JP2016167801A - Imaging device, imaging method and imaging program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device that can properly correct reduction of the peripheral light quantity due to blurring correction.SOLUTION: A digital camera 1 includes an optical system comprising a plurality of lenses including an OIS lens 220 for correcting an image blur, and CCD110 for capturing a subject image formed by an optical system. The digital camera 1 includes an OIS driver 221 for performing image blur correction by moving the OIS lens 220 within a plane perpendicular to the optical axis, a CCD driver 181 for performing image blur correction by moving the CCD110 within a plane perpendicular to the optical axis, and a camera controller 140. The camera controller 140 corrects the image captured by the CCD 110, and changes the correction amount of the peripheral light amount of the image captured by CCD 110 when the image blur correction based on the OIS driver 221 and the image blur correction based on the CCD driver 181 are switched to each other.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an imaging apparatus, an imaging method, and an imaging program having a camera shake correction function in both a lens and a camera body.

  2. Description of the Related Art Conventionally, there is an imaging apparatus equipped with detection means (such as a gyro sensor) that detects a shake of the own apparatus. In the case of a camera with an interchangeable lens, detection means (such as a gyro sensor) for detecting a shake of the imaging device is provided on at least one of the interchangeable lens and the camera body (see, for example, Patent Document 1). In the case where the detection unit is provided in the interchangeable lens, the position of the blur correction lens provided in the interchangeable lens is shifted based on the detection result of the detection unit. On the other hand, when the detection means is provided in the camera body, the position of the image sensor (image sensor) provided in the camera body is shifted based on the detection result of the detection means.

  In such an imaging apparatus, vibrations in a frequency band of about 1 to 10 Hz due to camera shake of the photographer are detected by the detection means, and based on the detection result, the lenses in the interchangeable lens and the imaging sensor in the camera body are detected. By driving either or both, the influence of blur in the captured image is reduced.

JP 2009-251492 A

  A subject image projected onto an image sensor through a lens in the image pickup apparatus has a characteristic that the amount of light decreases toward the periphery of the image sensor. When the correction lens and image sensor are shifted according to the blur of the imaging device to reduce the effect of blur in the captured image, the subject projected on the image sensor due to the shift by the correction lens or the shift of the image sensor In the image, the amount of light further decreases toward the periphery of the image sensor. For this reason, there has been a problem that the quality of the photographed image is lowered. The present disclosure relates to an image pickup apparatus that reduces the influence of blur during shooting by shifting a correction lens or an image pickup device, and the quality of a shot image due to a reduction in the subject image projected on the image pickup device around the image pickup device. An object is to prevent a decrease and provide a good captured image. Moreover, it aims at providing the imaging method and imaging program.

  An imaging device according to the present disclosure includes an optical system, a lens driving unit, an imaging element, an element driving unit, and a control unit. The optical system includes a plurality of lenses including a correction lens for correcting image blur. The lens driving unit performs image blur correction by moving the correction lens in a plane perpendicular to the optical axis. The imaging device captures a subject image formed by the optical system. The element driving unit performs image blur correction by moving the imaging element in a plane perpendicular to the optical axis. The control unit corrects the image captured by the image sensor, and corrects the peripheral light amount of the image captured by the image sensor when switching between image blur correction by the lens driver and image blur correction by the element driver. Change the amount.

  The imaging method of the present disclosure includes an imaging step, a first image blur correction step, a second image blur correction step, and an image correction step. In the imaging step, a subject image formed by an optical system including a correction lens is captured by an imaging element. In the first image blur correction step, the image blur is corrected by moving the correction lens in a plane perpendicular to the optical axis. In the second image blur correction step, the image blur is corrected by moving the image sensor in a plane perpendicular to the optical axis. The image correction step corrects the image picked up by the image sensor, and when the image blur correction by the first image blur correction step and the image blur correction by the second image blur correction step are switched to each other, Change the amount of light correction.

  The imaging program of the present disclosure is an imaging program for causing a computer to execute an imaging step, a first image blur correction step, a second image blur correction step, and an image correction step. In the imaging step, a subject image formed by an optical system including a correction lens is captured by an imaging element. In the first image blur correction step, the image blur is corrected by moving the correction lens in a plane perpendicular to the optical axis. In the second image blur correction step, the image blur is corrected by moving the image sensor in a plane perpendicular to the optical axis. The image correction step corrects the image picked up by the image sensor, and when the image blur correction by the first image blur correction step and the image blur correction by the second image blur correction step are switched to each other, Change the amount of light correction.

  According to the present disclosure, it is possible to prevent a deterioration in quality of a captured image caused by a subject image projected on the image sensor in the imaging apparatus being reduced around the image sensor, and provide a good captured image.

1 is a block diagram illustrating a configuration of a digital camera according to a first embodiment. FIG. 2 is a block diagram illustrating a configuration of an OIS processing unit in the digital camera according to the first embodiment. FIG. 2 is a block diagram illustrating a configuration of a BIS processing unit in the digital camera according to the first embodiment. Explanatory drawing of the peripheral light amount drop in the digital camera of Embodiment 1 (A) is a principle diagram of a peripheral light amount drop in the digital camera of the first embodiment, and (b) is a characteristic graph of a peripheral light amount drop in the digital camera of the first embodiment. (A) is a characteristic graph of peripheral light amount drop in the digital camera of the first embodiment, (b) is a characteristic graph of peripheral light amount correction gain in the digital camera of the first embodiment, and (c) is a digital camera of the first embodiment. Characteristic graph after peripheral light amount correction in (A) is an explanatory diagram of the principle of peripheral light quantity characteristics when the OIS lens is shifted in the digital camera of the first embodiment, and (b) is a principle of camera shake correction by the OIS lens shift in the digital camera of the first embodiment. (A) is an explanatory diagram of the principle of the peripheral light quantity characteristic at the time of CCD shift in the digital camera of the first embodiment, and (b) is a principle diagram of camera shake correction by CCD shift in the digital camera of the first embodiment. (A) is a peripheral light quantity characteristic graph after the OIS lens shift in the digital camera of the first embodiment, (b) is a characteristic graph of the peripheral light quantity correction gain after the OIS lens shift in the digital camera of the first embodiment, and (c). Fig. 5 is a characteristic graph after correcting the peripheral light amount after the OIS lens shift in the digital camera of the first embodiment. (A) is a peripheral light amount characteristic graph after CCD shift in the digital camera of Embodiment 1, (b) is a characteristic graph of peripheral light amount correction gain after CCD shift in the digital camera of Embodiment 1, and (c) is an implementation. Characteristic graph after peripheral light amount correction after CCD shift in the digital camera of Form 1 FIG. 3 is a block diagram illustrating a configuration of an OIS processing unit in a digital camera according to a second embodiment. FIG. 3 is a block diagram illustrating a configuration of a BIS processing unit in a digital camera according to a second embodiment. 8 is a flowchart showing shake correction processing in the digital camera according to the second embodiment. The figure which shows the change of a shake detection signal, a BIS control signal, and an OIS control signal in the shake correction process of Embodiment 2.

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

  The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims. Hereinafter, a digital camera will be described as an example of the imaging apparatus.

