JP6478504B2 - Imaging apparatus and control method thereof - Google Patents

Description

  The present invention relates to an imaging apparatus and a control method thereof, and more particularly to a camera shake correction technique.

  There is known a camera shake correction technique for detecting a shake of an imaging apparatus and correcting an image shake caused by the shake. The camera shake correction technology includes optical camera shake correction for moving a part of an imaging lens and an image sensor so as to cancel a shake of the apparatus, and electronic camera shake correction for moving an image clipping position.

  It is also known to use both optical image stabilization and electronic image stabilization so that large camera shake can be accommodated. In Patent Document 1, an image shake signal detected by an angular velocity sensor or an acceleration sensor is separated into a high frequency component and a low frequency component, optical camera shake correction is performed based on the high frequency component, and electronic camera shake correction is performed based on the low frequency component. The method of doing is described.

  Patent Document 2 describes a method of selectively using electronic camera shake correction when the angular velocity of the apparatus is equal to or less than a set value, and optical camera shake correction when the angular velocity is equal to or greater than a certain value, and expanding the correction range. Has been.

JP 2010-4370 A Japanese Patent No. 2803072 (paragraphs 0057 to 0060)

  While optical camera shake correction can always be executed, electronic camera shake correction cannot correct camera shake during exposure because of camera shake correction by image clipping. Therefore, in the method of Patent Document 1, only optical camera shake correction can be used during exposure in still image shooting during moving image shooting, and only high-frequency components of camera shake can be corrected. There is also a problem caused by the external force described above.

  Further, the method of Patent Document 2 has a problem in that the image is disturbed due to overshooting of the optical image stabilization drive at the boundary where the electronic image stabilization and the optical image stabilization are switched.

  The present invention has been made in view of the above-described problems of the prior art, and in an imaging apparatus capable of using both optical camera shake correction and electronic camera shake correction, and a control method thereof, a favorable correction effect in which the influence of disturbance is suppressed. It aims at realizing.

The above-described object is an imaging apparatus, and includes a first calculation unit that calculates a first correction amount for correcting image blur due to movement of the device, and a predetermined high-frequency component of the first correction amount. And a second correction amount obtained based on a difference between the first correction amount and the position of the machine element. A second correction unit that electronically corrects the image blur by changing the cutout position of the image on the basis thereof, and a third correction unit that corrects the high-frequency component of the first correction amount according to the disturbance applied to the imaging device. A second calculating unit that calculates a correction amount; and a detecting unit that detects an acceleration of the imaging apparatus. The first correcting unit drives the mechanical element based on the third correction amount, and Calculating means for converting acceleration into disturbance thrust, and And amplifying means for applying a gain, calculating a third correction amount by correcting a high-frequency component of the first correction amount using a disturbance thrust applied with a gain, and displaying an image of the imaging optical system of the imaging apparatus. When the angle is larger than the predetermined first field angle, the gain is made larger than the reference value, and when the angle is smaller than the second field angle smaller than the first field angle, the gain is made smaller than the reference value. This is achieved by the imaging device.

  According to the present invention, it is possible to realize a good correction effect in which the influence of disturbance is suppressed in an imaging apparatus capable of using both optical camera shake correction and electronic camera shake correction and a control method thereof.

1 is a block diagram showing a functional configuration example of a digital camera as an example of an imaging apparatus according to an embodiment Block diagram for explaining a camera shake correction operation in the first embodiment Block diagram for explaining a camera shake correction operation in the second embodiment Schematic diagram modeling machine elements controlled by optical image stabilization in the embodiment The figure for demonstrating operation | movement of the disturbance observer in 3rd Embodiment. A block diagram for explaining a camera shake correction operation in the third embodiment

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, a digital camera as an example of an imaging apparatus according to an embodiment of the present invention will be described. However, the present invention is not limited to an apparatus mainly having a photographing function such as a digital camera, but can be applied to any apparatus having an imaging apparatus that can use both optical camera shake correction and electronic camera shake correction. Examples of such devices include mobile phones (including smart phones), game machines, personal computers, tablet terminals, car navigation systems, drive recorders, robots, and the like.

