Image stabilization device, interchangeable lens, camera system, and camera body

Abstract

To properly suppress blurs when located at other than the center of an image surface that intersects the optical axis.SOLUTION: Provided is a blur correction device equipped with a blur correction element capable of moving in a plane that intersects the optical axis, said device comprising a motion detection unit for detecting the motion of an apparatus equipped with the blur correction device, an input unit to which information indicating the position on an image surface of an imaging element that captures a subject image is inputted, and a drive unit for moving the blur correction element. On the basis of the motion of a rotational direction component around an axis X out of said motion, the drive unit moves the blur correction element to a different position in the direction of an axis Y that intersects the axis X and does not move the blur correction element to a different position in the direction of the axis X when the position is apart by a first distance from the optical axis of an optical system, and moves the blur correction element to a different position in the direction of the axis Y and moves the blur correction element to a different position in the direction of the axis X when the position is apart by a second distance greater than the first distance from the optical axis of the optical system.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vibration reduction device. , interchangeable lenses, camera systems, and camera bodies Regarding. [Background technology]

[0002] There is a known technique for suppressing image blur caused by camera shake (see Patent Document 1). However, this technique only corrects image blur in the center of the screen. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-235806 Summary of the Invention

[0004] According to a first aspect, a blur correction device includes: a detection unit that detects movement; a first correction element that moves in a direction intersecting an optical axis of an optical system that forms an image of a subject, based on the movement detected by the detection unit; When correcting an image blur at a position that is farther away from the center of the image than a predetermined distance, When the detection unit detects rotation around the X axis, Depending on the position on the image plane where image blur is to be corrected, The Y-axis component perpendicular to the X-axis and before X-axis direction component and and moving the first corrective element in a direction having the and moving the first correcting element in the Y-axis direction. a first control unit; When the first control unit moves the first correction element in a direction having the Y-axis direction component, the further a position on the image plane where image blur is corrected is from the center of the image, the longer the length of movement of the first correction element. . According to a second aspect, an interchangeable lens includes the image stabilization device according to the first aspect. According to a third aspect, a camera system includes the interchangeable lens according to the first aspect and a camera body. According to a fourth aspect, a camera body includes the image stabilization device according to the first aspect. [Brief explanation of the drawings]

[0005] [Figure 1] 1 is a diagram showing the configuration of a main part of a camera according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating a shake correction unit. [Figure 3] 5A and 5B are schematic diagrams illustrating the detection direction of angular velocity and image blur on the image plane. [Figure 4] 4A to 4C are diagrams illustrating the image blur in FIG. 3. [Figure 5] FIG. 10 is a diagram illustrating an example of a focus area formed on an imaging screen. [Figure 6] FIG. 10 is a diagram illustrating an example of determining one representative position from a plurality of candidates. [Figure 7] FIG. 10 is a diagram illustrating a second modified example of the first embodiment. [Figure 8] 5A and 5B are schematic diagrams illustrating the detection direction of angular velocity and image blur on the image plane. [Figure 9] FIG. 10 is a diagram illustrating an example in which distortion occurs. [Figure 10] FIG. 10 is a diagram showing the main configuration of a camera according to a third embodiment. [Figure 11] FIG. 2 is a diagram illustrating a shake correction unit of an interchangeable lens. DETAILED DESCRIPTION OF THE INVENTION

[0006] (First embodiment) An imaging device equipped with an image stabilization device according to a first embodiment will be described with reference to the drawings. An interchangeable lens digital camera (hereinafter referred to as camera 1) will be shown as an example of the imaging device, but camera 1 may be a single-lens reflex type equipped with a mirror 24 on a camera body 2, or a mirrorless type not equipped with a mirror 24. Furthermore, the camera 1 may be configured as an integrated lens type in which the interchangeable lens 3 and the camera body 2 are integrated into one body. Furthermore, the imaging device is not limited to the camera 1, but may be a lens barrel equipped with an imaging sensor, a smartphone equipped with an imaging function, or the like.

[0007] <Main components of the camera> FIG. 1 is a diagram showing the essential configuration of a camera 1. The camera 1 is made up of a camera body 2 and an interchangeable lens 3. The interchangeable lens 3 is attached to the camera body 2 via a mount (not shown). When the interchangeable lens 3 is attached to the camera body 2, the camera body 2 and the interchangeable lens 3 are electrically connected, enabling communication between the camera body 2 and the interchangeable lens 3. Note that communication between the camera body 2 and the interchangeable lens 3 may also be performed via wireless communication.

[0008] In Figure 1, light from the subject is incident in the negative direction of the Z axis. As shown on the coordinate axes, the direction toward the front of the paper, perpendicular to the Z axis, is the positive X axis, and the upward direction, perpendicular to the Z and X axes, is the positive Y axis. In the following figures, the coordinate axes in Figure 1 will be used as the reference, and the coordinate axes will be displayed so that the orientation of each figure can be understood.

[0009] <Interchangeable lenses> The interchangeable lens 3 has an imaging optical system (imaging optical system) and forms a subject image on the imaging surface of the image sensor 22 provided in the camera body 2. The imaging optical system includes a zoom optical system 31, a focus (focus adjustment) optical system 32, a shake correction optical system 33, and an aperture 34. The interchangeable lens 3 further has a zoom drive mechanism 35, a focus drive mechanism 36, a shake correction drive mechanism 37, an aperture drive mechanism 38, and a shake sensor (motion detection unit, shake detection unit) 39.

[0010] The zoom drive mechanism 35 adjusts the magnification of the imaging optical system by moving the zoom optical system 31 forward or backward in the direction of the optical axis L1 based on a signal output from the CPU 21 of the camera body 2. The signal output from the CPU 21 includes information indicating the direction, amount, and speed of movement of the zoom optical system 31.

[0011] The focus drive mechanism 36 adjusts the focus of the imaging optical system by moving the focus optical system 32 forward and backward in the direction of the optical axis L1 based on a signal output from the CPU 21 of the camera body 2. The signal output from the CPU 21 during focus adjustment includes information indicating the direction, amount, and speed of movement of the focus optical system 32. The diaphragm driving mechanism 38 controls the aperture diameter of the diaphragm 34 based on a signal output from the CPU 21 of the camera body 2 .

[0012] The image stabilization drive mechanism 37 suppresses image blur by moving the image stabilization optical system 33 back and forth in a direction that cancels out blur of the subject image (referred to as image blur) on the imaging surface of the imaging element 22 within a plane that intersects with the optical axis L1, based on a signal output from the CPU 21 in the camera body 2. The signal output from the CPU 21 includes information that indicates the direction, amount, and speed of movement of the image stabilization optical system 33.

[0013] The shake sensor 39 detects the shake of the camera 1 when the camera 1 is shaken due to hand shake or the like. The shake sensor 39 is made up of an angular velocity sensor 39a and an acceleration sensor 39b. It is assumed that the image shake is caused by the shake of the camera 1.

[0014] Angular velocity sensor 39a detects angular velocity generated by the rotational movement of camera 1. Angular velocity sensor 39a detects rotation around each of axes, for example, an axis parallel to the X axis, an axis parallel to the Y axis, and an axis parallel to the Z axis, and sends detection signals to CPU 21 of camera body 2. Angular velocity sensor 39a is also called a gyro sensor.

[0015] Additionally, acceleration sensor 39b detects acceleration generated by translational motion of camera 1. Acceleration sensor 39b detects acceleration in the directions of axes parallel to the X-axis, Y-axis, and Z-axis, for example, and sends detection signals to CPU 21 of camera body 2. Acceleration sensor 39b is also called a G sensor. In this example, the shake sensor 39 is provided in the interchangeable lens 3, but the shake sensor 39 may also be provided in the camera body 2. Also, the shake sensor 39 may be provided in both the camera body 2 and the interchangeable lens 3.

[0016] <Camera body> The camera body 2 includes a CPU 21, an image sensor 22, a shutter 23, a mirror 24, an AF sensor 25, a shake correction drive mechanism 26, a signal processing circuit 27, a memory 28, an operation member 29, and a liquid crystal display unit 30.

[0017] The CPU 21 is configured with a CPU, a RAM (Random Access Memory), a ROM (Read Only Memory), etc., and controls each part of the camera 1 based on a control program. The CPU 21 includes a shake correction part (correction amount calculation part) 21a.

[0018] The shake correction unit 21a calculates image blur caused by the rotational movement of the camera 1 and the translational movement of the camera 1. Based on the calculation results by the shake correction unit 21a, the CPU 21 moves the shake correction optical system 33 using the shake correction drive mechanism (shake correction drive unit) 37, and moves the image sensor 22 using the shake correction drive mechanism (shake correction drive unit) 26.

[0019] In the first embodiment, image blur is suppressed by moving the image sensor 22 or the image blur correction optical system 33 of the interchangeable lens 3 that constitutes the imaging optical system. This suppression of image blur is also called image blur correction. Details of image blur correction will be described later.

[0020] The image sensor 22 in Fig. 1 is configured by a CCD image sensor or a CMOS image sensor. The image sensor 22 receives a light beam that has passed through an imaging optical system on its imaging surface and performs photoelectric conversion (captures) an image of a subject. Through photoelectric conversion, charges are generated in each of the multiple pixels arranged on the imaging surface of the image sensor 22 according to the amount of received light. A signal based on the generated charges is read out from the image sensor 22 and sent to a signal processing circuit 27.

[0021] The shutter 23 controls the exposure time of the image sensor 22. The exposure time of the image sensor 22 can also be controlled by a method of controlling the charge accumulation time in the image sensor 22 (so-called electronic shutter control). The shutter 23 is driven to open and close by a shutter drive unit (not shown).

[0022] A semi-transparent quick-return mirror (hereinafter referred to as "mirror") 24 is driven by a mirror driver (not shown) to move between a down position (illustrated in FIG. 1) where the mirror 24 is on the optical path and an up position where the mirror 24 is retracted from the optical path. For example, before the shutter is released, the mirror 24 is in the down position and reflects subject light upward (in the positive direction of the Y axis) toward a viewfinder (not shown) located above. Furthermore, a portion of the subject light that passes through the mirror 24 is bent downward (in the negative direction of the Y axis) by a sub-mirror 24a and directed to the AF sensor 25. Immediately after the release switch is pressed, the mirror 24 is rotated to the up position, whereby subject light is guided to the image sensor 22 via the shutter 23.

[0023] The AF sensor 25 detects the focus adjustment state of the imaging optical system of the interchangeable lens 3. The CPU 21 performs a focus detection calculation using a known phase difference method using a detection signal from the AF sensor 25. The CPU 21 determines the amount of defocus by the imaging optical system through this calculation, and calculates the amount of movement of the focus optical system 32 based on the amount of defocus. The CPU 21 transmits the calculated amount of movement of the focus optical system 32 to the focus drive mechanism 36, along with the direction and speed of movement.

[0024] Based on a signal output from CPU 21, blur correction drive mechanism 26 moves image sensor 22 back and forth in a direction that cancels out image blur within a plane intersecting optical axis L1, thereby suppressing image blur on the imaging surface of image sensor 22. The signal output from CPU 21 includes information indicating the direction, amount, and speed of movement of image sensor 22.

[0025] The signal processing circuit 27 generates image data relating to the subject image based on the image signal read from the image sensor 22. The signal processing circuit 27 also performs predetermined image processing on the generated image data. The image processing includes, for example, well-known image processing such as tone conversion processing, color interpolation processing, edge enhancement processing, and white balance processing.

[0026] The memory 28 is configured by, for example, an EEPROM (Electrically Erasable Programmable Read Only Memory), a flash memory, etc. The memory 28 records, for example, adjustment value information such as the detection gain to be set in the shake sensor 39. The CPU 21 records data in the memory 28 and reads data from the memory 28.

[0027] The operation members 29 include a release button, a recording button, a live view button, various setting switches, etc., and output operation signals to the CPU 21 according to the respective operations. In response to instructions from the CPU 21, the liquid crystal display unit 30 displays an image based on image data, information relating to photography such as shutter speed and aperture value, and a menu operation screen.

