Camera platform apparatus

Abstract

To provide a universal head device for a camera capable of maintaining the rotation angle of a camera part and manually adjusting the angle.SOLUTION: A camera platform device for a camera includes a driving motor for rotating a camera unit, a driving bevel gear that is rotated by the driving motor, a driving force transmission mechanism that rotates while partially meshing with the driving bevel gear, a braking member that applies a rotational friction torque to the driving force transmission mechanism, and an elastic member that presses the driving force transmission mechanism in a direction in which the driving force transmission mechanism comes into contact with the braking member. And is displaced in a direction away from the braking member.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a camera pan head device suitable for outdoor surveillance cameras and the like. [Background technology]

[0002] Currently, surveillance cameras are used in a variety of locations. Outdoor surveillance cameras are used continuously for long periods of time, regardless of weather or season, so they require a wide operating temperature range (temperature performance) and waterproofing.

[0003] Some outdoor surveillance cameras are used in combination with an electric pan head that can change the shooting direction electrically. Some surveillance cameras used in combination with an electric pan head patrol multiple registered shooting locations. Outdoor surveillance cameras can also patrol and shoot for most of the day.

[0004] In camera platform types where the camera unit is fixed to the top, the center of gravity of the camera unit is located away from the tilt rotation axis, so depending on the tilt shooting angle, the rotation torque due to the misalignment of the camera unit's center of gravity increases. If the tilt angle of the camera unit suddenly changes when power is off or during installation, it can cause malfunctions and be dangerous if there are workers nearby, so it is necessary to maintain the tilt angle even when power is off.

[0005] On the other hand, when fixing the camera unit to the camera platform, the tilt angle must be adjusted manually. Therefore, there is a demand for a camera platform that has a rotational friction torque greater than the rotational torque caused by the misalignment of the camera unit's center of gravity and that can be adjusted manually.

[0006] Another factor is that surveillance cameras are required to support PoE (Power over Ethernet) to simplify installation and reduce implementation costs. PoE compatibility allows cameras to be used with just a LAN cable, eliminating the need for a separate power source.

[0007] There are several PoE standards, each of which specifies the amount of power that can be used. The camera unit and head cannot be used unless they are below this specified power, so they are also required to consume low power. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 5904752 Summary of the Invention [Problem to be solved by the invention]

[0009] Patent Document 1 describes a configuration for reducing jitter in captured images when decelerating using a camera platform with a braking device. The braking device in Patent Document 1 has a threaded portion on the motor shaft, which, in combination with a nut, acts as a brake on the rotating part by biasing a friction member against the rotating part.

[0010] Therefore, if the power goes out while the brake is released (during pan / tilt operation), the brake state will remain in place, and the tilt angle cannot be maintained, causing the camera's shooting angle to suddenly change, which may result in malfunction.

[0011] In view of the above-mentioned problems, one of the objects of the present invention is to provide a camera pan head device that is capable of maintaining the rotation angle of the camera unit and that allows the angle to be manually adjusted. [Means for solving the problem]

[0012] In camera pan head devices, A drive motor for rotating the camera unit; a driving bevel gear rotated by the driving motor; a driving force transmission mechanism that rotates while partially meshing with the driving bevel gear; a braking member for applying a rotational friction torque to the driving force transmission mechanism; an elastic member that presses the driving force transmission mechanism in a direction that brings the driving force transmission mechanism into contact with the braking member, The driving force transmission mechanism is characterized in that it is displaced in a direction away from the braking member by a thrust force generated between the driving bevel gear and the driving motor when the driving motor rotates. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a camera pan head device that is capable of maintaining the rotation angle of the camera unit and also allows the angle to be manually adjusted. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view of a surveillance camera 1 according to an embodiment of the present invention. [Figure 2] 1A is a side view of a surveillance camera 1 according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view. [Figure 3] 1A and 1B are cross-sectional views of a surveillance camera according to an embodiment of the present invention. [Figure 4] 1 is a partial perspective view of a surveillance camera according to an embodiment of the present invention. [Figure 5] FIG. 2 is an exploded perspective view of a motor unit 300 of a surveillance camera according to an embodiment of the present invention. [Figure 6] FIG. 2 is a cross-sectional view of a motor unit 300 of a surveillance camera according to an embodiment of the present invention. [Figure 7] FIG. 2 is an enlarged cross-sectional view of the periphery of a drive gear 310 of a motor unit 300 of a surveillance camera according to an embodiment of the present invention. [Figure 8] FIG. 2 is an enlarged cross-sectional view of the periphery of a drive gear 310 when a drive motor 301 of a surveillance camera according to an embodiment of the present invention is rotating. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments. In each drawing, the same members or elements are designated by the same reference numerals, and duplicate descriptions will be omitted or simplified.