(Embodiment 1)
The digital camera according to the present embodiment includes a shake correction function (function for performing image shake correction) that reduces the influence of camera shake on a captured image in each of the interchangeable lens and the camera body. Hereinafter, the configuration and operation of the camera of the present embodiment will be described in detail.

  In the following description, the function of correcting the blur by shifting the correction lens in the interchangeable lens is referred to as an “OIS (Optical Image Stabilizer) function”. The function of correcting the blur by shifting the image sensor in the camera body is referred to as a “BIS (Body Image Stabilizer) function”. In the digital camera 1 according to the present embodiment, the OIS function can be corrected with higher accuracy than the BIS function.

1. Configuration FIG. 1 is a block diagram showing a configuration of a digital camera according to Embodiment 1 of the present invention. The digital camera 1 includes a camera body 100 and an interchangeable lens 200 that can be attached to and detached from the camera body 100.

1-1. Camera Body The camera body 100 includes a CCD (charge-coupled device) 110, a liquid crystal monitor 120, a camera controller 140, a body mount 150, a power source 160, and a card slot 170.

  The camera controller 140 controls the overall operation of the digital camera 1 by controlling components such as the CCD 110 in accordance with an instruction from the release button 130. The camera controller 140 transmits a vertical synchronization signal to the timing generator (TG) 112. In parallel with this, the camera controller 140 generates an exposure synchronization signal. The camera controller 140 periodically transmits the generated exposure synchronization signal to the lens controller 240 via the body mount 150 and the lens mount 250. The camera controller 140 uses the DRAM 141 as a work memory during control operations and image processing operations.

  The CCD 110 captures a subject image incident through the interchangeable lens 200 and generates image data. The generated image data is digitized by an AD converter (ADC) 111. The digitized image data is subjected to predetermined image processing by the camera controller 140. The predetermined image processing includes, for example, gamma correction processing, white balance correction processing, scratch correction processing, YC conversion processing, electronic zoom processing, and JPEG compression processing.

  The CCD 110 operates at a timing controlled by the timing generator 112. Examples of the operation of the CCD 110 include a still image capturing operation and a through image capturing operation. The through image is mainly a moving image, and is displayed on the liquid crystal monitor 120 in order for the user to determine a composition for capturing a still image.

  The liquid crystal monitor 120 displays an image indicated by the display image data image-processed by the camera controller 140. The liquid crystal monitor 120 can selectively display both moving images and still images.

  The card slot 170 can be loaded with a memory card 171 and controls the memory card 171 based on the control from the camera controller 140. The digital camera 1 can store image data in the memory card 171 and read image data from the memory card 171.

  The power supply 160 supplies power to each element in the digital camera 1.

  The body mount 150 can be mechanically and electrically connected to the lens mount 250 of the interchangeable lens 200. The camera body 100 and the interchangeable lens 200 can transmit and receive data via connectors mounted on the body mount 150 and the lens mount 250. The body mount 150 transmits the exposure synchronization signal received from the camera controller 140 to the lens controller 240 via the lens mount 250. In addition, the body mount 150 transmits other control signals received from the camera controller 140 to the lens controller 240 via the lens mount 250. The body mount 150 transmits a signal received from the lens controller 240 via the lens mount 250 to the camera controller 140. The body mount 150 also supplies power from the power source 160 to the entire interchangeable lens 200 via the lens mount 250.

  Further, the camera body 100 is configured to realize a BIS function (function to correct camera shake by shifting the CCD 110), a gyro sensor 184 that detects camera shake of the camera body 100, and a shake correction process based on the detection result of the gyro sensor 184. And a BIS processing unit 183 for controlling. Furthermore, the camera body 100 includes a CCD drive unit 181 that moves the CCD 110 and a position sensor 182 that detects the position of the CCD 110. The CCD drive unit 181 can be realized by a magnet and a flat coil, for example. The position sensor 182 is a sensor that detects the position of the CCD 110 in a plane perpendicular to the optical axis of the optical system. The position sensor 182 can be realized by a magnet and a Hall element, for example. The BIS processing unit 183 controls the CCD driving unit 181 based on the signal from the gyro sensor 184 and the signal from the position sensor 182 so that the CCD 110 is placed in a plane perpendicular to the optical axis so as to cancel the camera body 100 shake. Shift with.

  Here, the image sensor provided in the camera body 100 is a CCD, but another image sensor such as a CMOS (complementary metal oxide semiconductor) sensor may be used. The CCD driving unit 181 may use other actuators such as a stepping motor and an ultrasonic motor. When a stepping motor is used as the actuator, open control is possible, and accordingly, a position sensor can be dispensed with.

1-2. Interchangeable Lens The interchangeable lens 200 includes an optical system, a lens controller 240, and a lens mount 250. The optical system includes a zoom lens 210, an OIS lens 220, and a focus lens 230. The interchangeable lens 200 includes a DRAM 141 and a flash memory 242.

  The zoom lens 210 is a lens for changing the magnification of a subject image formed by the optical system. The zoom lens 210 is composed of one or a plurality of lenses. The zoom lens driving unit 211 includes a zoom ring or the like that can be operated by the user, transmits the operation by the user to the zoom lens 210, and moves the zoom lens 210 along the optical axis direction of the optical system.

  The focus lens 230 is a lens for changing the focus state of the subject image formed on the CCD 110 by the optical system. The focus lens 230 is composed of one or a plurality of lenses.

  The focus lens driving unit 233 includes a motor, and moves the focus lens 230 along the optical axis of the optical system based on the control of the lens controller 240. The focus lens driving unit 233 can be realized by a DC motor, a stepping motor, a servo motor, an ultrasonic motor, or the like.

  The OIS lens 220 is a lens for correcting blurring of a subject image formed by the optical system of the interchangeable lens 200 in the OIS function (function for correcting camera shake by shifting the OIS lens 220). The OIS lens 220 moves in a direction that cancels out the blur of the digital camera 1, thereby reducing the blur of the subject image on the CCD 110. The OIS lens 220 is composed of one or a plurality of lenses. Under the control of the OIS processing unit 223, the OIS driving unit 221 shifts the OIS lens 220 within a plane perpendicular to the optical axis of the optical system.

  The OIS drive unit 221 can be realized by a magnet and a flat coil, for example. The position sensor 222 is a sensor that detects the position of the OIS lens 220 in a plane perpendicular to the optical axis of the optical system. The position sensor 222 can be realized by a magnet and a Hall element, for example. The OIS processing unit 223 controls the OIS driving unit 221 based on the output of the position sensor 222 and the output of the gyro sensor 224 (blur detector). Here, the OIS driving unit 221 may use other actuators such as an ultrasonic motor.

  The gyro sensor 184 or 224 detects shake (vibration) in the yawing direction and the pitching direction based on an angular change per unit time of the digital camera 1, that is, an angular velocity. The gyro sensor 184 or 224 outputs an angular velocity signal indicating the detected blur amount (angular velocity) to the OIS processing unit 223 or the BIS processing unit 183. The angular velocity signal output by the gyro sensor 184 or 224 may include a wide range of frequency components due to camera shake or mechanical noise. In this embodiment, a gyro sensor is used as the angular velocity detection means, but other sensors can be used as long as they can detect the shake of the digital camera 1 instead of the gyro sensor.

