KR20060083408A - Slip ring laser illuminator for speed dome - Google Patents

Abstract

The present invention relates to a surveillance camera installed in a protective dome and having a new pan, tilt, zoom, rotation and lighting functions. It provides a lighting system that can use a speed dome camera system with minimal weight gain and conventional motor design, but is used in situations where ambient lighting is insufficient for visibility. The laser lighting system is divided into two parts: a power source installed outside the speed dome, a heavy element of a heat sink laser beam generator, and a light fiber optic cable output stage installed near the speed dome camera.

Description

Slip ring laser illuminator for speed dome {SLIP RING LASER ILLUMINATOR FOR SPEED DOMES}

The present invention relates to a surveillance camera installed in a protective dome and having a new pan, tilt, zoom, rotation and lighting functions.

Speed dome cameras are quite popular in the CCTV market.

Typical dome cameras with CCTV cameras installed in the dome housing usually lack pan, tilt, zoom, or rotate functions. Conventional surveillance devices usually have this function, in which case the motor is mounted on a large bracket and the camera housing and fixtures are mounted on it. Speed dome cameras, on the other hand, feature fast pan, tilt, zoom and rotation of the camera inside a domed shield.

Typical specifications for Speed Dome cameras include a 1 / 4-inch color CCD, 48dB S / N ratio, 64 preset positions and 480 TV lines. Improvements include 128 preset positions, 50dB S / N ratio, 2x optical zoom module, zero color rolling and horizontal and vertical image inversion.

Advanced Speed Dome models feature day and night camera mode weatherproof housings. Examples of high-end products include an optical sensor that detects when the ambient light is less than 5 lux, and a switch to switch from normal color mode to black and white mode to understand the resolution. Auxiliary lightings include nighttime and surveillance infrared. Although powerful fixtures can be installed outside the Speed Dome, they often illuminate a wide range unnecessarily regardless of where the Speed Dome aims. When an LED illuminator is used inside the speed dome, the weight increases, putting pressure on the speed performance of the speed dome camera. LED lighting requires a heatsink, and even a vent to keep it at the lighting temperature.

A typical dome camera is characterized by its rotational speed of 10 degrees to 12 degrees per second. However, it is common to adjust the rotational speed of the speed dome camera to 0.3 to 240 degrees per second or more, and often the fan speed is 360 degrees per second and the tilting speed is 90 degrees per second. These cameras feature zoom lenses and autofocus to capture the target in detail and precisely. Speed dome cameras can have very fast turn angular speeds due to their compact and lightweight construction.

The disadvantages of these products were lack of lighting performance or uneconomical lighting. It is not economical for the Speed Dome to rotate 360 degrees to illuminate the entire area.

It is also quite difficult to install lighting fixtures on platforms such as moving cameras. This is because the lighting device is larger and heavier than the light weight camera. As a result, the dome was getting bigger and the motor was getting bigger and the angular velocity had to be reduced.

Another problem that needs to be overcome in installing a luminaire in a dome camera is internal reflection, in which the light from the illuminator is reflected inside the dome and enters the camera lens. This adversely affects the information from the light returned through the dome from the site being monitored. Although the shading plate between the illuminator and the camera increases the speed dome load, it is not desirable, but mainly because of the effective side, the shading plate must be abutted on the inner side of the dome, so the inside of the dome is likely to be scratched by the shading plate. Therefore, another solution, such as the present invention, is needed.

The two surveillance systems have distinct advantages and disadvantages. Conventional pan / tilt systems can focus the lighting required at the aimed location, but are slow and aesthetically pleasing and look bad. The speed dome is fast and looks good, but if you do not light up the entire target area with a large luminaire, the camera cannot focus the light on the aiming point. In this case, the aesthetic appearance of the speed dome is broken by the large luminaire.

Speed dome cameras employ a lighting system that adopts the existing motor design with minimal weight increase, so that it can be used even when the ambient light is insufficient for monitoring.

The laser lighting system is divided into two parts: a power source installed outside the speed dome, a heavy element of a heat sink laser beam generator, and a light fiber optic cable output stage installed near the speed dome camera.

The biggest feature of the present invention is to propagate only the laser beam through the optical slip ring, not the power of the laser, to significantly reduce the weight. This eliminates the weight and space required for the laser's large heatsink and power supply from the dome, allowing for fast camera turnover. For example, a large 20-watt laser (equivalent to 1000 LEDs) can Too heavy to use Laser equipment is large on its own, but requires a large heatsink to keep the equipment within the operating temperature range. However, any powerful laser light comes from a flexible fiber end 1 mm in diameter and 4 m in length, and this fiber is cold enough to touch. The emitted laser beam passes through a dispersion lens mounted on a carriage in which a camera is installed inside the speed dome. The optical fiber is contained in a curved pipe-shaped lamppost-style column, which limits the curvature of the fiber between the laser beam output stage and the remote laser, which is arranged near the surveillance camera.