[0016] Fig. 1 is a perspective view of a surveillance camera 1 according to an embodiment of the present invention, Fig. 2(A) is a side view of the surveillance camera 1 according to an embodiment of the present invention, and Fig. 2(B) is a cross-sectional view. The arrows in Fig. 2(A) and (B) indicate the shooting direction of the surveillance camera 1. Fig. 2(A) shows a side view when shooting in the horizontal direction, and Fig. 2(B) shows a cross-sectional view when shooting diagonally downward.

[0017] The surveillance camera 1 of this embodiment is an outdoor surveillance camera that is installed on, for example, the exterior wall of a building or a utility pole. The surveillance camera 1 has a camera unit 10 and a camera platform device 20. Inside the camera unit 10, a lens, an imaging element, and the like (not shown in detail) are arranged. The camera platform device 20 functions as a camera platform device.

[0018] The camera platform device 20 comprises a tilt rotation unit 100, a pan rotation unit 200, and a fixed unit 400. The fixed unit 400 is a part that is fixed to an installation location such as a utility pole or a wall. The pan rotation unit 200 is configured to be able to pan rotate relative to the fixed unit 400.

[0019] The tilt rotation unit 100 is configured to be tilt rotatable relative to the pan rotation unit 200. The camera unit 10 is fixed relative to the tilt rotation unit 100. In this embodiment, the pan rotation and tilt rotation can be electrically operated.

[0020] The pan rotation unit 200 is composed of a pan rotation table 201, a side cover 202, a motor unit 300 (see FIG. 4), an electric board (not shown), etc. Images captured by the camera unit 10 are transmitted to the outside via the electric board.

[0021] 2 indicates the position of the center of gravity of the camera unit 10. In a surveillance camera configured as in this embodiment in which the camera unit 10 is fixed to the top of the camera platform device 20, the position of the center of gravity of the camera unit 10 is offset from the tilt rotation axis of the camera unit 10. Therefore, as shown in FIG. 2(B), depending on the tilt angle at which shooting is performed, a rotational torque due to the offset of the center of gravity of the camera unit 10 is applied to the tilt drive unit.

[0022] When power is supplied, it is possible to maintain the tilt shooting angle by exciting the drive motor 301 described below, but if the tilt shooting angle is maintained solely by the rotational torque of the excitation, the tilt shooting angle cannot be maintained if power to the surveillance camera 1 is interrupted.

[0023] Generally, surveillance cameras are operated for long periods of time and are sometimes used constantly in patrol mode, which is a mode in which the camera monitors multiple preset points (shooting directions) by panning and tilting sequentially at specified time intervals.

[0024] In this patrol mode, if the tilt angle of the surveillance camera 1 suddenly changes, it may cause a malfunction. Also, since it is dangerous if there are people nearby during installation, it is necessary to maintain the shooting angle of the surveillance camera 1 even when power is off.

