JP2018180341A - Imaging apparatus, driving mechanism for imaging apparatus, and control method for them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve excellent vibration-proofing with a simple configuration, in an imaging apparatus having a driving mechanism for changing the direction of the imaging apparatus and a control method for the imaging apparatus.SOLUTION: The imaging apparatus has the driving mechanism for changing the direction. The imaging apparatus generates a driving signal on the basis of the prescribed ratio of the first driving amount of the driving mechanism for suppressing an image blur caused by the shake of the imaging apparatus and the second driving amount of the driving mechanism for tracking a subject and makes the prescribed ratio when the moving speed of the driving mechanism or the frequency of the shake of the imaging apparatus satisfies a predetermined condition smaller than that when the moving speed of the driving mechanism or the frequency of the shake of the imaging apparatus does not satisfy the condition.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging device, a drive mechanism of the imaging device, and a control method thereof.

  Conventionally, an image pickup apparatus (pan-tilt camera) having a motorized pan-tilt mechanism is relatively large and generally used at a fixed position, and thus does not have an image shake correction function. However, due to the miniaturization of pan-tilt cameras, image blur correction becomes necessary when the use without fixing is increased, such as being attached to a vehicle or a human body (clothing) or used on a hand. .

  2. Description of the Related Art Conventionally, as an image blur correction method for an imaging device, a method using an external vibration isolation device such as a gimbal device, and a method for optically or electronically performing vibration isolation inside an imaging device are known. ).

JP, 2011-138028, A

  However, both methods are expensive because they require a dedicated configuration for vibration control. In addition, when the gimbal device is used, the size and weight of the imaging system increase, which reduces the usability. In addition, the anti-vibration mechanism inside the imaging apparatus may not be able to cope with large shakes.

  The present invention has been made in view of the problems of the related art as described above, and provides an image pickup apparatus having a drive mechanism for changing the direction of the image pickup apparatus and a control method thereof to realize excellent image stabilization with a simple configuration. As one purpose.

  The above-described objects are: a drive mechanism that changes the direction of the imaging device; a first calculation unit that calculates a first drive amount of the drive mechanism that suppresses image blurring due to a shake of the imaging device; And second control means for calculating a second drive amount of the drive mechanism, and control means for generating a drive signal for the drive mechanism, the control means comprising: a second drive means for generating a drive signal for the drive mechanism; The drive signal is generated based on the drive amount of the drive mechanism, and when the moving speed of the drive mechanism or the shake frequency of the imaging device satisfies a predetermined condition, the predetermined ratio is made smaller than that when the condition is not satisfied. This is achieved by an imaging device characterized in that.

  According to the present invention, in the imaging apparatus having a drive mechanism for changing the direction of the imaging apparatus and the control method thereof, it is possible to realize good vibration isolation with a simple configuration.

A block diagram schematically showing an example of a functional configuration of an imaging device according to an embodiment of the present invention (A) shows the phenomenon that the drive position oscillates, (b) schematically shows the effect of the embodiment A block diagram schematically showing an example of functional configurations of the pan / tilt control unit and the camera controller of FIG. 1 Diagram showing the relationship between the position on the image of the tracking target subject and the target position Diagram for explaining ratio control according to the embodiment Flowchart on ratio control according to the embodiment Diagram of ratio control according to the embodiment and its modification Flowchart on ratio control according to a modification of the embodiment Diagram of an example of ratio control based on swing signal A block diagram schematically showing an example of functional configurations of an imaging device and a pan and tilt mechanism according to another embodiment

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following, as a drive mechanism for changing the direction (direction of the optical axis) of the imaging apparatus according to the present invention, both a pan (horizontal direction (left and right) swing) mechanism and a tilt (vertical direction (upper and lower) swing) mechanism An embodiment applied to an imaging apparatus provided with However, the present invention is applicable to an imaging device having at least one of a pan mechanism and a tilt mechanism.

  FIG. 1 shows the configuration of an imaging device 100 according to an embodiment of the present invention. The imaging apparatus 100 has a subject tracking function, and adjusts the shooting direction by pan and / or tilt drive so that the subject specified by the external device 200 via the communication unit 117 is shot with a certain size and location. Adjust the angle of view with the zoom mechanism. The imaging apparatus 100 also realizes image blur correction (vibration reduction) by pan and / or tilt drive.