If the speed dome rotates back and forth within a limited angle or 360 degrees, the laser beam travels through the fiber optic cable.

To rotate the speed dome continuously, an optical slip ring is used to deliver the laser beam through the lightweight fiber. When the laser power is disconnected from the rotating carriage for the speed dome camera, the slip ring enables continuous rotation. Since the optical slip ring is a connection, the laser beam is transmitted from the fixed tubing to the movable lightweight fiber optic output, so that the speed dome's internal mechanism can rotate continuously in the carriage. An optical slip ring is also called an optical fiber rotary joint. The slip ring allows the light to continue to be transmitted while rotating along the optical fiber axis without twisting the optical cable.

Current optical slip ring technology enables joints of 20mm in length and 6.8mm in diameter, with insertion loss lower than 2dB and return loss greater than 50dB. This joint is optimized for pressure compensation below 10,000 and its maximum speed is 100 rmp, which meets or exceeds the operating conditions of the speed dome. Although continuous transmission is possible, the laser may be pulsed through the optical slip ring during the time that the slip ring is stopped at a predetermined stop portion corresponding to the circular optical fiber branch number, where the input and output optical fibers are aligned.

The optical slip ring aligns the open end of the fiber optic cable with the rotary opposite open end of the fiber optic cable inside the sealed housing. Light passes through a narrow air gap from the open end of the fiber optic cable connected to the light source to the opposite rotatable open end of the fiber optic cable where light is dispersed to illuminate the desired area.

The optical slip ring can also provide low power to enffjTK video signals and cameras with multiple concentric channel type electrical slip rings. Electrical slip rings are sometimes referred to as electrical rotary connectors, electrical swivels or electrical rotary joints. It is an electromechanical device that transmits power and electrical signals from fixed water cells to rotating objects. Electrical rotary connectors can be used in all electromechanical systems that require unlimited continuous / intermittent rotation while transferring power or data. Electric slip rings generally have a series of bushes in contact with the rotating ring. The video signal is converted into electrical information inside the camera and then passes through a channel of an electrical slip ring having a lower weight than the optical slip ring, compared to the light collected by the lens passing through the optical slip ring of optical fibers. However, by separating the light collected in the second channel of the optical fiber slip ring, it is possible to maximize the weight reduction of the rotating portion of the speed dome. Without this slip ring, the optical fiber or electrical surge in the rotating shaft is twisted by rotation, and if the rotation continues, the wire will eventually tighten, break and stop the system.

The standard electrical slip ring is made of silver with an operating current of 7.5 amps and an operating voltage of 1,000 volts.

When the optical slip ring and the electric slip ring are combined to form an electro-optic slip ring, the electrical signal and the power may be transmitted through the rotary interface as well as the optical signal. By placing multiple electrical rings, it is possible to select power or data transmission via electro-optic slip rings.

A diffuser lens must be used to illuminate the output, or the laser beam will exit the optical fiber at an angle of about 10 degrees. The lens can be driven electrically to change the angle of illumination.

To solve the problem of internal reflection in the dome, that is, the light from the fixture is reflected inside the dome and enters the camera lens, the laser output is pulsed and the light immediately after each pulse reflecting the light inside the dome. Synchronize the camera so that it does not collect, but delay the camera to collect only the light that passes through the dome and returns from the surveillance site. Modern timing devices are nanosecond-adjustable, which makes this possible despite relatively short normal viewing distances and light speeds.

In the case of a fiber laser illuminator for a surveillance camera speed dome according to a preferred embodiment of the present invention:

1. Shining light inside surveillance camera speed dome by spreading laser beam through fiber optic cable;

2. The heavy elements of the laser, including the power supply and heatsink, shall be installed outside the surveillance camera speed dome, preferably on the support base of the speed dome, where the support is a curved bend where the speed dome hangs;

3. Install the fiber optic cable output end in the vicinity of the surveillance camera to match the camera, and fire the laser beam from the cable output end in the direction that the surveillance camera aims, and place the dispersion lens near the fiber optic cable output end to aim the laser beam. The dispersion lens is mounted on the motorized sub carriage, and the dispersion angle can be changed by adjusting the position of the dispersion lens to the sub carriage;

4. Install the fiber optic cable output end, the dispersion lens, and the camera on the rotating carriage inside the speed dome, and install the camera on the carriage through an electric pivot mechanism that pivots the camera perpendicular to the carriage rotation surface inside the speed dome;

