Imaging device, imaging method, and computer program

Abstract

The present invention provides an imaging device that reduces camera head vibration while achieving power savings for the motor. [Solution] The imaging device is characterized by comprising: a camera head; a motor for changing the direction of the camera head; a first vibration detection means for detecting vibrations of the camera head; and an excitation control means for changing the motor from the de-excited state to the excited state when the vibration detected by the first vibration detection means is determined to be greater than a predetermined value while the motor is in a de-excited state.

Description

Technical Field

[0001] The present invention relates to an imaging device, an imaging method, a computer program, and the like.

Background Art

[0002] There is known an imaging device capable of changing the imaging direction by changing the orientation of a camera head by means of a pan-tilt drive unit. These pan-tilt drive units are composed of actuators that can be controlled by an electric signal such as a motor, and when not driven, the motor can be controlled to change the holding torque.

[0003] For example, Patent Document 1 describes a configuration in which, prior to power-off of an imaging device provided with a pan-tilt drive unit and a pan-tilt control unit, the drive unit is controlled so that the orientation of the imaging unit becomes a predetermined direction.

[0004] Also, for example, Patent Document 2 discloses a configuration for calculating the orientation of a camera head using an acquired value from a gyro sensor.

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 conventional technology, when the motor is non-energized (non-excited), depending on the installation orientation of the imaging device, the camera head may move greatly like a pendulum due to the influence of an earthquake or the like, resulting in damage to the imaging device itself or damage to the installation part such as the floor or ceiling.

[0007] Therefore, the object of the present invention is to provide an imaging device that can reduce camera head shaking while achieving power saving for the motor. [Means for solving the problem]

[0008] To achieve the above objective, the one-sided imaging device of the present invention is Camera head and, A motor for changing the direction of the camera head, A first shake detection means for detecting the shaking of the camera head, When the motor is in a de-excited state, the first vibration detection means determines that the vibration detected is greater than a predetermined value, and the excitation control means changes the motor from the de-excited state to an excited state. It is characterized by having the following features. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an imaging device that can reduce camera head shaking while achieving power saving for the motor. [Brief explanation of the drawing]

[0010] [Figure 1] This is a functional block diagram showing an example configuration of the imaging device according to Embodiment 1. [Figure 2] (A) and (B) are diagrams illustrating the mechanical configuration of the imaging device according to Embodiment 1 and an example of the operation of the pan-tilt drive unit. [Figure 3] This flowchart shows an example of the process for changing the excitation state in the imaging method according to Embodiment 1. [Figure 4] This is a diagram to explain how camera head shake detection works. [Figure 5] This flowchart shows an example of the process for returning to a de-excited state in the imaging method according to Embodiment 1. [Figure 6] This is a diagram illustrating an example of determining the shaking of an imaging device according to Embodiment 1. [Figure 7]It is a functional block diagram showing a configuration example of an imaging device according to Embodiment 2. [Figure 8] It is a flowchart showing an example of a change process to an excitation state in an imaging method according to Embodiment 2. [Figure 9] It is a functional block diagram showing a configuration example of an imaging device according to Embodiment 3.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments. In each figure, the same members or elements are denoted by the same reference numerals, and duplicate explanations are omitted or simplified.

[0012] <Embodiment 1> FIG. 1 is a functional block diagram showing a configuration example of an imaging device according to Embodiment 1. Note that a part of the functional blocks shown in FIG. 1 is realized by causing a CPU or the like as a computer included in the imaging device, which is not shown, to execute a computer program stored in a memory as a storage medium, which is not shown.

[0013] However, part or all of them may be realized by hardware. As the hardware, a dedicated circuit (ASIC) or a processor (reconfigurable processor, DSP) or the like can be used.

[0014] Also, each of the functional blocks shown in FIG. 1 does not have to be built in the same housing, and may be constituted by separate devices connected to each other via a signal path. Note that the above description regarding FIG. 1 also applies to FIGS. 7 and 9 in the same manner.

[0015] The imaging device 100 is connected to an information processing device (client device) 160 via a network 150 so as to be able to communicate with each other. A user can transmit various camera control commands to the imaging device 100 via the information processing device 160.

[0016] The imaging unit 101 is composed of an imaging lens including a focus lens, a zoom lens, etc., an imaging element, and a mechanical drive system and a circuit for driving them. The imaging lens forms a subject image on the light receiving surface of the imaging element, and the imaging element generates an electrical signal indicating the subject image.

[0017] The pan drive unit 102 is composed of a mechanical drive system for performing a pan operation and a motor for pan drive, and is controlled by the pan-tilt control unit 105. The tilt drive unit 103 is composed of a mechanical drive system for performing a tilt operation and a motor for tilt drive, and is controlled by the pan-tilt control unit 105.

[0018] The detailed configuration of the pan drive unit 102 and the tilt drive unit 103 will be described later using FIG. 2. Hereinafter, the motor for pan drive will be referred to as the pan motor, and the motor for tilt drive will be referred to as the tilt motor. The pan motor and the tilt motor function as motors for changing the direction of the camera head, and the above motors include the pan motor or the tilt motor.

[0019] The image processing unit 104 performs image processing such as noise removal and gamma correction on the electrical signal generated by the imaging unit 101, generates image data, and transmits it to the system control unit 107. Also, it receives a control signal from the system control unit 107 for the imaging unit 101 and the image processing unit 104, and controls the imaging unit 101 and the image processing unit 104 accordingly.

[0020] That is, for example, when receiving an instruction for image quality adjustment from the system control unit 107, the image processing unit 104 adjusts the image quality. Also, when receiving an instruction for changing the zoom position or the focus position from the system control unit 107, the imaging unit 101 is controlled so that the focus lens and the zoom lens are at positions corresponding to the received change instruction.