  There is no particular limitation on the method by which the external device 200 designates the subject or subject area to be tracked. For example, it is assumed that the captured image is sequentially transmitted to the external device 200 through the communication unit 117 and displayed on the touch display of the external device 200. In this case, it is possible to specify a subject region to be tracked or specify a subject (for example, a human face) by a touch operation on the touch display. It is assumed that the external device 200 supplies information on the position of the subject and the position and size of the area as information for specifying the subject or the subject area to be tracked. When the position information of the tracking target object is received, the camera controller 116 specifies the tracking target object region based on the position information.

The imaging apparatus 100 includes an imaging unit 101, a pan mechanism of the imaging unit 101, and a pan head unit 102 that is a tilt mechanism.
The lens unit 103 constitutes a photographing optical system, and has a variable power lens, a focus lens, a stop, etc. which can move in the optical axis direction. The lens unit 103 forms an object image on the imaging surface of the imaging element 104. The image sensor 104 is a CCD or CMOS image sensor in which a plurality of pixels are two-dimensionally arranged, and converts an object image into an analog image signal composed of an analog electric signal group obtained by the photoelectric conversion unit of each pixel. The imaging processing unit 105 applies processing such as noise reduction, AD conversion, white balance adjustment, and color interpolation to an analog image signal output from the imaging element 104 to generate image data. The image data is supplied to the camera controller 116. Note that, at the time of moving image shooting, the shooting unit 101 performs shooting and image data generation at a predetermined frame rate, and supplies the image data of each frame to the camera controller 116.

  In the pan head unit 102, the pan drive motor 106 is an actuator for turning the photographing unit 101 in the horizontal (left and right) direction. Here, the “horizontal direction” is the turning direction when the turning axis (pan axis) is in the vertical direction. The pan drive motor 106 operates based on a drive signal output from the pan drive circuit 107 under the control of the pan / tilt control unit 114. The pan position detection unit 108 detects the current pan position (the component in the optical axis direction in the plane orthogonal to the pan axis) of the current imaging unit 101 based on the position change (rotation amount) of the pan axis 118 detected as an electrical signal. Do. The pan speed detection unit 109 calculates the pan speed from the change per unit time of the pan position detected by the pan position detection unit 108.

  The tilt drive motor 110 is an actuator for pivoting the imaging unit 101 in the vertical (up and down) direction. Here, the “vertical direction” is the turning direction when the turning axis (tilt axis) is in the horizontal direction. The tilt drive motor 110 operates based on a drive signal output from the tilt drive circuit 111 based on the control of the pan / tilt control unit 114. The tilt position detection unit 112 detects the current tilt position of the imaging unit 101 (optical axis direction component in the plane orthogonal to the tilt axis) based on the position change (rotation amount) of the tilt axis 119 detected as an electric signal. Do. The tilt speed detection unit 113 calculates the tilt speed from the change per unit time of the tilt position detected by the tilt position detection unit 112.

  The pan and tilt control unit 114 sets the pan and / or tilt drive amount (second drive amount) for subject tracking so that the set subject is photographed at a predetermined position of the image according to the instruction from the camera controller 116. calculate. Further, the pan and tilt control unit 114 detects a shake amount of the imaging apparatus 100 from a shake signal output from an angular velocity sensor 115 which is, for example, a gyro sensor, and pan and / or tilt drive amount (first Calculate the drive amount or the anti-vibration drive amount). Then, the pan / tilt control unit 114 determines a pan and / or tilt target position based on the pan and / or tilt drive amount for tracking the subject and the pan and / or tilt drive amount for image stabilization, A drive signal for driving to a target position is generated. The pan and tilt control unit 114 supplies a drive signal to the pan drive circuit 107 and the tilt drive circuit 111.

  The pan and tilt control unit 114 includes, for example, one or more programmable processors such as a CPU, a ROM, and a RAM. The pan-tilt control unit 114 develops the program executable by the programmable processor stored in the ROM in the RAM and executes the program by the programmable processor to realize the above-described function. The pan and tilt control unit 114 may be realized by hardware such as an FPGA, an ASIC, or an ASSP.

