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 driving transmission mechanism including a driving transmission element for transmitting a driving force of the driving motor, a braking member for applying a rotational friction torque to the driving transmission element, an elastic member for urging the braking member to come into contact with the driving transmission element, and a braking motor for moving the braking member from a first position where the braking member comes into contact with the driving transmission element to a second position where the braking member does not come into contact with the driving transmission element, when the braking member is at the second position, rotational torque applied to the braking motor by the elastic member is set to be larger than holding torque in non-excitation of the braking motor.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a camera platform 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 the 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 drive transmission mechanism including a drive transmission element for transmitting the drive force of the drive motor; a braking member for applying a rotational friction torque to the drive transmission element; an elastic member that biases the braking member so as to contact the drive transmission element; a braking motor for moving the braking member from a first position in contact with the drive transmission element to a second position out of contact with the drive transmission element, A camera pan head device characterized in that when the braking member is in the second position, the rotational torque applied to the braking motor by the elastic member is set to be greater than the holding torque of the braking motor when it is not excited. [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] FIG. 2 is a partial perspective view of a pan rotation unit 200 with a side cover 202 removed in 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 a perspective view of some components of a motor unit 300 according to an embodiment of the present invention. [Figure 8] FIG. 3 is a perspective view of a cover 305 and a holder 313 of a motor unit 300 according to an embodiment of the present invention. 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] Screw holes for mounting (not shown) 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 (not shown) 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 pan rotation unit 200 with the side cover 202 removed in the embodiment of the present invention. Fig. 5 is an exploded perspective view of the motor unit 300 of the surveillance camera in 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 203, belt 104, large pulley 103, coil spring 204, and the like.

[0030] The drive gear 203 has a gear that meshes with the drive gear 311 in the motor unit 300, and a small pulley with spur teeth that meshes with the belt 104. In this embodiment, the belt 104 is a toothed belt. The large pulley 103 is journaled on the tilt rotatable base 101 and rotates integrally with the camera unit 10.

[0031] The coil spring 204 is an elastic member that applies tension to the belt 104. The rotational torque generated by the motor unit 300 passes through the drive gear 203, the belt 104, and the large pulley 103 to tilt the camera unit 10.

[0032] Fig. 6 is a cross-sectional view of motor unit 300 of a surveillance camera according to an embodiment of the present invention, Fig. 7 is a perspective view of some components of motor unit 300 according to an embodiment of the present invention, and Fig. 8 is a perspective view of cover 305 and holder 313 of motor unit 300 according to an embodiment of the present invention.

[0033] The drive motor 301 is a drive motor for tilting and rotating the camera unit 10, and has an internal sensor (not shown) for detecting the angle of rotation. In this embodiment, the drive motor 301 is, for example, a brushless DC motor. The drive pinion 302 is a gear attached to the shaft of the drive motor 301.

[0034] A drive motor 301, a cover 305, etc. are fixed to the cover 303. A shaft 318 is disposed between the cover 303 and the cover 305, and a drive gear 311 is rotatably disposed therebetween.

[0035] In addition, a holder 313 is disposed between the cover 303 and the cover 305 so as to be movable in the axial direction (thrust direction) of the shaft 318. The cover 303 has a sliding surface for sliding with the drive gear 311. A screw 304 fixes the drive motor 301 to the cover 303. A screw 307 fixes the cover 305 to the cover 303.

[0036] The driving gear 311 meshes with the driving pinion 302 and rotates around the shaft 318. The driving gear 311 has a gear 311a that meshes with the driving pinion 302 and a gear 311b that meshes with the driving gear 203 at the subsequent stage.

[0037] Gears 311a and 311b provided on drive gear 311 are both spur gears, and can be manually rotated from camera unit 10, which is the driven side, together with the mechanism consisting of drive gear 203, belt 104, and large pulley 103.

[0038] That is, the drive transmission mechanism such as the tilt drive unit of this embodiment can rotate camera unit 10 by applying force to camera unit 10, and can manually adjust the tilt angle of camera unit 10. Drive gear 311 has two sliding surfaces: one sliding surface with cover 303 and the other sliding surface with sheet 312 of holder 313.

