Control device, imaging device, lens device, camera system, control method, and program

Abstract

To provide a control device that can achieve good image blur correction with reduced eccentric aberration. [Solution] The control device is used in a camera system comprising a lens device having an optical system including first and second lenses for correcting image blur, and an imaging device having correction means for correcting image blur and to which the lens device is detachably attached, and the control device has setting means for setting the correction ratio of the first lens, the second lens, and the correction means so as to correct a first eccentric aberration with the first and second lenses and correct a second eccentric aberration different from the first eccentric aberration with the correction means.

Description

[Technical Field]

[0001] This invention relates to a control device. [Background technology]

[0002] There are two methods for correcting image blur caused by camera shake: optical image stabilization (OIS), which corrects the image optically, and electronic image stabilization (EIS), which corrects the image electronically. Optical image stabilization includes lens shift (OIS), which moves the image stabilization lens approximately perpendicular to the optical axis (eccentric), and sensor shift (IIS), which moves the image sensor approximately perpendicular to the optical axis.

[0003] Generally, when camera shake occurs in the yaw or pitch direction, image shift, trapezoidal distortion, and uneven focus occur. OIS can correct image shift and trapezoidal distortion, but it can cause eccentric aberrations such as eccentric chromatic aberration, eccentric coma aberration, eccentric astigmatism, eccentric field curvature, and eccentric distortion. IIS can correct image shift. EIS can correct trapezoidal distortion (tilt-shift) through homography transformation and image shift through image cropping.

[0004] Patent Document 1 discloses a method for obtaining good image stabilization performance against large camera shake as a whole camera system by appropriately setting the correction ratios for OIS and IIS. Patent Document 2 also discloses a method for obtaining good image stabilization performance against large camera shake as a whole camera system by appropriately setting the correction ratios for OIS, IIS, and EIS. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2015-141391 [Patent Document 2] Japanese Patent Publication No. 2021-166332 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, since the eccentricity caused by performing OIS cannot be corrected without performing another OIS, there is a risk that image blur may not be properly corrected.

[0007] The present invention aims to provide a control device capable of achieving good image blur correction with reduced eccentric aberration. [Means for solving the problem]

[0008] A control device as one aspect of the present invention is a control device used in a camera system comprising a lens device having an optical system including first and second lenses for correcting image blur, and an imaging device having correction means for correcting image blur and to which the lens device is detachably attached, characterized in that it has setting means for setting the correction ratio of the first lens, the second lens, and the correction means so as to correct a first eccentric aberration with the first and second lenses and correct a second eccentric aberration different from the first eccentric aberration with the correction means. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a control device that can achieve good image blur correction with reduced eccentric aberration. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram illustrating the configuration of an interchangeable lens camera system. [Figure 2] This is a block diagram showing the internal configuration of the image stabilization unit in an interchangeable lens camera system. [Figure 3] This is a conceptual diagram illustrating the image blur correction effect of each image blur correction unit. [Figure 4] This is a flowchart showing the control method for image blur correction in Example 1. [Figure 5]It is a conceptual diagram showing the stroke amounts of the image stabilization lens and the image sensor at the wide-angle side in Example 1. [Figure 6] It is a conceptual diagram showing the stroke amounts of the image stabilization lens and the image sensor at the telephoto side in Example 1. [Figure 7] It is a flowchart showing the image blur correction control method of Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, examples of the present invention will be described in detail with reference to the drawings. In each drawing, the same members are denoted by the same reference numerals, and overlapping descriptions are omitted.

[0012] Figure 1 is a configuration diagram of an interchangeable-lens camera system (hereinafter referred to as a camera system) according to an embodiment of the present invention. The camera system includes a camera body (imaging device) 200 and an interchangeable lens (lens device) 100 that is detachably attached to the camera body 200. The interchangeable lens 100 is configured to be capable of executing two OIS (a first OIS and a second OIS). The camera body 200 is configured to be capable of executing at least one of IIS and EIS. The interchangeable lens 100 and the camera body 200 communicate with each other via communication units 113 and 208 provided respectively therein.

[0013] The interchangeable lens 100 includes an imaging optical system 101, a zoom drive unit 107, an aperture stop drive unit 108, image stabilization drive units 109 and 110, a focus drive unit 111, a lens microcomputer (hereinafter referred to as a lens microcomputer) 112, and a storage unit 114. The imaging optical system 101 includes a zoom lens 102, an aperture stop 103, an image stabilization lens (first lens) 104, an image stabilization lens (second lens) 105, and a focus lens 106.

