Imaging device

Abstract

To provide a control unit that controls camera shake correction to reduce the influence of a shake remaining in a peripheral part.SOLUTION: A control unit comprises: selection means that selects a driving mode of first image shake correction means for moving an optical element and second image shake correction means for moving an image pickup device based on information indicating a focal distance; and drive control means that drives the first and second image shake correction means in the selected driving mode. The selection means selects a first driving mode when the focal distance is a first value and selects a second driving mode when the focal distance is a second value longer than the first value. When the first driving mode is selected, if a shake amount is equal to or less than a threshold, the drive control means performs drive control to drive the first image shake correction means based on the shake amount. When the second driving mode is selected, the drive control means performs drive control to drive the first and second image shake correction means to drive based on the shake amount and a predetermined drive ratio.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an image pickup apparatus, and more particularly to an image pickup apparatus having means for controlling the driving of an image pickup element and a photographing optical system for image blur correction. [Background technology]

[0002] In a digital camera system, as shown in Patent Document 1, for example, a technology is disclosed in which image blur correction means are provided in both the camera body and the lens device, and these are used to prevent degradation of image quality caused by shake applied to the camera body. According to this, a camera-side image blur correction means provided in the camera body moves an image sensor in a plane perpendicular to the optical axis based on the amount of shake applied to the camera body. This makes it possible to obtain a large image blur correction angle that cannot be obtained by simply moving a correction optical system (a blur correction lens group), which is a part of the photographing optical system, in a plane perpendicular to the optical axis, and makes it possible to handle larger shake. In this specification, the correction angle refers to the shake angle that can be corrected by the image blur correction means. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-141391 A Summary of the Invention [Problem to be solved by the invention]

[0004] In general, in a camera system such as that of Patent Document 1, when the focal length of the photographing optical system of the lens device is short and the lens device is a so-called wide-angle lens, the image blur correction angle of the camera-side image blur correction means that drives the image sensor is larger than when the focal length is long. However, when the lens device is wide-angle, when the image sensor is moved by the camera-side image blur correction means, a difference may occur in the appropriate image blur correction amount between the center of the image sensor (the position where the light passing through the optical axis is incident) and the peripheral portion (the area away from the optical axis). As a result, the inventors of the present invention have clarified that even if the deterioration of image quality due to the influence of image blur is reduced in the center, the reduction is limited in the peripheral portion. This point will be described in detail with reference to FIG. 6.

[0005] FIG. 6 shows that the camera-side image blur correction means moves the image sensor 901 from the position indicated by the dotted line by a distance d 10 This is a schematic diagram showing a state in which the image sensor 901 has been moved upward by a distance d in response to the entire camera system being rotated by an amount θ due to shaking. 10 However, since the focal length f of the photographing optical system 902 shown in FIG. 6 is short, it can be seen that the amount of movement of the image generated by the same rotation θ does not match between the center and the periphery. More specifically, when the entire camera system is rotated by θ, the amount of movement of the subject image at the center of the image sensor is d 10 However, in the peripheral area, the amount of movement of the subject image is d 10 +δ. Therefore, when the camera system rotates θ, the image sensor 901 is rotated by d 10 When moving the lens, the image blurs in the center (=d 10 ) can be eliminated, image blur (=d 10 The difference (δ) in the amount of movement of the subject image between the center and the periphery varies depending on the characteristics of the photographing optical system 902.