  The camera controller 116 includes one or more programmable processors such as, for example, a CPU, a ROM, and a RAM. The camera controller 116 develops a program that can be executed by a programmable processor stored in the ROM in the RAM and executes the program by the programmable processor, thereby controlling each part of the imaging device 100 to realize various functions of the imaging device 100. The ROM also stores setting values and GUI data.

  In the imaging device 100, a target position of the area of the specific subject in the captured image is indicated from the external device 200 that can be communicated by the communication unit 117. The target position is a position where the area of the specific subject should exist in the captured image. The camera controller 116 performs the subject tracking function by determining the pan and / or tilt target position based on the difference between the target position of the subject area and the actual position so that the subject area continues to maintain the target position. To realize. The camera controller 116 can also control the angle of view (zoom magnification) of the lens unit.

  The communication unit 117 is a communication interface that enables communication between the imaging apparatus 100 and the external device 200, and supports wired and / or wireless communication. The communication unit 117 receives, from the external device 200, information for specifying a subject or a subject area, and information on a target position of the specified subject or the subject area, and supplies the information to the camera controller 116.

  FIG. 3 is a block diagram schematically showing functions realized by the pan and tilt control unit 114 and the camera controller 116. As shown in FIG. The first drive amount calculation unit 1161 calculates a drive amount of pan and / or tilt that eliminates the difference based on the difference between the target position of the subject supplied from the communication unit 117 and the actual position.

FIG. 4 shows an example of a captured image. The captured image 401 includes the face area 402 of a person. Here, the face area 402 is designated as the subject area, and the center coordinates O (x0, y0) 404 of the image are designated from the external device 200 as the target position. It shall be. For example, when the barycentric coordinates of the subject area are used as the position of the subject area, the first drive amount calculation unit 1161 determines the difference between the target position O (x0, y0) and the actual position H (x1, y1). The drive amount is determined by multiplying each conversion coefficient of pan or tilt. Pan drive amount Dp and tilt when the x-axis of the image coordinates is perpendicular to the pan axis and the optical axis, y axis is parallel to the pan axis, pan conversion coefficient is kp, and tilt conversion coefficient is kt The driving amount Dt of is expressed by the following equations (1) and (2).
Dp = (x1-x0) x kp (1)
Dt = (y1-y0) x kt (2)

  Here, the conversion coefficients kp and kt in Equations (1) and (2) are coefficients for converting the difference between image coordinates into pan and tilt driving amounts. The conversion coefficients kp and kt are determined according to the size of the image sensor 104, the focal length of the lens unit 103, and the detection resolution of the pan position detection unit 108 and the tilt position detection unit 112.

  Note that the first drive amount calculation unit 1161 may be positioned within the allowable frame 403 even if the actual position H (x1, y1) of the designated subject area is different from the target position O (x0, y0). For example, it is considered to be at the target position. In this case, the first drive amount calculation unit 1161 does not calculate the pan and tilt drive amounts for moving the subject region, or calculates the pan and tilt drive amounts for which the pan and tilt drive are not substantially performed. This is to suppress hunting in which pan and tilt driving is repeatedly performed across the target position. The pan and tilt drive amounts Dp and Dt calculated by the camera controller 116 (first drive amount calculation unit 1161) are supplied to the pan and tilt control unit 114.

  The pan / tilt control unit 114 causes the pan and / or tilt drive amount notified from the camera controller 116 to reflect a predetermined ratio of the pan and / or tilt drive amount for performing the image shake correction, and performs final pan and / or tilt. Or calculate the tilt drive amount.

  The shake correction amount calculation unit 1141 converts a pan and / or tilt correction amount (anti-vibration driving amount) for canceling the shake indicated by the shake signal based on the shake signal output from the angular velocity sensor 115. The drive amount calculation unit 1142 takes into consideration the shake of the imaging device 100 based on the pan and / or tilt drive amount supplied from the camera controller 116 and the anti-vibration drive amount supplied from the shake correction amount calculation unit 1141. Determine the pan and / or tilt drive amount.

  The drive amount calculation unit 1142 selectively uses the anti-vibration drive amount in determining the pan and / or tilt drive amount. Specifically, the drive amount calculation unit 1142 determines whether to use the image stabilization correction amount according to the comparison result of the comparison unit 1145 and the count value of the timer 1146.

