Imaging apparatus and method for controlling the same

Abstract

To reduce image shake caused by shutter shake.SOLUTION: An imaging apparatus 101 has: an image pickup element 206 that picks up a subject image formed by an imaging optical system 200; a main body that holds the imaging optical system and holds the image pickup element in a movable manner; first vibration-proofing means IIS that moves the image pickup element relative to the main body; and a mechanical shutter 205 that is fixed to the main body and controls exposure of the image pickup element. Control means 229 controls the first vibration-proofing means to reduce image shake caused by first shake detected irrespective of the drive of the mechanical shutter, and when the drive of the mechanical shutter causes second shake in the main body in the case that the imaging optical system satisfies a predetermined condition, controls the first vibration-proofing means to reduce the relative displacement between the main body and the image pickup element caused by the second shake.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an imaging device having an anti-shake function. [Background technology]

[0002] Methods for correcting (reducing) image blur caused by camera shake include optical image stabilization (hereinafter referred to as OIS), which moves a correction lens, which is at least a part of the imaging optical system, along the optical axis in response to camera shake, and sensor image stabilization (hereinafter referred to as IIS), which moves the imaging element along the optical axis. OIS and IIS may be controlled independently or may be controlled cooperatively at a certain ratio.

[0003] On the other hand, some imaging devices are equipped with a mechanical shutter such as a focal plane shutter, and vibrations (hereinafter referred to as shutter shake) occur in the imaging device due to the actuation of the shutter when capturing a still image. Shutter shake has a frequency that is significantly higher than the responsive frequency of actuators such as voice coil motors that drive the correction lens and imaging element for image stabilization, and is a vibration that lasts for a shorter period of time than camera shake. Therefore, even if the main body of the imaging device or parts of the imaging optical system other than the correction lens shake due to shutter shake, the correction lens and imaging element hardly shake at all. As a result, image shake occurs.

[0004] Patent Document 1 discloses a camera system that acquires shutter shake data and adds a shake compensation amount for shutter vibration to a shake compensation amount for hand shake at the timing when the shutter shake starts in order to correct image shake caused by shutter shake. Patent Document 2 discloses a camera system that uses both an OIS and an IIS to correct image shake caused by shutter shake when the image shake caused by shutter shake cannot be completely corrected by either the OIS or the IIS. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3342251 [Patent Document 2] JP 2021-113836 A Summary of the Invention [Problem to be solved by the invention]

[0006] Figures 2(a) and (b) show a camera system that uses both OIS and IIS. In OIS, the drive direction for correcting image blur differs depending on the sign of the parallel decentering sensitivity, which is an optical characteristic of the correction lens (hereinafter referred to as the optical characteristic of OIS). The parallel decentering sensitivity indicates the weighting amount for suppressing the amount of movement of the subject image on the image sensor caused by camera shake, etc., and has a positive or negative value depending on the direction of suppression.

[0007] Figure 2(a) shows a case where the parallel decentering sensitivity of the OIS is a positive value. In this case, when the body of the imaging device shakes upward due to shutter shake, the subject image (face image) on the imaging element moves upward because the correction lens does not shake, and the subject image on the imaging element moves downward because the imaging element does not shake. As a result of these subject images moving in opposite directions, image blur is reduced.

[0008] On the other hand, Figure 2(b) shows a case where the parallel decentering sensitivity of the OIS is a negative value. In this case, the main body of the imaging device shakes upward, but the correction lens does not shake, so the subject image on the imaging element moves downward, and because the imaging element does not shake, the subject image on the imaging element also moves downward. As a result of these subject images moving to the same side, image blur increases.

[0009] The parallel decentering sensitivity of the OIS is a value specific to each imaging optical system (interchangeable lens, etc.), and is a value that is unrelated to the drive of the mechanical shutter in the imaging device. In contrast, the direction of shutter shake in the main body of the imaging device remains unchanged even if the imaging optical system is changed. For this reason, when using an imaging optical system in which the parallel decentering sensitivity of the OIS is a positive value, in other words, when image shake due to shutter shake is reduced, adding a shutter shake correction value to the hand shake correction value of the IIS will actually increase image shake.

[0010] Furthermore, regardless of the presence or absence of an OIS, shutter vibration propagates from the main body of the image capture device to the imaging optical system. When the imaging optical system is a zoom lens that expands and contracts in response to changes in focal length, image vibration caused by shutter vibration can be reduced by driving the IIS on the wide-angle side where the overall length is short, but image vibration caused by shutter vibration may not be reduced on the telephoto side where the overall length is long.

[0011] The present invention provides an imaging apparatus capable of reducing image blur caused by shutter shake. [Means for solving the problem]

[0012] An imaging device according to one aspect of the present invention includes an imaging element that captures an image of a subject formed by an imaging optical system, a main body that holds the imaging optical system and movably holds the imaging element, a first vibration isolation means that moves the imaging element relative to the main body, a mechanical shutter that is fixed to the main body and controls exposure to the imaging element, and a control means that controls a first drive means. The control means controls the first vibration isolation means to reduce image blur caused by a first shake that is detected regardless of drive of the mechanical shutter, and controls the first vibration isolation means to reduce relative displacement between the main body and the imaging element caused by the second shake when a second shake occurs in the main body due to drive of the mechanical shutter when the imaging optical system satisfies a predetermined condition.

[0013] A control method according to another aspect of the present invention is applied to an imaging device having an imaging element for capturing an image of a subject formed by an imaging optical system, a main body for holding the imaging optical system and movably holding the imaging element, a first vibration isolation means for moving the imaging element relative to the main body, and a mechanical shutter fixed to the main body for controlling exposure of the imaging element. The control method is characterized in that the first vibration isolation means is controlled to reduce image blur caused by a first shake detected regardless of whether the mechanical shutter is driven, and when a second shake occurs in the main body due to the driving of the mechanical shutter when the imaging optical system satisfies a predetermined condition, the first vibration isolation means is controlled to reduce a relative displacement between the main body and the imaging element caused by the second shake. Note that a program for causing a computer of the imaging device to execute processing according to the control method also constitutes another aspect of the present invention. Effect of the Invention

[0014] According to the present invention, it is possible to reduce image blur caused by shutter shake. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a schematic diagram showing an anti-shake mechanism of the digital camera system according to the embodiment. [Diagram 2] 4A and 4B are diagrams for explaining positive and negative parallel decentering sensitivity of an OIS. [Diagram 3] FIG. 1 is a block diagram showing a configuration of a digital camera system. [Figure 4] FIG. 2 is a block diagram showing the configuration of an OIS and IIS control system. [Diagram 5] 13 is a diagram showing a shake correction waveform when camera shake correction and shutter shake correction are performed simultaneously. [Figure 6] FIG. 1 is a diagram explaining OIS / IIS cooperative control and IIS independent control. [Figure 7] 5A and 5B are diagrams for explaining a correction ratio in OIS / IIS emphasis control. [Figure 8] FIG. 13 is a diagram for explaining cutoff sensitivity of filter processing. [Figure 9]4 is a diagram showing a driving range for camera shake correction and a driving range for shutter shake correction of the IIS. [Figure 10] FIG. 11 is a graph showing the amount of OIS and IIS shutter shake correction according to the focal length. [Figure 11] FIG. 13 is a diagram showing an IIS correction amount in a static state. [Figure 12] 4 is a flowchart showing an IIS control process according to the first embodiment. [Figure 13] 5 is a flowchart showing a shutter shake correction determination process according to the first embodiment. [Figure 14] 10 is a flowchart showing another shutter shake correction determination process in the first embodiment. [Figure 15] 5A to 5C are diagrams showing examples of shutter shake correction amounts in the first embodiment. [Figure 16] 10 is a flowchart showing a shutter shake correction determination process according to the second embodiment. [Figure 17] 11 is a flowchart showing a shutter shake correction determination process according to the third embodiment. [Figure 18] 13 is a flowchart showing an IIS control process according to the fourth embodiment. [Figure 19] 13 is a flowchart showing a calculation process of an OIS driving range and a correction ratio according to the fourth embodiment. [Figure 20] 13 is a flowchart showing a filter process according to the fourth embodiment. [Figure 21] 13 is a flowchart showing a shutter shake correction selection process according to a focal length in the fourth embodiment. [Figure 22] 13 is a flowchart showing a shutter shake compensation amount change process according to the fourth embodiment. [Figure 23] 13 is a flowchart showing a shutter shake correction selection process according to a static state in the fifth embodiment. [Figure 24] 13 is a flowchart showing a shutter shake correction amount acquisition process according to the fifth embodiment. [Diagram 25] 20 is a flowchart showing a sensor lock process according to the sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0017] 1 shows a schematic configuration of a lens-interchangeable digital camera system according to an embodiment of the present invention. The lens-interchangeable digital camera system is composed of a digital camera (hereinafter simply referred to as camera) 101 as an imaging device, and an interchangeable lens 110 as a lens device that is detachably attached (connected) to the camera 101. A main body such as a chassis of the camera 101 (hereinafter referred to as camera body) holds an interchangeable lens (imaging optical system) via a mount fixed thereto. The camera 101 has a first vibration isolation means that performs sensor vibration isolation (IIS), and the interchangeable lens 110 has a second vibration isolation means that performs optical vibration isolation (OIS).

