JP2017204763A - Pan-tilt driving device and camera device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce backlashes of a pan-tilt driving mechanism and improve location accuracy of preset operation.SOLUTION: A pan driving device 200 comprises: a pan plate 51; a driving worm 23 supported on a substrate; a pan worm wheel 19 arranged on the substrate; a holder plate 45 parallel to the substrate; a shaft 25 rotatably supported on the holder plate 45; an intermediate worm wheel 27 fixed to one end of the shaft 25 and engaged with the driving worm 23; an intermediate worm 29 fixed to the other end of the shaft 25 and engaged with a terminal worm wheel; a slide mechanism 47 supporting the substrate in a freely slidable manner; a first coil spring 79 and a second coil spring 81 which bias the holder plate 45 toward the driving worm 23 and the terminal worm wheel; and a holder lever 49 in which one end is supported on the substrate in a freely swingable manner and the other end supports the holder plate 45 in the freely swingable manner.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a pan / tilt driving device and a camera device.

  Some camera devices include a pan / tilt driving device, and can rotate the camera body to pan and tilt so that a desired direction can be imaged. In this type of camera device, the rotation of the motor is reduced by a reduction mechanism to rotate the camera body. Some camera devices have a preset function that stores an imaging direction set by a user and automatically points the camera body in that direction. When a camera device having a preset function receives a preset instruction, it drives a motor, transmits the rotation of the motor while decelerating it by a reduction mechanism, and pans or tilts the housing that houses the camera body with respect to the camera base. Rotate, or pan and tilt and turn the camera body to the desired preset position.

  As a prior art in which the above-described reduction mechanism is applied to a camera device (for example, a monitoring camera), a reduction device with a backlash removal function described in Patent Document 1 is known. The reduction gear with a backlash removal function includes a fixed first internal gear, a rotatable second internal gear, and two satellite pair gears having a first external gear and a second external gear on the same axis. . The first external gear of the satellite pair gear meshes with the first internal gear, and the second external gear meshes with the second internal gear. A reduction ratio difference is provided in the reduction ratio between the first internal gear and the first external gear, and the reduction ratio between the second internal gear and the second external gear, and the revolution of the satellite pair gears rotates while the rotational driving force is input. Then, the rotational driving force decelerated according to the reduction ratio difference is output. At this time, the second internal gear receives torsional stress from both sides toward the gear coincidence point between the first internal gear and the second internal gear, and the backlash is removed.

JP 2007-170459 A

  However, since the speed reduction mechanism meshes a plurality of gears to transmit the rotation, the accuracy of the rotation transmission amount may decrease due to play (backlash) between the gears. In this case, there arises a problem that positioning cannot be performed with high accuracy at a preset position set in advance. When the reduction mechanism obtains a reduction ratio by meshing a pair of gears, it is relatively easy to suppress backlash. In this case, since the meshing between the gears is on the same plane, the play between the tooth surfaces can be reduced by displacing the gears in the direction within a single plane.

  However, in the case of a two-stage reduction mechanism that meshes two sets of gears to obtain a large reduction ratio, the gears may mesh on different planes. In this case, since Patent Document 1 is configured to reduce backlash by a one-stage reduction mechanism, it is difficult to simultaneously displace two sets of gears to reduce play between the tooth surfaces. Under such circumstances, there is a demand for improving the position accuracy of the preset operation even in a camera device including a two-stage reduction mechanism.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a pan / tilt driving device and a camera device that can reduce backlash of a pan / tilt driving mechanism and improve the positional accuracy of a preset operation.

  The present invention relates to a substrate, a driving worm that is rotatably supported with the center of rotation perpendicular to the substrate, and a terminal worm that is disposed to be rotatable relative to the substrate with the center of rotation perpendicular to the substrate. A wheel, a holder plate having a flat portion facing the substrate, a shaft rotatably supported with a rotation center parallel to the holder plate, and fixed to one end of the shaft and meshed with the drive worm An intermediate worm wheel, an intermediate worm fixed to the other end of the shaft and meshing with the terminal worm wheel, the substrate and the holder plate are provided, and the holder plate is parallel to the direction parallel to the substrate. A slide mechanism that is movably supported, and is provided across the substrate and the holder plate, and drives the holder plate. An urging member that urges the arm and the terminal worm wheel in a direction approaching the worm wheel, and the substrate and the holder plate. There is provided a pan / tilt drive device comprising: a holder lever that is swingably supported and that supports the holder plate at the other end in a swingable manner with a support shaft in the same direction as the swing shaft.

  In addition, the present invention includes the above-described pan / tilt driving device as a pan driving device, a pan housing that rotates about a pan rotation center with respect to a camera base, and a tilt that is orthogonal to the pan rotation center with respect to the pan housing A tilt housing that rotates about a rotation center, wherein the substrate is a pan plate that is fixed to the pan housing, and the terminal worm wheel is a pan that is fixed to the camera base. Provided is a camera device that is a worm wheel.