[0021] The pan-tilt control unit 105 processes instructions related to pan-tilt control. For example, based on an instruction received from the system control unit 107, it controls the driving amount, speed, acceleration and deceleration of the pan motor and the tilt motor, and performs initialization operations, etc.

[0022] Furthermore, the pan-tilt control unit 105 functions as an excitation control means. That is, it changes the excitation state of the pan motor and tilt motor based on instructions received from the parameter processing unit 106.

[0023] For example, if the pan motor and tilt motor are stepping motors, and the pan / tilt control unit 105 is a motor driver, the excitation state can be changed by the motor driver controlling the current value supplied to the stepping motor. In the following, the state in which no power is supplied to the motor will be referred to as the de-excited state, and the state in which power is supplied will be referred to as the excited state.

[0024] Here, the system control unit 107 and the parameter processing unit 106 issue instructions to change the current value to the motor driver. Furthermore, the motor driver can improve the holding torque by energizing the stepping motor, thereby enabling it to maintain the orientation of the camera head 204 (Figure 2), which is part of the imaging device 100.

[0025] The parameter processing unit 106 calculates the angular displacement by performing an integral operation on the angular velocity acquired by the first vibration detection unit 109. It also uses the calculated angular displacement to determine whether the camera head 204 has moved. In other words, the excitation control means determines the magnitude of the camera head's vibration based on the camera head's angular displacement.

[0026] Further details on the shake detection will be described later in Figure 4. If the parameter processing unit 106 determines that the camera head 204 is moving, it instructs the pan / tilt control unit 105 to change the excitation state.

[0027] Furthermore, the parameter processing unit 106 calculates the coordinate displacement by performing an integral calculation on the acceleration acquired by the first vibration detection unit 109. It also uses the calculated coordinate displacement to determine whether the imaging device 100 has moved.

[0028] Details of the determination will be described later in Figure 6. If the parameter processing unit 106 determines that the imaging device 100 or camera head 204 is not moving or that shaking is not continuing, it instructs the pan / tilt control unit 105 to change to a de-excited state. The parameter processing unit 106 also functions as a means for determining shaking.

[0029] The system control unit 107 has a built-in CPU and other components, and functions as a control means that controls the operation of each part of the imaging device 100 based on computer programs stored in the memory, which serves as a storage medium. The system control unit 107 also distributes image data generated by the image processing unit 104 to the information processing device 160 via the communication unit 108.

[0030] Furthermore, the system control unit 107 analyzes the camera control commands transmitted from the information processing device 160 via the communication unit 108 and transmits the analysis results to each part of the imaging device 100. For example, instructions related to image processing and the imaging unit 101 are transmitted to the image processing unit 104, and instructions related to pan-tilt control are transmitted to the pan-tilt control unit 105.

[0031] Furthermore, the system control unit 107 functions as a mode change mechanism. Specifically, when it receives a command to transition to standby mode, it transmits instructions to the image processing unit 104 and the pan / tilt control unit 105 to enter standby mode. Also, when the system control unit 107 receives a command to return from standby mode, it transmits instructions to the image processing unit 104 and the pan / tilt control unit 105 to return to standby mode.

[0032] Here, the standby state mentioned above refers to a de-energized state in which no power is supplied to the pan motor and tilt motor. However, it is not limited to this; for example, it may also refer to an energy-saving state in which a small current is supplied to the pan motor and tilt motor compared to the normal operating mode.

[0033] In other words, the de-energized state in this embodiment includes a state in which a weak current is supplied to the motor, and includes a state in which the amount of current supplied to the motor is sufficiently small compared to the energized state. That is, it is sufficient that the relationship between the energized state and the de-energized state is such that the amount of current is much greater than that of the energized state.

[0034] Alternatively, in standby mode, in addition to the pan motor and tilt motor, the system may be configured so that power is not supplied to at least some of the imaging unit 101, image processing unit 104, pan / tilt control unit 105, system control unit 107, and power supply unit (not shown).

[0035] In that case, if the communication unit 108 receives a command to return from standby, or if the parameter processing unit 106 sends an instruction to the pan-tilt control unit 105, power is restored to the previously de-energized parts.

[0036] The communication unit 108 receives camera control commands transmitted from the information processing device 160 and transmits them to the system control unit 107. It also transmits image data generated by the image processing unit 104 and responses to camera control commands to the information processing device 160.

[0037] The first shake detection unit 109 functions as a first shake detection means for detecting camera head shake, and detects the angular velocity and acceleration of the camera head 204. The first shake detection unit 109 is composed of, for example, a gyro sensor or a motion sensor, but may also be composed of other sensors such as a distance measuring sensor or a rotary encoder.

[0038] Furthermore, the first shake detection unit 109 may also detect the shaking of the camera head 204 based on the motion vector of the image captured by the imaging unit 101.

[0039] Furthermore, if the first vibration detection unit 109 is configured with, for example, another sensor, the angular displacement and coordinate displacement are calculated by performing calculations in the parameter processing unit 106 as needed. As an example, a configuration in which a gyro sensor or motion sensor is provided on the camera head 204 will be described later in Figure 2.

[0040] Furthermore, the imaging device 100 in this embodiment is not limited to the configuration shown in Figure 1. For example, the imaging device 100 may be provided with video output terminals such as SDI (Serial Digital Interface) or HDMI (High-Definition Multimedia Interface), as well as audio input / output units and external device input / output units.

[0041] Furthermore, the communication unit 108 may be connected via wired or wireless connection. Also, instead of being connected to the network 150, the communication unit 108 may be connected to a device such as the information processing device 160 via serial communication or the like.

[0042] Figures 2(A) and 2(B) are diagrams illustrating the mechanical configuration of the imaging device according to Embodiment 1 and an example of the operation of the pan-tilt drive unit. Figure 2(A) is a view of the mounted imaging device 100 from above, and Figure 2(B) is a view from the side.