  FIG. 1 is a block diagram illustrating a functional configuration example of a digital camera 100 according to an embodiment of the present invention. The digital camera 100 can capture and record still images and moving images, and can use both optical camera shake correction and electronic camera shake correction. In this embodiment, it is assumed that the mechanical component driven by optical image stabilization is an image stabilization lens (shift lens or tilt lens). However, the image sensor (or a module that holds the lens and the image sensor) is driven. May be.

  In FIG. 1, the imaging optical system 120 includes a zoom unit 101, an aperture / shutter unit 103, a camera shake correction unit 105, and a focus unit 107, and forms an optical image on an imaging surface of an imaging element included in the imaging unit 109. . The zoom unit 101 is a lens group that is movable in the optical axis direction for changing the focal length (view angle) of the imaging optical system. The aperture / shutter unit 103 is a mechanical shutter having an aperture function. The camera shake correction unit 105 includes a mechanical element movable in the optical path for optically correcting image blur. The mechanical element may be, for example, a camera shake correction lens or an image sensor that can move in a direction orthogonal to the optical axis or in a direction inclined with respect to the optical axis. The focus unit 107 has a focus lens that is movable in the optical axis direction for adjusting the distance at which the imaging optical system 120 is focused. Note that the imaging optical system 120 may include a fixed lens (not shown).

  The zoom unit 101, the aperture / shutter unit 103, the camera shake correction unit 105, and the focus unit 107 each have a mechanical movable member. These movable members are driven by the zoom drive control unit 102, the aperture / shutter drive control unit 104, the camera shake correction control unit 106, and the focus drive control unit 108 according to the control of the system control unit 119.

  The imaging unit 109 includes an imaging device in which a plurality of pixels are arranged, and converts a subject image formed by the imaging optical system 120 into an electrical signal for each pixel. The imaging signal processing unit 110 converts the electrical signal output from the imaging unit 109 into an image signal by applying processing such as A / D conversion, white balance adjustment, and color interpolation. The imaging signal processing unit 110 further has an electronic image stabilization function by changing the cutout position of the image signal based on the electronic image stabilization amount calculated by the system control unit 119 according to the drive amount of the image stabilization unit 105. Realize.

  The image signal processing unit 111 processes the image signal output from the imaging signal processing unit 110 according to the application. For example, the image signal processing unit 111 resizes the image signal in accordance with the display resolution or encodes it for recording.

  The display unit 112 displays the display image signal output from the image signal processing unit 111 based on the control of the system control unit 119. The power supply unit 113 supplies power to necessary ones of the functional blocks of the digital camera 100 according to an operation mode and a user instruction. The external input / output terminal unit 114 is a connector and interface group for connecting an external device to communicate signals and data. Note that in the case of performing wireless communication with an external device, the external input / output terminal unit 114 may include an antenna.

  The operation unit 115 is an input device group used by a user to input instructions and settings to the digital camera 100. Typically, a button, a switch, a touch panel, or the like is used, but a voice, line of sight, or the like may be used. In this embodiment, the image stabilization switch for instructing the user to turn on / off the camera shake correction function, the release button for instructing to start and start shooting of still images, and instructing to start and stop shooting of moving images The operation unit 115 includes a moving image recording button. The release button has a first switch SW1 that is turned on when pressed halfway and a second switch SW2 that is turned on when pressed fully. When the first switch SW1 is turned on, shooting preparation is started, and when the second switch SW2 is turned on, shooting is started. Each is instructed to the system control unit 119. The moving image recording switch instructs the system control unit 119 to start moving image shooting when pressed while no moving image is recorded, and to stop recording (end) when pressed during moving image recording. If the release button is operated during moving image recording, still image shooting during moving image recording is executed.

In addition, the digital camera 100 according to the present embodiment has a plurality of operation modes including a shooting mode and a playback mode, and can specify an operation mode through the operation unit 115. When the reproduction mode is designated, the system control unit 119 turns off the camera shake correction function.
The operation unit 115 includes a zoom switch for changing the focal length (view angle) of the imaging optical system 120, and the system control unit 119 responds to the operation direction of the zoom switch through the zoom drive control unit 102. The zoom unit 101 is driven in the selected direction.