  The acceleration detection unit 1143 detects the drive speeds of pan and tilt supplied from the pan speed detection unit 109 and the tilt speed detection unit 113 as accelerations. The comparison unit 1145 compares the acceleration detected by the acceleration detection unit 1143 with the threshold stored in the image stabilization OFF threshold holding unit 1144, and supplies the comparison result to the drive amount calculation unit 1142.

  Here, the threshold will be described. By realizing the image shake correction function by the pan and / or tilt operation, it is not necessary to provide a mechanism dedicated to the image shake correction, and problems such as an increase in the size and cost of the apparatus can be significantly reduced. On the other hand, there is a problem that shake of the imaging device 100 occurs due to pan and / or tilt drive.

  FIG. 2A shows the change in the actual position and the target position of pan when the pan drive is started for tracking the subject at time ta while performing the image blur correction by the pan drive. The target position A is the target position of the pan (for image stabilization) before driving at ta, and the target position B is the target position of the pan driving started at ta.

  When pan drive from position A to position B is started, the target position (pan drive + anti-vibration target position) considering the pan drive amount for anti-vibration purpose vibrates back and forth centering on position B and amplitudes with time Is larger (oscillation). This is because the vibration generated by the vibration isolation drive is larger than the vibration canceled by the vibration isolation drive. In order to avoid the occurrence of such an oscillation phenomenon, the minimum value of the acceleration at which the oscillation phenomenon occurs from the stopped state is measured in advance by experiments and stored in the anti-vibration OFF threshold value storage unit 1144 as a threshold value.

  If it is determined that the acceleration detected by the acceleration detection unit 1143 is equal to or higher than the threshold as a result of the comparison by the comparison unit 1145, the timer 1146 starts operation. Further, the second drive amount calculation unit 1142 changes the ratio of the pan correction amount (anti-vibration drive amount) to be reflected (for example, added) to the pan drive amount supplied from the camera controller 116. The timer 1146 may actually be a counter whose value represents time.

  Specifically, in the present embodiment, when it is determined that the acceleration detected by the acceleration detection unit 1143 is equal to or higher than the threshold, the second drive amount calculation unit 1142 does not add the pan correction amount, and supplies from the camera controller 116 The amount of panning drive to be performed is determined as the final amount of panning drive.

  When the value of the timer 1146 reaches a predetermined value, the second drive amount calculator 1142 further determines the final pan drive amount by further using the pan correction amount. When the value of the timer 1146 reaches a predetermined value, the second drive amount calculation unit 1142 stops the operation of the timer 1146 and clears the value to zero.

  Although only pan drive has been described here for ease of explanation and understanding, the same operation can be performed for tilt drive. As described above, when it is determined that the acceleration detected by the acceleration detection unit 1143 (that is, the magnitude of the shake of the imaging device 100) is equal to or greater than the threshold, the second drive amount calculation unit 1142 continues until a predetermined time elapses. The final pan and / or tilt drive amount is determined without using the antivibration drive amount. Then, after a predetermined time has elapsed, the final pan and / or tilt drive amount is determined using the vibration isolation drive amount until it is next determined that the acceleration detected by the acceleration detection unit 1143 is equal to or higher than the threshold.

  FIGS. 5A to 5C respectively show the pan drive speed and the acceleration detected by the acceleration detection unit 1143 when pan drive for image stabilization and object tracking is performed from the state where the pan drive is stopped. The example of the time change of the absolute value is shown.

  Δtc in FIG. 5 is a period during which the ratio of the pan correction amount (anti-vibration driving amount) to be added when determining the final pan driving amount is changed. In the period Δtc, the vibration reduction OFF, that is, the vibration reduction drive amount is set to zero. Therefore, the addition ratio of the pan correction amount is 0% in the period Δtc.

  As shown in FIG. 5B, a positive threshold A and a negative threshold B are set for the pan drive acceleration, and the pan drive acceleration detected by the acceleration detection unit 1143 exceeds the threshold A and is less than the threshold B In the case of, anti-vibration is OFF. That is, when the pan drive positive or negative acceleration exceeds the threshold value, the vibration isolation is turned off. The absolute values of the threshold A and the threshold B may be equal or different. Here, it is assumed that the absolute values of the threshold A and the threshold B are equal, and the thresholds A and B are collectively shown as the threshold C in FIG.