  The camera controller 140 and the lens controller 240 may be configured with a hard-wired electronic circuit or a microcomputer using a program.

1-3. OIS Processing Unit The configuration of the OIS processing unit 223 in the interchangeable lens 200 will be described with reference to FIG. The OIS processing unit 223 includes an ADC (analog / digital conversion) / LPF (low pass filter) 305, an HPF (high pass filter) 306, a phase compensation unit 307, an integrator 308, an LPF 309, An adder 310 and a PID (Proportional-Integral-Derivative) control unit 311 are included.

  The ADC / LPF 305 converts the angular velocity signal from the gyro sensor 224 from an analog format to a digital format. Further, the ADC / LPF 305 blocks high-frequency components of the angular velocity signal converted into the digital format in order to eliminate noise and extract only the blur of the digital camera 1. The frequency of camera shake of the photographer is a low frequency of about 1 to 10 Hz, and the cutoff frequency of the LPF is set in consideration of this point. If noise is not a problem, the LPF function can be omitted.

  The HPF 306 blocks a predetermined low frequency component included in the signal received from the ADC / LPF 305 in order to block the drift component. The phase compensation unit 307 corrects a phase lag caused by the OIS driving unit 221 and lens-body communication (described later) with respect to the signal received from the HPF 306.

  The integrator 308 integrates the signal indicating the angular velocity of vibration (vibration) input from the phase compensation unit 307, and generates a signal indicating the angle of vibration (vibration). Hereinafter, the signal generated by the integrator 308 is referred to as a “blur detection signal”.

  The shake detection signal from the integrator 308 is input to the LPF 309 and the adder 310. The LPF 309 cuts the high frequency component of the blur detection signal and passes the low frequency component (hereinafter referred to as “low frequency blur signal”). The low frequency blur signal is a signal indicating a blur correction amount related to blur in the low frequency region. Here, the cutoff frequency of the LPF 309 is set to, for example, 5 Hz in consideration of the camera shake frequency (1 to 10 Hz). Here, the LPF is used to generate the low-frequency component blur signal. However, any filter may be used as long as it is a filter that cuts high-frequency components such as another filter, for example, LSF (low shelf filter). Further, the filter configuration is not limited to this configuration, and for example, another configuration such as changing the order of the HPF 306 and the integrator 308 may be used.

  The adder 310 subtracts the low-frequency component of the shake detection signal extracted by the LPF 309 from the shake detection signal input from the integrator 308, thereby subtracting the high-frequency component of the shake detection signal (hereinafter referred to as “high-frequency shake signal”). Extract. The high-frequency blur signal is a signal indicating a blur correction amount related to blur in a high-frequency region. The high frequency blur signal is input to the PID control unit 311. On the other hand, the low frequency blur signal is transmitted to the camera body 100.

  The PID control unit 311 performs PID control based on the difference between the input high-frequency blur signal and the current position information of the OIS lens 220 received from the position sensor 222, generates a drive signal for the OIS drive unit 221, and performs OIS drive. Send to part 221. The OIS drive unit 221 drives the OIS lens 220 based on the drive signal.

1-4. BIS Processing Unit The configuration of the BIS processing unit 183 in the camera body 100 will be described with reference to FIG. The BIS processing unit 183 includes an ADC (analog / digital conversion unit) / LPF (low pass filter) 405, an HPF (high pass filter) 406, a phase compensation unit 407, an integrator 408, and a selector 412. And a PID control unit 410.

  The basic functions of the ADC / LPF 405, the HPF 406, the phase compensation unit 407, the integrator 408, and the PID control unit 410 are the same as the functions of the corresponding elements in the OIS processing unit 223.

  The BIS processing unit 183 is based on either one of the output of the gyro sensor 184 provided in the camera body 100 (the output of the integrator 408) and the low-frequency blur signal received from the interchangeable lens 200, in particular. The camera is configured to perform shake correction processing. For this reason, the BIS processing unit 183 selects one of the output of the gyro sensor 184 provided in the camera body 100 (the output of the integrator 408) and the low-frequency blur signal received from the interchangeable lens 200. And a selector 412 that outputs to the PID control unit 410. The selector 412 selects the output of the gyro sensor 184 (the output of the integrator 408) when realizing the shake correction function on the camera body 100 side, such as when the interchangeable lens does not have a shake correction function. The selector 412 is controlled by the camera controller 140.

  The PID control unit 410 generates a driving signal for shifting the CCD 110 based on the output from the position sensor 182 and the output from the integrator 408 or the low frequency blur signal from the interchangeable lens 200 to generate a CCD driving unit. Output to 181. The CCD drive unit 181 drives the CCD 110 based on the drive signal.

2. Operation 2-1. Camera shake correction process The camera shake correction process in the digital camera 1 configured as described above will be described. In the following description, an example in which the OIS lens 220 and the CCD 110 are driven based on a signal from the gyro sensor 224 provided on the lens side of the two gyro sensors 224 and 184 will be described. That is, the digital camera 1 uses a gyro sensor 224 provided on the lens side. At this time, the selector 412 in the BIS processing unit 183 is controlled to select a low frequency blur signal and output it to the PID control unit 410. At this time, the digital camera 1 operates with the interchangeable lens 200 having the gyro sensor 224 to be used as a master and the other camera body 100 as a slave.

  The OIS processing unit 223 receives the detection signal from the gyro sensor 224 and generates a shake detection signal from the received detection signal. Then, the shake detection signal is separated into a high frequency shake signal and a low frequency shake signal. The OIS processing unit 223 generates a drive signal for shifting the OIS lens 220 based on the high-frequency blur signal and the position information from the position sensor 222, and outputs the drive signal to the OIS drive unit 221. The OIS driving unit 221 shifts the OIS lens 220 on a plane perpendicular to the optical axis so as to cancel the high-frequency blur detected by the gyro sensor 224 according to the driving signal from the OIS processing unit 223.

  The low frequency blur signal generated in the OIS processing unit 223 is transmitted to the camera body 100 using communication between the interchangeable lens and the camera body via the lens mount 250 and the body mount 150. At this time, in the BIS processing unit 183 of the camera body 100, the selector 412 is controlled so as to select a low-frequency blur signal from the interchangeable lens 200. The BIS processing unit 183 generates a drive signal for driving the CCD 110 based on the low-frequency blur signal from the interchangeable lens 200 and the position information from the position sensor 182, and transmits the drive signal to the CCD drive unit 181. The CCD drive unit 181 shifts the CCD 110 on a plane perpendicular to the optical axis so as to cancel the low-frequency blur detected by the gyro sensor 224 in accordance with the drive signal from the BIS processing unit 183. Here, the communication between the interchangeable lens and the camera body is performed via the lens mount 250 and the body mount 150, but may be performed by optical communication or wireless communication.

  As described above, the digital camera 1 according to the present embodiment operates the shake correction function on the interchangeable lens 200 side based on the high frequency component in the detected shake signal, and based on the low frequency component in the detected shake signal. The camera shake correction function on the camera body 100 side is activated. As described above, in this embodiment, the camera shake correction function is shared between the camera body 100 and the interchangeable lens 200, so that only the high-frequency shake needs to be corrected on the interchangeable lens 200 side. For this reason, it becomes possible to effectively utilize the correction range of the OIS lens 220 on the interchangeable lens 200 side.

