Imaging unit support device and method for controlling the same

Abstract

To prevent an imaging unit from unexpectedly tilting and rotating when energization is cut off.SOLUTION: When a tilt axis motor 74 is energized, stationary period torque TX applied to the tilt axis motor 74 is detected in a stationary state in a tilt direction of an imaging unit. When the stationary period torque TX exceeds threshold torque TH, notification processing is executed.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to an imaging unit support device and a control method thereof. [Background technology]

[0002] Conventionally, imaging unit support devices that support an imaging unit have been known. For example, some pan-tilt camera systems for video production have a pan-tilt head that serves as an imaging unit support device to which the imaging unit can be detached. Some imaging units have a camera body to which an interchangeable lens can be detached.

[0003] Since the weight and center of gravity differ depending on the imaging unit, it is necessary to adjust the center of gravity every time you replace the imaging unit. If the center of gravity adjustment is not performed correctly, too much load will be placed on the tilt axis, making the tilt rotation difficult or causing the tilt axis to rotate unintentionally due to being unable to support the weight.

[0004] For this reason, various ideas have been devised to adjust the center of gravity in the past. For example, in Patent Document 1, the direction in which the center of gravity should be adjusted is estimated from the holding current of the motor and displayed to assist the user in adjusting the center of gravity.

[0005] Furthermore, changing the interchangeable lens may change the center of gravity of the imaging unit. Furthermore, the zoom ring for changing the shooting angle of the interchangeable lens and the focus ring for changing the focal position are operated. These operations may cause the zoom group or focus group in the interchangeable lens to move in the direction of the optical axis, which may change the center of gravity of the interchangeable lens. During shooting, the motor generally generates a holding torque, which is the force that supports the rotation of the tilt axis, so the change in the center of gravity is not very noticeable. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2005-70612 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, when shooting is finished and the power is switched off, the holding torque suddenly disappears. Then, the imaging unit tilts unintentionally due to its own weight, and there is a risk that a part of the imaging unit (interchangeable lens, etc.) may collide with a surrounding structure (support, etc.). In addition, if the pan-tilt head is placed on a tripod, etc., there is a risk that the pan-tilt head may fall over together with the tripod due to the imaging unit tilting unintentionally when the power is turned off.

[0008] An object of the present invention is to prevent the imaging unit from inadvertently tilting when power is cut off. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the imaging unit support device of the present invention is characterized in having a support part that supports the imaging unit rotatably in a tilt direction, a motor that rotates the imaging unit in the tilt direction, a detection means that detects a stationary torque applied to the motor while the imaging unit is stationary in the tilt direction when the motor is in an energized state, and a control means that performs an alarm process when the stationary torque detected by the detection means exceeds a threshold value. Effect of the Invention

[0010] According to the present invention, it is possible to prevent the imaging unit from tilting inadvertently when power is cut off. [Brief description of the drawings]

[0011] [Figure 1] 1 is an overall view of a pan-tilt camera system to which an imaging unit support device is applied. [Diagram 2] FIG. 1 is a schematic perspective view of a pan-tilt camera. [Diagram 3] FIG. 2 is a block diagram of the main functions of the pan-tilt camera. [Figure 4]FIG. 2 is a side view of the pan-tilt camera after the center of gravity has been adjusted. [Diagram 5] FIG. 13 is a diagram showing a state in which the zoom group has moved to the subject side in the optical axis direction. [Figure 6] FIG. 2 is an enlarged view of the external controller. [Figure 7] FIG. 4 is a side view of the pan-tilt camera after the retraction operation. [Figure 8] 13 is a flowchart of a process when power is turned off. [Figure 9] FIG. 2 is a perspective view of a pan-tilt camera suspended from a ceiling. [Figure 10] FIG. 2 is a side view of the pan-tilt camera after the center of gravity has been adjusted. [Figure 11] FIG. 13 is a diagram showing a state in which the zoom group has moved to the subject side in the optical axis direction. [Figure 12] FIG. 4 is a side view of the pan-tilt camera after the retraction operation. [Figure 13] 13 is a flowchart of a process when power is turned off. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] (First embodiment) 1 is an overall view of a pan-tilt camera system to which an imaging unit support device according to a first embodiment of the present invention is applied. This pan-tilt camera system is configured by connecting a pan-tilt camera 1, an external controller 2, and an external monitor 3 via a network. The type of the network is not important.

[0014] The pan-tilt camera 1 operates upon receiving a control signal from an external controller 2. An external monitor 3 receives a video signal output from the pan-tilt camera 1 and displays the video. Therefore, a user can operate the external controller 2 from a position away from the pan-tilt camera 1 and freely move the pan-tilt camera 1 remotely while watching the external monitor 3. The external controller 2 has a display panel 11.

[0015] 2 is a schematic perspective view of the pan-tilt camera 1. The pan-tilt camera 1 is roughly composed of a fixed base 4, a swivel head 5, a camera section 6, and a lens unit 9.