  The storage unit 116 is, for example, a detachable semiconductor memory card, and stores still images, moving images (including sound) and the like taken with the digital camera 100. Note that the storage unit 116 may use a storage device other than the nonvolatile memory, or may include a storage device fixed to the digital camera 100.

  The angular velocity detection unit 117 includes an angular velocity sensor, and detects the movement (camera shake amount) of the digital camera 100 based on the output of the angular velocity sensor. The acceleration detection unit 118 includes an acceleration sensor, and detects acceleration applied to the digital camera 100 based on the output of the acceleration sensor. The system control unit 119 includes one or more programmable processors such as a CPU and an MPU, a ROM, and a RAM. The program stored in the ROM is expanded into the RAM and executed to execute the operation of the functional blocks of the digital camera 100. Control.

Next, the operation of the digital camera 100 will be described.
When the camera shake correction function is instructed to be turned ON by the image stabilization switch of the operation unit 115, the system control unit 119 instructs the camera shake correction control unit 106 to perform the image stabilization operation, and the camera shake correction control unit 106 that has received this instruction is turned off. Anti-vibration operation is performed until the instruction is given. In addition, the operation unit 115 includes a camera shake correction mode switch that can select a mode for performing image stabilization only by optical camera shake correction and a mode for performing image stabilization by using both optical camera shake correction and electronic camera shake correction. In the case of only the optical camera shake correction mode, the reading position of the imaging unit 109 is constant, and widening shooting can be supported by widening the reading range accordingly. On the other hand, when the image stabilization mode is selected by the combination of optical image stabilization and electronic image stabilization, the readout position is changed in accordance with the image stabilization amount instead of the cutout range of the imaging unit 109. Can handle camera shake.

  When the first switch SW1 of the release button of the operation unit 115 is turned on, the system control unit 119 starts a still image shooting preparation operation. Specifically, the system control unit 119 moves the focus unit 107 through the focus drive control unit 108 so that the imaging optical system 120 is focused on a subject in a focus detection region such as an AF frame. This automatic focus detection operation can be performed using a known method such as an image plane phase difference detection method or a contrast detection method based on image data used for so-called live view display. Further, a phase difference detection method based on the output of a phase difference detection sensor provided in addition to the image sensor may be used. The system control unit 119 also performs automatic exposure control using a known method, and determines shooting conditions (aperture value, shutter speed, shooting sensitivity, etc.) for obtaining appropriate exposure. At this time, the system control unit 119 may drive the aperture / shutter unit 103 through the aperture / shutter drive control unit 104 so that the determined aperture value is obtained.

  When the second switch SW2 is turned on, the system control unit 119 starts a still image shooting operation. The system control unit 119 drives the aperture / shutter unit 103 through the aperture / shutter drive control unit 104 based on the determined photographing condition. Further, the system control unit 119 acquires the image signal for recording by processing the image signal generated by the imaging unit 109 by the imaging signal processing unit 110 and the image signal processing unit 111. The system control unit 119 stores the image signal for recording in the storage unit 116 in a predetermined file format.

  When the moving image recording switch is pressed, moving image shooting and recording at a predetermined frame rate is started. The shooting and recording operations for each frame are basically the same as those for still image shooting except for the encoding format. Note that the AF operation performed during moving image shooting may be performed using a known TV-AF method or the like.

  FIG. 2 is a block diagram showing in more detail the functional configuration related to the camera shake correction function of the digital camera 100. Since the same operation is performed on the data in the pitch (tilt) direction and the yaw (pan) direction, only one direction will be described. In addition, even if the functional blocks included in the system control unit 119 in FIG. 2 are realized by executing software by the programmable processor included in the system control unit 119, at least a part of the functional blocks is realized by hardware such as ASIC or PLD. May be.

The angular velocity detection unit 117 uses, for example, a gyro as an angular velocity sensor, and outputs the angular velocity as a voltage. The AD conversion unit 201 of the system control unit 119 converts the voltage output from the angular velocity detection unit 117 into digital data at a predetermined sampling rate.
The first blur correction amount calculation unit 202 calculates a correction amount (first correction amount) for correcting image blur from the angular velocity data output from the AD conversion unit 201. Specifically, the optical image stabilization amount calculation unit 202 applies a high-pass filter to the angular velocity data, removes the offset component, integrates and converts the angular data to angular data, and multiplies the coefficient by a coefficient called sensitivity. Is converted into a shake correction amount.