[0043] In Figures 2(A) and (B), 201 is the bottom case, 202 is a turntable that functions as a support for the camera head support column 203 (described later), 203 is a support column that functions as a support for the camera head 204, and 204 is a camera head that houses the imaging unit 101. The imaging device 100 is composed of 201 to 204, etc.

[0044] In Figure 2(B), the first vibration detection unit 109 is located outside the camera head 204, but it may also be installed inside.

[0045] Next, the operation of the pan-tilt drive unit will be explained with reference to Figures 2(A) and (B). In Figure 2(A), the clockwise direction is the positive direction of the pan angle and the counterclockwise direction is the negative direction of the pan angle, with respect to the vertical axis perpendicular to the plane of the paper. In Figure 2(B), the counterclockwise direction is the positive direction of the tilt angle and the clockwise direction is the negative direction of the tilt angle, with respect to the axis perpendicular to the plane of the paper.

[0046] Figure 2(A) shows the pan drive direction, and the pan drive unit 102 has a bottom case 201 and a turntable 202, and the turntable 202 rotates about a vertical axis perpendicular to the plane of the paper. The pan drive unit 102 of this embodiment can rotate from -170 degrees to +170 degrees as shown in the figure.

[0047] Figure 2(B) shows the tilt drive direction. The tilt drive unit 103 rotates the camera head 204 around the X-axis in Figure 2(A) relative to the camera head support column 203 mounted on the turntable 202, for example, by a tilt motor provided inside the camera head 204. The tilt drive unit 103 in this embodiment can rotate from -20 degrees to +180 degrees as shown in the figure.

[0048] As described above, the imaging device 100 of this embodiment can change the shooting direction and capture a wide area by rotating the camera head 204 in the pan and tilt directions. However, the imaging device 100 in this embodiment is not limited to the configuration shown in Figure 2. For example, it may be possible to drive it endlessly 360 degrees in the pan direction. Furthermore, it may be possible to drive it over an even wider angle in the tilt direction.

[0049] The first shake detection unit 109 is installed on the camera head 204 and detects the angular velocity of the camera head 204 in the yaw direction and the pitch direction. Here, the yaw direction (hereinafter referred to as the pan direction) is the direction of rotation around the Y axis in Figure 2(B), and the pitch direction (hereinafter referred to as the tilt direction) is the direction of rotation around the X axis in Figure 2(A).

[0050] In Figures 2(A) and (B), the X, Y, and Z axes represent the output axes of the first shake detection unit 109. For example, the angular velocity in the tilt direction can be detected by the X axis of the first shake detection unit 109, and the angular velocity in the pan direction can be detected by the Y axis of the first shake detection unit 109. Furthermore, the first shake detection unit 109 can also detect the acceleration of the imaging device 100 in the X, Y, and Z axis directions.

[0051] Figure 3 is a flowchart showing an example of the process for changing the excitation state in the imaging method according to Embodiment 1. The CPU and other components of the system control unit 107 execute a computer program stored in memory, and the parameter processing unit 106 sequentially performs the operations of each step in the flowchart of Figure 3.

[0052] The flowchart in Figure 3 shows a sequence that is performed when the imaging device 100 is in standby mode and the pan motor or tilt motor is de-energized (PT de-energized state). In step S301, the sequence in the parameter processing unit 106 is started. Note that PT stands for pan or tilt.

[0053] In step S302, the first shake detection unit 109 acquires the angular velocity of the camera head 204 in the pan and tilt directions. At this time, the parameter processing unit 106 performs an integral calculation on the acquired angular velocity to calculate the angular displacement. Here, step S302 functions as the first shake detection step for detecting the shaking of the camera head.

[0054] Furthermore, the angle of the camera head 204 at the start of the processing flow shown in Figure 3 is used as the reference angle, and the pan angle (hereinafter referred to as the pan angle) and tilt angle (hereinafter referred to as the tilt angle) of the camera head 204 are calculated from the calculated angular displacement.

[0055] In step S303, it is determined whether or not there is movement of the camera head 204. That is, for example, it is determined whether or not there is movement of the camera head 204 based on at least one of (1) and (2) below.

[0056] (1) Determine "Yes" if the angular displacement in the pan or tilt direction is greater than a predetermined threshold.

[0057] (2) The number of times the above threshold is exceeded is counted, and if it exceeds a predetermined number of times, it is determined to be Yes. That is, the excitation control means determines the magnitude of the shaking based on whether the number of times the angular displacement of the camera head exceeds a predetermined threshold is equal to or greater than the predetermined threshold.

[0058] Furthermore, the user may be able to select in advance, using the information processing device 160, which of the above methods (1) and (2) to perform. That is, the information processing device 160 transmits a control signal to the imaging device 100 via the network 150 for selecting the determination means. This control signal is received by the parameter processing unit 106 via the communication unit 108 and the system control unit 107.

[0059] The parameter processing unit 106 performs a determination in step S303 in response to the received control signal. If the determination in step S303 is Yes, the process proceeds to step S304. If the determination in step S303 is No, the process from step S302 is repeated, and periodic processing is performed at an arbitrary interval.

[0060] Figure 4 is a diagram illustrating the determination of camera head 204 shaking, and Figure 4 will be used to explain in detail the determinations in (1) and (2) above.

[0061] In the graph shown in Figure 4, the vertical axis represents, for example, the tilt angle, and the horizontal axis represents time. Here, the value of angle θ used for the determination is a relative value from the tilt angle at the start of the de-energized state of the tilt motor. For example, if the tilt angle at the start of the de-energized state is as shown in Figure 2(B), then +90° is used as the reference angle, and angle θ is the relative value from that angle.