[0016] The fixed base 4 is a base, such as a tripod, for installing the pan-tilt camera 1 wherever necessary. The fixed base 4 holds the swivel head 5 by a rotation holding mechanism including a bearing (not shown). This allows the swivel head 5 to rotate relatively to the fixed base 4 about a pan rotation axis 7 indicated by a dashed line.

[0017] Additionally, the camera unit 6 is pivotally supported by the swivel head 5 about a tilt rotation axis 8. This allows the camera unit 6 to rotate about the tilt rotation axis 8 that is perpendicular to the pan rotation axis 7, relative to the swivel head 5 serving as a support unit.

[0018] The camera unit 6 is the main body of a digital video camera for capturing images, and an image sensor board (not shown) is housed in the housing of the camera unit 6. In addition to a detachable and replaceable lens unit 9, a follow focus 10 is attached to the camera unit 6. The optical axis of the lens unit 9 is referred to as optical axis C0. The "imaging unit" includes the camera unit 6 and the lens unit 9. The imaging unit support device that supports the imaging unit includes a swivel head 5 and a fixed base 4.

[0019] 3 is a block diagram of the main functions of the pan-tilt camera 1. The pan-tilt camera 1 has a CPU 71, a ROM 72, a RAM 73, a tilt axis motor 74, a pan axis motor 75, a memory 76, and a follow focus driving unit 77. The CPU 71 controls the entire pan-tilt camera 1. The ROM 72 stores a control program executed by the CPU 71. The RAM 73 provides a work area when the CPU 71 executes various processes. The memory 76 is a non-volatile storage medium, and stores various data.

[0020] A circuit board for operation is disposed on the fixed base 4. This circuit board includes a CPU 71, a ROM 72, a RAM 73, a memory 76, etc. This circuit board supplies power to the pan axis motor 75, the tilt axis motor 74, and the camera unit 6, and can receive control signals from the external controller 2 to perform various controls.

[0021] The pan axis motor 75 is built into the fixed base 4. The pan axis motor 75 pans and rotates the swivel head 5 and the imaging unit together around the pan rotation axis 7. This allows the imaging direction of the camera unit 6 to be set to any azimuth angle. Therefore, if the fixed base 4 is placed on a stand or attached to a predetermined position so that the pan rotation axis 7 is vertical, the azimuth angle of the camera unit 6 can be remotely controlled by panning the swivel head 5.

[0022] The tilt axis motor 74 is built into the swivel head 5. The tilt axis motor 74 as a drive unit tilts and rotates the camera unit 6 about the tilt rotation axis 8. Therefore, both the azimuth angle and the elevation angle can be remotely controlled.

[0023] In this way, the pan-tilt camera system is a system that can remotely control the azimuth angle and the angle of attack of the camera unit 6 of the pan-tilt camera 1 and distribute the captured images via the Internet or the like.

[0024] The follow focus driving unit 77, the follow focus 10, the zoom ring 12, the focus ring 13, the zoom group 14, and the focus group 15 will be described later.

[0025] Because the lens unit 9 is replaceable, the position of the center of gravity and the weight of the entire imaging unit change every time the lens unit 9 is replaced. The greater the deviation in the position of the center of gravity, the greater the torque applied to the tilt axis (around the tilt center). Therefore, as with a typical pan-tilt camera system, center of gravity adjustment is performed to reduce the torque applied to the tilt axis.

[0026] The center of gravity adjustment is now explained. The center of gravity adjustment is realized, for example, by changing the fixing position of the camera unit 6 with respect to a bracket (not shown) provided on the swivel head 5.

[0027] In adjusting the center of gravity, the user first supports the camera unit 6 with his / her hand so that the optical axis C0 is horizontal with no current being applied to the tilt axis motor 74 in order to adjust the center of gravity of the imaging unit in the direction of the optical axis C0 (hereinafter sometimes referred to as the optical axis direction). The user then checks whether the camera unit 6 tilts (rotates around the tilt center) under its own weight when the user releases his / her hand from that state. If the camera unit 6 rotates under its own weight, the direction of the deviation of the center of gravity in the optical axis direction can be confirmed based on the direction of rotation. The user then moves the camera unit 6 in the direction of the optical axis that reduces the deviation of the center of gravity, and adjusts it until the camera unit 6 no longer rotates under its own weight even when the user releases his / her hand.

[0028] Next, in order to check the deviation of the center of gravity of the imaging unit in a direction perpendicular to the optical axis direction and the tilt rotation axis 8 direction, the user supports the camera unit 6 with his / her hand so that the optical axis C0 is vertical with no current being applied to the tilt axis motor 74. The user then checks whether the camera unit 6 tilts under its own weight when the user releases his / her hand from that state. If the camera unit 6 rotates under its own weight, the direction of the deviation of the center of gravity in a direction perpendicular to the optical axis direction and the tilt rotation axis 8 direction can be checked based on the direction of rotation. The user then moves the camera unit 6 in a direction that reduces the deviation of the center of gravity, and adjusts it until the camera unit 6 does not rotate under its own weight even when the user releases his / her hand.