[0025] 3(A) and (B) are cross-sectional views of a surveillance camera according to an embodiment of the present invention, showing the state when the camera unit 10 is attached to the camera platform device 20. Camera units 10 of various sizes with different lens and sensor performance can be attached to the camera platform device 20. The arrows in FIGS. 3(A) and (B) indicate the shooting direction of the surveillance camera 1.

[0026] Mounting screw holes are provided on the underside of the camera unit 10. When the surveillance camera 1 is facing horizontally, the mounting screws 102 are inaccessible, so when mounting the camera unit 10, the orientation of the camera unit 10 must be changed manually.

[0027] In the surveillance camera 1 configured in this embodiment, as shown in Figures 3(A) and 3(B), it is necessary to attach the camera unit 10 to the camera platform device 20 while changing the tilt direction of the camera unit 10 up and down. The tilt rotation unit 100 is composed of a tilt rotation base 101 and screws 102. A through hole for attaching the camera unit 10 is provided in the tilt rotation base 101, and the camera unit 10 is fixed in place using the screws 102.

[0028] Fig. 4 is a partial perspective view of the surveillance camera according to the embodiment of the present invention, showing a state in which the side cover 202 has been removed from the pan rotation unit 200. Fig. 5 is an exploded perspective view of the motor unit 300 of the surveillance camera according to the embodiment of the present invention.

[0029] A tilt drive unit, an electric board (not shown), and the like are arranged inside pan rotation unit 200. The tilt drive unit is made up of motor unit 300, drive gear 306, belt 104, large pulley 103, and the like.

[0030] The drive gear 306 has a gear that meshes with the drive gear 310 in the motor unit 300, and belt teeth 314 that mesh with the belt 104. In this embodiment, the belt 104 is a toothed belt.

[0031] The large pulley 103 is pivotally supported on the tilt rotating base 101 and rotates integrally with the camera unit 10. The rotational torque generated by the motor unit 300 passes through the drive gear 306, belt teeth 314, belt 104, and large pulley 103 to tilt the camera unit 10.

[0032] The driving motor 301 is a tilt driving motor for rotating the camera unit 10. In this embodiment, the driving motor 301 is, for example, a brushless DC motor. The driving bevel gear 302 is a gear attached to the shaft of the driving motor 301, and is rotated by the driving motor 301.

[0033] Driving motor 301 is fixed to holder 303 by screws 304. Shafts 305 and 307 are press-fitted and fixed at predetermined positions in holder 303. Driving gear 306 is inserted into shaft 305 and arranged to be rotatable.

[0034] A driving gear 310 is inserted and rotatably disposed on the shaft 307. A sliding washer 308 and a coil spring 309 are inserted and disposed on the shaft 307 between the shaft 307 and the driving gear 310.

[0035] The coil spring 309 functions as an elastic member that presses the drive gear 310 and the like, which serve as a driving force transmission mechanism, in a direction that brings them into contact with the braking member 311. Note that the braking member 311 as an elastic member is not limited to a spring, and may be an elastic body such as rubber.

[0036] Cover 312 is fixed to holder 303 with screws 313. Cover 312 has through holes at predetermined positions, and shafts 305 and 307 are fitted into the through holes to fix both ends of the cover 312. Braking member 311 for applying rotational friction torque to the driving force transmission mechanism is disposed between cover 312 and drive gear 310, with shaft 307 inserted therethrough.

[0037] The driving gear 310 meshes with the driving bevel gear 302 and rotates around the shaft 307 as a rotation axis. The driving gear 310, which serves as a driving force transmission mechanism, has two gears: a bevel gear 310a that meshes with the driving bevel gear 302, and a spur gear 310b that meshes with the driving gear 306 at the subsequent stage.

[0038] The drive gear 310 functions as a drive force transmission mechanism that rotates while partially meshing with the drive bevel gear 302. The drive force transmission mechanism in this embodiment is for tilting and rotating the camera unit, and the drive gear 306, belt 104, large pulley 103, etc. also function as a drive force transmission mechanism for tilting and rotating the camera unit.