[0006] The present invention aims to provide a control device that controls at least one of a lens device, an imaging device, and a camera system so as to reduce the effect of blurring remaining in the peripheral areas even when there is a large difference in the amount of movement of the subject image between the center and the periphery. [Means for solving the problem]

[0007] A control device according to one aspect of the present invention is a control device that controls driving of a first image blur correction means that changes the direction of an optical axis of an image capturing optical system by moving an optical element included in the image capturing optical system, and a second image blur correction means that moves an image sensor that captures an object image formed by light transmitted through the image capturing optical system, in a plane perpendicular to the optical axis, and includes: a selection means that acquires information indicating a focal length of the image capturing optical system, and selects a drive mode of the first image blur correction means and the second image blur correction means based on the information indicating the focal length; and a drive control means for driving the first image blur correction means and the second image blur correction means in a drive mode selected by the selection means, the selection means selecting a first drive mode when the focal length is a first value, and selecting a second drive mode different from the first drive mode when the focal length is a second value longer than the first value, the drive control means controlling the drive so that the first image blur correction means is driven based on the shake amount when the first drive mode is selected and the shake amount of the imaging device including the imaging element is equal to or less than a first threshold value, controlling the drive so that the first image blur correction means and the second image blur correction means are driven based on the shake amount when the shake amount is greater than the first threshold value, and controlling the drive so that the first image blur correction means and the second image blur correction control means are driven based on the shake amount when the second drive mode is selected. Other aspects of the present invention will be made clear in the embodiments described below. Effect of the Invention

[0008] According to the present invention, it is possible to provide a control device that controls at least one of a lens device, an imaging device, and a camera system so as to reduce the influence of blurring that remains in the peripheral area when the focal length is short. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic conceptual diagram illustrating the configuration of a camera system 1000. [Diagram 2] 1 is a flow diagram for explaining an image shake correction operation performed by the camera system 1000 under the control of the camera body 1. FIG. [Diagram 3] 10 is a flow diagram for explaining lens side priority drive control that is implemented by the camera system 1000 under the control of the camera body 1. FIG. [Figure 4] 1 is a flow diagram for explaining cooperative control that the camera system 1000 implements under the control of the camera body 1. FIG. [Diagram 5] 1 is a schematic conceptual diagram for explaining an image blur correction operation performed by the camera system 1000 under the control of the camera body 1. FIG. [Figure 6] 10A and 10B are schematic conceptual diagrams illustrating differences in image blur amounts according to image heights. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A control device according to one aspect of the present invention is a control device that controls driving of a first image blur correction means that changes the direction of an optical axis of a photographing optical system by moving an optical element included in the photographing optical system, and a second image blur correction means that moves an image sensor that captures an object image formed by light transmitted through the photographing optical system, in a plane perpendicular to the optical axis, and obtains information indicating a focal length of the photographing optical system, and controls the first image blur correction means and the second image blur correction means based on the information indicating the focal length. Image stabilization using and a drive control means for driving the first image blur correction means and the second image blur correction means in the drive mode selected by the selection means, Less than a given valueWhen the focal length is a first value, a first driving mode is selected, and the focal length is Not less than the predetermined value When the second value is set, the first driving mode is set. What is a second driving mode different from the first driving mode, and the drive control means, when the first driving mode is selected, controls the drive so that the first image blur correction means drives based on the amount of shake when the amount of shake of the imaging device including the imaging element is equal to or smaller than a first threshold value, and controls the drive so that the first image blur correction means and the second image blur correction means drive based on the amount of shake when the amount of shake is greater than the first threshold value, and when the second driving mode is selected, controls the drive so that the first image blur correction means and the second image blur correction means drive based on the amount of shake. Right hand The step is the deflection amount and Determined before exposure begins The drive control is performed so as to drive the vehicle based on a predetermined drive ratio. Other aspects of the present invention will become apparent from the embodiments described below.

[0011] 1 is a schematic diagram illustrating the configuration of an image pickup system 1000 according to this embodiment. FIG. 1(a) is a central cross-sectional view of the image pickup system 1000, and FIG.

