JP4298723B2 - Imaging apparatus, shake correction method, and program - Google Patents

Description

  The present invention relates to an imaging apparatus, a shake correction method, and a program, and in particular, an imaging apparatus having a shake correction function that corrects shake of a captured image by driving an optical shake correction lens that is optically movable. The present invention relates to a shake correction method applied to the imaging apparatus, and a program for causing a computer to execute the shake correction method.

  2. Description of the Related Art Conventionally, in an imaging apparatus having a shake correction function that detects shake of an imaging apparatus and drives an optically movable shift lens to correct shake of a captured image, an angular velocity sensor is often used for shake amount detection. . In this angular velocity sensor, a vibrating material such as a piezoelectric element is vibrated at a constant frequency, and the force due to the Coriolis force generated by the rotational motion component is converted into a voltage to obtain angular velocity information. The obtained angular velocity is integrated to calculate a shake amount, a correction position control signal is output based on the shake amount, and a shift lens is driven in a direction to cancel the image shake amount, thereby performing camera shake correction. .

  In this shift lens drive, the current position of the shift lens is detected as a shift lens position signal, and this is fed back and feedback control is performed to reflect it in the corrected position control signal. In general, feedback control uses a control method called PID control.

  The D compensation (differential compensation) is used to improve the decrease of the gain margin GM and the phase margin PM due to the overcompensation of the P compensation (proportional compensation) and improve the stability of the feedback control. I compensation (integral compensation) is used to improve the offset characteristics of feedback control. Feedback control in which these P compensation, I compensation, and D compensation are selected and combined as necessary is called PID control.

As a conventional imaging apparatus in which camera shake correction control is performed, for example, there is one disclosed in Patent Document 1. That is, when PID control is used for feedback control, high frequency components of noise are emphasized in the feedback loop by D compensation (differential compensation), and vibration noise is generated due to this. In the above-described conventional camera shake correction technology, the combination of PID control is changed before and after the start of exposure in order to reduce the vibration noise. Further, the presence / absence of use of the feedforward function is switched before and after the start of exposure.
JP-A-11-218795

  However, in the conventional imaging apparatus in which the above-described camera shake correction control is performed, when the PID control is used for the camera shake correction control, it is possible to accurately follow the command value, but the image stabilization effect is deteriorated. On the other hand, when PD control is used for camera shake correction control, a certain deviation (offset) occurs with respect to the command value, but there is a problem that the image stabilization effect is high.

  The present invention has been made in view of such problems, and provides an image pickup apparatus, a shake correction method, and a program that can realize an image stabilization capable of removing an offset and at the same time enhancing an image stabilization effect. The purpose is to do.

In order to achieve the above object, according to the first aspect of the present invention, a switch for starting an exposure operation and an optical shake correction lens capable of optically moving the position are driven to correct shake of a photographed image. An image pickup apparatus having a shake correction function , a detection unit that detects a degree of shake applied to the image pickup apparatus, and a target position of the optical shake correction lens according to the degree of shake detected by the detection unit Determining means for determining the position, detecting means for detecting the actual position of the optical shake correction lens, and feedback so that the actual position detected by the position detecting means converges to the target position determined by the determining means. a feedback control means for controlling, when said switch is off, the feedback control means, the running and derivative control with integral control and proportional control work the shake correction function 1 To execute the control method, when the switch is turned on from off, the before starting the exposure operation, the feedback control means, second to work the shake correction function by running a differentiation control and proportional control There is provided an imaging device comprising control means for controlling to execute the control method.

According to the invention of claim 6, further comprising a switch for starting the exposure operation, the shake correction function for correcting the shake of the captured image by driving the possible optical shake correction lens moving optically location A shake correction method applied to the image pickup apparatus, a detection step for detecting a shake degree applied to the image pickup apparatus, and a target of the optical shake correction lens according to the shake degree detected in the detection step A determination step for determining a position; a position detection step for detecting an actual position of the optical shake correction lens; and an actual position detected in the position detection step so as to converge to the target position determined in the determination step. a feedback control step of performing feedback control, the when the switch is off, in the feedback control step, proportional control and integral control and derivative control First control method to work the shake correction function and the execution is performed, when the switch is turned from off to on, before starting the exposure operation, in the feedback control step, proportional control and differential control And a control step for performing control so that the second control method for operating the shake correction function is executed.

