JP2018153536A - Ophthalmic equipment - Google Patents

Abstract

The present invention provides a new technique for performing high-precision alignment between an optical system and an eye to be examined while avoiding contact. An ophthalmologic apparatus includes an optical system for acquiring data of an eye to be examined, a drive unit that relatively moves the optical system and the eye to be examined in the optical axis direction of the optical system, an optical system, and an eye to be examined. A distance specifying unit that repeatedly specifies the distance between the control unit and the control condition for the driving unit based on the distance sequentially specified by the distance specifying unit, and the driving unit is controlled based on the updated control condition Thus, a control unit that relatively moves the optical system and the eye to be examined is included. [Selection] Figure 1

Description

  The present invention relates to an ophthalmologic apparatus for acquiring data of an eye to be examined.

  The ophthalmologic apparatus includes an ophthalmologic measuring apparatus for measuring the characteristics of the eye to be examined and an ophthalmologic photographing apparatus for obtaining an image of the eye to be examined.

  Examples of ophthalmic measuring devices include an ocular refraction examination device (refractometer, keratometer) that measures the refractive properties of the eye to be examined, a tonometer, a specular microscope that obtains the properties of the cornea (corneal thickness, cell distribution, etc.) There is a wavefront analyzer that obtains aberration information of an eye to be examined using a Hartmann-Shack sensor.

  As an example of an ophthalmologic photographing apparatus, an optical coherence tomography (Optical Coherence Tomography, OCT) is used to obtain a tomographic image, a fundus camera for photographing a fundus, or laser scanning using a confocal optical system. There is a scanning laser ophthalmoscope (SLO) that obtains an image of the fundus.

  In an ophthalmic examination using such an apparatus, the alignment (alignment) between the optical system and the eye to be examined is important from the viewpoint of the accuracy and accuracy of the examination. In general, the alignment includes an operation of aligning the optical axis of the optical system with the axis of the eye to be examined (XY alignment), and an operation of adjusting the distance between the eye to be examined and the optical system to a predetermined working distance (Z alignment). is there.

  In particular, an ophthalmologic apparatus that requires Z alignment is provided with a mechanism for avoiding contact between a measurement unit that houses an optical system and the eye to be examined, and avoids contact between the measurement unit and the eye to be examined. In this way, the drive unit that moves the measurement unit or the like is controlled.

  For example, Patent Literature 1 discloses an ophthalmologic apparatus including a safety stopper mechanism for avoiding contact between a gantry and an eye to be examined.

  For example, in Patent Document 2, by projecting index light onto the eye to be examined and detecting an index image based on the reflected light, the position of the apparatus body installed on the gantry is detected, and the apparatus body is inspected by the eye. In contrast, there is disclosed a method of stopping the movement of the gantry forward when it is determined that the vehicle has approached a predetermined distance or more.

  For example, Patent Document 3 discloses a method of projecting index light onto an eye to be examined, bending the reflected light in two directions with a prism lens, and detecting the light with a two-dimensional light receiving element, thereby providing a cornea and an optometry unit of the eye to be examined. Is calculated, and the movement of the optometry unit is stopped when the distance between the optometry unit and the eye to be examined is closer than the appropriate working distance.

JP 2013-220134 A Japanese Patent Laid-Open No. 01-274737 Japanese Patent Laid-Open No. 08-126609

  However, in the method disclosed in Patent Document 1, there is an individual difference in the position of the eye even if the subject fixes his face to the forehead, so it is necessary to set the position of the safety stopper for each subject. There is.

  In the methods disclosed in Patent Document 2 and Patent Document 3, the alignment state of the optical system with respect to the eye to be examined is specified by detecting the index image based on the reflected light of the index light projected on the eye to be examined. Therefore, if blinking of the eye to be examined or a change in line of sight occurs during the alignment, the alignment state cannot be specified. Thus, in the case of auto alignment, it is necessary to stop driving the optical system and wait until the index image is detected again. On the other hand, in the case of manual alignment, the optical system can be advanced by the operation of a user such as an examiner. Therefore, it is conceivable to provide a safety stopper mechanism as disclosed in Patent Document 1 or not to accept the operation of the examiner while the index image is not detected. Every time the movement stops, the operation becomes uncomfortable.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a new technique for performing high-precision alignment between an optical system and an eye to be examined while avoiding contact. It is in.