[0039] However, the configuration of the drive force transmission mechanism is not limited to that of the embodiment, and any configuration of the drive force transmission mechanism may be used as long as it is capable of tilting or panning the camera unit.

[0040] Driving gear 306 has a spur gear that meshes with spur gear 310b of driving gear 310, and belt teeth 314 that mesh with belt 104. Driving gear 306, together with a mechanical section consisting of belt 104 and large pulley 103, can also rotate from the driven side, making it possible to manually adjust the tilt angle of camera unit 10. In other words, the driving force transmission mechanism can rotate by applying force to camera unit 10.

[0041] Fig. 6 is a cross-sectional view of motor unit 300 of a surveillance camera according to an embodiment of the present invention, and Fig. 7 is an enlarged cross-sectional view of the periphery of drive gear 310 of motor unit 300 of a surveillance camera according to an embodiment of the present invention. Drive gear 310 is held so as to be slidable in the axial direction of shaft 307.

[0042] Driving gear 310 is pressed by coil spring 309 and is in frictional contact with braking member 311, generating a braking torque when it is rotated, for example manually, from the driven side. The diameter at which braking member 311 is in frictional contact with driving gear 310 and the pressing force of coil spring 309 are set so as to exceed the braking torque that can maintain the tilt shooting angle, i.e., the maximum rotational torque that occurs when the center of gravity of camera unit 10 is shifted.

[0043] In this manner, in this embodiment, the rotational friction torque generated by contact between the driving force transmission mechanism such as the driving gear 310 and the braking member 311 is set to be larger than the rotational torque caused by the displacement of the center of gravity of the camera unit.

[0044] Furthermore, the driving gear 310 is engaged with the driving bevel gear 302 with an appropriate backlash at the position where it contacts the braking member 311. When the driving motor 301 rotates, the driving gear 310 receives a radial force from the driving bevel gear 302 as it rotates, and at the same time receives a thrust force 315 in the opposite direction to the pressing direction of the coil spring 309, as shown in FIG.

[0045] This force 315 in the thrust direction reduces the pressing force of the coil spring 309 and reduces the braking torque generated between the drive gear 310 and the braking member 311. The force in the thrust direction increases in proportion to the drive torque of the drive motor 301.

[0046] When the driving torque of the driving motor 301 exceeds a predetermined torque, the force 315 in the thrust direction exceeds the pressing force of the coil spring 309 , and the driving gear 310 displaces (slides) in a direction away from the braking member 311 .

[0047] That is, in this embodiment, the driving force transmission mechanism is displaced in a direction away from the braking member 311 by a thrust force generated between the driving motor 301 and the driving bevel gear 302 when the driving motor 301 rotates.

[0048] The spur gear 310b of the drive gear 310, which meshes with the drive gear 306, is a spur gear that does not hinder sliding movement in the thrust direction, and the drive gear 310 slides until the end of the spur gear 310b contacts the sliding washer 308. The amount of sliding movement at that time is small, and as shown in Figure 7, the distance between the drive bevel gear 302 and the bevel gear 310a of the drive gear 310 increases slightly, but the meshed state is maintained.

[0049] A force obtained by subtracting the pressing force of the coil spring 309 from the thrust force generated by the drive motor 301 acts as a rotational friction force between the drive gear 310 and the sliding washer 308 .

[0050] The diameter of the sliding washer 308 is configured to be smaller than the diameter at which the drive gear 310 and the braking member 311 are in contact. Furthermore, the sliding washer 308 is configured from a member having a smaller coefficient of friction than the braking member 311. Therefore, even when the drive torque of the drive motor 301 is large and the force in the thrust direction is large, the rotational friction torque applied to the drive gear 310 can be kept small.