  In the present embodiment, the interchangeable lens 200 side is the master, but the camera body 100 side may be used as the master. That is, the OIS function and the BIS function may be controlled based on the output from the gyro sensor 184 of the camera body 100. In this case, it is preferable that the BIS processing unit 183 has a configuration that separates the shake signal based on the detection signal from the gyro sensor 184 into a low frequency shake signal and a high frequency shake signal as shown in FIG. The low frequency blur signal is transmitted from the camera body 100 to the interchangeable lens 200, and the driving of the OIS lens 220 is controlled on the interchangeable lens 200 side based on the low frequency blur signal. On the other hand, on the camera body 100 side, the drive of the CCD 110 is controlled based on the high-frequency blur signal. In this case, the BIS correction range can be effectively used on the camera body 100 side.

  That is, if one of the interchangeable lens 200 and the camera body 100 used as a master is controlled based on the high-frequency shake signal, the other shake correction function is controlled based on the low-frequency shake signal. Good.

  Here, the reference for selecting the master from the camera body 100 and the interchangeable lens 200 is preferably determined based on the accuracy of blur correction by the OIS function and the BIS function. In the digital camera 1 according to the present embodiment, the OIS function can perform blur correction with higher accuracy than the BIS function, so the interchangeable lens 200 side is used as a master. With this configuration, the two shake correction functions can be efficiently used. The digital camera 1 according to the present embodiment corrects a high-frequency component of a shake detection signal using an OIS function that can be corrected with high accuracy, while detecting a shake using a BIS function that is less accurate than the OIS function. Correct the low-frequency component of the signal. Therefore, the digital camera 1 actively transmits the low frequency component of the shake detection signal from the master.

2-2. As described above, the digital camera 1 according to the present embodiment includes the interchangeable lens 200 and the camera main body 100, and cooperates with the OIS function on the interchangeable lens 200 side and the BIS function of the camera main body 100. By doing so, image blur is corrected. The basic principle of the peripheral light amount correction in the digital camera 1 will be described below.

  FIG. 4 is a diagram for explaining the principle of the decrease in the amount of peripheral light in the digital camera of the present embodiment. The optical system includes a zoom lens 210, an OIS lens 220, and a focus lens 230. The image sensor is composed of a CCD 110. The OIS lens 220 has a function of correcting camera shake by shifting in a direction perpendicular to the optical axis direction. Here, an example in which the OIS lens 220 is held at the center is shown. FIG. 4 shows boundaries L1 and L2 of the light beam range in which the subject image can be captured. The light beam range L1 to L2 for capturing the subject image corresponds to the light beam range L3 to L4 on the CCD 110 side. On the other hand, the boundaries L30 and L40 of the light range captured by the CCD 110 are shown in FIG. The light beam range L30 to L40 picked up by the CCD 110 corresponds to the light beam range L10 to L20 on the subject side (left side of the zoom lens 210). Further, a point A in the figure indicates an intersection between the extended line of the surface of the CCD 110 and the light beam range L3, and a point B in the figure indicates an intersection between the end point of the CCD 110 and the light beam range L30. Details regarding these intersections A and B will be described with reference to FIG.

  In a general optical system, the amount of light that is imaged decreases toward the periphery of the image sensor. Specifically, in FIG. 4, the amount of light gradually decreases from the center of the optical axis indicated by the alternate long and short dash line along the CCD 110 from L30 to L3 in the upper vertical direction, and decreases from the optical axis center indicated by the alternate long and short dash line along the CCD 110. The amount of light gradually decreases from L40 to L4 in the vertical direction.

  FIG. 5A shows a principle diagram of the peripheral light amount decrease, and FIG. 5B shows a characteristic graph of the peripheral light amount decrease. FIG. 5A shows the light amount distribution C of the subject image on the CCD 110 side through the zoom lens 210, the OIS lens 220, and the focus lens 230. Further, an outer shape D of the CCD 110 is shown. The light amount distribution C of the subject image on the CCD 110 side is referred to as an effective image circle, and so-called vignetting occurs in which an appropriate light amount cannot be obtained outside the effective image circle. A point A where the alternate long and short dash line intersects the outer shape of the light quantity distribution C corresponds to the intersection A in FIG. 4 described above. A point B where the alternate long and short dash line intersects the outer shape D of the CCD 110 corresponds to the intersection B in FIG. 4 described above.

  In FIG. 5B, the horizontal axis indicates the image height and corresponds to the coordinates along the alternate long and short dash line in FIG. The vertical axis indicates the peripheral light amount ratio, the center of the light amount distribution C in FIG. 5A is 0, the peripheral light amount ratio is 1.0, and the image height along the alternate long and short dash line in FIG. It shows the characteristic that the peripheral light amount decreases. Here, an image height of 1.0 is defined as a point B where the one-dot chain line in FIG. In addition, an area outside the intersection A (area where the image height exceeds 1.2) shows an area where vignetting occurs and a normal amount of light cannot be obtained, and is cut in the characteristic graph of FIG. In the characteristic graph of the peripheral light amount drop in FIG. 5B, as a specific example, the peripheral light amount ratio when the image height is 1.0 is 0.5, and the peripheral light amount ratio when the image height is 1.2 is 0.1. 35. In addition, the characteristic graph of the peripheral light amount drop with the image height being 0 is a symmetrical shape. The coordinate of the image height from 0 to the left side shows a characteristic graph from -1.2 to the image height of -1.2.

  Next, a specific example in which the peripheral light amount correction is performed will be described with reference to FIG. 6A shows a characteristic graph of peripheral light amount drop, FIG. 6B shows a characteristic graph of peripheral light amount correction gain, and FIG. 6C shows a characteristic graph after peripheral light amount correction. 6A is the same as the characteristic graph of the peripheral light amount drop in FIG. 5B described above, but the graph is limited to the light amount projected on the CCD 110, so the horizontal axis represents the image height. It is limited to -1.0 to 1.0. FIG. 6B shows a characteristic graph of the peripheral light amount correction gain when the peripheral light amount correction is performed in accordance with the peripheral light amount drop characteristic of FIG. In the camera controller 140 in FIG. 1, the peripheral light quantity is corrected by increasing the image data input to the camera controller 140 through the CCD 110 and the ADC 111 according to the image height and the correction gain. In FIG. 6C, the peripheral light amount regardless of the image height is obtained by multiplying the peripheral light amount drop characteristic of FIG. 6A and the peripheral light amount correction gain characteristic of FIG. 6B for each image height. An example in which the ratio can be corrected to 1.0 is shown. In FIG. 6C, a characteristic graph of the peripheral light amount drop of the broken line (same as the characteristic graph of FIG. 6A) becomes a characteristic graph after the peripheral light amount correction of the solid line by the correction.

2-3. Principle of peripheral light amount correction in the image stabilization system The subject image projected on the CCD 110 is shifted around the periphery of the CCD 110 by a shift by a correction lens (hereinafter referred to as an OIS lens) or a shift by an image sensor (hereinafter referred to as a CCD). The amount of light further decreases. Here, a specific embodiment for solving the problem that the quality of an image taken in this way is lowered will be described.