[0028] The recording medium 50 is configured, for example, by a memory card or the like that is detachable from the camera body 2. Image data, audio data, etc. are recorded on the recording medium 50. The recording of data on the recording medium 50 and the reading of data from the recording medium 50 are performed by the CPU 21.

[0029] <Image stabilization> Camera 1 according to the first embodiment is configured to be able to perform image blur correction by operating blur correction drive mechanism 37 of interchangeable lens 3, and by operating blur correction drive mechanism 26 of camera body 2. In the first embodiment, CPU 21 operates one of the blur correction drive mechanisms. For example, when interchangeable lens 3 equipped with blur correction drive mechanism 37 is attached to camera body 2, CPU 21 operates blur correction drive mechanism 37 of interchangeable lens 3 to perform image blur correction, and when interchangeable lens 3 not equipped with blur correction drive mechanism 37 is attached to camera body 2, CPU 21 operates blur correction drive mechanism 26 of camera body 2 to perform image blur correction. As in a third embodiment described later, the shake correction drive mechanisms of the interchangeable lens 3 and the camera body 2 may be operated simultaneously.

[0030] In general, image blur occurring in camera 1 can be divided into image blur (also called angular blur) caused by the rotational movement of camera 1 and image blur (also called translational blur) caused by the translational movement of camera 1. Shake correction unit 21a calculates image blur caused by the rotational movement of camera 1 and image blur caused by the translational movement of camera 1, respectively.

[0031] 2 is a diagram illustrating the shake correction unit 21a. The shake correction unit 21a has an angular shake calculation unit 201, a translational shake calculation unit 202, and a shake correction optical system target position calculation unit (selection unit) 203. The angular shake calculation unit 201 calculates image blur in the Y-axis direction due to rotational movement using a detection signal from the angular velocity sensor 39a about an axis parallel to the X-axis (pitch direction).The angular shake calculation unit 201 also calculates image blur in the X-axis direction due to rotational movement using a detection signal from the angular velocity sensor 39a about an axis parallel to the Y-axis (yaw direction).

[0032] The translational shake calculation unit 202 calculates the image blur in the X-axis direction caused by translational motion using the detection signal in the X-axis direction by the acceleration sensor 39b. Also, the translational shake calculation unit 202 calculates the image blur in the Y-axis direction caused by translational motion using the detection signal in the Y-axis direction by the acceleration sensor 39b.

[0033] The image blur correction optical system target position calculation unit 203 calculates the image blur in the X-axis and Y-axis directions by adding, for each axis, the image blur in the X-axis and Y-axis directions calculated by the angular shake calculation unit 201 and the image blur in the X-axis and Y-axis directions calculated by the translational shake calculation unit 202. For example, if the image blur calculated by the angular shake calculation unit 201 and the image blur calculated by the translational shake calculation unit 202 in a certain axial direction have the same direction, the image blur will increase as a result of the addition, but if the directions of the two calculated image blurs are different, the image blur will decrease as a result of the addition. In this way, the addition calculation is performed by assigning a positive or negative sign depending on the direction of the image blur in each axis.

[0034] Next, the image blur correction optical system target position calculation unit 203 calculates the amount of image blur at a predetermined position on the image plane (the imaging plane of the image sensor 22) based on the image blur in the X-axis direction and the Y-axis direction after the sum, the shooting magnification (calculated based on the position of the zoom optical system 31), and the distance from the camera 1 to the subject 80 (calculated based on the position of the focus optical system 32).

[0035] When image blur correction is performed by operating the image blur correction drive mechanism 37 of the interchangeable lens 3, the image blur correction optical system target position calculation unit 203 calculates a target position of the image blur correction optical system 33 for moving the image blur correction optical system 33 in a direction that cancels out the calculated amount of image blur. Furthermore, when image blur correction is performed by operating the image blur correction drive mechanism 26 of the camera body 2, the image blur correction optical system target position calculation unit 203 calculates a target position of the image sensor 22 for moving the image sensor 22 in a direction that cancels out the calculated amount of image blur.

[0036] Then, blur correction optical system target position calculation section 203 sends a signal indicating the target position to blur correction drive mechanism 37 of interchangeable lens 3 or blur correction drive mechanism 26 of camera body 2 . It should be noted that the image stabilization optical system target position calculation unit 203 can also send signals indicating target positions to the interchangeable lens 3 and the image stabilization drive mechanism of the camera body 2 . Furthermore, if the target position transmitted from camera body 2 exceeds the movable range of image stabilization drive mechanism 37, image stabilization drive mechanism 37 of interchangeable lens 3 may notify CPU 21 of camera body 2 of this fact. This enables CPU 21 to take appropriate measures, such as issuing an alarm to notify that the allowable range of image stabilization has been exceeded.

[0037] <Image blur at a predetermined position> The calculation of image blur by angular blur calculation unit 201 will be described in more detail below. In the first embodiment, when angular blur calculation unit 201 calculates image blur caused by the rotational movement of camera 1, it determines a position on the image plane (imaging plane of image sensor 22) in advance and calculates image blur for this position. The reason for doing so is that image blur differs depending on the position on the image plane even if the rotation angle of the rotational movement is the same.

[0038] FIG. 3 is a schematic diagram illustrating the direction in which angular velocity is detected by the angular velocity sensor 39a and image blur on the image plane 70 (the imaging plane of the image sensor 22). In FIG. 3, the origin of the coordinate system is the point where the image plane 70 intersects with the optical axis L1 of the interchangeable lens 3, the optical axis L1 of the interchangeable lens 3 is the Z axis, and the image plane 70 is represented as an XY plane. According to FIG. 3, the optical axis L1 intersects with the center of the imaging plane. The interchangeable lens 3 and the subject 80 are located in the positive direction of the Z axis relative to the image plane 70. The angular velocity sensor 39a detects, for example, a rotation angle θ (pitch direction) around an axis (small-x axis) parallel to the X axis. When the subject 80 is located far away, the symbol f in FIGS. 3 and 4 represents the focal length.

[0039] When camera 1 shakes, the image of subject 80, which was located at coordinates (0, yp) on image plane 70 before the shake, moves in the negative Y-axis direction after the shake. The position of the image of subject 80 that has moved is now at coordinates (0, yp-Δy2). Figure 4 is a diagram for explaining the image blur Δy2 in Figure 3, and shows the YZ plane in Figure 3.

[0040] The image blur Δy2 can be expressed by the following equation (1). Δy2=f×tan(θ+tan -1 (yp / f))-yp …(1) Here, the rotation angle in the pitch direction (representing the camera shake angle, generally about 0.5 degrees) is θ. When the subject 80 is far away, the symbol f in Figures 3 and 4 represents the focal length of the interchangeable lens 3.

[0041] For comparison with the above equation (1), we will explain the image blur Δy1 of the image of subject 80 that was located at coordinates (0,0) in the center of image plane 70 before camera 1 was shaken. The rotation angle in the pitch direction of interchangeable lens 3 is assumed to be the same θ as above. When camera 1 is shaken, the image of subject 80 that was located at coordinates (0,0) on image plane 70 before the shake moves in the negative Y-axis direction after the shake. The position of the image of subject 80 that has moved is coordinates (0,-Δy1).

[0042] The image blur Δy1 can be expressed by the following equation (2). Δy1=f×tanθ …(2) According to the above equations (1) and (2), when the focal length f is sufficiently large compared to yp, the rotation angle θ (camera shake angle) is generally about 0.5 degrees, so Δy1 can be considered to be approximately Δy2. That is, whether the position of the image of the subject 80 on the image plane 70 is at the center of the image plane 70 (the origin in this example) or at a position away from the center, in other words, regardless of the distance from the optical axis L1, the image blur can be considered to be approximately the same. This means that the position on the image plane 70 can be determined anywhere to calculate the image blur. Therefore, for example, if image blur correction is performed based on image blur calculated at the center of the image plane 70, image blur can be suppressed for both the image of the subject 80 located at the center of the image plane 70 and the image of the subject 80 located away from the center of the image plane 70.

[0043] However, when the focal length f is not sufficiently larger than yp, such as when the interchangeable lens 3 is a wide-angle lens, Δy1<Δy2. Therefore, it is necessary to calculate image blur by determining a position on the image plane 70. For example, if image blur correction is performed based on image blur calculated at the center of the image plane 70, image blur of the image of the subject 80 located at the center of the image plane 70 can be suppressed, but image blur equivalent to the difference between Δy2 and Δy1 cannot be suppressed and remains for images of the subject 80 located away from the center of the image plane 70. The difference between Δy2 and Δy1 becomes larger as the position for calculating image blur moves closer to the periphery of the image plane 70, i.e., as the image height increases.

[0044] <Position for calculating image blur> In many cases, users desire to suppress image blur of the image of a main subject among subjects 80 to be captured. Therefore, as will be described later, CPU 21 in the first embodiment determines a position on image plane 70 where the image of the main subject is likely to exist. Then, angular blur calculation unit 201 calculates image blur at the position determined by CPU 21 and performs image blur correction based on this image blur. The CPU 21 selects one of the following methods (1) to (3) to determine the position for calculating image blur. After determining the position for calculating image blur, if the CPU 21 detects the amount of movement of the camera 1 due to a change in composition, for example, the CPU 21 resets (updates) the position for calculating image blur. The vibration sensor 39 also functions as a movement amount detection unit.

[0045] (1) Focus area position The first method is to calculate the image blur at the position of the focus area. Fig. 5 is a diagram illustrating an example of focus areas formed on an imaging screen 90. A focus area is an area where the AF sensor 25 detects the focus adjustment state, and is also called a focus detection area, a distance measurement point, or an autofocus (AF) point. In the first embodiment, eleven focus areas 25P-1 to 25P-11 are provided in advance on the imaging screen 90. The CPU 21 can calculate the defocus amount in each of the eleven focus areas. The number of focus areas 25P-1 to 25P-11 is just an example, and may be more or less than 11.

[0046] The CPU 21 determines the position on the image plane 70 where image blur is calculated to be a position corresponding to the selected focus area. The angular blur calculation unit 201 then calculates the image blur at the position determined by the CPU 21 and performs image blur correction based on this image blur. The reason why the position on the image plane 70 where image blur is calculated is determined to be a position corresponding to the selected focus area is that there is a high possibility that the main subject is located at the position where the defocus amount for focus adjustment is to be calculated. The focus area may be selected by CPU 21 based on an operation signal from operation member 29, or may be selected by CPU 21 based on a focus area corresponding to subject 80 close to camera 1. CPU 21 can select a focus area corresponding to subject 80 close to camera 1, for example, based on the position of focus optical system 32. CPU 21 may also select a focus area corresponding to subject 80 with high contrast among images of subject 80, or may select a focus area corresponding to subject 80 with a high brightness value among images of subject 80.

[0047] (2) Subject position The second method is to calculate image blur at the position of an object (subject 80) that appears in the image. For example, the CPU 21 recognizes the object that appears in the live view image as the subject 80 using a known object recognition process, and determines the position of the object (subject 80) in the live view image as the position of the main subject. Then, the position on the image plane 70 where image blur is to be calculated is determined to be a position corresponding to the main subject. The angular blur calculation unit 201 calculates image blur at the position determined by the CPU 21, and performs image blur correction based on this image blur.

[0048] A live view image is a monitor image acquired by the image sensor 22 at a predetermined interval (e.g., 60 fps) before actual imaging is performed. For example, when a live view button constituting the operation member 29 is operated, the CPU 21 keeps the mirror 24 rotated to the up position and causes the image sensor 22 to start acquiring a live view image. The CPU 21 can also display the live view image on the liquid crystal display unit 30.