[0051] 8 is an enlarged cross-sectional view of the periphery of drive gear 310 when drive motor 301 of the surveillance camera according to the embodiment of the present invention is rotating. Cover 312 has a spherical shape 312a (see FIGS. 5 and 8) centered on the rotation axis of drive gear 310. Cover 312 also has a protrusion 312b (see FIG. 7) that prevents rotation of braking member 311.

[0052] The braking member 311 has a spherical shape 311a that abuts against the inner surface of the spherical shape 312a of the cover 312, and has a rotation prevention hole 311b that fits into the rotation prevention protrusion. The rotation prevention hole 311b is shaped as an elongated hole toward the drive motor 301, and the braking member 311 can rotate at an angle toward the drive motor 301.

[0053] When drive motor 301 rotates, force 315 is applied to drive gear 310 in the thrust direction, causing it to tilt by the amount of the clearance between it and shaft 307. If drive gear 310 rubs against braking member 311 while tilted, uneven wear occurs, making the braking force unstable and reducing durability.

[0054] In contrast to this, in this embodiment, the braking member 311 is configured to be tiltable and rotatable toward the driving motor 301. Therefore, even when the driving gear 310 is tilted by a force 315 in the thrust direction, the braking member 311 can follow the tilt, making it possible to prevent uneven wear.

[0055] That is, the braking member 311 is tiltable with respect to the rotation axis of the driving force transmission mechanism. Therefore, when the driving force transmission mechanism is tilted by a thrust force 315 generated between the driving force transmission mechanism and the driving bevel gear 302, uneven wear on the contact surface between the driving force transmission mechanism and the braking member can be suppressed.

[0056] On the other hand, when the surveillance camera 1 or drive motor 301 is de-energized, the tilt angle of the camera unit 10 is maintained by the braking torque generated between the braking member 311 and the drive gear 310. When the tilt angle of the camera unit 10 is manually adjusted, a thrust force 315 is generated between the drive gear 310, which is rotated from the driven side, and the drive bevel gear 302.

[0057] However, because the drive motor 301 is not energized and the detent torque is small, the generated thrust force 315 is small. Therefore, the torque required to manually adjust the camera unit 10 is approximately the same as the braking torque.

[0058] Furthermore, when the surveillance camera 1 is powered on, the driving torque required to tilt and rotate the camera unit 10 is the sum of the braking torque generated between the braking member 311 and the driving gear 310 and the rotational torque generated due to a shift in the center of gravity of the camera unit 10.

[0059] However, as the driving torque of the driving motor 301 increases, the braking torque decreases due to the generation of thrust force 315 in the driving gear 310. Furthermore, when a predetermined driving torque is exceeded, the driving gear 310 separates from the braking member 311 and the braking torque almost disappears, so only the rotational torque generated by the displacement of the center of gravity of the camera unit becomes the necessary driving torque.

[0060] That is, at tilt angles where the displacement of the center of gravity of the camera unit 10 is small, the braking torque is not fully released and a loss in the drive torque occurs, but at tilt angles where the displacement of the center of gravity of the camera unit 10 is large, the braking torque automatically disappears. Therefore, the camera unit 10 can be driven only by the torque required for tilt rotation.

[0061] As described above, according to this embodiment, it is possible to realize a surveillance camera that can maintain the tilt angle even when the power supply to the motor is turned off, while at the same time allowing the tilt angle to be stably adjusted manually during installation, etc. Furthermore, the surveillance camera according to this embodiment can automatically reduce braking torque without using a complex control mechanism, making it possible to reduce power consumption when the power is on.

[0062] In the above description of the embodiment, examples of maintaining the tilt angle, etc., have been described, but the present invention is not limited to this. For example, if the surveillance camera in Fig. 1 is positioned so that its up-down direction is horizontal, it is desirable to have a similar configuration for controlling the pan angle, and this embodiment also includes a case where tilt is replaced with pan.

[0063] Although the present invention has been described in detail above based on the preferred embodiments, the present invention is not limited to the above embodiments, and various modifications and combinations of the above embodiments are possible based on the spirit of the present invention, and are not excluded from the scope of the present invention. The present invention also includes the following combinations.

