Imaging apparatus

Abstract

To provide a technique for cleaning a slip ring, while reducing an imaging defect and the working load of an operator, in an imaging apparatus including the slip ring.SOLUTION: The imaging apparatus includes: a housing; an imaging part which is rotatably supported by the housing and images each of a plurality of monitoring positions; a slip ring which is stored in the housing and electrically connects the imaging part to an external device; and a control part which controls the operation of the imaging part. The plurality of monitoring positions include a first position and a second position separated in a circumferential direction. When the imaging part is rotated from a first attitude for imaging the first position to a second attitude for imaging the second position, the control part selects and performs one of a monitoring operation for rotating the imaging part in a forward direction and a cleaning operation for rotating the imaging part in a reverse direction opposite to the forward direction.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an imaging device provided with a slip ring.

Background Art

[0002] Conventionally, in a so-called "PTZ (Pan, Tilt, Zoom) camera", a slip ring is often used to maintain an electrical connection between a rotating component (for example, an imaging unit), a fixed component (for example, a control board), and an external device (for example, an external power source, a monitoring terminal).

[0003] A slip ring is a component that maintains an electrical connection even when the imaging unit is rotated by bringing a rotating terminal that rotates with the imaging unit into sliding contact with an electrical contact fixed to the housing. Therefore, there has been a problem that dust accumulates in a portion of the electrical contact where the rotating terminal does not slide contact over a long period of time.

[0004] Therefore, as a technology for solving such problems, there are a technology of performing a cleaning operation by rotating the imaging unit 360° at set time intervals (for example, see Patent Document 1), and a technology of forcibly performing a cleaning operation by an instruction from an operator (for example, see Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the cleaning operation of Patent Document 1, since the imaging unit is always rotated 360°, the time during which imaging is temporarily stopped (hereinafter, this is referred to as "imaging loss") increases. Further, in the cleaning operation of Patent Document 2, since the operator needs to instruct the cleaning operation at a desired timing, the work load on the operator increases.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a technique for cleaning a slip ring while reducing imaging loss and the work load on an operator in an imaging device provided with a slip ring.

Means for Solving the Problems

[0008] In order to solve the above problems, an imaging device according to the present invention includes a housing, an imaging unit rotatably supported by the housing for imaging each of a plurality of monitoring positions, a slip ring housed in the housing for electrically connecting the imaging unit to an external device, and a control unit for controlling the operation of the imaging unit. The plurality of monitoring positions include a first position and a second position spaced apart in the circumferential direction. When rotating the imaging unit from a first posture for imaging the first position to a second posture for imaging the second position, the control unit selects and executes either a monitoring operation of rotating the imaging unit in a forward direction or a cleaning operation of rotating the imaging unit in a reverse direction opposite to the forward direction.

Effects of the Invention

[0009] According to the present invention, in an imaging device provided with a slip ring, it is possible to clean the slip ring while reducing imaging loss and the work load on an operator. Note that problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0010]

Figure 1

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Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the invention will be described with reference to the drawings. This embodiment contributes to "9. Build the foundation for industry and technological innovation" among the Sustainable Development Goals (SDGs) proposed by the United Nations by realizing highly versatile imaging devices and detection devices.

[0012] [Overall Configuration of Imaging Device 1] FIG. 1 is an external perspective view of the imaging device 1. FIG. 2 is a perspective view of the imaging device 1 with the second housing 3 omitted. FIG. 3 is a hardware configuration diagram of the imaging device 1. Since the imaging device 1 has a well-known configuration, detailed description thereof will be omitted. For example, it has the following configuration. As shown in FIGS. 1 to 3, the imaging device 1 mainly includes a first housing 2, a second housing 3, an imaging unit 4, a Tilt motor 5, a Pan motor 6, an attitude sensor 7, a slip ring 8, a harness 9, and a control unit 10.

[0013] The imaging device 1 according to this embodiment is, for example, a so-called "PTZ camera" capable of Pan, Tilt, and Zoom. However, it suffices if the imaging device 1 can at least perform Pan. Also, the imaging device 1 according to this embodiment is, for example, a so-called "surveillance camera" installed on a ceiling or a wall to image the surroundings of the installation location. Furthermore, the imaging device 1 according to this embodiment operates, for example, by receiving power supply from an external power source (an example of an external device), and outputs video data indicating the captured video (or image) to a surveillance terminal (another example of an external device).

