JP2019102906A - Imaging apparatus - Google Patents

Abstract

To provide an imaging apparatus comprising multiple cameras and a PTZ camera, capable of realizing high stop position accuracy, even when installed under severe environment where the environmental temperature varies significantly.SOLUTION: An imaging apparatus includes multiple fixed cameras arranged circularly, a pan-tilt camera placed substantially at the center of the multiple cameras, and capable of pan-tilt, a control board for controlling at least the pan-tilt camera, rotation detection means for detecting the pan rotation angle or the tilt rotation angle of the pan-tilt camera, and walls provided between the multiple fixed cameras and the rotation detection means, and between the control board and the rotation detection means. The rotation detection means is isolated from the multiple fixed cameras and the control board by means of the walls.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an imaging device provided with a plurality of cameras.

  Surveillance cameras are used for the purpose of crime prevention and disaster prevention in office buildings, shops, and downtown areas. The user selects and installs a camera according to the intended use. For example, an omnidirectional camera with a wide angle of view may be installed when it is desired to perform overhead monitoring, and a pan-tilt camera (hereinafter referred to as a PTZ camera) with an optical zoom may be installed when it is desired to acquire an enlarged image.

  In addition, when a suspicious object or a suspicious person is found in the site while comprehensively monitoring a large site, the monitoring application to obtain an image in which the location is enlarged, the wide range is omnidirectional Shoot with the camera. Then, a PTZ camera may be used to zoom in on a suspicious object or a suspicious person appearing in the image of the omnidirectional camera by linking the cameras to each other. As a camera suitable for such an application, as disclosed in Patent Document 1, a multi-view camera capable of acquiring a high resolution image by arranging a plurality of cameras circumferentially is well known. Some PTZ cameras are disposed near the center of the multi-view camera in order to obtain a more detailed image in the omnidirectional image captured by the multi-view camera. Such a PTZ camera is often used to zoom the face of a person who has acquired an omnidirectional image, for example. Therefore, a high magnification zoom is often mounted, and high stop position accuracy is required for pan and tilt. .

Patent No. 5925868 Public Relations

  In the configuration of Patent Document 1, when the PTZ camera is disposed in the vicinity of the central portion, it is considered that the pan and tilt stop position accuracy is sufficient for general monitoring purposes. However, in the method of using the multi-view camera and the PTZ camera in cooperation with each other, as described above, higher stop position accuracy is required. In particular, on the tele side of a high magnification zoom PTZ camera, the angle of view may be about 1 ° to 2 °. Therefore, in a configuration using a normal stepping motor and using a gear, a belt or the like as a drive transmission means, there is a possibility that desired accuracy can not be obtained due to backlash of the gear, backlash of the belt or the like.

  In addition, there are various environments in which an imaging device including a multi-view camera and a PTZ camera is installed, for example, it may be installed outdoors, and under such an environment, the temperature difference between day and night is very large. There is also. If the temperature difference in the environment is large, the desired stop position accuracy may not be obtained even by expansion or contraction of the drive transmission means such as a gear.

  Therefore, it is an object of the present invention to realize high-accuracy stop position accuracy even when installed in a severe environment where the environmental temperature fluctuates significantly in an imaging device including a plurality of cameras and a PTZ camera. An object of the present invention is to provide an imaging device.

An imaging apparatus according to the present invention includes: a plurality of fixed cameras arranged in a circumferential shape; a pan and tilt camera arranged substantially at the center of the plurality of cameras and capable of pan and tilt; and a control board for controlling at least the pan and tilt camera.
Rotation detection means for detecting a pan rotation angle or a tilt rotation angle of the pan and tilt camera;
And a wall provided between the plurality of fixed cameras and the rotation detection means, and between the control board and the rotation detection means, the rotation detection means comprising the wall by the wall It is characterized by being isolated from a plurality of fixed cameras and the control board.

  According to the present invention, in an imaging apparatus including a plurality of cameras and a PTZ camera, high accuracy stop position accuracy can be realized even when installed under a severe environment where the environmental temperature fluctuates significantly. it can.

FIG. 1 is an external perspective view of a multi-view camera 1; FIG. 2 is a view showing the inside of the multi-view camera 1; FIG. 1 is a cross-sectional view of a multi-view camera 1; It is the enlarged view to which the encoder periphery was expanded. It is sectional drawing of the multiview camera 1 of 2nd Example. It is a figure which shows the inside of the multiview camera 1 of 3rd Example. It is BB sectional drawing of FIG.

Example 1
Embodiments of the present invention will be described in detail with reference to FIGS.

