. Tire 483A and tire 483B rotate at the same rotation speed in opposite directions in response to the drive of motor 481.

FIG. 38 is a conceptual diagram for explaining the movement of the rotation mechanism 48. FIG. 38 is a view of the tire 483A and tire 483B from a side perspective of the communication device 4. The outer circumferences of tires 483A and 483B are separated. Tires 483A and 483B rotate in opposite directions, and in response to the clockwise rotation of tire 483A, rotating plate 413A rotates toward the right on the paper in FIG. 38. In response to the counterclockwise rotation of tire 483B, rotating plate 413B rotates toward the right on the paper in FIG. 38. As a result, rotating plates 413A and 413B rotate in the same direction.

Figure 39 is a conceptual diagram showing an example of the relative positions of the receiver R and transmitter T included in the communication device 4. Figure 39 shows the relative positions of the receiver R and transmitter T at the time of shipment. The receiver R and transmitter T assigned to the same communication target are placed in symmetrical positions with the support pole 412 at the center. If placed in this manner at the time of shipment, the receiving direction of the receiver R and the transmitting direction of the transmitter T will coincide with the rotation of the tires 483A and 483B.

When the coil of solenoid 470A is energized, first fixed end 471A is held by rotation holding member 475A. When rotating plate 413A is rotated around support post 412 while first fixed end 471A is held by rotation holding member 475A, the position of holding mechanism 47A changes. In response to the change in position of holding mechanism 47A, the orientation of the light receiving surface of the light receiver that constitutes the receiver paired with that holding mechanism 47A changes.

When the coil of solenoid 470A is de-energized, the elastic force of spring 474A causes movable core 473A to move toward support post 412, and second fixed end 472A is held by fixing retaining member 476A. With second fixed end 472A held by fixing retaining member 476A, the transmitter in which holding mechanism 47A is installed does not move.

When the coil of the solenoid 470B is energized, the first fixed end 471B is held by the rotating holding member 475B. When the rotating plate 413B is rotated around the support post 412 while the first fixed end 471B is held by the rotating holding member 475B, the position of the holding mechanism 47B changes. In response to the change in the position of the holding mechanism 47B, the orientation of the reflective surface 430 of the light-transmitting mirror 43 that constitutes the transmitter paired with the holding mechanism 47B changes.

When the coil of the solenoid 470B is de-energized, the movable core 473B moves toward the support column 412 in response to the elastic force of the spring 474B, and the second fixed end 472B is held by the fixing holding member 476B. With the second fixed end 472B held by the fixing holding member 476B, the transmitter on which the holding mechanism 47B is installed does not move.

The light source 41 has the same configuration as the light source 31 of the third embodiment. The light source 41 emits illumination light 401. The light source 41 is arranged inside the through hole of the support column 412 with the emission surface facing downward. The emission surface of the light source 41 is directed through the through hole formed in the support column 412 to the modulation section 420 of the spatial light modulator 42 arranged below. The illumination light 401 emitted from the light source 41 passes through the through hole formed in the support column 412 and is irradiated to the modulation section 420 of the spatial light modulator 42. The light source 41 may be arranged below the support column 412.

The spatial light modulator 42 has the same configuration as the spatial light modulator 32 of the third embodiment. The spatial light modulator 42 is a phase modulation type spatial light modulator. The spatial light modulator 42 has a modulation section 420. The spatial light modulator 42 is disposed below the light source 41. The spatial light modulator 42 is disposed at a position where modulated light 402 obtained by modulating the illumination light 401 emitted from the light source 41 is reflected toward the reflecting surface 4510 of the first relay mirror 451. The traveling direction of the modulated light 402 is controlled according to the pattern (phase image) set in the modulation section 420.

A plurality of modulation areas are set in the modulation section 420 of the spatial light modulator 42. In each of the plurality of modulation areas, a pattern (also called a phase image) corresponding to the image displayed by the projected light 403 is set according to the control of the communication control device. A pattern (phase image) is set in each of the plurality of modulation areas. The illumination light 401 irradiated to each of the plurality of modulation areas is modulated according to the pattern (phase image) set in the modulation area. The modulated light 402 modulated in each of the plurality of modulation areas proceeds toward the reflecting surface 4510 of the first relay mirror 451.