The first aspect of the ophthalmologic apparatus according to the embodiment includes an optical system for acquiring data of an eye to be examined, and a drive unit that relatively moves the optical system and the eye to be examined in the optical axis direction of the optical system. A distance specifying unit that repeatedly specifies a distance between the optical system and the eye to be examined, and a control condition for the driving unit is sequentially updated based on the distance sequentially specified by the distance specifying unit, and updated. And a control unit that moves the optical system and the eye to be examined relative to each other by controlling the driving unit based on the control condition.
In the second aspect of the ophthalmologic apparatus according to the embodiment, in the first aspect, the control unit is configured to prevent the optical system from approaching the eye to be examined more than a predetermined distance based on the distance. May be controlled.
In the third aspect of the ophthalmologic apparatus according to the embodiment, in the first aspect or the second aspect, the control unit is configured so that the optical system approaches the eye to be examined based on the sequentially specified distance. The movable distance may be obtained sequentially, and the drive unit may be controlled within the movable distance range in the direction.
In the fourth aspect of the ophthalmologic apparatus according to the embodiment, in the third aspect, the optical system includes an objective lens, and the control unit moves the distance obtained by subtracting the working distance of the objective lens from the distance. You may obtain | require as possible distance.
Further, a fifth aspect of the ophthalmologic apparatus according to the embodiment is any one of the first aspect to the fourth aspect, wherein two or more imaging units for simultaneously imaging the anterior eye part of the eye to be examined from different directions; A position specifying unit that specifies a three-dimensional position of the eye to be examined by analyzing two or more captured images obtained simultaneously by two or more imaging units, and the distance specifying unit includes the optical system and the optical system You may specify the distance between three-dimensional positions.
A sixth aspect of the ophthalmic apparatus according to the embodiment includes an operation unit according to any one of the first to fifth aspects, and the control unit controls the drive unit according to an operation using the operation unit. The optical system and the eye to be examined may be moved relative to each other by control.
In addition, it is possible to combine arbitrarily the structure which concerns on the above-mentioned several aspect.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the new technique for performing highly accurate position alignment with an optical system and a to-be-examined eye, avoiding a contact.

It is a schematic diagram showing an example of composition of an ophthalmology device concerning an embodiment. It is the schematic for demonstrating operation | movement of the ophthalmologic apparatus which concerns on embodiment. It is the schematic for demonstrating operation | movement of the ophthalmologic apparatus which concerns on embodiment. It is the schematic for demonstrating operation | movement of the ophthalmologic apparatus which concerns on embodiment. It is a flowchart showing the operation example of the ophthalmologic apparatus which concerns on embodiment. It is a flowchart showing the operation example of the ophthalmologic apparatus which concerns on embodiment.

  An embodiment of the present invention will be described. The ophthalmologic apparatus according to the embodiment may be an arbitrary ophthalmic measurement apparatus, an arbitrary ophthalmologic imaging apparatus, or an arbitrary multifunction machine in which the ophthalmic measurement apparatus and the ophthalmologic imaging apparatus are combined. Examples of the ophthalmologic measurement device include a refractometer, a keratometer, a visual function inspection device, and a tonometer. Examples of the ophthalmologic photographing apparatus include an OCT apparatus, a fundus camera, and an SLO.

<Configuration>
FIG. 1 shows a configuration example of an ophthalmologic apparatus according to the embodiment. The ophthalmologic apparatus 1 according to the embodiment has a function of acquiring data of the eye E, that is, a function of photographing the eye E and / or a function of measuring characteristics of the eye E.

  The ophthalmologic apparatus 1 includes a processor 10, an optical unit 20, a face support unit 70, a first drive mechanism 80A, a second drive mechanism 80B, and a user interface (UI) unit 90. Note that only one of the first drive mechanism 80A and the second drive mechanism 80B may be provided.

  The optical unit 20 is provided with a measurement optical system 30 and an anterior eye camera 60. The measurement optical system 30 includes an objective lens 40. Two or more anterior eye cameras 60 are provided at different positions.

(Processor 10)
The processor 10 executes various types of information processing. In this specification, the “processor” is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), or a programmable logic device (for example, SPLD (Simple ProLigL). It means a circuit such as Programmable Logic Device (FPGA) or Field Programmable Gate Array (FPGA).

  The processor 10 implements the functions according to the embodiment by reading and executing a program stored in a storage circuit or a storage device, for example. At least a part of the memory circuit or the memory device may be included in the processor 10. Further, at least a part of the memory circuit or the memory device may be provided outside the processor 10. Processing that can be executed by the processor 10 will be described later. The processor 10 includes a control unit 11, a storage unit 12, and a data processing unit 13.

(Control unit 11)
The control unit 11 executes control of each unit of the ophthalmologic apparatus 1. In particular, the control unit 11 controls the optical unit 20, the first drive mechanism 80A, and the second drive mechanism 80B. In the case of manual alignment, the control unit 11 receives an operation on the user interface unit 90 by the user and controls at least one of the first drive mechanism 80A and the second drive mechanism 80B, thereby causing the optical unit 20 and the eye E to be examined. Move relative. In the case of auto alignment, the control unit 11 moves the optical unit 20 and the eye E relative to each other by controlling at least one of the first drive mechanism 80A and the second drive mechanism 80B based on the control conditions described later. The control that can be executed by the control unit 11 will be described later.

(Storage unit 12)
The storage unit 12 stores various data. The data stored in the storage unit 12 includes data (measurement data, imaging data, etc.) acquired by the measurement optical system 30, information on the subject and the eye to be examined, and the like. The storage unit 12 may store various computer programs and data for operating the ophthalmologic apparatus 1. The storage unit 12 stores various types of data that are used and referred to in processing that will be described later. The storage unit 12 includes the storage circuit and the storage device described above.