[0014] The zoom lens 102 changes the focal length of the imaging optical system 101, i.e., magnifies it, by moving in the optical axis direction of the imaging optical system 101 (in the direction of the arrow in Figure 1). The zoom drive unit 107 moves the zoom lens 102 in response to instructions from the lens microcontroller 112, which has acquired the position of the zoom lens 102 detected using a position sensor such as a potentiometer (not shown).

[0015] The aperture diaphragm 103 is equipped with aperture blades that change the aperture diameter in order to adjust the amount of light transmitted through the imaging optical system 101. The aperture diaphragm drive unit 108 changes the aperture diameter of the aperture diaphragm 103 by driving an actuator such as a stepping motor in response to instructions from the lens microcontroller 112, which has acquired the aperture diameter detected using a sensor such as a photointerrupter (not shown).

[0016] The vibration-damping lenses 104 and 105 correct image blur caused by movement (camera shake) applied to the camera system by moving in a direction perpendicular to the optical axis of the imaging optical system 101 (in the direction of the arrow in Figure 1). The vibration-damping drive units 109 and 110 detect the angular velocity of the yaw and pitch angular shake of the camera shake using, for example, a gyro sensor (not shown), and output a camera shake detection signal. The vibration-damping drive units 109 and 110 move the vibration-damping lenses 104 and 105 by driving actuators such as voice coil motors in response to instructions from the lens microcontroller 112, which has acquired the camera shake detection signal (angular velocity signal described later) and the OIS correction ratio. In this embodiment, the first OIS is performed by moving the vibration-damping lens 104 in a direction perpendicular to the optical axis of the imaging optical system 101, and the second OIS is performed by moving the vibration-damping lens 105 in a direction perpendicular to the optical axis of the imaging optical system 101.

[0017] The focus lens 106 adjusts the focusing distance of the imaging optical system 101 by moving in the direction of the optical axis of the imaging optical system 101. The focus drive unit 111 moves the focus lens 106 by driving an actuator such as a stepping motor in response to instructions from the lens microcontroller 112, which has acquired the position of the focus lens 106 detected using a position sensor such as an encoder (not shown).

[0018] The memory unit 114 is composed of ROM (Read Only Memory) and RAM (Random Access Memory), etc. The memory unit 114 stores optical information necessary for controlling the zoom lens 102, aperture diaphragm 103, image stabilization lenses 104 and 105, and focus lens 106. The optical information includes, for example, information on optical characteristics such as the movable stroke amount of the image stabilization lenses 104 and 105, sensitivity necessary for image blur correction, aberration coefficient, focal length, and object distance.

[0019] The camera body 200 includes an image sensor (correction means) 201, an image sensor drive unit 202, a signal processing unit 203, a recording processing unit 204, a display unit 205, an operation unit 206, a camera microcomputer (hereinafter referred to as camera microcomputer) 207, and a storage unit 209.

[0020] The image sensor 201 is a photoelectric conversion element composed of a CMOS (Complementary Metal-Oxide-Semiconductor) sensor or a CCD (Charge Coupled Device) sensor. The image sensor 201 performs photoelectric conversion (imaging) of the subject image (optical image) formed by the imaging optical system 101. In addition, the image sensor 201 corrects image blur caused by movement (camera shake) applied to the camera system by moving the image sensor 201 in a direction perpendicular to the optical axis of the imaging optical system 101. In other words, IIS is performed by moving the image sensor 201 in a direction perpendicular to the optical axis of the imaging optical system 101.

[0021] The image sensor drive unit 202, for example, uses a gyro sensor (not shown) to detect the angular velocity of yaw, pitch, and roll angular shakes among the camera shakes, and further uses an acceleration sensor (not shown) to detect shift shakes among the camera shakes, and outputs a camera shake detection signal. The image sensor drive unit 202 moves the image sensor 201 by driving an actuator such as a voice coil motor in response to instructions from the camera microcontroller 207, which has acquired the camera shake detection signal and the IIS correction ratio.

[0022] The signal processing unit 203 converts the analog imaging signal output from the image sensor 201 into a digital imaging signal. The signal processing unit 203 also performs various signal processing operations on the digital imaging signal, such as noise reduction and color correction, to generate video signals, focus signals, luminance signals, and color difference signals. The video signal output from the signal processing unit 203 is sent to the recording processing unit 204. The signal processing unit 203 generates still image data and video data from the video signal and performs EIS (Electronic Image Processing) operations such as cropping and homography conversion on the obtained still image data and video data. The signal processing unit 203 records the generated still image data and video data on a recording medium (not shown).

[0023] Furthermore, the focus signal output from the signal processing unit 203 is input to the camera microcontroller 207. The focus signal is, for example, a signal indicating the amount of defocus in phase-difference detection type focus detection. The camera microcontroller 207 converts the amount of defocus into the amount of drive of the focus lens 106 and transmits a focus command including this amount to the lens microcontroller 112. Based on the received focus command, the lens microcontroller 112 instructs the focus drive unit 111 to move the focus lens 106. This enables autofocus (AF).