  Here, there is shown an example of pan driving in which acceleration is performed from time t0 to t1 and then the speed is substantially constant until time t2 and then deceleration is performed until time t3. Since the acceleration from time t0 to time t1 does not exceed the threshold A, the image stabilization is ON, and the pan correction amount (vibration isolation drive amount) is reflected in the pan drive amount. On the other hand, at the time of deceleration from time t2 to time t3, the acceleration (deceleration) becomes smaller than the threshold value B, so that the image stabilization is turned off. However, in order to suppress the occurrence of hunting or a malfunction due to noise, in the example of FIG. 5, the vibration reduction is not turned off immediately after (or just after time t2) below threshold B (or above threshold A). Instead, at the time when the acceleration continues below the threshold B (or exceeds the threshold A) continuously for a predetermined time (time t3), the anti-vibration is OFF. As shown in FIG. 5C, similar control may be performed by setting a threshold for the absolute value of the acceleration. Although FIG. 5 shows control for pan drive, tilt drive can be similarly controlled.

  Returning to FIG. 3, the compensator 1147 determines the actual pan and / or tilt position detected by the pan position detector 108 and / or the tilt position detector 112 and the pan and / or tilt calculated by the drive amount calculator 1142. The target position of the drive is calculated from the drive amount. Then, the compensator 1147 generates a pan and / or tilt drive signal by, for example, PID control calculation so that the pan and / or tilt position becomes the target position.

  Next, the ratio control operation of the image stabilization drive amount in the pan and tilt control unit 114 will be described using the flowchart of FIG. This operation is performed when the imaging apparatus 100 is powered on.

  In step S602, the pan / tilt control unit 114 enables pan and / or tilt driving for image stabilization (vibration isolation ON), and stores, for example, data representing the image stabilization ON in the internal memory. For example, the pan and tilt control unit 114 can use a 1-bit flag indicating whether the image stabilization is ON or OFF.

  For example, the pan-tilt control unit 114 determines whether or not the image stabilization is ON with reference to the flag in S603, and advances the processing to S604 if it is determined to be the image stabilization ON or to S605 if it is not determined to be the image stabilization ON. .

In S604, the pan / tilt control unit 114 (shake correction amount calculation unit 1141) calculates the anti-vibration drive amount (pan and / or tilt correction amount), and advances the process to S609.
On the other hand, in S605, the pan and tilt control unit 114 (second drive amount calculation unit 1142) determines whether the count value of the timer 1146 is equal to or more than a predetermined value. If not determined, the process proceeds to S606.

In step S606, the pan / tilt control unit 114 (second drive amount calculation unit 1142) sets the ratio of the anti-vibration drive amount (pan and / or tilt correction amount) to 0 and sets the process to S609. Advance.
In S607 and S608, the pan and tilt control unit 114 (second drive amount calculation unit 1142) stops the operation of the timer 1146, clears the count value to 0, and returns the process to S602.

  The pan and tilt control unit 114 (second drive amount calculation unit 1142) in step S609 pans and pans based on the anti-vibration drive amount calculated in step S604 and the pan and / or tilt drive amount supplied from the camera controller 116. And / or determine the target position of the tilt drive.

At S610, the pan / tilt control unit 114 (compensator 1147) calculates a pan and / or tilt drive signal from the target position.
In S611, the pan / tilt control unit 114 (compensator 1147) supplies the drive signal calculated in S610 to the pan drive circuit 107 and / or the tilt drive circuit 111. Thereby, pan and / or tilt drive corresponding to the drive signal is started.

  In step S612, the pan / tilt control unit 114 (second drive amount calculation unit 1142) causes the comparison unit 1145 to compare the pan and / or tilt acceleration detected by the acceleration detection unit 1143 with the threshold. It is determined whether it exceeds. Here, as shown in FIG. 5C, it is determined whether or not the absolute value of the acceleration exceeds the threshold, but a threshold different depending on the degree of deceleration may be used. In this case, the pan and tilt control unit 114 determines whether the deceleration is less than the threshold.

If it is determined that the acceleration exceeds the threshold value, the pan and tilt control unit 114 (second drive amount calculation unit 1142) proceeds to S613. If it is determined that the acceleration does not exceed the threshold, the process proceeds to S603. return.
The pan / tilt control unit 114 (second drive amount calculation unit 1142) turns off the anti-vibration setting in S613, starts the operation of the timer 1146 in S614, and returns the process to S603.