  The low pass filter (LPF) 203 passes only the low frequency component of the shake correction amount output from the first shake correction amount calculation unit 202. The cutoff frequency of the LPF 203 may be variable, and can be determined according to the relationship between the movable range of a mechanical element (shift lens) used for optical camera shake correction and the frequency component and amplitude of the shake measured in advance. The subtractor 211 subtracts the output of the low-pass filter 203 from the shake correction amount and outputs a high frequency component of the camera shake correction amount. The LPF 203 and the subtractor 211 constitute filter means for extracting a high frequency component of the camera shake correction amount.

  The PID control unit 204 receives the high-frequency component of the camera shake correction amount and the position of the camera shake correction unit (camera shake correction lens) 105 as input, and generates a camera shake correction amount by known PID control. Then, the PID control unit 204 supplies the camera shake correction amount to the optical camera shake correction control unit 106 and controls the position of the camera shake correction lens through the drive unit 205. Specifically, the PID control unit 204 uses the difference between the correction lens position to be realized by the correction amount given to the drive unit 205 and the correction lens position input from the AD conversion unit 207 as a deviation. I do. In addition, the drive unit 205 converts the camera shake correction amount into a current that operates, for example, an actuator that drives the camera shake correction unit 105. The PID control unit 204 and the drive unit 205 constitute a first correction unit.

  A drive unit 205 included in the optical image stabilization control unit 106 converts the image stabilization amount output from the PID control unit 204 into a voltage, and supplies a current for driving the image stabilization unit 105. The position detection unit 206 detects the position of the camera shake correction lens included in the camera shake correction unit 105 and outputs it as an analog voltage signal (position detection signal) having a value corresponding to the position. The AD conversion unit 207 of the system control unit 119 converts an analog voltage representing the position of the camera shake correction lens into digital data, and outputs the digital data to the PID control unit 204.

  Thus, in this embodiment, optical camera shake correction is performed based on the detected high-frequency component of the camera shake amount. Note that the cutoff frequency of the low-pass filter 203 may be changed. For example, when the movable range of a lens or the like that is driven by optical camera shake correction is changed, the cut-off frequency may be increased as the movable range is narrowed, and the correction may be specialized for a smaller range. In addition, when the exposure time per frame at the time of moving image shooting is changed, the longer the exposure time, the more the optical camera shake correction is required. Therefore, the cutoff frequency of the low-pass filter 203 may be lowered. This is because, as described above, camera shake occurring during exposure cannot be corrected by electronic camera shake correction.

  Further, when still image shooting is performed by pressing the release button (including still image shooting during moving image recording), electronic camera shake correction cannot be performed during still image exposure, and only camera shake correction of only high-frequency components can be performed. Therefore, the system control unit 119 supplies the output of the first blur correction amount calculation unit 202 directly to the PID control unit 204 instead of the output of the subtractor 211 only during still image exposure. Alternatively, the PID control unit 204 generates a correction amount using the output of the first blur correction amount calculation unit 202 instead of the output of the subtractor 211 during still image exposure. As a result, a correction amount for correcting all the frequency components of the detected camera shake using the optical camera shake correction function is generated, and the camera shake correction capability during still image exposure can be improved.

  The operation of the electronic image stabilization function will be described with reference to FIG. The blur correction amount output from the first blur correction amount calculation unit 202 is also input to the subtractor 212. The subtractor 212 subtracts the position of the camera shake correction lens output from the position detection unit 206 from the camera shake correction amount output from the first camera shake correction amount calculation unit 202. The second shake correction amount calculation unit 208 multiplies the low-frequency component shake correction amount (blur remaining amount) output from the subtractor 212 and not corrected by the optical camera shake correction function by a coefficient, and performs electronic camera shake correction. Is converted into the correction amount (second correction amount) of the image cut-out position used in the above. In the imaging signal processing unit 110, the image processing unit 210 converts the analog image signal output from the imaging unit 109 into a digital image signal by applying processing such as A / D conversion, white balance adjustment, and color interpolation. . The electronic camera shake correction unit 209 cuts out a digital image signal at a position based on the correction amount supplied from the second camera shake correction amount calculation unit 208 and outputs the digital image signal to the image signal processing unit 111. The second shake correction amount calculation unit 208 and the electronic camera shake correction unit 209 constitute a second correction unit.