[0024] Furthermore, the luminance signal output from the signal processing unit 203 is input to the camera microcontroller 207. The camera microcontroller 207 calculates the aperture value (F-number), shutter speed, and sensitivity of the image sensor 201 so that the brightness evaluation value obtained from the luminance signal is appropriate. The camera microcontroller 207 transmits an aperture command, including the aperture value, to the lens microcontroller 112. Based on the received aperture command, the lens microcontroller 112 instructs the aperture diaphragm drive unit 108 to change the aperture diameter of the aperture diaphragm 103. The camera microcontroller 207 also sets the shutter speed and sensitivity of the image sensor 201. This enables automatic exposure (AE).

[0025] The control unit 206 includes an imaging instruction switch (not shown) and switches for setting imaging conditions, etc.

[0026] The camera microcontroller 207 performs various controls in response to input from the operation unit 206.

[0027] Figure 2 is a block diagram showing the internal configuration of the image stabilization unit of the camera system. The image stabilization unit of the camera system includes a lens-side image stabilization unit 300 included in the lens microcontroller 112 and a camera-side image stabilization unit 400 included in the camera microcontroller 207.

[0028] The lens gyro offset removal unit 302 removes the offset component from the angular velocity signal output from the lens-side gyro sensor 301.

[0029] The lens-side angle conversion unit 303 converts the angular velocity signal output from the lens gyro offset removal unit 302 into an angle signal.

[0030] The lens-side gain-phase calculation unit 304 passes the angle signal through a phase-leading filter (PLF) and a phase-delay filter (PDF) in accordance with the characteristics of the lens-side gyro sensor 301 and lens actuators 309 and 310. In some cases, the signal may also be passed through a low-pass filter (LPF) and a high-pass filter (HPF) to correct low-frequency and high-frequency shake, respectively, using the first and second OIS.

[0031] The lens-side communication receiver 306 receives information regarding image blur correction transmitted from the camera-side communication transmitter 405 of the camera body 200.

[0032] The memory unit 114 stores information regarding optical characteristics such as the amount of stroke the OIS (Optical Image Stabilization) lenses 104 and 105 can move, the sensitivity required for image blur correction, aberration coefficients, focal length, and object distance. The memory unit 114 also stores information on the image blur correction angle when the image sensor 201 moves by a predetermined amount, i.e., camera image blur correction sensitivity (IIS optical information). Furthermore, the information stored in the memory unit 114 may be information that changes depending on the movement of the zoom lens 102 or the focus lens 106.

[0033] The lens-side coordinated control unit 307 performs coordinated control by executing two OIS and IIS based on the information in the memory unit 114 and the information received by the lens-side communication receiver unit 306. The lens-side coordinated control unit 307 can also pass information regarding image blur correction to the lens-side gain phase calculation unit 304. In addition, the lens-side coordinated control unit 307 acquires the correction ratio (sharing amount) to be corrected by the two OIS and IIS.

[0034] The vibration-damping lens control unit 308 generates control signals to move the vibration-damping lenses 104 and 105 via the lens actuators 309 and 310, based on the angle signal output from the lens-side gain phase calculation unit 304.

[0035] The camera gyro offset removal unit 402 removes the offset component from the angular velocity signal output from the camera-side gyro sensor 401.

[0036] The camera-side angle conversion unit 403 converts the angular velocity signal output from the camera gyro offset removal unit 402 into an angle signal.

[0037] The camera-side gain phase calculation unit 404 passes the angle signal through a phase-leading filter (PLF) and a phase-delay filter (PDF) in accordance with the characteristics of the camera-side gyro sensor 401 and image sensor actuator 409. In some cases, it may also pass the signal through a low-pass filter (LPF) or high-pass filter (HPF) for the purpose of correcting low-frequency or high-frequency shake with IIS.

[0038] The memory unit 209 stores information such as the amount of stroke the image sensor 201 can move using IIS, and transmits it to the lens microcontroller 112 via the camera-side communication transmission unit 405 as information within the camera body 200.

[0039] The camera-side communication receiver 406 receives information regarding image blur correction transmitted from the lens-side communication transmitter 305 of the interchangeable lens 100.

[0040] The camera-side coordinated control unit 407 determines the amount of shake to be corrected by IIS (image blur correction amount) based on the information in the memory unit 209 and the information received by the camera-side communication receiver unit 406 (correction ratio information and sensitivity information required for correction). The camera-side coordinated control unit 407 can also pass information regarding image blur correction to the camera-side gain phase calculation unit 404.