[0012] As shown in FIGS. 1(a) and 1(b), the imaging system 1000 of this embodiment includes a camera body 1 and a lens device 2 that can be attached to the camera body 1. The lens device 2 has a photographing optical system 3 consisting of a plurality of lenses, including an image blur correction optical system 19. The dotted line 4 indicates the optical axis of the photographing optical system 3. The camera body 1 also has an image sensor 6 and a camera-side image blur correction unit 7 that corrects image blur by moving the image sensor 6 in a plane perpendicular to the optical axis. The imaging system 1000 is a so-called lens-interchangeable single-lens camera, and is configured to allow various interchangeable lenses to be attached and detached via a circular mount block 5. The mount block 5 has electrical contacts 12, and the lens device 2 is attached to the camera body 1 via the mount block 5, so that the lens device 2 and the camera body 1 are connected to be able to communicate with each other. In this embodiment, a lens-interchangeable single-lens camera will be described as an example, but the present invention is not limited to this, and the present invention can also be applied to a system that is not a lens-interchangeable system.

[0013] 1(b) is a block diagram showing a schematic configuration of an imaging system 1000. In the imaging system 1000, light rays from an imaging angle of view centered on an optical axis 4 of an imaging optical system 3 of a lens device 2 pass through the imaging optical system 3 and are focused as a subject image on an imaging element 6 disposed in a camera body 1. The subject image is photoelectrically converted in a photoelectric conversion section (not shown) of the imaging element 6, and is converted into an electrical signal and transmitted to an image processing section 10. In the image processing section 10, the image signal is converted into an image file format through development processing, gamma processing, etc., and is stored in a non-volatile memory (not shown) by a camera control section 8.

[0014] The imaging element 6 arranged in the camera body 1 is configured to be movable in a plane perpendicular to the optical axis 4 by the camera side image blur correction unit 7. The camera side image blur correction unit 7 has a support unit and an actuator that supports the imaging element, and moves the imaging element in a plane perpendicular to the optical axis by driving the actuator. The camera side image blur correction control unit 9 performs camera side image blur correction by controlling the camera side image blur correction unit 7 under the control of the camera control unit 8. In addition, the image blur correction optical system 19, which is a part of the photographing optical system 3 of the lens device 2, is configured to be movable in a plane perpendicular to the optical axis 4 by the lens side image blur correction control unit 16 and the lens side image blur correction unit 15. The camera side image blur correction unit 15 has a support unit and an actuator that supports the correction optical system 19, and moves the correction optical system 19 in a plane perpendicular to the optical axis by driving the actuator. The lens side image blur correction control unit 16 performs lens side image blur correction by controlling the lens side image blur correction unit 15 under the control of the lens control unit 13.

[0015] The camera control unit 8 and the lens control unit 13 cooperate by communicating via the electrical contacts 12, and perform drive control to reduce unnecessary vibrations applied to the imaging system 1000 using the camera side image blur correction unit 7 and the lens side image blur correction unit 15, respectively. Note that in this embodiment, an example will be described in which the camera control unit 8 transmits an instruction to the lens control unit 13 and controls the lens side image blur correction control unit 16 and the lens side image blur correction unit 15 via the lens control unit 13, thereby controlling image blur correction of the entire imaging system 1000.

[0016] The lens side memory unit 14 stores the current focal length information and distortion information of the lens device 2, the image blur correction angle that can be controlled by the lens side image blur correction unit 15 (corresponding to the movable range of the correction optical system 19), and the like. The focal length information, distortion information, and the image blur correction angle of the lens side image blur correction unit 15 are referenced by the lens control unit 13, and also by the camera control unit 8 disposed in the camera body 1 via the electrical contacts 12. The camera control unit 8 issues a command regarding the drive control of the camera side image blur correction unit 7 to the camera side image blur correction control unit 9 based on the received focal length information, distortion information, and the controllable image blur correction angle of the lens side image blur correction unit 15. For example, the camera control unit 8 calculates the image blur correction angle that can be controlled by the camera side image blur correction unit 7 based on the focal length, and determines the drive amount ratio of the two image blur correction means together with the lens control unit. Also, for example, the camera control unit 8 also switches the method of determining the drive amount ratio of the two image blur correction means based on the distortion information. The method of controlling the image blur correction means by using this distortion information will be described in detail later.