5. The laser beam is propagated by the optical fiber cable through the optical slip ring to shine the light from the optical fiber cable output end inside the surveillance camera speed dome, and one side of the optical slip ring rotates with the surveillance camera installed inside the speed dome, and the optical slip The ring aligns the open end of the fiber optic cable with the rotating opposite open end of the fiber optic cable inside the sealed housing, thus crossing the narrow air gap from the open end of the fiber optic cable attached to the laser to the rotationally opposite open end of the other fiber optic cable. The laser beam is moved, and the laser beam is distributed to illuminate a desired area from the output end of the optical fiber cable;

7. Surrounding the optical slip ring with multiple channel type electric slip rings and bushes, supplying power for surveillance cameras and low power for video signals from the fixed support to the rotating carriage with surveillance cameras installed inside the speed dome;

8. The laser beam is pulsed and does not collect light until the time required for each pulse of the laser beam to exit the fiber optic cable output and reflect from the inside of the speed dome to the camera, but the laser beam reflects from the target to the surveillance camera. Surveillance cameras are synchronized to collect light after the required time, and the length of each laser pulse is shorter than the time it takes for the light to travel from the outside of the speed dome to the target and travel to the surveillance camera. The returning light does not overlap inside the speed dome with light reflected from the inner side of the speed dome from the end of the laser beam pulse from the optical fiber output end;

9. The laser operates at 20 watts of power, and the diameter of the fiber optic cable is about 1 mm.

1 is a side cross-sectional view of a slip ring laser illuminator for a speed dome with a rotating camera;

FIG. 2 is a bottom view of FIG. 1 with the lower cover of the dome removed; FIG.

3 is a side cross-sectional view of the device of FIG. 1 connected to a lamp post with laser power and the rotary camera tilted about 30 degrees;

4 is a perspective view of the device of FIG. 3 showing an illumination state aligned with a speed dome camera;

5 is a block diagram of a pulse delay system that ameliorates the internal reflection problem of the apparatus of FIG.

6 is a side view showing a timing relationship of the pulse delay system of FIG.

1-3, the zoom camera 2 in the speed dome 1 is installed in a pan / tilt mechanism with a motor 3, an extender 39, and a pivot hinge 56, which is a dome base ( It is installed in the carriage 4 which rotates quickly with respect to 5) and eventually rotates with respect to the surface on which the dome base is installed. The optical fiber tube output end 6 is installed in the camera 2 so that the laser beam emitted from this is matched to the direction in which the zoom camera 2 faces. The power source 11 installs the remote laser 10 with the heat sink 12 outside the speed dome 1. The laser output is connected to the inside 14 of the optical slip ring 15 through the main optical fiber cable 13. The outer ring 16 of the slip ring 15 receives the laser output and sends the laser output to the optical fiber tube output terminal 6. The interior 14 of the slip ring 15 rotates with respect to the exterior 16 of the slip ring, illuminating the target with a laser beam through the dispersion lens.

In Fig. 1, the rotary electric inner contact ring of the electric slip ring 30 surrounding the optical slip ring channel is in contact with two pairs of positive / negative outer contact rings 35-38 at points 31, 32, 33 and 34. Power and video output signals are supplied to the rotating mechanism in the speed dome. Thus, the video signal lines 40 and 41 of the camera can transmit signals to the output video signal lines 42 and 43 through contacts at 37, 33 and 38 and 34, respectively. Similarly, the tilt motor control lines 44 and 45 are also connected to the input tilt control lines 46 and 47 through contacts at 35, 31 and 36, 32. Since the carriage 4 is rotated by the rotation motor 48, the camera 2 and the laser beam output end 6 installed in the carriage also rotate through the coupling mechanism 61 (belt or gear type). The rotary motor 48 is electrically operated by the power supply and the control lines 49 and 50. The optical fiber cable 13 and the wires 42, 43, 46, 47, 49 and 50 are all contained in the pipe 51 in the lamp post 66. Thus, the camera can be powered and remotely control additional functions such as pan / tilt or zoom lens motors regardless of the rotation of the speed dome. The output of the camera itself is also sent through the electric slip ring, so the output cable is not twisted even when the camera is rotated several times instead of forward and backward.

According to FIG. 1, the laser beam moves along the optical fiber cable 13 in the direction of the arrow 52. 53, the inside of the optical slip ring 15 can be seen through the break, and the laser beam flows in the direction of the arrow 54 from the fixed upper portion of the optical slip ring 15 to the lower rotation part connected to the rotary carriage 4. The laser beam continues to the exit end 6 in the direction of the arrow 57. The mounting brackets 58 and 59 fix the optical fiber cable output unit 60 to the camera 2 near the output terminal 6. The snap rim 75 of the transparent dome 74 is fitted to the locking rim 77 of the proximal end 76.