[0018] In this embodiment, a lens-interchangeable digital camera system will be described, but other embodiments include various imaging devices such as an integrated lens digital camera.

[0019] 3 shows the electrical and optical configuration of the digital camera system. The interchangeable lens 110 has an imaging optical system 200 including a zoom lens 201, a correction lens (correction optical system) 202 for OIS, a focus lens 203, and an aperture 204. The zoom lens 201 moves in the optical axis direction of the imaging optical system 200 to change the focal length (angle of view) of the imaging optical system 200. The correction lens 202 moves in a direction perpendicular to the optical axis (or may be a direction including a component perpendicular to the optical axis) to correct image blur caused by the shake of the interchangeable lens 110. The focus lens 203 adjusts the focus by moving in the optical axis direction. The aperture 204 adjusts the amount of light by changing the aperture diameter.

[0020] The interchangeable lens 110 also has a lens control unit 240. The lens control unit 240 has a zoom driving unit 219, a zoom control unit 224, a lens shake detection unit 220, an OIS position detection unit 218, an OIS driving unit 217, an OIS control unit 221, a focus driving unit 216, a camera information management unit 223, and a lens communication unit 222. The lens control unit 240 is capable of communicating with a camera control unit 215 in the camera 101 via the lens communication unit 222.

[0021] The zoom driving unit 219 includes a zoom motor (not shown) that drives the zoom lens 201. The zoom control unit 224 controls the zoom driving unit 219 in response to a user's zoom operation on the operation unit 214 provided in the camera 101. This changes the focal length.

[0022] The lens shake detection unit 220 detects various shakes (first shakes: hereinafter collectively referred to as hand shake) other than shutter shake, which will be described later, such as camera shake and panning, applied to the interchangeable lens 110. The lens shake detection unit 220 is configured, for example, with a gyro sensor, and outputs a lens shake signal indicating the angular velocity of the camera shake.

[0023] The OIS position detection unit 218 detects the position of the correction lens 202 in a plane (hereinafter referred to as the lens shift plane) perpendicular to the optical axis. The OIS driving unit 217 includes a voice coil motor (VCM) (not shown) that drives the correction lens 202 in the lens shift plane. The OIS control unit 221 calculates an OIS camera shake correction amount (including a correction direction) for correcting (reducing) the camera shake detected by the lens shake detection unit 220, and controls the OIS driving unit 217 so that the correction lens 202 is driven in the lens shift plane according to the OIS camera shake correction amount. At this time, the OIS control unit 221 controls the OIS driving unit 217 while detecting the position of the correction lens 202 via the OIS position detection unit 218. It is to be noted that a configuration may be provided in which the correction lens 202 is fixed (locked) at a reference position that is a position on the optical axis.

[0024] The focus driver 216 includes a focus motor that drives the focus lens 203, and drives the focus motor in response to a focus command from the camera controller 215. The camera controller 215 extracts a specific frequency component from the luminance information obtained through the image sensor 206 in the camera 101 to generate a contrast evaluation value, and transmits a focus command to the focus driver 216 so as to move the focus lens 203 to a position where the contrast evaluation value is maximized. This performs autofocus (AF) using a contrast detection method. Note that AF using a phase difference detection method may also be performed.

[0025] The aperture drive unit 233 includes an aperture motor that drives the aperture 204, and drives the aperture motor in response to an aperture command from the camera control unit 215. The camera control unit 215 transmits an aperture command to the aperture drive unit 233 so that the aperture value (aperture diameter) is set so that an appropriate amount of light reaches the image sensor 206 based on the luminance information.

[0026] The camera information management unit 223 holds and manages various setting information of the camera 101, as well as information such as the position and driving limits of the image sensor 206 in the IIS.

[0027] The camera 101 has a shutter 205 , an image sensor 206 , an AD converter 207 , an image processing circuit 209 , an internal memory 210 , a display unit 211 , a timing generator 208 , a camera control unit 215 , a compression / decompression processing unit 212 , a storage memory 213 and an operation unit 214 .

[0028] The image sensor 206 is composed of a photoelectric conversion element such as a CCD sensor or a CMOS sensor, and converts (captures) the subject image formed by the imaging optical system 200 into an imaging signal as an electrical signal. The image sensor 206 also moves within a plane perpendicular to the optical axis to correct image blur caused by shaking of the camera 101.

[0029] The analog image signal read from the image sensor 206 is converted into a digital image signal by the AD converter 207. The AD converter 207 performs AD conversion as well as noise removal and gain adjustment on the digital image signal. The camera control unit 215 obtains luminance information from the digital image signal output from the AD converter 207, and generates a contrast evaluation value and determines exposure conditions (aperture value and shutter speed) based on the luminance information.

[0030] The shutter 205 is a mechanical shutter, and in this embodiment, it is a focal plane shutter having a front curtain and a rear curtain as light-shielding blades. The focal plane shutter enables exposure for preview imaging or video imaging of the image sensor 206 by opening both the front curtain and the rear curtain, and controls the exposure amount of the image sensor 206 during still image imaging by running the front curtain and the rear curtain at a timing according to the shutter speed. The front curtain and the rear curtain collide with a stopper portion provided on the shutter 205 at a position where their running is completed. As a result, vibration (second vibration: hereinafter referred to as shutter vibration) S occurs as shown in FIG. 1. It is to be noted that a mechanical shutter having only a front curtain may be combined with an electrical reset operation of the image sensor 206 functioning as a rear curtain.

[0031] A timing generator 208 controls the drive timing of the image sensor 206 and the output timing of the AD converter 207 in accordance with instructions from a camera control unit 215. An image processing circuit 209 performs image processing such as pixel interpolation processing and color conversion processing on the digital imaging signal output from the AD converter 207 to generate image data (preview image data and captured image data). The image data is stored in an internal memory 210.

[0032] The display unit 211 displays image data stored in the internal memory 210 and various imaging information. The display unit 211 also plays back and displays captured image data (still images or video data) stored in a storage medium such as a semiconductor memory (not shown) that is detachable from the camera 101.

[0033] The compression / decompression processing unit 212 performs compression and decompression processing on the image data stored in the internal memory 210 in accordance with the image format.

[0034] The storage memory 213 stores various parameters and data required for the operation of the camera control unit 215. The operation unit 214 is a user interface that allows the user to perform various operations.

[0035] The camera control unit 215 is a computer configured with an arithmetic processing unit such as a CPU, and performs operations according to programs stored in the internal memory 210 in response to user operations and various inputs on the operation unit 214. The programs are programs for performing zoom control, anti-shake control, automatic exposure control, AF control, subject detection processing for detecting the face of a subject, etc. The camera control unit 215 has a camera communication unit 231, a shutter control unit 235, a camera shake detection unit 227, an IIS driving unit 225, an IIS position detection unit 228, an IIS control unit 229, a lens information management unit 232, a tripod determination unit 226, and a sensor lock unit 236.

[0036] The camera communication unit 231 performs communication between the camera control unit 215 and the lens control unit 240 through the lens communication unit 222. The shutter control unit 235 controls the travel of the front and rear curtains of the shutter 205.

[0037] The camera shake detection unit 227 detects the above-mentioned camera shake applied to the camera 101. The camera shake detection unit 227 is configured by, for example, a gyro sensor, and outputs a camera shake signal that indicates the angular velocity of the camera shake.

[0038] The IIS position detection unit 228 detects the position of the image sensor 206 in a plane (hereinafter referred to as a sensor shift plane) perpendicular to the optical axis. The IIS driving unit 225 includes a VCM (not shown) that drives the image sensor 206 in the sensor shift plane in the IIS. The IIS control unit 229 calculates an IIS correction amount (including a correction direction) for correcting image blur due to camera shake detected by the camera shake detection unit 227 and shutter shake correction (described later), and controls the IIS driving unit 225 so that the image sensor 206 is driven in the sensor shift plane according to the IIS correction amount. At this time, the IIS control unit 229 controls the IIS driving unit 225 while detecting the position of the image sensor 206 via the IIS position detection unit 228.

[0039] The tripod determination unit 226 determines whether the camera 101 is held by a tripod (hereinafter, referred to as a static state). The determination of whether the camera 101 is held by a tripod may be determined, for example, by whether a switch provided at a connection part of the imaging device 101 to the tripod is pressed, or by whether a user operates the operation unit 214 to input that the camera 101 is held by a tripod. Alternatively, the determination may be determined by whether a state in which the amplitude of the shake detected by the lens shake detection unit 220 is less than a predetermined value continues for a predetermined period. The lens information management unit 232 holds and manages information on the optical characteristics of the OIS, information on the positions (zoom position, focus position, aperture position) and drive limits of the movable parts in the imaging optical system 200, and identification information (lens ID) of the interchangeable lens 110.