[0041] The image sensor control unit 408 uses the angle signal output from the camera-side gain phase calculation unit 404 and the output from the camera-side coordination control unit 407 to generate a control signal for moving the image sensor 201 via the image sensor actuator 409.

[0042] The electronic image stabilization (EMS) unit (correction means) 410 uses the angle signal output from the camera-side gain phase calculation unit 404 and the output from the camera-side coordinated control unit 407 to perform EIS such as cropping and homography conversion on the obtained still image data and video data.

[0043] The image blur correction in each embodiment will be described below. In each embodiment, the case in which the lens-side image blur correction unit 300 functions as a control device for controlling the image blur correction of the camera system will be described, but the camera-side image blur correction unit 400 may also function as the control device. [Examples]

[0044] This embodiment describes a method for performing image blur correction using two OIS and IIS.

[0045] First, the image blur correction effect of each image blur correction unit will be explained with reference to Figure 3. Figure 3 is a conceptual diagram showing the image blur correction effect of each image blur correction unit. Normally, camera shake causes image shift, trapezoidal distortion, and uneven focus, but for the sake of simplicity, uneven focus will be ignored here. Also, normally, OIS causes prism effect (image shift), eccentric chromatic aberration, eccentric coma aberration, eccentric astigmatism, eccentric field curvature, eccentric distortion, etc., but here, all but prism effect (image shift) and eccentric distortion will be ignored. Figure 3 shows the image blur correction effect in which eccentric distortion is preferentially corrected by the first OIS and second OIS, and image shift is corrected by IIS.

[0046] Figure 3(a) shows the deformation of a subject image when yaw-direction camera shake occurs, compared to a subject image without camera shake. In Figure 3(a), trapezoidal distortion and image shift in the positive z-axis direction occur due to camera shake. The movement of the subject image due to camera shake at the center and corners is illustrated by arrows.

[0047] Figure 3(b) shows the deformation of the subject image when the first OIS is applied to a subject image (Figure 3(a)) that has been deformed by camera shake. In Figure 3(b), the trapezoidal distortion and image shift caused by camera shake are overcorrected by the first OIS, which generates eccentric distortion and an image shift in the negative z-axis direction. The movement of the subject image due to the first OIS at the center and the four corners is illustrated by arrows.

[0048] Figure 3(c) shows the deformation of the subject image that occurs when the second OIS is applied to the subject image that has been overcorrected by the first OIS (Figure 3(b)). In Figure 3(c), the overcorrected eccentric distortion is corrected by generating eccentric distortion with the second OIS, and the overcorrected image shift is overcorrected by generating an image shift in the positive z-axis direction with the second OIS. The movement caused by the second OIS at the center and four corners of the subject image is illustrated by arrows.

[0049] Figure 3(d) shows the deformation of the subject image that occurs when IIS is applied to the subject image that has been overcorrected by the second OIS (Figure 3(c)). In Figure 3(d), the overcorrected image shift is corrected by generating an image shift in the negative z-axis direction using IIS. The movement of the subject image center due to IIS is illustrated by arrows.

[0050] Figure 4 is a flowchart showing the control method for image stabilization in this embodiment. When power is supplied to the interchangeable lens 100 and the camera body 200, the lens-side image stabilization unit 300 and the camera-side image stabilization unit 400 start operating. The flow in Figure 4 may be performed continuously after power is supplied to the camera system, or it may be performed only during periods when imaging with recording is taking place. That is, during periods when imaging with recording is not taking place, only IIS or OIS may be performed, or image stabilization may be stopped.

[0051] In step S100, the lens-side image stabilization unit 300 shares information with the camera-side image stabilization unit 400 and the interchangeable lens 100 and camera body 200 through communication via the respective communication transmitters and receivers of the interchangeable lens 100 and camera body 200. The shared information includes the amount of stroke that the image sensor 201 and the image stabilization lenses 104 and 105 can move in IIS and OIS, and information on optical characteristics such as sensitivity, aberration coefficient, focal length, and object distance required for image stabilization. This step may be performed when the camera system is started up or may be performed periodically.

[0052] In step S101, the lens-side image blur correction unit 300 determines whether the imaging optical system 101 is a wide-angle lens or not, based on the information shared in step S100. Specifically, it determines this by whether the focal length of the imaging optical system 101 is shorter than a predetermined value (for example, 20mm or 24mm). If the lens-side image blur correction unit 300 determines that the imaging optical system 101 is a wide-angle lens, it executes the process in step S102; otherwise, it executes the process in step S104.