(Data processing unit 13)
The data processing unit 13 executes various data processing. In particular, the data processing unit 13 analyzes an image acquired by the anterior segment camera 60. The data processing unit 13 is provided with a position specifying unit 131 and a distance specifying unit 132. These operations will be described later.

(Optical unit 20)
In addition to the configuration shown in FIG. 1, the optical unit 20 may be provided with an optical system (observation optical system, imaging optical system, etc.) and an alignment optical system for imaging the eye E from the front. In addition, a configuration for performing focusing of the measurement optical system 30 may be provided. Further, the optical unit 20 may include a light source (anterior eye illumination light source) for illuminating the anterior eye portion Ea of the eye E.

(Measurement optical system 30)
The measurement optical system 30 has a configuration for measuring the characteristics of the eye E. The measurement optical system 30 has a configuration corresponding to the functions (measurement function, imaging function, etc.) provided by the ophthalmologic apparatus 1. For example, the measurement optical system 30 includes a light source, an optical element (an optical member, an optical device), an actuator, a mechanism, a circuit, a display device, a light receiving element, an image sensor, and the like. The configuration of the measurement optical system 30 may be the same as that of a conventional ophthalmic apparatus. At least a part of the measurement optical system 30 may be disposed outside the optical path. For example, when a keratometer function for measuring the corneal curvature is provided, a light source (keratring light source) for projecting a ring-shaped light beam or a concentric light beam onto the cornea is disposed immediately before the eye E to be examined. For example, when a function of an optical coherence tomometer for acquiring a tomographic image of the eye E and an intraocular distance is provided, the objective lens 40 and the eye E to change the focal position of the interference optical system. A front lens that can be inserted and removed is provided between them.

  The measurement optical system 30 may include a configuration for providing a function associated with the inspection. For example, a fixation optical system for projecting a target (fixation target) for fixing the eye E on the fundus of the eye E may be provided.

(Anterior eye camera 60)
The anterior eye camera 60 images the anterior eye part Ea of the eye E to be examined. As described above, two or more anterior eye cameras 60 are provided at different positions. Each anterior eye camera 60 is, for example, a video camera that performs moving image shooting at a predetermined frame rate. The two or more anterior segment cameras 60 photograph the anterior segment substantially simultaneously from different directions.

  In this embodiment, as shown in FIGS. 2 and 3, two anterior eye cameras 60A and 60B are provided. FIG. 2 is a top view showing the positional relationship between the eye E and the anterior eye cameras 60A and 60B. The + Y direction indicates vertically upward, and the + Z direction indicates the optical axis direction of the measurement optical system 30 and the direction from the measurement optical system 30 toward the eye E. FIG. 3 is a side view showing the positional relationship between the eye E and the anterior eye cameras 60A and 60B. The anterior eye cameras 60 </ b> A and 60 </ b> B are provided at positions that are out of the optical path of the measurement optical system 30. Hereinafter, the two anterior eye cameras 60 </ b> A and 60 </ b> B may be collectively represented by reference numeral 60.

  The number of the anterior segment camera may be an arbitrary number of 2 or more as long as the anterior segment can be photographed substantially simultaneously from two different directions. One anterior eye camera may be arranged coaxially with the measurement optical system 30.

  “Substantially simultaneously” indicates that a photographing timing shift that allows negligible eye movement is allowed in photographing with two or more anterior segment cameras. Thereby, an image when the eye E is in the same position (orientation) can be acquired by two or more anterior segment cameras.

  In addition, although shooting with two or more anterior eye cameras may be moving image shooting or still image shooting, this embodiment will specifically describe the case of moving image shooting. In the case of moving image shooting, the above-described substantially simultaneous anterior ocular shooting can be realized by controlling the shooting start timing to match or by controlling the frame rate and shooting timing of each frame. On the other hand, in the case of still image shooting, this can be realized by controlling to match the shooting timing.

  In the present embodiment, two or more photographed images obtained substantially simultaneously by two or more anterior eye cameras 60 are used for alignment (alignment) between the optical unit 20 and the eye E to be examined. The alignment includes Z alignment in the optical axis direction (Z direction) of the measurement optical system 30, and XY alignment in the X direction (horizontal direction) and the Y direction (vertical direction) orthogonal to the Z direction.

  In the present embodiment, for each of two or more captured images obtained by the anterior eye camera 60, a feature position corresponding to a feature part of the eye E (for example, the center of the pupil or the cornea (center of gravity)) is specified, and the anterior eye part Based on the position of the camera 60 and the identified characteristic positions in the two or more captured images, the three-dimensional position of the characteristic part of the eye E is determined. In the case of manual alignment, the user moves the optical unit 20 and the eye E relative to each other by operating the user interface unit 90 so that the displacement of the position of the characteristic part of the eye E to the alignment reference position is canceled. . In the case of auto-alignment, the control unit 11 moves the optical unit 20 three-dimensionally so that the displacement of the position of the characteristic part of the eye E with respect to the alignment reference position is cancelled. The alignment reference position is a position where the optical axis of the measurement optical system 30 substantially coincides with the axis of the eye E and the distance of the measurement optical system 30 with respect to the eye E is a predetermined working distance. Here, the working distance is a predetermined value called a working distance of the objective lens 40, and means a distance between the eye E and the measurement optical system 30 at the time of examination using the measurement optical system 30.