[0040] The sensor lock unit (fixing means) 236 fixes the image sensor 206 at a reference position, which is a position on the optical axis in the sensor shift plane. This fixation prevents the image sensor 206 from moving even if an external shock is applied to the camera 101, making it possible to suppress image blurring.

[0041] FIG. 4 shows the detailed configuration of the OIS control system on the interchangeable lens side and the IIS control system on the camera side.

[0042] The OIS control unit 221 has a lens filter processing unit 255 , a lens integration unit 245 , an OIS correction amount calculation unit 244 , a lens ratio calculation unit 243 , a lens control method determination unit 246 , an OIS driving range limit unit 242 and a lens PID control unit 241 .

[0043] In the OIS control unit 221, the angular velocity of the camera shake (lens shake signal) detected by the lens shake detection unit 220 is converted into a shake angle by being integrated by the lens integration unit 245 via the lens filter processing unit 255.

[0044] The lens filter processing unit 255 performs processing to change the amplitude and frequency of the camera shake depending on the magnitude of the amplitude and frequency, and mainly performs processing to prepare for the time when the camera shake has converged by increasing the force that returns the correction lens 202 to the reference position on the optical axis for camera shake with large amplitude that reaches the vibration isolation limit.

[0045] The OIS correction amount calculation unit 244 calculates the OIS camera shake correction amount, which is the drive amount of the image sensor 206 for correcting image blur caused by camera shake (shake angle), taking into account the frequency band of the shake angle and the driveable range of the correction lens 202.

[0046] The lens ratio calculation unit 243 calculates the correction ratio to be performed by the OIS when the sum of the IIS correction amount and OIS correction amount, which are calculated on the camera side and will be described later, is taken as 100%.

[0047] The lens control method determination unit 246 determines whether to select a vibration reduction control method (OIS / IIS cooperative control method, OIS only method, or IIS only method). Note that in this embodiment, a description of the OIS only method is omitted.

[0048] The OIS drive range limiter 242 limits the OIS camera shake correction amount, that is, if the target position to which the correction lens 202 is driven in response to camera shake exceeds the drive limit of the correction lens 202 .

[0049] The lens PID control unit 241 performs feedback control using the current position of the compensation lens 202 acquired by the OIS position detection unit 218 so that the compensation lens 202 is driven to a target position. However, the feedback control method is not limited to PID control.

[0050] The IIS control unit (control means) 229 has a camera filter processing unit 254, a camera integration unit 251, an IIS correction amount calculation unit 250, a camera shutter shake correction control unit 230, a camera ratio calculation unit 249, a camera control method determination unit 252, a driving range subtraction unit 253, an IIS driving range limit unit 248, and a camera PID control unit 247.

[0051] In the IIS control unit 229, the angular velocity of the camera shake (camera shake signal) detected by the camera shake detection unit 227 is converted into a shake angle by being integrated by the camera integration unit 251 via the camera filter processing unit 254 in the IIS control unit 229.

[0052] The camera filter processing unit 254 performs processing to change the amplitude and frequency of the shake depending on the magnitude of the amplitude and frequency, and mainly performs processing to prepare for the time when the shake converges by increasing the force that returns the image sensor 206 to the reference position on the optical axis in response to large amplitude shake that reaches the vibration isolation limit.

[0053] The IIS correction amount calculation unit 250 calculates an IIS camera shake correction amount, which is the drive amount of the image sensor 206 for correcting image blur caused by camera shake (shake angle), taking into account the frequency band of the shake angle and the drivable range of the image sensor 206.

[0054] The camera shutter shake correction control unit 230 determines whether or not to perform shutter shake correction. Shutter shake correction is to control the IIS so as to reduce the relative displacement between the main body of the camera 101 (hereinafter referred to as the camera body) caused by shutter shake and the image sensor 206 movably held by the main body. Specifically, it is to drive the image sensor 206 in the same direction as the shaking direction of the camera body caused by shutter shake.

[0055] Furthermore, the camera shutter shake compensation control unit 230 prestores an IIS shutter shake compensation amount, which is the drive amount of the image sensor 206 for shutter shake compensation, and when performing shutter shake compensation, calculates the IIS compensation amount by adding the IIS shutter shake compensation amount to the IIS hand shake compensation amount. The timing at which the IIS shutter shake compensation amount is added to the IIS hand shake compensation amount is the exposure start timing described above.

[0056] As shown in the figure, the OIS control unit 221 may be provided with a lens shutter shake correction control unit 256. The lens shutter shake correction control unit 256, like the camera shutter shake correction control unit 230, determines whether or not to perform shutter shake correction that controls the OIS to reduce the relative displacement between the imaging optical system 200 (a portion excluding the correction lens 202) and the correction lens 202 due to shutter shake. In shutter shake correction, the correction lens 202 is driven in the same direction as the shake direction of the imaging optical system due to shutter shake. In this case, the lens shutter shake correction control unit 256 stores in advance an OIS shutter shake correction amount, which is the drive amount of the correction lens 202 for shutter shake correction, and calculates the OIS correction amount by adding the OIS shutter shake correction amount to the OIS hand shake correction amount. The timing at which the OIS shutter shake correction amount is added to the OIS hand shake correction amount is the timing at which the exposure start timing at which still image capture is started is received from the camera control unit 215 by communication.

[0057] The OIS shutter shake compensation amount may be changed according to the imaging device 101 to which the interchangeable lens 110 is attached, or the OIS shutter shake compensation amount may be received from the attached imaging device 101 via the lens communication unit 222. Alternatively, the OIS shutter shake compensation amount received from the attached imaging device 101 via the lens communication unit 222 may be corrected according to the characteristics of the interchangeable lens 110, and the corrected OIS shutter shake compensation amount may be used.

[0058] When it is determined by the camera shutter shake correction control unit 230 that shutter shake correction is to be performed, the driving range subtraction unit 253 subtracts the IIS shutter shake correction amount from the driving range of the image sensor 206 for correcting camera shake. The subtraction of the driving range of the image sensor 206 by the driving range subtraction unit 253 will be described in detail later.

[0059] A camera ratio calculation unit 249 calculates the correction ratio to be performed by the IIS when the sum of the IIS correction amount (the IIS camera shake correction amount when the IIS shutter shake correction amount is not added) and the OIS correction amount is set to 100%.

[0060] The camera control method determination unit 252 determines whether to select a vibration reduction control method. The IIS drive range limit unit 248 limits the IIS camera shake correction amount, i.e., the amount of IIS camera shake correction when the target position to which the image sensor 206 is driven against camera shake exceeds the drive limit of the image sensor 206.

[0061] The camera PID control unit 247 performs feedback control so that the image sensor 206 is driven to a target position, using the current position of the image sensor 206 acquired by the IIS position detection unit 228. However, the feedback control method is not limited to PID control.

[0062] FIG. 5 shows an example of time change in the IIS correction amount when camera shake correction by IIS and shutter shake correction are performed simultaneously. The vertical axis shows the shake correction amount, and the horizontal axis shows time. In FIG. 5, the target position of the image sensor 206 corresponding to the IIS camera shake correction amount calculated by the IIS correction amount calculation unit 250 (or the IIS driving range limit unit 248) is shown by a dotted line as a camera shake correction waveform. Also, the position of the image sensor 206 corresponding to the IIS shutter shake correction amount stored in advance in the storage memory 213 is shown by a dashed line as a shutter shake correction waveform. This shutter shake correction waveform is uniquely determined by the relationship between the camera body and the image sensor 206, and whether or not to add it to the camera shake correction waveform is determined according to the optical characteristics (parallel eccentricity sensitivity) of the OIS. In this embodiment, when the parallel decentering sensitivity of the OIS is a negative value, i.e., when the OIS has optical characteristics that move the subject image in the opposite direction to the direction of shutter shake when shutter shake occurs in the camera body, the shutter shake compensation waveform is added to the camera shake compensation waveform. In other words, when shutter shake occurs in the camera body and the parallel decentering degree of the OIS is a negative value, the shutter shake is emphasized, so when a certain condition is met (when the parallel decentering degree of the OIS is a negative value), the camera shake compensation waveform is corrected in the direction that reduces the shutter shake.

[0063] In addition, the shutter shake compensation waveform is a waveform that is formed independently of the camera shake compensation waveform, and furthermore, the shutter shake compensation waveform is a waveform with a sufficiently high frequency compared to the camera shake compensation waveform. Therefore, shutter shake does not affect the camera shake compensation waveform. In other words, the shutter shake compensation waveform and the camera shake compensation waveform are not mutually dependent. As a result, when image blur caused by camera shake and shutter shake is corrected simultaneously, the waveform is a simple addition waveform of a low-frequency camera shake compensation waveform and a high-frequency shutter shake compensation waveform, as shown by the solid line.

[0064] Fig. 6(a) shows the OIS / IIS cooperative control method, and Fig. 6(b) shows the IIS-only method. In the OIS / IIS cooperative control method shown in Fig. 6(a), a combined control of both the OIS and IIS is performed to maximize the image stabilization effect during exposure, and image stabilization control is performed using only one of the OIS during periods other than exposure. Here, we will explain the case where image stabilization control is performed only using the OIS during periods other than exposure, and the IIS is stopped at a reference position. However, image stabilization control may also be performed only using the IIS during periods other than exposure, with the OIS stopped at a reference position.