The first relay mirror 451 is disposed on the underside of the disk 414. Figure 40 is a conceptual diagram of the underside of the disk 414 on which the first relay mirror 451 is disposed, viewed from below. The first relay mirror 451 is an annular mirror formed in a circular shape centered on the support column 412. The reflecting surface 4510 of the first relay mirror 451 faces downward. The modulated light 402 modulated by the modulation section 420 of the spatial light modulator 42 is irradiated onto the reflecting surface 4510 of the first relay mirror 451. The modulated light 402 irradiated onto the reflecting surface 4510 of the first relay mirror 451 is reflected toward the reflecting surface 4520 of the second relay mirror 452.

The second relay mirror 452 is disposed on the upper surface of the base 410. FIG. 41 is a conceptual diagram of the upper surface of the base 410 on which the second relay mirror 452 is disposed, viewed from above. The second relay mirror 452 is an annular mirror formed in a circular ring shape centered on the central axis of the base 410 on which the spatial light modulator 42 is disposed. The diameter of the second relay mirror 452 is larger than the diameter of the first relay mirror 451. The reflecting surface 4520 of the second relay mirror 452 is directed upward. The modulated light 402 reflected by the reflecting surface 4510 of the first relay mirror 451 is irradiated onto the reflecting surface 4520 of the second relay mirror 452. The modulated light 402 irradiated onto the reflecting surface 4520 of the second relay mirror 452 is reflected toward the reflecting surface 430 of the light-sending mirror 43.

The light-transmitting mirror 43 has the same configuration as the light-transmitting mirror 33 of the third embodiment. The light-transmitting mirror 43 is a reflector having a reflective surface 430. The light-transmitting mirror 43 is disposed after the second relay mirror 452. The light-transmitting mirror 43 is disposed at the lower end of the suspension pole 431. The light-transmitting mirror 43 moves in accordance with the movement of the holding rod 433B. The position of the light-transmitting mirror 43 is changed according to the control of the control unit 49. In response to the detection of a spatial optical signal from the communication target, the position of the light-transmitting mirror 43 is changed so that the reflective surface 430 faces the direction from which the spatial optical signal comes.

The light-sending mirror 43 is arranged with its reflecting surface 430 facing obliquely toward the reflecting surface 4520 of the second relay mirror 452. The light-sending mirror 43 is arranged in the optical path of the modulated light 402 relayed by the first relay mirror 451 and the second relay mirror 452. The modulated light 402 reflected by the reflecting surface 4520 of the second relay mirror 452 is irradiated onto the reflecting surface 430 of the light-sending mirror 43. The light reflected by the reflecting surface 430 (projected light 403) is projected as a spatial light signal. The projected light 403 is projected in a direction according to the irradiation position of the modulated light 302 on the reflecting surface 430 of the light-sending mirror 43. For example, a lens (not shown) may be arranged after the light-sending mirror 43 to limit the spread of the projected light 403.

The reflecting surface 430 of the light-transmitting mirror 43 can be oriented in any direction in the horizontal plane depending on the position of the holding rod 433B that supports the light-transmitting mirror 43. Therefore, the communication device 4 can project the projection light 403 in 360-degree directions in the horizontal plane by controlling the pattern (phase image) set in the modulation section 420 of the spatial light modulator 42. In addition, the communication device 4 can transmit the projection light 403 (spatial light signal) simultaneously to communication targets located in multiple directions by associating multiple modulation areas set in the modulation section 420 with different directions.

The control unit 49 includes a drive function for driving the holding mechanism 47A, the holding mechanism 47B, and the rotation mechanism 48. The control unit 49 also includes a receiving function for processing the spatial light signal received by the receiver. The control unit 49 also includes a transmitting function for transmitting the spatial light signal toward the communication target. For example, the control unit 49 is realized by a microcomputer having a processor and a memory.

In the stage of establishing communication with a communication target, the control unit 49 detects the communication target according to the light received by at least one of the multiple receivers. The control unit 49 identifies the direction of the detected communication target according to the light reception state by the receiver. The control unit 49 selects a receiver to be used for communication with the communication target in the identified direction. The control unit 49 energizes the solenoid 470A of the holding mechanism 47A paired with the selected receiver. In this state, the first fixed end 471A of the holding mechanism 47A is held by the rotating holding member 475A. The selected receiver is paired with a transmitter arranged in a position symmetrical with respect to the central axis of the support column 412. The control unit 49 energizes the solenoid 470B of the holding mechanism 47B of the transmitter paired with the selected receiver. In this state, the first fixed end 471B of the holding mechanism 47B is held by the rotating holding member 475B.