[0039] The holder 313 is provided with a first helical gear 314, a shielding plate 315, a sheet 312, etc. The holder 313 biases the driving gear 311 toward the cover 303 by the elastic force of the coil spring 317.

[0040] Holder 313 is movable in the thrust direction of shaft 318. First helical gear 314 meshes with gear 321a of second helical gear 321. Shielding plate 315 is a shielding plate used for position detection by a PI (Photo Interapter) unit 319 (see FIG. 7).

[0041] Sheet 312 is fixed to the main body of holder 313 with double-sided tape or the like. Sheet 312 is made of an elastic material such as soft rubber, and is used to increase the frictional force between drive gear 311 and holder 313.

[0042] Cover 305 is provided with rotation restricting portion 306 (see FIG. 8) at a contact point with holder 313. Holder 313 is provided with rotation restricting portion 316 (see FIG. 8) at a contact point with cover 305. Rotation restricting portion 306 and rotation restricting portion 316 allow holder 313 to rotate relative to cover 305 only within a predetermined angle range.

[0043] In this embodiment, the coil spring 317 is a compression coil spring disposed between the cover 305 and the holder 313, and biases the holder 313 toward the drive gear 311, which serves as a drive transmission element.

[0044] That is, the coil spring 317 functions as an elastic member that biases the braking member made up of the sheet 312, holder 313, etc. so that it comes into contact with the driving gear 311 serving as a drive transmission element. Note that the coil spring 317 serving as an elastic member is not limited to a spring, and may be an elastic body such as rubber. The driving gear 311 is rotatably held between the holder 313 and the cover 303.

[0045] Shaft 318 rotatably holds drive gear 311. The elastic force of coil spring 317 provides rotational friction between drive gear 311 and cover 303, and between drive gear 311 and holder 313. Shaft 318 holds holder 313 movably.

[0046] The second helical gear 321 is provided with a helical gear 321a that meshes with the first helical gear 314, and a gear 321b that meshes with a braking pinion 322. 323 is a braking motor, such as a stepping motor. The braking motor 323 has a holding torque (detent torque) when no current is applied due to an internal magnet. The braking pinion 322 is attached to the rotating shaft of the braking motor 323.

[0047] A second helical gear 321 is rotatably disposed between the metal plate 324 and the metal plate 327. A braking motor 323 is fixed to the metal plate 324 with a screw 325. A screw 326 fixes the metal plate 324 to the metal plate 327. A screw 328 fixes a unit consisting of the metal plate 327, the braking motor 323, etc. to the cover 303.

[0048] When braking motor 323 rotates in a first direction, for example, holder 313 moves in the thrust direction from the first position to the second position via braking pinion 322 and gears 321b and 321a of second helical gear 321. At the first position, drive gear 311 and holder 313 come into contact with each other, and a rotational friction force is generated by the elastic force of coil spring 317.

[0049] On the other hand, in the second position, the drive gear 311 and the holder 313 do not come into contact with each other, and no rotational frictional force is generated by the elastic force of the coil spring 317. Hereinafter, when the holder 313 is in the first position, it will also be expressed as the brake being ON, and when it is in the second position, it will also be expressed as the brake being OFF. Note that the braking motor 323 functions as a braking motor for moving the braking member from the first position, where it comes into contact with the drive transmission element, to the second position, where it does not come into contact.

[0050] A PI element that detects the movement of the holder 313 is arranged in the PI unit 319, and when the holder 313 is in the first position, the shielding plate 315 of the holder 313 enters the gap of the PI unit 319, and the output of the PI unit 319 becomes, for example, 0.

[0051] On the other hand, when the braking motor 323 rotates in, for example, the first direction, the holder 313 moves in the thrust direction and is displaced to the second position, whereby the shielding plate 315 comes out of the gap in the PI unit 319, and the output of the PI unit 319 becomes, for example, 1.

[0052] In this way, whether the holder 313 is in the first position or the second position is detected depending on whether the output of the PI unit 319 is 0 or 1. The PI unit 319 functions as a detection means for detecting the position of the braking member. Furthermore, when the detection means detects that the braking member has moved from the first position to the second position, the braking motor 323 may be changed from a rotating state to an excited state.