[0065] In the OIS / IIS cooperative control method, a correction ratio (control ratio) to be shared between the OIS and IIS is determined when the total amount of OIS correction amount and IIS correction amount is 100%. The correction ratio may be determined by either the OIS control unit 221 or the IIS control unit 229, but in this embodiment, it is the OIS control unit 221 that determines the correction ratio. In this case, information on the driving range of the image sensor 206 in the IIS (hereinafter referred to as the IIS driving range) is transmitted to the OIS control unit 221.

[0066] The OIS control unit 221, which has received the information on the IIS driving range, determines an OIS ratio, which is a correction ratio for the OIS, and an IIS ratio, which is a correction ratio for the IIS, while taking into consideration the driving range of the correction lens 202 in the OIS (hereinafter referred to as the OIS driving range). Then, it transmits the determined IIS ratio to the IIS control unit 229. Note that, when the IIS control unit 229 determines the correction ratio, the IIS control unit 229 transmits the OIS ratio of the determined OIS ratio and IIS ratio to the OIS control unit 221.

[0067] In the IIS-only method shown in Fig. 6(b), unlike the OIS / IIS cooperative control method, image stabilization control is performed only on the IIS, so image stabilization control of the IIS is performed not only during exposure but also outside of exposure. In this case, in order to maximize the image stabilization effect during exposure, it is effective to stop (remain) the IIS at the reference position as much as possible outside of exposure.

[0068] 7(a) and (b) show examples of the division ratio of the correction ratio between OIS and IIS (OIS ratio and IIS ratio). There are several methods (factors) for determining the correction ratio, but here we will explain the two main methods. I) Image stabilization priority method that determines the correction ratio based on the OIS driving range and the IIS driving range II) Image quality priority method in which the correction ratio is determined so as to minimize image degradation FIG. 7(a) shows the OIS ratio and IIS ratio in I) anti-shake priority method and II) image quality priority method when shutter shake correction is not performed. In I), the OIS ratio:IIS ratio = 40%:60%, which shows the case where the IIS driving range is about 10% larger than the OIS driving range. In II), the OIS ratio:IIS ratio = 50%:50%, which shows the case where the IIS driving range is not used to its limit in consideration of image quality degradation. In II), the anti-shake effect of combining OIS and IIS is slightly lower than in I), but the correction ratio is determined by prioritizing image quality.

[0069] FIG. 7(b) shows the OIS ratio and IIS ratio in I) and II) when shutter shake compensation is performed. In I), an IIS driving range that is reduced by the driving range used in shutter shake compensation is used, and the IIS ratio is reduced from 60% when shutter shake compensation is not performed to 55%. As a result, the OIS ratio is increased from 40% when shutter shake compensation is not performed to 45%. In this case, the image stabilization performance when a large camera shake is applied is reduced by the equivalent of 5%, but when a large camera shake is not applied, 100% image stabilization can be achieved with OIS and IIS, so there is no deterioration in image stabilization performance. Also, in II), the entire IIS driving range is not used originally, so there is no change in the IIS and OIS image stabilization range and the IIS and OIS ratio from when shutter shake compensation is not performed. For this reason, the IIS driving range is reduced when shutter shake correction is performed, but by notifying the OIS of this reduction, an appropriate correction ratio that balances image stabilization performance, image quality, and shutter shake correction is determined.

[0070] 8(a) and (b) show changes in the sensitivity of the cutoff frequency (hereinafter referred to as cutoff sensitivity) in the filter processing performed by the camera filter processor 254. The vertical axis shows the cutoff frequency of the filter processing, and the horizontal axis shows the amplitude of camera shake (hereinafter referred to as shake amplitude). The shake amplitude may be replaced with the frequency of camera shake. FIG. 8(a) shows the case where the cutoff sensitivity is low, and FIG. 8(b) shows the case where the cutoff sensitivity is high.

[0071] In either case, the cutoff frequency increases as the vibration amplitude increases, but when the cutoff sensitivity is high, the slope of the increase in the cutoff frequency is steeper than when the cutoff sensitivity is low, and the cutoff frequency increases to a large value. When the cutoff frequency is high, the IIS remains at the reference position and the force of returning becomes stronger, but the vibration isolation performance decreases. This increases the opportunities to maximize the vibration isolation effect during exposure, but has the disadvantage that image blur remains for large vibration amplitudes. For this reason, it is preferable to set the cutoff sensitivity in consideration of the balance between the vibration isolation effect and the remaining image blur.

[0072] Fig. 9(a) shows the IIS driving range when shutter shake compensation is not performed, and Fig. 9(b) shows the IIS driving range when shutter shake compensation is performed. The vertical axis shows the IIS driving range in the up / down (Pitch) direction, and the horizontal axis shows the IIS driving range in the left / right (Yaw) direction.

[0073] When shutter shake correction is not performed as shown in Fig. 9(a), the image sensor 206 can be driven for camera shake correction within an octagonal maximum IIS driving range. In contrast, when shutter shake correction is performed as shown in Fig. 9(b), the image sensor 206 can be driven for camera shake correction within an IIS driving range that is smaller than the maximum IIS driving range by the range (shaded area) in which the image sensor 206 is driven for shutter shake correction. The driving range subtraction unit 253 performs processing to subtract the shaded area from the maximum IIS driving range. As a result, a vibration reduction effect against shutter shake is obtained, but the vibration reduction effect against large camera shake is reduced.

[0074] Although the IIS driving range is octagonal in this example, it may be of another shape, such as a rectangle.

[0075] FIG. 10(a) shows the OIS shutter shake compensation amount (shutter shake compensation waveform) (upper diagram) and IIS shutter shake compensation amount (lower diagram) according to focal length when an interchangeable lens 110 with a long maximum focal length of the imaging optical system 200 is used. The vertical axis is the shutter shake compensation amount, and the horizontal axis is the focal length. Note that, although the shutter shake compensation amount will be explained here, in the case of the phase of the shutter shake compensation amount, the magnitude of the shutter shake compensation effect is determined according to the degree of agreement with the phase of the shutter shake. The magnitude and phase of the shutter shake compensation amount correspond to the control characteristics of the IIS in shutter shake compensation.

[0076] The upper diagram in Fig. 10(a) shows that the effect of shutter shake correction by the OIS is small on the wide-angle side and extremely large on the telephoto side. In particular, when the maximum focal length of the imaging optical system 200 is long, image shake is noticeable on the telephoto side, so it is preferable to maximize the effect of shutter shake correction on the telephoto side. In this case, when the parallel decentering sensitivity of the OIS is a negative value, image shake due to shutter shake can be appropriately corrected by maximizing the effect of shutter shake correction by the IIS on the wide-angle side, as shown in the lower diagram in Fig. 10(a).

[0077] 10(b) shows the OIS shutter shake compensation amount (upper diagram) and the IIS shutter shake compensation amount (lower diagram) according to the focal length when an interchangeable lens 110 with a short maximum focal length is used for the imaging optical system 200. The vertical axis is the shutter shake compensation amount, and the horizontal axis is the focal length.

[0078] The upper diagram in FIG. 10(b) shows that the effect of shutter shake compensation by the OIS is large on the wide-angle side and small on the telephoto side. In particular, when the maximum focal length of the imaging optical system 200 is short, there is not much difference in the effect of shutter shake compensation between the wide-angle side and the telephoto side. For this reason, it is preferable to set the effect of shutter shake compensation based on the wide-angle side. In this case, when the parallel decentering sensitivity of the OIS is a negative value, good shutter shake compensation can be achieved by mitigating the effect of shutter shake compensation by the IIS on the wide-angle side and gradually increasing it toward the telephoto side, as shown in the lower diagram in FIG. 10(b).

[0079] 11(a) and (b) show calculation of the IIS correction amount in a static state. Here, the static state is shown by fixing the camera 101 to a tripod mount in a normal position (a position where the optical axis direction and the gravity direction are perpendicular to each other), but the static state may be achieved by other methods, for example, by using a holding member including a gimbal mechanism.

[0080] Fig. 11(a) shows the process of calculating the IIS correction amount, and Fig. 11(b) shows the relationship between the gain used in the process and the optical characteristics. As shown in Fig. 11(a), the IIS correction amount is calculated by adding the IIS shutter shake compensation amount to the IIS camera shake compensation amount for compensating for low-frequency camera shake that may occur even in a static state. In this case, depending on the rigidity of the tripod for keeping the camera 101 in a static state, if the IIS shutter shake compensation amount is added directly to the IIS camera shake compensation amount when the parallel decentering sensitivity of the OIS is a negative value, the IIS will be overcorrected, causing image blur.