The perspective view of the camera apparatus of this embodiment The perspective view which looked at the camera apparatus shown in FIG. An exploded perspective view showing the pan driving device together with the camera body The perspective view which looked at the camera apparatus shown in FIG. 1 through the tilt drive device from the right rear side The disassembled perspective view which abbreviate | omitted some members of the pan drive device shown in FIG. 5 is an exploded perspective view of the main part of FIG. FIG. 3 is a plan view of the pan driving device shown in FIG. The side view which looked at the pan drive device shown in FIG. 7 from the holder plate side Cross-sectional view of the main part of the sliding mechanism in which the sliding member is a sphere Cross-sectional view of the main part of the sliding mechanism in which the sliding member is a sliding contact projection Schematic diagram explaining the reaction force acting on the shaft Side view of a holder plate according to a modification including a tilt spring Operation explanatory diagram of the pan drive device in which the intermediate worm wheel and the intermediate worm are in the design position Operation explanatory diagram of the pan driving device with the intermediate worm wheel approaching position and the intermediate worm approaching position Operation explanatory diagram of the pan drive device with the intermediate worm wheel in the separating position and the intermediate worm in the approaching position Operation explanatory diagram of pan driving device with intermediate worm wheel approaching position and intermediate worm separating position Operation explanatory diagram of the pan driving device with the intermediate worm wheel at the separation position and the intermediate worm at the separation position

  Hereinafter, an embodiment that specifically discloses a pan / tilt driving device and a camera device according to the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims. A monitoring camera will be described as an example of the camera device of the present embodiment below.

  FIG. 1 is a perspective view of the camera device of the present embodiment. FIG. 2 is a perspective view of the camera device shown in FIG. 1 as seen from the rear left side through the pan driving device. In the present embodiment, the up / down / front / rear and left / right directions follow the directions of the arrows shown in FIG.

  The surveillance camera 100 of this embodiment has a pan / tilt driving device. This pan / tilt driving device can be configured as a pan driving device 200. In addition, the pan / tilt driving device can be configured as a tilt driving device 300 (see FIG. 4). The surveillance camera 100 of this embodiment includes a pan driving device 200 as a pan / tilt driving device and a tilt driving device 300.

  First, the basic configuration of the pan / tilt mechanism of the monitoring camera 100 will be described.

  The monitoring camera 100 has a camera base 11. The camera base 11 is formed in a substantially cylindrical shape. The camera base 11 has a lower surface as an attachment surface. In the monitoring camera 100, the mounting surface of the camera base 11 is fixed to the fixed surface by a fastener such as a bolt 13.

  On the upper surface of the camera base 11, a pan axis 15 (see FIG. 2) is fixed coaxially with the axis of the camera base 11. The pan shaft 15 protrudes inside the pan housing 17 (see FIG. 1) and supports the pan housing 17 in a rotatable manner.

  The pan housing 17 is formed in a flat cylindrical shape (disk shape) having the same radius as the camera base 11. A pan worm wheel 19 is fixed to the outer periphery of the pan shaft 15 protruding into the pan housing 17. The center of the pan axis 15 is the pan rotation center Pc (see FIG. 2). That is, the pan housing 17 is supported by the camera base 11 so as to be able to rotate the pan around the pan rotation center Pc.

  FIG. 3 is an exploded perspective view showing the pan driving device together with the camera body.

  The pan housing 17 is provided with a pan motor 21 having a drive shaft protruding upward. A drive worm 23 is fixed to the drive shaft of the pan motor 21. A shaft 25 in a direction perpendicular to the pan rotation center Pc is rotatably supported by the pan housing 17 between the pan motor 21 and the pan shaft 15. An intermediate worm wheel 27 that meshes with the drive worm 23 is fixed to one end of the shaft 25. An intermediate worm 29 that meshes with the pan worm wheel 19 is fixed to the other end of the shaft 25.

  Accordingly, when the pan motor 21 is driven and the drive worm 23 transmits the rotation to the intermediate worm wheel 27 of the shaft 25, the shaft 25 rotates. By rotating the shaft 25, the intermediate worm 29 rotates around the outer periphery of the pan worm wheel 19 fixed to the camera base 11. That is, the intermediate worm 29 revolves around the pan shaft 15. As a result, the pan housing 17 is driven to rotate around the pan rotation center Pc.

  The pan housing 17 includes two sets of worm gears including the drive worm 23 and the intermediate worm wheel 27, and the intermediate worm 29 and the pan worm wheel 19, thereby preventing rotation by an external force. That is, a self-locking mechanism is provided, and it is possible to prevent the monitoring direction from being changed due to rotation of the pan housing 17 by an external force such as wind pressure.