[0064] (Configuration 1) A camera pan head device comprising: a drive motor for rotating a camera unit; a drive bevel gear rotated by the drive motor; a drive force transmission mechanism that rotates by partially meshing with the drive bevel gear; a braking member that applies rotational friction torque to the drive force transmission mechanism; and an elastic member that presses the drive force transmission mechanism in a direction toward contact with the braking member, wherein the drive force transmission mechanism is displaced in a direction away from the braking member due to a thrust force generated between the drive bevel gear and the drive motor when the drive motor rotates.

[0065] (Configuration 2) The camera pan head device according to Configuration 1, wherein the drive force transmission mechanism is rotatable by applying a force to the camera unit.

[0066] (Configuration 3) The center of gravity of the camera unit is offset from the rotation axis of the camera unit, The camera pan head device described in configuration 1 or 2, characterized in that the rotational friction torque generated by contact between the drive force transmission mechanism and the braking member is set to be larger than the rotational torque caused by a shift in the center of gravity of the camera unit.

[0067] (Configuration 4) The braking member is tiltable with respect to the rotation axis of the driving force transmission mechanism, A camera pan head device according to any one of configurations 1 to 3, characterized in that when the driving force transmission mechanism is tilted due to the thrust force generated between the driving bevel gear and the driving force transmission mechanism, uneven wear of the contact surface between the driving force transmission mechanism and the braking member is suppressed.

[0068] (Configuration 5) The camera pan head device according to any one of configurations 1 to 4, wherein the drive force transmission mechanism has a bevel gear that meshes with the drive bevel gear.

[0069] (Configuration 6) The camera pan head device according to any one of configurations 1 to 5, wherein the drive force transmission mechanism is for tilting and rotating the camera unit. [Explanation of symbols]

[0070] 1: Surveillance camera 10: Camera section 20: Panhead device 100: Tilt rotation part 101: Tilt rotating platform 103: Large pulley 104: Belt 200: Pan rotation section 201: Bread turntable 202: Side cover 300: Motor unit 301: Drive motor 302: Drive bevel gear 305: Shaft 306: Drive gear 307: Shaft 308: Sliding washer 309: Coil spring 310: Drive gear 311: Braking parts 312: Cover

Claims

1. A drive motor for rotating the camera unit; a driving bevel gear rotated by the driving motor; a driving force transmission mechanism that rotates while partially meshing with the driving bevel gear; a braking member for applying a rotational friction torque to the driving force transmission mechanism; an elastic member that presses the driving force transmission mechanism in a direction that brings the driving force transmission mechanism into contact with the braking member, A camera pan head device characterized in that the drive force transmission mechanism is displaced in a direction away from the braking member due to a thrust force generated between the drive motor and the drive bevel gear when the drive motor rotates.

2. 2. The camera pan head device according to claim 1, wherein the driving force transmission mechanism is rotatable by applying a force to the camera unit.

3. the center of gravity of the camera unit is offset from the rotation axis of the camera unit; 2. The camera pan head device according to claim 1, wherein the rotational friction torque generated by contact between the drive force transmission mechanism and the braking member is set to be greater than the rotational torque caused by a shift in the center of gravity of the camera unit.

4. the braking member is tiltable with respect to a rotation axis of the driving force transmission mechanism, The camera pan head device according to claim 1, characterized in that when the driving force transmission mechanism is tilted due to the thrust force generated between the driving bevel gear and the driving force transmission mechanism, uneven wear of the contact surface between the driving force transmission mechanism and the braking member is suppressed.

5. 2. The camera pan head device according to claim 1, wherein the drive force transmission mechanism has a bevel gear that meshes with the drive bevel gear.

6. 2. The camera platform device according to claim 1, wherein the drive force transmission mechanism is for tilting and rotating the camera unit.

Images