  In the following embodiments, the distance between the measurement optical system 30 and the eye E for acquiring data of the eye E is the distance between the optical unit 20 housing the measurement optical system 30 and the eye E. Or it shall be able to be equated with the distance between the objective lens 40 and the eye E to be examined.

(Face support part 70)
The face support unit 70 includes a member for supporting the subject's face. For example, the face support unit 70 includes a forehead pad on which the subject's forehead abuts and a chin rest on which the subject's chin is placed. The face support unit 70 may include only one of the forehead support and the chin rest, or may include other members.

(First drive mechanism 80A, second drive mechanism 80B)
The first drive mechanism 80A moves the optical unit 20 under the control of the control unit 11. The first drive mechanism 80A can move the optical unit 20 three-dimensionally. The first drive mechanism 80A includes, for example, a mechanism for moving the optical unit 20 in the X direction, a mechanism for moving in the Y direction, and a mechanism for moving in the Z direction, as in the conventional case. The first drive mechanism 80A includes a plurality of stepping motors (drive means) that drive a mechanism for moving in the X, Y, and Z directions. For example, the control unit 11 can move the optical unit 20 by a movement amount corresponding to the number of pulses by supplying a drive signal having a predetermined number of pulses to the stepping motor. The first drive mechanism 80A may include a rotation mechanism that rotates the optical unit 20 in a plane (horizontal plane, vertical plane, etc.) including the optical axis of the optical unit 20.

  The second drive mechanism 80 </ b> B moves the face support unit 70 under the control of the control unit 11. The second drive mechanism 80B can move the face support unit 70 three-dimensionally. The second drive mechanism 80B includes, for example, a mechanism for moving the face support unit 70 in the X direction, a mechanism for moving in the Y direction, and a mechanism for moving in the Z direction. Similar to the first drive mechanism 80A, the second drive mechanism 80B includes a plurality of stepping motors (drive means) that drive a mechanism for moving in the X, Y, and Z directions. For example, the control unit 11 can move the face support unit 70 by a movement amount corresponding to the number of pulses by supplying a driving signal having a predetermined number of pulses to the stepping motor. Further, the second drive mechanism 80B may include a rotation mechanism for changing the direction of the face support unit 70 (or a member included therein). When a plurality of members are provided on the face support unit 70, the second drive mechanism 80B may be configured to move these members individually. For example, the second drive mechanism 80B may be configured to individually move the forehead rest and the chin rest. As described above, generally, at least one of the first drive mechanism 80A and the second drive mechanism 80B is provided. In order to correspond to the size of the face of the subject, only the chin rest may be movable in the Y direction.

(User interface unit 90)
The user interface unit 90 provides functions for exchanging information between the ophthalmologic apparatus 1 and the user, such as information display, information input, and operation instruction input. The user interface unit 90 provides an output function and an input function. Examples of a configuration that provides an output function include a display device such as a flat panel display, an audio output device, a print output device, and a data writer that writes to a recording medium. Examples of a configuration that provides an input function include an operation lever, a button, a key, a pointing device, a microphone, and a data writer. The user interface unit 90 may include a device in which an output function and an input function such as a touch panel display are integrated. The user interface unit 90 may include a graphical user interface (GUI) for inputting and outputting information.

(Details of the data processing unit 13)
Details of the data processing unit 13 will be described. As described above, the data processing unit 13 is provided with the position specifying unit 131 and the distance specifying unit 132.

(Position specifying unit 131)
The position specifying unit 131 analyzes two or more photographed images obtained substantially simultaneously by the anterior eye cameras 60A and 60B, so that an area corresponding to the characteristic part of the eye E to be examined depicted in each photographed image is obtained. Specify the position (three-dimensional position). When the anterior eye cameras 60A and 60B perform moving image shooting, the position specifying unit 131 specifies the position of the area from each frame. The position specifying unit 131 can specify the position of the region by analyzing the pixel value of the captured image. When the captured image is a luminance image, the position specifying unit 131 specifies an image region (pixel) corresponding to a feature part based on the distribution of luminance values in the captured image. For example, when the characteristic part is the pupil center, the position specifying unit 131 specifies an image region (pupil region) corresponding to the pupil of the eye E based on the distribution of pixel values (such as luminance values) of the captured image. . In general, since the pupil is drawn with lower brightness than other parts, the pupil area can be specified by searching for the low brightness image area. At this time, the pupil region may be specified in consideration of the shape of the pupil. That is, the pupil region can be specified by searching for a substantially circular and low luminance image region. Next, the position specifying unit 131 specifies the center position of the specified pupil region. Since the pupil is substantially circular as described above, the contour of the pupil region can be specified, the center position of the contour (an approximate circle or approximate ellipse) can be specified, and this can be used as the pupil center. Further, the center of gravity of the pupil region may be obtained, and the position of the center of gravity may be used as the center of the pupil. Even when the feature position corresponding to another feature part is specified, it is possible to specify the feature position based on the distribution of pixel values of the photographed image in the same manner as described above. Note that the index light beam may be projected onto the cornea, and the position of the reflected image based on the reflected light of the index light beam from the cornea may be specified as the feature position.