2-3-1. Principle of peripheral light quantity characteristic by OIS lens shift FIG. 7A shows the principle of the peripheral light quantity characteristic at the time of OIS lens shift, and FIG. 7B shows the principle of camera shake correction by the OIS lens shift. In FIG. 7B, only the requirements as the points of explanation are described as the digital camera 1 including the CCD 110 in the camera body 100 and the OIS lens 220 in the interchangeable lens 200. Assuming that the digital camera 1 is rotated about the OIS lens 220 by an angle θ with respect to the optical axis L5 due to camera shake, the optical axis L5 rotates to the optical axis L50 rotated about the OIS lens 220 by an angle θ. In this case, the OIS lens 220 is shifted by the shift amount X1 in accordance with the rotation angle θ of the digital camera 1 due to camera shake so that the rotated optical axis L50 coincides with the optical axis L5 on the right side of the OIS lens 220. Make corrections. Thereby, even when the digital camera 1 rotates due to camera shake, the subject image can be formed on the CCD 110 without blurring. As an example, if the focal length f of the interchangeable lens 200 is 150 mm and the angle θ rotated by camera shake of the digital camera 1 is 0.3 degrees, the optical axis L5 on the CCD 110 is rotated to the optical axis L50 that is rotated, thereby being about 0. The imaging position will be shifted by .78 mm. Therefore, the shift of the imaging position can be corrected by shifting the OIS lens 220. Although the shift amount of the OIS lens 220 in this case depends on the optical design, for example, when the shift amount X1 is set to 0.3 mm, the image forming position is returned by a shift of 0.78 mm, thereby correcting the camera shake. Can be realized.

  In FIG. 7A, the OIS lens 220 has a function of correcting camera shake by shifting in the direction perpendicular to the optical axis direction. First, a case where the OIS lens 220 is held at the center will be described. FIG. 7A shows boundaries L1 and L2 of the light beam range in which a subject image can be captured when the OIS lens 220 is held at the center. The light beam range L1 to L2 for capturing the subject image corresponds to the light beam range L3 to L4 on the CCD 110 side. On the other hand, FIG. 7A shows boundaries L30 and L40 of the light beam range imaged by the CCD 110. FIG. The boundaries L30 to L40 of the light range captured by the CCD 110 correspond to the light ranges L10 to L20 on the subject side (left side of the zoom lens 210). Here, as described with reference to FIG. 7B, when the digital camera 1 is rotated by the angle θ around the OIS lens 220 due to camera shake, the amount of shift of the OIS lens 220 in the direction perpendicular to the optical axis is shifted. By shifting by X1, it is possible to correct the shift of the imaging position of the subject image on the CCD 110 due to camera shake. At this time, the light range L10 to L20 on the subject side (left side of the zoom lens 210) corresponding to the light range L30 to L40 projected onto the CCD 110 moves from the light range L100 to L200. In this way, when the light ray range on the subject side is moved by the camera shake correction by the shift of the OIS lens 220, the light ray range boundary L20 moves to the light ray range boundary L200, and the light ray range boundary L2 that can capture the subject. , The light amount of the light beam L30 corresponding to the CCD 110 side slightly decreases. On the other hand, the distance L10 of the light beam range moves to the boundary L100 of the light beam range and moves away from the boundary L1 of the light beam range where the subject can be captured, so that the light amount of the light beam L40 corresponding to the CCD 110 side slightly increases.

2-3-2. Principle of peripheral light quantity characteristic by CCD shift FIG. 8A shows a principle explanatory view of peripheral light quantity characteristic at the time of CCD shift, and FIG. 8B shows a principle of camera shake correction by CCD shift. In FIG. 8B, only the requirements that are the points of explanation are described as the digital camera 1 including the CCD 110 in the camera body 100 and the OIS lens 220 in the interchangeable lens 200. Assuming that the digital camera 1 is rotated about the OIS lens 220 about the optical axis L5 by camera shake, the angle θ is rotated about the OIS lens 220 up to the optical axis L50 where the optical axis L5 is rotated. In this case, the CCD 110 is shifted by X2 according to the rotation angle θ of the digital camera 1 due to camera shake, so that the intersection coordinates on the CCD 110 by the optical axis L5 are corrected to coincide with the intersection coordinates on the CCD 110 by the optical axis L50. I do. Thereby, even when the digital camera 1 rotates due to camera shake, the subject image can be formed on the CCD 110 without blurring. As an example, assuming that the focal length f of the interchangeable lens 200 is 150 mm and the rotation angle θ due to camera shake of the digital camera 1 is 0.3 degrees, the optical axis L5 rotates to the optical axis L50 on the CCD 110 and is about 0.78 mm. The imaging position will shift. Therefore, the shift of the imaging position can be corrected by shifting the CCD 110 by about 0.78 mm.

  In FIG. 8A, the CCD 110 has a function of correcting camera shake by shifting in the direction perpendicular to the optical axis direction. First, a case where the CCD 110 is held at the center will be described. FIG. 8A shows boundaries L1 and L2 of a light beam range in which a subject image can be captured when the CCD 110 is held at the center. The light beam range L1 to L2 for capturing the subject image corresponds to the light beam range L3 to L4 on the CCD 110 side. On the other hand, FIG. 8A shows boundaries L30 and L40 of the light beam range imaged by the CCD 110. FIG. The light beam range L30 to L40 picked up by the CCD 110 corresponds to the light beam range L10 to L20 on the subject side (left side of the zoom lens 210).

  Here, as described with reference to FIG. 8B, when the digital camera 1 is rotated by the angle θ about the OIS lens 220 due to camera shake, the CCD 110 is shifted by the shift amount X2 in the direction perpendicular to the optical axis. By shifting, it is possible to correct a shift in the imaging position of the subject image on the CCD 110 due to camera shake. Before the CCD 110 shift, the light beam ranges L30 to L40 projected onto the CCD 110 correspond to the light beam ranges L10 to L20 on the subject side (left side of the zoom lens 210). After the shift amount X2 of the CCD 110 is shifted, the light range L300 to L400 projected onto the CCD 110 corresponds to the light range L100 to L200 on the subject side (left side of the zoom lens 210). The light beam range L100 to L200 is the same as that at the time of camera shake correction by the shift of the OIS lens 220 described above. That is, when the rotation angle due to camera shake of the digital camera 1 is θ, the angle of view to be captured on the subject side is the same.

  Similarly, in the light ray range on the subject side (the left side of the zoom lens 210), the light ray range boundary L10 moves to the boundary L100, so that it is far from L1, which is the light ray range boundary where the subject can be captured. The amount of light that the L100 light beam is projected onto the CCD 110 side slightly increases. On the other hand, in the light ray range on the subject side (the left side of the zoom lens 210), the light ray boundary L20 moves to the boundary L200, and approaches the light ray range boundary L2 where the subject can be captured. However, the amount of light projected on the CCD 110 side is slightly reduced. In addition, after the shift amount X2 of the CCD 110 is shifted, the boundary L300 of the light beam range projected onto the CCD 110 approaches the light beam boundary L3 corresponding to the outer shape of the effective image circle, so that the amount of light due to the light beam at the boundary L300 projected onto the CCD 110. Is further reduced. That is, in addition to a decrease in the amount of light incident on the interchangeable lens 200 due to the light ray boundary L200, the light amount further decreases due to a decrease in the light amount at the light ray boundary L300 corresponding to the light ray boundary L200. On the other hand, after the shift amount X2 of the CCD 110 is shifted, the boundary L400 of the light beam range projected onto the CCD 110 is far from the light beam boundary L4 corresponding to the outer shape of the effective image circle. Increases further. That is, in addition to the increase in the amount of light incident on the interchangeable lens 200 due to the light ray boundary L100, the light amount further increases due to the increase in the light amount at the light ray boundary L400 corresponding to the light ray boundary L100.