  FIG. 2B shows an example of the time change of the target position and the actual position of the pan and tilt mechanism when the image stabilization is controlled to be turned off for a predetermined period when the pan acceleration exceeds the threshold value. Times t3 and t4 in the example of FIG. 2 (b) correspond to times t3 and t4 in FIG. As described above, in the example of FIG. 5, the vibration reduction is set to OFF during a period from time t3 at which the acceleration (deceleration) continues to exceed the threshold for a predetermined time continuously (time t3) to time t4.

  As can be seen from the comparison with FIG. 2 (a), although the vibration at the pan position centering on the target position B is generated also by the control according to the present embodiment, it converges immediately and the oscillation phenomenon does not occur. . As described above, in the present embodiment, the image stabilization is turned OFF when the absolute value of the shake acceleration of the apparatus exceeds the threshold, and the image stabilization is turned ON when the threshold is not exceeded. As a result, it is possible to realize the anti-shake function using the pan-tilt mechanism while avoiding the oscillation phenomenon that the actual position of the pan-tilt mechanism does not converge to the target position due to the shake caused by the anti-vibration drive.

(Modification)
In addition, in order to facilitate the description and the understanding so far, when the absolute value of the shake acceleration of the device exceeds the threshold value, the vibration isolation is turned OFF and the ratio of the vibration isolation drive amount reflected in the pan and / or tilt drive amount is The configuration to be 0% has been described. However, the ratio of the anti-vibration drive amount to be reflected in the pan and / or tilt drive amount is not limited to the switching between 100% and 0%.

  FIG. 7 shows an example of ratio control of the anti-vibration drive amount to be reflected in the ratio change period Δtc (from time t3 to time t4). In FIG. 7A, the ratio of the anti-vibration control amount is changed from 100% to 0% when the acceleration continues for a predetermined time and exceeds the threshold, as described above with reference to the example of FIG. It shows control to make the ratio 0% to 100% after lapse of time.

  On the other hand, as shown in FIGS. 7 (b) and 7 (c), ratio control may be performed such that the ratio is temporally changed at the time of vibration isolation OFF. FIG. 7B shows an example of ratio control in which the ratio is reduced at a constant ratio after the acceleration exceeds the threshold and the reduction value of the ratio is a value larger than 0. 7C is the same as FIG. 7B in the control for reducing the ratio, but during the ratio change period Δtc, the ratio becomes 100% at the end of the ratio change period Δtc. The example of proportional control which increases a ratio at a fixed rate is shown.

  In addition, although the configuration in which the length of the ratio change period Δtc is set until the predetermined time elapses from when the ratio is changed (when the count value of the timer 1146 reaches the predetermined value) has been described, the length of the ratio change period Δtc May be determined dynamically. For example, the ratio change period Δtc may be continued until the magnitude of the shake of the imaging apparatus 100 (the amplitude of the shake signal output by the angular velocity sensor 115) becomes equal to or less than a predetermined value.

  The ratio control operation of the image stabilization drive amount in the pan and tilt control unit 114 in the case of changing the length of the ratio change period Δtc in accordance with the magnitude of the shake of the imaging device will be described using the flowchart of FIG. In FIG. 8, the same steps as in FIG. 6 carry the same reference numerals, and the explanation thereof is omitted. The ratio control according to the present modification is to remove S607 and S608 from the ratio control shown in the flowchart of FIG. 6 and execute S801 instead of S605.

  If it is determined in step S603 that the image stabilization is not ON, the pan and tilt control unit 114 advances the process to step S801. In S801, the pan / tilt control unit 114 (second drive amount calculation unit 1142) determines whether the magnitude (amplitude) of the output signal (shake signal) of the angular velocity sensor 115 is equal to or less than a predetermined value. Then, if the pan-tilt control unit 114 (second drive amount calculation unit 1142) determines that the amplitude of the shake signal is less than or equal to the predetermined value, the process returns to S602 and the vibration reduction is returned to ON. For example, the process advances to step S606 to continue the vibration reduction OFF. When the vibration reduction ON is to be returned, the ratio of the vibration reduction drive amount may be gradually returned.

  FIG. 9A shows an example of the temporal change of the output signal (shake signal) of the angular velocity sensor 115 after the start of the ratio change period and the end determination of the ratio change period. Here, an example is shown in which the ratio change period ends (returns to anti-vibration ON) when the amplitude of the output signal of the angular velocity sensor 115 continues for a predetermined time and becomes less than the threshold.