  Further, the position specifying unit 131 can specify the feature position as a three-dimensional position as shown in FIGS. 2 and 3, the distance (baseline length) between the two anterior eye cameras 60A and 60B in the XY directions is represented by “B”. The distance (index image distance) between the baselines of the two anterior eye cameras 60A and 60B and the pupil center P as the characteristic part of the eye E is represented by “H”. The distance (screen distance) between each anterior eye camera 60A and 60B and the screen plane is represented by “f”.

  In such an arrangement state, the resolution of the image captured by the anterior eye cameras 60A and 60B is expressed by the following equation. Here, Δp represents pixel resolution.

Resolution in the XY direction: ΔXY = H × Δp / f
Resolution in the Z direction: ΔZ = H × H × Δp / (B × f)

  The position specifying unit 131 considers the positional relationship shown in FIGS. 2 and 3 with respect to the positions (known) of the two anterior eye cameras 60A and 60B and the position of the pupil center P in the two captured images. The position of the pupil center P is specified by applying the known trigonometry. The position of the pupil center P is specified as the position of the eye E (three-dimensional position).

  The position of the eye E to be examined specified by the position specifying unit 131 is sent to the control unit 11. As described above, the control unit 11 adjusts the optical axis of the measurement optical system 30 to the axis of the eye E based on the obtained position of the eye E and determines the optical axis of the measurement optical system 30 for the eye E to be examined. The first drive mechanism 80A and / or the second drive mechanism 80B are controlled so that the distance becomes a predetermined working distance.

(Distance identification unit 132)
The distance specifying unit 132 specifies the distance (optical system / eye distance) between the position of the eye E to be inspected specified by the position specifying unit 131 and the measurement optical system 30 (objective lens 40). For example, the position specifying unit 131 specifies the position of the eye E in a three-dimensional coordinate system based on the reference position of the optical unit 20 (the position of the objective lens 40 of the measurement optical system 30). In this case, the distance specifying unit 132 can specify the optical system / inspection eye distance by a known distance calculation process in the three-dimensional coordinate system. The distance specifying unit 132 sequentially obtains the optical system / eye distance using the position of the eye E to be sequentially specified.

  The control unit 11 controls the optical unit 20 and the eye E by controlling at least one of the first drive mechanism 80A and the second drive mechanism 80B based on the optical system / eye distance determined by the distance specifying unit 132. Move relative. At this time, the control unit 11 sequentially updates the control conditions for at least one of the first drive mechanism 80A and the second drive mechanism 80B based on the optical system / eye distance to be examined sequentially identified by the distance identifying unit 132. The control unit 11 can control at least one of the first drive mechanism 80A and the second drive mechanism 80B based on the updated control condition.

  The control unit 11 updates the control conditions as necessary, and controls the first drive mechanism 80A and the first drive mechanism 80A and the optical unit 20 so that the optical unit 20 does not approach more than a predetermined distance with respect to the eye E based on the optical system / eye distance. Control at least one of the second drive mechanisms 80B. Specifically, the control unit 11 sequentially obtains the movable distance in the direction in which the optical unit 20 approaches the eye E from the optical and eye distances that are sequentially specified, and determines the movable distance in the direction. The optical unit 20 and the eye E to be examined are relatively moved within the range. Obtaining the movable distance corresponds to obtaining the movement limit position.

  For example, the movable distance is stored in the storage unit 12 or the like as the number of movable pulses of the drive signal supplied to at least one of the first drive mechanism 80A and the second drive mechanism 80B. Each time the control unit 11 drives at least one of the first drive mechanism 80A and the second drive mechanism 80B, the control unit 11 subtracts the number of pulses corresponding to the amount of movement from the number of movable pulses stored in the storage unit 12 or the like. The number of movable pulses updated in (1) is again stored in the storage unit 12 or the like. Thereby, the remaining movement amount is recognized from the number of movable pulses stored in the storage unit 12 or the like.

  FIG. 4 is an explanatory diagram of the movable distance according to the embodiment. 4, parts that are the same as those in FIG. 1 are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

  When the optical system / inspection eye distance L1 is obtained by the distance specifying unit 132, the control unit 11 obtains a distance MC1 obtained by subtracting the known working distance WD of the objective lens 40 from the optical system / inspection eye distance L1 as a movable distance. . When the optical system / eye distance L1 is sequentially specified by the distance specifying unit 132, the control unit 11 sequentially obtains the distance MC1 that is the movable distance. When the position of the eye E is changed during the execution of the Z alignment, when the distance specifying unit 132 newly specifies the optical system / eye distance L2, the control unit 11 determines the objective lens from the optical system / eye distance L2. A distance MC2 obtained by subtracting the working distance WD of 40 is obtained as a new movable distance. The control unit 11 can relatively move the optical unit 20 and the eye E within the range of the movable distance (MC2) in the Z direction. The movable distance may be set larger (far) or smaller (near) than the working distance WD. In a device having a short working distance WD, it is desirable to set the movable distance larger than the working distance WD in order to further reduce the risk of contact.