[0062] The following provides a detailed explanation of the determination method in (1) above. In the determination in (1) above, thresholds θα and θβ are used to determine whether θα < θ < θβ or not. If it is determined that θα < θ < θβ is not true even once, then in step S303, it is determined that there is movement and the result is Yes.

[0063] In the example shown in Figure 4, the threshold θα is below the threshold at T1 after the standby start (t0), and this triggers a transition to S304. When using this determination method, a determination can be made more quickly compared to other determination methods, so if the camera head 204 shakes, it is possible to quickly transition to step S304.

[0064] Next, the determination method for (2) above will be explained. In the determination for (2) above, for example, the determination of θα < θ < θβ is made, and the number of times N is determined not to be θα < θ < θβ is counted. For example, if the threshold for the number of times is Nth, and Nth ≤ N, then it is determined that there is movement in step S303, and the program proceeds to step S304.

[0065] For example, if Nth=2, in the example in Figure 4, the number of times it is determined that θα < θ < θβ is not true becomes N=2 in T2, so the process proceeds to step S304 at this point. Note that the threshold values ​​θα and θβ in the determination method in (2) above may be different from the threshold values ​​θα and θβ in the determination in (1) above.

[0066] This detection method makes it possible to eliminate noise caused by unintentional user contact with the camera head 204, for example. Therefore, it is possible to achieve the minimum necessary excitation state changes for the purpose of power saving.

[0067] Furthermore, in order to shorten the time required to change the motor to an excited state, it is desirable for the threshold number Nth to be small. On the other hand, if the imaging device 100 is to be installed in a location where it is likely to be touched by a user or in a place with a lot of vibration, or in a location where it is expected to be used in a place with many external influences, the above threshold Nth can be increased to eliminate the effects of noise.

[0068] Furthermore, the explanation using the pan angle is the same as the explanation using the tilt angle, so the explanation will be omitted. That is, in step S303, if the parameter processing unit 106 determines that either the pan or tilt angle of the camera head 204 is Yes according to the determination method (1) or (2) above, it proceeds to step S304.

[0069] However, the threshold values ​​in the determination methods (1) and (2) above for determining pan angle movement may be different from the threshold values ​​in the determination methods (1) and (2) above for determining tilt angle movement.

[0070] Next, in step S304, it is determined whether there was movement in the pan direction. That is, if the pan angle is determined to be Yes in step S303 using the determination method (1) or (2) above, then it is determined to be Yes in step S304.

[0071] If the result in step S304 is Yes, the process proceeds to step S305, where the pan motor is changed from a de-energized state to an energized state to increase the holding force of the pan motor and reduce camera head shaking. If the result in step S304 is No, the process proceeds to step S306.

[0072] Next, in step S306, it is determined whether there has been movement in the tilt direction. That is, if the tilt angle is determined to be Yes in step S303 using the determination method (1) or (2) above, then it is determined to be Yes in step S306.

[0073] If the result in step S306 is Yes, the process proceeds to step S307, where the tilt motor is changed from a de-energized state to an energized state to increase the holding force of the tilt motor and reduce camera head shaking. If the result in step S306 is No, the process proceeds to step S308.

[0074] In this embodiment, the motors for changing the direction of the camera head include a pan motor and a tilt motor, and the excitation control means determines whether the panning and tilting oscillations of the camera head are greater than predetermined values. As mentioned above, the predetermined values ​​compared with the panning oscillation and the predetermined values ​​compared with the tilting oscillation may be different.

[0075] In step S308, it is determined whether both the pan motor and the tilt motor are energized. In making this determination, if they were energized in steps S305 or S307, a flag is set accordingly.

[0076] If the result in step S308 is "Yes," that is, if both are determined to be in an energized state, the process proceeds to step S309 to enter standby mode (PT energized state). On the other hand, if the result in step S308 is "No," the process from step S302 is repeated. After proceeding to step S309, the process proceeds to step S501 in Figure 5.

[0077] Steps S301 to S309 function as an excitation control step (excitation control means) that changes the motor from a de-excited state to an excited state when it is determined that the vibration detected by the first vibration detection step is greater than a predetermined value while the motor is in a de-excited state.

[0078] As described above, in this embodiment, by individually determining the movement of the pan motor and tilt motor, it is possible to selectively change the excitation state only to the motor in which the camera head 204 is moving in a certain direction.

[0079] This allows for increased holding force only for the motors moving in a particular direction, reducing camera head shake and minimizing the number of motors that need to be excited, thus further enhancing power saving.

[0080] Furthermore, if the result in step S308 is determined to be "No", then in the following steps S302 to S307, in order to reduce the processing load (for power saving purposes), the processing related to the motor for which the above flag is set will be omitted. Then, the processing will be limited to only the motor for which the flag is not set.

[0081] The process of returning the pan motor and tilt motor from their energized state will be explained below using Figures 5 and 6.

[0082] Figure 5 is a flowchart showing an example of the process for returning to the de-excited state in the imaging method according to Embodiment 1. The CPU and other components of the system control unit 107 execute a computer program stored in memory, and the parameter processing unit 106 sequentially performs the operations of each step in the flowchart of Figure 5.

[0083] In step S501, the sequence of the parameter processing unit 106 in this embodiment is started. In this embodiment, the processing flow shown in Figure 5 is performed when the imaging device 100 is in standby mode and both the pan motor and the tilt motor are energized in step S308.

[0084] However, the procedure may be performed if one or more of the pan motors or tilt motors are energized. Figure 5's flowchart illustrates, for example, the case where the tilt motor is energized.

[0085] In step S502, the first vibration detection unit 109 acquires the acceleration of the imaging device 100 in the Z-axis direction. When shaking occurs, such as an earthquake, while the camera head 204 is energized, the entire imaging device 100, including the camera head 204, shakes in accordance with the shaking of the installation site. The first vibration detection unit 109 detects and acquires this shaking as acceleration.