[0053] The tilt drive unit is made up of a motor unit 300, a drive gear 203, a belt 104, a large pulley 103, a coil spring 204, etc., and is therefore configured to be manually rotatable from the driven side as well. That is, tilt rotation can be performed manually by the user at the time of installation, etc.

[0054] As described above, the holder 313 is movable between a first position where it is in contact with the drive gear 311 and a second position where it is not in contact with the drive gear 311. At the first position, the drive gear 311 and the holder 313 are in contact with each other, generating a rotational friction torque.

[0055] At the second position, no rotational friction torque is generated because drive gear 311 and holder 313 are not in contact with each other. In addition, as braking motor 323 rotates in the first direction, holder 313 can be moved to the second position by a thrust load generated by meshing of first helical gear 314 and gear 321a of second helical gear 321, both of which are helical gears.

[0056] That is, the braking member can be moved from the first position to the second position by a thrust load generated by meshing with gear 321a, which is a helical gear rotated by braking motor 323.

[0057] When braking motor 323 is driven to rotate in the first direction, holder 313 can be moved to the second position and the brake can be turned off. The driving gear 311 functions as a driving transmission element for transmitting the driving force of the driving motor, and the tilt driving unit excluding driving motor 301 functions as a driving transmission mechanism. The driving transmission mechanism includes the driving transmission element.

[0058] When holder 313 is in the second position, the elastic force of coil spring 317 and rotational torque generated by first helical gear 314 and the like are applied to braking motor 323. When braking motor 323 is energized, holder 313 can be held in the second position by the rotation or excitation of braking motor 323.

[0059] On the other hand, the rotational torque generated by the elastic force of the coil spring 317 and the helical gear is configured to be larger than the holding torque when no current is applied (when not excited) to the braking motor 323. That is, in this embodiment, when the braking member is in the second position, the rotational torque applied to the braking motor by the elastic member is set to be larger than the holding torque when the braking motor is not excited.

[0060] As a result, when the power supply is cut off while the holder 313 is in the second position (brake OFF), the coil spring 317 overcomes the holding torque of the braking motor 323 when no power is supplied, and the holder 313 can return to the first position.

[0061] When the holder 313 returns to the first position, the holder 313 comes into contact with the drive gear 311, so that a rotational friction load can be obtained (brake ON), and the tilt shooting angle can be maintained.

[0062] The total of the rotational friction torques generated by contact between the drive gear 311 and the cover 303 and between the drive gear 311 and the holder 313 is set to be larger than the rotational torque caused by the displacement of the center of gravity of the camera unit 10 .

[0063] That is, in this embodiment, the rotational friction torque generated by contact between the drive 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, so the tilt shooting angle can be maintained even if the power is turned off.

[0064] Furthermore, if the braking motor 323 is rotated in the opposite direction to the rotation direction when moving the holder 313 from the first position to the second position, the force urging the holder 313 toward the drive gear 311 can be increased.

[0065] That is, by driving the braking motor 323 in the direction opposite to the direction in which the braking member is moved from the first position to the second position, the rotational friction torque between the driving transmission element and the braking member can be increased.

[0066] The position of holder 313 can be moved in the thrust direction by a thrust load generated by meshing between first helical gear 314 and helical gear 321a of second helical gear 321. In addition, the load of coil spring 317 can also rotate braking motor 323 in the reverse direction. Therefore, even if the braking motor 323 is turned in the first direction to turn the brake OFF, and power to braking motor 323 is cut off, the brake can be returned to the ON state.

[0067] Cover 305 restricts the rotation range of holder 313. Restricting the rotation range of holder 313 suppresses rotation and rattle of drive gear 311, reduces backlash, and improves the accuracy of the tilt drive unit. Rotation restricting units 306 and 316 function as rotation restricting units that restrict the rotation of braking members such as seat 312 and holder 313.