[0053] In this step, we determined whether the imaging optical system 101 is a wide-angle lens or not, but the determination may also be made based on the focusing distance of the imaging optical system 101. Specifically, the determination may be made based on whether the focusing distance is longer than a predetermined value (for example, any of 30cm to 50cm in 35mm equivalent). In this case, if the lens-side image blur correction unit 300 determines that the focusing distance is longer than the predetermined value, it should execute the process in step S102, and if it determines that it is not, it should execute the process in step S104.

[0054] In step S102, the lens-side image stabilization unit 300 obtains the correction ratio A of the first OIS, the correction ratio B of the second OIS, and the correction ratio C of the IIS relative to the image stabilization amount of the entire camera system, based on the information shared in step S100. Specifically, the correction ratios A, B, and C are the correction ratios of the image stabilization lenses 104 and 105 and the image sensor 201, respectively. The correction ratios A, B, and C may be set between 0 and 1, or they may be set to 0 or less in the case of overcorrection. The correction ratios A, B, and C may be calculated by the lens-side image stabilization unit 300 and the camera-side image stabilization unit 400 respectively, or they may be calculated by either the lens-side image stabilization unit 300 or the camera-side image stabilization unit 400 and shared via communication. In this step, it is preferable to set the correction ratios so that eccentric distortion aberration is corrected by the first and second OIS. Furthermore, it is preferable to set the absolute value of the correction ratio of one of the image-stabilizing lenses 104 and 105, which has higher sensitivity (a larger amount of image blur correction relative to the amount of movement), to be greater than the absolute value of the correction ratio of the other lens. In this embodiment, the lens-side image blur correction unit 300 functions as a setting means for setting correction ratios A, B, and C.

[0055] The total image blur correction amount for the camera system may be calculated based on the angular velocity signals output from the lens-side gyro sensor 301 and the camera-side gyro sensor 401 by the lens-side image blur correction unit 300 and the camera-side image blur correction unit 400, respectively. The angular velocity signals output from the lens-side gyro sensor 301 and the camera-side gyro sensor 401 may be shared via communication. Alternatively, the angular velocity signals may be converted into angle signals or image blur correction amounts, shared via communication, and used in place of the angular velocity signals.

[0056] In step S103, the lens-side image blur correction unit 300 performs a first OIS with correction ratio A, a second OIS with correction ratio B, and an IIS with correction ratio C.

[0057] In step S104, the lens-side image blur correction unit 300 detects (acquires) low-frequency blur and high-frequency blur by passing the angular velocity signal output from the lens-side gyro sensor 301 through an LPF, HPF, etc.

[0058] In step S105, the lens-side image blur correction unit 300 obtains the correction ratio A of the first OIS, the correction ratio B of the second OIS, and the correction ratio C of the IIS relative to the image blur correction amount of the entire camera system, based on the information shared in step S100. For example, consider the case where low-frequency blur is corrected with the first OIS, high-frequency blur is corrected with the second OIS, and blur across the entire frequency band is corrected with the IIS. In this case, after appropriately calculating the correction ratio X for correcting blur across the entire frequency band by the two OIS as a whole and the correction ratio C for correcting blur across the entire frequency band by the IIS, the correction ratios A and B are appropriately calculated from the correction ratio X according to the amount of low-frequency and high-frequency blur. In addition, in this step, it is preferable to set the correction ratios so that eccentric coma aberration is corrected by the first and second OIS. Furthermore, one of the low-frequency blur and the high-frequency blur is the blur in the first frequency band, and the other is the blur in the second frequency band. Low-frequency vibrations and high-frequency vibrations may overlap with each other, at least in part.

[0059] In step S106, the lens-side image blur correction unit 300 performs a first OIS with correction ratio A, a second OIS with correction ratio B, and an IIS with correction ratio C.

[0060] In step S107, the lens-side image stabilization unit 300 determines whether to stop image stabilization. If the lens-side image stabilization unit 300 determines to stop image stabilization, it terminates this flow; otherwise, it executes the process in step S101.

[0061] Here, we will explain how to calculate the correction ratios for the first OIS, the second OIS, and IIS. (1) Impact of OIS alone First, the effect of eccentricity in OIS alone will be described. When the image stabilization lenses 104 and 105 are eccentric, eccentric aberrations such as prism effect, eccentric chromatic aberration, eccentric coma, eccentric astigmatism, eccentric field curvature, and eccentric distortion occur. Let the optical axis be X, and YZ coordinates are taken in a plane perpendicular to the optical axis. To simplify the description herein, the eccentric direction (i.e., the shift direction of the image stabilization lenses 104 and 105) is assumed to be the Y-axis direction, and the shift amount is E OIS . The evaluation direction is assumed to be any direction in the YZ plane, and the azimuth angle formed between it and the Y-axis is φ ω . Let the ideal image height be Y', and the numerical aperture be NA. Let the image stabilization aberration coefficient for the first-order prism effect be ΔE. Let the image stabilization aberration coefficient for first-order eccentric chromatic aberration be ΔcE. Let the image stabilization aberration coefficient for first-order eccentric coma be II E1 . Let the image stabilization aberration coefficients for first-order and second-order eccentric astigmatism be III E1 , III E2 respectively. Let the image stabilization aberration coefficients for first-order and second-order eccentric field curvature be P E1 , P E2 respectively. Let the image stabilization aberration coefficients for first-order and second-order eccentric distortion be V E11 , V E12 respectively. Let the image stabilization aberration coefficients for first-order and second-order additional eccentric distortion aberrations be V E21 , V E22 respectively.