[0029] By adjusting the center of gravity, the tilt center and the center of gravity are preferably aligned, eliminating the center of gravity shift. However, it is not essential to provide a mechanism for adjusting the center of gravity shift in a direction perpendicular to the optical axis direction and the tilt rotation axis 8 direction.

[0030] When taking a photograph, the user moves the zoom group 14 and the focus group 15 (FIG. 3) in the lens unit 9 to adjust the angle of view and focus of the lens unit 9. The user can rotate the zoom ring 12 (FIG. 3) when moving the zoom group 14, and can rotate the focus ring 13 (FIG. 3) when moving the focus group 15.

[0031] Here, an electric follow focus 10 is used to remotely operate the zoom ring 12 and the focus ring 13. Gears (not shown) of the follow focus 10 mesh with concaves and convexes (not shown) of the zoom ring 12 and the focus ring 13. Therefore, the zoom ring 12 and the focus ring 13 can be operated by the follow focus 10.

[0032] Fig. 4 is a side view of the pan-tilt camera 1 after the center of gravity adjustment has been performed. Although Fig. 3 shows that both the zoom ring 12 and the focus ring 13 can be driven by the follow focus 10, the follow focus 10 may be capable of driving only one of the zoom ring 12 or the focus ring 13. Fig. 4 shows an example in which only the zoom ring 12 can be driven by the follow focus 10. Note that separate follow focuses may be provided for operating the zoom ring 12 and for operating the focus ring 13.

[0033] The follow focus driver 77 shown in FIG. 3 is an actuator that drives the follow focus 10 to change its position, and is controlled by the CPU 71. When the drive position of the follow focus 10 changes, the zoom group 14 moves in the optical axis direction via the zoom ring 12. The drive position of the follow focus 10 is measured by an encoder (not shown). The encoder coordinates, which are the measurement results, are stored in the memory 76. Note that a configuration that uses this measurement result will be described in the second embodiment. In this embodiment, it is not essential to measure the drive position of the follow focus 10.

[0034] FIG. 5 is a side view of the pan-tilt camera 1 after the center of gravity adjustment has been performed, showing a state in which the zoom group 14 has moved toward the subject side in the optical axis direction from the state shown in FIG.

[0035] With the center of gravity adjusted, the follow focus 10 is driven, and as a result of the zoom group 14 moving toward the subject, the center of gravity of the imaging section including the lens unit 9 moves toward the subject. When the power to the pan-tilt camera 1 is turned off (shut off) in this state, the holding torque by the tilt axis motor 74 disappears. At this time, if the movement of the center of gravity is large and the tilt axis mechanism can no longer support the weight of the imaging section by friction alone, there is a risk that the imaging section will tilt.

[0036] Therefore, in this embodiment, as described in detail below, the CPU 71 constantly monitors the torque (load) of the tilt axis motor 74. If the stationary torque of the tilt axis motor 74 when tilt rotation is stationary exceeds a threshold value, the CPU 71 issues a warning through notification processing. This prevents the imaging unit from tilting unintentionally when the power is turned off.

[0037] 6 is an enlarged view of the external controller 2. In the notification process, the CPU 71 displays a warning on the display panel 11 of the external controller 2. When displaying the warning, the pan-tilt camera 1 sends a corresponding warning signal to the external controller 2, and the external controller 2, upon receiving the warning signal, displays information corresponding to the warning signal on the display panel 11. As an example of this warning display, a message saying "The camera will tip over if the power is turned off" is displayed.

[0038] In the notification process, the fact that the imaging unit will tilt when the power is turned off may be notified by at least one of a display and a sound. Alternatively, a method of displaying a predetermined warning mark or lighting a predetermined LED may be adopted. For example, the notification may be given by the lighting color or lighting mode (blinking, etc.) of the tally lamp. Note that the warning display is not limited to the external controller 2, and a small display may be provided on the pan-tilt camera 1, and a warning or the like may be displayed on this display.

[0039] Here, the torque TY (known), the stationary torque TX (variable), and the threshold torque TH used in this embodiment are defined.

[0040] Torque TY is the minimum torque value at which tilt rotation occurs when no current is applied to tilt axis motor 74, assuming that the center of gravity of the imaging unit and the tilt center (tilt rotation axis 8) coincide when viewed from the direction of tilt rotation axis 8. Torque TY is generated mainly by static friction in the axis, and is generally greater than 0.