  A pan column 31 shown in FIG. 1 stands on the upper surface of the pan housing 17 at a position outside the rotational radius from the center of the pan housing 17. The pan column 31 rotates together with the pan housing 17.

  A tilt housing 33 is provided at the standing tip of the pan column 31. The tilt housing 33 has a spherical part and accommodates the camera body 35. The tilt housing 33 is cut out at a portion (right side portion) excluding the above-described spherical portion. The standing tip of the pan column 31 is disposed at the cut portion. A tilt shaft 37 (see FIG. 4) orthogonal to the pan rotation center Pc is fixed to the side portion of the tilt housing 33. The tilt shaft 37 is supported in a rotatable state by a tilt support plate 39 fixed to the inside of the pan column 31.

  FIG. 4 is a perspective view of the camera device shown in FIG. 1 as seen from the rear right side through the tilt driving device.

  The tilt shaft 37 protrudes inside the standing tip of the pan column 31 and rotatably supports the tilt housing 33 on the standing tip. A tilt worm wheel 41 is fixed to the outer periphery of the tilt shaft 37 protruding inside the standing tip. The center of the tilt shaft 37 is the tilt rotation center Tc. That is, the tilt housing 33 is tiltable about the tilt rotation center Tc, and is supported by the tilt support plate 39 at the standing tip of the pan column 31.

  A tilt motor (not shown) having a drive shaft protruding in a direction along the tilt rotation center Tc is fixed to the standing tip of the pan column 31. A drive worm 23 is fixed to the drive shaft of the tilt motor. A shaft 25 in a direction perpendicular to the tilt rotation center Tc is rotatably supported at the standing tip of the pan column 31 between the tilt motor and the tilt worm wheel 41. An intermediate worm wheel 27 that meshes with the drive worm 23 is fixed to one end of the shaft 25. An intermediate worm 29 that meshes with the tilt worm wheel 41 is fixed to the other end of the shaft 25. Accordingly, when the tilt motor is driven and the drive worm 23 transmits the rotation to the intermediate worm wheel 27 of the shaft 25, the shaft 25 is rotated. As the shaft 25 rotates, the intermediate worm 29 rotates the tilt worm wheel 41. Accordingly, the tilt housing 33 is driven to rotate around the tilt rotation center Tc.

  The tilt housing 33 includes two sets of worm gears including the drive worm 23 and the intermediate worm wheel 27, and the intermediate worm 29 and the tilt worm wheel 41, thereby preventing rotation by an external force. That is, a self-locking mechanism is provided, and the change of the monitoring direction of the tilt housing 33 due to an external force such as wind pressure can be prevented.

  The camera body 35 includes an image sensor such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) as an imaging unit. Imaging light from the lens 43 (see FIG. 1) enters the imaging unit. The camera body 35 is disposed so that the optical axis of the lens 43 provided integrally with the camera body 35 is along the direction passing through the center of the tilt housing 33 and orthogonal to the tilt rotation center Tc.

  In the monitoring camera 100, a portion between the camera base 11 and the pan housing 17 serves as a pan rotation unit. Further, a tilt rotation part is formed between the standing tip of the pan column 31 and the tilt housing 33. Data transmission of imaging information and motor control signals in the pan rotation unit and tilt rotation unit is performed by non-contact PLC (Power Line Communication) communication using an antenna, for example. In the monitoring camera 100, power transmission in the pan rotation unit is performed by, for example, a slip ring, and power transmission in the tilt rotation unit is performed by, for example, a twist line.

  In the surveillance camera 100, the pan rotation unit and the tilt rotation unit have a watertight structure. The pan rotation part and the tilt rotation part constitute a waterproof structure in which the gap between the shaft and the bearing is closed by a waterproof sealing material that contacts both. Thereby, the surveillance camera 100 can be made outdoor specifications without being covered with the dome cover.

  Next, the pan / tilt driving device will be described.

  The pan / tilt driving device can be used for both the pan driving device 200 and the tilt driving device 300. The surveillance camera 100 according to the present embodiment includes both a pan driving device 200 and a tilt driving device 300. The monitoring camera 100 may include one of the pan driving device 200 and the tilt driving device 300. The pan driving device 200 and the tilt driving device 300 have substantially the same configuration. Therefore, in the following description, the pan driving apparatus 200 will be mainly described as a representative example.

  The pan / tilt driving device includes a substrate, a driving worm 23, a terminal worm wheel (pan worm wheel 19, tilt worm wheel 41), a holder plate 45, a shaft 25, an intermediate worm wheel 27, an intermediate worm 29, and a slide. A mechanism 47 (see FIG. 3), an urging member, and a holder lever 49 are included.

  FIG. 5 is a perspective view in which some members of the pan driving device are omitted.