  Furthermore, a program for causing a computer to execute the shake correction method is provided.

According to the present invention, there is provided an imaging device having a switch for starting an exposure operation and a shake correction function for correcting a shake of a photographed image by driving an optical shake correction lens that is optically movable. The degree of shake applied to the imaging device is detected, and the target position of the optical shake correction lens is determined according to the detected degree of shake. On the other hand, the actual position of the optical shake correction lens is detected, and feedback control is performed so that the detected actual position converges to the determined target position. When the switch is off, in the feedback control, the first control method for executing the shake correction function by executing proportional control, integral control, and differential control is executed. Further , when the switch is turned on from off, before starting the exposure operation , the feedback control performs the second control method for executing the shake correction function by executing the proportional control and the differential control. .

  As a result, the first control method with a small offset is executed even if the shake correction performance is slightly inferior during the period before the start of shooting when exposure adjustment and focus adjustment are performed, and the shake correction performance is excellent after the start of shooting. It is possible to execute the second control method.

  Further, in the second control method after the start of exposure, the integral compensation coefficient determined immediately before the start of exposure is held, and a command for driving the optical shake correction lens using the held integral compensation coefficient. Generate a signal.

  As a result, it is possible to perform shake correction control with little offset and excellent shake correction performance.

  It should be noted that in the stage before the start of exposure, there is no particular problem even if the shake correction performance is slightly inferior because it is not actually photographed (exposure) but only acquired as a monitor image.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[First Embodiment]
FIG. 1 is a block diagram showing the configuration of the imaging apparatus according to the first embodiment of the present invention. This imaging device is a digital camera mainly for taking still images.

  In FIG. 1, reference numeral 101 denotes a zoom unit, which includes a zoom lens that performs zooming. Reference numeral 102 denotes a zoom drive control unit that controls the drive of the zoom unit 101. Reference numeral 103 denotes a shift lens unit whose position can be changed with respect to the optical axis. Reference numeral 104 denotes a shift lens drive control unit, which drives and controls the shift lens unit 103. Reference numeral 105 denotes an aperture / shutter unit. Reference numeral 106 denotes an aperture / shutter drive control unit, which controls the drive of the aperture / shutter unit 105. A focus unit 107 includes a lens that performs focus adjustment. A focus drive control unit 108 controls the drive of the focus unit 107. Reference numeral 109 denotes an imaging unit that converts an optical image that has passed through each lens group into an electrical signal. Reference numeral 110 denotes an imaging signal processing unit that converts an electrical signal output from the imaging unit 109 into a video signal. A video signal processing unit 111 processes the video signal output from the imaging signal processing unit 110 according to the application. Reference numeral 112 denotes a display unit, which displays an image as necessary based on a signal output from the video signal processing unit 111. Reference numeral 113 denotes a power supply unit that supplies power to the entire system according to the application. An external input / output unit 114 inputs / outputs communication signals and video signals to / from the outside. Reference numeral 115 denotes an operation unit for operating the system. Reference numeral 116 denotes a storage unit that stores various data such as video information. Reference numeral 117 denotes a control unit that controls the entire system.

  Next, the operation of the imaging apparatus having such a configuration will be described.

  The operation unit 115 has a shutter release button configured such that the first switch and the second switch are sequentially turned on according to the amount of pressing. The first switch is turned on when the shutter release button is depressed approximately halfway, and the second switch is turned on when the shutter release button is depressed to the end. When the first switch of the operation unit 115 is turned on, the focus drive control unit 108 drives the focus unit 107 to perform focus adjustment, and the aperture / shutter drive control unit 106 drives the aperture / shutter 105 to set an appropriate value. Set to exposure. Further, when the second switch is turned on, the image data obtained from the light image exposed to the imaging unit 109 is stored in the storage unit 116.

  At this time, if there is an instruction to turn on the image stabilization from the operation unit 115, the control unit 117 instructs the shift lens drive control unit 104 to perform the image stabilization operation, and the shift lens drive control unit 104 that receives the instruction instructs the image stabilization off. Anti-vibration operation is performed until

  Further, in this imaging apparatus, one of the still image shooting mode and the moving image shooting mode can be selected from the operation unit 115, and the operating condition of each actuator can be changed in each mode.