  FIG. 1 is an external perspective view of the multi-view camera 1. The exterior is configured of a bottom cover 204 and a transparent cover 205 for attaching the multi-view camera 1 to a ceiling or the like. When the transparent cover 205 is removed, as shown in FIG. 2, six fixed cameras 101 to 106 arranged in a substantially circular shape are fixed to the base 201 as a wall, and further near the central portion (approximately the center) The pan tilt camera 107 is fixed. The fixed cameras 101 to 106 each have an imaging sensor (not shown) and an optical system (not shown), and are fixed so as to be able to capture the outside of the multiview camera 1. The images obtained by the fixed cameras 101 to 106 are subjected to image processing by the control substrate 202 fixed to the base 201, and the images are connected and output as a panoramic image.

  The pan and tilt camera 107 can pan and tilt the camera unit 203 as an imaging unit having an imaging sensor (not shown) and a zoomable optical system (not shown). The panoramic image obtained by the fixed cameras 101 to 106 is confirmed by a personal computer connected to a multi-view camera and a network, and the user further specifies an area for which a detailed image is to be acquired. Zoom in and shoot. As described above, when coordinates are formed by the panoramic image and zooming toward the coordinates, if the pan / tilt positioning accuracy is not sufficient, a zoom image of a desired area can not be acquired, so high pan / tilt positioning accuracy is required. The control method and the like are well-known techniques and thus the details thereof will be omitted.

  A control board 202 for processing an image and supplying power to each device such as a driving means is fixed to the base 201, and electrical connection means (not shown) for the fixed cameras 101 to 106 and the pan and tilt camera 107. Are electrically connected. The base 201 is desirably a material with good thermal conductivity such as aluminum also for dissipating the heat of the control substrate 202, but it may be a resin depending on the power consumption and the necessary heat dissipation capability. A bottom cover 204 as a part of a housing is disposed outside the control substrate 202 so as to cover the control substrate 202.

  A transparent cover 205 made of polycarbonate (PC) is disposed on the subject side of the fixed cameras 101 to 106 and the pan and tilt camera 107 for protecting the cameras. The transparent cover 205 is fixed to the bottom cover 204 by fastening means (not shown) such as screws.

  Generally, multi-lens cameras are often used for the purpose of monitoring a large site, and therefore it is required to be able to be installed outdoors. Since it is necessary to prevent water from entering the inside of the main body in order to use it outdoors, the bottom cover 204 and the transparent cover 205 in this embodiment also have a structure sealed by rubber packing (not shown). The structure is omitted.

  Next, the pan driving of the pan and tilt camera 107 will be described in detail with reference to FIGS.

  A pan base 206 as a pan supporting unit made of resin is fixed to the base 201 by screws (not shown). The pan gear 207 is fixed to the pan base 206, and the drive of the stepping motor 213 fixed to the tilt base 209 as the tilt supporting means is transmitted through the pan belt 208 and pan rotation is performed at a desired number of rotations. The pan base 206 supports the tilt base 209 in a pan rotatable manner. In addition, the tilt base 209 supports the camera unit in a tiltable manner. As described above, the stop accuracy of the pan and tilt camera 107 is required to be high. Therefore, in the present embodiment, control is performed to a desired stop position accuracy using the optical encoder 212 as the rotation detection means. The optical encoder 212 includes an encoder scale 210 and an encoder sensor 211 as an example of a light emitting element and a light receiving element. The optical encoder 212 detects light reflected by the encoder scale 210 with the encoder sensor 211 and detects the position, but this is a known technique, and thus the details will be omitted. Next, the arrangement of the optical encoder 212 will be described using the cross-sectional perspective view of FIG. 4. The encoder sensor 211 is fixed on the surface of the pan gear 207, and the encoder scale 210 is disposed on the surface of the tilt base 209 opposed to the pan gear 207 to detect the pan rotation angle. The detected pan rotation angle is fed back to the control board 202 to control the pan rotation angle. The optical encoder 212 is separated from the plurality of fixed cameras 101 to 106 and the control board 202 by the base 201.

  As an encoder scale, a method of etching or printing a pattern on glass or resin is well known. However, in the case of using a method of printing on a commonly used resin surface, the pitch of the printed pattern is also changed due to the expansion and contraction of the resin, and as a result, the stop position is also shifted by the contraction. It is well known that the resin has a property of being easily shrunk by temperature, and when the resin encoder scale is used, the stop position changes sensitively to the temperature of the space in which the encoder scale is disposed.

  By the way, in the multi-view camera 1 as in the present embodiment, in addition to obtaining images by the plurality of fixed cameras 101 to 106, power supply to each device such as the stepping motor 213 is required, and thus a control board 202 requires a large amount of power. Since part of the power is converted to heat, the control substrate 202 generates a large amount of heat.