[0014] However, the imaging device 1 may operate with the power of the mounted battery. Also, the output of the imaging device 1 is not limited to video (moving image) data, and may be image (still image) data. Furthermore, the surveillance terminal may store (record) the video data acquired from the imaging device 1 in a memory, or may display the video indicated by the video data on a display.

[0015] The first housing 2 has an outer shape that is generally spherical. The first housing 2 houses the imaging unit 4. Also, the first housing 2 rotatably supports the imaging unit 4 around the first axis X1. Also, the surface of the first housing 2 that can face the lens of the imaging unit 4 is transparent or translucent. Furthermore, although not shown in FIGS. 1 and 2, the first housing 2 houses, for example, a Tilt motor 5 (see FIG. 3) that rotates the imaging unit 4 around the first axis X1.

[0016] The second housing 3 has an outer shape that is generally cylindrical. The second housing 3 rotatably supports the first housing 2 around the second axis X2 (rotation axis). Also, the second housing 3 is fixed to the ceiling. More specifically, the second housing 3 supports the first housing 2 at one end in the direction along the second axis X2, and the other end is fixed to the ceiling. Furthermore, the second housing 3 houses, for example, a Pan motor 6, an attitude sensor 7, a slip ring 8, and a control unit 10.

[0017] The first housing 2 and the second housing 3 are exterior covers that constitute the outer shell of the imaging device 1. Also, the first axis X1 and the second axis X2 are orthogonal to each other. Typically, the first axis X1 is an axis that extends parallel to the installation surface of the imaging device 1 (when the installation surface is the ceiling, it is in the horizontal direction). The second axis X2 is an axis that extends in a direction perpendicular to the installation surface of the imaging device 1 (when the installation surface is the ceiling, it is in the vertical direction). However, as long as the extending directions of the first axis X1 and the second axis X2 are orthogonal to each other, the absolute directions are not limited to the above examples. Hereinafter, the rotation around the first axis X1 may be denoted as "Tilt", and the rotation around the second axis X2 may be denoted as "Pan".

[0018] The imaging unit 4 is a camera unit in which an optical lens and an image sensor are integrated. The optical lens faces a transparent or translucent surface inside the first housing 2. The image sensor photoelectrically converts the light collected by the optical lens and outputs video data. The optical element is, for example, a CMOS (Complementary Metal-Oxide-Semiconductor) or a CCD (Charge-Coupled Device). The imaging unit 4 rotates (Tilt) around the first axis X1 by the rotational driving force of the Tilt motor 5. Also, the imaging unit 4 rotates (Pan) around the second axis X2 together with the first housing 2 by the rotational driving force of the Pan motor 6.

[0019] The Tilt motor 5 and the Pan motor 6 are stepping motors that rotate according to a pulse signal output from a control unit 10 described later. More specifically, the Tilt motor 5 and the Pan motor 6 rotate by an angle corresponding to the number of pulse signals (hereinafter, may be denoted as "number of steps") output from the control unit 10. Also, the Tilt motor 5 and the Pan motor 6 can rotate forward and backward.

[0020] FIG. 4 is a schematic view of the imaging unit 4 as viewed from the extending direction of the second axis X2. As shown in FIG. 4, the imaging unit 4 is supported by the second housing 3 so as to be rotatable 360° around the second axis X2. On the other hand, a plurality of monitoring positions A, B, and C spaced apart in the circumferential direction centered on the second axis X2 are set around the imaging device 1. Note that the number of monitoring positions is not limited to three and may be two or more (for example, 255).

[0021] Then, among the rotation range (360°) of the imaging unit 4, the range including all the monitoring positions A to C is denoted as the "monitoring range", and the other ranges are denoted as the "non-monitoring range". That is, the monitoring range is a single region continuous in the circumferential direction within the rotation range of the imaging unit 4. Similarly, the monitoring range is a single region continuous in the circumferential direction within the rotation range of the imaging unit 4. Further, the monitoring region and the non-monitoring region are separate regions (regions that do not overlap each other). Note that the entire circumference of the rotation range of the imaging unit 4 may be set as the monitoring range. However, in the present embodiment, as shown in FIG. 4, it is assumed that the rotation range of the imaging unit 4 is divided into a monitoring range and a non-monitoring range.