[0017] The lens control unit 13 drives and controls various control means via various control units (not shown) in response to instructions given from the camera body 1. For example, in response to focus detection information and photometry information of a subject obtained by the image processing unit 10, the lens control unit 13 drives and controls focus adjustment means and aperture means (not shown) via a focus adjustment control unit and an aperture control unit (not shown) to adjust the imaging state of the subject image and the aperture state.

[0018] 2 to 4 are flow diagrams for explaining the image blur correction operation executed by the imaging system 1000. As described above, the image blur correction operation executed by the imaging system 1000 is performed by the camera control unit 8 determining the control amounts of the two image blur correction control units based on information stored in the lens side storage unit 14 while communicating with the lens control unit 13 via the electrical contacts 12. This flow is composed of the overall image blur correction operation flow shown in FIG. 2 and flows for explaining subroutines called "lens side priority control (first driving mode)" and "cooperative control (second driving mode)" in FIG. 2 (FIG. 3 and FIG. 4, respectively).

[0019] The flow of the entire image blur correction operation shown in FIG. 2 starts when the imaging system 1000 is turned on or when the imaging system 1000 returns from a sleep state. First, in step S001, the camera control unit 8 acquires the focal length information f and the distortion information d stored in the lens side storage unit 14 via the electrical contacts 12 and the lens control unit 13. As described above, the focal length information f is the current focal length information of the imaging optical system 3, and when the lens device 2 is a zoom lens, it varies due to zoom ring operation, etc., so it is updated by communication as needed. The distortion information d is information indicating the projection condition of the imaging optical system 3, and is referred to as such in this specification because it results in image distortion. This distortion information may simply be flag information indicating that the projection condition is that the relative movement amount between the imaging element 6 and the projected image accompanying the movement of the camera side image blur correction unit 7 is different by a predetermined amount or more between the center (near image height 0) and the peripheral area (area with a large image height) (or not). Alternatively, this distortion information may be in the form of a function indicating how the amount of relative movement of the image projected by the imaging element 6 accompanying the movement of the camera-side image blur correction unit 7 changes between the center and the periphery.

[0020] In step S002, the camera control unit 8 first checks whether the focal length information f acquired in step S001 is equal to or smaller than a predetermined focal length f wide If it is determined that the focal length is wider than the focal length f, the process proceeds to step S003. If it is determined that the focal length is wider than the focal length f, the process proceeds to step S007. wide It is preferable that the value be set so that it is possible to determine whether the angle is super wide in this step.

[0021] In step S003, the camera control unit 8 determines whether or not the photographing optical system 3 satisfies a predetermined distortion condition based on the distortion information d acquired in step S001. In this flow, the predetermined distortion condition is the relative movement amount between the projected image and the image sensor in the central part and the peripheral part, which occurs when the image sensor 6 moves by a predetermined amount (d0 and d r) ratio d th (However, th =d r / d0). The distortion information d acquired in step S001 is set to a threshold value d th If it is greater than , it is determined to be true. If it is determined to be true in step S003, the process proceeds to step S004, and if it is determined to be false, the process proceeds to step S007. In other words, if the value corresponding to δ in FIG. 6 exceeds the threshold, the process proceeds to S004, and if it is equal to or less than the threshold, the process proceeds to S007.

[0022] In step S004, the lens side image blur correction control unit 16 starts drive control of the lens side image blur correction unit 15 under the control of the lens control unit 13 notified by the camera control unit 8 that the process has proceeded to this step. If this drive control has already started, the drive control is continued. In step S007, similar to step S004, the lens side image blur correction control unit 16 starts drive control of the lens side image blur correction unit 15. If this drive control has already started, the drive control is continued. In steps S004 and S007, for example, the drive control stroke (upper limit of the correction amount) in step S004 may be set smaller than that in step S007 for subsequent drive.