  According to the present embodiment, a high-frequency component of a correction amount for correcting the detected shake of the imaging device by the optical camera shake correction function is corrected by the optical camera shake correction function, and the correction amount and the machine used for the optical camera shake correction are used. The difference from the position of the element is corrected using an electronic image stabilization function. In the case of a configuration in which the detected shake is separated into a high-frequency component and a low-frequency component and is corrected independently by the optical image stabilization function and the electronic image stabilization function, the response delay of driving the mechanical elements used for the optical image stabilization function The position error due to disturbance remains uncorrected. However, according to the configuration of the present embodiment, since the frequency components that could not be corrected by the shake due to the optical shake correction are corrected by the electronic shake correction, the influence of disturbance and response delay is covered by the electronic shake correction. The correction capability can be improved.

● (Second Embodiment)
Next, a second embodiment of the present invention will be described. Also in the first embodiment, it is possible to suppress a decrease in accuracy of position control due to a response delay or disturbance in driving of a mechanical element used for the optical camera shake correction function. However, it is difficult to cover the deterioration in accuracy caused by a large disturbance that occurs when shooting while walking or running with electronic camera shake correction, and image blur cannot be completely corrected. The disturbance is an external action that disturbs the control, and the disturbance to the optical camera shake correction of the present embodiment is an external force that disturbs the position of a mechanical element (such as a camera shake correction lens) driven by the drive unit 205. .

  In the present embodiment, a configuration for suppressing a reduction in correction accuracy when a large disturbance is applied is provided by enhancing the resistance of optical camera shake correction to the disturbance. FIG. 3 is a block diagram showing a functional configuration related to the camera shake correction function of the digital camera according to the present embodiment, and the same reference numerals are assigned to the same components as those in FIG.

  In the present embodiment, the disturbance is detected using the acceleration detection unit 118. There are various disturbances (external forces) applied to the digital camera, but a large acceleration disturbance occurs when shooting while walking or running. This disturbance moves as the camera shake correction unit 105 (camera shake correction lens) and is recorded as image shake. In the present invention, the blur component that could not be corrected by the optical camera shake correction function is a configuration that is corrected by the electronic camera shake correction function, but the electronic camera shake correction corrects the camera shake by changing the cutout position of the image. High-frequency blur occurring within one frame period of the image cannot be corrected. Disturbance compensation is performed based on the disturbance thrust calculated by mathematical modeling of the controlled object.However, since the actual controlled object generally includes nonlinear elements, the disturbance thrust based on the mathematical model that has been linearized easily. Cannot be fully compensated for.

For this reason, in this embodiment, the compensation effect is enhanced by performing in parallel disturbance compensation by electronic camera shake correction and disturbance compensation by optical camera shake correction. FIG. 4 is a diagram schematically illustrating a mechanical element (camera correction lens) to be controlled included in the camera shake correction unit 105 using a secondary system spring mass damper model. The lens moving part weight is M [kg], the spring constant is k [N / m], the damping coefficient is D [N · s / m], the lens driving displacement is x (t) [m], and the force applied to the lens Let u (t) [N] be the following equation from the equation of motion.

This formula is Laplace transformed and the controlled object is expressed by the transfer function H (s) as follows. However, H (s) is a transfer function of a mathematical model of the camera shake correction unit 105 to be controlled.

Thereby, the camera shake correction lens can be approximated as a control target of the secondary system. The force u (t) applied to the lens here depends on the driving force r (t) [N] applied to the actuator or the like by the lens driving command signal (driving current) output from the driving unit 205, acceleration disturbance, etc. This is a composition of external force d [N] and is expressed by the following equation.
u (t) = r (t) + d (t)

  If d (t) is limited to acceleration disturbance, it can be compensated if the acceleration of the digital camera 100 can be detected. Therefore, the acceleration detection unit 118 is used to detect the acceleration of the digital camera 100. The AD conversion unit 311 converts the acceleration represented by the analog signal detected by the acceleration detection unit 118 into digital data.