[0049] CPU 21 can also track a moving object (subject 80) by, for example, successively updating the position of the main subject based on each frame of a live view image. In this case, angular shake calculation unit 201 successively calculates image shake at the position successively updated by CPU 21, thereby performing image shake correction for the moving object (subject 80) when acquiring a live view image. Furthermore, even when the camera 1 is panned, the CPU 21 can track a moving object (subject 80) by successively updating the position of the main subject in each frame of the live view image.

[0050] For example, when the camera 1 is set to an imaging scene mode such as "landscape," "food," "flowers," or "animals," the CPU 21 may select the second method and start the object recognition process. Also, the target for object recognition may be switched depending on the imaging scene mode set in the camera 1, such as "landscape," "food," "flowers," or "animals."

[0051] (3) Face position The third method is to calculate image blur at the position of a face (subject 80) that appears in the image. For example, the CPU 21 recognizes a face that appears as subject 80 in a live view image using known face recognition processing, and determines the position of the face in the live view image as the position of the main subject. Then, the position on the image plane 70 where image blur is to be calculated is determined to be a position corresponding to the main subject. The angular blur calculation unit 201 calculates image blur at the position determined by the CPU 21, and performs image blur correction based on this image blur.

[0052] For example, when a live view button constituting the operation member 29 is operated, the CPU 21 keeps the mirror 24 rotated to the up position and causes the image sensor 22 to start capturing a live view image.

[0053] As in (2) above, CPU 21 can also track a moving face (subject 80) by successively updating the position of the main subject based on each frame of the live view image. Angular shake calculation unit 201 performs image blur correction on the moving face (subject 80) when acquiring a live view image by successively calculating the image blur at the position successively updated by CPU 21.

[0054] For example, when the imaging scene mode of the camera 1 is set to "portrait", the CPU 21 may select the third method and start face recognition processing.

[0055] <When there are multiple positions for calculating image blur> The above methods (1) to (3) all illustrate the case where only one position on the image plane 70 is determined as the position for calculating image blur. However, there are cases where multiple positions are candidates for the position for calculating image blur, as described below. Specific examples include the case where multiple focus areas are selected in the above method (1), or the case where multiple objects (subjects 80) are recognized in the above method (2), or the case where multiple faces are recognized in the above method (3). In such cases, the CPU 21 selects the following method (4) or (5).

[0056] (4) Determine one representative position The fourth method is a method for calculating image blur at one representative position. FIG. 6 is a diagram illustrating an example of determining one representative position from multiple candidates. For example, if three points are candidates on the image plane 70, namely, position P-1 corresponding to focus area 25P-1 in FIG. 5, position P-2 corresponding to focus area 25P-2, and position P-4 corresponding to focus area 25P-4, the CPU 21 determines an average position P based on the absolute values ​​of the distances between the positions of the multiple candidates and the X axis (FIG. 3) and the absolute values ​​of the distances between the positions of the multiple candidates and the Y axis (FIG. 3), and determines position P as the representative position. Then, the position on the image plane 70 where image blur is calculated is determined as the representative position P. In this way, the representative position P is determined by averaging the absolute values ​​of the distances on the axes (X axis, Y axis) of the image plane 70.

[0057] The angular blur calculation unit 201 calculates the image blur at the representative position P and performs image blur correction based on this image blur.

[0058] In the above explanation of (4), a case where multiple focus areas are selected is exemplified, but the same applies when multiple objects (subjects 80) or multiple faces are recognized. For example, the CPU 21 determines the representative position P as described above based on the positions of the multiple recognized objects or the positions of the multiple recognized faces. The angular shake calculation unit 201 calculates image blur for the representative position P determined by the CPU 21, and performs image blur correction based on this image blur.

[0059] (5) Find one image blur 6, for example, three points on the image plane 70 are candidates: position P-1 corresponding to focus area 25P-1 in FIG. 5, position P-2 corresponding to focus area 25P-2, and position P-4 corresponding to focus area 25P-4.

[0060] The CPU 21 determines a plurality of positions as positions for calculating image blur on the image plane 70. The angular blur calculation unit 201 calculates image blur at each of positions P-1, P-2, and P-4 on the image plane 70. The angular blur calculation unit 201 further calculates the average of the calculated image blurs and performs image blur correction based on the average image blur value. The average value of the image blur is calculated by, for example, a simple average, but may also be calculated by a weighted average.

[0061] In the above explanation of (5), a case where multiple focus areas are selected is exemplified, but the same applies when multiple objects (subjects 80) or multiple faces are recognized. For example, the CPU 21 determines the positions of the multiple recognized objects or the positions of the multiple recognized faces as positions on the image plane 70 where image blur is calculated. The angular shake calculation unit 201 calculates image blur for each position on the image plane 70. The angular shake calculation unit 201 further calculates the average of the multiple calculated image blurs and performs image blur correction based on the average image blur value. As a variation of (4), one subject may be selected from multiple subjects. For example, a subject with significant image blur may be selected from multiple subjects. Alternatively, a subject with significant image blur that is close to the camera 1 may be selected from multiple subjects. Alternatively, a subject with a high image height from the optical axis L1 of the interchangeable lens 3 may be selected from multiple subjects.

[0062] Note that the image blur correction in the first embodiment includes correction in the Y-axis direction when the camera 1 rotates in the Pitch direction, and correction in the X-axis direction when the camera 1 rotates in the Yaw direction. The above description of the first embodiment has representatively explained correction in the Y-axis direction when the camera 1 is rotated in the pitch direction. When the camera 1 is also rotated in the yaw direction, correction similar to the correction described above is required for the X-axis direction. Correction in the Y-axis direction when the camera 1 is rotated in the pitch direction and correction in the X-axis direction when the camera 1 is rotated in the yaw direction are the same except for the direction, so explanation of correction in the X-axis direction will be omitted.

[0063] In the first embodiment, the image blur calculated by the translational blur calculator 202 is treated as being approximately constant even if the position on the image plane 70 (the imaging plane of the image sensor 22) varies. The outline of the first embodiment is as follows. The angular blur calculation unit 201 determines the position for calculating the image blur to be any position on the image plane 70 and calculates the image blur. The translational blur calculation unit 202 calculates the image blur by determining the position for calculating the image blur at, for example, the center of the image plane 70. The image blur correction optical system target position calculation unit 203 performs an addition calculation on the image blur calculated by the angular blur calculation unit 201 and the image blur calculated by the translational blur calculation unit 202, assigning a positive or negative sign depending on the direction of each of the X and Y axes, and then calculates the amount of image blur at the position of the image plane 70 based on the image blur in the X and Y axes after addition.

[0064] According to the first embodiment described above, the following advantageous effects can be obtained. (1) The image stabilization device of the camera 1 includes a shake sensor 39 that detects shake of the camera 1, a shake stabilization unit 21a that calculates the amount of shake of the image of the subject 80 formed on the image plane 70 by the imaging optical system based on the output of the shake sensor 39, and a CPU 21 that determines a position on the image plane 70. The shake stabilization unit 21a calculates image shake Δy2 in the Y-axis direction based on the position determined by the CPU 21 and the shake detected by the shake sensor 39, for example, in the Y-axis direction. This allows image shake to be appropriately suppressed even when the position of the image plane 70 determined by the CPU 21 is not the center of the image plane 70 intersecting with the optical axis L1. This is particularly suitable when the focal length f of the interchangeable lens 3 is short (or when the angle of view is wide due to the relationship between the size of the image sensor 22 and the focal length f).

[0065] (2) In the image stabilization device described in (1) above, the image stabilization unit 21a calculates a larger amount of blur as the distance from the X-axis direction axis intersecting the Y-axis direction to the determined position on the image plane 70 increases, so that image blur can be appropriately suppressed even at positions with a high image height.

[0066] (3) In the image stabilization device described in (2) above, the image stabilization unit 21a calculates the amount of blur based on the output of the shake sensor 39, the distance, and the focal length of the imaging optical system. Therefore, even if the interchangeable lens 3 is replaced with one having a different focal length f, image blur can be appropriately suppressed.

[0067] (4) In the image stabilization devices described above in (1) to (3), the CPU 21 determines the position of the focus area on the image plane 70 that is the target of focus adjustment of the imaging optical system as the determined position, thereby making it possible to appropriately suppress image blur at a position where the main subject is likely to be present.

[0068] (5) In the image stabilization device described above in (1) to (3), the CPU 21 determines the determined position based on contrast information of the subject image, so that image blur can be appropriately suppressed at a position where the main subject is likely to be present.

[0069] (6) In the image stabilization devices described above in (1) to (3), the CPU 21 determines the determined position based on the brightness value information of the image of the subject 80, so that image blur can be appropriately suppressed at a position where the main subject is likely to be present.

[0070] (7) In the image stabilization devices described above in (1) to (3), the CPU 21 determines the determined position based on subject recognition information based on the image of the subject 80, so that image blur can be appropriately suppressed at a position where the main subject is likely to be present.

[0071] (8) In the image stabilization devices described above in (1) to (3), the CPU 21 determines the determined position based on face recognition information based on the image of the subject 80, so that image blur can be appropriately suppressed at a position where the main subject is likely to be present.

[0072] (9) In the image stabilization devices described in (4) to (8) above, the CPU 21 determines the determined position based on the set imaging scene mode, so that image blur can be appropriately suppressed at a position where the main subject is likely to be present.

[0073] (10) In the image stabilization device described in (1) to (3) above, the CPU 21 determines the position on the image plane 70 designated by a user operation as the determined position, so that image blur can be appropriately suppressed at the position desired by the user.

[0074] (11) In the image stabilization devices described in (1) to (3) above, the CPU 21 determines the determined position to be, for example, a position corresponding to the subject 80 closest to the camera 1 based on shooting distance information, so that image blur can be appropriately suppressed at the position corresponding to the main subject.

[0075] (12) The image stabilization device described in (1) to (3) above includes a CPU 21 that detects the amount of movement due to a change in composition based on the output of the shake sensor 39. When the amount of movement is detected by the CPU 21 after the determined position is determined by the CPU 21, the image stabilization unit 21b calculates the amount of blur based on the position to which the determined position is changed based on the amount of movement. This makes it possible to appropriately suppress image blur at a position where the main subject is likely to be present after the composition change.

[0076] (13) In the image stabilization device of (4) above, when there are multiple focus areas that are the subject of focus adjustment of the imaging optical system, the CPU 21 determines the determined position as the center of gravity (representative position P) of the absolute values ​​of the distances on the axes (X-axis, Y-axis) of the image plane 70 based on the positions of the multiple focus areas, so that image blur can be appropriately suppressed so that the image blur at the positions of the multiple focus areas is the same.

[0077] (14) In the image stabilization device of (7) above, when there are multiple subjects according to the subject recognition information, the CPU 21 determines the center of gravity (representative position P) of the absolute values ​​of the distances on the axes (X-axis, Y-axis) of the image plane 70 as the determined position based on the positions of the multiple subjects, so that image blur can be appropriately suppressed so that the image blur at the positions of the multiple subjects is the same.

[0078] (15) In the image stabilization device of (8) above, when multiple faces are present according to the facial recognition information, the CPU 21 determines the determined position as the center of gravity (representative position P) of the absolute values ​​of the distances on the axes (X-axis, Y-axis) of the image plane 70 based on the positions of the multiple faces. This allows image blur to be appropriately suppressed so that the image blur at the positions of the multiple faces is the same.

[0079] (16) In the image stabilization device described in (4) above, when there are multiple focus areas that are the focus adjustment targets of the imaging optical system, the CPU 21 sets the positions of the multiple focus areas as the determined positions, and the image stabilization unit 21b calculates the average value of multiple amounts of shake calculated based on the multiple determined positions. This makes it possible to appropriately suppress image shake so that the image shake at the positions of the multiple focus areas is the same.

[0080] (17) In the image stabilization device of (7) above, when there are multiple main subjects according to the subject recognition information, the CPU 21 determines the positions of the multiple main subjects as the determined positions, and the image stabilization unit 21b calculates the average value of multiple amounts of blur calculated based on the multiple determined positions. This makes it possible to appropriately suppress image blur so that the image blur at the positions of the multiple focus areas is the same.