[0022] The imaging unit 4 rotates around the second axis X2 so as to image each of the plurality of monitoring positions A to C. Hereinafter, the orientations of the imaging unit 4 when imaging the monitoring positions A, B, and C are denoted as postures A, B, and C. The postures A, B, and C refer to, for example, the orientations of the imaging unit 4 (more specifically, the optical lens) when the monitoring positions A, B, and C are included in the imaging angle (more specifically, when the monitoring positions A, B, and C are at the center of the imaging angle).

[0023] In addition, the imaging unit 4 rotates in the poses A, B, and C in sequence so as to image a plurality of monitoring positions A to C in sequence. The imaging unit 4 according to the present embodiment images in the order of, for example, monitoring positions A, B, C, A, ··· (that is, rotates in the order of poses A, B, C, A, ···). However, the positions, numbers, and imaging orders of the monitoring positions A, B, and C are not limited to the above examples and can be arbitrarily set by the operator. Among the poses before and after the rotation of the imaging unit 4, the pose before rotation is the first pose, and the pose after rotation is the second pose. Also, the monitoring position imaged by the imaging unit 4 in the first pose is the first position, and the monitoring position imaged by the imaging unit 4 in the second pose is the second position.

[0024] Furthermore, when the imaging unit 4 switches the monitoring position (that is, rotates from the first pose to the second pose), it generally rotates through the monitoring range. In the example of FIG. 4, the imaging unit 4 rotates clockwise from pose A (the first pose) toward pose B (the second pose), rotates clockwise from pose B (the first pose) toward pose C (the second pose), and rotates counterclockwise from pose C (the first pose) toward pose A (the second pose).

[0025] Hereinafter, among the rotation directions of the imaging unit 4 (clockwise and counterclockwise in FIG. 4), the direction from the first pose to the second pose passing only through the monitoring range is denoted as the "forward direction", and the direction from the first pose to the second pose passing through the non-monitoring range is denoted as the "reverse direction". Also, as shown in FIG. 4, when the monitoring range is narrower than the non-monitoring range (in other words, the central angle of the monitoring range is less than 180°), among the rotation directions of the imaging unit 4 (clockwise and counterclockwise in FIG. 4), the side with the smaller rotation angle from the first pose to the second pose is the "forward direction", and the side with the larger rotation angle is the "reverse direction".

[0026] That is, the forward direction and the reverse direction are opposite to each other. Also, the forward direction and the reverse direction do not refer to absolute directions common to all poses, but are directions that vary according to the combination of the first pose and the second pose (however, once the combination of the first pose and the second pose is determined, they are uniquely determined).

[0027] The attitude sensor 7 detects the attitude of the imaging unit 4 and outputs an attitude signal indicating the detected attitude to the control unit 10. The attitude sensor 7 is composed of, for example, a reference sensor (such as an origin sensor) that detects the reference attitude (rotation angle = 0°) of the imaging unit 4 and a rotation sensor (such as a rotary encoder) that detects the rotation angle of the imaging unit 4 from the reference attitude. The control unit 10, for example, sets the cumulative value at the time when the reference attitude of the imaging unit 4 is detected by the origin sensor to 0, and specifies the attitude (rotation angle) of the imaging unit 4 by adding or subtracting the pulse signal output from the rotary encoder to the cumulative value.

[0028] The slip ring 8 is a component that electrically connects the rotating parts of the imaging device 1 (such as the imaging unit 4, Tilt motor 5), the fixed parts of the imaging device 1 (such as the Pan motor 6, control unit 10), and an external device (such as an external power source, monitoring terminal) via a harness 9. The slip ring 8, for example, makes the rotating terminal that rotates together with the rotating part slide-contact with the electrical contact fixed to the second housing 3. Thereby, even when the first housing 2 and the imaging unit 4 (rotating side) rotate with respect to the second housing 3 (fixed side), the electrical contact is maintained. Since the specific configuration of the slip ring 8 is already well-known, a detailed description is omitted.