[0086] Here, the parameter processing unit 106 performs an integral calculation on the detected acceleration to calculate the coordinate displacement in the Z-axis direction. Furthermore, using the coordinate position of the imaging device 100 in the Z-axis direction at the start of the processing flow in Figure 5 as the reference position, the amount of vibration (coordinates) of the imaging device 100 in the Z-axis direction is calculated from the calculated coordinate displacement.

[0087] In step S503, a determination is made as follows, for example, to determine whether the shaking of the mounting part of the imaging device 100 is continuing.

[0088] (3) If the Z-axis coordinate displacement remains within the predetermined threshold range even after a predetermined time has elapsed since it last entered the predetermined threshold range, the shaking is not considered to be continuing, and the result is determined to be No. In other words, if the coordinate displacement of the camera head does not exceed the predetermined threshold for a predetermined time, it is determined that the shaking of the camera head is below the predetermined value.

[0089] (4) If the frequency of the vibration decreases, it is determined that the vibration is not continuing and the result is No. That is, when the frequency of the coordinate displacement of the camera head falls below a predetermined threshold, it is determined that the vibration of the camera head is below a predetermined value.

[0090] In principle, the determination is made by implementing the determination method in (3) above, and the determination method in (4) above may be performed in parallel with the determination in (3) in order to further improve the accuracy of the determination. In addition, the user may be able to select in advance using the information processing device 160 whether or not to add the determination method in (4).

[0091] Furthermore, if the result in step S503 is determined to be Yes, the process proceeds to step S504. If the result in step S503 is determined to be No, the process proceeds to step S502. The process from step S502 is repeated, and periodic processing is performed at any desired interval.

[0092] As described above, in the processing flow of FIG. 5, after the excitation control means changes the motor from the non-excited state to the excited state, if it is determined that the shaking is below a predetermined value, the motor is changed from the excited state to the non-excited state. Incidentally, the predetermined value when determining that the shaking is below the predetermined value in FIG. 5 may be different from the predetermined value when it is determined that the shaking is greater than the predetermined value by the first shaking detection step in steps S301 to S309.

[0093] Next, FIG. 6 is a diagram for explaining an example of determining the shake of the imaging device according to Embodiment 1, and the determination methods of (3) and (4) above will be described using FIG. 6. Incidentally, in the graph shown in FIG. 6, the vertical axis represents the coordinate of the Z axis, and the horizontal axis represents time.

[0094] Here, the value of the Z-axis coordinate used for the determination is based on the position of the Z-axis coordinate of the imaging device 100 when step S501 is started, and is a relative value from that reference position.

[0095] Hereinafter, the determination method of (3) above will be described in detail.

[0096] In the determination method of (3) above, a determination is made as to whether Zα < Z < Zβ using Zα and Zβ as threshold values. And finally, if, after a certain time (Tα) has elapsed from the timing (for example, time T3) when the state of Zα < Z < Zβ is reached, the state of Zα < Z < Zβ still remains, it is determined in step S503 that the shaking has not continued (No), and the process proceeds to step S504.

[0097] That is, in the example of FIG. 4, after the start of excitation (t1) of the tilt motor, at time T3, the shaking in the Z-axis direction changes from outside the range of the threshold values Zα to Zβ to within the range, and the parameter processing unit 106 starts counting the elapsed time from T3.

[0098] After that, if the state of Zα < Z < Zβ continues until the elapsed time reaches the certain time Tα, it is determined as No in step S503, and the process proceeds to step S504 to change the tilt motor to the non-excited state.

[0099] Next, the determination method in (4) above will be described. In the determination in (4) above, when the frequency of the shake waveform represented by the Z-axis coordinate in FIG. 6 is f and the threshold value of the shake waveform frequency is Fth, if Fth < f, it is determined as No in step S503. That is, it is determined that the shake is not continuous.

[0100] For example, in FIG. 6, t2 - t1 and t3 - t2 are treated as the period (1 / f) of the shake waveform. The parameter processing unit 106 always monitors this period (1 / f). If 1 / Fth < 1 / f, that is, Fth > f, it is determined as No in step S503. That is, it is determined that the shake is not continuous and the process proceeds to step S504.

[0101] When natural phenomena such as earthquakes occur, the shake of the installation part (the shake of the imaging device 100) is not at a constant frequency but changes from moment to moment. For example, immediately after an earthquake occurs, the frequency is maximum, and after the occurrence, the frequency tends to gradually decrease.

[0102] Also, in an environment where the frequency is low, due to inertia, the vibration of the camera head 204 becomes relatively small. Therefore, by using the determination method as in (4) above, the return from the excited state to the non-excited state can be accelerated, and a more power-saving system can be realized.

[0103] Subsequently, in step S504, the tilt motor is changed from the excited state to the non-excited state. Further, for example, regarding the flag indicating the excited state of the tilt motor set in step S308, it is released at this time. After the implementation of step S504, the process proceeds to step S301.

[0104] Incidentally, although detailed description of the pan motor is omitted, for example, regarding the amount of shake (coordinate) in the X-axis direction, the same determination as for the tilt motor is performed to change from the excited state to the non-excited state. Incidentally, when both the pan motor and the tilt motor are in the excited state, the determination processes for returning each motor to the non-excited state may be performed in parallel.

[0105] As explained in Figures 5 and 6, by returning the energized pan motor and tilt motor to a de-energized state in response to the shaking of the imaging device 100, it becomes possible to achieve power saving of the motors again after the shaking stops.

[0106] As described above, this embodiment makes it possible to realize an imaging device that can reduce the shaking of the lens barrel when shaking occurs, while also achieving power saving of the motor in standby mode.

[0107] <Embodiment 2> Figure 7 is a functional block diagram showing an example configuration of the imaging device according to Embodiment 2. As shown in Figure 7, Embodiment 2 includes a second vibration detection unit 701. The second vibration detection unit 701 is located in the bottom case 201.