[0041] The stationary torque TX is the torque applied to the tilt axis motor 74 while the imaging unit is stationary in the tilt direction when current is applied to the tilt axis motor 74. In other words, the stationary torque TX is the holding torque when a holding current is applied to the tilt axis motor 74 so that tilt rotation does not occur in the imaging unit. If the center of gravity of the imaging unit and the tilt center coincide with each other, the stationary torque TX will be at a minimum value (known).

[0042] The threshold torque TH is a value that is determined in advance as a value smaller than the torque TY. Information on the torque TY and the threshold torque TH is stored in advance in the ROM 72. The CPU 71 as a detection means detects the stationary torque TX based on the value of the current flowing through the tilt axis motor 74.

[0043] Here, a method for detecting the static torque TX will be described. Generally, a DC servo motor, a brushless motor, or a stepping motor is used for a tilt axis motor. In the case of a DC servo motor, the static torque is proportional to the value of the current flowing through the windings, so if the proportionality constant is known in advance, it is possible to detect the static torque by measuring the value of the current flowing through the windings.

[0044] In this embodiment, a DC servo motor is used for the tilt axis motor 74. The CPU 71 constantly measures the value of the current flowing through the windings of the tilt axis motor 74, and detects the stationary torque TX by converting this measurement value into torque.

[0045] It should be noted that a brushless motor or a stepping motor may be used as the tilt axis motor 74. Even when such a motor is used, if a control method using a current feedback loop, such as so-called vector control, is used, it is possible to detect the static torque TX using the results of measuring the current value.

[0046] The CPU 71 as a control means cuts off the power supply to the tilt axis motor 74 in response to an instruction to cut off the power supply (for example, an instruction to end shooting) while the tilt axis motor 74 is energized. Before cutting off the power supply, the CPU 71 performs a notification process as necessary. First, when an instruction to cut off the power supply is received, the CPU 71 stops the tilt rotation, and detects the stationary torque TX based on the current value flowing through the tilt axis motor 74 in this state. Then, when the stationary torque TX exceeds a threshold torque TH, the CPU 71 issues a warning by notification process that there is a risk of tilt rotation due to power off (FIG. 6).

[0047] The CPU 71 may perform a retraction operation before cutting off the power supply to the tilt axis motor 74. As the retraction operation, for example, the CPU 71 tilts the imaging unit to a retract angle position and then cuts off the power supply to the tilt axis motor 74.

[0048] Fig. 7 is a side view of the pan-tilt camera 1 after the retraction operation. In Fig. 7, the imaging unit has tilted in the clockwise direction in Fig. 7 to a retraction angle position θ with the optical axis C0 horizontal as the reference (0).

[0049] When the CPU 71 determines that the threshold torque TH is smaller than the stationary torque TX and that the imaging unit tilts in the clockwise direction in Fig. 7 immediately after the power is cut off, the CPU 71 tilts the imaging unit to the retract angle position θ shown in Fig. 7. The rotation direction of the imaging unit immediately after the power is cut off is determined from the sign of the stationary torque TX.

[0050] The retracted angular position θ is an angular position in a direction in which the imaging unit will tilt due to its own weight when the tilt axis motor 74 is de-energized while maintaining the current tilt angle position (hereinafter referred to as a predicted rotation direction). As a result, even if the imaging unit tilts due to its own weight immediately after the tilt axis motor 74 is de-energized and hits a part of the pan-tilt camera 1 (for example, the fixed base 4), the impact is mitigated.

[0051] From the viewpoint of preventing tilt rotation immediately after power cut-off, the retract angle position θ is preferably a tilt angle position where the static torque TX is equal to or less than the threshold torque TH (threshold or less). To achieve this, the CPU 71 changes the tilt angle of the imaging unit and executes a process of monitoring the static torque TX at the changed tilt angle one or more times. For example, the CPU 71 gradually increases the tilt rotation amount in the predicted rotation direction and detects the static torque TX at each tilt angle. Then, if the CPU 71 can find an angle position where the static torque TX≦threshold torque TH, the angle position is set as the retract angle position.

[0052] In this way, by tilting to an angle position where the stationary torque TX≦threshold torque TH before the power is cut off, the rotor will not tilt in the predicted rotation direction immediately after the power is cut off, thereby avoiding a collision.

[0053] In a configuration in which the tiltable angle range of the imaging unit is restricted, there may be no angle position where the stationary torque TX is less than or equal to the threshold torque TH. In that case, the largest possible angle position within the restricted angle range may be set as the retract angle position.

[0054] Alternatively, the retract angle position may be a predetermined angle position. In this case, the retract angle positions are stored for both tilt rotation directions, and the retract angle position in the predicted rotation direction determined from the sign of the stationary torque TX is used.

[0055] Even if the threshold torque TH<stationary torque TX state is maintained after the evacuation operation, the amount of tilt in the predicted rotation direction immediately after the power cutoff is reduced by even a small amount of tilt in the predicted rotation direction compared to before the power cutoff. Therefore, the impact of the collision is mitigated.