[0081] Therefore, as shown in FIG. 11(b), a gain to be applied to the IIS shutter shake compensation amount is set, and the IIS shutter shake compensation amount to be added to the IIS camera shake compensation amount is adjusted. For example, when the OIS has optical characteristic 1 with a large negative parallel eccentricity sensitivity, the IIS shutter shake compensation amount (the driving amount of the image sensor 206 for shutter shake) to be added in the pitch direction and the yaw direction is reduced to prevent overcorrection by the IIS. When the OIS has optical characteristic 3 with a small negative parallel eccentricity sensitivity, no positional deviation between the OIS and IIS occurs due to shutter shake, so the IIS shutter shake compensation amount is not added. When the OIS has optical characteristic 2 with a negative parallel eccentricity sensitivity intermediate between optical characteristics 1 and 3, the difference between the shutter shake in the pitch direction and the shutter shake in the yaw direction due to the tripod fixation becomes large, and a difference occurs in the image shake amount in the pitch direction and the yaw direction. For this reason, a difference is provided in the gain between the pitch direction and the yaw direction (in the figure, the IIS shutter shake compensation amount is added only in the yaw direction).

[0082] In this embodiment, the case where the gain is made different by dividing the optical characteristics of the OIS into three has been described, but the gain may be made different by dividing the optical characteristics of the OIS into two or four or more. Also, the IIS shutter shake compensation amount to be added to the IIS camera shake compensation amount may be changed by a method other than changing the gain. EXAMPLES

[0083] The flowchart in FIG. 12 shows an IIS control process (control method) that the IIS control unit 229 executes according to a program in the first embodiment.

[0084] In step S1201, the camera shutter shake correction control unit 230 performs a shutter shake correction determination process. Details will be described later, but the input data for this process are lens information and shutter type, and the output data is a shutter shake correction flag. When shutter shake correction is performed, the shutter shake correction flag is set to ON, and when shutter shake correction is not performed, the shutter shake correction flag is set to OFF. The case where the shutter shake correction flag is ON will be described below.

[0085] In step S1202A, the IIS control unit 229 starts an anti-shake calculation loop at a predetermined sampling period. In the anti-shake calculation loop, first, in step S1203, the camera filter processing unit 254 acquires a camera shake signal (angular velocity) from the camera shake detection unit 227 and performs the above-mentioned filter process on the camera shake signal.

[0086] Next, in step S1204, camera integration unit 251 performs integration processing on the camera shake signal to obtain the shake angle.

[0087] Next, in step S1205, IIS correction amount calculation section 250 calculates the amount of IIS camera shake correction in consideration of the amplitude and frequency band of the shake angle.

[0088] Next, in step S1206, camera shutter shake correction control unit 230 determines whether it is time to drive shutter 205 (shutter drive timing is ON). If the shutter drive timing is ON, in step S1207, the shutter shake correction amount is added to the IIS camera shake correction amount, and if the vibration compensation calculation loop has not ended in step S1202B, the process proceeds to step S1208. If the shutter drive timing is OFF, in step S1202B, the vibration compensation calculation loop has not ended in step S1208.

[0089] In step S1208, the camera PID control unit 247 performs feedback control of the drive of the image sensor 206 for IIS. Then, the IIS control unit 229 ends the IIS control process.

[0090] The flowchart in FIG. 13 shows the shutter shake correction determination process performed by the camera shutter shake correction control unit 230 in step S1201 in FIG.

[0091] In step S1301, the camera shutter shake correction control unit 230 acquires the parallel decentering sensitivity of the OIS, which is lens information, from the interchangeable lens 110 (OIS control unit 221). This parallel decentering sensitivity is a numerical value notified by the interchangeable lens 110, and its sign and scalar amount are values ​​that are not related to shutter shake at all.

[0092] Next, in step S1302, camera shutter shake correction control unit 230 judges whether shutter 205 is of a mechanical shutter type (hereinafter abbreviated as "mechanical shutter") or of another type. If it is of a mechanical shutter type, shutter shake occurs, so in the next step S1303, it is judged whether the parallel decentering sensitivity is a negative value or not (positive value). In other words, it is judged whether the OIS has optical characteristics that move the subject image in the direction opposite to the direction of shutter shake when shutter shake occurs in the camera body due to driving of shutter 205.

[0093] Next, if the parallel decentering sensitivity is a negative value in step S1303, the camera shutter shake compensation control unit 230 turns on the shutter shake compensation flag in step S1304, and then ends this process.

[0094] Next, if the shutter 205 is of a type other than a mechanical shutter type in step S1302, or if the parallel decentering sensitivity is a positive value in step S1303, the camera shutter shake correction control unit 230 turns off the shutter shake correction flag in step S1305. Then, this process ends.

[0095] The sign of the parallel decentering sensitivity of the OIS is determined by the relationship between the subject and the subject image formed on the image sensor 206. For this reason, the sign may be reversed. If the shutter shake correction flag is ON, shutter shake correction is performed by the following process.

[0096] The flowchart in FIG. 14 shows a shutter shake correction determination process different from that in FIG. 13, which is performed by the camera shutter shake correction control unit 230 in step S1201 in FIG.

[0097] In step S1401, the camera shutter shake correction control unit 230 acquires a lens ID, which is lens information, from the lens information management unit 232. The camera shutter shake correction control unit 230 identifies the type and model of the interchangeable lens 110 attached to the camera 101 from the lens ID.

[0098] Next, in step S1402, camera shutter shake correction control unit 230 determines whether shutter 205 is a mechanical shutter type or another type. If it is a mechanical shutter type, in the next step S1403, it determines whether the lens ID matches the lens ID of an interchangeable lens that performs shutter shake correction (that is, the parallel decentering sensitivity of the OIS is a negative value) that is registered in advance in storage memory 213. If they match, in step S1404, the shutter shake correction flag is turned ON. Then, this process ends.

[0099] If the shutter 205 is not a mechanical shutter in step S1402, or if the lens ID does not match the registered lens ID in step S1403, the camera shutter shake correction control unit 230 turns off the shutter shake correction flag in step S1405. Then, this process ends.

[0100] The lens ID of an interchangeable lens that performs shutter shake compensation may be registered in advance according to the positive or negative parallel decentering sensitivity of the OIS. Also, interchangeable lenses that are light in weight and prone to shaking due to disturbances may be registered in advance. Furthermore, the lens ID of an interchangeable lens that performs shutter shake compensation may be registered in accordance with other conditions.

[0101] Fig. 15(a) shows an example of the change over time of the IIS shutter shake compensation amount (shutter shake compensation waveform). The vertical axis shows the IIS shutter shake compensation amount, and the horizontal axis shows time. Fig. 15(b) is a table showing the IIS shutter shake compensation amount (control data) for each time from the start of exposure. This table is stored in the storage memory 213.

[0102] When performing shutter shake compensation, the camera shutter shake compensation control unit 230 calculates the IIS compensation amount by adding the IIS shutter shake compensation amount 1 um to the IIS camera shake compensation amount, for example, at time p2 after the start of exposure.

[0103] 15B is merely an example, and the IIS shutter shake compensation amount for each time may be other values. Also, a table in which the IIS shutter shake compensation amount differs for each lens ID may be stored. EXAMPLES

[0104] 16 shows a flowchart of shutter shake correction determination processing performed by the camera shutter shake correction control unit 230 in the embodiment 2. This processing is performed in step S1201 in FIG.

[0105] Image blur caused by shutter shake is easily noticeable when the shutter speed is relatively short, for example, 1 / 400 to 1 / 20 seconds. Camera shake is less likely to occur when the shutter speed is short, although this depends on the focal length of the imaging optical system and the individual differences of the user. On the other hand, shutter shake occurs due to the operation of the shutter regardless of individual differences. For this reason, when the shutter speed is set to 1 / 400 seconds, shutter shake occurs and image blur is noticeable even if camera shake does not occur.

[0106] Also, when the shutter speed is shorter, such as 1 / 500 seconds, neither camera shake nor shutter shake occurs easily. Furthermore, when the shutter speed is longer than 1 / 20 seconds, shutter shake becomes less noticeable. This is because the longer the exposure time, the shorter the period of time that the camera is affected by shutter shake.

[0107] Image blur caused by shutter shake is corrected by IIS at the same time as image blur caused by camera shake, so performing shutter shake correction reduces the IIS driving range for camera shake correction. If shutter shake correction is performed at a long shutter speed, the IIS driving range for camera shake correction narrows even though the effect is small. For this reason, in this embodiment, shutter shake correction is performed only in the case of a shutter speed within a predetermined range that is significantly affected by shutter shock.

[0108] The processing from step S1601 to step S1603 in Fig. 6 is the same as step S1301 to step S1303 in Fig. 13. If the shutter 205 is a mechanical shutter type in step S1602 and the parallel decentering sensitivity of the OIS is a negative value in step S1603, the camera shutter shake correction control unit 230 determines the shutter speed in the next step S1604.

[0109] If the shutter speed is set within the predetermined range of 1 / 400 to 1 / 20 seconds, the camera shutter shake correction control unit 230 turns the shutter shake correction flag ON in step S1605, and then ends this process.