  Further, in the multi-view camera 1 using the plurality of fixed cameras 101 to 106 as in the present embodiment, the image sensors are also arranged in the same number as the fixed cameras, which can be a heat generation source generating large heat.

  As described above, the encoder scale 210 is sensitive to temperature, and the heat causes the encoder scale 210 to expand when the encoder scale 210 is placed in the vicinity of a heat source that generates a large amount of heat. The stop position accuracy is controlled by the step angle rotated by the stepping motor 213 and the angle obtained by the optical encoder 212 as a rotation detection means. However, if the angle obtained by the optical encoder 212 shifts, the stop position shifts by the shifted angle.

  In order to reduce such deviation, in the present embodiment, as shown in FIG. 3 and FIG. A pan base 206 is arranged. By so doing, by sticking the encoder scale 210 on the surface of the pan gear 207 fixed to the pan base 206, the heat of the control substrate 202 is not easily transmitted to the encoder scale 210.

  Furthermore, as described above, since the imaging sensors of the fixed cameras 101 to 106 can also be sources of large heat, the pan base 206 is disposed via the air layer 300 with respect to the base 201 to which the fixed cameras 101 to 106 are fixed. doing. By doing this, the heat of the imaging sensors of the fixed cameras 101 to 106 is hard to be transmitted to the encoder scale 210.

  In the present embodiment, the encoder scale 210 is disposed via the air layer 300 with respect to the control substrate 202 as a heat source and the base 201 to which heat is easily transmitted from the fixed cameras 101 to 106. The encoder sensor 211 is further disposed via the air layer 301, and thermally shuts off the optical encoder 212 as a rotation detection unit configured by the encoder scale 210 and the encoder sensor 211 from the control substrate 202 as a heat source. It was set up.

  In the present embodiment, the pan base 206 is made of resin, but if the pasting portion of the encoder scale 210 is sufficiently far from the fixing portion of the base 201 and the pan base 206 and it is considered as being thermally interrupted. The pan base 206 may be made of metal. In addition, the effect is not changed even if a configuration in which the resin base spacer is interposed between the fixing surfaces of the pan base 206 and the base 201 to thermally shut off.

  Although the encoder scale 210 is arranged on the tilt base 209, the effect is not changed even if it is arranged on the pan base 206.

  Although the control substrate 202 is configured of one sheet, the same effect can be obtained by adopting a configuration in which the control substrate 202 is divided into two pieces and the heat is similarly cut off.

Example 2
In the above-described embodiment, the optical encoder 212 as the rotation detecting means is disposed in the space thermally shut off with respect to the heat source, so as to realize high-precision stop position accuracy. However, in the case where the heat source is forcibly cooled by the fan, by arranging the rotation detection means in the space cut off from the air path, it is possible to realize the high accuracy positioning accuracy as in the above embodiment. .

  FIG. 5 is a multi-view camera with a pan-tilt camera equipped with a centrifugal fan as an example of a pan drive fan for forcibly cooling the control substrate 403 as an example of a pan control substrate. The configurations of the multi-view camera and the pan-tilt camera are omitted because they are the same as those of the above-described embodiment.

  The centrifugal fan A 401 is fixed to the base 406 with a screw (not shown), and sends the air warmed by the control substrate 403 to a space near the tilt portion of the pan and tilt camera 107 which is relatively cool in the main body. The wind is sent in a flow path like an arrow. The air cooled in the space near the tilt portion is sent again to the space where the control board 403 is disposed by the centrifugal fan B402. The control substrate 403 is cooled through the flow path formed in this manner.

  On the other hand, the pan gear B 404 is fixed to a pan base B 405 made of resin, and the base 406 to which the heat of the control substrate 403 is transmitted is thermally shut off similarly to the above embodiment. Furthermore, since the encoder scale 407 is disposed on the surface of the pan gear 207, the encoder scale 407 is disposed in a space thermally blocked from the control substrate 202 and the fixed cameras 101 to 106. Further, since the encoder scale 407 is also blocked from the flow path of the wind generated by the centrifugal fan A 401 by the pan base 405, the temperature rise of the encoder scale 407 by the control board 403 and the air warmed by the fixed cameras 101 to 106 is also It is reduced. As a result, the thermal expansion of the encoder scale 407 is reduced, so that the deterioration of the stop position accuracy due to the thermal expansion is reduced as in the first embodiment, and a highly accurate stop position accuracy can be realized.

[Example 3]
In the second embodiment, the thermal expansion of the encoder scale is reduced by disposing the encoder scale in a space thermally blocked with respect to the flow path of the fan to realize high-precision stop position accuracy. However, the same effect as the above-described embodiment can be obtained by forcibly cooling the part to which the encoder scale is attached with a fan or the like.