[0056] 8 is a flowchart of the process when power is turned off. This process is realized by the CPU 71 expanding a program stored in the ROM 72 into the RAM 73 and executing it. This process is started when an instruction to turn off the power to the tilt axis motor 74 is input. The instruction to turn off the power is issued by an instruction to end shooting, such as turning off the power of the pan-tilt camera 1, for example, but is not limited to this.

[0057] In step S101, the CPU 71 detects the stationary torque TX based on the value of the current flowing through the tilt axis motor 74 with the tilt rotation stopped at the current tilt angle position. In step S102, the CPU 71 determines whether or not the threshold torque TH<stationary torque TX holds. If the CPU 71 determines that the stationary torque TX≦threshold torque TH holds, there is no risk of tilt rotation even if the power supply is cut off, so the process proceeds to step S103. In step S103, the power supply to the tilt axis motor 74 is cut off (turned off), and this process ends.

[0058] If it is determined in step S102 that the threshold torque TH<stationary torque TX holds, the CPU 71 proceeds to step S104 and executes the above-mentioned notification process. For example, a warning is displayed that tilt rotation will occur due to power cutoff (FIG. 6).

[0059] In step S105, the CPU 71 stores the current tilt angle position in the memory 76. In step S106, the CPU 71 accepts a selection of whether to perform automatic return from the user, and determines whether to perform automatic return based on the content of the acceptance. In this acceptance process, for example, a mode in which options are displayed on the display panel 11 and the user is allowed to select is considered. The automatic return is a process in which the imaging unit is tilted (returned) to the stored tilt angle position before the retraction when power supply is resumed.

[0060] If the received content indicates that automatic return is to be performed, the CPU 71 proceeds to step S107, and if the received content does not indicate that automatic return is to be performed, the CPU 71 proceeds to step S108. In step S107, the CPU 71 sets the return flag to "1" to record that automatic return is to be applied. After that, the CPU 71 proceeds to step S108.

[0061] In step S108, the CPU 71 tilts the imaging unit to the retract angle position described above, and then cuts off power to the tilt axis motor 74 in step S103.

[0062] Thereafter, when an instruction to start energizing the tilt axis motor 74 is input by an instruction to start shooting, such as turning on the power of the pan-tilt camera 1, a process not shown resumes energization to the tilt axis motor 74. At that time, the CPU 71 refers to the restoration flag, and executes the automatic restoration process when the energization is resumed, on condition that automatic restoration is selected (return flag=1).

[0063] By executing the automatic return, the imaging unit is tilted and rotated to the stored tilt angle position, and the tilt angle before the movement to the retracted angle position is reproduced. Therefore, by selecting the automatic return, the user does not need to perform the tilt rotation operation again, and the complexity is reduced. On the other hand, there are cases where the interchangeable lens is replaced after the power is turned off. In such a case, the automatic return is not appropriate, so the user can simply select not to automatically return.

[0064] According to this embodiment, when the stationary torque TX applied to the tilt axis motor 74 while the imaging unit is stationary in the tilt direction during energization of the tilt axis motor 74 exceeds the threshold torque TH, a notification process is executed before cutting off the energization. This allows the user to recognize that the imaging unit will tilt, making it possible to prevent the imaging unit from tilting unintentionally when the energization is cut off.

[0065] Furthermore, since the threshold torque TH is set to a value smaller than the torque TY, the notification process can be executed in a situation where a tilt rotation is predicted to occur due to a current cutoff.

[0066] Also, since the stationary torque TX is detected based on the value of the current flowing through the tilt axis motor 74, it is possible to avoid a complicated configuration. Note that a mechanism for detecting the stationary torque TX may be provided separately.

[0067] In addition, since the CPU 71 tilts the imaging unit to a retract angle position before cutting off the power, it is possible to avoid a collision due to tilt rotation immediately after cutting off the power, or to reduce the amount of tilt rotation immediately after cutting off the power, thereby mitigating the impact.

[0068] In addition, in the automatic return, the CPU 71 stores the tilt angle position of the imaging unit before tilting the imaging unit to the retracted angle position, and when the power supply is resumed, tilts the imaging unit to the stored tilt angle position. Furthermore, whether or not to perform the automatic return can be selected. Therefore, the usability for the user is improved.

[0069] The present invention is not limited to the case where the pan-tilt camera 1 is a stationary camera, but can also be applied to the case where it is suspended as shown in FIGS.

[0070] Fig. 9 is a perspective view of the pan-tilt camera 1 suspended from a ceiling. Fig. 10 is a side view of the pan-tilt camera 1 after the center of gravity has been adjusted, and corresponds to Fig. 4. Fig. 11 is a diagram showing a state in which the zoom group 14 has moved toward the subject in the optical axis direction from the state shown in Fig. 10, and corresponds to Fig. 5. Fig. 12 is a side view of the pan-tilt camera 1 after the retraction operation, and corresponds to Fig. 7.