  When an instruction for zooming magnification is given to the operation unit 115, the zoom drive control unit 102 that has received the instruction via the control unit 117 drives the zoom unit 101 to place the zoom lens at the designated zoom position. Moving. At the same time, based on the image information sent from the imaging unit 109 and processed by each signal processing unit (110, 111), the focus drive control unit 108 drives the focus unit 107 to perform focus adjustment.

  FIG. 2 is a block diagram showing an internal configuration of the shift lens drive control unit 104.

  Reference numeral 201 denotes a pitch direction gyro unit, which detects vibration in the vertical direction (pitch direction) of the imaging apparatus in a normal posture (an attitude in which the length direction of the image frame substantially matches the horizontal direction). Reference numeral 202 denotes a yaw direction gyro unit that detects vibrations in the horizontal direction (yaw direction) of an imaging apparatus in a normal posture. Reference numerals 203 and 204 denote anti-vibration control units in the pitch direction and yaw direction, respectively, which perform anti-vibration control and shift lens position control according to the situation. Reference numerals 205 and 206 respectively denote PID units, which obtain control amounts from corrected position control signals in the pitch direction and yaw direction and position signals indicating the position of the shift lens, and output position command signals. Reference numerals 207 and 208 respectively denote drive units that drive the shift lens unit 103 based on position command signals sent from the PID units 205 and 206. Reference numerals 209 and 210 denote Hall elements, which detect the positions of the shift lens unit 103 in the pitch direction and the yaw direction, respectively.

  Next, position control of the shift lens unit 103 by the shift lens drive control unit 104 will be described.

  In the position control of the shift lens unit 103, the shift is performed in each direction based on a shake information signal (angular velocity signal) representing the shake in the pitch direction and yaw direction of the imaging device from the pitch direction gyro unit 201 and the yaw direction gyro unit 202. The lens unit 103 is driven. A magnet is attached to the shift lens unit 103. The magnets are detected by the Hall elements 209 and 210, and position signals indicating the position of the shift lens are sent to the PID units 205 and 206, respectively. The PID units 205 and 206 perform feedback control such that these position signals converge on the corrected position control signals sent from the image stabilization control units 203 and 204, respectively. Since the position signals output from the Hall elements 209 and 210 have individual variations, the output of the Hall elements 209 and 210 is set so that the shift lens moves to a predetermined position with respect to a predetermined correction position control signal. Adjustments need to be made. At this time, the PID units 205 and 206 perform PID control using proportional control, integral control, and differential control.

  Based on shake information signals (angular velocity signals) from the pitch direction gyro 201 and the yaw direction gyro 202, the image stabilization controllers 203 and 204 move the position of the shift lens in a direction in which image shake due to shake of the imaging device is corrected. A correction position control signal is output. Thus, even if camera shake or the like occurs in the imaging apparatus, image blur can be prevented.

  FIG. 3 is a block diagram illustrating an internal configuration of the image stabilization control unit 203. Note that the image stabilization control unit 204 also has the same internal configuration as the image stabilization control unit 203, and the description of the image stabilization control unit 204 is omitted.

  In FIG. 3, reference numeral 301 denotes an AD converter which converts a shake information signal (angular velocity signal) from the pitch direction gyro section 201 into a digital signal. Reference numeral 302 denotes a high-pass filter (HPF), which is a filter capable of changing the cutoff frequency for cutting the DC component. Reference numeral 303 denotes a phase lead filter (PLF) whose phase can be changed. Reference numeral 304 denotes a high-pass filter (HPF) capable of changing the cutoff frequency. A low-pass filter (LPF) 305 is a filter for converting an angular velocity signal into an angle signal. A cut-off switching unit 306 changes the cut-off frequency of the HPF 304 according to the amount of shake.

  The shake information signal (angular velocity signal) input to the image stabilization control unit 203 is subjected to a series of filter processes and is input to the PID unit 205 as a corrected position control signal.