  The optical unit 20 or the measurement optical system 30 is an example of an “optical system” according to the embodiment. At least one of the first drive mechanism 80A and the second drive mechanism 80B is an example of the “drive unit” according to the embodiment. The user interface unit 90 is an example of an “operation unit” according to the embodiment. The anterior eye camera 60 is an example of an “imaging unit” according to the embodiment.

<Operation>
The operation of the ophthalmologic apparatus 1 will be described.

  5 and 6 are flowcharts showing an operation example of the ophthalmologic apparatus 1. 5 and 6 illustrate an example of the Z alignment operation of the ophthalmologic apparatus 1 according to the embodiment. 5 and FIG. 6 will be described assuming that XY alignment has been completed.

(S1)
In response to an instruction for starting imaging of the anterior eye portion Ea of the eye E to be examined by the user or the control unit 11, the control unit 11 controls the anterior eye camera 60 to control the eye E to be examined. Acquisition of a moving image of the anterior segment Ea is started. The anterior eye cameras 60A and 60B form captured images (frames) at a predetermined frame rate. The captured images are sequentially input to the data processing unit 13.

(S2)
The control unit 11 causes the position specifying unit 131 to specify the position of the eye E to be examined. As described above, the position specifying unit 131 analyzes two or more captured images obtained substantially simultaneously by the anterior segment cameras 60A and 60B in S1, and thus the eye E to be examined depicted in each captured image. The three-dimensional position of the region corresponding to the pupil center is specified as the position of the eye E.

(S3)
The control unit 11 determines whether or not the position of the eye E is specified in S2. For example, the control unit 11 determines that the position specifying unit 131 has not specified the position of the eye E when the position specifying unit 131 cannot specify the pupil region due to blinking of the eye E or changing the line of sight. When it is determined in S2 that the position of the eye E has been specified (S3: Y), the operation of the ophthalmologic apparatus 1 proceeds to S4. When it is determined in S2 that the position of the eye E is not specified (S3: N), the operation of the ophthalmologic apparatus 1 proceeds to S9.

(S4)
When it is determined in S3 that the position of the eye E has been specified (S3: Y), the control unit 11 determines the optical system / eye distance to be measured between the optical unit 20 and the eye E as a distance specifying unit. 132. Next, as described above, the control unit 11 obtains the movable distance (number of movable pulses) in the direction in which the optical unit 20 approaches the eye E based on the specified optical / eye distance. For example, the movable distance is updated from the initial value to the newly obtained movable distance.

(S5)
The control unit 11 receives an operation on the user interface unit 90 by the user, and determines a movement amount of at least one of the first drive mechanism 80A and the second drive mechanism 80B according to the operation content. In the present embodiment, for example, the control unit 11 moves the optical unit 20 by controlling the first drive mechanism 80A according to the user's operation content. The control unit 11 determines whether or not the position when the optical unit 20 is moved by the amount of movement is within the movable distance obtained in S4. The determination as to whether or not the distance is within the movable distance range may be made based on the number of pulses included in the drive signal output to the first drive mechanism 80A. When it is determined that the distance is within the movable distance range (S5: Y), the operation of the ophthalmologic apparatus 1 proceeds to S6. When it is determined that it is not within the range of the movable distance (S5: N), the operation of the ophthalmologic apparatus 1 proceeds to S12.

(S6)
When it is determined in S5 that the position of the optical unit 20 after the movement is within the range of the movable distance obtained in S4 (S5: Y), the control unit 11 performs the optical unit by the movement amount determined in S5. 20 is moved. For example, the control unit 11 can move the optical unit 20 by the movement amount by supplying a driving signal having the number of pulses corresponding to the movement amount to the first drive mechanism 80A.

(S7)
The control unit 11 determines whether or not the Z alignment is completed based on the position of the optical unit 20 moved in S6 and the position of the eye E. For example, the control unit 11 completes the Z alignment when the difference between the distance in the Z direction between the position of the optical unit 20 and the position of the eye E and the working distance of the objective lens 40 is equal to or less than a predetermined threshold. Is determined. When it is determined that the Z alignment is completed (S7: Y), the operation of the ophthalmologic apparatus 1 proceeds to S8. When it is determined that the Z alignment has not been completed (S7: N), the operation of the ophthalmologic apparatus 1 proceeds to S2.

(S8)
When it is determined that the Z alignment is completed in S7 (S7: Y), the control unit 11 controls the measurement optical system 30 according to the function of the measurement optical system 30 to perform measurement on the eye E. . Thus, the operation of the ophthalmologic apparatus 1 ends (END).