[0108] In other words, in Embodiment 2, the bottom case 201 that holds the camera head in a rotatable state is equipped with a second vibration detection means for detecting vibrations of the bottom case 201. In Figure 7, the same reference numerals are used for components that are the same as those described in Figure 1, and their descriptions are omitted.

[0109] Since the imaging device 100 has its bottom case 201 installed on the ceiling or wall, according to this embodiment, if the pan motor or tilt motor is in a de-energized state, it is possible to make a determination that is not affected by the movement of the camera head 204. Therefore, the effects of, for example, accidental movement of the camera head 204 by a user can be ignored, and an even greater power saving effect can be obtained.

[0110] The second vibration detection unit 701 is for detecting the acceleration of the bottom case 201 and is composed of a gyro sensor and a motion sensor. The second vibration detection unit 109 may also detect vibrations of the bottom case 201 based on motion vectors of images captured by the imaging unit 101.

[0111] In this embodiment, the parameter processing unit 106 calculates the coordinate displacement by performing an integral calculation on the acceleration acquired by the second vibration detection unit 701. Furthermore, it uses the calculated coordinate displacement to determine whether or not to change the camera head 204 to an energized state.

[0112] Figure 8 is a flowchart showing an example of the process for changing the excitation state in the imaging method according to Embodiment 2. The process for changing the excitation state in this embodiment will be explained below using Figure 8. The CPU and other components of the system control unit 107 execute a computer program stored in memory, and the parameter processing unit 106 sequentially performs the operations of each step in the flowchart of Figure 8.

[0113] In step S801, the sequence of the parameter processing unit 106 in this embodiment is started. Note that the processing flow in Figure 8 is performed when the imaging device 100 is in standby mode and the pan motor and tilt motor are de-energized, as described in Figure 3.

[0114] In step S802, the acceleration of the bottom case 201 in the X and Z axes is obtained from the second vibration detection unit 701. When the camera head 204 is in a de-excited state and vibrations such as an earthquake occur, the camera head 204 and the bottom case 201 may vibrate independently.

[0115] The second vibration detection unit 701 detects the vibration of the bottom case 201 as acceleration. Here, the parameter processing unit 106 calculates the coordinate displacement in the X and Z directions by performing an integral calculation on the acquired accelerations in the X and Z directions.

[0116] In step S803, it is determined whether or not shaking occurs in the imaging device 100. That is, it is determined whether or not shaking occurs in the mounting part of the bottom case 201 by, for example, the method of (5) or (6) below.

[0117] Determine Yes when the coordinate displacement of the bottom case 201 in the X-axis or Z-axis is greater than the respective predetermined threshold values. (6) Count the number of times exceeding the above threshold value, and determine Yes when it is equal to or more than a predetermined number of times.

[0118] Incidentally, among the methods (5) and (6) above, the user may be able to select in advance which determination process to perform using the information processing apparatus 160. When it is determined Yes in step S303, proceed to step S804. When it is determined No in step S803, repeat the process from step S802 to perform periodic processing at an arbitrary cycle.

[0119] Hereinafter, the determination method of (5) above will be described. In the determination of (5) above, threshold value determination of Xα < X < Xβ (pan direction) and Zα < Z < Zβ (tilt direction) is performed. When X or Z exceeds the respective threshold values (Xα to Xβ, Zα to Zβ), proceed to step S804.

[0120] This determination is the same as the explanation in FIG. 4. Taking the start time of the non-excitation state of the tilt motor and the pan motor as the reference position respectively, perform the above threshold value determination. When X or Z exceeds the respective threshold values, proceed to step S804.

[0121] Incidentally, next, the determination method of (6) in step S803 will be described. In the determination of (6) above, threshold value determination of Xα < X < Xβ and Zα < Z < Zβ is also performed, and the number of times X and Z exceed the respective threshold values (Xα to Xβ, Zα to Zβ) is counted respectively.

[0122] This counting is also performed in the same manner as the determination method of (2) in FIG. 4. When the above number of times for X or Z exceeds the respective predetermined threshold values, proceed to step S804. The processing from step S804 to step S811 is the same as the processing from step S302 to step S309, so detailed explanation is omitted.

[0123] In step S804, the angular velocity of the camera head is obtained, and in step S805, it is determined whether or not there is movement of the camera head 204. The determination method is the same as in step S303. If the determination condition is met, the process proceeds to step S806; otherwise, the process from step S802 is repeated.

[0124] The processing in steps S806 to S810 is the same as in steps S304 to S308, so a detailed explanation is omitted. If the result in step S810 is NO, the processing from step S802 is repeated.

[0125] In other words, in the processing flow shown in Figure 8, when the motor is de-energized, if the output of the first vibration detection means and the second vibration detection means determines that the vibration of the camera head and the bottom case is greater than a predetermined value, the motor is changed from the de-energized state to the energized state. The process of returning the camera head 204 to the de-energized state is carried out in the same manner as described in Figures 5 and 6.

[0126] In other words, the excitation control means of this embodiment changes the motor from an excited state to an excited state, and if it determines that the shaking of the camera head and the bottom case are each below a predetermined value, it changes the motor from an excited state to an excited state. In addition, if the number of times the coordinate displacement of the bottom case exceeds a predetermined threshold within a predetermined time is below a predetermined threshold, it may be determined that the shaking of the bottom case is below a predetermined value.

[0127] <Embodiment 3> Figure 9 is a functional block diagram showing an example configuration of the imaging device according to Embodiment 3. In Embodiment 3, the camera head 204 is configured to be able to be fitted with interchangeable lenses, and by changing the interchangeable lens according to the imaging scene, various specifications related to imaging, such as focus and zoom magnification, can be changed.