  FIG. 4 is a block diagram showing an internal configuration of the PID unit 205. Note that the PID unit 206 also has the same internal configuration as the PID unit 205, and a description of the PID unit 206 is omitted.

  In FIG. 4, 401 is an integral compensation unit (Ki), 402 is a proportional compensation unit (Kp), and 403 is a differential compensation unit (Kd). 404 is a switch detector, 405 is a PID switch, 406 and 408 are switches, and 407 is an integral compensation value holder.

  In this PID unit 205, the PID switch 405 operates the switches 406 and 408 by the detection signal of the switch detector 404 to selectively execute PID control or PD control. The switch detector 404 detects the depression of the second switch of the shutter release button and the end of storing image data in the recording unit 116 (end of exposure). During PID control, the changeover switch 406 is closed, the changeover switch 408 is opened, and an integral compensation value that is an output value of the integral compensation unit (Ki) 401 is input to the integral compensation value holder 407. Retained. During PD control, the changeover switch 406 is opened, the changeover switch 408 is closed, and the integral compensation value stored immediately before switching to PD control is read from the integral compensation value holder 407.

  Here, control characteristics of PID control and PD control will be described. PID control is a type of feedback control, and is a control in which an input value is controlled by three elements: a deviation between an output value and a target value, an integral value thereof, and a differential value. In PID control, an operation that changes an input value in proportion to a deviation is called a proportional operation or a P operation. The constant Kp is called a proportional gain.

This proportional action controls the input value as a linear function of the deviation between the output value and the target value. That is, when an input value at a certain time t is x (t), an output value is y (t), and a target value is y0, x (t) = Kp (y (t)? Y0) + x0
It becomes. x0 is an input value necessary to maintain it when y (t) = y0.

If Δx (t) = x (t) −x0 and Δy (t) = y (t) −y0, then Δx (t) = KpΔy (t)
The operation of changing the input value in proportion to the deviation Δy (t) is called a proportional operation or a P operation.

  In proportional control, unless the constant Kp is changed, the input value is always determined with respect to the output value. However, when the control is actually performed, it is sometimes necessary to change the input value for the same output value depending on the surrounding environment. Therefore, in proportional control, the output value cannot reach the target value. The deviation between the output value thus generated and the target value is referred to as residual deviation or offset. So to eliminate residual deviation

  Add the second term as follows. When there is a residual deviation, this term operates to change the input value in proportion to the time that the deviation continues. In other words, if a state with a deviation continues for a long time, the change of the input value is increased and the role of trying to approach the target value is achieved. The operation of changing the input value in proportion to the integrated value of the deviation is referred to as integration operation or I operation. The control method combining the proportional action and the integral action as described above is called PI control. The constant Ki is called an integral gain.

  On the other hand, the output value may fluctuate abruptly due to changes in the surrounding environment or disturbance to the controlled object. Even in such a case, the PI control always tries to bring the output value close to the target value. However, since the I operation has a phase delay characteristic that does not work until a certain amount of time has elapsed, it takes time to return the output value to the target value. Therefore

  Add the third term as follows. This term serves to resist the change by making an input proportional to the magnitude of the change in the case of a sudden change in the output value. The operation of changing the input value in proportion to the differential value of the deviation is called differential operation or D operation. A control method combining the proportional operation, the integral operation, and the differential operation as described above is called PID control. Of these, a control method that combines proportional operation and differential operation is called PD control. In the PD control, since the I operation is not performed, a residual deviation occurs. However, since the phase delay due to the I operation does not occur, the effect of the shake correction operation by the PD control can be higher than that of the PID control.

  The shake correction operation performed in the imaging apparatus configured as described above will be described with reference to FIG.

  FIG. 5 is a flowchart showing a procedure of a shake correction operation performed in the imaging apparatus shown in FIG.

  First, when the power of the imaging apparatus is turned on (S101), PID control is executed (S102). That is, the PID switching device 405 closes the changeover switch 406 and opens the changeover switch 408.

  Then, it is determined whether or not the camera shake correction mode is set to ON by the user on the operation unit 115 (S103). As a result, if the camera shake correction mode is set to ON, the process proceeds to step S106, and if the camera shake correction mode is set to OFF, the process proceeds to step S104.