[0081] (18) In the image stabilization device of (8) above, when multiple faces are detected based on the facial recognition information, the CPU 21 determines the positions of the multiple faces as the determined positions, and the image stabilization unit 21b calculates the average value of the multiple amounts of blur calculated based on the multiple determined positions. This allows image blur to be appropriately suppressed so that the image blur at multiple focus area positions is the same.

[0082] The following modifications are also within the scope of the invention, and one or more of the modifications may be combined with the above-described embodiment or the embodiment described below. (Variation 1) In the first embodiment, an example has been described in which camera 1 performs image blur correction by operating image blur correction drive mechanism 37 of interchangeable lens 3. Instead, in Modification 1 of the first embodiment, camera 1 performs image blur correction by operating image blur correction drive mechanism 26 of camera body 2. Image blur correction according to Modification 1 of the first embodiment can be performed in the same way as in the first embodiment, and provides the same effects as in the first embodiment.

[0083] (Variation 2) In the case of calculating the image blur at the position of a face (subject 80) that is captured in the third method (3) described above in the first embodiment, for example, if the face is captured large on the screen, the CPU 21 may select the fifth method (5) above.

[0084] Fig. 7 is a diagram illustrating a second modification of the first embodiment. An example of determining one representative position from a plurality of candidates will be described with reference to Fig. 7. According to Fig. 7, a face (subject) is captured large on an image plane 70. The CPU 21 determines, for example, two points on the image plane 70, namely, the leftmost position Pa and the rightmost position Pb of the detected face, as candidate positions.

[0085] The CPU 21 determines the two candidate positions as positions for calculating image blur on the image plane 70. The angular blur calculation unit 201 calculates image blur at each of the positions Pa and Pb on the image plane 70. The angular blur calculation unit 201 further calculates the average of the calculated image blurs and performs image blur correction based on the average image blur value. The average value of the image blur is calculated by, for example, a simple average, but may also be calculated by a weighted average.

[0086] According to the second modification of the first embodiment described above, when a face is captured in a large image, image blur correction can be performed so that the image blur at both ends of the face is approximately the same. This reduces the sense of incongruity felt by the user compared to when the magnitude of image blur differs between the left and right sides of the face.

[0087] (Second embodiment) In the second embodiment, image blurring in a direction intersecting (different from) the direction of the detected angular velocity will be described. The camera 1 may be a single-lens reflex type as shown in FIG. 1, or a mirrorless type that does not include a mirror 24. Furthermore, the camera 1 may be configured as an integrated lens type in which the interchangeable lens 3 and the camera body 2 are integrated into one body. Furthermore, the imaging device is not limited to the camera 1, but may be a lens barrel equipped with an imaging sensor, a smartphone equipped with an imaging function, or the like.

[0088] FIG. 8 is a schematic diagram illustrating the direction in which angular velocity is detected by the angular velocity sensor 39a and image blur on the image plane 70 (the imaging plane of the image sensor 22). In FIG. 8, the origin of the coordinate system is the point where the image plane 70 intersects with the optical axis L1 of the interchangeable lens 3, the optical axis L1 of the interchangeable lens 3 is the Z axis, and the image plane 70 is represented as an XY plane. According to FIG. 8, the optical axis L1 intersects with the center of the imaging plane. The interchangeable lens 3 and subject 80 are located in the positive direction of the Z axis relative to the image plane 70. The angular velocity sensor 39a detects, for example, a rotation angle θ (pitch direction) around an axis (small-x axis) parallel to the X axis. When the subject 80 is located far away, the symbol f in FIGS. 3 and 4 represents the focal length.

[0089] When camera 1 shakes, the image of subject 80, which was located at coordinates (xp, yp) on image plane 70 before the shake, moves in the negative Y-axis direction and the positive X-axis direction after the shake. Therefore, the coordinates of the image of subject 80 become (xp + Δx2, yp - Δy2).

[0090] The mathematical expression representing the image blur Δy2 in the Y-axis direction is the above formula (1), as in the case described in the first embodiment. On the other hand, the image blur Δx2 in the X-axis direction can be expressed by the following equation (3). Δx2=f×xp / [(f 2 +yp 2 ) 1 / 2 ×cos(θ+tan -1 (yp / f))]-xp …(3) Here, the rotation angle in the pitch direction (representing the camera shake angle, generally about 0.5 degrees) is θ. When the subject 80 is far away, the symbol f in Figures 3 and 4 represents the focal length of the interchangeable lens 3.

[0091] According to the above equations (1) and (3), when the focal length f is sufficiently large compared to yp, the rotation angle θ (camera shake angle) is generally about 0.5 degrees, so Δx2 ≈ 0 can be considered. That is, whether the position of the image of the subject 80 on the image plane 70 is at the center of the image plane 70 (the origin in this example) or at a position away from the center, in other words, even if the distance from the optical axis L1 is different, when the rotation angle θ is detected in the pitch direction, only the Y-axis direction needs to be considered for image blur, and the X-axis direction can be ignored. Therefore, for example, if image blur correction is performed in the Y-axis direction based on image blur calculated at the center of the image plane 70, image blur can be suppressed for both the image of the subject 80 located at the center of the image plane 70 and the image of the subject 80 located away from the center of the image plane 70.

[0092] However, when the focal length f is not sufficiently larger than yp, such as when the interchangeable lens 3 is a wide-angle lens, Δx2≠0 according to the above formula (3). Therefore, when the pitch-direction rotation angle θ is detected, it is necessary to calculate not only the image blur in the Y-axis direction according to the above formula (1), but also the image blur in the X-axis direction according to the above formula (3). Otherwise, the image blur in the X-axis direction corresponding to the image blur Δx2 according to the above formula (3) will remain unsuppressed. The image blur Δx2 increases as the position where the image blur is calculated moves closer to the periphery of the image plane 70, that is, as the image height increases.

[0093] The CPU 21 determines the position on the image plane 70 where image blur is calculated, in the same way as in the first embodiment. That is, the CPU 21 selects one of the above methods (1) to (4) and determines the position on the image plane 70 where image blur is calculated. Then, the angular blur calculation unit 201 calculates image blur at the position determined by the CPU 21. The shake correction optical system target position calculation unit 203 calculates the amount of image blur based on the image blur calculated by the angular blur calculation unit 201 and the image blur calculated by the translational blur calculation unit 202.

[0094] Note that the image blur correction in the second embodiment includes correction in the Y-axis direction when the camera 1 rotates in the Pitch direction, and correction in the X-axis direction when the camera 1 rotates in the Yaw direction. The above description of the second embodiment has been made with respect to the point that when performing correction in the Y-axis direction when camera 1 is rotated in the pitch direction, if the focal length f is not sufficiently larger than yp, correction is also performed in the X-axis direction. When the camera 1 is rotated in the Yaw direction, the same correction as the above-described correction is required in the Y-axis direction. That is, although explanation with reference to the drawings is omitted, when performing correction in the X-axis direction when the camera 1 is rotated in the Yaw direction, if the focal length f cannot be said to be sufficiently larger than xp, correction is also required in the Y-axis direction. Furthermore, when the camera 1 rotates in both the pitch and yaw directions, image blur occurs simultaneously in both the X and Y axes due to both rotational movements, so the image blur caused by both rotational movements is added together with a positive or negative sign assigned to the direction of each of the X and Y axes, and then corrected in both the X and Y axes based on the image blur after addition.

[0095] Also, in the second embodiment, as in the first embodiment, the image blur calculated by the translational blur calculation unit 202 is treated as being approximately constant even if the position on the image plane 70 (the imaging plane of the image sensor 22) changes. The outline of the second embodiment is as follows. The angular blur calculation unit 201 calculates the image blur by determining the position for calculating the image blur as any position on the image plane 70. At this time, when the rotation angle θ in the pitch direction, for example, is detected, not only is the image blur in the Y-axis direction calculated using the above formula (1), but also the image blur in the X-axis direction is calculated using the above formula (3). The translational blur calculation unit 202 calculates the image blur by determining the position for calculating the image blur at, for example, the center of the image plane 70. The image blur correction optical system target position calculation unit 203 performs an addition calculation on the image blur calculated by the angular blur calculation unit 201 and the image blur calculated by the translational blur calculation unit 202, assigning a positive or negative sign depending on the direction of each of the X and Y axes, and then calculates the amount of image blur at the position of the image plane 70 based on the image blur in the X and Y axes after addition.

[0096] According to the second embodiment described above, the following advantageous effects can be obtained. (1) The image stabilization device of camera 1 includes a shake sensor 39 that detects shake in the Y-axis direction of the device, and a shake stabilization unit 21a that calculates the amount of shake of an image of subject 80 formed on image plane 70 by the imaging optical system based on the output of shake sensor 39. Shake stabilization unit 21a calculates image shake in the X-axis direction that intersects with the Y-axis direction. This makes it possible to suppress image shake in the X-axis direction that intersects with the Y-axis along which shake has been detected.

[0097] (2) In the image stabilization device described in (1) above, the image stabilization unit 21a calculates image shake in the Y-axis direction, so that image shake in the Y-axis direction where shake is detected can be suppressed.

[0098] (3) The image stabilization device of (1) or (2) above further includes a CPU 21 that determines a position on the image plane 70. The image stabilization unit 21a calculates the amount of image blur in the X-axis direction and the Y-axis direction based on the position determined by the CPU 21 and the rotation angle in the Y-axis direction detected by the shake sensor 39. This makes it possible to appropriately suppress image blur even when the position of the image plane 70 determined by the CPU 21 is not at the center of the image plane 70. This is particularly suitable when the focal length f of the interchangeable lens 3 is short (or when the angle of view is wide due to the relationship between the size of the image sensor 22 and the focal length f).

[0099] The following modifications are also within the scope of the invention, and one or more of the modifications may be combined with the above-described embodiment or the embodiment described below. (Variation 3) In the image stabilization described in the second embodiment, the CPU 21 performs correction taking into account the optical distortion caused by the interchangeable lens 3. FIG. 9 is a diagram illustrating an example in which distortion (e.g., barrel distortion) is caused by the interchangeable lens 3. The many solid-line circles represent an image of the subject 80 that would appear if it were assumed that the interchangeable lens 3 had no distortion. In contrast, the many hatched circles represent an image of the subject 80 that is distorted due to the influence of barrel distortion caused by the optical characteristics of the interchangeable lens 3.

[0100] Generally, the distortion of an interchangeable lens 3 is large in wide-angle lenses with short focal lengths, although this varies depending on the design. For this reason, as illustrated in FIG. 9 , the amount of distortion increases with increasing distance from the optical axis L1 of the imaging optical system (when the center O of the image plane 70 is aligned with the optical axis L1, the amount of distortion increases with increasing distance from the center O of the image plane 70). The amount of distortion appears as a positional deviation between the solid circle and the hatched circle shown in FIG. 9. In the example of FIG. 9 , the positional deviation between the solid circle and the hatched circle is greatest at a position far from the center O of the image plane 70 (in other words, where the image height is high); for example, the positional deviation at the lower right position is Δx in the X-axis direction and Δy in the Y-axis direction.

[0101] The schematic diagram shown in Fig. 8 is depicted as if there is no distortion caused by the imaging optical system, as shown by the solid-line circle in Fig. 9. Therefore, for example, if the position on image plane 70 for calculating image blur is set to a position away from the center O of image plane 70, and the image blur correction described in the second embodiment is performed as is, if distortion is present, image blur that cannot be corrected will occur.

[0102] Therefore, in Modification 3 of the second embodiment, when image stabilization described in the second embodiment is performed with an interchangeable lens 3 with large distortion attached to the camera body 2, image stabilization is performed assuming that there is distortion due to the imaging optical system, such as the hatched circle in FIG. 9.