1 and 2, the base 5 is fixed by fitting the rim 72 of the speed dome base 5 to the rim 71 of the upper cap 70 having the overlapping rim 71. Rain water falling on the cap 70 due to the rim 73 of the edge falls directly to the ground without touching the transparent dome 74 of the speed dome 1.

According to FIG. 3, the power supply 11 includes a large capacitor 62 and a heat sink 12 for storing and discharging a large amount of current. It is preferable to place the laser power source outside the speed dome, and also to serve as a weight at the lower end 65 of the lamp post 66. The laser 10 itself is installed in the lamppost 66 for the stability of the speed dome 1 fixed to the end 67 of the lamppost 66. The laser beam generated by the laser 10 is sent to the optical slip ring 15 of the speed dome 1 along the optical fiber cable 13 in the conduit 51 inside the lamp post 66. The laser power cable 78 and video control / output cable 79 enter the base 80 of the lamppost from below.

5 and 6, the laser pulse 81 emerges from the optical fiber output terminal 6 at the time T1. The zoom camera 2 is turned off for the time T1 to T2 it takes for the entire laser pulse 81 to go from the output end 6 to the wall surface 82 of the dome and back to the camera 2. Next, the camera is turned on for a longer period of time T2 to T3 when the pulse 81 reaches the monitoring site 83 and returns to the camera 2. Repeat this sequence. Since the distance to the monitoring site 83 is usually in the real life situation, the resolution optimization module 84 is used to compare the effects while changing T2 in consideration of reflection and changing T3 little by little.

According to FIG. 1, the dispersion lens 7 is fixed near the optical fiber output end 6, and the laser beam emitted from the output end is dispersed at an angle similar to the condensing angle of the lens 8 of the camera 2. The dispersion lens 7 may be provided in the motorized sub carriage 85, in which case the position of the lens is adjusted to affect the angle at which the laser beam is dispersed toward the monitoring site.

Claims (21)