  The surveillance camera 100 includes a pan / tilt driving device as the pan driving device 200. In the pan driving device 200, the substrate is a pan plate 51 fixed to the pan housing 17. The terminal worm wheel is a pan worm wheel 19 fixed to the camera base 11. The pan plate 51 is fixed to the pan housing 17. The pan plate 51 is formed with a pair of spaced apart first spring receiving pins 53 erected on the opposite side of the shaft 25 across the pan worm wheel 19.

  The drive worm 23 is rotatably supported by the pan plate 51 with the rotation center being vertical. A pan motor 21 is fixed to the lower surface of the pan plate 51. The drive shaft of the pan motor 21 penetrates the pan plate 51 upward. The drive worm 23 is fixed to a drive shaft that penetrates the pan plate 51.

  The pan worm wheel 19 is disposed so as to be rotatable relative to the pan plate 51 with the center of rotation perpendicular to the pan plate 51. Here, the relative rotation means that the pan plate 51 rotates with respect to the fixed pan worm wheel 19. As a result, the pan plate 51 revolves with respect to the pan worm wheel 19.

  The holder plate 45 is formed to be long at a distance larger than the distance between the pan worm wheel 19 and the drive worm 23. The holder plate 45 is disposed parallel to the pan plate 51. The holder plate 45 has a flat portion facing the substrate. The holder plate 45 has a plurality (four in the present embodiment) of spherical housing parts 55 (see FIG. 5) that protrudes on the side opposite to the pan plate 51. The spherical body accommodating portion 55 becomes a part of the slide mechanism 47. Further, the holder plate 45 has a pair of first spring fixing pieces 57 on both end sides extending across the pan worm wheel 19.

  The shaft 25 has a center of rotation parallel to the holder plate 45 and is rotatably supported at both ends. Both ends of the shaft 25 are supported by side walls at both ends in the longitudinal direction of the holder plate 45 through, for example, ball bearings 59.

  The intermediate worm wheel 27 that meshes with the drive worm 23 is fixed to one end of the shaft 25.

  The intermediate worm 29 that meshes with the pan worm wheel 19 is fixed to the other end of the shaft 25.

  6 is an exploded perspective view of the main part of FIG. The holder plate 45 is formed by integrally fixing a first holder 61 and a second holder 63 with a plurality of holder connecting screws 65. The first holder 61 supports the end of the shaft 25 on the side where the intermediate worm 29 is provided via a ball bearing 59. The second holder 63 supports the end of the shaft 25 on the side where the intermediate worm wheel 27 is provided via a ball bearing 59. The holder plate 45 has such a divided structure to facilitate press molding and facilitate the assembly of the shaft 25.

  The holder plate 45 has a second spring fixing piece 67 in the first holder 61. On the pan plate 51, a second spring receiving pin 69 (see FIG. 3) stands on the opposite side of the intermediate worm 29 with the second spring fixing piece 67 interposed therebetween.

  FIG. 7 is a plan view of the pan driving apparatus shown in FIG. FIG. 8 is a side view of the pan driving device shown in FIG. 7 as viewed from the holder plate side.

  The slide mechanism 47 is provided across the pan plate 51 and the holder plate 45 with a sliding member interposed therebetween. The slide mechanism 47 supports the holder plate 45 so as to be movable in a direction parallel to the surface of the pan plate 51. In the present embodiment, the slide mechanism 47 is provided at a total of four locations, one on each end of the holder plate 45, one on the holder plate 45 near the center of the shaft 25, and one on the holder plate 45 near the intermediate worm 29. Be placed. The number of slide mechanisms 47 is not limited to this. These slide mechanisms 47 are arranged evenly and discretely on the lower surface of the holder plate 45. That is, the slide mechanism 47 is arranged so that the respective shared loads are substantially the same.

  FIG. 9 is a cross-sectional view of a main part of a slide mechanism in which the sliding member is a sphere. The slide mechanism 47 accommodates the sphere 71 on the lower surface side of the sphere accommodating portion 55 in the present embodiment. The sphere 71 comes into contact with the pan plate 51 so as to be rotatable inside the sphere housing portion 55. Therefore, the holder plate 45 is slidable with low friction when the four spheres 71 come into point contact, and is lifted from the pan plate 51. Thus, the slide mechanism 47 supports the holder plate 45 on the pan plate 51 in a direction parallel to the surface of the pan plate 51 so as to be slidable with low friction.

  According to the slide mechanism 47 having the sphere 71, the holder plate 45 can be slidably supported on the pan plate 51 and the tilt support plate 39 with low friction due to point contact.