The control unit 49 drives the rotation mechanism 48 to orient the light receiving surface of the light receiver of the selected receiver and the reflective surface 430 of the light transmitting mirror 43 of the transmitter paired with that receiver toward the communication target. The control unit 49 adjusts the position of the light transmitting mirror 43 according to a change from the preset initial position of the light transmitting mirror 43. When the light receiving surface of the light receiver and the reflective surface 430 of the light transmitting mirror 43 are directed toward the communication target, the control unit 49 releases the power supply to the solenoid 470A of the holding mechanism 47A paired with the selected receiver. When the power supply is released, the second fixed end 472A of the holding mechanism 47A is held by the fixing holding member 476A. The control unit 49 also releases the power supply to the solenoid 470B included in the holding mechanism 47B of the transmitter paired with the receiver. When the current is removed, the second fixed end 472B of the holding mechanism 47B is held by the fixing holding member 476B. At this stage, the environment for spatial optical communication between the communication device 4 and the communication target is prepared.

The control unit 49 receives a spatial optical signal from the communication target using the receiver's photodetector. The control unit 49 acquires the signal output from the photodetector of the photodetector. The control unit 49 amplifies the signal from the photodetector. Details of the signal processing by the control unit 49 will not be explained here. The control unit 49 decodes the amplified signal. The signal decoded by the control unit 49 is used for any purpose. There are no particular limitations on the use of the signal decoded by the control unit 49.

The control unit 49 also controls the light source 41 and the spatial light modulator 42 to irradiate the modulated light 402 that forms a spatial light signal onto the reflecting surface 430 of the light-sending mirror 43 via the first relay mirror 451 and the second relay mirror 462. The projected light 403 reflected by the reflecting surface 430 of the light-sending mirror 43 is transmitted as a spatial light signal toward the communication target. There are no particular limitations on the modulation method of the spatial light signal, etc.

According to the method of this embodiment, the receiver and transmitter can be adjusted at the same time so that they are directed toward the same communication target. Note that the timing of the adjustment of the receiver and transmitter to the same communication target does not have to be completely simultaneous, and may be offset.

[Modification 5]
Fig. 42 is a conceptual diagram showing an example of the configuration of a modified example 5 (communication device 4-5) related to the communication device 4 of this embodiment. Fig. 42 is a cross-sectional view of the communication device 4-5 seen from a side perspective. The communication device 4-5 differs from the communication device 4 (Fig. 36) in that it includes a pillar avoidance mirror 44 for transmitting a spatial optical signal while avoiding the pillar of the cylinder 495, similar to the transmission device 3-4 of the modified example 4 according to the third embodiment.

Similar to the fourth modification of the third embodiment, the cylindrical body 495 of the communication device 4-5 has a pillar (see FIG. 34). If the communication target is located in the direction of the pillar, the light reflected by the light-transmitting mirror 43 is blocked by the pillar. For this reason, the communication device 4-5 is configured with a pillar avoidance mirror 44 for avoiding the pillar. The pillar avoidance mirror 34 is suspended below the disk 414 by a suspension pole 441. The pillar avoidance mirror 44 is installed below the light-transmitting mirror 43. Unlike the light-transmitting mirror 43, the position of the pillar avoidance mirror 44 is fixed. Two pillar avoidance mirrors 44 are placed on each pillar so that spatial optical signals can be transmitted from both sides of the pillar. The reflective surface 440 of the pillar avoidance mirror 44 faces the outside of the cylindrical body 495.

Similar to the fourth modified example (FIG. 33) of the third embodiment, in a position that is not blocked by a pillar, the projected light 403 reflected by the reflecting surface 430 of the light-transmitting mirror 43 is transmitted as a spatial light signal. In a position that is blocked by a pillar, the projected light 404 reflected by the reflecting surface 440 of the pillar avoidance mirror 44 is transmitted as a spatial light signal.