An optical fiber laser illuminator for a speed dome of a surveillance camera, characterized by shining a laser beam from inside the surveillance camera speed dome through an optical fiber cable. The optical fiber laser illuminator for a speed dome of a surveillance camera according to claim 1, wherein the weight elements of the laser including a power source and a heat sink are installed outside the surveillance camera speed dome. The optical fiber laser illuminator for a speed dome of a surveillance camera according to claim 2, wherein a power supply and a heat sink of the laser are provided at a bottom of a support of the surveillance camera speed dome. The optical fiber laser illuminator for a speed dome of a surveillance camera according to claim 3, wherein the support part has a curved pillar shape, and the surveillance camera speed dome is suspended there. The optical fiber laser illuminator for a speed dome of a surveillance camera according to claim 1, wherein an optical fiber cable output end is arranged near the surveillance camera so as to be aligned with the surveillance camera, and the laser beam is emitted from the output end in a direction in which the surveillance camera is aimed. The optical fiber laser illuminator for a speed dome of a surveillance camera according to claim 1, wherein a dispersion lens is provided near the optical fiber cable output terminal to distribute the laser beam emitted from the optical fiber cable output terminal in the direction in which the camera is aimed. The optical fiber laser illuminator for a speed dome of a surveillance camera according to claim 1, wherein a dispersion lens is provided in the electric subcarriage to change the dispersion angle of light while changing the position of the dispersion lens with respect to the optical fiber cable output terminal. The optical fiber laser illuminator for a speed dome of a surveillance camera according to claim 1, wherein the optical fiber cable output end, the dispersion lens, and the camera are installed in a carriage rotating inside the speed dome. The optical fiber laser illuminator for a speed dome of a surveillance camera according to claim 8, wherein the camera is mounted on the carriage through an electric pivot mechanism that pivots the camera at a right angle with respect to the carriage rotation surface inside the speed dome. The optical fiber according to claim 1, wherein a laser beam is sent to an optical slip ring contact through an optical fiber cable to send light from an optical fiber cable output end in the surveillance camera speed dome, and one side of the optical fiber slip ring can rotate with a surveillance camera installed in the speed dome. Fiber optic laser illuminator for speed dome of surveillance camera. 12. The sealed housing of claim 10, wherein the laser beam passes through a small air gap from the open end of the optical fiber cable attached to the laser to the rotationally opposite open end of the other optical fiber cable from which the laser beam is dispersed. The rotating open end of the optical fiber cable and the opposite open end of the optical fiber cable are aligned by the optical slip ring. 12. The surveillance camera according to claim 11, wherein the optical slip ring coincides with the open end of the optical fiber cable and the rotationally opposite open end of the optical fiber cable in the sealed housing so that the center of the optical fiber cable coincides with the rotation axis of the opposite open end. Fiber laser illuminator for Speeddo. 13. The system of claim 12, wherein the slip ring is surrounded by a plurality of channel type electric slip rings and bushes to supply the low power for video signals and the power for the surveillance cameras from the fixed support to the rotatable carriage in which the surveillance camera is installed in the speed dome. Optical fiber laser illuminator for speed dome of surveillance camera. 2. The laser beam of claim 1, wherein the laser beam is pulsed and does not collect light until the time required for each pulse of the laser beam to exit the fiber optic cable output and reflect from the inner surface of the speed dome to the camera. The optical fiber laser illuminator for the speed dome of the surveillance camera, characterized in that the surveillance camera is synchronized to collect the light after the time required to reflect the surveillance camera. 15. The method of claim 14, wherein the length of each laser pulse is shorter than the time it takes to reach the target from the outside of the speed dome and then travel to the surveillance camera so that light that returns during the pulse that the camera collects is emitted from the optical fiber output stage. The optical fiber laser illuminator for the speed dome of a surveillance camera, characterized in that the light reflected from the inner side of the speed dome from the end of the laser beam pulse and the speed do not overlap inside. The optical fiber laser illuminator for a speed dome of a surveillance camera according to claim 1, wherein the laser operates at a power of 20 W or more, and an inner diameter of the optical fiber cavil is 1 mm. The optical fiber laser illuminator for a speed dome of a surveillance camera according to claim 1, wherein the length of the optical fiber cable is up to 4 m from the laser to the output end. The method according to claim 4, wherein the optical fiber cable output end is installed near the surveillance camera in accordance with the surveillance camera and the dispersion lens is installed near the optical fiber cable output end so that the laser beam from the optical fiber cable output end is dispersed in the aimed direction. Fiber optic laser illuminator for speed dome of surveillance camera. The method of claim 18, a) The laser beam is sent to the optical slip ring through the optical fiber cable to shine the light from the optical fiber cable output terminal inside the surveillance camera speed dome, and one side of the optical slip ring can rotate with the surveillance camera installed inside the surveillance camera speed dome. ; b) The optical slip ring matches the open end of the optical fiber cable with the rotary opposite open end of the optical fiber cable within the sealed housing, from the open end of the optical fiber cable attached to the laser to the rotary opposite open end of the other optical fiber cable. The laser beam moves across a narrow air gap, which is distributed to illuminate the desired area from the output end of the optical fiber cable; c) inside the housing where the optical slip ring is sealed, the open end of the optical fiber cable coincides with the rotary opposite open end of the optical fiber cable such that the center of the optical fiber cable coincides with the rotation axis of the opposite open end relative to the open end; d) Surveillance cameras, characterized by a plurality of channel type electric slip rings and bushes that surround the optical slip ring and supply power for surveillance cameras and low power for video signals from a fixed support to a rotating carriage with surveillance cameras installed inside the speed dome. Fiber laser illuminator for Speeddo. 19. The laser beam of claim 18, wherein the laser beam is pulsed and does not collect light until the time required for each pulse of the laser beam to exit the optical fiber cable output and reflect from the inner surface of the speed dome to the camera. The camera is synchronized to collect light after the time required to reflect from the camera to the camera, and the length of each laser pulse is shorter than the time it takes for the light to travel from the outside of the speed dome to the target and then to the camera. The optical fiber laser illuminator for a speed dome of a surveillance camera, characterized in that the light returned during the pulse of collecting light does not overlap inside the speed dome and light reflected from the inner side of the speed dome from the end of the laser beam pulse from the optical fiber output. 20. The optical fiber cable of claim 19, wherein the optical fiber cable output end, the dispersion lens, and the camera are installed in a carriage rotating inside the speed dome, wherein the laser beam is pulsed, and each pulse of the laser beam exits the optical fiber cable output end. The camera does not collect light until the time needed to reflect from the side to the camera has passed, but the surveillance camera is synchronized to collect light after the time required for the laser beam to reflect from the target to the surveillance camera, with the length of each laser pulse The light reflected from the inside of the speed dome from the end of the laser beam pulse from the optical fiber output end is shorter than the time it takes to reach the target from the outside and travel to the surveillance camera. Persimmon characterized by not overlapping inside the speed dome Domyong speed fiber laser illuminator of the camera.

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