[0023] After step S004 and step S007, the process proceeds to step S005 and step S008, respectively. In step S005 and step S0008, the camera control unit 8 determines whether or not a shooting start command (called SW2) has been input. More specifically, the camera control unit 8 detects and determines whether or not a release button provided in the imaging system 1000 has been pressed by the photographer. In step S0005, if the camera control unit 8 determines that the release button has been pressed, the process proceeds to step S006. In step S008, if the camera control unit 8 determines that the release button has been pressed, the process proceeds to step S009. In steps S005 and S008, if pressing of the release button is not detected, the process returns to step S001, and the focal length information f and distortion information d are acquired again. This is to accommodate the fact that the focal length information f and distortion information d change when the photographer changes the focal length and the focus state with the zoom lens. In steps S005 and S008, it may be determined whether or not a shooting start instruction has been input other than the photographer pressing the release button. For example, it may be determined whether or not a shooting start instruction has been input from a remote control terminal wirelessly connected to the camera body 1. In addition, in a configuration in which the shooting start instruction is input by the camera body 1 automatically detecting the shooting conditions based on the image information obtained by the image sensor 6, it may be determined whether or not this shooting start instruction has been input.

[0024] In step S006, the camera control unit 8 transmits an instruction to the lens control unit 13 to start the lens side priority control described later, and starts the lens side priority control. This lens side priority control is continuously performed until the exposure time is completed. On the other hand, in step S009, the camera control unit 8 transmits an instruction to the lens control unit 13 to start the cooperative control described later, and starts the cooperative control described later. This cooperative control is also continuously performed until the exposure time is completed. That is, in this flow, based on the focal length information f and the distortion information d, a drive mode in which the image blur correction is performed is selected from the lens side priority control and the cooperative control, and the image blur correction is performed based on the selected mode. Note that the timing of the instruction from the camera control unit 8 to the lens control unit 13 as to which mode, the lens side priority control and the cooperative control, to perform the image blur correction is not particularly important. For example, as soon as it is determined which mode to set in steps S002 and S0003, instruction information may be transmitted based on the selection result. In this embodiment, the lens side image blur correction control unit 16 and the lens side image blur correction unit 15 also perform lens side priority control or cooperative control based on the determination result by the camera control unit 8. In this specification, even when indirect control is performed via the lens control unit 13 in this way, it is expressed that the camera control unit 8 controls the lens side image blur correction control unit 16 and the lens side image blur correction unit 15.

[0025] When the exposure time is completed in steps S006 and S009, the process proceeds to step S010, where the imaging process ends, and the process proceeds to step S011. In step S011, it is determined whether or not the main switch of the imaging system 1000 has been turned off. If it is determined that the main switch has not been turned off, the process returns to step S001 to prepare for the next imaging. If the main switch has been turned off, this flow ends in order to perform a camera shutdown process. Note that this flow may also end when it is determined that the camera body 1 has switched to a playback mode in which the captured image is played back on a display unit (not shown) other than when the main switch has been turned off.

[0026] FIG. 3 is a subroutine flow diagram for explaining the lens-side priority control executed in step S006 of FIG. 2. As described above, the relative movement amount between the subject image and the image sensor accompanying the movement of the image sensor by a predetermined amount is different between the central part with a low image height and the peripheral part with a high image height. Therefore, under conditions where the difference in the relative movement amount between the central part and the peripheral part is large, the lens-side image blur correction that performs image blur correction by moving the correction optical system can reduce the remaining blur in the peripheral part more than the camera-side image blur correction that performs image blur correction by moving the image sensor. Therefore, in this subroutine, the image blur correction using the lens-side image blur correction unit 15 is used in preference to the image blur correction using the camera-side image blur correction unit 7, thereby reducing the remaining blur in the peripheral part even under conditions where the difference in the relative movement amount between the central part and the peripheral part is large. In other words, the fact that this subroutine has been reached means that it has been determined that the conditions correspond to the conditions where the influence of blur can be reduced by performing image blur correction by using the lens-side image blur correction unit 15 in preference to the image blur correction using the camera-side image blur correction unit 7.