[0071] Even when the camera is installed on a ceiling, the power-off process (FIG. 8) is applied. An acceleration sensor (not shown) may be provided in the imaging unit support device to determine whether the camera is installed on a ceiling. The CPU 71 may set different retraction angle positions when the imaging unit support device is in a stationary state and when the imaging unit is in a ceiling-suspended state. Since the constraints on the tiltable angle range of the imaging unit may differ between the stationary state and the ceiling-suspended state, there is an advantage in applying retraction angle positions according to each state. When the camera is installed on a ceiling, the notification process in step S104 may be different from that when the camera is installed on a ceiling. For example, when the camera is installed on a floor, a warning is displayed that the camera will fall when the power is turned off as shown in FIG. 6, but when the camera is installed on a ceiling, the camera will not fall when the power is turned off, so a different display is displayed. When the camera is installed on a ceiling, for example, a warning is displayed that the lens unit 9 will rotate in the direction of gravity when the power is turned off.

[0072] Second embodiment The second embodiment of the present invention is different from the first embodiment in the process performed when power is turned off, but the other configurations are the same.

[0073] 13 is a flowchart of the power-off process. The execution body and start conditions of this process are the same as those of the power-off process shown in FIG.

[0074] 13, steps S201 to S204, S206, and S207 are similar to steps S101 to S104, S106, and S107 in FIG.

[0075] In this embodiment, the CPU 71 moves the zoom group 14 (zoom lens) or the focus group 15 (focus lens) in the imaging unit to a retracted position in the optical axis direction before cutting off the power supply to the tilt axis motor 74. Note that the lens to be retracted may be either the zoom group 14 or the focus group 15.

[0076] The retracted position is a position where the center of gravity of the imaging unit is closer to the tilt center compared to before the movement of the zoom group 14 or the focus group 15 (hereinafter referred to as the zoom group 14, etc.). The CPU 71 changes the position of the zoom group 14, etc. in the optical axis direction and executes a process of monitoring the static torque at the changed position one or more times. For example, the CPU 71 moves the zoom group 14, etc. stepwise in the optical axis direction in a direction where the center of gravity of the imaging unit is closer to the tilt center, and detects the static torque TX at each position. Then, if the CPU 71 can find a position where the static torque TX≦threshold torque TH, the CPU 71 sets that position as the retracted position.

[0077] In step S205, the CPU 71 stores the encoder coordinates measured by an encoder (not shown) in the memory 76. As described above, the positions of the zoom group 14 and the like in the optical axis direction change by driving the follow focus 10 (lens driving unit). The encoder coordinates are values ​​that indicate the driving position of the follow focus 10. Therefore, the CPU 71 stores the driving position of the follow focus 10 before the zoom group 14 and the like move to the retracted position in the memory 76 as the position before the zoom group 14 and the like move to the retracted position.

[0078] In step S208, the CPU 71 controls the follow focus driving unit 77 to drive the follow focus 10 to a driving position that moves the zoom group 14 and the like to the retracted position described above.

[0079] In this embodiment, the automatic return process is executed when the power supply is resumed on the condition that automatic return is selected (return flag = 1). At that time, the CPU 71 returns the drive position of the follow focus 10 to the encoder coordinates stored in the memory 76, thereby returning the zoom group 14 and the like to the positions before the movement.

[0080] According to this embodiment, it is possible to achieve the same effect as the first embodiment in terms of preventing the imaging unit from tilting unintentionally when the power supply is cut off.

[0081] Furthermore, if the automatic return process is not applied, the angle of view and focus of the image will be shifted when the power is turned back on, and the user will have to do more work to readjust the zoom and focus. However, by selecting the automatic return process, such inconveniences can be eliminated.

[0082] In the above-described embodiments, the notification process is executed only when it is necessary to cut off the power supply, but the present invention is not limited to this. For example, the notification that there is a risk of tilt rotation due to the power supply being turned off may be executed at all times.

[0083] In the above embodiments, the retraction angle position or the retraction operation to the retraction position is not essential. The user can be alerted by simply executing the notification process. Even in this case, there is an advantage in that the user can take measures such as manually changing the tilt angle.

[0084] In each of the above embodiments, it is not essential to provide the option of automatic return, and automatic return may be executed across the board. However, it is not essential to provide the automatic return process itself.

[0085] In each of the above-described embodiments, the imaging unit is not limited to a lens-exchangeable configuration, and may be an imaging device with an integrated lens.

[0086] In the above-described embodiments, the imaging unit is detachable from the imaging unit support device, but this is not limited to the above. That is, the imaging unit and the imaging unit support device integrated together (i.e., the pan-tilt camera 1) may be called the imaging unit support device of the present invention, or may be called the imaging device.

[0087] In each of the above-described embodiments, accessories other than the imaging unit may be detachably attached to the imaging unit support device of the present invention.