  FIG. 6 shows a multi-view camera as in the previous embodiment, and shows an internal structural view in a state in which the transparent cover 205 is removed. 7 is a detailed cross sectional view showing a cross section BB of FIG. The description of the same configuration as that of the above-described embodiment will be omitted.

  A tilt motor 502 for tilt drive is fixed to the tilt base 501 by screws (not shown), and a tilt gear 504 is fixed to the tilt unit 503 by screws (not shown). Further, a tilt belt 505 for transmitting the drive of the tilt motor 502 is hooked on the tilt pinion gear 506 and the tilt gear 504 of the tilt motor 502. A tilt motor driver substrate 507, which is a control substrate for controlling the tilt motor 502, is fixed to the tilt base 502. The tilt motor 502 is rotated at a desired rotational speed by the tilt motor driver substrate 507, and the tilt unit 503 is rotated at the desired rotational speed via the tilt belt 505 and the tilt gear 504.

  An encoder scale 508 is attached to the tilt base 501 as means for detecting the rotation of the tilt rotation angle, and an encoder sensor 509 is disposed at a position opposite to the encoder scale 508. Thus, the tilt rotation can be controlled by feedback control, but the detailed description will be omitted.

  Since the tilt motor 502 and the tilt motor driver substrate 507 are fixed to the tilt base 501, the heat of the tilt motor 502 and the tilt motor driver substrate 507 is transmitted to the tilt base 501. Since the tilt encoder scale 508 is attached on the surface of the tilt base 501, heat is also transmitted to the tilt encoder scale 508, and the detection result of the tilt encoder 510 is shifted by the expansion amount due to the temperature rise.

  In this embodiment, in order to reduce the expansion amount of the tilt encoder scale 508 due to the temperature rise, the tilt fan 511 is fixed to the surface of the tilt base 501 opposite to the surface to which the tilt encoder scale 508 is attached. The tilt fan 511 contributes to lowering the temperature of the tilt base 501 by causing air of a relatively cool space in the multi-view camera main body to hit the tilt base 501. As a result, it also contributes to lowering the temperature of the tilt encoder scale 508 attached to the tilt base 501.

  As a result, the rotational detection deviation amount of the expansion of the tilt encoder scale 508 due to the temperature rise is reduced, and highly accurate position accuracy can be realized.

  In the present embodiment, the tilt motor 502 is fixed to the tilt base 501, but may be fixed to the tilt unit 503. In that case, it is desirable to adopt a configuration in which the tilt fan 511 is disposed in the tilt unit 503. Further, a component to be cooled by the tilt fan 511 is used as a tilt base on which a tilt encoder scale 508 is attached. However, if the encoder sensor is more sensitive to temperature depending on the type of encoder to be selected, the effect does not change even if the configuration for cooling the components on the encoder sensor side is used.

Reference Signs List 1 multi-lens camera 101 to 106 fixed camera 107 pan and tilt camera 201 base 202 control board 204 bottom cover 206 pan base 207 pan gear 208 pan belt 209 tilt base 210 encoder scale 211 encoder sensor 212 optical encoder 213 stepping motor

Claims (5)

With several fixed cameras arranged circumferentially,
A pan and tilt camera disposed substantially at the center of the plurality of cameras;
A control substrate for controlling at least the pan and tilt camera;
Rotation detection means for detecting a pan rotation angle or a tilt rotation angle of the pan / tilt camera;
And a wall provided between the plurality of fixed cameras and the rotation detection means, and between the control substrate and the rotation detection means.
The image pickup apparatus, wherein the rotation detecting means is separated from the plurality of fixed cameras and the control board by the wall. A fixing portion for fixing the control substrate;
And a fan disposed at the fixed part,
The image pickup apparatus according to claim 1, wherein the rotation detection unit is disposed apart from an air path from the control substrate of the wind generated by the fan to the fixed camera. An imaging unit of the pan-tilt camera;
Tilt supporting means for supporting the imaging means in a tiltable manner;
Pan supporting means for rotatably supporting the tilt supporting means;
Pan driving means for pan rotating the pan supporting means provided with the tilt supporting means;
A pan control board for controlling the pan driving means disposed on the tilt supporting means;
And a pan drive fan for cooling the pan control substrate,
The image pickup apparatus according to claim 1, wherein the rotation detection unit is disposed on the tilt supporting unit cooled by the pan driving fan.   The imaging apparatus according to claim 1, wherein the rotation detection unit is an optical encoder including a light emitting element, a light receiving element, and an encoder scale.   The imaging device according to claim 1, wherein the encoder scale is made of resin.

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