  FIG. 10 is a cross-sectional view of the main part of the sliding mechanism in which the sliding member is a sliding contact protrusion. The slide mechanism 47 may support the holder plate 45 on the pan plate 51 so as to be slidable by using another sliding member. As another sliding member, the sliding contact protrusion 73 is mentioned, for example. The sliding contact projection 73 fixes the leg portion to the pan plate 51, applies a lubricant such as grease 75 to the sliding contact surface, and supports the holder plate 45 to the pan plate 51 slidably with low friction.

  According to the slide mechanism 47 having the sliding contact projection 73, the sliding contact projection 73 can be fixed to the pan plate 51 and the tilt support plate 39 in advance, so that the assembly of the slide mechanism 47 can be facilitated.

  In addition, the sliding member provided in the slide mechanism 47 may be a roller.

  The slidable holder plate 45 is pushed down by the pan plate 51 by a plurality of hold-down devices 77. The holddown device 77 includes a holddown bolt and a holddown spring. The tip of the hold down bolt passes through the holder plate 45 and is screwed to the pan plate 51. The hold down spring is disposed in a compressed state between the head of the hold down bolt and the holder plate 45. Thereby, the holder plate 45 is held by the hold-down spring in a pressed state on the pan plate 51.

  The biasing member is made of, for example, a coil spring. In the present embodiment, the coil spring includes a first coil spring 79 and a second coil spring 81. The first coil spring 79 and the second coil spring 81 are provided across the pan plate 51 and the holder plate 45. The first coil spring 79 is stretched between the first spring receiving pin 53 of the pan plate 51 and the first spring fixing piece 57 of the holder plate 45. The first coil spring 79 serves as a tension spring. The first coil spring 79 biases the holder plate 45 in a direction approaching the drive worm 23 and the pan worm wheel 19 (that is, applies a preload).

  The second coil spring 81 is stretched between the second spring receiving pin 69 of the pan plate 51 and the second spring fixing piece 67 of the holder plate 45. The second coil spring 81 serves as a tension spring. The second coil spring 81 urges the holder plate 45 in the direction along the shaft 25 (that is, applies a preload) to the side where the drive worm 23 is provided.

  The holder lever 49 is disposed between the pan plate 51 and the holder plate 45 in parallel with the surface of the pan plate 51. The holder lever 49 is formed of a plate-like plate by, for example, pressing. The holder lever 49 is swingably supported by the pan plate 51 via a swing shaft 83 whose one end is perpendicular to the pan plate 51. The holder lever 49 rotatably supports the holder plate 45 with a support shaft 85 at the other end. That is, the holder plate 45 can swing around the swing shaft 83 by the holder lever 49 and can rotate around the support shaft 85.

  As a result, the holder lever 49 moves both or one of the intermediate worm wheel 27 and the intermediate worm 29 provided at both ends of the shaft 25 to the drive worm 23 and the pan worm wheel 19 (or the tilt worm wheel 41). It can be movably supported in the direction of approaching and moving away.

  The stopper 87 includes a plurality of (three in this embodiment) standing claws 89 shown in FIG. 5 and the same number of restriction holes 91 shown in FIG. The standing claws 89 are formed to stand vertically from the pan plate 51 by cutting and raising the pan plate 51, for example. The restriction hole 91 is formed in the holder plate 45 as a square hole, and the standing claw 89 is inserted inward. The standing claw 89 has a notch 93. The notch 93 receives (that is, engages) the edge of the restriction hole 91. The holder plate 45 is restricted from being lifted above a certain level from the pan plate 51 by engaging the notch 93 with the notch 93 of the standing claw 89. The standing claw 89 and the restriction hole 91 can be moved relative to each other within a range in which the standing claw 89 can move inside the restriction hole 91. Thereby, the holder plate 45 is restricted by the stopper 87 from being moved in parallel with the pan plate 51 by a predetermined amount or more.

  FIG. 11 is a schematic diagram for explaining the reaction force acting on the shaft. The intermediate worm wheel 27 and the intermediate worm 29 fixed to the shaft 25 receive reaction force from the drive worm 23 and the pan worm wheel 19 when the rotational force from the pan motor 21 is transmitted. This reaction force is in the direction of reaction force A, reaction force B, and reaction force C indicated by arrows in FIG. In the pan / tilt driving device, the reaction force A is supported by the hold-down device 77 and the sphere 71 of the slide mechanism 47. The reaction force B is supported by the first coil spring 79 and the stopper 87. The reaction force C is supported by the second coil spring 81 and the holder lever 49.

  FIG. 12 is a side view of a holder plate according to a modification including a tilt spring. The holder plate 45 may stretch an inclined spring 95 between the pan plate 51 and the holder plate 45. The inclined spring 95 becomes a tension spring. The inclined spring 95 is stretched while being inclined with respect to the vertical direction of the pan plate 51. Due to this inclination, the inclination spring 95 has a preload (component force F1) in a direction in which the holder plate 45 approaches the drive worm 23 and the pan worm wheel 19, and a preload (component force in a direction in which the holder plate 45 approaches the pan plate 51). F2) can be generated.