[0103] 9, distortion information indicating the magnitude of distortion at which position on image plane 70, in which direction, is known as design information for interchangeable lens 3. For this reason, distortion information for the interchangeable lens 3 attached to camera body 2 is recorded in advance in memory 28. When CPU 21 detects that an interchangeable lens 3 with large distortion has been attached, it reads the corresponding distortion information from memory 28 and uses it in the calculation to calculate the image blur described above.

[0104] The shake correction optical system target position calculation unit 203 of the shake correction unit 21a performs a summation operation for each of the X and Y axes, assigning positive or negative signs to the image blur calculated by the angular shake calculation unit 201, the image blur calculated by the translational shake calculation unit 202, and the distortion aberration information read out from the memory 28, depending on the direction of the image blur. Then, based on the image blur in the X and Y axes after the summation, it calculates the amount of image blur at the position of the image plane 70.

[0105] In the above description, an example in which barrel distortion occurs has been described, but the same applies to the case in which pincushion distortion occurs.

[0106] According to the third modification of the second embodiment described above, image blur can be appropriately corrected even if distortion occurs. Furthermore, even if the optical distortion caused by the interchangeable lens 3 is large, image blur can be appropriately suppressed at positions other than the center of the image plane 70.

[0107] (Third embodiment) In the third embodiment, an interchangeable lens 3A is attached to a camera body 2A. The interchangeable lens 3A differs from the interchangeable lens 3 in that a shake correction unit 40 is added to the interchangeable lens 3A. A detection signal from a shake sensor 39 is sent to the shake correction unit 40. Camera body 2A differs from camera body 2 in that it additionally includes a shake sensor (motion detection unit, shake detection unit) 31. A detection signal from shake sensor 31 is sent to CPU 21 (shake correction unit 21a). Shake sensor 31 has the same function as shake sensor 39.

[0108] In the third embodiment, when an interchangeable lens 3A equipped with a shake correction drive mechanism 37 is attached to a camera body 2A, image blur correction performed by operating the shake correction drive mechanism 37 of the interchangeable lens 3A and image blur correction performed by operating the shake correction drive mechanism 26 of the camera body 2A are used in combination. On the other hand, when an interchangeable lens 3A that does not have a shake correction drive mechanism 37 is attached to the camera body 2A, image shake correction similar to that in variant 1 of the first embodiment is performed by operating the shake correction drive mechanism 26 of the camera body 2A.

[0109] 10 is a diagram showing the main configuration of a camera 1A according to the third embodiment. The camera 1A is composed of a camera body 2A and an interchangeable lens 3A. The interchangeable lens 3A is attached to the camera body 2A via a mount (not shown). When the interchangeable lens 3A is attached to the camera body 2A, the camera body 2A and the interchangeable lens 3A are electrically connected, enabling communication between the camera body 2A and the interchangeable lens 3A. Communication between the camera body 2A and the interchangeable lens 3A may also be performed via wireless communication. 10, the same components as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and the description thereof will be omitted.

[0110] 11 is a diagram illustrating the shake correction section 40 of the interchangeable lens 3 A. The shake correction section 40 has an angular shake calculation section 401, a translational shake calculation section 402, and a shake correction optical system target position calculation section 403. The angular shake calculation unit 401 calculates image blur in the Y-axis direction due to rotational movement, and, if necessary, image blur in the X-axis direction, using a detection signal from the angular velocity sensor 39a about an axis parallel to the X-axis (pitch direction).Furthermore, the angular shake calculation unit 201 calculates image blur in the X-axis direction due to rotational movement, and, if necessary, image blur in the Y-axis direction, using a detection signal from the angular velocity sensor 39a about an axis parallel to the Y-axis (yaw direction).

[0111] The translational shake calculation unit 402 calculates the image blur in the X-axis direction caused by translational motion using the detection signal in the X-axis direction by the acceleration sensor 39b. Also, the translational shake calculation unit 402 calculates the image blur in the Y-axis direction caused by translational motion using the detection signal in the Y-axis direction by the acceleration sensor 39b.

[0112] The image blur correction optical system target position calculation unit 403 calculates the image blur in the X-axis direction and the Y-axis direction by adding the image blur in the X-axis direction and the Y-axis direction calculated by the angular blur calculation unit 401 and the image blur in the X-axis direction and the Y-axis direction calculated by the translational blur calculation unit 402.

[0113] Furthermore, the image blur correction optical system target position calculation unit 403 calculates the amount of image blur on the image plane 70 at a position to be described later, based on the image blur in the X-axis direction and the Y-axis direction after the summation, the shooting magnification (calculated based on the position of the zoom optical system 31), and the distance from the camera 1A to the subject 80 (calculated based on the position of the focus optical system 32).

[0114] The image blur correction optical system target position calculation unit 403 calculates the target position of the image blur correction optical system 33 based on the calculated amount of image blur to operate the image blur correction drive mechanism 37 of the interchangeable lens 3A. The image blur correction optical system target position calculation unit 403 then sends a signal indicating the target position to the image blur correction drive mechanism 37 of the interchangeable lens 3A.

[0115] The camera 1A may be either a single-lens reflex type as shown in FIG. 10, or a mirrorless type that does not include the mirror 24. Furthermore, if the camera is equipped with a shake correction drive mechanism 26 that moves the image sensor 22 back and forth and a shake correction drive mechanism 37 that moves the shake correction optical system 33 back and forth, the camera may be configured as a lens-integrated camera in which the interchangeable lens 3A and the camera body 2A are integrated.

[0116] <Image stabilization used in combination> The following describes image blur correction that combines image blur correction by the interchangeable lens 3A and image blur correction by the camera body 2A. The calculation of image blur by the angular blur calculation unit 201 and the calculation of image blur by the translational blur calculation unit 202 are the same as those in the first and second embodiments. However, it differs from the first and second embodiments in the following respects: One difference is that in image blur correction using interchangeable lens 3A, the center of image plane 70 is selected as the position for calculating image blur, while in image blur correction using camera body 2A, any position on image plane 70 is selected as the position for calculating image blur. Another difference is that image blur correction by the interchangeable lens 3A and image blur correction by the camera body 2A are performed based on the sharing ratio determined by the CPU 21 of the camera body 2A. The sharing ratio will be explained later.

[0117] <Position for calculating image blur> CPU 21 determines the position at which image blur correction section 40 of interchangeable lens 3A calculates image blur to be, for example, the center of image plane 70, and determines the position at which image blur correction section 21a of camera body 2A calculates image blur to be any position on image plane 70. As a result, angular shake calculation section 401 of interchangeable lens 3A calculates the amount of shake correction (L) based on the image blur at the center position of image plane 70 and the sharing ratio of interchangeable lens 3A determined by CPU 21. Angular shake calculation section 201 of camera body 2A calculates the amount of shake correction (B) based on the image blur at a position different from the center of image plane 70 determined by CPU 21 and the sharing ratio of camera body 2A determined by CPU 21. When the CPU 21 determines the position for calculating image blur at a position different from the center of the image plane 70, the CPU 21 determines the position by one of the methods (1) to (4) in the first embodiment.

[0118] When the position for calculating the image blur is the center of the image plane 70, the mathematical expression for the image blur Δy1 in the Y-axis direction is the above formula (2), as explained in the first embodiment. Furthermore, when the position for calculating the image blur is a position different from the center of the image plane 70, the equation expressing the image blur Δy2 in the Y-axis direction is the above equation (1), as explained in the first embodiment.

[0119] <Sharing ratio> The CPU 21 determines the ratio between image blur correction by the interchangeable lens 3A and image blur correction by the camera body 2A. In this example, the CPU 21 determines the ratio as 50:50, for example. This ratio may also be 70:30 or 40:60.

[0120] When the sharing ratio determined by the CPU 21 is 50:50, the angular blur calculation unit 401 of the interchangeable lens 3A calculates the image blur V(L) to be shared by the interchangeable lens 3A as shown in the following equation (4). The reason for multiplying by 2 on the right side is because the sharing ratio is set to 50%: V(L)=Δy1 / 2=f×tanθ / 2 (4) where Δy1 is the image blur in the Y-axis direction at the center of the image plane 70. Also, the rotation angle in the pitch direction (representing the camera shake angle, generally about 0.5 degrees) is θ. When the subject 80 is far away, the symbol f represents the focal length of the interchangeable lens 3A.

[0121] On the other hand, when the sharing ratio determined by the CPU 21 is 50:50, the angular shake calculation section 201 of the camera body 2A calculates the image shake V(B) to be shared by the camera body 2A as shown in the following equation (5). V(B)=Δy1 / 2+d =f×tanθ / 2+d …(5) Here, d=Δy2−Δy1, where Δy2 is the image blur in the Y-axis direction at a position different from the center of the image plane 70.

[0122] The image blur correction optical system target position calculation unit 403 of the interchangeable lens 3A calculates the target position of the image blur correction optical system 33 for image blur correction, which is performed by operating the image blur correction drive mechanism 37 of the interchangeable lens 3A, based on the image blur V(L) calculated by the angular blur calculation unit 401 and the image blur calculated by the translational blur calculation unit 402.

[0123] Furthermore, the blur correction optical system target position calculation unit 203 of the camera body 2A calculates the target position of the image sensor 22 for image blur correction, which is performed by operating the blur correction drive mechanism 26 of the camera body 2A, based on the image blur V(B) calculated by the angular blur calculation unit 201 and the image blur calculated by the translational blur calculation unit 202. Image correction optical system target position calculation unit 403 of interchangeable lens 3A further sends a signal indicating the target position to image correction drive mechanism 37 of interchangeable lens 3A. Also, image correction optical system target position calculation unit 203 of camera body 2A further sends a signal indicating the target position to image correction drive mechanism 26 of camera body 2A.

[0124] In the third embodiment, image blur correction by interchangeable lens 3A is performed based on image blur calculated by angular shake calculation unit 401 at the center position of image plane 70. Also, image blur correction by camera body 2A is performed based on image blur calculated by angular shake calculation unit 201 at a position other than the center of image plane 70.

[0125] Note that the image blur correction in the third embodiment includes correction in the Y-axis direction when camera 1A rotates in the Pitch direction, and correction in the X-axis direction when camera 1A rotates in the Yaw direction. The above-described third embodiment has been described as a representative example of correction in the Y-axis direction when camera 1A is rotated in the pitch direction. Therefore, when camera 1A is also rotated in the yaw direction, a correction similar to the correction described above is required for the X-axis direction. Correction in the Y-axis direction when camera 1A is rotated in the pitch direction and correction in the X-axis direction when camera 1A is rotated in the yaw direction are the same except for the direction, so a description of the X-axis direction will be omitted.

[0126] Furthermore, when camera 1A rotates in both the pitch and yaw directions, image blurring occurs simultaneously in both the X and Y axes due to both rotational movements, so the image blurring caused by both rotational movements is added together with a positive or negative sign assigned to the direction of each of the X and Y axes, and then corrected in both the X and Y axes based on the image blurring after addition.

[0127] In the third embodiment, as in the first and second embodiments, the image blur calculated by the translational blur calculation unit 202 and the translational blur calculation unit 402 is treated as being approximately constant even if the position on the image plane 70 changes. The third embodiment is outlined below. Angular shake calculation section 401 of shake correction section 40 of interchangeable lens 3A calculates image shake at the center position of image plane 70. Angular shake calculation section 201 of shake correction section 21a of camera body 2A calculates image shake at a position different from the center of image plane 70. The angular shake calculation unit 401 of the interchangeable lens 3A sets the image shake V(L) that is to be shared by the interchangeable lens 3A (for example, a sharing ratio of 50%) to 1 / 2 of the image shake Δy1 at the center of the image plane 70, and the angular shake calculation unit 201 of the camera body 2A sets the image shake V(B) that is to be shared by the camera body 2A to V(L)+d, where d is the difference between the image shake Δy2 at a position different from the center of the image plane 70 and the above-mentioned Δy1. The translational shake calculation unit 402 of the interchangeable lens 3A allocates the image blur to the interchangeable lens 3A (for example, a 50% allocation ratio) to, for example, half of the image blur at the center of the image plane 70. The translational shake calculation unit 202 of the camera body 2A allocates the image blur to the camera body 2A to, for example, half of the image blur at the center of the image plane 70. The image blur correction optical system target position calculation unit 403 of the interchangeable lens 3A performs an addition calculation on the image blur V(L) calculated by the angular blur calculation unit 401 and the image blur calculated by the translational blur calculation unit 402, assigning a positive or negative sign depending on the direction of the X-axis and Y-axis, respectively. Then, based on the image blur in the X-axis and Y-axis directions after addition, it calculates the amount of image blur at the center position of the image plane 70. The image blur correction optical system target position calculation unit 203 in the camera body 2A performs an addition calculation on the image blur V(B) calculated by the angular blur calculation unit 201 and the image blur calculated by the translational blur calculation unit 202, assigning a positive or negative sign depending on the direction of the X-axis and Y-axis, respectively. Then, based on the image blur in the X-axis and Y-axis directions after addition, it calculates the amount of image blur at a position different from the center of the image plane 70.