[0062] The effects of the prism effect of OIS in the Y-axis direction and Z-axis direction do not depend on the image height, and are expressed by the following formulas.

[0063]

Math

[0064]

Math

[0065] Further, the effects of eccentric distortion of OIS in the Y-axis direction and Z-axis direction depend on the image height, and are expressed by the following formulas.

[0066]

Math

[0067]

number

[0068] Here, we have discussed prism action and eccentric distortion, ignoring other eccentric aberrations such as eccentric chromatic aberration, eccentric coma aberration, eccentric astigmatism, and eccentric field curvature. However, all of these eccentric aberrations may be considered in the same way. (2) Impact of IIS alone Next, we will explain the effects of eccentricity in the IIS alone. When the image sensor 201 is eccentric, only image shift occurs. For the sake of simplicity, we will consider the direction of eccentricity (i.e., the direction of shift of the image sensor 201) to be the Y-axis direction, and the amount of that shift is E IIS Let's assume that.

[0069] The effects of IIS image shift on the Y-axis and Z-axis directions are independent of image height and are expressed by the following equations (1) and (2).

[0070]

number

[0071]

number

[0072] (3) Effects of camera shake Furthermore, the effects of camera shake in the yaw and pitch directions will be explained. When rotational shake occurs in the yaw or pitch directions, image shift, trapezoidal distortion, and uneven blurring occur. Although details are omitted, the effect of camera shake in the yaw and pitch directions on the Y-axis direction ΔY is expressed as a variable, with the angular velocity signal detected by the gyro sensor or an equivalent quantity. blur , and the influence on the Z-axis direction ΔZ blur This can be expressed by a formula that depends on the image height. (4) Setting of correction ratio considering all effects From the above, the influence ΔY from the first OIS is OIS1 ,ΔZ OIS1 , the effect of the second OIS is ΔY OIS2 ,ΔZ OIS2 Therefore, the influence of camera shake and the two OIS and IIS on the Y-axis and Z-axis at a certain image height can be expressed by the following equation.

[0073]

number

[0074]

number

[0075] The shift amounts E of the first OIS, second OIS, and IIS are set to minimize this value in the central and peripheral image heights. OIS1 ,E OIS2 ,E IIS Set the parameters and determine the correction ratios A, B, and C. Here, we have mentioned the central and peripheral image heights, but other image heights may also be used. Furthermore, instead of using the strict calculation formulas described above, you may use equivalent approximation formulas or functions. In addition, we used the YZ Cartesian coordinate system, but polar coordinates may also be used. Moreover, if the stroke amount is large in a particular OIS, you may set a correction ratio that takes this into account.

[0076] The stroke amounts of the image stabilization lenses 104, 105 and the image sensor 201 at the wide-angle end will be explained below with reference to Figure 5. Figure 5 is a conceptual diagram showing the stroke amounts of the image stabilization lenses 104, 105 and the image sensor 201 at the wide-angle end. The two OIS and IIS are performed at the same frequency and phase, respectively. However, their amplitudes do not necessarily have to match.

[0077] Figure 5(a) shows the stroke amount of the vibration-damping lens 104 in the first OIS.

[0078] Figure 5(b) shows the stroke amount of the image stabilization lens 105 in the second OIS. Here, for example, in order to correct trapezoidal distortion caused by camera shake and eccentric distortion aberration caused by the first OIS with the second OIS, the image stabilization lens 105 is moved in the opposite direction to the image stabilization lens 104.

[0079] Figure 5(c) shows the stroke amount of the image sensor 201 in IIS. Here, for example, in order to correct camera shake, the first OIS, and the second OIS with IIS, the image sensor 201 is moved in the same direction as the image stabilization lens 104 and in the opposite direction to the image stabilization lens 105.

[0080] In order to correct the eccentricity aberration generated by the first OIS with the second OIS, the image stabilization lens 105 is moved in the opposite direction to the movement of the image stabilization lens 104, but this is not always the case. For example, if the focal lengths of the image stabilization lenses 104 and 105 have opposite signs, or if there is an aperture diaphragm between the image stabilization lenses 104 and 105, the eccentricity aberration generated by the first OIS can sometimes be corrected by the second OIS by moving the image stabilization lens 105 in the same direction as the image stabilization lens 104.