[0088] (Other embodiments) The present invention can also be realized by supplying a program that realizes one or more of the functions of the above-mentioned embodiments to a system or device via a network or a non-transitory storage medium, and having one or more processors of a computer in the system or device read and execute the program. The above program and the storage medium that stores the above program constitute the present invention. The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more of the functions.

[0089] Although the present invention has been described in detail based on the preferred embodiments, the present invention is not limited to these specific embodiments, and various forms within the scope of the gist of the present invention are also included in the present invention. Parts of the above-described embodiments may be combined as appropriate.

[0090] The disclosure of this embodiment includes the following configurations (and methods). (Configuration 1) A support part that supports an imaging part so as to be rotatable in a tilt direction; a motor that rotates the imaging unit in the tilt direction; a detection unit that detects a stationary torque applied to the motor while the imaging unit is stationary in the tilt direction when the motor is energized; and a control unit that performs a notification process when the stationary torque detected by the detection unit exceeds a threshold value. (Configuration 2) The imaging unit support device according to configuration 1, wherein the control means executes the notification process before cutting off power to the motor. (Configuration 3) The detection means detects the stationary torque in response to an instruction to cut off current supply, 3. The imaging unit support device according to configuration 2, wherein the control means cuts off power supply to the motor in response to the instruction. (Configuration 4) An imaging unit support device described in any one of configurations 1 to 3, characterized in that the threshold value is set to a value smaller than the minimum torque value at which tilt rotation occurs when the motor is not energized, assuming that the center of gravity of the imaging unit and the tilt center coincide. (Configuration 5) The imaging unit support device according to any one of configurations 1 to 4, wherein the detection means detects the stationary torque based on a value of a current flowing through the motor. (Configuration 6) The imaging unit support device described in any one of configurations 1 to 5, characterized in that when cutting off power to the motor, the control means tilts and rotates the imaging unit to a retract angle position before cutting off power to the motor. (Configuration 7) The imaging unit support device according to configuration 6, wherein the retracted angular position is an angular position in a direction in which the imaging unit rotates under its own weight when the motor is de-energized. (Configuration 8) The imaging unit support device described in configuration 6 or 7, characterized in that the control means performs a process of changing the tilt angle of the imaging unit and monitoring the stationary torque at the changed tilt angle one or more times before cutting off the power supply to the motor, and if there is a tilt angle position at which the stationary torque is equal to or less than the threshold value, sets that tilt angle position as the retracted angle position. (Configuration 9) The imaging unit support device according to configuration 6, wherein the retracted angular position is a predetermined angular position. (Configuration 10) The imaging unit support device according to configuration 9, wherein the control means causes the predetermined angular position to differ depending on whether the imaging unit support device is in a stationary state or a suspended state. (Configuration 11) The imaging unit support device described in any one of configurations 6 to 10, characterized in that the control means stores the angular position of the imaging unit before tilting the imaging unit to the retracted angle position, and tilts the imaging unit to the stored angular position when power is supplied to the motor again. (Configuration 12) The imaging unit support device described in Configuration 11, characterized in that when the imaging unit is tilted to the retracted angle position, the control means accepts a selection of whether or not to automatically return the imaging unit, and, if automatic return is selected, tilts the imaging unit to the stored angle position when power is resumed to the motor. (Configuration 13) An imaging unit support device described in any one of configurations 1 to 5, characterized in that when cutting off power to the motor, the control means moves a zoom lens or focus lens in the imaging unit to a retracted position in the optical axis direction before cutting off power to the motor. (Configuration 14) The imaging unit support device according to configuration 13, wherein the retracted position is a position where the center of gravity of the imaging unit is closer to a tilt center than before the movement. (Configuration 15) The image capture unit support device described in Configuration 13 or 14, characterized in that the control means performs a process of changing the position of the zoom lens or the focus lens in the optical axis direction and monitoring the static torque at the changed position one or more times, and sets the position where the static torque is below the threshold value as the evacuation position. (Configuration 16) An imaging unit support device described in any one of configurations 13 to 15, characterized in that the control means memorizes the position of the zoom lens or the focus lens before it was moved to the retracted position, and when power is applied to the motor again, returns the zoom lens or the focus lens to the memorized position before it was moved. (Configuration 17) The imaging unit support device described in Configuration 16, characterized in that when the zoom lens or the focus lens is moved to the retracted position, the control means accepts a selection of whether or not to automatically return, and, provided that automatic return is selected, returns the zoom lens or the focus lens to the memorized position when power is resumed to the motor. (Configuration 18) The position of the zoom lens or the focus lens in the optical axis direction is changed by driving a lens driving unit; The imaging unit support device described in configuration 16 or 17, characterized in that the control means stores the drive position of the lens drive unit before the zoom lens or the focus lens is moved to the retracted position as the position of the zoom lens or the focus lens before being moved to the retracted position. (Method 1) A method for controlling an imaging unit support device having a support unit that supports an imaging unit rotatably in a tilt direction and a motor that rotates the imaging unit in the tilt direction, comprising: detecting a stationary torque applied to the motor while the imaging unit is stationary in the tilt direction while the motor is energized; A control method for an imaging unit support device, comprising: executing a notification process when the detected stationary torque exceeds a threshold value. [Explanation of symbols]