[0128] According to the third embodiment described above, the following advantageous effects can be obtained. (1) The image stabilization device of camera 1A is provided in interchangeable lens 3A with shake sensor 39 that detects shake of the device, shake correction unit 40 that calculates the amount of shake of the image of subject 80 formed on image plane 70 by the imaging optical system based on the output of shake sensor 39, and shake correction drive mechanism 37 that moves shake correction optical system 33 in a direction to reduce the amount of shake based on the output of shake correction unit 40. Also provided in camera body 2A are shake sensor 31 that detects shake of the device, shake correction unit 21b that calculates the amount of shake of the image of subject 80 formed on image plane 70 by the imaging optical system based on the output of shake sensor 31, shake correction drive mechanism 26 that moves image sensor 22 that captures the image of subject 80 on image plane 70 in a direction to reduce the amount of shake based on the output of shake correction unit 21a, and CPU 21 that determines the position on image plane 70.

[0129] The image blur correction unit 40 of the interchangeable lens 3A calculates an image blur Δy1 based on a first position (the center of the image plane 70) that is predetermined on the image plane 70 and the shake detected by the shake sensor 39. The image blur correction unit 40 sets the image blur V(L) that is to be shared by the interchangeable lens 3A (for example, a sharing ratio of 50%) to be 1 / 2 of the image blur Δy1. The shake correction unit 21b of the camera body 2A calculates an image blur Δy2 based on a second position (a position different from the center) determined by the CPU 21 and the shake detected by the shake sensor 31, and an image blur Δy1 based on a first position (the center of the image plane 70) predetermined on the image plane 70 and the shake detected by the shake sensor 31. The shake correction unit 21b further calculates the difference d between the image blur Δy2 and the image blur Δy1. The angular shake calculation unit 201 sets the image blur V(B) allocated to the camera body 2A to V(L)+d. This makes it possible to appropriately suppress image blur even when the position determined by the CPU 21 is not the center of the image plane 70. This is particularly suitable when the focal length f of the interchangeable lens 3A is short (or when the angle of view is wide due to the relationship between the size of the image sensor 22 and the focal length f).

[0130] (2) In the image stabilization device described in (1) above, image stabilization unit 40 of interchangeable lens 3A outputs 50% of image blur Δy1 to image stabilization drive mechanism 37, and image stabilization unit 21a of camera body 2A outputs the remaining 50% of image blur Δy1 and the difference d to image stabilization drive mechanism 26. Compared to when image stabilization drive mechanism 26 and image stabilization drive mechanism 37 are not used together, the travel distances of image stabilization drive mechanism 26 and image stabilization drive mechanism 37 can each be kept small.

[0131] The CPU 21 may determine the sharing ratio such that the image shake correction by the interchangeable lens 3A is 100% and the image shake correction by the camera body 2A is 0%. In this case, the angular shake calculation unit 401 of the interchangeable lens 3A sets the image shake V(L) shared by the interchangeable lens 3A to 100%, and the angular shake calculation unit 201 of the camera body 2A sets the image shake V(B) shared by the camera body 2A to d. d is the difference between the image shake Δy2 at a position different from the center of the image plane 70 and the image shake Δy1 at the center of the image plane 70.

[0132] The following modifications are also within the scope of the invention, and one or more of the modifications may be combined with the above-described embodiment or the embodiment described below. (Variation 4) In a fourth modification of the third embodiment, the CPU 21 determines, for example, two positions (referred to as a first position and a second position) on the image plane 70 as positions for calculating image blur. The angular blur calculation unit 401 of the interchangeable lens 3A calculates image blur for the first position determined by the CPU 21. The angular blur calculation unit 201 of the camera body 2A calculates image blur for the first position and the second position determined by the CPU 21. The CPU 21 determines the first position and the second position for calculating image blur by any of the methods (1) to (4) in the first embodiment.

[0133] Variation 4 of the third embodiment differs from the third embodiment in that it includes a case where both the first position and the second position are positions different from the center of the image plane 70. On the other hand, Variation 4 of the third embodiment is similar to the third embodiment in that the CPU 21 determines the ratio of image blur correction performed by the interchangeable lens 3A to image blur correction performed by the camera body 2A.

[0134] When the first position or the second position for calculating the image blur is the center of the image plane 70, the equation expressing the image blur Δy1 in the Y-axis direction is the above equation (2), as described in the first embodiment. Furthermore, when the first and second positions for calculating the image blur are positions different from the center of the image plane 70, the formula expressing the image blur Δy2 in the Y-axis direction is the above formula (1), as explained in the first embodiment.

[0135] When the sharing ratio determined by the CPU 21 is, for example, 50:50, the angular shake calculation unit 401 of the interchangeable lens 3A calculates the image blur V(L) to be shared by the interchangeable lens 3A, as shown in the following equation (6). The reason for multiplying by 2 on the right-hand side is that the sharing ratio is set to 50%. V(L)=Δy2a / 2 …(6) Here, Δy2a is the image blur in the Y-axis direction at a first position different from the center of the image plane 70.

[0136] Furthermore, when the sharing ratio determined by the CPU 21 is 50:50, the angular shake calculation section 201 of the camera body 2A calculates the image shake V(B) to be shared by the camera body 2A as shown in the following equation (7). V(B)=Δy2a / 2+d2 …(7) Here, d2=Δy2b−Δy2a, where Δy2b is the image blur in the Y-axis direction at a second position different from the center of the image plane 70.

[0137] The image blur correction optical system target position calculation unit 403 of the interchangeable lens 3A calculates the target position of the image blur correction optical system 33 for image blur correction, which is performed by operating the image blur correction drive mechanism 37 of the interchangeable lens 3A, based on the image blur V(L) calculated by the angular blur calculation unit 401 and the image blur calculated by the translational blur calculation unit 402.

[0138] Furthermore, the blur correction optical system target position calculation unit 203 of the camera body 2A calculates the target position of the image sensor 22 for image blur correction, which is performed by operating the blur correction drive mechanism 26 of the camera body 2A, based on the image blur V(B) calculated by the angular blur calculation unit 201 and the image blur calculated by the translational blur calculation unit 202. Image correction optical system target position calculation unit 403 of interchangeable lens 3A further sends a signal indicating the target position to image correction drive mechanism 37 of interchangeable lens 3A. Also, image correction optical system target position calculation unit 203 of camera body 2A further sends a signal indicating the target position to image correction drive mechanism 26 of camera body 2A.

[0139] In Modification 4 of the third embodiment, image blur correction by interchangeable lens 3A is performed based on image blur calculated by angular shake calculation unit 401 at a first position on image plane 70. Also, image blur correction by camera body 2A is performed based on image blur calculated by angular shake calculation unit 201 at a second position on image plane 70.

[0140] Note that the image blur correction in the fourth modification of the third embodiment includes correction in the Y-axis direction when the camera 1A is rotated in the Pitch direction, and correction in the X-axis direction when the camera 1A is rotated in the Yaw direction. The above-described explanation of the fourth modification of the third embodiment has been given mainly on the correction in the Y-axis direction when the camera 1A is rotated in the pitch direction. Therefore, when the camera 1A is also rotated in the yaw direction, the same correction as that described above is required for the X-axis direction. Correction in the Y-axis direction when camera 1A is rotated in the Pitch direction and correction in the X-axis direction when camera 1A is rotated in the Yaw direction are the same except for the direction, so explanation of the X-axis direction will be omitted.

[0141] Furthermore, when camera 1A rotates in both the pitch and yaw directions, image blurring occurs simultaneously in both the X and Y axes due to both rotational movements, so the image blurring caused by both rotational movements is added together with a positive or negative sign assigned to the direction of each of the X and Y axes, and then corrected in both the X and Y axes based on the image blurring after addition.

[0142] Furthermore, in the fourth modification of the third embodiment, as in the first to third embodiments, the image blur calculated by the translational shake calculation unit 202 and the translational shake calculation unit 402 is treated as being substantially constant even if the position on the image plane 70 (the imaging plane of the image sensor 22) changes. The outline of the fourth modification of the third embodiment is as follows. Angular shake calculation section 401 of shake correction section 40 of interchangeable lens 3A calculates image shake at a first position on image plane 70. Angular shake calculation section 201 of shake correction section 21a of camera body 2A calculates image shake at a second position on image plane 70. The angular shake calculation unit 401 of the interchangeable lens 3A sets the image shake V(L) to be shared by the interchangeable lens 3A (for example, a sharing ratio of 50%) to 1 / 2 of the image shake Δy2a at the first position on the image plane 70, and the angular shake calculation unit 201 of the camera body 2A sets the image shake V(B) to be shared by the camera body 2A to V(L)+d2, where d2 is the difference between the image shake Δy2b at the second position on the image plane 70 and the above-mentioned Δy2a. The translational shake calculation unit 402 of the interchangeable lens 3A allocates the image blur to the interchangeable lens 3A (for example, a 50% allocation ratio) to, for example, half of the image blur at the center of the image plane 70. The translational shake calculation unit 202 of the camera body 2A allocates the image blur to the camera body 2A to, for example, half of the image blur at the center of the image plane 70. The image blur correction optical system target position calculation unit 403 of the interchangeable lens 3A performs an addition calculation on the image blur V(L) calculated by the angular blur calculation unit 401 and the image blur calculated by the translational blur calculation unit 402, assigning a positive or negative sign depending on the direction of each of the X and Y axes, and then calculates the amount of image blur at a first position on the image plane 70 based on the image blur in the X and Y axes after the addition. The image blur correction optical system target position calculation unit 203 in the camera body 2A performs an addition calculation on the image blur V(B) calculated by the angular blur calculation unit 201 and the image blur calculated by the translational blur calculation unit 202, assigning a positive or negative sign depending on the direction of each of the X and Y axes, and then calculates the amount of image blur at a second position on the image plane 70 based on the image blur in the X and Y axes after the addition.

[0143] According to the fourth modification of the third embodiment described above, the following advantageous effects can be obtained. (1) The image stabilization device of camera 1A is provided in interchangeable lens 3A with shake sensor 39 that detects shake of the device, shake correction unit 40 that calculates the amount of shake of the image of subject 80 formed on image plane 70 by the imaging optical system based on the output of shake sensor 39, and shake correction drive mechanism 37 that moves image stabilization optical system 33 in a direction to reduce the amount of shake based on the output of shake correction unit 40. Also provided in camera body 2A are shake sensor 31 that detects shake of the device, shake correction unit 21a that calculates the amount of shake of the image of subject 80 formed on image plane 70 by the imaging optical system based on the output of shake sensor 31, shake correction drive mechanism 26 that moves image sensor 22 that captures the image of subject 80 on image plane 70 in a direction to reduce the amount of shake based on the output of shake correction unit 21a, and CPU 21 that determines a first position and a second position on image plane 70.