  In step S104, the shift lens is fixed at the optical axis center position by PID control (S104). As a result, center fixing without offset becomes possible. Thereafter, in step S105, it is determined whether or not the power supply of the imaging apparatus is on. If it is on, the process returns to step S102, and if it is off, the shake correction operation is terminated.

  On the other hand, in step S106, image stabilization control by PID control is performed until the second switch of the shutter release button is turned on. In the image stabilization control by the PID control, the image stabilization performance is slightly inferior to that in the PD control. However, during this period, the image data is not actually recorded in the recording unit 116, but only the image is displayed on the display unit 112. ,No problem.

  Next, it is determined whether or not the second switch of the shutter release button is turned on (S107). If turned on, the process proceeds to step S108, and if it remains off, the process proceeds to step S105.

  In step S108, the integral compensation value holder 407 holds the integral compensation value in the PID control (S108). The PID switch 405 that has received the detection signal from the switch detector 404 opens the switch 406 and closes the switch 408, and as a result, PD control is executed (S109). That is, image stabilization control by PD control is started using the integral compensation value before PD control execution held in the integral compensation value holder 407. Then, an exposure sequence is executed (S110), and when image data storage (exposure) is completed in the recording unit 116 (S111), the process returns to step S102 and PID control is performed again. That is, the PID switch 405 that has received the detection signal from the switch detector 404 closes the switch 406 and opens the switch 408 to perform PID control.

  As described above, in the first embodiment, when the camera shake correction mode is set to OFF, the shift lens is fixed to the optical axis center position from which the offset is removed by PID control. Further, when the camera shake correction mode is set to ON, the image stabilization operation by the PID control having slightly inferior image stabilization performance is performed until the second switch of the shutter release button is pressed. Then, while the second switch is pressed and the exposure sequence is actually executed, the image stabilization operation by the PD control is performed. As a result, image data with a small shake amount is stored on the recording unit 116.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

  Since the configuration of the second embodiment is basically the same as the configuration of the first embodiment, in the description of the second embodiment, the configuration of the first embodiment is used. Only the differences are explained.

  FIG. 6 is a block diagram illustrating a configuration of the PID unit 500 according to the second embodiment.

  The PID unit 500 in the second embodiment corresponds to the PID unit 205 and the PID unit 206 in the first embodiment shown in FIG. 2, and the drive unit 510 includes the drive unit 207 and the PID unit 205 in the first embodiment. It corresponds to the drive unit 208.

  In FIG. 6, 501 is an integral compensation unit (Ki), 502 is a proportional compensation unit (Kp), and 503 is a differential compensation unit (Kd). Reference numeral 504 denotes a switch detector, and 505 denotes a PID switch.

  In this PID unit 500, the PID switch 505 changes the integral compensation coefficient Ki of the integral compensator (Ki) 501 by the detection signal of the switch detector 504, thereby making the degree of integral compensation in PID control variable. The switch detector 504 detects the depression of the second switch of the shutter release button and the end of storing image data on the recording unit 116 (end of exposure).

  A shake correction operation performed in the imaging apparatus according to the second embodiment configured as described above will be described with reference to FIG.

  FIG. 7 is a flowchart showing a procedure of shake correction operation performed in the imaging apparatus shown in FIG.

  First, when the power of the imaging apparatus is turned on (S201), PID control is executed (S202). That is, the PID switch 505 changes the integral compensation coefficient Ki of the integral compensator (Ki) 501 to a value that increases the degree of integral compensation.

  Then, it is determined whether or not the camera shake correction mode is set to ON by the user on the operation unit 115 (S203). As a result, if the camera shake correction mode is set to ON, the process proceeds to step S206, and if the camera shake correction mode is set to OFF, the process proceeds to step S204.

  In step S204, the shift lens is fixed at the optical axis center position by PID control (S204). As a result, center fixing without offset becomes possible. Thereafter, in step S205, it is determined whether or not the power supply of the imaging apparatus is on. If it is on, the process returns to step S202, and if it is off, the shake correction operation is terminated.

  On the other hand, in step S206, image stabilization control by PID control is performed until the second switch of the shutter release button is turned on. In the image stabilization control by the PID control, the image stabilization performance is slightly inferior to that in the PD control. However, during this period, the image data is not actually recorded in the recording unit 116, but only the image is displayed on the display unit 112. ,No problem.