[0029] The control unit 10 includes a CPU (Central Processing Unit) 11 and a memory 12. The memory 12 is composed of, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), an HDD (Hard Disk Drive), or a combination thereof. The control unit 10 realizes the processes described later by the CPU 11 reading and executing the program codes stored in the ROM or HDD. The RAM is used as a work area when the CPU 11 executes a program.

[0030] However, the specific configuration of the control unit 10 is not limited to this, and it may be implemented by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

[0031] The control unit 10 outputs a pulse signal to rotate the Tilt motor 5 and the Pan motor 6. Also, the control unit 10 identifies the posture of the imaging unit 4 based on the posture signal output from the posture sensor 7. Furthermore, the control unit 10 starts and stops the imaging of the imaging unit 4 according to the control of the monitoring terminal, and outputs the video data generated by the imaging unit 4 to the monitoring terminal.

[0032] Here, if the imaging unit 4 rotates only in the forward direction (that is, the imaging unit 4 rotates only within the monitoring range), the rotating terminal only slides in contact with a part of the circumferential direction of the electric contact. Therefore, dust may accumulate in the part where the rotating terminal of the electric contact does not slide in contact. Thus, the control unit 10 executes the monitoring control process shown in FIG. 5 to remove (clean) the dust deposited on the slip ring 8 while continuing the imaging (monitoring) of the surroundings by the imaging unit 4.

[0033] [Monitoring Control Process According to the First Embodiment] FIG. 5 is a flowchart of the monitoring control process according to the first embodiment. The control unit 10 starts the monitoring control process, for example, in response to obtaining an instruction to start imaging of the imaging unit 4 from the monitoring terminal, and continues the monitoring control process until it obtains an instruction to end imaging from the monitoring terminal.

[0034] Note that in the monitoring control process according to the first embodiment, it is premised that the imaging unit 4 is stationary in the first posture and imaging is continued at the first position for a predetermined time (second time), and then the imaging unit 4 is rotated at high speed from the first posture to the second posture. While the imaging unit 4 is rotating, imaging (monitoring) may be continued or interrupted. That is, in the first embodiment, as long as at least each monitoring position A, B, and C is imaged, it is not necessary to image the entire monitoring range.

[0035] First, the control unit 10 causes the imaging unit 4 to start imaging in the initial posture A (S11). That is, the control unit 10 rotates the imaging unit 4 to the posture A by driving the Pan motor 6. However, if the imaging unit 4 is already in the posture A, this process is omitted. Then, the control unit 10 causes the imaging unit 4 in the posture A to transmit video data including the monitoring position A to the monitoring terminal through the slip ring 8 and the harness 9.

[0036] Also, the control unit 10 starts a cleaning timer set for the first time (S12). Further, the control unit 10 starts a monitoring timer set for the second time (S13). The first time is the interval (for example, 1 hour, 24 hours) from when the cleaning operation was last executed to when the next cleaning operation is executed. The second time is the time (for example, 5 seconds, 10 minutes) for the imaging unit 4 to be stationary in each posture. In other words, the second time is the time to continue imaging (monitoring) the current monitoring position. That is, the first time is a time sufficiently longer than the second time. Hereinafter, "the timer times out" means that the set time has elapsed.

[0037] Next, the control unit 10 waits for the execution of the processes after step S15 until the monitoring timer times out (S14: No), and continues imaging (monitoring of the current monitoring position) by the imaging unit 4 in the current posture A. Then, when the monitoring timer times out (that is, until the imaging unit 4 remains stationary for the second time in the current posture) (S14: Yes), the control unit 10 determines whether the cleaning timer started in the most recent step S12 has already timed out (that is, whether the first time has elapsed since the previous cleaning operation) (S15).

[0038] Then, when the monitoring timer times out and the cleaning timer has not timed out yet (S15: No), the control unit 10 rotates the imaging unit 4 in the forward direction from the current posture A (the first posture) toward the next posture B (the second posture) (S16). The operation in step S16 is an example of the monitoring operation. Further, when the control unit 10 detects that the imaging unit 4 has reached the next posture B based on the posture sensor of the posture sensor 7, the control unit 10 sets the posture B as the new first posture and the posture C as the new second posture, and executes the processing after step S13.