  Therefore, in the region where the peripheral light amount decreases due to the shift of the OIS lens or the CCD due to camera shake correction, the peripheral light amount decreases more during the CCD shift than during the OIS lens shift. On the other hand, in the region where the peripheral light amount increases due to the shift of the OIS lens or CCD due to camera shake correction, the peripheral light amount increases more during the CCD shift than during the OIS lens shift.

2-3-3. Method for correcting peripheral light quantity characteristic by OIS lens shift A specific example of correcting a change in peripheral light quantity characteristic caused by the OIS lens shift will be described with reference to FIG. FIG. 9A shows a peripheral light quantity characteristic graph after the OIS lens shift, FIG. 9B shows a peripheral light quantity correction gain characteristic graph (after the OIS lens shift), and FIG. 9C shows the peripheral light quantity correction. The characteristic graph (after OIS lens shift) is shown.

  In FIG. 9A, the image height at the center on the CCD 110 is set to 0, the image heights at the corners on the CCD 110 are represented by −1.0 and 1.0, and the peripheral light amount ratio corresponding to the image height is represented. . The broken line graph is a graph showing the characteristics of the peripheral light amount before the OIS lens shift. The solid line graph is a graph showing the characteristics of the peripheral light quantity after the OIS lens is shifted, that is, in the state where the shift amount is shifted by the shift amount X1 in the direction perpendicular to the optical axis. As described above, this graph shows that the OIS lens shift slightly reduces the peripheral light amount before the OIS lens shift when the image height is 1.0, and the OIS lens shift when the image height is −1.0. It shows a slight increase from the previous peripheral light amount.

  FIG. 9B shows a characteristic graph of the peripheral light amount correction gain when the peripheral light amount correction is performed in accordance with the peripheral light amount drop characteristic of FIG. Here, an example is shown in which the peripheral light amount correction after the OIS lens shift is performed, and thus corresponds to the graph indicated by the solid line in FIG. In the camera controller 140 in FIG. 1, the peripheral light quantity is corrected by increasing the image data input to the camera controller 140 through the CCD 110 and the ADC 111 according to the image height and the correction gain. In FIG. 9C, by multiplying the peripheral light amount drop characteristic shown by the solid line in FIG. 9A and the peripheral light amount correction gain characteristic in FIG. 9B for each image height, the image height is related. An example in which the peripheral light amount ratio can be corrected to 1.0 is shown. In FIG. 9C, the characteristic graph of the peripheral light amount drop indicated by the broken line (same as the characteristic graph indicated by the solid line in FIG. 9A) becomes a characteristic graph after the peripheral light amount correction by the solid line.

  In FIG. 9B, a gain at an image height of 1.0 is defined as G1, a gain at an image height of -1.0 is defined as G2, and a peripheral light quantity characteristic correction method by CCD shift described later is used. The gains G1 and G2 are used in the description.

2-3-4. Method for correcting peripheral light quantity characteristic by CCD shift A specific example of correcting a change in peripheral light quantity characteristic caused by CCD shift will be described with reference to FIG. 10A shows a peripheral light quantity characteristic graph after the CCD shift, FIG. 10B shows a peripheral light quantity correction gain characteristic graph (after the CCD shift), and FIG. 10C shows the characteristic after the peripheral light quantity correction. A graph (after CCD shift) is shown.

  In FIG. 10A, the image height at the center on the CCD 110 is set to 0, the image heights at the corners on the CCD 110 are represented by −1.0 and 1.0, and the peripheral light amount ratio corresponding to the image height is represented. . The broken line graph is a graph showing the characteristics of the peripheral light amount before the CCD shift. The solid line graph is a graph showing the characteristics of the peripheral light amount after the CCD shift, that is, in a state in which it is shifted by X2 in the direction perpendicular to the optical axis. As described above, this graph shows a state in which the CCD light shift reduces the peripheral light amount before the CCD shift when the image height is 1.0, and the peripheral light amount before the CCD shift when the image height is −1.0. It shows a slight increase. In particular, when FIG. 10A is compared with FIG. 9A, when the image height is 1.0, the amount after the CCD shift is after the OIS lens shift with respect to the peripheral light amount before the CCD shift or before the OIS lens shift. It shows a state in which the peripheral light amount is greatly decreased. Further, comparing FIG. 10A and FIG. 9A, when the image height is −1.0, the OIS lens shift is after the CCD shift with respect to the peripheral light amount before the CCD shift or before the OIS lens shift. It shows a situation in which the peripheral light amount increases more than later.

  FIG. 10B shows a characteristic graph of the peripheral light amount correction gain when the peripheral light amount correction is performed in accordance with the peripheral light amount drop characteristic of FIG. FIG. 10B shows an example in which the peripheral light amount correction after the CCD shift is performed, and therefore corresponds to the graph shown by the solid line in FIG. In the camera controller 140 in FIG. 1, the peripheral light quantity is corrected by increasing the image data input to the camera controller 140 through the CCD 110 and the ADC 111 according to the image height and the correction gain. In FIG. 10C, the peripheral light amount drop characteristic shown by the solid line in FIG. 10A is multiplied by the peripheral light amount correction gain characteristic in FIG. An example in which the peripheral light amount ratio can be corrected to 1.0 is shown. In FIG. 10C, the characteristic graph of the peripheral light amount drop indicated by the broken line (same as the characteristic graph indicated by the solid line in FIG. 10A) becomes the characteristic graph after the peripheral light amount correction by the solid line.

  In FIG. 10B, the gain when the image height is 1.0 is defined as G3, and the gain when the image height is −1.0 is defined as G4. The magnitude relationship between the gains G1 and G2 defined in the description of the correction method of the peripheral light quantity characteristic by the OIS lens shift and the gains G3 and G4 defined in FIG. 10B will be compared. When the image height is 1.0, the relationship is G3> G1, and when the image height is -1.0, the relationship is G4 <G2. That is, with respect to the same camera shake rotation amount θ of the digital camera 1, the peripheral light amount correction gain is increased as the peripheral light amount correction gain is larger after the CCD shift than the OIS lens shift when the image height is 1.0. The CCD shift is set larger than the OIS lens shift. On the other hand, with respect to the same camera shake rotation angle θ of the digital camera 1, the peripheral light amount correction gain becomes smaller after the CCD shift than the OIS lens shift when the image height is −1.0. Is set smaller during CCD shift than during OIS lens shift.

3. Summary In the present embodiment, the decrease in the peripheral light amount at one corner of the CCD and the decrease in the peripheral light amount at the other corner of the CCD are appropriately corrected to prevent a deterioration in the quality of the captured image and to obtain a good captured image. Specific examples that can be provided are given.