  As another control method, for example, the output signal of the angular velocity sensor 115 is subjected to fast Fourier transform (FFT), and when the magnitude of a specific frequency component becomes equal to or less than a predetermined value, the ratio change period is ended and the vibration reduction is returned to ON. You may do so. FIG. 9B shows an example in which the output signal of the angular velocity sensor 115 is subjected to FFT. Here, the frequency component with the largest amplitude is the natural frequency of the imaging device 100.

  When the vibration isolation is turned on when the natural frequency of the imaging device 100 and the amplitude of the frequency component in the vicinity thereof are large, the possibility of the occurrence of the oscillation phenomenon becomes high. Therefore, when it is determined that the natural frequency and the amplitude of the frequency component in the vicinity thereof are less than the threshold value D, the ratio change period can be ended and the vibration reduction can be returned to ON.

  In addition, the ratio of the anti-vibration drive amount in the ratio change period may be made different according to the main frequency of the shake of the imaging device (for example, the frequency with the largest amplitude). For example, as shown in FIG. 9C, when the main frequency of the shake of the imaging device is included in the natural frequency of the imaging device and the range in the vicinity thereof, the ratio of the vibration isolation drive amount is You may lower it. Further, when the main frequency of the shake of the imaging device is not included in the natural frequency of the imaging device and the range in the vicinity thereof, the ratio of the anti-vibration driving amount may be returned to the original. As described above, the ratio of the anti-vibration drive amount may be changed according to the shake frequency of the imaging device, not the time change (acceleration) of the pan or tilt speed.

  As described above, according to the present embodiment, the drive mechanism for changing the orientation of the imaging device, such as the pan-tilt mechanism, is used as a vibration reduction mechanism for reducing image blurring due to shake of the imaging device, There is no need to provide a dedicated member for vibration isolation. Further, when the moving speed of the drive mechanism and the shake frequency of the imaging device satisfy the predetermined conditions, the predetermined ratio reflecting the anti-vibration drive amount is made smaller than in the case other than that. Therefore, even if the drive mechanism is moving for tracking an object, for example, the drive mechanism can be quickly moved to the target position.

(Other embodiments)
Although the above-described embodiment has described the configuration in which the imaging device includes the pan and tilt mechanism, the present invention can also be implemented in a pan and tilt mechanism (a pan head) separate from the imaging device. In this case, as shown in FIG. 10, the imaging device 101 ′ may be attached to the pan and tilt mechanism 102 ′. In this case, the camera controller 116 and the communication unit 117 are included in the imaging apparatus 101 ′, and the pan / tilt control unit 114 of the pan and tilt mechanism 102 ′ acquires the pan and / or tilt drive amount from the camera controller 116 included in the imaging apparatus 101 ′. When the imaging device 101 ′ has an angular velocity sensor, a shake signal may also be acquired from the camera controller 116.

  In the above embodiment, the configuration for receiving from the external device 200 the information for specifying the tracking target subject or the subject area has been described. However, the tracking target subject or the tracking target subject using the display unit or the operation unit of the imaging apparatus itself The subject area may be specified.

  The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or storage medium, and one or more processors in a computer of the system or apparatus read and execute the program. Can also be realized. It can also be implemented by a circuit (eg, an ASIC) that implements one or more functions.

114 pan tilt controller 115 angular velocity sensor 116 camera controller 1141 shake correction amount calculator 1142 second drive amount calculator 1143 acceleration detector 1145 comparator 1161 first Drive amount calculation unit.

Claims (16)