According to this modified example, spatial optical signals can be transmitted in directions where there are pillars as well as in directions where there are no pillars. In practice, it is necessary to install wiring connecting the receiving function above the communication device 4 with the transmitting function below. Also, in order to ensure the strength of the housing of the communication device 4, a structure is required to reinforce part of the window W. According to this modified example, spatial optical signals can be transmitted in any direction along the horizontal plane while ensuring the placement and strength of the wiring.

[Application example]
Next, application examples of this embodiment will be described with reference to the drawings. In the following application example, a plurality of communication devices 4 transmit and receive spatial optical signals. FIG. 43 is a conceptual diagram for explaining this application. In this application example, an example (communication system) of a communication network in which a plurality of communication devices 4 are arranged on the tops (pole space) of poles such as utility poles and street lights arranged in a city is given.

There are few obstacles in the space above the pillar. Therefore, the space above the pillar is suitable for installing the communication device 4. Furthermore, if the communication devices 4 are installed at approximately the same height, the direction of arrival of the spatial light signal is limited to the horizontal direction. A pair of communication devices 4 that transmit and receive spatial light signals is placed in a position where at least one of the communication devices 4 can receive the spatial light signal transmitted from the other communication device 4. A pair of communication devices 4 may be placed so that they transmit and receive spatial light signals to each other. When a communication network for spatial light signals is made up of multiple communication devices 4, a communication device 4 located in the middle may be configured to relay the spatial light signal transmitted from the other communication devices 4 to another communication device 4.

According to this application example, optical space communication using spatial optical signals becomes possible between multiple communication devices 4 arranged in the space above the pole. For example, in addition to optical space communication between the communication devices 4, wireless communication using radio waves may be performed between the communication devices 4 and wireless devices or base stations installed in automobiles, houses, etc. For example, the communication devices 4 may be connected to the Internet via a communication cable or the like installed on the pole.

As described above, the communication device of this embodiment includes a position adjustment device according to any one of the first to third embodiments, a receiving device that receives a spatial light signal, and a transmitting device that transmits a spatial light signal. The receiving device has a ball lens and at least one receiver. The ball lens is a spherical lens. The receiver is arranged to move in accordance with the movement of the associated holding mechanism. The receiver includes a receiver in which at least one receiving element is arranged. The receiver is arranged with the light receiving portion of the receiver facing the light collecting area of the ball lens. The transmitting device has a light source, a spatial light modulator, and at least one transmitter. The light source includes at least one emitter. The spatial light modulator has a modulation portion that modulates the illumination light emitted from the light source. The transmitter is arranged to move in accordance with the movement of the associated holding mechanism. The transmitter includes a light transmitting mirror. The light transmitting mirror has a reflective surface that is irradiated with modulated light modulated by the modulation portion and reflects the modulated light in any direction along a horizontal plane.

The communication device of this embodiment rotates the rotation mechanism while the coil of the solenoid of the holding mechanism in which the receiver that receives spatial optical signals from the communication target is placed is energized, thereby orienting the receiving direction of the receiver towards the communication target. Also, the communication device of this embodiment rotates the rotation mechanism while the coil of the solenoid of the holding mechanism in which the transmitter that transmits spatial optical signals towards the communication target is placed is energized, thereby orienting the transmitting direction of the transmitter towards the communication target. According to this embodiment, the receiving direction of the receiver and the transmitting direction of the transmitter can be adjusted to any direction within the rotation plane of the rotation mechanism. In other words, according to this embodiment, the positions of the receiver and transmitter can be adjusted to correspond to any direction along the same plane.

In one aspect of this embodiment, the transmitter includes a first relay mirror and a second relay mirror. The first relay mirror is formed in an annular shape centered on the optical axis of the illumination light emitted from the light source. The first relay mirror is arranged above the spatial light modulator with its reflective surface facing downward. The second relay mirror is formed in an annular shape centered on the optical axis of the illumination light. The second relay mirror is arranged around the spatial light modulator with its reflective surface facing upward. The first relay mirror is arranged in a position where it reflects modulated light modulated by the modulation section of the spatial light modulator toward the reflective surface of the first relay mirror. The second relay mirror is arranged in a position where it reflects modulated light reflected by the reflective surface of the first relay mirror toward a position where the reflective surface of the light-transmitting mirror included in at least one transmitter is located. According to this aspect, the height of the communication device can be reduced by folding back the optical path of the modulated light using the first relay mirror and the second relay mirror.