[0091] 1 Pan-tilt camera 4 Fixed base 5 Swivel Head 6 Camera section 9 Lens unit 71 CPU 74 Tilt axis motor

Claims

1. a support portion that supports the imaging portion so as to be rotatable in a tilt direction; a motor that rotates the imaging unit in the tilt direction; a detection unit that detects a stationary torque applied to the motor while the imaging unit is stationary in the tilt direction when the motor is energized; and a control unit that performs a notification process when the stationary torque detected by the detection unit exceeds a threshold value.

2. 2. The imaging unit support device according to claim 1, wherein the control means executes the notification process before cutting off power to the motor.

3. The detection means detects the stationary torque in response to an instruction to cut off current supply, 3. The imaging unit support device according to claim 2, wherein the control means cuts off power supply to the motor in response to the instruction.

4. 2. The imaging unit support device according to claim 1, wherein the threshold value is set to a value smaller than the minimum torque value at which tilt rotation occurs when the motor is not energized, assuming that the center of gravity of the imaging unit and the tilt center coincide with each other.

5. 2. The imaging unit support device according to claim 1, wherein the detection means detects the stationary torque based on a value of a current flowing through the motor.

6. 2. The imaging unit support device according to claim 1, wherein the control means, when cutting off the power supply to the motor, tilts the imaging unit to a retract angle position before cutting off the power supply to the motor.

7. 7. The imaging unit support device according to claim 6, wherein the retracted angular position is an angular position in a direction in which the imaging unit rotates under its own weight when the motor is de-energized.

8. 7. The imaging unit support device according to claim 6, wherein the control means performs a process of changing the tilt angle of the imaging unit and monitoring the stationary torque at the changed tilt angle one or more times before cutting off the power supply to the motor, and if there is a tilt angle position at which the stationary torque is equal to or less than the threshold value, the tilt angle position is set as the retracted angle position.

9. 7. The imaging unit support device according to claim 6, wherein the retracted angular position is a predetermined angular position.

10. 10. The imaging unit support device according to claim 9, wherein the control means changes the predetermined angular position depending on whether the imaging unit support device is in a stationary state or a ceiling-suspended state.

11. 7. The imaging unit support device according to claim 6, wherein the control means stores an angular position of the imaging unit before tilting the imaging unit to the retracted angular position, and tilts the imaging unit to the stored angular position when power is supplied to the motor again.

12. The imaging unit support device according to claim 11, characterized in that the control means, when tilting the imaging unit to the retracted angle position, accepts a selection of whether or not to automatically return the imaging unit to the retracted angle position, and, on the condition that automatic return is selected, tilts the imaging unit to the stored angle position when power is resumed to the motor.

13. The imaging unit support device according to claim 1, characterized in that, when cutting off power to the motor, the control means moves a zoom lens or a focus lens in the imaging unit to a retracted position in the optical axis direction before cutting off power to the motor.

14. 14. The imaging unit support device according to claim 13, wherein the retracted position is a position where the center of gravity of the imaging unit is closer to a tilt center than before the movement.

15. The imaging unit support device described in claim 13, characterized in that the control means performs a process of changing the position of the zoom lens or the focus lens in the optical axis direction and monitoring the stationary torque at the changed position one or more times, and sets the position where the stationary torque is below the threshold value as the evacuation position.

16. The imaging unit support device of claim 13, characterized in that the control means stores the position of the zoom lens or the focus lens before it is moved to the retracted position, and when power is supplied to the motor again, returns the zoom lens or the focus lens to the stored position before it is moved.

17. The imaging unit support device of claim 16, characterized in that the control means accepts a selection of whether or not to automatically return the zoom lens or the focus lens when moving the zoom lens or the focus lens to the retracted position, and, if automatic return is selected, returns the zoom lens or the focus lens to the stored position when power is resumed to the motor.

18. a position of the zoom lens or the focus lens in the optical axis direction is changed by driving a lens driving unit; The imaging unit support device of claim 16, characterized in that the control means stores the drive position of the lens drive unit before the zoom lens or the focus lens is moved to the retracted position as the position of the zoom lens or the focus lens before being moved to the retracted position.

19. A control method for an imaging unit support device having a support section that rotatably supports an imaging unit in a tilt direction and a motor that rotates the imaging unit in the tilt direction, comprising: detecting a stationary torque applied to the motor while the imaging unit is stationary in the tilt direction while the motor is energized; A control method for an imaging unit support device, comprising: executing a notification process when the detected stationary torque exceeds a threshold value.

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