[0068] During tilt drive, braking motor 323 is driven to turn the brake OFF. That is, during drive for tilt rotation by drive motor 301, the braking member is moved from the first position to the second position by brake motor 323 to turn the brake OFF. Turning the brake OFF reduces the mechanical load during tilt drive, making it possible to reduce the power consumption of drive motor 301.

[0069] The sheet 312 is a sheet member having a friction coefficient greater than a predetermined value, and the sheet 312 can provide a large friction coefficient to the sliding portion between the drive gear 311 and the holder 313. The sheet 312 and the holder 313 function as braking members for applying rotational friction torque to the drive transmission element.

[0070] By using the seat 312, it is possible to obtain a desired rotational friction torque and reduce power consumption even if the output of the braking motor 323 is reduced or the load of the coil spring 317 is reduced.

[0071] As described above, the PI unit 319 detects whether the holder 313 is in the first position or the second position, and when it is in the first position, for example, the braking motor 323 is energized (rotating in the first direction). By energizing the motor, it is possible to reduce power consumption and noise while maintaining the brake-off state.

[0072] For example, if surveillance camera 1 receives an external force while stopped at a predetermined tilt angle and attempts to change its shooting direction, the shooting direction can be maintained by increasing the power to drive motor 301 to strengthen the excitation force. As described above, a sensor is provided inside drive motor 301 as a rotation detection means for detecting the rotation angle of drive motor 301.

[0073] When the surveillance camera 1 is subjected to an external force and a slight rotation occurs, the sensor detects the change in angle and drives the drive motor 301 to return it to its original position, and the excitation force is strengthened by increasing the power to the drive motor 301. In other words, when the rotation detection means detects rotation caused by an external force on the camera unit 10, the excitation of the drive motor 301 is strengthened.

[0074] Furthermore, when the power value during excitation of drive motor 301 exceeds a certain value, braking motor 323 may be rotated in the direction opposite to the first direction to further strengthen the brake. In other words, when it is detected that a rotational torque of a predetermined value or more has been applied to camera unit 10 due to an external force, braking motor 323 may be driven in the direction opposite to the first direction to increase the rotational friction torque.

[0075] Controlling in this manner is effective in stabilizing the shooting direction when the surveillance camera 1 is exposed to a strong wind, for example.

[0076] In this embodiment, the braking mechanism is a reduction mechanism with multiple gear stages, which makes it possible to increase the braking force with less power consumption by the braking motor 323. The power required to achieve a predetermined braking force is less when rotating or exciting the braking motor 323 than when exciting the drive motor 301.

[0077] By reducing power consumption, it becomes possible to comply with the power limitations of PoE. Reducing power consumption is also cost- and environmentally friendly. The sensor that detects rotation inside the drive motor 301 functions as a rotation detection means.

[0078] As described above, according to this embodiment, it is possible to provide a surveillance camera that can maintain the tilt angle even when the drive motor 301 is not energized, and that also allows the tilt angle to be manually adjusted during installation.

[0079] 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.

[0080] 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.

[0081] (Configuration 1) A camera pan head device comprising: a drive motor for rotating a camera unit; a drive transmission mechanism including a drive transmission element for transmitting the driving force of the drive motor; a braking member for applying a rotational friction torque to the drive transmission element; an elastic member for urging the braking member to contact the drive transmission element; and a braking motor for moving the braking member from a first position in which it contacts the drive transmission element to a second position in which it does not contact the drive transmission element, wherein when the braking member is in the second position, the rotational torque applied to the braking motor by the elastic member is set to be greater than the holding torque of the braking motor when not excited.

[0082] (Configuration 2) The camera pan head device according to Configuration 1, wherein the drive transmission mechanism is rotatable by applying a force to the camera unit.

[0083] (Configuration 3) A camera pan head device as described in Configuration 1 or 2, characterized in that the center of gravity of the camera unit is offset from the rotation axis of the camera unit, and the rotational friction torque generated by contact between the drive transmission mechanism and the braking member is set to be greater than the rotational torque caused by the offset of the center of gravity of the camera unit.

[0084] (Configuration 4) A camera pan head device described in any one of configurations 1 to 3, characterized in that the rotational friction torque between the drive transmission element and the braking member is increased by driving the braking motor in a direction opposite to the direction in which the braking member is moved from the first position to the second position.