[0144] The image blur correction unit 40 of the interchangeable lens 3A calculates the image blur Δy2a based on the first position and the shake detected by the shake sensor 39. The image blur correction unit 40 sets the image blur V(L) that is to be shared by the interchangeable lens 3A (for example, a sharing ratio of 50%) to 1 / 2 of the image blur Δy2a. The shake correction unit 21a of the camera body 2A calculates an image blur Δy2a based on the first position and the shake detected by the shake sensor 31, and an image blur Δy2b based on the second position and the shake detected by the shake sensor 31. The shake correction unit 21b further calculates the difference d2 between the image blur Δy2a and the image blur Δy2b. The angular shake calculation unit 201 sets the image blur V(B) allocated to the camera body 2A to V(L)+d2. This makes it possible to appropriately suppress image blur at the second position determined by the CPU 21 other than the center of the image plane 70. This is particularly suitable when the focal length f of the interchangeable lens 3A is short (or when the angle of view is wide due to the relationship between the size of the image sensor 22 and the focal length f).

[0145] (2) In the image stabilization device described in (1) above, image stabilization section 40 of interchangeable lens 3A outputs 50% of image shake Δy2a to image stabilization drive mechanism 37, and image stabilization section 21b of camera body 2A outputs the remaining 50% of Δy2a and the difference d2 to image stabilization drive mechanism 26. Compared to when image stabilization drive mechanism 26 and image stabilization drive mechanism 37 are not used together, the travel distances of image stabilization drive mechanism 26 and image stabilization drive mechanism 37 can each be kept small.

[0146] The CPU 21 may determine the sharing ratio such that the image shake correction by the interchangeable lens 3A is 100% and the image shake correction by the camera body 2A is 0%. In this case, the angular shake calculation unit 401 of the interchangeable lens 3A sets the image shake V(L) shared by the interchangeable lens 3A to 100%, and the angular shake calculation unit 201 of the camera body 2A sets the image shake V(B) shared by the camera body 2A to d2. d2 is the difference between the image shake Δy2a at a first position different from the center of the image plane 70 and the image shake Δy2b at a second position different from the center of the image plane 70.

[0147] (Variation 5) The image blur correction calculation based on the image blur V(B) of the above formulas (5) and (7) may be performed by the image blur correction unit 40 of the interchangeable lens 3A, and the image blur correction calculation based on the image blur V(L) of the above formulas (4) and (6) may be performed by the image blur correction unit 21a of the camera body 2A. According to the fifth modification of the third embodiment, the position of the image plane 70 where the image blur is calculated for the image blur correction by the interchangeable lens 3A and the position of the image plane 70 where the image blur is calculated for the image blur correction by the camera body 2A can be interchanged with the third embodiment and the fourth modification of the third embodiment.

[0148] (Variation 6) Although the description of the second embodiment was omitted in the above explanations of the third embodiment and variant 4 of the third embodiment, if focal length f is not sufficiently larger than yp when making correction in the Y axis direction when camera 1A is rotated in the pitch direction, correction similar to that in the second embodiment is also made in the X axis direction. Angular shake calculation unit 201 and angular shake calculation unit 401 perform addition calculations for the X and Y axes, assigning a positive or negative sign depending on the direction of shake.

[0149] The same applies to correction in the X-axis direction when camera 1A is rotated in the Yaw direction. That is, when correcting the X-axis direction when camera 1A is rotated in the Yaw direction, if focal length f is not sufficiently larger than xp, a similar correction is made in the Y-axis direction. Angular shake calculation unit 201 and angular shake calculation unit 401 perform addition calculations for each of the X and Y axes, assigning a positive or negative sign depending on the direction of shake.

[0150] (Fourth embodiment) In the fourth embodiment, image stabilization is performed solely by an interchangeable lens 3A using a camera 1A shown in Fig. 10. The camera 1A may be a single-lens reflex type as shown in Fig. 10, or a mirrorless type that does not include a mirror 24. Furthermore, the interchangeable lens 3A and the camera body 2A may be integrated into one body to form an integrated lens camera.

[0151] <Position for calculating image blur> The CPU 21 of the camera body 2A in the fourth embodiment determines a position on the image plane 70 where the image of the main subject is likely to exist, for example, by any of the methods (1) to (4) in the first embodiment. Then, the CPU 21 transmits information indicating the position determined on the image plane 70 to the image blur correction unit 40 of the interchangeable lens 3A.

[0152] The timing at which the CPU 21 of the camera body 2A transmits information about the position on the image plane 70 at which image blur is calculated to the blur correction unit 40 is, for example, when the CPU 21 determines the position on the image plane 70 at which image blur is calculated (including when the position is newly determined or updated). The CPU 21 promptly notifies the image blur correction unit 40 of the position information by, for example, including the above-mentioned position information in regular communication between the camera body 2A and the interchangeable lens 3A, or by including the above-mentioned position information in communication from the camera body 2A to the interchangeable lens 3A instructing the interchangeable lens 3A to start image blur correction.

[0153] The angular shake calculation unit 401 of the shake correction unit 40 calculates the image shake at the position indicated by the information received from the CPU 21, and performs image shake correction based on this image shake.

[0154] When the position for calculating the image blur is the center of the image plane 70, the mathematical expression for the image blur Δy1 in the Y-axis direction is the above formula (2), as explained in the first embodiment. Furthermore, when the position for calculating the image blur is a position different from the center of the image plane 70, the equation expressing the image blur Δy2 in the Y-axis direction is the above equation (1), as explained in the first embodiment.

[0155] The image blur correction in the fourth embodiment includes correction in the Y-axis direction when the camera 1A rotates in the Pitch direction, and correction in the X-axis direction when the camera 1A rotates in the Yaw direction. The above formulas (1) and (2) represent the correction in the Y-axis direction when camera 1A is rotated in the Pitch direction. When camera 1A is rotated in the Yaw direction, the same correction as the above-mentioned correction is required in the X-axis direction. The correction in the Y-axis direction when camera 1A is rotated in the Pitch direction and the correction in the X-axis direction when camera 1A is rotated in the Yaw direction are the same except for the direction, so the explanation of the correction in the X-axis direction will be omitted.

[0156] Furthermore, when camera 1A rotates in both the pitch and yaw directions, image blurring occurs simultaneously in both the X and Y axes due to both rotational movements, so the image blurring caused by both rotational movements is added together with a positive or negative sign assigned to the direction of each of the X and Y axes, and then corrected in both the X and Y axes based on the image blurring after addition.

[0157] In the fourth embodiment, as in the third embodiment, the image blur calculated by the translational blur calculation unit 402 is treated as being approximately constant even if the position on the image plane 70 (the imaging plane of the imaging element 22) varies. The outline of the fourth embodiment is as follows. The angular shake calculation section 401 of the shake correction section 40 of the interchangeable lens 3A determines the position on the image plane 70 for calculating image shake to be the position notified by the CPU 21 of the camera body 2A, and calculates the image shake. The translational blur calculation unit 402 calculates the image blur at the center of the image plane 70, for example. The image blur correction optical system target position calculation unit 403 performs an addition calculation on the image blur calculated by the angular blur calculation unit 401 and the image blur calculated by the translational blur calculation unit 402, assigning a positive or negative sign depending on the direction of each of the X and Y axes. Then, based on the image blur in the X and Y axes after addition, it calculates the amount of image blur at the position of the image plane 70 notified by the CPU 21 of the camera body 2A.

[0158] According to the fourth embodiment described above, the following advantageous effects can be obtained. (1) The image stabilization device includes an interchangeable lens 3A having an image sensor 22 that captures a subject image formed on an image plane 70 by an interchangeable lens 3A, a CPU 21 that determines a position on the image plane 70, and a camera body 2A that has the CPU 21 that transmits information about the position determined by the CPU 21 to the interchangeable lens 3A, an image stabilization optical system 33 that performs image stabilization, a image stabilization unit 40 that receives position information from the camera body 2A, an image stabilization unit 40 that calculates image blur Δy2 based on the position received from the camera body 2A and shake detected by a shake sensor 39, and a image stabilization drive mechanism 37 that moves the image stabilization optical system 33 in a direction that suppresses image blur Δy2. This allows image blur to be appropriately suppressed, for example, at positions other than the center of the image plane 70 determined by the CPU 21 of the camera body 2A. This is particularly suitable when the focal length f of the interchangeable lens 3A is short (or when the angle of view is wide due to the relationship between the size of the image sensor 22 and the focal length f).

[0159] (2) The image blur correction unit 40 of the interchangeable lens 3A calculates the image blur Δy2 based on the output of the vibration sensor 39 and the focal length f of the interchangeable lens 3A. This makes it possible to properly calculate the image blur Δy2 at positions other than the center of the image plane 70, and to properly suppress the image blur based on this image blur Δy2.

[0160] (Fifth embodiment) The fifth embodiment uses the camera 1A of FIG. 10, similarly to the fourth embodiment. Image blur correction in the fifth embodiment is performed solely by operating the blur correction drive mechanism 37 of the interchangeable lens 3A, but differs from the fourth embodiment in that calculations are performed by both the blur correction unit 21a of the CPU 21 of the camera body 2A and the blur correction unit 40 of the interchangeable lens 3A. The camera 1A may be a single-lens reflex type as shown in FIG. 10, or a mirrorless type that does not include the mirror 24. Furthermore, the interchangeable lens 3A and the camera body 2A may be integrated into one body to form an integrated lens camera.

[0161] <Position for calculating image blur> CPU 21 of camera body 2A determines a position on image plane 70 where the image of the main subject is likely to exist, for example, by any of methods (1) to (4) in the first embodiment. CPU 21 then determines the center of image plane 70 as a first position, and the position determined as described above as a second position.

[0162] <Camera body calculation> The image blur correction unit 21a of the CPU 21 calculates the image blur at the first position and the second position on the image plane 70. Specifically, angular shake calculation unit 201 calculates image blur in the Y-axis direction due to rotational movement, and, if necessary, image blur in the X-axis direction, using a detection signal about an axis parallel to the X-axis (pitch direction) from the angular velocity sensor of shake sensor 31. Also, angular shake calculation unit 201 calculates image blur in the X-axis direction due to rotational movement, and, if necessary, image blur in the Y-axis direction, using a detection signal about an axis parallel to the Y-axis (yaw direction) from the angular velocity sensor of shake sensor 31.

[0163] When the position for calculating the image blur is the first position, the mathematical expression representing the image blur Δy1 in the Y-axis direction is the above formula (2), as explained in the first embodiment. Furthermore, when the position for calculating the image blur is the second position, which is a position different from the center of the image plane 70, the formula expressing the image blur Δy2 in the Y-axis direction is the above formula (1), as explained in the first embodiment.

[0164] In the fifth embodiment, the image blur correction unit 21a of the CPU 21 further calculates the ratio g of the image blur Δy1 at the first position to the image blur Δy2 at the second position using the following equation (8). g=Δy2 / Δy1 ……(8) The above g is referred to as the correction coefficient g. The CPU 21 transmits information indicating the correction coefficient g to the image stabilization unit 40 of the interchangeable lens 3A. Instead of the information indicating the ratio between Δy2 and Δy1, the CPU 21 may transmit information indicating the difference between Δy2 and Δy1 to the image stabilization unit 40 of the interchangeable lens 3A.

[0165] The timing at which the CPU 21 of the camera body 2A transmits information indicating the correction coefficient g to the blur correction unit 40 is, for example, when the CPU 21 calculates the correction coefficient g after determining (including when the CPU 21 determines a new position and a second position on the image plane 70 for calculating image blur and when the CPU 21 updates the positions). The CPU 21 promptly notifies the image blur correction unit 40 of the information on the correction coefficient g by, for example, including the information on the correction coefficient g in regular communication between the camera body 2A and the interchangeable lens 3A, or by including the information on the correction coefficient g in communication from the camera body 2A to the interchangeable lens 3A instructing the interchangeable lens 3A to start image blur correction.