  The present embodiment relates to a digital camera 1 that performs camera shake correction by shifting an OIS lens 220 and a CCD 110 in order to reduce the influence of camera shake on a captured image during shooting. In the digital camera 1, the peripheral light amount on the CCD 110 is lowered by shifting the OIS lens 220 with respect to a certain amount of camera shake as compared with the case where camera shake correction is not performed. Further, the peripheral light amount on the CCD 110 is more greatly reduced by shifting the CCD 110 than when the OIS lens 220 is shifted with respect to the same amount of camera shake. Therefore, in this case, the peripheral light amount correction caused by the CCD shift is made larger than the peripheral light amount correction caused by the OIS lens shift, thereby eliminating image quality deterioration due to camera shake or a decrease in the peripheral light amount in the photographed image. can do.

  On the other hand, by shifting the OIS lens 220 with respect to a certain amount of camera shake, the peripheral light amount on the CCD 110 may increase as compared with the case where camera shake correction is not performed, but by shifting the CCD 110 with respect to the same amount of camera shake. However, the peripheral light amount on the CCD 110 increases more greatly. Therefore, in this case, the peripheral light amount correction caused by the CCD shift is made smaller than the peripheral light amount correction caused by the OIS lens shift, thereby eliminating image quality degradation due to camera shake in the photographed image or a drop in the peripheral light amount. can do.

  In particular, by combining both of these, it is possible to reduce the left and right heads of the peripheral light amount drop in the captured image, and to provide a higher quality image.

  That is, the digital camera 1 corrects the amount of peripheral light when a certain amount of camera shake is switched from correction using an OIS lens shift to correction using a CCD shift, or when switching from correction using a CCD shift to correction using an OIS lens shift. Change the amount. As a result, it is possible to eliminate degradation in image quality due to camera shake in the captured image and a decrease in the amount of peripheral light.

(Embodiment 2)
1. Configuration Another configuration example of a digital camera that realizes blur correction will be described. The configuration of the digital camera of the present embodiment is the same as that of the first embodiment except for the OIS processing unit and the BIS processing unit.

  FIG. 11 is a diagram illustrating a configuration of the OIS processing unit 223 in the digital camera 1 according to the present embodiment. The OIS processing unit 223 of the present embodiment includes an ADC / LPF 305, an HPF 306, a phase compensation unit 307, an integrator 308, and a PID control unit 311. The functions of these components are the same as those shown in the first embodiment. The OIS processing unit 223 according to the present embodiment further includes a position shift unit 312 that shifts the center position of the movement of the OIS lens 220 in accordance with an instruction from the lens controller 240. That is, the position shift unit 312 reflects the center position of the movement of the OIS lens 220 in the output (blur detection signal) from the integrator 308. Hereinafter, a signal output from the position shift unit 312 is referred to as an “OIS control signal”.

  FIG. 12 is a diagram illustrating a configuration of the BIS processing unit 183 in the digital camera 1 of the present embodiment. The BIS processing unit 183 according to the present embodiment includes an ADC / LPF 405, an HPF 406, a phase compensation unit 407, an integrator 408, and a PID control unit 410. The functions of these components are the same as those shown in the first embodiment. The BIS processing unit 183 of this embodiment further includes a position setting unit 413 and a selector 414. The position setting unit 413 outputs a signal for setting the position of the CCD 110. The selector 414 selects either the output of the PID control unit 410 or the output of the position setting unit 413 and outputs it to the CCD driving unit 181. The position setting unit 413 and the selector 414 are controlled by the camera controller 140. Hereinafter, the output of the position setting unit 413 is referred to as a “BIS control signal”.

  In the present embodiment, only the OIS function on the interchangeable lens 200 side is used to perform blur correction. For this reason, the selector 414 of the BIS processing unit 183 selects the output of the position setting unit 413. Note that the selector 414 selects the output of the PID control unit 410 when realizing the shake correction function on the camera body 100 side, such as when the interchangeable lens does not have the shake correction function.

2. Operation 2-1. Blur correction process In the blur correction process of the present embodiment, in particular, the OIS lens 220 is centered (shifted to the center position) at the start of the exposure period to perform blur correction during the exposure period. By centering the OIS lens 220, the correction range by the OIS lens 220 during the exposure period can be effectively utilized.

  FIG. 13 is a flowchart showing a shake correction process in the digital camera 1 of the present embodiment. As described above, the digital camera 1 operates only the OIS function in a state where exposure is not performed (live view display state) (S11). When the release button 130 is pressed by the user (YES in S12), the camera controller 140 sends a release signal indicating that the release button 130 has been pressed to the lens controller 240 via the body mount 150 and the lens mount 250. Send. Upon receiving the release signal, the lens controller 240 stores information indicating the current position of the OIS lens 220 in the DRAM 241 and controls the OIS processing unit 223 so as to center the position of the OIS lens 220 (move to the center position) ( S13). At this time, the position shift unit 312 generates an OIS control signal that shifts the center position of the movement of the OIS lens 220. Further, the lens controller 240 transmits the position information of the OIS lens 220 stored in the DRAM 241 to the camera body 100 via the lens mount 250 and the body mount 150 (S14).

  Upon receiving the position information of the OIS lens 220 from the interchangeable lens 200, the camera controller 140 of the camera body 100 converts the movement information of the CCD 110 based on the received position information (that is, the position of the OIS lens 220 immediately before centering). The target movement position of the CCD 110 is obtained. The camera controller 140 controls the BIS processing unit 183 to move the CCD 110 to the target movement position (S15). At this time, the position setting unit 413 generates a BIS control signal for moving the CCD 110 to the target movement position. Thereafter, during exposure, the BIS processing unit 183 holds the position of the CCD 110 at the moved position (S16).

  When the exposure ends, the camera controller 140 notifies the lens controller 240 of the end of exposure. The lens controller 240 reads the position information of the OIS lens 220 stored in the DRAM 241 and controls the OIS processing unit 223 to move the OIS lens 220 to the position indicated by the position information (S17). At this time, the position setting unit 413 generates a BIS control signal for moving the CCD 110 to the position indicated by the position information. Further, the BIS processing unit 183 returns the CCD 110 to a predetermined center position with respect to the CCD 110 (S18). At this time, the position setting unit 413 generates a BIS control signal for moving the CCD 110 to a predetermined center position.

  FIG. 14 shows changes in the shake detection signal (output of the integrator 308), the OIS control signal (output of the position shift unit 312), and the BIS control signal (output of the position setting unit 413) in the shake correction processing as described above. It is the figure which showed the example. As shown in the figure, during the exposure period, the OIS lens 220 is controlled to be shifted to the center position and driven around the center position. On the other hand, the CCD 110 is shifted and fixed to a position corresponding to the position of the OIS lens 220 immediately before centering. During a period other than the exposure period, the OIS lens 220 is controlled to be driven around the original center position, and the CCD 110 is also fixed at the original center position.