[0027] Specifically, in this subroutine, if the amount of shake applied to the imaging system 1000 is an amount that can be corrected without using the camera-side image blur correction unit 7, the camera-side image blur correction unit 7 is not used and the image blur is corrected using the lens-side image blur correction unit 15. On the other hand, if the amount of shake applied to the imaging system 1000 is large and the correction angle is insufficient without using the camera-side image blur correction unit 7, the lens-side image blur correction unit 15 is used to perform image blur correction for the insufficient amount, while the camera-side image blur correction unit 7 is used to perform image blur correction for the insufficient amount. Also, at the start of this subroutine, in response to SW2 detected in step S005 of FIG. 2, the image sensor 6 starts exposure for capturing a recording image. Each step of this subroutine will be described with reference to FIG. 3.

[0028] 3 is executed under the control of the camera side image blur control unit 9 and the lens side image blur correction control unit 16 by the camera control unit 8 and the lens control unit 13. When the lens control unit 13 receives an instruction to start lens side priority control, it sets the image blur correction drive mode so that the lens side image blur correction unit 15 performs image blur correction with lens side priority control, and the subroutine in FIG.

[0029] In step S101, the lens side image blur correction control unit 16 drives and controls only the lens side image blur correction unit 15. The lens side image blur correction control unit 16 calculates a correction amount based on the shake amount applied to the imaging system 1000, and drives and controls the lens side image blur correction unit 15 so that the correction optical system 19 moves based on the calculated correction amount. The shake amount may be acquired based on the output of a sensor that physically measures the momentum, such as an angular velocity sensor, or may be acquired based on an image, or may be acquired based on both. Since a known technique can be used for the calculation method of the correction amount, details are omitted. For example, the shake angle can be acquired by integrating the output from which noise, etc. is cut using a filter from the output of the angular velocity sensor, and the shake angle can be acquired by dividing it by the sensitivity (the amount of change in the optical axis direction per unit movement amount of the correction optical system).

[0030] In step S102, the lens side image blur correction control unit 16 determines whether or not the lens side image blur correction unit 15 has attempted to drive the correction optical system 19 beyond its control range (movable range), that is, whether or not the state has reached a so-called stroke-out state. If it is determined that the state is in the stroke-out state, the process proceeds to step S103, and if it is determined that the state is not in the stroke-out state, the process proceeds to step S107.

[0031] In step S103, the lens side image blur correction control unit 16 stops the lens side image blur correction unit so that it holds the position where the lens side image blur correction unit reaches the stroke-out. At almost the same time, the camera side image blur correction control unit 9 starts driving the camera side image blur correction unit 7, which had been stopped at the reference position (called the center) until then. Such transfer of drive control is performed by using the camera side image blur correction control unit 9 and the lens side image blur correction control unit 16, with the camera control unit 8 and the lens control unit 13 communicating with each other via electrical contacts. More specifically, the position signal of the lens side image blur correction unit 15 and the control state of the lens side image blur correction control unit 16 transmit to the camera control unit 8 via the lens control unit 13 and the electrical contacts 12 that the position of the correction optical system 19 has reached the end of the control range. The camera control unit 8, having received this, instructs the camera side image blur correction control unit 9 to start driving the camera side image blur correction unit 7. The reference position is the position of the camera-side image blur correction unit 7 when the image stabilization function is stopped or when the amount of shake is zero, and generally refers to the position where the optical axis is incident on the light receiving surface of the image sensor 6 near the center of the range used for imaging (called the imaging area). Then, the process proceeds to step S104.