  The disturbance thrust converting unit 312 converts the detected acceleration into a disturbance thrust applied to the digital camera 100 (camera shake correcting unit 105). The band-pass filter (BPF) 313 has a characteristic of passing a predetermined frequency component of disturbance generated during shooting while walking or running. The output of the BPF 313 is input to the amplifier 314, and a disturbance compensation gain (amplification factor) is applied. The disturbance compensation gain may be dynamically changed according to the state at the time of shooting, such as the magnitude of the disturbance amplitude, so that overcorrection does not occur due to disturbance compensation.

When performing disturbance compensation assuming walking shooting and running shooting, when the angle of view of the imaging optical system 120 is larger than the predetermined first angle of view (wide angle side), the disturbance compensation gain is set larger than the reference value, and the second When the angle of view is smaller (telephoto side), the disturbance compensation gain may be smaller than the reference value. Further, as a camera shake correction mode of the digital camera 100, the disturbance compensation gain may be set larger than the reference value if a mode for expanding the correction range of the electronic camera shake correction instead of narrowing the shooting angle of view is set. The disturbance thrust finally obtained by applying the disturbance compensation gain is subtracted from the output of the PID control unit 204 in the subtractor 315, thereby calculating a correction amount (third correction amount ) that compensates for the disturbance. Thereby, it is possible to compensate for the influence of the optical camera shake correction due to the disturbance, and to suppress the decrease in the optical camera shake correction capability due to the disturbance. For this reason, it is possible to correct blur components that cannot be corrected by optical camera shake correction using electronic camera shake correction, and it is possible to improve the overall camera shake correction capability. In the present embodiment, the disturbance thrust conversion unit 312, the BPF 313, the amplifier 314, and the subtractor 315 constitute a second calculation unit.

  The operation in the case of still image shooting may be the same as that of the first embodiment, but the cutoff frequency of the BPF 313 is changed only during exposure for still image shooting in order to compensate for the phase lag and phase advance of the BPF 313. . In addition, since electronic image stabilization cannot be used during still image exposure, even when the disturbance compensation gain is reduced to prevent overcorrection during movie shooting, the exposure period will be Only change to a larger value.

  As described above, according to the present embodiment, in addition to the effects of the first embodiment, even when a large disturbance is applied, such as when shooting is performed while walking or running, a favorable camera shake correction is realized. be able to.

● (Third embodiment)
In the second embodiment, the disturbance is measured by using the acceleration detection unit 118 (acceleration sensor) to compensate for the disturbance. In the present embodiment, a configuration for realizing disturbance compensation without using the acceleration detection unit 118 is provided.

  Specifically, the disturbance compensation is performed using the acceleration estimated using the disturbance observer using the inverse model of the mathematical model to be controlled in the same manner as the output of the acceleration detection unit in the second embodiment.

First, a general disturbance observer will be described with reference to FIG. The values in FIG. 5 are as follows.
R: Input to the controlled object 501 (before receiving disturbance)
X: Output of the control target 501
G (s): Transfer function of the controlled object 501
D: Disturbance applied to the controlled object 501.
H (s): The transfer function of the controlled object 501 obtained theoretically.
E: Estimated disturbance.

  In general, when the controlled object has a mechanical structure, the transfer function G (s) of the controlled object has a nonlinear component, so it is not possible to match the theoretically calculated transfer function H (s) with G (s). difficult. Therefore, although G (s) ≈H (s), strictly speaking, G (s) ≠ H (s). The input to the control object 501 is obtained by adding the input r and disturbance d from the control unit by the adder 503. In the control object 501, an output x according to the addition result is obtained. By inputting the output x to the theoretically obtained inverse model 502 (1 / H (s)) of the transfer function H (s) of the controlled object 501, the estimated signal of the actual input signal is input to the controlled object 501. can get.

  As described above, since G (s) ≈H (s), the estimated signal obtained does not exactly match the actual input signal, but is useful for estimating the disturbance. Since the estimated input signal is an estimated signal of the sum of the input r and the disturbance d from the control unit, the estimated signal of the disturbance d is obtained by subtracting the input signal r from the actual control unit by the subtractor 505. It is done. By subtracting the estimated disturbance e by the subtractor 504 before the input r from the control unit is input to the controlled object 501, the actual disturbance d can be compensated. In FIG. 5, the disturbance observer includes an inverse model 502 having a transfer function “1 / H (s)” and a subtracter 505. The estimation accuracy of the disturbance observer greatly depends on how accurately the transfer function H (s) of the inverse model 502 of the control target 501 can approximate the transfer function G (s) of the control target.