[0039] On the other hand, when the monitoring timer times out and the cleaning timer has already timed out at that time (S15: Yes), the control unit 10 rotates the imaging unit 4 in the reverse direction from the current posture A (the first posture) toward the next posture B (the second posture) (S17). The operation in step S17 is an example of the cleaning operation. Further, when the control unit 10 detects that the imaging unit 4 has reached the next posture B based on the posture sensor of the posture sensor 7, the control unit 10 sets the posture B as the new first posture and the posture C as the new second posture, and executes the processing after step S12.

[0040] Furthermore, after the control unit 10 sets the posture B as the first posture and the posture C as the second posture and executes the processing after step S12 (or step S13), the control unit 10 sets the posture C as the new first posture and the posture A as the new second posture, and executes the processing after step S12 (or step S13). Hereinafter, the combination of the first posture and the second posture is swapped, and the processing after step S12 (or step S13) is repeatedly executed.

[0041] Here, since the monitoring timer is shorter than the cleaning timer, the control unit 10 repeatedly executes the monitoring operation (S16) until the cleaning timer times out. Then, in the process of repeatedly executing the monitoring operation (S16), the control unit 10 executes the cleaning operation (S17) each time the cleaning timer times out. However, the control unit 10 executes the cleaning operation when the cleaning timer has timed out at the timing when the monitoring in the current posture ends (i.e., the monitoring timer has timed out), rather than at the moment when the cleaning timer has just timed out.

[0042] FIG. 6 is a diagram showing how the imaging unit 4 rotates from posture A to posture B. As shown in FIG. 6, when the control unit 10 executes the monitoring operation (S16) with posture A as the first posture and posture B as the second posture, the control unit 10 rotates the imaging unit 4 clockwise to reach from posture A to posture B only through the monitoring range. On the other hand, when the control unit 10 executes the cleaning operation (S17) with posture A as the first posture and posture B as the second posture, the control unit 10 rotates the imaging unit 4 counterclockwise to reach from posture A to posture B through the non-monitoring range and a part of the monitoring range (between the monitoring positions B - C).

[0043] FIG. 7 is a diagram showing how the imaging unit 4 rotates from posture B to posture C. As shown in FIG. 7, when the control unit 10 executes the monitoring operation (S16) with posture B as the first posture and posture C as the second posture, the control unit 10 rotates the imaging unit 4 clockwise to reach from posture B to posture C only through the monitoring range. On the other hand, when the control unit 10 executes the cleaning operation (S17) with posture B as the first posture and posture C as the second posture, the control unit 10 rotates the imaging unit 4 counterclockwise to reach from posture B to posture C through the non-monitoring range and a part of the monitoring range (between the monitoring positions B - A).

[0044] FIG. 8 is a diagram showing how the imaging unit 4 rotates from the posture C to the posture A. As shown in FIG. 8, when the control unit 10 executes the monitoring operation (S16) with the posture C as the first posture and the posture A as the second posture, the control unit 10 rotates the imaging unit 4 counterclockwise to reach from the posture C to the posture A only through the monitoring range. On the other hand, when the control unit 10 executes the cleaning operation (S17) with the posture C as the first posture and the posture A as the second posture, the control unit 10 rotates the imaging unit 4 clockwise to reach from the posture C to the posture A through the non-monitoring range.

[0045] Note that as shown in FIGS. 6 to 8, in the monitoring operation (S16), the imaging unit 4 rotates from the first posture to the second posture only through the monitoring range and without passing through the non-monitoring range. Also, as shown in FIGS. 6 and 7, in the cleaning operation (S17), the imaging unit 4 may rotate from the first posture to the second posture through a part of the non-monitoring range and the monitoring range. Further, as shown in FIG. 8, in the cleaning operation (S17), the imaging unit 4 may rotate from the first posture to the second posture only through the non-monitoring range and without passing through the monitoring range.

[0046] [Operation and Effect of the First Embodiment] According to the first embodiment, when rotating the imaging unit 4 from the first posture to the second posture, either the monitoring operation or the cleaning operation is selected and executed. As a result, the rotating terminal slidably contacts not only the portion that slidably contacts during the monitoring operation but also the entire circumference in the circumferential direction of the electrical contact of the slip ring 8. As a result, the dust deposited on the slip ring 8 can be appropriately cleaned.