(S9)
When it is determined in S3 that the position of the eye E is not specified (S3: N), the control unit 11 receives an operation on the user interface unit 90 by the user, and the first drive mechanism 80A and the first drive mechanism 80A and the first The amount of movement of at least one of the two drive mechanisms 80B is determined. The control unit 11 determines whether or not the position when the optical unit 20 is moved by the amount of movement is within the range of the obtained movable distance (or the movable distance as the initial value). The determination as to whether or not the distance is within the movable distance range may be made based on the number of pulses included in the drive signal output to the first drive mechanism 80A. When it is determined that the distance is within the determination movable distance (S9: Y), the operation of the ophthalmologic apparatus 1 proceeds to S10. When it is determined that it is not within the range of the movable distance (S9: N), the operation of the ophthalmologic apparatus 1 proceeds to S11.

(S10)
When it is determined in S9 that the position of the optical unit 20 after the movement is within the movable distance range (S9: Y), the control unit 11 moves the optical unit 20 by the movement amount determined in S9. The operation of the ophthalmologic apparatus 1 proceeds to S2.

(S11)
When it is determined in S9 that the position of the optical unit 20 after the movement is not within the movable distance range (S9: N), the control unit 11 moves at least in the direction in which the optical unit 20 approaches the eye E to be examined. Stop. The operation of the ophthalmologic apparatus 1 proceeds to S2.

(S12)
When it is determined in S5 that the position of the optical unit 20 after the movement is not within the range of the movable distance obtained in S4 (S5: N), the control unit 11 approaches the optical unit 20 to the eye E to be examined. Notify that it cannot move in the direction. This notification may be information output to the user interface unit 90, sound output, lamp lighting, or the like.

  In addition, the control part 11 can change the display mode with respect to the user interface part 90 according to whether it is in the range of the movable distance. Thereby, the user can easily grasp the distance between the optical unit 20 and the eye E to be examined.

  Moreover, the control part 11 may change the display mode with respect to the user interface part 90 according to the number of movable pulses. As a result, the user can easily grasp how much relative movement between the optical unit 20 and the eye E is possible.

(S13)
Subsequently, the control unit 11 determines whether or not to end the operation of the ophthalmologic apparatus 1. For example, in response to an instruction for ending the operation of the ophthalmic apparatus 1 being made by the user or the control unit 11, the control unit 11 determines whether or not to end the operation of the ophthalmic apparatus 1. When it is determined that the operation of the ophthalmologic apparatus 1 is to be ended (S13: Y), the operation of the ophthalmologic apparatus 1 is ended (end). When it is determined that the operation of the ophthalmic apparatus 1 is not finished (S13: N), the operation of the ophthalmic apparatus 1 proceeds to S2.

  As described above, according to the embodiment, the control conditions including the movable distance can be sequentially updated every time an image of the anterior segment Ea of the eye E is obtained. When the position of the eye E cannot be specified by blinking the eye E or changing the line of sight, the optical unit 20 is within the range of the movable distance (or the initial movable distance) updated immediately before. And the eye E to be examined can be relatively moved.

<Action and effect>
The operation and effect of the ophthalmologic apparatus according to the embodiment will be described.

  The ophthalmologic apparatus (1) according to the embodiment includes an optical system (measurement optical system 30), a drive unit (at least one of the first drive mechanism 80A and the second drive mechanism 80B), a distance specifying unit (132), and a control. Part (11). The optical system is used for acquiring data of the eye to be examined (E). The drive unit relatively moves the optical system and the eye to be examined in the optical axis direction (Z direction) of the optical system. The distance specifying unit repeatedly specifies the distance between the optical system and the eye to be examined (optical system / eye distance to be examined). The control unit sequentially updates the control condition for the drive unit based on the distance sequentially specified by the distance specifying unit, and controls the drive unit based on the updated control condition, thereby controlling the optical system and the eye to be examined. Move relative.

  In such a configuration, the distance between the optical system and the eye to be examined is repeatedly specified, the control conditions for the drive unit are sequentially updated based on the specified distance, and the optical system is updated based on the updated control conditions. Relative movement with the eye to be examined. As a result, even when the subject's eye blinks, the line of sight changes, or the like, the optical system and the subject's eye can be relatively moved based on the control conditions updated immediately before. Therefore, even while the eye is blinking or the line of sight is being changed, the optical system and the eye to be examined are relatively moved based on the control conditions updated immediately before. High-accuracy alignment is possible without frequent stops during alignment.

  Further, in the ophthalmologic apparatus according to the embodiment, the control unit may control the driving unit based on the distance so that the optical system does not approach the eye to be examined more than a predetermined distance.

  According to such a configuration, an ophthalmologic apparatus capable of high-precision alignment while avoiding contact between the optical system and the eye to be examined without frequently stopping during alignment between the optical system and the eye to be examined. Will be able to provide.

  In the ophthalmologic apparatus according to the embodiment, the control unit sequentially obtains the movable distance in the direction in which the optical system approaches the eye to be examined based on the sequentially identified distance, and the range of the movable distance in the above direction The drive unit may be controlled within.

  According to such a configuration, high-accuracy alignment can be performed without stopping during the alignment between the optical system and the eye to be examined as long as it is within the movable distance range.