In one aspect of this embodiment, the position adjustment device cooperatively controls a pair of a receiver and a transmitter associated with the same communication target so that the receiving direction of the receiver and the transmitting direction of the transmitter are the same. According to this aspect, by cooperatively controlling the pair of a receiver and a transmitter, it is possible to efficiently establish communication with the communication target. For example, if the pair of a receiver and a transmitter are positioned diagonally when the communication device is shipped, it is possible to more efficiently establish communication with the communication target in the field.

A communication system according to one aspect of this embodiment includes a plurality of the above-described communication devices. In the communication system, the plurality of communication devices are arranged to transmit and receive spatial optical signals to and from each other. According to this aspect, a communication network that transmits and receives spatial optical signals can be realized.

Fifth Embodiment
Next, a position adjustment device according to a fifth embodiment will be described with reference to the drawings. The position adjustment device according to this embodiment has a simplified configuration of the position adjustment device according to the first to fourth embodiments. Figure 44 is a conceptual diagram showing an example of the configuration of the position adjustment device 5 according to this embodiment.

The position adjustment device 5 includes a holding mechanism 57, a rotation mechanism 58, and a control unit 59. The holding mechanism 57 is disposed in each of the multiple communication devices. The holding mechanism 57 has a solenoid in which a movable core including a first fixed end facing the rotation holding member and a second fixed end facing the fixed holding member is inserted into a coil. When the coil is energized, the movable core moves toward the rotation holding member, and the first fixed end is held by the rotation holding member. On the other hand, when the coil is de-energized, the movable core moves toward the fixed holding member and moves away from the rotation holding member. A ring-shaped rotation holding member is installed in the rotation mechanism 58. The control unit 59 controls the coil of the solenoid of the holding mechanism in which the communication device used for communication with the communication target is disposed, and rotates the rotation mechanism to orient the communication direction of the communication device toward the communication target.

The position adjustment device of this embodiment rotates the rotation mechanism while the coil of the solenoid of the holding mechanism in which the communicator used for communication with the communication target is placed is energized, thereby directing the communication direction of the communicator towards the communication target. According to this embodiment, the communication direction of the communicator can be adjusted to face any direction within the rotation plane of the rotation mechanism. In other words, according to this embodiment, the position of the communicator can be adjusted to correspond to any direction along the same plane.

(Hardware)
Next, a hardware configuration for executing control and processing according to each embodiment of the present disclosure will be described with reference to the drawings. Here, an information processing device 90 (computer) in FIG. 45 is given as an example of such a hardware configuration. The information processing device 90 in FIG. 45 is an example of a configuration for executing control and processing according to each embodiment, and does not limit the scope of the present disclosure.

As shown in FIG. 45, the information processing device 90 includes a processor 91, a main memory device 92, an auxiliary memory device 93, an input/output interface 95, and a communication interface 96. In FIG. 45, the interface is abbreviated as I/F (Interface). The processor 91, the main memory device 92, the auxiliary memory device 93, the input/output interface 95, and the communication interface 96 are connected to each other via a bus 98 so as to be able to communicate data with each other. In addition, the processor 91, the main memory device 92, the auxiliary memory device 93, and the input/output interface 95 are connected to a network such as the Internet or an intranet via the communication interface 96.

The processor 91 expands a program (instructions) stored in the auxiliary storage device 93 or the like into the main storage device 92. For example, the program is a software program for executing the control and processing of each embodiment. The processor 91 executes the program expanded into the main storage device 92. The processor 91 executes the program to execute the control and processing of each embodiment.

The main memory 92 has an area in which programs are expanded. Programs stored in the auxiliary memory 93, etc. are expanded in the main memory 92 by the processor 91. The main memory 92 is realized by a volatile memory such as a DRAM (Dynamic Random Access Memory). In addition, a non-volatile memory such as an MRAM (Magneto-resistive Random Access Memory) may be configured/added to the main memory 92.