A drive mechanism that changes the orientation of the imaging device;
First calculation means for calculating a first drive amount of the drive mechanism for suppressing an image blur due to a shake of the imaging device;
Second calculation means for calculating a second drive amount of the drive mechanism for tracking an object;
Control means for generating a drive signal of the drive mechanism;
The control means generates the drive signal based on a predetermined ratio of the first drive amount and the second drive amount, and the moving speed of the drive mechanism or the frequency of the shake of the imaging device is predetermined. When the above condition is satisfied, the predetermined ratio is made smaller than when the condition is not satisfied,
An imaging device characterized by   The imaging device according to claim 1, wherein the control means generates the drive signal based on a drive amount obtained by adding the predetermined ratio of the first drive amount to the second drive amount. The control means makes the predetermined ratio smaller when the temporal change of the moving speed of the drive mechanism exceeds a threshold, than when the temporal change of the moving speed of the drive mechanism is equal to or less than the threshold.
The imaging device according to claim 1 or 2, wherein The control means
The driving signal is generated based on the second driving amount when the temporal change of the moving speed of the driving mechanism exceeds a threshold.
The driving signal is generated based on the first driving amount and the second driving amount when the time change of the moving speed of the driving mechanism is equal to or less than the threshold.
The imaging device according to claim 3, characterized in that:   The control means makes the predetermined ratio smaller than the case where the time change of the moving speed of the drive mechanism is less than or equal to the threshold when the time change of the moving speed of the drive mechanism continuously exceeds a threshold for a predetermined time. The imaging device according to claim 3 or 4, characterized in that:   The control means changes the predetermined ratio from the first ratio to the second ratio when the time change of the moving speed of the drive mechanism exceeds a threshold value. An imaging device according to claim 1.   7. The apparatus according to claim 6, wherein the control means changes the predetermined ratio from the first ratio to the second ratio over time when the temporal change in moving speed of the drive mechanism exceeds a threshold. The imaging device of description.   The imaging device according to any one of claims 1 to 7, wherein the control means returns the predetermined ratio to the original ratio when a predetermined time elapses after reducing the predetermined ratio. .   The control means returns the predetermined ratio to the original ratio when the magnitude of the shake of the imaging device becomes equal to or less than a predetermined value after reducing the predetermined ratio. The imaging device according to any one of the above. When the magnitude of the predetermined frequency component of the shake of the imaging device is equal to or greater than a threshold, the control means may perform the predetermined ratio more than when the magnitude of the predetermined frequency component is less than the threshold. To make
The imaging device according to claim 1,   11. The image pickup apparatus according to claim 10, wherein the predetermined frequency component is a frequency component in a range including the natural frequency of the image pickup apparatus.   The control means is characterized in that the predetermined ratio is returned to the original ratio when the shake frequency of the imaging device is not included in the predetermined frequency range after decreasing the predetermined ratio. The imaging device according to claim 10. A driving mechanism of an imaging device, which changes the direction of the imaging device,
First calculation means for calculating a first drive amount of the drive mechanism for suppressing an image blur due to a shake of the imaging device;
Second calculation means for calculating a second drive amount of the drive mechanism for tracking an object;
Control means for generating a drive signal of the drive mechanism;
The control means generates the drive signal based on a predetermined ratio of the first drive amount and the second drive amount, and the moving speed of the drive mechanism or the frequency of the shake of the imaging device is predetermined. When the above condition is satisfied, the predetermined ratio is made smaller than when the condition is not satisfied,
A drive mechanism of an imaging device characterized in that. It is a control method of an imaging device, and
A first calculation step of calculating a first driving amount for suppressing an image blur due to a shake of the imaging device, of a drive mechanism that changes the direction of the imaging device;
A second calculation step of calculating a second drive amount of the drive mechanism for tracking an object;
And d) generating a drive signal of the drive mechanism.
In the control step, the drive signal is generated based on a predetermined ratio of the first drive amount and the second drive amount, and the moving speed of the drive mechanism or the frequency of the shake of the imaging device is predetermined. When the above condition is satisfied, the predetermined ratio is made smaller than when the condition is not satisfied,
And controlling the imaging device. A control method of a drive mechanism of an imaging device, which changes the direction of the imaging device,
A first calculation step of calculating a first drive amount of the drive mechanism for suppressing an image blur due to a shake of the imaging device;
A second calculation step of calculating a second drive amount of the drive mechanism for tracking an object;
And d) generating a drive signal of the drive mechanism.
In the control step, the drive signal is generated based on a predetermined ratio of the first drive amount and the second drive amount, and the moving speed of the drive mechanism or the frequency of the shake of the imaging device is predetermined. When the above condition is satisfied, the predetermined ratio is made smaller than when the condition is not satisfied,
And controlling the drive mechanism of the imaging apparatus.   The program for functioning the said computer of the said imaging device which has a drive mechanism which changes direction of an imaging device, and a computer as each means of an imaging device of any one of Claims 1-12.

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