  In the ophthalmologic apparatus according to the embodiment, the optical system may include the objective lens (40), and the control unit may obtain a distance obtained by subtracting the working distance of the objective lens from the above distance as the movable distance.

  According to such a configuration, high-accuracy alignment is possible while ensuring the working distance of the objective lens without frequently stopping during alignment with the eye to be examined.

  In addition, the ophthalmologic apparatus according to the embodiment includes two or more imaging units (anterior eye cameras 60, 60A, 60B) for simultaneously imaging the anterior eye part (Ea) of the eye to be examined from different directions, and two or more imagings. A position specifying unit (131) that specifies a three-dimensional position of the eye to be examined by analyzing two or more captured images obtained simultaneously by the unit, and the distance specifying unit includes the optical system and the three-dimensional position The distance between them may be specified.

  According to such a configuration, it becomes possible to photograph the eye to be examined from a wide range, and even if the distance between the optical system and the eye to be examined is long to some extent, the optical system It becomes possible to perform highly accurate alignment with the eye to be examined.

  In addition, the ophthalmologic apparatus according to the embodiment includes an operation unit (user interface unit 90), and the control unit controls the drive unit according to an operation using the operation unit to relatively move the optical system and the eye to be examined. May be.

  According to such a configuration, even while the eye is blinking or the line of sight is being changed, the optical system and the eye to be examined are relatively moved based on the control conditions updated immediately before. High-accuracy alignment is possible without giving a sense of incongruity to the operation.

<Modification>
The embodiment described above is merely a typical example of the present invention. Therefore, arbitrary modifications (omitted, replacement, addition, etc.) within the scope of the present invention can be made as appropriate.

  When a plurality of measurements (photographing) are performed sequentially, alignment can be performed immediately before each measurement. For example, when performing corneal curvature measurement (kerato measurement), eye refractive power measurement (ref measurement), and subjective examination (visual measurement) in this order, before kerato measurement, between kerato measurement and reflex measurement, and It is possible to perform alignment between the reflex measurement and the subjective examination. Further, alignment may be performed immediately before a part of a plurality of measurements.

  In the embodiment, the Z alignment can be performed by the method of the present embodiment, and the XY alignment can be performed by another method. For the XY alignment, for example, a technique disclosed in JP2013-248376A may be applied. That is, XY alignment based on the pupil can be performed based on two or more captured images of the anterior segment acquired substantially simultaneously. Alternatively, when an observation optical system for photographing the subject's eye from the front is provided, it is known based on an index image (bright spot image), a pupil center position, and the like in the front image of the anterior segment obtained thereby. XY alignment can be performed.

  The embodiment is not limited to the method for specifying the distance between the optical unit 20 and the eye E to be examined. For example, the relative position between the optical unit 20 and the eye E may be detected by a so-called optical lever method, and the distance between the optical unit 20 and the eye E may be specified. In addition, a sensor that detects the position of the eye E may be provided, and the distance between the optical unit 20 and the eye E may be specified using the detection result of the sensor.

DESCRIPTION OF SYMBOLS 1 Ophthalmology apparatus 11 Control part 12 Memory | storage part 13 Data processing part 20 Optical unit 30 Measurement optical system 40 Objective lens 60, 60A, 60B Anterior eye part camera 70 Face support part 80A 1st drive mechanism 80B 2nd drive mechanism 90 User interface part 131 Position specifying part 132 Distance specifying part E Eye Ea to be examined Anterior eye part

Claims (6)

An optical system for acquiring data of the eye to be examined;
A drive unit that relatively moves the optical system and the eye to be examined in the optical axis direction of the optical system;
A distance specifying unit that repeatedly specifies the distance between the optical system and the eye to be examined;
The control condition for the drive unit is sequentially updated based on the distance sequentially specified by the distance specifying unit, and the drive unit is controlled based on the updated control condition, thereby controlling the optical system and the target. An ophthalmologic apparatus comprising: a control unit that relatively moves the optometer. The ophthalmologic apparatus according to claim 1, wherein the control unit controls the driving unit so that the optical system does not approach the eye to be examined more than a predetermined distance based on the distance. The control unit sequentially obtains a movable distance in a direction in which the optical system approaches the eye to be examined based on the sequentially specified distance, and moves the driving unit within the range of the movable distance in the direction. The ophthalmic apparatus according to claim 1, wherein the ophthalmic apparatus is controlled. The optical system includes an objective lens,
The ophthalmic apparatus according to claim 3, wherein the control unit obtains a distance obtained by subtracting a working distance of the objective lens from the distance as the movable distance. Two or more imaging units for simultaneously imaging the anterior segment of the eye to be examined from different directions;
A position specifying unit for specifying a three-dimensional position of the eye to be examined by analyzing two or more captured images obtained simultaneously by the two or more imaging units;
Including
The ophthalmologic apparatus according to claim 1, wherein the distance specifying unit specifies a distance between the optical system and the three-dimensional position. Including the operation part,
The said control part controls the said drive part according to operation using the said operation part, and moves the said optical system and the said to-be-tested eye relatively. The any one of Claims 1-5 characterized by the above-mentioned. The ophthalmic apparatus according to item.

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