  Next, it is determined whether or not the second switch of the shutter release button is turned on (S207). If turned on, the process proceeds to step S208, and if it remains off, the process proceeds to step S205.

  In step S208, the PID switch 505 changes the integral compensation coefficient Ki of the integral compensator (Ki) 501 to a value that reduces the degree of integral compensation. In this way, by reducing the degree of integral compensation, it becomes closer to the state in which the PD control is performed in a pseudo manner, and the vibration isolation performance can be improved.

  Thereafter, an exposure sequence is executed (S209), and image data is stored (exposed) in the recording unit 116. When the storage of the image data is completed (S210), the value of the integral compensation coefficient Ki is reset to the value before the change (S211), and the process returns to step S202.

  As described above, in the second embodiment, when the camera shake correction mode is set to OFF, the center of the shift lens from which the offset is removed by PID control is performed. Further, when the camera shake correction mode is set to ON, the image stabilization operation by the PID control having slightly inferior image stabilization performance is performed until the second switch of the shutter release button is pressed. On the other hand, while the second switch is pressed and the exposure sequence is actually being executed, the degree of integral compensation is reduced to bring the PID control closer to the PD control. As a result, the image stabilization effect can be enhanced and image data with a small amount of shake can be stored in the recording unit 116.

[Third Embodiment]
Next, a third embodiment of the present invention will be described.

  Since the configuration of the third embodiment is basically the same as the configuration of the first embodiment, in the description of the third embodiment, the configuration of the first embodiment is used. Only the differences are explained.

  The configuration of the PID unit in the third embodiment is the same as the configuration of the PID unit 205 shown in FIG. However, the switch detector 404 in the third embodiment outputs a detection signal to the PID switch 405 when the moving image shooting mode is set by the user on the operation unit 115 and when the moving image shooting is finished. To do.

  FIG. 8 is a flowchart illustrating a procedure of shake correction operation performed in the imaging apparatus according to the third embodiment.

  First, when the power of the imaging apparatus is turned on (S301), the switch detector 404 in the third embodiment determines whether or not the moving image shooting mode is set in the operation unit 115 (S302). As a result, if the moving image shooting mode is set, a detection signal is output to the PID switch 405, and the process proceeds to step S304. On the other hand, if the still image shooting mode is set, the switch detector 404 does not output a detection signal, and the process proceeds to step S303.

  In step S303, a still image shooting sequence is executed. For example, the operations after step S102 shown in FIG. 5 in the first embodiment are executed. Moreover, you may make it perform the operation | movement after step S202 shown in FIG. 7 in the said 2nd Embodiment.

  In step S304, PID control is executed. That is, the PID switching device 405 closes the changeover switch 406 and opens the changeover switch 408.

  Then, it is determined whether or not the camera shake correction mode is set to ON by the user on the operation unit 115 (S305). As a result, if the camera shake correction mode is set to ON, the process proceeds to step S308, and if the camera shake correction mode is set to OFF, the process proceeds to step S306.

  In step S306, the shift lens is fixed at the optical axis center position by PID control. As a result, center fixing without offset becomes possible. Thereafter, in step S307, it is determined whether or not the power supply of the imaging apparatus is on. If it is on, the process returns to step S304, and if it is off, the shake correction operation is terminated.

  On the other hand, in step S308, image stabilization control by PID control is performed until moving image shooting is started. In the image stabilization control by the PID control, the image stabilization performance is slightly inferior to that in the PD control. However, during this period, the image data is not actually recorded in the recording unit 116, but only the image is displayed on the display unit 112. ,No problem.

  Next, in step S309, it is determined whether or not moving image shooting has started. As a result, if moving image shooting is started, the process proceeds to step S310, and if moving image shooting is not started, the process proceeds to step S307.

  In step S310, the integral compensation value holder 407 holds the integral compensation value in PID control. Then, the PID switch 405 opens the switch 406 and closes the switch 408, and as a result, PD control is executed. That is, image stabilization control by PD control is started using the integral compensation value before PD control execution held in the integral compensation value holder 407. In this state, actual moving image shooting is started (S311). When moving image shooting is completed, a detection signal is output from the switch detector 404 to the PID switch 405 (S312). Thereby, it returns to step S304 and PID control is performed again. That is, the PID switch 405 that has received the detection signal from the switch detector 404 closes the switch 406 and opens the switch 408 to perform PID control.