[0110] If the shutter 205 is of a type other than a mechanical shutter type in step S1602, if the parallel decentering sensitivity is a positive value in step S1603, or if the shutter speed is shorter than 1 / 400 seconds or longer than 1 / 20 seconds in step S1604, the process proceeds to step S1606. In step S1606, the camera shutter shake correction control unit 230 turns off the shutter shake correction flag. Then, this process ends. EXAMPLES

[0111] 17 shows a flowchart of shutter shake correction determination processing performed by the camera shutter shake correction control unit 230 in the embodiment 3. This processing is performed in step S1201 in FIG.

[0112] In step S1701, the camera shutter shake correction control unit 230 receives lens information from the interchangeable lens 110 (OIS control unit 221). This lens information is information indicating whether the interchangeable lens 110 is an interchangeable lens for which shutter shake correction should be performed (TRUE) or not (FALSE). An interchangeable lens for which shutter shake correction should be performed is an interchangeable lens for which the parallel decentering sensitivity of the OIS has a negative value.

[0113] Next, step S1702 is the same as step S1302 in Fig. 13. If the shutter 205 is a mechanical shutter type, the camera shutter shake correction control unit 230 determines the lens information in step S1703.

[0114] If the lens information is TRUE in step S1703, the camera shutter shake correction control unit 230 turns the shutter shake correction flag ON in step S1704, and then ends this process.

[0115] If the shutter 205 is of a type other than the mechanical shutter type in step S1702, or if the lens information is FALSE in step S1703, the camera shutter shake correction control unit 230 turns the shutter shake correction flag OFF in step S1705, and then ends this process.

[0116] In this embodiment, the lens information indicates whether or not the interchangeable lens is an interchangeable lens that should be subjected to shutter shake correction, but other lens information may be used. For example, the susceptibility of the interchangeable lens to the effects of shutter shake may be evaluated in advance, and an evaluation value of 0 to 3 may be received by the camera shutter shake correction control unit 230 as the lens information. The camera shutter shake correction control unit 230 does not perform shutter shake correction when the evaluation value is 0, and performs shutter shake correction when the evaluation value is 1 to 3, and reduces the amount of shutter shake correction as the smaller the evaluation value, the smaller the effect of shutter shake is considered to be. EXAMPLES

[0117] The flowchart in FIG. 18 shows an IIS control process (control method) that the IIS control unit 229 executes according to a program in the fourth embodiment.

[0118] The processing from step S1801 to step S1803 is the same as the processing from step S1201 to step S1203 in FIG.

[0119] In step S1804, the camera filter processing unit 254 performs a filtering process, which will be described in detail later, in which the cutoff frequency is changed in accordance with the vibration amplitude.

[0120] When the image stabilization control method is the OIS / IIS cooperative control method, the OIS is controlled except during exposure, and the IIS is fixed at the reference position. In other words, if the cutoff frequency is changed during exposure when the OIS and IIS are cooperatively controlled, residual image blur is likely to occur, so the cutoff frequency is usually fixed.

[0121] The processes in steps S1805 and S1806 are the same as those in steps S1204 and S1205 in FIG.

[0122] In step S1807, the camera ratio calculation unit 249 calculates the IIS driving range and the correction ratio (here, the IIS ratio). Although details will be described later, the input data for this process is the vibration isolation control method and the shutter shake correction flag, and the output data is the correction ratio.

[0123] Next, in step S1808, camera ratio calculation unit 249 performs a process of multiplying the IIS ratio. Specifically, in the OIS / IIS cooperative control method, the IIS image stabilization amount is output after multiplying the IIS ratio by the IIS image stabilization amount. In the IIS only method, since the IIS ratio is 100%, the IIS image stabilization amount is output as is.

[0124] Next, in step S1809, if the position of the image sensor 206 corresponding to the IIS camera shake compensation amount exceeds the IIS driving range, IIS driving range limiter 248 imposes a limit on the IIS camera shake compensation amount.

[0125] Next, in step S1810, camera shutter shake compensation control unit 230 determines whether the shutter drive timing is ON or not, and if it is ON, performs shutter shake compensation selection processing according to the focal length in step S1811. Although details will be described later, the input data for this processing is the focal length, and the output data is the shutter shake compensation amount selected according to the focal length.

[0126] The processes in steps S1812, S1802B, and S1813 are the same as the processes in steps S1207, S1202B, and S1208 in FIG.

[0127] The flowchart in FIG. 19 shows the calculation process of the IIS driving range and the correction ratio performed by the camera ratio calculation unit 249 in step S1807 in FIG.

[0128] In step S1901, the camera ratio calculation unit 249 determines whether the image stabilization control method is the OIS / IIS cooperative control method or the IIS only method. If the image stabilization control method is the OIS / IIS cooperative control method, in step S1902, it is determined whether the shutter shake correction flag is ON or OFF, and if it is ON, in step S1903, the shutter shake correction amount is subtracted from the IIS driving range.

[0129] Next, in step S1904, the camera ratio calculation unit 249 transmits information on the subtracted IIS driving range to the interchangeable lens 110 (OIS control unit 221). The lens ratio calculation unit 243 of the OIS control unit 221 that has received the information on the subtracted IIS driving range calculates an OIS ratio according to the IIS driving range and transmits it to the camera ratio calculation unit 249. That is, the OIS is made to bear the IIS driving range that has been reduced by the amount of shutter shake correction.

[0130] In step S1905, the OIS ratio is received from the lens ratio calculation unit 243. Then, this process ends.

[0131] On the other hand, if the shutter shake compensation flag is OFF in step S1902, the camera ratio calculation unit 249 calculates the IIS driving range without subtracting the shutter shake compensation amount in step S1906. As in steps S1904 and S1905, the camera ratio calculation unit 249 transmits information on the IIS driving range to the OIS control unit 221 in step S1907, and receives the OIS ratio calculated by the lens ratio calculation unit 243 in step S1908. Then, this process ends.

[0132] If the image stabilization control method is the IIS only method in step S1901, then in step S1909 it is determined whether the shutter shake correction flag is ON or OFF, and if it is ON, then in step S1910 the shutter shake correction amount is subtracted from the IIS driving range. Then in step S1912 the IIS ratio is set to 100% and this process ends.

[0133] On the other hand, if the shutter shake compensation flag is OFF in step S1909, the camera ratio calculation unit 249 calculates the IIS driving range without subtracting the shutter shake compensation amount in step S1911. Then, in step S1912, the IIS ratio is set to 100%, and this process ends.

[0134] The flowchart in FIG. 20 shows the filtering process performed by the camera filtering unit 254 in step S1804 in FIG.

[0135] In step S2001, the camera filter processor 254 determines the anti-shake control method, and if it is the OIS / IIS cooperative control method, fixes the cutoff frequency of the filter processing in step S2003. On the other hand, if the anti-shake control method is the IIS only method, the camera filter processor 254 determines whether or not exposure is in progress in step S2002. If exposure is in progress, the cutoff frequency is fixed in step S2003, and if not exposure, determines whether the shutter shake correction flag is ON or OFF in step S2004.

[0136] When the shutter shake correction flag is ON, the camera filter processing unit 254 increases the cutoff sensitivity of the filter processing in step S2005 because the IIS driving range is reduced by the shutter shake correction during exposure. When the cutoff sensitivity is increased, it becomes more sensitive to the shake amplitude, and the cutoff frequency is more likely to increase, so that the IIS is more likely to remain near the reference position when not being exposed. Therefore, even if the IIS driving range is reduced by the amount of shutter shake correction during exposure, the impact on the vibration reduction effect can be reduced. Then, the camera filter processing unit 254 makes the cutoff frequency variable in step S2007, and ends this process.

[0137] On the other hand, if the shutter shake correction flag is OFF in step S2004, the camera filter processing unit 254 lowers the cutoff sensitivity of the filter processing in step S2006. This is because shutter shake correction is not performed. Then, the camera filter processing unit 254 makes the cutoff frequency variable in step S2007, and ends this process.

[0138] The flowchart in FIG. 21 shows the shutter shake compensation selection process according to the focal length performed by the camera shutter shake compensation control unit 230 in step S1811 in FIG.

[0139] In step S 2101 , the camera shutter shake correction control unit 230 acquires information on the current focal length of the imaging optical system 200 from the OIS control unit 221 .

[0140] Next, in step S2102, camera shutter shake correction control unit 230 determines whether the focal length has been changed during the exposure period. The change in focal length can be determined by comparing the current focal length with the previous focal length by saving the current focal length as the previous value in the final step S2106 of this process.

[0141] If the focal length is changed during the exposure period, the camera shutter shake correction control unit 230 determines in step S2103 whether the change in the IIS shutter shake correction amount relative to the change in focal length is equal to or greater than a predetermined value. The previously described FIG. 10(a) shows an example in which the change in the IIS shutter shake correction amount relative to the change in focal length is equal to or greater than a predetermined value. In this case, changing the amplitude of the IIS shutter shake correction amount during the exposure period may result in an image blur greater than the shutter shake, so the camera shutter shake correction control unit 230 does not change the amplitude of the IIS shutter shake correction amount in step S2104 and leaves it as it is.

[0142] Then, in step S2106, the camera shutter shake correction control unit 230 stores the focal length acquired in step S2101 as the previous focal length, and ends this process.