[0085] (Configuration 5) A camera pan head device as described in Configuration 4, characterized in that when it is detected that a rotational torque of a predetermined value or more has been applied to the camera unit due to an external force, the rotational friction torque is increased by driving the braking motor in the opposite direction.

[0086] (Configuration 6) A camera pan head device described in any one of configurations 1 to 5, characterized in that the braking member moves from the first position to the second position due to a thrust load generated by meshing with a helical gear rotated by the braking motor.

[0087] (Configuration 7) The camera pan head device according to any one of configurations 1 to 6, further comprising a rotation restricting portion that restricts the rotation of the braking member.

[0088] (Configuration 8) A camera pan head device according to any one of configurations 1 to 7, characterized in that when the drive motor is driven, the braking motor moves the braking member from the first position to the second position.

[0089] (Configuration 9) The camera pan head device according to any one of configurations 1 to 8, wherein the braking member has a sheet member having a coefficient of friction greater than a predetermined value.

[0090] (Configuration 10) A camera pan head device according to any one of configurations 1 to 10, characterized in that it has a detection means for detecting the position of the braking member, and when the detection means detects that the braking member has moved from the first position to the second position, it changes the braking motor from a rotating state to an excited state.

[0091] (Configuration 11) A camera pan head device according to any one of configurations 1 to 10, characterized in that it has a rotation detection means for detecting the rotation angle of the drive motor, and when the rotation detection means detects rotation due to an external force on the camera unit, it strengthens excitation of the drive motor. [Explanation of symbols]

[0092] 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 203: Drive gear 204: Coil spring 300: Motor unit 301: Drive motor 302: Drive pinion 303: Cover 305: Cover 306: Rotation control part 311: Drive gear 312: Sheet 313: Holder 314: First helical gear 315: Shielding plate 316: Rotation control part 317: Coil spring 318: Shaft 319:PI Unit 321: Second helical gear 322: Braking pinion 323: Braking motor 400: Fixed part

Claims

1. A drive motor for rotating the camera unit; a drive transmission mechanism including a drive transmission element for transmitting the drive force of the drive motor; a braking member for applying a rotational friction torque to the drive transmission element; an elastic member that biases the braking member so as to contact the drive transmission element; a braking motor for moving the braking member from a first position in contact with the drive transmission element to a second position in which the braking member is not in contact with the drive transmission element, A camera pan head device characterized in that when the braking member is in the second position, the rotational torque applied to the braking motor by the elastic member is set to be greater than the holding torque of the braking motor when it is not excited.

2. 2. The camera pan head device according to claim 1, wherein the drive 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 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. By driving the braking motor in a direction opposite to a direction in which the braking member is moved from the first position to the second position, 2. The camera pan head device according to claim 1, wherein the rotational friction torque between the drive transmission element and the braking member is increased.

5. The camera pan head device according to claim 4, characterized in that when it is detected that a rotational torque of a predetermined value or more has been applied to the camera unit due to an external force, the rotational friction torque is increased by driving the braking motor in the reverse direction.

6. 2. The camera pan head device according to claim 1, wherein the braking member moves from the first position to the second position due to a thrust load generated by meshing with a helical gear rotated by the braking motor.

7. 2. The camera pan head device according to claim 1, further comprising a rotation restricting portion that restricts rotation of the braking member.

8. 2. The camera pan head device according to claim 1, wherein the braking member is moved from the first position to the second position by the braking motor when the driving motor is driven.

9. 2. The camera pan head device according to claim 1, wherein the braking member has a sheet member having a coefficient of friction greater than a predetermined value.

10. a detection means for detecting the position of the braking member; 2. The camera pan head device according to claim 1, wherein when the detection means detects that the braking member has moved from the first position to the second position, the braking motor is changed from a rotating state to an excited state.

11. a rotation detection means for detecting a rotation angle of the drive motor; 2. The camera pan head device according to claim 1, wherein the excitation of the drive motor is strengthened when the rotation detection means detects rotation caused by an external force acting on the camera unit.

Images