[0166] <Calculations on the interchangeable lens side> Like angular shake calculation section 201 of shake correction section 21a of camera body 2A, angular shake calculation section 401 of shake correction section 40 uses a detection signal from angular velocity sensor 39a about an axis parallel to the X axis (pitch direction) to calculate image shake in the Y axis direction due to rotational movement, and, if necessary, image shake in the X axis direction. Also, angular shake calculation section 401 uses a detection signal from angular velocity sensor 39a about an axis parallel to the Y axis (yaw direction) to calculate image shake in the X axis direction due to rotational movement, and, if necessary, image shake in the Y axis direction.

[0167] <Position for calculating image blur> The image blur correction unit 40 in the fifth embodiment calculates image blur at the same position as the first position determined by the CPU 21 of the camera body 2A, which in this example is the center of the image plane 70. Because the position for calculating image blur is the center of the image plane 70, the mathematical expression expressing the image blur Δy1 in the Y-axis direction is the above formula (2), as explained in the first embodiment. The angular shake calculation unit 401 calculates the image shake Δy2 in the Y-axis direction at the second position of the image plane 70 by multiplying the image shake Δy1 in the Y-axis direction by a correction coefficient g based on information received from the camera body 2A by the receiving unit. If the information received from the camera body 2A indicates the difference between Δy2 and Δy1, the angular shake calculation unit 401 calculates the image shake Δy2 by adding the received information to the image shake Δy1.

[0168] The translational shake calculation unit 402 calculates the image blur in the X-axis direction caused by translational motion using the detection signal in the X-axis direction by the acceleration sensor 39b. Also, the translational shake calculation unit 402 calculates the image blur in the Y-axis direction caused by translational motion using the detection signal in the Y-axis direction by the acceleration sensor 39b.

[0169] The image blur correction optical system target position calculation unit 403 calculates the image blur in the X-axis direction and the Y-axis direction by adding the image blur in the X-axis direction and the Y-axis direction calculated by the angular blur calculation unit 401 and the image blur in the X-axis direction and the Y-axis direction calculated by the translational blur calculation unit 402.

[0170] In addition, the image blur correction optical system target position calculation unit 403 calculates the amount of image blur at the second position of the image plane 70 based on the image blur in the X-axis and Y-axis directions after the sum, the shooting magnification (calculated based on the position of the zoom optical system 31), and the distance from the camera 1A to the subject 80 (calculated based on the position of the focus optical system 32).

[0171] The blur correction optical system target position calculation unit 403 calculates a target position of the blur correction optical system 33 for moving the blur correction optical system 33 in a direction that cancels out the calculated amount of image blur, in order to operate the blur correction drive mechanism 37 of the interchangeable lens 3A to perform image blur correction. Then, the vibration reduction optical system target position calculation unit 403 sends a signal indicating the target position to the vibration reduction drive mechanism 37 of the interchangeable lens 3A.

[0172] Note that the image blur correction in the fifth embodiment includes correction in the Y-axis direction when the camera 1A rotates in the Pitch direction, and correction in the X-axis direction when the camera 1A rotates in the Yaw direction. The above formulas (1) and (2) represent the correction in the Y-axis direction when camera 1A is rotated in the Pitch direction. When camera 1A is rotated in the Yaw direction, the same correction as the above-mentioned correction is required in the X-axis direction. The correction in the Y-axis direction when camera 1A is rotated in the Pitch direction and the correction in the X-axis direction when camera 1A is rotated in the Yaw direction are the same except for the direction, so the explanation of the correction in the X-axis direction will be omitted.

[0173] Furthermore, when camera 1A rotates in both the pitch and yaw directions, image blurring occurs simultaneously in both the X and Y axes due to both rotational movements, so the image blurring caused by both rotational movements is added together with a positive or negative sign assigned to the direction of each of the X and Y axes, and then corrected in both the X and Y axes based on the image blurring after addition.

[0174] In the fifth embodiment, as in the fourth embodiment, the image blur calculated by the translational blur calculation unit 402 is treated as being approximately constant even if the position on the image plane 70 (the imaging plane of the image sensor 22) varies. The outline of the fifth embodiment is as follows. The angular shake calculation section 201 of the shake correction section 21a of the camera body 2A calculates the image shakes Δy1 and Δy2 at the first position (the center of the image plane 70) and the second position of the image plane 70. The blur correction unit 21a calculates a correction coefficient g, which is the ratio between the image blur Δy1 at the first position and the image blur Δy2 at the second position, and transmits information indicating the correction coefficient g to the blur correction unit 40 of the interchangeable lens 3A.

[0175] Angular shake calculation section 401 of image blur correction section 40 of interchangeable lens 3A calculates image blur at a first position (the center of image plane 70) on image plane 70. Angular shake calculation section 401 further calculates image blur at a second position on image plane 70 by multiplying the image blur at the first position by a correction coefficient g based on information received from camera body 2A by a receiving section. The translational shake calculation unit 402 of the shake correction unit 40 calculates the image shake at, for example, the first position. The shake correction optical system target position calculation unit 403 of the shake correction unit 40 performs an addition operation on the image shake at the second position and the image shake calculated by the translational shake calculation unit 402, assigning a positive or negative sign depending on the direction of each of the X and Y axes, and then calculates the amount of image shake at the second position on the image plane 70 based on the image shake in the X and Y axes after addition.

[0176] According to the fifth embodiment described above, the following effects can be obtained. (1) The image stabilization device includes an image sensor 22 that captures an object image formed on an image plane 70 by an interchangeable lens 3A, a CPU 21 that determines a position on the image plane 70, a blur correction unit 21a that calculates image blur Δy1 and image blur Δy2 at a first position (the center of the image plane 70) that is predetermined on the image plane 70, a second position determined by the CPU 21, and a blur detected by a blur sensor 31, and transmits a correction coefficient g, which is the ratio of the image blur Δy1 and the image blur Δy2, or information on the difference, to the interchangeable lens 3A. The interchangeable lens 3A includes a camera body 2A having a CPU 21, a blur correction optical system 33 that corrects blur, a blur correction unit 40 that calculates image blur Δy1 at a first position (the center of the image plane 70) of the image sensor 22 based on the first position (the center of the image plane 70) and shake detected by a shake sensor 39, the blur correction unit 40 that receives information from the camera body 2A, and a blur correction drive mechanism 37 that corrects the image blur Δy1 calculated by the blur correction unit 40 based on the received information and moves the blur correction optical system 33 in a direction that suppresses image blur after correction. This allows the blur correction unit 40 of the interchangeable lens 3A to appropriately suppress image blur, for example, at a second position determined by the CPU 21 of the camera body 2A. This is particularly suitable when the focal length f of the interchangeable lens 3A is short (or when the angle of view is wide due to the relationship between the size of the image sensor 22 and the focal length f).

[0177] (2) The image blur correction unit 21a of the camera body 2A calculates image blur Δy1 and image blur Δy2 based on the output of the shake sensor 31 and the focal length f of the interchangeable lens 3A, and the image blur correction unit 40 of the interchangeable lens 3A calculates image blur Δy1 based on the output of the shake sensor 39 and the focal length f. This allows the image blur correction unit 40 of the interchangeable lens 3A to appropriately calculate the image blur Δy2 at a second position other than the center of the image plane 70, and to appropriately suppress image blur based on this image blur Δy2.

[0178] The fifth embodiment may be combined with the fourth modification of the third embodiment described above. This embodiment shares with the fourth modification of the third embodiment that image blur correction is performed by operating both the blur correction drive mechanism 26 of the camera body 2A and the blur correction drive mechanism 37 of the interchangeable lens 3A. This embodiment also shares with the fifth embodiment that calculations are performed by both the blur correction unit 21a of the CPU 21 of the camera body 2A and the blur correction unit 40 of the interchangeable lens 3A.

[0179] For example, CPU 21 of camera body 2A transmits to image blur correction unit 40 of interchangeable lens 3A (a) information on a first position on image plane 70 where image blur is calculated, and (b) information indicating the ratio of image blur correction performed by interchangeable lens 3A to image blur correction performed by camera body 2A. Image blur correction unit 40 of interchangeable lens 3A calculates image blur at the first position on image plane 70, and then uses equation (6) above to determine the image blur V(L) to be shared by interchangeable lens 3A. On the other hand, the blur correction unit 21a of the camera body 2A calculates the angular blur at the first position of the image plane 70 and the image blur at the second position of the image plane 70, and then calculates the image blur V(B) shared by the camera body 2A using the above equation (7).

[0180] The blur correction unit 40 of the interchangeable lens 3A calculates the target position of the blur correction optical system 33 based on the calculated image blur V(L) and the image blur calculated by the translational blur calculation unit 402, and thereby operates the blur correction drive mechanism 37 of the interchangeable lens 3A to perform image blur correction. Furthermore, the blur correction unit 21a of the camera body 2A calculates the target position of the image sensor 22 based on the calculated image blur (B) and the image blur calculated by the translational blur calculation unit 202, thereby operating the blur correction drive mechanism 26 of the camera body 2A to perform image blur correction.

[0181] In the above-described embodiments and their modifications, image blur is corrected at a position where blur is desired to be eliminated. Therefore, while image blur is suppressed at a position determined by the CPU 21 on the image plane 70, it is conceivable that image blur may remain at other positions on the image plane 70. In such a case, image restoration using image processing may be combined. The CPU 21 sends an instruction to the signal processing circuit 27 to execute image restoration processing that makes image blur less noticeable by, for example, applying strong edge enhancement processing to the data corresponding to the other positions among the image data generated by the signal processing circuit 27. [Explanation of symbols]

[0182] 1, 1A... camera 2, 2A... camera body 3, 3A... interchangeable lens 21... CPU 21a, 40... shake correction unit 22... image sensor 26, 37... shake correction drive mechanism 31, 39... vibration sensor 33... shake correction optical system 70... image plane 80... subject

Claims

1. a detection unit that detects movement; a first correction element that moves in a direction intersecting an optical axis of an optical system that forms an image of a subject based on the movement detected by the detection unit; a first control unit that, when the detection unit detects rotation around the X-axis in a case where image blur at a position away from the center of the image by a predetermined distance is corrected, moves the first correction element in a direction having a Y-axis direction component orthogonal to the X-axis and the X-axis direction component, according to a position on the image plane where image blur is corrected, and moves the first correction element in the Y-axis direction; Equipped with when moving the first correction element in the direction having the Y-axis direction component, the first control unit increases the length by which the first correction element is moved as the position on the image plane at which image blur is corrected is farther from the center of the image. Image stabilization device.

2. 2. The image blur correction device according to claim 1, wherein, when a focal length of the optical system is longer than a predetermined length and the detection unit detects rotation about the X axis, the first control unit moves the first correction element in the Y axis direction regardless of a position on the image plane at which image blur is corrected.

3. The image blur correction device according to claim 1 , wherein the first correction element is a part of a lens included in the optical system.

4. 3. The image stabilization device according to claim 1, wherein the first correction element is an imaging element that captures the image formed by the optical system.

5. An interchangeable lens comprising the image stabilization device according to claim 3.

6. A camera system comprising the interchangeable lens according to claim 5 and a camera body.

7. A camera body comprising the image stabilization device according to claim 4.

8. A camera system comprising the camera body according to claim 7 and an interchangeable lens.

9. A camera system comprising the camera body according to claim 7 and an interchangeable lens, The interchangeable lens is a lens-side detector that detects movement; a lens that is part of the optical system included in the interchangeable lens and moves in a direction intersecting an optical axis of the optical system; a second control unit that moves the lens based on the movement detected by the lens side detection unit, A camera system in which the first control unit and the second control unit provided in the camera body share the responsibility of correcting image blur caused by movement applied to the camera system.

10. a second correction element that moves in a direction intersecting an optical axis of the optical system that forms the image, based on the movement detected by the detection unit; the first control unit moves the second correction element only in the Y-axis direction when the detection unit detects rotation around the X-axis; 3. The image stabilization device according to claim 1, wherein the first correction element and the second correction element share the responsibility of correcting image blur of the image caused by the movement detected by the detection unit.

Images