  As described above, in the third embodiment, when the camera shake correction mode is set to OFF at the time of moving image shooting, the lens center is fixed with the offset removed by PID control. In addition, when the camera shake correction mode is set to ON, PD control is performed using the value of the integral compensation value immediately before switching from PID control to PD control, thereby enabling a vibration-proof operation with a small offset. is there.

[Other Embodiments]
Another object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and the computer of the system or apparatus (or CPU, MPU, or the like). Is also achieved by reading and executing the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention. .

  Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, and a DVD. An optical disk such as RW or DVD + RW, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used. Alternatively, the program code may be downloaded via a network.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (Operating System) running on the computer based on the instruction of the program code Includes a case where the functions of the above-described embodiments are realized by performing part or all of the actual processing.

  Furthermore, after the program code read from the storage medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the expanded function is based on the instruction of the program code. This includes a case where a CPU or the like provided on the expansion board or the expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

  Further, by executing the program code read out by the computer, not only the functions of the above-described embodiments are realized, but also the OS running on the computer based on the instruction of the program code is actually Needless to say, the present invention also includes a case in which the functions of the above-described embodiments are realized by performing part or all of the processing and the processing.

  In this case, the program is supplied by downloading directly from a storage medium storing the program or from another computer or database (not shown) connected to the Internet, a commercial network, a local area network, or the like.

1 is a block diagram illustrating a configuration of an imaging apparatus according to a first embodiment of the present invention. It is a block diagram which shows a shift lens drive control part internal structure. It is a block diagram which shows the internal structure of a vibration proof control part. It is a block diagram which shows the internal structure of a PID part. 3 is a flowchart illustrating a procedure of shake correction operation performed in the imaging apparatus according to the first embodiment. It is a block diagram which shows the structure of the PID part in 2nd Embodiment. 10 is a flowchart illustrating a procedure of shake correction operation performed in the imaging apparatus according to the second embodiment. 15 is a flowchart illustrating a procedure of shake correction operation performed in the imaging apparatus according to the third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 103 Shift lens unit 104 Shift lens drive control part 115 Operation part 117 Control part 201 Pitch direction gyro part 202 Yaw direction gyro part 203 Anti-vibration control part 204 Anti-vibration control part 205 PID part 206 PID part

Claims (11)