[0128] In this configuration, the center of gravity of the camera head 204 changes depending on the type of interchangeable lens, and the effect on the camera head 204's vibration in the event of an earthquake or the like changes. Therefore, in this embodiment, when changing to the excitation state, a determination is made according to the type of interchangeable lens.

[0129] Specifically, the lens mounting detection unit 901 detects the mounting status and type of an interchangeable lens (not shown). When an interchangeable lens is mounted, the lens mounting detection unit 901 reads information such as the type of interchangeable lens written in a ROM or the like provided inside the interchangeable lens, and transmits it to the parameter processing unit 106.

[0130] When the parameter processing unit 106 receives the above information from the lens mounting detection unit 901, it decides which of the determination methods (1) and (2) described above in step S303 to use for determination, depending on the type of interchangeable lens.

[0131] In other words, in this embodiment, when an interchangeable lens is attached, the determination conditions for changing from a non-excited state to an excited state are changed according to the type of interchangeable lens. For example, a case in which the imaging device 100 can be fitted with two types of lenses, a standard lens and a telephoto lens, is described.

[0132] When a telephoto lens is attached to the camera head 204, the center of gravity shifts further forward (to the 0° direction in Figure 2(A)) compared to when a standard lens is attached, because the telephoto lens is heavier. Note that this change in the center of gravity is not limited to standard vs. telephoto lenses; for example, the weight of interchangeable lenses can also cause a similar shift in the center of gravity.

[0133] Therefore, in the case of a telephoto lens (a relatively heavy interchangeable lens), the judgment method in (1) above is implemented to make the judgment stricter. Similarly, when a telephoto lens (a relatively heavy interchangeable lens) is attached, the judgment method in (5) above is given priority in the judgment of step S803. Furthermore, when the type of interchangeable lens is a telephoto lens (a relatively heavy interchangeable lens), the threshold in the judgment methods in (1) and (5) above may be made even narrower.

[0134] As mentioned above, by changing the determination method and threshold depending on the type of interchangeable lens attached, it becomes possible to switch to the excitation state more quickly when a telephoto lens (a relatively heavy interchangeable lens) is attached, thereby reducing the effects of shaking during earthquakes and other events.

[0135] In the embodiments 1 to 3 described above, an example was explained in which the current value applied to the stepping motor is controlled using two values ​​(values ​​to realize the de-excited state and the excited state, respectively). However, the current value required to excite the stepping motor in the standby state may be reduced by controlling the current value for the excited state using three or more values.

[0136] Furthermore, in that case, the current value used to energize the device may be changed depending on the magnitude of the shaking of the imaging device 100 (the value of the amount of shaking obtained from the first shaking detection unit 109 or the second shaking detection unit 701), the type of interchangeable lens, and whether or not an interchangeable lens is used.

[0137] For example, if the magnitude of the shaking is small, it becomes possible to reduce the current value required to maintain the position of the camera head 204. Also, if no interchangeable lens is attached or if a relatively light interchangeable lens is used, the current value for excitation may be reduced compared to other cases.

[0138] Current values ​​corresponding to the magnitude of the shake and the presence and type of interchangeable lenses may be stored in a table format in a memory unit (not shown) provided in the imaging device 100. The parameter processing unit 106 may refer to this table and determine the current value for exciting the motor in multiple stages.

[0139] As described above, by controlling the current value with three or more values, it is possible to excite the motor with the minimum necessary current value according to the load, making it possible to construct a more power-efficient system.

[0140] Although the above description describes an imaging device having both a pan motor and a tilt motor, the above embodiment is also applicable to imaging devices having only one of the two motors.

[0141] Although the present invention has been described in detail above based on its preferred embodiments, the present invention is not limited to the above embodiments, and various modifications and combinations of the above embodiments are possible in accordance with the spirit of the present invention, and these are not excluded from the scope of the present invention. Furthermore, some of the above embodiments may be combined as appropriate.

[0142] Furthermore, the present invention includes, for example, a system that realizes the functions of the above embodiment using at least one processor such as a CPU, memory, and circuitry (e.g., an ASIC). Alternatively, multiple processors may be used for distributed processing.

[0143] Furthermore, in order to implement some or all of the control in the above embodiment, a computer program that implements the functions of the above embodiment may be supplied to the imaging device, etc., via a network or various storage media.

[0144] The computer (or CPU or MPU, etc.) in the imaging device may read and execute the program. In that case, the program and the storage medium storing the program constitute the present invention. The present invention includes the following combinations.

[0145] (Configuration 1) An imaging device comprising: a camera head; a motor for changing the direction of the camera head; a first vibration detection means for detecting vibration of the camera head; and an excitation control means for changing the motor from the de-excited state to the excited state when the vibration detected by the first vibration detection means is determined to be greater than a predetermined value while the motor is in a de-excited state.

[0146] (Configuration 2) The imaging apparatus according to Configuration 1, characterized in that the excitation control means changes the motor from the excited state to the excited state, and if it is determined that the shaking is below a predetermined value, it changes the motor from the excited state to the de-excited state.

[0147] (Configuration 3) The imaging apparatus according to Configuration 2, characterized in that the excitation control means determines that the shaking is less than or equal to a predetermined value when the coordinate displacement of the camera head does not exceed a predetermined threshold for a predetermined time or longer.

[0148] (Configuration 4) The imaging apparatus according to Configuration 2 or 3, characterized in that the excitation control means determines that the shaking is below a predetermined value when the frequency of the coordinate displacement of the camera head falls below a predetermined threshold.

[0149] (Configuration 5) The imaging device according to any one of Configurations 1 to 4, characterized in that the excitation control means determines the magnitude of the shaking based on the angular displacement of the camera head.