  As described above, the digital camera 1 according to the present embodiment centers the OIS lens 220 at the start of the exposure period, and shifts the position of the CCD 110 by an amount corresponding to the movement amount of the centering of the OIS lens 220. Then, during the exposure period, the OIS function is executed with the position of the CCD 110 fixed at that position. When the exposure is completed, the position of the OIS lens 220 is returned to the position immediately before the centering, and the CCD 110 is returned to the predetermined center position.

  Thus, by centering the OIS lens 220 at the start of exposure, the correction range by the OIS lens 220 during exposure can be effectively utilized. Further, by compensating the centering of the OIS lens 220 by the movement of the CCD 110, it is possible to prevent the angle of view from shifting due to the centering. As a result, the user can take an image with the same angle of view as that confirmed before exposure, and the digital camera 1 can effectively use image blur correction.

2-2. Peripheral light amount correction in the camera shake correction system The peripheral light amount correction described in the first embodiment is applied to the digital camera 1 of the present embodiment. In the example of FIG. 14 described in the present embodiment, the OIS lens 220 is shifted to the center in order to adjust the angle of view at the timing T0 and enhance the camera shake correction effect. At the same time, the shift of the angle of view that occurs when the OIS lens 220 is shifted to the center is corrected by shifting the CCD 110. Here, assuming that the amplitude corresponding to the camera shake angle of the OIS lens 220 is A1 immediately before T0, the amplitude corresponding to the camera shake angle of the CCD 110 is the same A1 immediately after T0. In this case, the correction of the peripheral light amount caused by the shift of the OIS lens 220 immediately before T0 and the correction of the peripheral light amount caused by the shift of the CCD 110 immediately after T0 are similarly corrected by the method described in the first embodiment. To do. In other words, the camera controller 140 sets the peripheral light amount correction gain to be large before and after T0 because the decrease in the peripheral light amount is larger in the CCD shift than in the OIS lens shift when the image height is 1.0. On the other hand, the camera controller 140 sets the peripheral light amount correction gain to be small because the decrease in the peripheral light amount is smaller after the CCD shift than after the OIS lens shift when the image height is −1.0.

3. Summary In the present embodiment, the digital camera 1 shifts the OIS lens 220 to the center in order to adjust the angle of view at the timing T0 and to improve the camera shake correction effect. At the same time, the shift of the angle of view that occurs when the OIS lens 220 is shifted to the center is corrected by shifting the CCD 110. In this case, by changing the correction amount of the peripheral light amount generated by the shift of the OIS lens 220 immediately before T0 and the correction amount of the peripheral light amount generated by the shift of the CCD 110 immediately after T0, the change immediately before and immediately after T0. Image quality can be ensured.

(Other embodiments)
The idea of the above embodiment is not limited to the embodiment described above. Various embodiments may be envisaged. Hereinafter, other embodiments to which the idea of the above embodiments can be applied will be described.

  In Embodiments 1 and 2, the example using the interchangeable lens and the camera body has been described, but a lens-integrated camera may be used.

  In the first and second embodiments, the above-described functions can be obtained by cooperating software and hardware such as an imaging device and smartphone by loading the software from a storage medium into the imaging device and smartphone as a computer. It may be realized by movement. In addition, a program that achieves the above-described functions may be realized by downloading from a server to an imaging device, a smartphone, or the like and installing it. Furthermore, the functions described above may be realized by mounting a control unit using an electronic circuit such as a semiconductor integrated circuit.

  The embodiment has been described above as an example of the technique in the present disclosure. For this purpose, the detailed description and the accompanying drawings have been disclosed. Therefore, the constituent elements described in the detailed description and the accompanying drawings may include constituent elements that are not essential for solving the problem. Accordingly, just because those non-essential components are described in the detailed description and the accompanying drawings, those non-essential components should not be immediately recognized as essential.

  The above embodiment is for illustrating the technique in the present disclosure. Therefore, various changes, substitutions, additions and / or omissions may be made to the above-described embodiments within the scope of the claims or an equivalent scope thereof.

  The idea of the present disclosure can be applied to an electronic device (an imaging device such as a digital camera or a camcorder, a mobile phone, a smartphone, or the like) having a camera shake correction function.

1 Digital Camera 100 Camera Body 110 CCD
140 camera controller 150 body mount 184,224 gyro sensor 181 CCD drive unit 182,222 position sensor 183 BIS processing unit 200 interchangeable lens 220 OIS lens 221 OIS drive unit 223 OIS processing unit 240 lens controller 250 lens mount

Claims (7)

An optical system composed of a plurality of lenses including a correction lens for correcting image blur;
A lens driving unit that performs image blur correction by moving the correction lens in a plane perpendicular to the optical axis;
An image sensor that captures a subject image formed by the optical system;
An element driving unit that performs image blur correction by moving the imaging element in a plane perpendicular to the optical axis;
A controller that corrects an image captured by the image sensor,
The control unit changes an amount of correction of a peripheral light amount of an image captured by the image sensor when switching between image blur correction by the lens driving unit and image blur correction by the element driving unit. .   The control unit increases a correction amount of the peripheral light amount at one end of the imaging element when switching between image blur correction by the lens driving unit and image blur correction by the element driving unit, and The imaging apparatus according to claim 1, wherein a correction amount of a peripheral light amount at the other end facing the one end is reduced. An optical system composed of a plurality of lenses including a correction lens for correcting image blur;
A lens driving unit that performs image blur correction by moving the correction lens in a plane perpendicular to the optical axis;
An image sensor that captures a subject image formed by the optical system;
An element driving unit that performs image blur correction by moving the imaging element in a plane perpendicular to the optical axis;
A control unit that corrects an image captured by the image sensor;
A display unit for displaying an image corrected by the control unit,
The said control part is an imaging device which changes the correction amount of the peripheral light quantity of the image imaged with the said image pick-up element before and after the exposure start from the live monitor.   The control unit increases the correction amount of the peripheral light amount at one end of the image sensor and decreases the correction amount of the peripheral light amount at the other end facing the one end of the image sensor before and after the start of exposure from the live monitor. Item 4. The imaging device according to Item 3. An interchangeable lens including the optical system and the lens driving unit;
A camera body including the imaging element, the element driving unit, and the control unit;
The imaging apparatus according to claim 1, wherein the interchangeable lens and the camera body are detachable. An imaging step of imaging a subject image formed by an optical system including a correction lens with an imaging element;
A first image blur correction step of correcting image blur by moving the correction lens in a plane perpendicular to the optical axis;
A second image blur correction step of correcting image blur by moving the image sensor in a plane perpendicular to the optical axis;
An image correction step of correcting an image captured by the image sensor,
The image correction step changes a correction amount of the peripheral light amount of the image when the image blur correction by the first image blur correction step and the image blur correction by the second image blur correction step are switched to each other. Imaging method. On the computer,
An imaging step of imaging a subject image formed by an optical system including a correction lens with an imaging element;
A first image blur correction step of correcting image blur by moving the correction lens in a plane perpendicular to the optical axis;
A second image blur correction step of correcting image blur by moving the image sensor in a plane perpendicular to the optical axis;
An image correction step for correcting an image captured by the image sensor, and an imaging program for executing the image correction step,
The image correction step changes a correction amount of the peripheral light amount of the image when the image blur correction by the first image blur correction step and the image blur correction by the second image blur correction step are switched to each other. Imaging program.