The auxiliary storage device 93 stores various data such as programs. The auxiliary storage device 93 is realized by a local disk such as a hard disk or flash memory. Note that it is also possible to omit the auxiliary storage device 93 by configuring the main storage device 92 to store various data.

The input/output interface 95 is an interface for connecting the information processing device 90 to peripheral devices based on standards and specifications. The communication interface 96 is an interface for connecting to external systems and devices via a network such as the Internet or an intranet based on standards and specifications. The input/output interface 95 and the communication interface 96 may be a common interface for connecting to external devices.

If necessary, input devices such as a keyboard, mouse, or touch panel may be connected to the information processing device 90. These input devices are used to input information and settings. When a touch panel is used as the input device, a screen having the function of a touch panel becomes the interface. The processor 91 and the input devices are connected via an input/output interface 95.

The information processing device 90 may be equipped with a display device for displaying information. If a display device is equipped, the information processing device 90 is equipped with a display control device (not shown) for controlling the display of the display device. The information processing device 90 and the display device are connected via an input/output interface 95.

The information processing device 90 may be equipped with a drive device. The drive device acts as an intermediary between the processor 91 and a recording medium (program recording medium) to read data and programs stored on the recording medium and to write the processing results of the information processing device 90 to the recording medium. The information processing device 90 and the drive device are connected via an input/output interface 95.

The above is an example of a hardware configuration for enabling the control and processing according to each embodiment of the present invention. The hardware configuration in FIG. 45 is an example of a hardware configuration for executing the control and processing according to each embodiment, and does not limit the scope of the present invention. Programs that cause a computer to execute the control and processing according to each embodiment are also included in the scope of the present invention.

The scope of the present invention also includes a program recording medium on which the program according to each embodiment is recorded. The recording medium can be realized, for example, as an optical recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc). The recording medium may also be realized as a semiconductor recording medium such as a USB (Universal Serial Bus) memory or an SD (Secure Digital) card. The recording medium may also be realized as a magnetic recording medium such as a flexible disk, or other recording medium. When the program executed by the processor is recorded on a recording medium, the recording medium corresponds to a program recording medium.

The components of each embodiment may be combined in any manner. The components of each embodiment may be realized by software. The components of each embodiment may be realized by circuitry.

The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

REFERENCE SIGNS LIST 1, 2 Receiving device 3 Transmitting device 4 Communication device 5 Position adjustment device 10, 20, 40 Ball lens 12, 22 Receiver 17, 27, 37, 47, 57 Holding mechanism 18, 28, 38, 48, 58 Rotation mechanism 19, 29, 39, 49, 59 Control unit 31, 41 Light source 32, 42 Spatial light modulator 33, 43 Light-transmitting mirror 34, 44 Pillar avoidance mirror 35 Direction detection receiver 110, 210, 310, 410 Base 111, 211, 411 Ball lens holder 112, 212, 312, 412 Support pillar 113, 213 Cylindrical pillar 115, 315 First bearing 117 Annular pillar 118, 318 Second bearing 119, 219 Circuit area 121, 221 Light receiver 122, 222, 422 Support 123, 333, 433A, 433B Holding rod 125, 335 First end 126, 336 Second end 170, 270, 370, 470A, 470B Solenoid 171, 271, 371, 47 1A, 471B First fixed end 172, 272, 372, 472A, 472B Second fixed end 173, 273, 373, 473A, 473B Movable core 174, 274, 374, 474A, 474B Spring 175, 275, 375, 475A, 475B Rotation holding member 176, 276, 376, 476A, 476B Fixing holding member 181, 281, 381, 481 Motor 182, 282, 382 Rotating shaft 183, 283, 383, 483A, 483B Tire 184, 284 Annular track 185, 285 Rotating table 225 First annular track 226 Second annular track 278 First support 279 Second support 300 Cover 380 Annular body 390 Cylinder 316 Bearing 331 Suspension column 385 Rotating plate 413A, 413B Rotating plate 414 Circular plate 415 Circular support plate 451 First relay mirror 452 Second relay mirror 482A, 482B Rotating shaft 484 Gear box 490 Track structure 491 Upper track 492 Support leg 493 Lower track

Claims (10)