  FIG. 6 is a block diagram showing a functional configuration related to the camera shake correction function of the digital camera according to the present embodiment. The same reference numerals are given to the same components as those in FIG. FIG. 6 is a diagram that realizes disturbance compensation by adding a disturbance observer to the configuration of FIG.

  The camera shake correction unit 105 is driven by a drive signal (current) output from the drive unit 205. At this time, when disturbance (mainly acceleration disturbance) is applied to the digital camera 100, the disturbance is added to the movement of the camera shake correction unit 105 that is the control target. The movement of the camera shake correction unit 105 in which the movement by the control signal and the movement by the disturbance are added is detected by the position detection unit 206. The position detection signal output from the position detection unit 206 is converted into digital data by the AD conversion unit 207 and output to the disturbance observer 611 and the PID control unit 204.

As described with reference to FIG. 5, the disturbance observer 611 removes an AD-converted position detection signal (position of the camera shake correction lens reflecting the disturbance) and the estimated disturbance used for position control of the camera shake correction lens. The disturbance (acceleration) is estimated from the corrected amount . The estimated disturbance is input to the subtractor 315 through the bandpass filter 313 and the amplifier 314 and is subtracted from the correction amount output from the PID control unit 204 to compensate for the disturbance, similarly to the output of the disturbance thrust conversion unit 312 in FIG. Is done. In the present embodiment, the disturbance observer 611, the BPF 313, the amplifier 314, and the subtractor 315 constitute a second calculation unit.

  In the present embodiment, the compensation by the disturbance observer is described simply by a deterministic system. However, the disturbance may be estimated by using a Kalman filter by optimal control considering observation noise.

  According to the present embodiment, even if the configuration does not include an acceleration sensor, it is possible to perform camera shake correction processing in consideration of disturbance, and in the case where a large disturbance is applied, a better correction effect than in the first embodiment. Can be realized.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program. It is a process to be executed.

DESCRIPTION OF SYMBOLS 105 ... Correction lens unit, 106 ... Anti-vibration control part, 109 ... Imaging part, 110 ... Imaging signal processing part, 113 ... Power supply part, 112 ... Display part, 115 ... Operation part, 117 ... Angular velocity detection part, 118 ... Acceleration detection Part, 119 ... system control part

Claims (7)