[0143] 10(b), which has been described above, shows an example in which the change in the IIS shutter shake compensation amount relative to the change in focal length is smaller than a predetermined value. In this case, by changing the amplitude of the IIS shutter shake compensation amount during the exposure period, the effect of reducing image blur caused by shutter shake can be expected, so the camera shutter shake compensation control unit 230 performs processing to change the shutter shake compensation amount in step S2105. Details will be described later, but in this processing, at least one of the amplitude and phase of the IIS shutter shake compensation amount is changed according to the focal length.

[0144] Thereafter, in step S2106, camera shutter shake correction control unit 230 stores the focal length acquired in step S2101 as the previous focal length, and ends this process.

[0145] FIG. 22 shows the process of changing the shutter shake compensation amount performed by the camera shutter shake compensation control unit 230 in step S2105 of FIG.

[0146] In step S2201, camera shutter shake correction control unit 230 determines whether shutter shake correction by OIS is enabled or disabled by communicating with OIS control unit 221. If shutter shake correction by OIS is disabled, camera shutter shake correction control unit 230 sets the amplitude (and at least one of the phase) of the IIS shutter shake correction amount according to the current focal length in step S2205.

[0147] Furthermore, if the shutter shake correction by OIS is effective, the camera shutter shake correction control unit 230 determines in step S2202 whether the effect of the shutter shake correction by OIS is higher on the telephoto side. If the effect of the shutter shake correction is higher on the telephoto side, the amplitude of the OIS shutter shake correction amount on the telephoto side becomes larger as shown in FIG. 10(a). In other words, the residual image blur caused by shutter shake is reduced on the telephoto side. For this reason, the camera shutter shake correction control unit 230 reduces the amplitude of the IIS shutter shake correction amount on the telephoto side in step S2203.

[0148] On the other hand, if the effect of shutter shake correction by the OIS is higher on the wide-angle side, the amplitude of the OIS shutter shake correction amount on the wide-angle side becomes larger as shown in Fig. 10(b). In other words, the residual image blur caused by shutter shake is reduced on the wide-angle side. For this reason, in step S2203, the camera shutter shake correction control unit 230 reduces the amplitude of the IIS shutter shake correction amount on the wide-angle side.

[0149] In this way, the amplitude of the OIS shutter shake compensation amount (amount of drive of the compensation lens 202) and the amplitude of the IIS shutter shake compensation amount (amount of drive of the image sensor 206) change inversely proportional to each other in response to changes in focal length. EXAMPLES

[0150] The flowchart in Fig. 23 shows a shutter shake compensation selection process according to a static state performed by the camera shutter shake compensation control unit 230 in the embodiment 5. This process is performed instead of or together with the shutter shake compensation selection process according to the focal length in step S1811 in Fig. 18.

[0151] In step S2301, the camera shutter shake correction control unit 230 acquires, from the tripod determination unit 226, determination information as to whether or not the camera 101 is currently in a static state.

[0152] Next, in step S2302, the camera shutter shake correction control unit 230 judges whether or not the camera 101 is in a static state from the judgment information acquired in step S2301. If the camera 101 is not in a static state, the camera shutter shake correction control unit 230 uses the IIS shutter shake correction amount previously determined in step S2303 as it is. Then, this process ends.

[0153] On the other hand, if the camera 101 is in a static state, the camera shutter shake correction control unit 230 performs processing to change the shutter shake correction amount in step S2304. This processing is the same as the processing performed in step S2105 in FIG. 21. Also, in this step, similar to step S1301 in FIG. 13, the camera shutter shake correction control unit 230 acquires the parallel decentering sensitivity of the OIS, which is lens information. Then, as described in FIGS. 11(a) and (b), a gain to be multiplied by the IIS shutter shake correction amount is selected according to the value of the parallel decentering sensitivity (optical characteristic). Then, this processing ends.

[0154] In this embodiment, the case has been described where the IIS shutter shake compensation amount is changed depending on whether the camera 101 is in a static state or not, but the IIS shutter shake compensation amount may also be changed depending on whether the interchangeable lens 110 is in a static state or not.

[0155] In this embodiment, the case where it is determined whether or not the camera 101 is in a static state is described, using the determination information from the tripod determination unit 226, but the determination information on the static state may be acquired by communicating with a tripod device that externally holds the camera 101. Also, an input device may be provided in the camera 101, and the camera may be determined to be in a static state by the user inputting the fact that the camera is in a static state through the input device.

[0156] The flowchart in FIG. 24 shows the process of obtaining (determining) the IIS shutter shake compensation amount used in step S2303 in FIG.

[0157] In step S2401, camera shutter shake correction control unit 230 determines whether or not the user has input an instruction to start obtaining an IIS shutter shake correction amount through operation unit 214. If the instruction has been input, camera shutter shake correction control unit 230 causes shutter 205 to run through camera control unit 215 in step S2402.

[0158] Next, in step S2403, the camera shutter shake correction control unit 230 detects the amount of shake that occurred during the movement of the shutter 205 in step S2402 through the camera shake detection unit 227, and calculates the drive amount of the image sensor 206 corresponding to the amount of shake as the IIS shutter shake correction amount. Then, the calculated IIS shutter shake correction amount is stored in the storage memory 213, and this process ends.

[0159] After carrying out this process, the camera shutter shake compensation control unit 230 reads out the IIS shutter shake compensation amount from the storage memory 213 and uses it in step S2303.

[0160] The IIS shutter shake compensation amount may be determined based on the amount of displacement of the image sensor 206 detected by the IIS position detection unit 228, or may be determined using another method. EXAMPLES

[0161] The flowchart in FIG. 25 shows the sensor lock process performed by the camera control unit 215 in the static state.

[0162] In step S2501, the camera control unit 215 acquires, from the tripod determination unit 226, determination information as to whether or not the camera 101 is currently in a static state.

[0163] Next, in step S2502, the camera control unit 215 determines whether or not the camera 101 is in a static state from the determination information acquired in step S2301. If the camera 101 is not in a static state, the camera control unit 215 causes the sensor lock unit 236 to fix the image sensor 206 at the reference position in step S2503. This makes it possible to suppress movement of the image sensor 206 caused by external vibrations including shutter shake.

[0164] In this embodiment, the image sensor 206 is fixed in a static state, but the correction lens 202 may be fixed in a reference position.

[0165] In each of the above embodiments, a case has been described in which an interchangeable lens 110 having an OIS is attached to the camera 101, but shutter shake correction using the IIS may also be performed when an interchangeable lens without an OIS is attached to the camera 101. In this case, shutter shake correction using the IIS is performed when the interchangeable lens (image capture optical system) has optical characteristics that move the subject image in the direction opposite to the direction of shutter shake when shutter shake occurs in the camera body due to driving of the shutter 205.

[0166] Furthermore, in each of the above embodiments, the case where shutter shake correction is performed by the IIS has been described, but shutter shake correction may be performed by the lens shutter shake correction control unit 256 described above under the control of the OIS.

[0167] The above embodiment includes the following configurations.