[0047] Here, as shown in FIGS. 6 to 8, since the rotation angle of the imaging unit 4 from the first posture to the second posture is always less than 360°, imaging defects can be reduced as compared with the technique of Patent Document 1 in which the cleaning operation always rotates 360°. Also, since the control unit 10 selects the monitoring operation and the cleaning operation, the work load of the operator can be reduced as compared with the technique of Patent Document 2 in which the cleaning operation is executed in response to an instruction from the operator.

[0048] Also, according to the first embodiment, even if the cleaning timer times out while the imaging unit 4 is stationary in the first posture, the monitoring of the first position is continued until the monitoring timer times out, and the cleaning operation is executed after the monitoring timer times out (S14: Yes & S15: Yes → S17). Thereby, it is possible to prevent the monitoring of the first position from being interrupted and the occurrence of imaging loss.

[0049] Furthermore, since the first time is set to be sufficiently longer than the second time, the frequency of occurrence of the cleaning operation can be made lower compared to the monitoring operation. Thereby, the imaging loss in the monitoring range can be further reduced. For example, the first time may be set to be 2 times or more, more desirably 10 times or more, of the second time.

[0050] [Second Embodiment] FIG. 9 is a flowchart of the monitoring control process according to the second embodiment. Note that a detailed description of the common points with the first embodiment is omitted, and the description will focus on the differences. In the monitoring control process according to the second embodiment, the imaging unit 4 is not stationary in each posture (except for the momentary stillness when the rotation direction reverses), and it is assumed that the entire monitoring range is imaged (monitored) by slowly reciprocating the imaging unit 4 between one end (posture A) and the other end (posture C) of the monitoring range. That is, the imaging unit 4 continues imaging (monitoring) even while rotating. Also, at the start point of the monitoring control process, it is assumed that the imaging unit 4 is in an arbitrary posture.

[0051] First, the control unit 10 causes the imaging unit 4 to start imaging and rotates the imaging unit 4 in the forward direction at the first speed toward the first posture A (S21). If the imaging unit 4 is already in the posture A at the start point of the monitoring control process, the process of step S21 is skipped. Also, the control unit 10 starts a cleaning timer set for the first time (S22). Furthermore, the control unit 10 waits for the execution of the processes after step S24 until the imaging unit 4 reaches the posture A (S23: No). Note that the imaging unit 4 continues imaging (outputting imaging data) even while rotating.

[0052] Next, when the control unit 10 detects that the imaging unit 4 has reached the posture A based on the posture sensor of the posture sensor 7 (S23: Yes), it determines whether the cleaning timer started in the most recent step S22 has already timed out (S24).

[0053] And when the cleaning timer has not yet timed out at the time when the imaging unit 4 reaches the posture A (S24: No), the control unit 10 rotates the imaging unit 4 forward at the first speed from the current posture A (the first posture) toward the next posture B (the second posture) (S25). The operation in step S25 is an example of the monitoring operation. Further, the control unit 10 executes the processing after step S23 with the posture B as the new first posture and the posture C as the new second posture.

[0054] On the other hand, when the cleaning timer has already timed out at the time when the imaging unit 4 reaches the posture A (S24: Yes), the control unit 10 rotates the imaging unit 4 backward at the second speed from the current posture A (the first posture) toward the next posture B (the second posture) (S26). The operation in step S26 is an example of the cleaning operation. Further, the control unit 10 executes the processing after step S22 with the posture B as the new first posture and the posture C as the new second posture.

[0055] Note that the first speed and the second speed refer to, for example, the average value or the maximum value of the rotation speed (angular velocity) of the imaging unit 4. And the second speed is faster than the first speed. Also, the imaging unit 4 continues imaging (output of video data) in the monitoring operation. On the other hand, in the cleaning operation, the imaging unit 4 may continue imaging (output of video data) or may be interrupted (temporarily stopped). That is, the imaging unit 4 images the monitoring range between the first position and the second position while rotating at a low speed in the monitoring operation. On the other hand, in the cleaning operation, the imaging unit 4 passes through the non-monitoring range (or a part of the non-monitoring range and the monitoring range) from the first posture to the second posture at a high speed.