A rotation mechanism having an annular rotation holding member;
a holding mechanism that is disposed in each of the plurality of communication devices, the holding mechanism having a solenoid in which a movable core including a first fixed end facing the rotation holding member and a second fixed end facing the fixed holding member is inserted into a coil, the movable core moves toward the rotation holding member in response to energization of the coil, and the first fixed end is held by the rotation holding member, and the movable core moves toward the fixed holding member in response to de-energization of the coil, and moves away from the rotation holding member;
and a control means for passing current through the coil of the solenoid of the holding mechanism in which the communication device used for communication with a communication target is placed, and rotating the rotation mechanism to control the communication direction of the communication device to face the communication target. The first fixed end is
A shape having a plurality of protrusions protruding therefrom,
The rotation holding member is
The position adjustment device according to claim 1 , wherein the first fixed end has a structure for being temporarily held. The position adjustment device according to claim 1, in which the movable core inserted into the coil of the solenoid of the holding mechanism is arranged to be movable along the vertical direction, the first fixed end faces upward, and the second fixed end faces downward, and the movable core moves upward in response to the passage of electricity through the coil, and the first fixed end is held by the rotating holding member arranged above. The position adjustment device according to claim 1, in which the movable core inserted into the coil of the solenoid of the holding mechanism is arranged to be movable along the horizontal direction, the first fixed end is oriented in the circumferential direction of the rotating mechanism, the second fixed end is oriented in the direction of the rotation axis of the rotating mechanism, the movable core moves in the direction of the rotation axis of the rotating mechanism in response to the passage of current through the coil, and the first fixed end is held by the rotation holding member arranged in the direction of the rotation axis of the rotating mechanism. A position detector is provided to detect the position of the communication device,
The control means
The position adjustment device according to claim 1 , wherein the communication direction of the communication device is adjusted to the communication target based on the position of the communication device detected by the position detector. A position adjustment device according to any one of claims 1 to 5,
A ball lens and
At least one receiver having at least one light receiving element and corresponding to the communication device;
The receiver includes:
A receiving device arranged to move circularly in the light-collecting region of the ball lens in accordance with the movement of a holding mechanism of the associated position adjustment device. A position adjustment device according to any one of claims 1 to 5,
a light source including at least one emitter;
a spatial light modulator having a modulation unit that modulates the illumination light emitted from the light source;
and at least one transmitter corresponding to the communication device, the transmitter including a light-transmitting mirror having a reflecting surface that is irradiated with modulated light modulated by the modulation unit and that reflects the modulated light in any direction along a horizontal plane, the transmitter comprising:
A transmitting device arranged to move in a circular shape about the optical axis of the illumination light in accordance with the movement of a holding mechanism of the associated position adjustment device. A position adjustment device according to any one of claims 1 to 5,
A receiving device for receiving a spatial light signal;
a transmitting device for transmitting a spatial light signal;
The receiving device includes:
A ball lens and
At least one receiver including a light receiver arranged to move in accordance with the movement of the associated holding mechanism and having at least one receiving element arranged thereon, the at least one receiver arranged with a light receiving portion of the light receiver facing a light collecting region of the ball lens;
The transmitting device includes:
a light source including at least one emitter;
a spatial light modulator having a modulation unit that modulates the illumination light emitted from the light source;
and at least one transmitter arranged to move in response to movement of the associated holding mechanism, which transmitter is irradiated with modulated light modulated by the modulation section and includes a light-transmitting mirror having a reflective surface that reflects the modulated light in any direction along a horizontal plane. The transmitter includes:
a first relay mirror that is formed in an annular shape centered on the optical axis of the illumination light emitted from the light source and that is disposed above the spatial light modulator with a reflecting surface facing downward;
a second relay mirror that is formed in an annular shape around the optical axis of the illumination light and is disposed around the spatial light modulator with a reflecting surface facing upward;
The first relay mirror is
The light modulated by the modulation unit of the spatial light modulator is disposed at a position where the light is reflected toward a reflection surface of the first relay mirror.
The second relay mirror is
9. The communication device according to claim 8, wherein the communication device is disposed at a position where the modulated light reflected by the reflecting surface of the first relay mirror is reflected toward a reflecting surface of the light sending mirror included in at least one of the transmitters. A communication device according to claim 9,
A plurality of the communication devices,
A communications system arranged to transmit and receive spatial optical signals to and from each other.

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