[0150] (Configuration 6) The imaging apparatus according to Configuration 5, characterized in that the excitation control means determines the magnitude of the shaking based on whether the number of times the angular displacement of the camera head exceeds a predetermined threshold is equal to or greater than a predetermined threshold.

[0151] (Configuration 7) The imaging apparatus according to any one of Configurations 1 to 6, characterized in that the motor includes a pan motor or a tilt motor.

[0152] (Configuration 8) The imaging device according to any one of Configurations 1 to 7, wherein the motor includes a pan motor and a tilt motor, and the excitation control means determines whether the shaking in the pan direction and tilt direction of the camera head is greater than a predetermined value.

[0153] (Configuration 9) An imaging device according to any one of Configurations 1 to 8, further comprising a bottom case that holds the camera head in a rotatable state, wherein the bottom case is provided with a second vibration detection means for detecting vibration of the bottom case, and the excitation control means, in the de-excited state of the motor, determines, based on the outputs of the first vibration detection means and the second vibration detection means, that the vibration of the camera head and the bottom case is greater than a predetermined value, respectively, and changes the motor from the de-excited state to the excited state.

[0154] (Configuration 10) The imaging apparatus according to Configuration 9, wherein the excitation control means, after changing the motor from the de-excited state to the excited state, determines that the shaking of the camera head and the bottom case is below a predetermined value, and then changes the motor from the excited state to the de-excited state.

[0155] (Configuration 11) The imaging apparatus according to Configuration 10, characterized in that the excitation control means determines that the shaking of the bottom case is less than or equal to the predetermined value when the number of times the coordinate displacement of the bottom case exceeds a predetermined threshold is less than or equal to the predetermined threshold within a predetermined time.

[0156] (Configuration 12) An imaging device according to any one of Configurations 1 to 11, characterized in that when an interchangeable lens is attached, the determination conditions for changing from the non-excited state to the excited state are changed according to the type of interchangeable lens.

[0157] (Method) An imaging method using an imaging device having a camera head and a motor for changing the direction of the camera head, the imaging method comprising: a first shake detection step for detecting shake of the camera head; and an excitation control step for changing the motor from the de-excited state to an excited state if the shake of the camera head is determined to be greater than a predetermined value by the first shake detection step while the motor is in a de-excited state.

[0158] (Program) A computer program for controlling each means of the imaging device described in any one of configurations 1 to 12 by computer. [Explanation of Symbols]

[0159] 100: Imaging device 101: Imaging Unit 102: Pan drive unit 103: Tilt drive unit 104: Image Processing Unit 105: Pan-Tilt Control Unit 106: Parameter Processing Unit 107: System Control Unit 108: Communications Department 109: First vibration detection unit 150: Network

Claims

1. Camera head and, A motor for changing the direction of the camera head, A first shake detection means for detecting the shaking of the camera head, When the motor is in a de-excited state, the first vibration detection means determines that the vibration detected is greater than a predetermined value, and the excitation control means changes the motor from the de-excited state to an excited state. An imaging device characterized by having the following features.

2. The imaging apparatus according to claim 1, characterized in that the excitation control means changes the motor from the excited state to the de-excited state if it is determined that the shaking is below a predetermined value after changing the motor from the de-excited state to the excited state.

3. The imaging apparatus according to claim 2, characterized in that the excitation control means determines that the shaking is less than or equal to a predetermined value when the coordinate displacement of the camera head does not exceed a predetermined threshold for a predetermined period of time or longer.

4. The imaging apparatus according to claim 2, characterized in that the excitation control means determines that the shaking is below a predetermined value when the frequency of the coordinate displacement of the camera head falls below a predetermined threshold.

5. The imaging apparatus according to claim 1, characterized in that the excitation control means determines the magnitude of the shaking based on the angular displacement of the camera head.

6. The imaging apparatus according to claim 5, characterized in that the excitation control means determines the magnitude of the shaking based on whether the number of times the angular displacement of the camera head exceeds a predetermined threshold is equal to or greater than a predetermined threshold.

7. The imaging apparatus according to claim 1, characterized in that the motor includes a pan motor or a tilt motor.

8. The motor includes a pan motor and a tilt motor. The imaging apparatus according to claim 1, characterized in that the excitation control means determines whether the shaking in the pan direction and tilt direction of the camera head is greater than a predetermined value.

9. The system further includes a bottom case that holds the camera head in a rotatable state, The bottom case is equipped with a second vibration detection means for detecting vibrations of the bottom case, The excitation control means, in the de-excited state of the motor, If, based on the outputs of the first vibration detection means and the second vibration detection means, it is determined that the vibration of the camera head and the bottom case is greater than a predetermined value, The imaging apparatus according to claim 1, characterized in that the motor is changed from the de-excited state to the excited state.

10. The imaging apparatus according to claim 9, characterized in that the excitation control means, after changing the motor from the de-excited state to the excited state, determines that the shaking of the camera head and the bottom case are each below a predetermined value, and then changes the motor from the excited state to the de-excited state.

11. The imaging apparatus according to claim 10, characterized in that the excitation control means determines that the shaking of the bottom case is less than or equal to the predetermined value when the number of times the coordinate displacement of the bottom case exceeds a predetermined threshold within a predetermined time is less than or equal to the predetermined threshold.

12. The imaging device according to claim 1, characterized in that, when an interchangeable lens is attached, the determination conditions for changing from the de-energized state to the energized state are changed according to the type of interchangeable lens.

13. Camera head and, An imaging method using an imaging device having a motor for changing the direction of the camera head, A first shake detection step for detecting the shaking of the camera head, If, in the de-excited state of the motor, the first vibration detection step determines that the vibration of the camera head is greater than a predetermined value, an excitation control step is performed to change the motor from the de-excited state to the excited state, An imaging method characterized by having the following features.

14. A computer program for controlling each means of an imaging apparatus according to any one of claims 1 to 12 by computer.

Images