  The pan / tilt driving device can simplify the preload structure by disposing part or all of the first coil spring 79 and the hold-down device 77 by providing the tilt spring 95.

  The surveillance camera 100 can also include a pan / tilt driving device as a tilt driving device 300 as shown in FIG. In the tilt driving device 300, the substrate is a tilt support plate 39 that is supported by the pan column 31 of the pan housing 17. The terminal worm wheel is a tilt worm wheel 41 fixed to a tilt shaft 37 that rotates integrally with the tilt housing 33.

  In the tilt driving device 300, a tilt motor (not shown) is fixed to the tilt support plate 39. The drive shaft of the tilt motor passes through the tilt support plate 39. The drive shaft of the tilt motor passes through the tilt support plate 39 in the same direction as the tilt shaft 37. The drive worm 23 is fixed to the drive shaft of the tilt motor that passes through the tilt support plate 39. Other configurations of the tilt driving device 300 are the same as those of the pan driving device 200.

  Next, the operation of the pan / tilt driving device will be described using the pan driving device 200 as a representative example.

  FIG. 13 is an operation explanatory diagram of the pan driving device in which the intermediate worm wheel and the intermediate worm are in the design position. In the pan driving device 200, when the drive worm 23 is not driven, the intermediate worm wheel 27 and the intermediate worm 29 are arranged at a design position where the worm wheel 27 and the intermediate worm 29 are not displaced (a predetermined relative position with respect to the drive worm 23 and the terminal worm wheel).

  FIG. 14 is an operation explanatory diagram of the pan driving device in which the intermediate worm wheel is in the approach position and the intermediate worm is in the approach position. When the reaction force from the drive worm 23 and the pan worm wheel 19 is smaller than the urging force of the first coil spring 79 and the second coil spring 81, the pan drive device 200 includes the intermediate worm wheel 27 and the intermediate worm 29. And displace in a direction approaching the pan worm wheel 19.

  FIG. 15 is an operation explanatory diagram of the pan driving device in which the intermediate worm wheel is in the separation position and the intermediate worm is in the approaching position. In the pan driving device 200, the reaction force from the drive worm 23 is larger than the urging force of the first coil spring 79 and the second coil spring 81, and the reaction force from the pan worm wheel 19 is the force of the first coil spring 79 and the second coil spring 81. When the force is smaller than the urging force, the intermediate worm wheel 27 is separated from the drive worm 23 and the intermediate worm 29 is displaced in a direction approaching the pan worm wheel 19.

  FIG. 16 is an operation explanatory view of the pan driving device in which the intermediate worm wheel is in the approach position and the intermediate worm is in the separation position. In the pan driving device 200, the reaction force from the drive worm 23 is smaller than the biasing force of the first coil spring 79 and the second coil spring 81, and the reaction force from the pan worm wheel 19 is the force of the first coil spring 79 and the second coil spring 81. If it is greater than the urging force, the intermediate worm wheel 27 approaches the drive worm 23 and the intermediate worm 29 is displaced away from the pan worm wheel 19.

  FIG. 17 is an explanatory view of the operation of the pan driving device in which the intermediate worm wheel is at the separation position and the intermediate worm is at the separation position. When the reaction force from the drive worm 23 and the pan worm wheel 19 is larger than the urging force of the first coil spring 79 and the second coil spring 81, the pan drive device 200 includes the intermediate worm wheel 27 and the intermediate worm 29. And displace in a direction away from the pan worm wheel 19.

  Next, the operation of the above-described pan / tilt driving device according to the present embodiment will be described.

  In the pan / tilt drive device of the present embodiment, the drive worm 23 and the pan worm wheel 19 are rotatably disposed on the pan plate 51 in a direction in which the center of rotation is perpendicular to the pan plate 51. The drive worm 23 is fixed to the drive shaft of the pan motor 21. The pan plate 51 is provided with a holder plate 45 in parallel. The holder plate 45 rotatably supports the shaft 25 parallel to the holder plate 45. The shaft 25 fixes an intermediate worm wheel 27 at one end. The intermediate worm wheel 27 meshes with the drive worm 23. Therefore, when the pan motor 21 is driven, the intermediate worm wheel 27 is rotated by the drive worm 23, and the shaft 25 is integrally rotated. An intermediate worm 29 is fixed to the other end of the shaft 25. The shaft 25 rotates integrally with the intermediate worm 29 by rotating. The intermediate worm 29 meshes with the pan worm wheel 19.

  Here, the pan worm wheel 19 is fixed to the camera base 11. In the case of the pan driving device 200, the pan plate 51 revolves around the outer periphery of the pan worm wheel 19 together with the holder plate 45 when the intermediate worm 29 rotates.