[0081] Next, with reference to Figure 6, the stroke amounts of the image stabilization lenses 104, 105 and the image sensor 201 at the telephoto end will be explained. Figure 6 is a conceptual diagram showing the stroke amounts of the image stabilization lenses 104, 105 and the image sensor 201 at the telephoto end.

[0082] Figure 6(a) shows the stroke amount of the image stabilization lens 104 in the first OIS. Here, for example, in order to correct a portion of the low-frequency vibration of camera shake with the first OIS, the image stabilization lens 104 is moved at a low frequency.

[0083] Figure 6(b) shows the stroke amount of the image stabilization lens 105 in the second OIS. Here, for example, the image stabilization lens 105 is moved at a high frequency in order to correct a portion of the high-frequency camera shake with the second OIS.

[0084] Figure 6(c) shows the stroke amount of the image sensor 201 in IIS. Here, for example, the image sensor 201 is moved in order to correct a portion of the camera shake across the entire frequency band using IIS.

[0085] In this case, OIS and IIS share the responsibility of correcting image stabilization across the entire frequency band, and the two OIS units share the responsibility of correcting image stabilization across the high and low frequency bands. However, this is not necessarily the only way to do so. For example, the first OIS could correct the high-frequency band of camera shake, and the second OIS and IIS could share the responsibility of correcting the low-frequency band of camera shake. [Examples]

[0086] This embodiment describes a method for correcting image blur using two OIS and EIS.

[0087] Figure 7 is a flowchart showing the control method for image blur correction in this embodiment.

[0088] In step S200, the lens-side image stabilization unit 300 shares information with the camera-side image stabilization unit 400 and the interchangeable lens 100 and camera body 200 through communication via the respective communication transmitters and receivers of the interchangeable lens 100 and camera body 200. The shared information includes the amount of stroke that the image stabilization lenses 104 and 105 can move in OIS, and information such as the sensitivity, focal length, and object distance required for image stabilization. This step may be performed when the camera system is started up or may be performed periodically.

[0089] In step S201, the lens-side image blur correction unit 300 obtains the correction ratio A of the first OIS, the correction ratio B of the second OIS, and the correction ratio C of the EIS relative to the image blur correction amount of the entire camera system, based on the information shared in step S100. The EIS can correct image shift and trapezoidal distortion, and its influence ΔY in the Y-axis and Z-axis directions. EIS ,ΔZ EISThese are expressed by equations (1) and (2) above, respectively. The effects of camera shake, the two OISs, and EIS on the Y-axis and Z-axis at a certain image height are expressed by the following equations.

[0090]

number

[0091]

number

[0092] The shift amounts E of the first OIS, second OIS, and EIS are set to minimize this value in the central and peripheral image heights. OIS1 ,E OIS2 ,E EIS Set the parameters and determine their correction ratios A, B, and C.

[0093] In step S202, the lens-side image blur correction unit 300 performs a first OIS with correction ratio A and a second OIS with correction ratio B.

[0094] In step S203, the lens-side image blur correction unit 300 performs EIS (Electronic Image Stabilization) such as homography conversion and cropping based on the correction ratio C.