[0056] Furthermore, after executing the processes after step S22 (or step S23) with posture B as the first posture and posture C as the second posture, the control unit 10 executes the processes after step S22 (or step S23) again with posture C as the new first posture and posture A as the new second posture. Hereinafter, the combinations of the first posture and the second posture are swapped, and the processes after step S22 (or step S23) are repeatedly executed.

[0057] [Operation and Effect of Second Embodiment] According to the second embodiment, the imaging unit 4 is rotated at the first speed in the monitoring operation (S25), and the imaging unit 4 is rotated at the second speed in the cleaning operation (S26). Thereby, in the monitoring operation, the monitoring range can be appropriately imaged, and imaging omission in the cleaning operation can be reduced.

[0058] Also, according to the second embodiment, even if the cleaning timer times out while the imaging unit 4 is rotating, the monitoring of the monitoring range is continued until the imaging unit 4 reaches the next posture, and the cleaning operation is executed after the imaging unit 4 reaches the next posture (S23: Yes & S24: Yes → S26). Thereby, it is possible to prevent the monitoring of the monitoring range from being interrupted and imaging omission from occurring.

[0059] As described above, various embodiments have been described with reference to the drawings, but it goes without saying that the present disclosure is not limited to such examples. It is obvious that those skilled in the art can conceive of various modification examples, correction examples, substitution examples, addition examples, deletion examples, and equivalent examples within the scope described in the claims, and it is naturally understood that they also belong to the technical scope of the present disclosure. Further, within the scope not departing from the gist of the invention, the components in the above-described various embodiments may be arbitrarily combined.

Industrial Applicability

[0060] The present disclosure is useful as an imaging device capable of cleaning a slip ring while reducing imaging omission and the work load of an operator.

Explanation of Reference Numerals

[0061] 1 Imaging device 2 First housing 3 Second housing 4 Imaging unit 5 Tilt motor 6 Pan motor 7 Attitude sensor 8 Slip ring 9 Harness 10 Control unit 11 CPU 12 Memory

Claims

1. A housing, an imaging unit rotatably supported by the housing and configured to image each of a plurality of monitoring positions, a slip ring housed in the housing and configured to electrically connect the imaging unit to an external device, and a control unit configured to control the operation of the imaging unit, wherein the plurality of monitoring positions include a first position and a second position spaced apart in the circumferential direction, and when the control unit rotates the imaging unit from a first posture for imaging the first position to a second posture for imaging the second position, the control unit selects and executes either a monitoring operation of rotating the imaging unit in a forward direction or a cleaning operation of rotating the imaging unit in a reverse direction opposite to the forward direction. An imaging device.

2. The imaging device according to claim 1, wherein the control unit executes the cleaning operation each time a first period of time elapses during a process of repeatedly executing the monitoring operation among the plurality of monitoring positions.

3. The imaging unit remains stationary in the first posture until a second period of time shorter than the first period of time elapses and then rotates to the second posture, and when the imaging unit has remained stationary in the first posture for the second period of time, the control unit executes the monitoring operation when the first period of time has not yet elapsed since the previous cleaning operation, and executes the cleaning operation when the first period of time has already elapsed since the previous cleaning operation. The imaging device according to claim 2.

4. When the imaging unit reaches the first posture, the control unit executes the monitoring operation when the first period of time has not yet elapsed since the previous cleaning operation, and executes the cleaning operation when the first period of time has already elapsed since the previous cleaning operation. The imaging device according to claim 2.

5. The control unit, in the monitoring operation, rotates the imaging unit in the forward direction at a first speed, and in the cleaning operation, rotates the imaging unit in the reverse direction at a second speed higher than the first speed. The imaging device according to claim 1.

6. The rotation range of the imaging unit is divided into a monitoring range including all of the monitoring positions and a non-monitoring range different from the monitoring range, the forward direction is a direction in which the imaging unit is rotated from the first posture to the second posture only through the monitoring range, and the reverse direction is a direction in which the imaging unit is rotated from the first posture to the second posture through the non-monitoring range. The imaging device according to claim 1.

7. The imaging device according to claim 1, wherein, among the clockwise and counterclockwise directions, the side with a smaller rotation angle from the first posture to the second posture is the forward direction, and the side with a larger rotation angle is the reverse direction.

Images