  On the other hand, in the case of the tilt driving device 300, when the intermediate worm 29 rotates, the tilt worm wheel 41 rotates. The intermediate worm wheel 27 is fixed to the tilt shaft 37. As a result, the tilt housing 33 supported by the tilt shaft 37 rotates.

  These operations are a result of the rotation of the drive worm 23 being transmitted to the pan worm wheel 19 and the tilt worm wheel 41 via the intermediate worm wheel 27 and the intermediate worm 29 fixed to both ends of the shaft 25.

  The drive worm 23 and the intermediate worm wheel 27 constitute a first-stage reduction mechanism. The intermediate worm 29 and the terminal worm wheel (the pan worm wheel 19 or the tilt worm wheel 41) constitute a second-stage reduction mechanism. In other words, the pan / tilt drive device has two speed reduction mechanisms.

  There is a backlash between the drive worm 23 and the intermediate worm wheel 27. Further, backlash also exists between the intermediate worm 29 and the terminal worm wheel (the pan worm wheel 19 or the tilt worm wheel 41). Backlash is play between tooth surfaces when a pair of gears are engaged. If the backlash is too large, the rotation transmission mechanism reduces the accuracy of transmission of the rotation amount, and cannot be directed in the correct direction when the camera device is driven in the imaging direction set by the preset function. The play between the tooth surfaces can be suppressed by holding the gears close to each other.

  However, in a rotation transmission mechanism in which the speed reduction mechanism is provided in two stages, it may be difficult to simultaneously bring the gears meshed at two locations close together. For example, the drive worm 23 and the intermediate worm wheel 27 are engaged with each other, and the intermediate worm 29 and the terminal worm wheel (the pan worm wheel 19 or the tilt worm wheel 41) are engaged with each other. In such a multi-stage rotation transmission mechanism, the point where the drive worm 23 and the intermediate worm wheel 27 mesh with each other and the point where the intermediate worm 29 and the terminal worm wheel mesh with each other are located on different planes. For this reason, it is necessary to press the intermediate worm wheel 27 at one end of the shaft 25 and the intermediate worm 29 at the other end of the shaft 25 simultaneously against the drive worm 23 and the terminal worm wheel.

  On the other hand, the pan / tilt drive device needs to protect the gear transmission mechanism by allowing displacement due to a reaction force at the time of overload such as the start of driving.

  Therefore, in the present embodiment, the pan / tilt drive device (pan drive device 200, tilt drive device 300) includes a holder plate 45 that supports the shaft 25 and a substrate (pan plate 51, tilt support) by a slide mechanism 47 and a holder lever 49. Supported by the plate 39). The shaft 25 can be displaced by the slide mechanism 47 and the holder lever 49. As a result, the pan / tilt drive device causes the intermediate worm wheel 27 at one end of the shaft 25 and the intermediate worm 29 at the other end of the shaft 25 to simultaneously drive the worm 23 and the terminal worm wheel (that is, the pan worm wheel 19). Can be pressed against.

  Further, in the event of an overload due to reaction force, the holder plate 45 is displaced against the biasing force of the first coil spring 79 and the second coil spring 81 by the holder lever 49 within the allowable range of the stopper 87 to protect the gear transmission mechanism. can do.

  As a result, the pan / tilt driving device is provided with two speed reduction mechanisms and the gears are located on different planes. A decrease in transmission accuracy can be suppressed. That is, during normal operation, the surveillance camera 100 is transmitted to the intermediate worm wheel 27 with high accuracy while the rotation of the drive worm 23 is decelerated by the pan drive device 200 at a large reduction ratio.

  Further, in the monitoring camera 100, in the two-stage reduction mechanism in which the rotation is transmitted from the drive worm 23 to the tilt worm wheel 41, a decrease in transmission accuracy of the tilt rotation amount is suppressed. That is, the surveillance camera 100 is transmitted to the tilt worm wheel 41 with high accuracy while the rotation of the drive worm 23 is decelerated by the tilt drive device 300 with a large reduction ratio.

  In the surveillance camera 100, both the pan driving device 200 and the tilt driving device 300 described above suppress a decrease in pan rotation amount transmission accuracy and a tilt rotation amount transmission accuracy. In other words, the surveillance camera 100 is highly accurate to the pan worm wheel 19 and the tilt worm wheel 41 while the rotation of the drive worm 23 is decelerated at a large reduction ratio in each of the pan driving device 200 and the tilt driving device 300. Is transmitted to.

  While various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the above configuration example, the case where the gear meshed with the worm is a worm wheel has been described. However, in the configuration of the present invention, the gear meshed with the worm can be a helical gear or a screw gear. Moreover, although the case where the surveillance camera includes two pan driving devices and a tilt driving device as a pan / tilt driving device has been described, the configuration of the present invention may include either a pan driving device or a tilt driving device. Good.