[0095] In step S204, the lens-side image stabilization unit 300 determines whether to stop image stabilization. If the lens-side image stabilization unit 300 determines to stop image stabilization, it terminates this flow; otherwise, it executes the process in step S201. [Other examples] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0096] This embodiment includes the following configurations and methods. (Composition 1) A control device used in a camera system comprising a lens device having an optical system including first and second lenses for correcting image blur, and an imaging device having correction means for correcting image blur and to which the lens device is detachably attached, A control device characterized by having a setting means for setting the correction ratio of the first lens, the second lens, and the correction means so as to correct a first eccentricity aberration with the first and second lenses and correct a second eccentricity aberration different from the first eccentricity aberration with the correction means. (Configuration 2) The control device according to configuration 1, characterized in that the setting means sets the correction ratio according to the focusing distance of the optical system. (Composition 3) The control device according to configuration 1 or 2, characterized in that the setting means sets the correction ratio according to the focal length of the optical system. (Composition 4) The control device according to configuration 3, characterized in that the first eccentricity aberration is changed according to the focal length. (Composition 5) The control device according to configuration 4, characterized in that when the focal length is shorter than a predetermined value, the first eccentric aberration is an eccentric distortion aberration. (Composition 6) The control device according to configuration 4 or 5, characterized in that when the focal length is longer than a predetermined value, the first eccentric aberration is an eccentric coma aberration. (Composition 7) The control device according to any one of configurations 1 to 6, characterized in that the correction means is an image sensor. (Composition 8) The control device according to any one of configurations 1 to 7, characterized in that the correction means performs image blur correction by processing an image based on the image formed by the optical system. (Composition 9) The control device according to any one of configurations 1 to 8, characterized in that the second eccentric aberration is an image shift. (Composition 10) The first lens has a greater image blur correction amount relative to the amount of movement than the second lens. The control device according to any one of configurations 1 to 9, characterized in that the setting means sets the correction ratio such that the absolute value of the correction ratio of the first lens is greater than the absolute value of the correction ratio of the second lens. (Composition 11) The control device according to any one of configurations 1 to 10, characterized in that the setting means sets the correction ratio such that the first lens corrects blur in a first frequency band of the blur applied to the camera system, and the second lens corrects blur in a second frequency band that is at least partially different from the first frequency band. (Composition 12) A control device described in any one of configurations 1 to 11, An imaging device characterized by having an image sensor. (Composition 13) A control device described in any one of configurations 1 to 11, A lens device characterized by having an optical system. (Composition 14) A control device described in any one of configurations 1 to 11, Image sensor and A camera system characterized by having an optical system. (Method 1) A control method used in a camera system comprising a lens device having an optical system including first and second lenses for image blur correction, and an imaging device having correction means for image blur correction and to which the lens device is detachably attached, A control method characterized by having the steps of correcting a first eccentricity aberration with the first and second lenses, and setting the correction ratio of the first lens, the second lens, and the correction means so as to correct a second eccentricity aberration different from the first eccentricity aberration with the correction means. (Composition 15) A program characterized by causing a computer to execute the control method described in Method 1.

[0097] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist. [Explanation of symbols]

[0098] 100 interchangeable lenses (lens assembly) 101 Imaging optical system (optical system) 104 Image stabilizing lens (first lens) 105 Image stabilization lens (second lens) 200 Camera body (imaging device) 201 Image sensor (correction means) 300 Lens-side image blur correction unit (control device, setting means) 400 Camera-side image blur correction unit (control device, setting means) 410 Electronic vibration damping correction unit (correction means)

Claims

1. A control device used in a camera system comprising a lens device having an optical system including first and second lenses for correcting image blur, and an imaging device having correction means for correcting image blur and to which the lens device is detachably attached, A control device characterized by having a setting means for setting the correction ratio of the first lens, the second lens, and the correction means so as to correct a first eccentricity aberration with the first and second lenses and correct a second eccentricity aberration different from the first eccentricity aberration with the correction means.

2. The control device according to claim 1, characterized in that the setting means sets the correction ratio according to the focusing distance of the optical system.

3. The control device according to claim 1 or 2, characterized in that the setting means sets the correction ratio according to the focal length of the optical system.

4. The control device according to claim 3, characterized in that the first eccentricity aberration is changed according to the focal length.

5. The control device according to claim 4, characterized in that when the focal length is shorter than a predetermined value, the first eccentric aberration is an eccentric distortion aberration.

6. The control device according to claim 4, characterized in that when the focal length is longer than a predetermined value, the first eccentric aberration is an eccentric coma aberration.

7. The control device according to claim 1 or 2, characterized in that the correction means is an image sensor.

8. The control device according to claim 1 or 2, characterized in that the correction means performs image blur correction by processing an image based on the image formed by the optical system.

9. The control device according to claim 1 or 2, characterized in that the second eccentric aberration is an image shift.

10. The first lens has a greater image blur correction amount relative to the amount of movement than the second lens. The control device according to claim 1 or 2, characterized in that the setting means sets the correction ratio such that the absolute value of the correction ratio of the first lens is greater than the absolute value of the correction ratio of the second lens.

11. The control device according to claim 1 or 2, characterized in that the setting means sets the correction ratio such that the first lens corrects blur in a first frequency band of the blur applied to the camera system, and the second lens corrects blur in a second frequency band that is at least partially different from the first frequency band.

12. A control device according to claim 1 or 2, An imaging device characterized by having an image sensor.

13. A control device according to claim 1 or 2, A lens device characterized by having an optical system.

14. A control device according to claim 1 or 2, Image sensor and A camera system characterized by having an optical system.

15. A control method used in a camera system comprising a lens device having an optical system including first and second lenses for correcting image blur, and an imaging device having correction means for correcting image blur and to which the lens device is detachably attached, A control method characterized by having the steps of: correcting a first eccentricity aberration with the first and second lenses, and setting the correction ratio of the first lens, the second lens, and the correction means so as to correct a second eccentricity aberration different from the first eccentricity aberration with the correction means.

16. A program characterized by causing a computer to execute the control method described in claim 15.

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