A switch for starting the exposure operation, an imaging apparatus having a shake correction function for correcting the shake of the captured image by driving the possible optical shake correction lens moving optically position,
Detecting means for detecting a degree of shake applied to the imaging device;
Determining means for determining a target position of the optical shake correction lens according to a degree of shake detected by the detecting means;
Position detecting means for detecting the actual position of the optical shake correction lens;
Feedback control means for performing feedback control so that the actual position detected by the position detection means converges to the target position determined by the determination means;
When the switch is off, the feedback control means executes a first control method for executing the shake correction function by executing proportional control, integral control and differential control, and the switch is turned on from off. Sometimes, before starting the exposure operation , the feedback control means has control means for executing a second control method for executing the shake correction function by executing proportional control and differential control. An imaging apparatus characterized by that. In the first control method, the feedback control unit is configured to determine a proportional compensation coefficient, an integral compensation coefficient, and a derivative based on a difference between an actual position detected by the position detection unit and a target position determined by the determination unit. Determining a compensation coefficient, and generating a command signal for driving the optical shake correction lens based on the three coefficients,
In the second control method, the feedback control means calculates the proportional compensation coefficient and the differential compensation coefficient based on the difference between the actual position detected by the position detection means and the target position determined by the determination means. And determining and driving the optical shake correction lens based on the two coefficients and an integral compensation coefficient obtained when the first control method is executed immediately before the second control method is executed. The imaging device according to claim 1, wherein a command signal for generating the command signal is generated. In the first control method, the feedback control unit is configured to determine a proportional compensation coefficient, an integral compensation coefficient, and a derivative based on a difference between an actual position detected by the position detection unit and a target position determined by the determination unit. Determining a compensation coefficient, and generating a command signal for driving the optical shake correction lens based on the three coefficients,
In the second control method, the feedback control means calculates the proportional compensation coefficient and the differential compensation coefficient based on the difference between the actual position detected by the position detection means and the target position determined by the determination means. The optical shake correction is performed while performing the integration control based on the two coefficients and the integral compensation coefficient set to a value such that the degree of integral compensation is smaller than that of the first control method. The imaging apparatus according to claim 1, wherein a command signal for driving the lens is generated. 2. The image pickup apparatus according to claim 1, wherein the time when the switch is turned on from the time when the switch is turned on is an instruction to start taking a still image or a moving image. The control means controls the feedback control means to switch from the second control method to the first control method when shooting of a still image or a moving image is completed. The imaging device according to claim 4 . A switch for starting the exposure operation, there in shake correction method is applied to an imaging apparatus having a shake correction function for correcting the shake of the captured image by driving the possible optical shake correction lens moving optically location And
A detection step of detecting a degree of shake applied to the imaging device;
A determination step of determining a target position of the optical shake correction lens according to the degree of shake detected in the detection step;
A position detection step of detecting an actual position of the optical shake correction lens;
A feedback control step for performing feedback control so that the actual position detected in the position detection step converges to the target position determined in the determination step;
When the switch is off, in the feedback control step, the first control method for executing the shake correction function by executing proportional control, integral control and differential control is executed, and the switch is turned on from off In some cases, before starting the exposure operation , in the feedback control step, a control step is performed to execute a second control method for executing the shake correction function by executing proportional control and differential control. A shake correction method comprising: In the first control method, the feedback control step includes a proportional compensation coefficient, an integral compensation coefficient, and a derivative based on a difference between the actual position detected in the position detection step and the target position determined in the determination step. Determining a compensation coefficient, and generating a command signal for driving the optical shake correction lens based on the three coefficients,
In the second control method, the feedback control step calculates a proportional compensation coefficient and a differential compensation coefficient based on a difference between the actual position detected in the position detection step and the target position determined in the determination step. And determining and driving the optical shake correction lens based on the two coefficients and an integral compensation coefficient obtained when the first control method is executed immediately before the second control method is executed. The shake correction method according to claim 6, wherein a command signal for generating the command signal is generated. In the first control method, the feedback control step includes a proportional compensation coefficient, an integral compensation coefficient, and a derivative based on a difference between the actual position detected in the position detection step and the target position determined in the determination step. Determining a compensation coefficient, and generating a command signal for driving the optical shake correction lens based on the three coefficients,
In the second control method, the feedback control step calculates a proportional compensation coefficient and a differential compensation coefficient based on a difference between the actual position detected in the position detection step and the target position determined in the determination step. The optical shake correction is performed while performing the integration control based on the two coefficients and the integral compensation coefficient set to a value such that the degree of integral compensation is smaller than that of the first control method. The shake correction method according to claim 6, wherein a command signal for driving the lens is generated. The shake correction method according to claim 6, wherein the time when the switch is turned on from the time when the switch is turned on is an instruction to start shooting a still image or a moving image. In the feedback control step, the control step is controlled to be executed by switching from the second control method to the first control method when shooting of a still image or a moving image is completed. The imaging device according to claim 9 . A switch for starting the exposure operation, the shake correction method is applied to an imaging apparatus having a shake correction function for correcting the shake of the captured image by driving the possible optical shake correction lens moving optically position, A program for causing a computer to execute,
A detection step of detecting a degree of shake applied to the imaging device;
A determination step of determining a target position of the optical shake correction lens according to the degree of shake detected in the detection step;
A position detection step of detecting an actual position of the optical shake correction lens;
A feedback control step for performing feedback control so that the actual position detected in the position detection step converges to the target position determined in the determination step;
When the switch is off, in the feedback control step, the first control method for executing the shake correction function by executing proportional control, integral control and differential control is executed, and the switch is turned on from off In some cases, before starting the exposure operation , in the feedback control step, a control step is performed to execute a second control method for executing the shake correction function by executing proportional control and differential control. A program characterized by having.

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