[0168] (Configuration 1) an imaging element that captures a subject image formed by an imaging optical system; a main body that holds the imaging optical system and movably holds the imaging element; a first vibration isolation means for moving the imaging element relative to the main body; a mechanical shutter fixed to the main body and controlling exposure of the image sensor; a control means for controlling the first driving means, The control means controlling the first vibration reduction means so as to reduce image blur caused by a first vibration detected regardless of driving of the mechanical shutter; an imaging device characterized in that, when the imaging optical system satisfies a predetermined condition, when a second shake occurs in the body due to driving of the mechanical shutter, the first vibration reduction means is controlled so as to reduce relative displacement between the body and the imaging element caused by the second shake. (Configuration 2) 2. The imaging device according to configuration 1, wherein the control means controls the first vibration isolation means to move the imaging element in the same direction as a shaking direction of the main body caused by the second shake. (Configuration 3) The imaging device described in configuration 1 or 2, characterized in that when the specified condition is satisfied, the control means controls the first vibration reduction means to reduce the relative displacement between the main body and the imaging element caused by the second shake when the imaging optical system has optical characteristics that move the subject image in a direction opposite to a direction of the second shake when a second shake occurs in the main body due to driving of the mechanical shutter. (Configuration 4) The image pickup device according to configuration 3, wherein the control means determines whether or not the image pickup optical system has the optical characteristic, and if it is determined that the image pickup optical system does not have the optical characteristic, does not control the first image stabilization means against the second shake, and if it is determined that the image pickup optical system has the optical characteristic, controls the first image stabilization means against the second shake. (Configuration 5) The imaging device described in configuration 3 or 4, wherein the control means changes the amount of drive of the imaging element by controlling the first vibration isolation means against the second shake in accordance with the optical characteristics when the imaging device is in a static state. (Configuration 6) In a case where the first vibration isolation means and a second vibration isolation means that moves a correction optical system included in the imaging optical system are controlled in response to the first vibration, The imaging device according to any one of configurations 3 to 5, wherein the control means controls the first vibration reduction means so as to reduce the relative displacement for the second shake when the correction optical system has the optical characteristic. (Configuration 7) In a case where the first and second vibration isolating means are controlled with respect to the first vibration at a ratio set therefor, The imaging device according to configuration 6, characterized in that, when controlling the first vibration isolation means for the second shake, the control means reduces a driving range of the imaging element by controlling the first vibration isolation means for the first shake compared to a case where the first vibration isolation means is not controlled for the second shake, and controls the first vibration isolation means for the first shake at a ratio according to the reduced driving range. (Configuration 8) The imaging device according to any one of configurations 1 to 7, characterized in that, when controlling the first vibration isolation means for the second shake, the control means narrows a driving range of the imaging element by controlling the first vibration isolation means for the first shake compared to a case in which the first vibration isolation means is not controlled for the second shake. (Configuration 9) 9. The imaging device according to any one of configurations 1 to 8, wherein the control means controls the first vibration isolation means against the second vibration when the shutter speed of the mechanical shutter is within a predetermined range. (Configuration 10) The imaging device according to any one of configurations 1 to 9, wherein the control means changes a driving range of the imaging element by controlling the first vibration compensation means against the first shake when the imaging element is not exposed to light, and changes a control characteristic of the first vibration compensation means, depending on whether or not to control the first vibration compensation means against the second shake. (Configuration 11) The focal length of the imaging optical system is variable, 11. The imaging device according to any one of configurations 1 to 10, wherein the control means changes a control characteristic of the first vibration isolation means for the second vibration in response to a change in the focal length. (Configuration 12) The imaging device described in configuration 11, characterized in that when the focal length is changed during exposure of the imaging element, the control means does not change the control characteristic when a change in the control characteristic with respect to the change in the focal length is greater than a predetermined value, and changes the control characteristic when a change in the control characteristic with respect to the change in the focal length is smaller than the predetermined value. (Configuration 13) The focal length of the imaging optical system is variable, In a case where the first vibration isolation means and a second vibration isolation means that moves a correction optical system included in the imaging optical system are controlled with respect to the second vibration, The imaging device according to any one of configurations 1 to 12, characterized in that the control means changes the amount of drive of the imaging element by control of the first vibration reduction means for the second shake in response to a change in the focal length so that the amount of drive of the correction optical system by control of the second vibration reduction means for the second shake is inversely proportional to the amount of drive of the correction optical system by control of the second vibration reduction means. (Configuration 14) The imaging device described in any one of configurations 1 to 13, characterized in that the control means changes the control characteristics of the first vibration isolation means for the second shake depending on whether the imaging device is in a static state or not. (Configuration 15) The control means Control data for the first vibration isolation means is stored, 15. The imaging device according to any one of configurations 1 to 14, wherein the first vibration isolation means is controlled using the control data when the mechanical shutter is driven. (Configuration 16) 16. The imaging apparatus according to configuration 15, wherein the control data is data acquired based on the second shake detected by driving the mechanical shutter. (Configuration 17) a fixing means for fixing the imaging element at a reference position; 17. The imaging device according to any one of configurations 1 to 16, wherein the control means causes the fixing means to fix the imaging element when the imaging device is in a static state. (Other Examples) The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0169] The embodiments described above are merely representative examples, and various modifications and alterations are possible for each embodiment when implementing the present invention. [Explanation of symbols]

[0170] 101 Digital Camera 110 Interchangeable Lenses 202 Corrective Lenses 205 Shutter 206 Image sensor 215 Camera control unit 220 Lens shake detector 221 OIS control unit 227 Camera shake detection unit 229 IIS Control Unit 240 Lens control unit

Claims

1. an imaging element that captures a subject image formed by an imaging optical system; a main body that holds the imaging optical system and movably holds the imaging element; a first vibration isolation means for moving the imaging element relative to the main body; a mechanical shutter fixed to the main body and controlling exposure of the image sensor; a control means for controlling the first driving means, The control means controlling the first vibration reduction means so as to reduce image blur caused by a first vibration detected regardless of driving of the mechanical shutter; an imaging device characterized in that, when the imaging optical system satisfies a predetermined condition, when a second shake occurs in the body due to driving of the mechanical shutter, the first vibration reduction means is controlled so as to reduce the relative displacement between the body and the imaging element caused by the second shake.

2. 2. The imaging apparatus according to claim 1, wherein the control means controls the first vibration isolation means to move the imaging element in the same direction as a shaking direction of the main body caused by the second shake.

3. The imaging device according to claim 1, characterized in that, when the specified condition is satisfied, the control means controls the first vibration reduction means to reduce the relative displacement between the body and the imaging element caused by the second shake when the imaging optical system has optical characteristics that move the subject image in a direction opposite to a direction of the second shake when a second shake occurs in the body due to driving of the mechanical shutter.

4. The imaging device according to claim 3, wherein the control means determines whether or not the imaging optical system has the optical characteristic, and if it is determined that the imaging optical system does not have the optical characteristic, does not control the first vibration isolation means against the second shake, and if it is determined that the imaging optical system has the optical characteristic, controls the first vibration isolation means against the second shake.

5. The imaging device according to claim 3 , characterized in that, when the imaging device is in a static state, the control means changes the amount of drive of the imaging element by controlling the first vibration reduction means against the second vibration in accordance with the optical characteristics.

6. In a case where the first vibration isolation unit and a second vibration isolation unit that moves a correction optical system included in the imaging optical system are controlled in response to the first vibration, 4. The imaging apparatus according to claim 3, wherein the control means controls the first vibration isolation means so as to reduce the relative displacement with respect to the second vibration when the correction optical system has the optical characteristic.

7. In a case where the first and second vibration isolating means are controlled with respect to the first vibration at a ratio set thereto, The imaging device according to claim 6, characterized in that, when controlling the first vibration-reduction means for the second shake, the control means reduces a driving range of the imaging element by controlling the first vibration-reduction means for the first shake compared to a case in which the first vibration-reduction means is not controlled for the second shake, and controls the first vibration-reduction means for the first shake at a ratio corresponding to the reduced driving range.

8. The imaging device according to claim 1, characterized in that, when controlling the first vibration reduction means for the second shake, the control means reduces a driving range of the imaging element by controlling the first vibration reduction means for the first shake compared to a case in which the control means does not control the first vibration reduction means for the second shake.

9. 2. The image pickup apparatus according to claim 1, wherein said control means controls said first vibration isolation means against said second vibration when the shutter speed of said mechanical shutter is within a predetermined range.

10. 2. The imaging device according to claim 1, wherein the control means changes a driving range of the imaging element by control of the first vibration compensation means against the first shake when the imaging element is not exposed to light, and changes a control characteristic of the first vibration compensation means, depending on whether or not to control the first vibration compensation means against the second shake.

11. The focal length of the imaging optical system is variable, 2. The image pickup apparatus according to claim 1, wherein the control means changes a control characteristic of the first vibration reduction means with respect to the second vibration in response to a change in the focal length.

12. 12. The imaging device according to claim 11, wherein, when the focal length is changed during exposure of the imaging element, the control means does not change the control characteristic when a change in the control characteristic with respect to the change in the focal length is greater than a predetermined value, and changes the control characteristic when a change in the control characteristic with respect to the change in the focal length is smaller than the predetermined value.

13. The focal length of the imaging optical system is variable, In a case where the first vibration isolation means and a second vibration isolation means that moves a correction optical system included in the imaging optical system are controlled with respect to the second vibration, 2. The imaging device according to claim 1, wherein the control means changes the amount of drive of the image sensor under control of the first vibration reduction means for the second shake in response to the change in focal length so that the amount of drive of the correction optical system under control of the second vibration reduction means for the second shake is inversely proportional to the amount of drive of the correction optical system under control of the second vibration reduction means for the second shake.

14. 2. The image pickup apparatus according to claim 1, wherein the control means changes a control characteristic of the first vibration isolation means with respect to the second vibration depending on whether the image pickup apparatus is in a static state or not.

15. The control means Control data for the first vibration isolation means is stored, 2. The image pickup apparatus according to claim 1, wherein the first vibration isolation means is controlled using the control data when the mechanical shutter is driven.

16. 16. The image pickup apparatus according to claim 15, wherein the control data is data acquired based on the second shake detected by driving the mechanical shutter.

17. a fixing means for fixing the imaging element at a reference position; 2. The image pickup apparatus according to claim 1, wherein the control means causes the fixing means to fix the image pickup element when the image pickup apparatus is in a static state.

18. A method for controlling an imaging device having an imaging element that captures a subject image formed by an imaging optical system, a main body that holds the imaging optical system and movably holds the imaging element, a first vibration isolation means that moves the imaging element relative to the main body, and a mechanical shutter that is fixed to the main body and controls exposure of the imaging element, comprising: controlling the first vibration reduction means so as to reduce image blur caused by a first vibration detected regardless of driving of the mechanical shutter; A control method characterized by controlling the first vibration reduction means so as to reduce the relative displacement between the main body and the imaging element caused by a second shake when the imaging optical system satisfies a predetermined condition and a second shake occurs in the main body due to driving of the mechanical shutter.

19. A program for causing a computer of the imaging device to execute a process according to the control method of claim 18.

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