An imaging device,
First calculating means for calculating a first correction amount for correcting image blur due to movement of the apparatus;
First correction means for optically correcting image blur by driving a mechanical element based on a predetermined high-frequency component of the first correction amount;
A second correction that electronically corrects image blur by changing the cutout position of the image based on a second correction amount obtained based on the difference between the first correction amount and the position of the machine element. Means,
Second calculation means for calculating a third correction amount obtained by correcting the high-frequency component of the first correction amount according to a disturbance applied to the imaging device;
Detecting means for detecting acceleration of the imaging device;
The first correction means drives the mechanical element based on the third correction amount,
The second calculating means comprises:
Conversion means for converting the acceleration into a disturbance thrust;
Amplifying means for applying a gain to the disturbance thrust,
Calculating the third correction amount by correcting the high-frequency component of the first correction amount using the disturbance thrust applied with the gain;
When the angle of view of the image pickup optical system of the image pickup device is larger than the predetermined first angle of view, the gain is set larger than a reference value, and when the angle of view is smaller than the second angle of view smaller than the first angle of view. Making the gain smaller than the reference value;
An imaging apparatus characterized by that.   An imaging device comprising:
  First calculating means for calculating a first correction amount for correcting image blur due to movement of the apparatus;
  First correction means for optically correcting image blur by driving a mechanical element based on a predetermined high-frequency component of the first correction amount;
  A second correction that electronically corrects image blur by changing the cutout position of the image based on a second correction amount obtained based on the difference between the first correction amount and the position of the machine element. Means,
  Second calculating means for calculating a third correction amount obtained by correcting the high-frequency component of the first correction amount according to a disturbance applied to the imaging device;
  The first correction means drives the mechanical element based on the third correction amount,
  The second calculating means comprises:
    Conversion means for converting acceleration estimated from the third correction amount and the position of the machine element into disturbance thrust;
    Amplifying means for applying a gain to the disturbance thrust,
    Calculating the third correction amount by correcting the high-frequency component of the first correction amount using the disturbance thrust applied with the gain;
    When the angle of view of the image pickup optical system of the image pickup device is larger than the predetermined first angle of view, the gain is set larger than a reference value, and when the angle of view is smaller than the second angle of view smaller than the first angle of view. Making the gain smaller than the reference value;
An imaging apparatus characterized by that. Said second calculation means, said second if the setting to widen the correction range of the correction means is the according to the gain in claim 1 or 2, characterized in that greater than the reference value Imaging device. Said second calculating means, the image pickup apparatus according to any one of in the still image exposure of the gain than in the movie shooting claim 1, characterized in that the greatly 3. The apparatus further includes a filter unit that extracts the high-frequency component by removing the low-frequency component of the first correction amount output from the first calculation unit and supplies the high-frequency component to the first correction unit. The imaging device according to any one of claims 1 to 4 . A first calculation step in which a first calculation unit of the imaging apparatus calculates a first correction amount for correcting image blur due to movement of the apparatus;
A first correction step in which a first correction unit of the imaging apparatus optically corrects image blur by driving a mechanical element based on a predetermined high-frequency component of the first correction amount; ,
By the second correcting means of the image pickup apparatus changes the cutout position of the image based on the second correction amount obtained based on the difference between the position of the machine element and the first correction amount, the electronic A second correction step for correcting image blur automatically,
A second calculation step in which a second calculation unit of the imaging device calculates a third correction amount obtained by correcting the high-frequency component of the first correction amount according to a disturbance applied to the imaging device;
A detecting step for detecting the acceleration of the imaging device, wherein the detection means of the imaging device comprises:
In the first correction step, the first correction means drives the mechanical element based on the third correction amount,
The second calculation step includes:
A converting step in which the converting means of the imaging device converts the acceleration into a disturbance thrust;
An amplification step of applying gain to the disturbance thrust, the amplification means of the imaging device,
In the second calculation step, the second correction unit includes:
Calculating the third correction amount by correcting the high-frequency component of the first correction amount using the disturbance thrust applied with the gain;
When the angle of view of the image pickup optical system of the image pickup device is larger than the predetermined first angle of view, the gain is set larger than a reference value, and when the angle of view is smaller than the second angle of view smaller than the first angle of view. Making the gain smaller than the reference value;
And a method of controlling the imaging apparatus.   A first calculation step in which a first calculation unit of the imaging apparatus calculates a first correction amount for correcting image blur due to movement of the apparatus;
  A first correction step in which a first correction unit of the imaging apparatus optically corrects image blur by driving a mechanical element based on a predetermined high-frequency component of the first correction amount; ,
  The second correction unit of the imaging apparatus changes the cutout position of the image based on the second correction amount obtained based on the difference between the first correction amount and the position of the mechanical element, thereby A second correction step for correcting image blur automatically,
  A second calculation step in which a second calculation unit of the imaging device calculates a third correction amount obtained by correcting the high-frequency component of the first correction amount according to a disturbance applied to the imaging device; Have
  In the first correction step, the first correction means drives the mechanical element based on the third correction amount,
  The second calculation step includes:
    A conversion step in which the conversion means of the imaging apparatus converts the acceleration estimated from the third correction amount and the position of the mechanical element into a disturbance thrust;
    An amplification step of applying gain to the disturbance thrust, the amplification means of the imaging device,
  In the second calculation step, the second correction unit includes:
    Calculating the third correction amount by correcting the high-frequency component of the first correction amount using the disturbance thrust applied with the gain;
    When the angle of view of the image pickup optical system of the image pickup device is larger than the predetermined first angle of view, the gain is set larger than a reference value, and when the angle of view is smaller than the second angle of view smaller than the first angle of view. Making the gain smaller than the reference value;
And a method of controlling the imaging apparatus.

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