  Therefore, according to the pan driving device 200 and the tilt driving device 300 which are the pan / tilt driving devices of the present embodiment, in order to increase the reduction ratio, one set of worms and worm wheels and another set of worms and worm wheels are provided. Also in the two-stage reduction mechanism provided, backlash can be reduced.

  According to the monitoring camera 100 of the present embodiment, the backlash of the pan driving device 200 and the backlash of the tilt driving device 300 can be reduced, and the position accuracy of the preset operation can be improved. In addition, since the surveillance camera 100 can reduce backlash, when the correction for vibration caused by wind or the like (so-called camera shake correction) is performed, the play of the deceleration mechanism is reduced, so that the follow-up capability of the correction function is improved. Can be increased.

11 Camera base 17 Pan housing 19 Pan worm wheel (terminal worm wheel)
23 Drive worm 25 Shaft 27 Intermediate worm wheel 29 Intermediate worm 33 Tilt housing 37 Tilt shaft 39 Tilt support plate (substrate)
41 Tilt worm wheel (terminal worm wheel)
45 Holder plate 47 Slide mechanism 49 Holder lever 51 Pan plate (substrate)
71 Spherical body 73 Sliding contact projection 79 First coil spring (biasing member)
81 Second coil spring (biasing member)
83 Oscillating shaft 85 Support shaft 87 Stopper 95 Tilt spring 100 Monitoring camera 200 Pan driving device 300 Tilt driving device Tc Tilt rotation center Pc Pan rotation center

Claims (8)

A substrate,
A drive worm that is rotatably supported with the center of rotation perpendicular to the substrate;
A terminal worm wheel that is disposed so that the center of rotation is perpendicular to the substrate and is rotatable relative to the substrate;
A holder plate having a flat portion facing the substrate;
A shaft that is rotatably supported with the center of rotation parallel to the holder plate;
An intermediate worm wheel fixed to one end of the shaft and meshing with the drive worm;
An intermediate worm fixed to the other end of the shaft and meshing with the terminal worm wheel;
A slide mechanism which is provided across the substrate and the holder plate and supports the holder plate in a direction parallel to the substrate so as to be movable in parallel;
A biasing member provided across the substrate and the holder plate and biasing the holder plate in a direction approaching the drive worm and the terminal worm wheel;
The substrate is disposed between the substrate and the holder plate in parallel with the substrate, and one end is supported to be swingable via a swing shaft perpendicular to the substrate, and the other end of the holder plate is connected to the swing shaft. A holder lever that is swingably supported by a support shaft in the same direction,
Pan / tilt drive. The pan / tilt driving device according to claim 1,
The urging member is stretched between the substrate and the holder plate to urge the holder plate in a direction approaching the driving worm and the terminal worm wheel, and urging the holder plate in a direction approaching the substrate. Is an inclined spring,
Pan / tilt drive. The pan / tilt driving device according to claim 1,
The slide mechanism has a sliding contact protrusion that is sandwiched between the substrate and the holder plate.
Pan / tilt drive. The pan / tilt driving device according to claim 1,
The slide mechanism has a sphere sandwiched between the substrate and the holder plate;
Pan / tilt drive. The pan / tilt driving device according to claim 1,
A stopper is provided on the substrate for restricting the holder plate from separating from the driving worm and the terminal worm wheel by a predetermined distance or more.
Pan / tilt drive. A pan-tilt drive device according to any one of claims 1 to 5;
A pan housing that rotates around the center of pan rotation relative to the camera base;
A tilt housing that rotates about a tilt rotation center that is orthogonal to the pan rotation center with respect to the pan housing;
The substrate is a pan plate fixed to the pan housing;
The terminal worm wheel is a pan worm wheel fixed to the camera base;
Camera device. A pan-tilt drive device according to any one of claims 1 to 5;
A pan housing that rotates around the center of pan rotation relative to the camera base;
A tilt housing that rotates about a tilt rotation center that is orthogonal to the pan rotation center with respect to the pan housing;
The substrate is a tilt support plate supported by the pan housing;
The terminal worm wheel is a tilt worm wheel fixed to a tilt shaft that rotates integrally with the tilt housing;
Camera device. Two pan-tilt drive devices according to any one of claims 1 to 5, each having a pan drive device and a tilt drive device,
A pan housing that rotates around the center of pan rotation relative to the camera base;
A tilt housing that rotates about a tilt rotation center orthogonal to the pan rotation center with respect to the pan housing,
The pan driving device
The substrate is a pan plate fixed to the pan housing;
The terminal worm wheel is a pan worm wheel fixed to the camera base;
The tilt driving device includes:
The substrate is a tilt support plate supported by the pan housing;
The terminal worm wheel is a tilt worm wheel fixed to a tilt shaft that rotates integrally with the tilt housing;
Camera device.

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