[0032] In step S104, the camera side image blur correction control unit 9 judges whether or not the position of the camera side image blur correction unit 7 being driven has returned to the center. If it is judged that it has returned to the center, the process proceeds to step S105, and if it is judged that it has not returned to the center, the process proceeds to step S106. In step S106, the process judges whether or not a predetermined exposure time has elapsed since the exposure operation that has already been started in response to SW2 was started. If it is judged that it has not elapsed, the process returns to step S104, and if it has elapsed, the subroutine is terminated.

[0033] On the other hand, in step S105, the camera-side image blur correction control unit 9 performs positioning control so that the camera-side image blur correction unit 7 maintains the center position again when it returns to the center, and the process proceeds to step S107. In step S107, as in step S106, it is determined whether a predetermined exposure time has elapsed. If it is determined that the exposure time has not elapsed, the process returns to step S101, and if it is determined that the exposure time has elapsed, the process ends this subroutine as in step S106. According to the flow of this subroutine, the lens-side image blur correction unit 15 performs image blur correction until the lens-side image blur correction unit 15 strokes out. Then, at the point in time when the lens-side image blur correction unit 15 strokes out, the camera-side image blur correction unit 7 takes over the image blur that cannot be corrected by the lens-side image blur correction unit 15, and the image blur correction is driven and controlled. Note that the lens-side priority control is not limited to this. For example, the camera side image blur correction section 7 may be started to be driven just before the lens side image blur correction section 15 strokes out, so that the above-mentioned handover can be executed more smoothly.

[0034] That is, in the lens-side priority control, when the shake amount of the imaging system is equal to or less than a threshold, the lens-side image blur correction unit 15 is controlled to drive (move) based on the shake amount. On the other hand, when the shake amount of the imaging system exceeds a threshold, the lens-side image blur correction unit 15 and the camera-side image blur correction unit 7 are controlled to drive based on the correction amount. When the shake amount exceeds a threshold, the lens-side image blur correction unit 15 is controlled to drive based on the shake amount of the threshold, and the camera-side image blur correction unit 7 is controlled to drive based on the shake amount corresponding to the difference between the shake amount of the imaging system and the threshold. For example, the camera control unit 8 controls the camera-side image blur correction unit 7 via the camera-side image blur control unit 9 so that the camera-side image blur correction unit 7 moves based on the difference between the first correction amount acquired based on the shake amount and the correction amount corresponding to the threshold (stroke in the case of FIG. 3). As a result, the movement amount of the correction optical system 19 is suppressed to be equal to or less than the image blur correction amount corresponding to the threshold (stroke).

[0035] FIG. 4 is a subroutine flow diagram for explaining the cooperative control executed in step S009 in FIG. 2. In this subroutine, even if the amount of shake of the imaging system 1000 is large enough to be corrected only by image shake correction using the lens side image shake correction unit 15, image shake correction is performed using the lens side image shake correction unit 15 and the camera side image shake correction unit 7. In the above-mentioned lens side priority control, after it is determined that the lens side image shake correction unit 15 is stroked out, the lens device 2 notifies the camera body of this fact by communication, and then the driving of the camera side image shake correction unit 7 starts. Therefore, a delay may occur in the driving of the camera side image shake correction unit 7. In addition, the camera body 1 and the lens device 2 need to communicate with each other during the exposure period. In general, communication between the camera body 1 and the lens device 2 takes more time than communication between each block inside the camera body or the lens device, so the accuracy of the image shake correction may be reduced due to the influence of communication delays. Therefore, in this subroutine, a drive ratio, which is the ratio of shake correction shared between the lens side image shake correction unit 15 and the camera side image shake correction unit 7, is determined, and image shake correction is performed at each drive ratio, thereby reducing the effect of delays associated with these communications more than in the subroutine of Fig. 3. In other words, the fact that this subroutine has been reached means that it has been determined that the effect of residual blur in the peripheral area caused by the difference in the amount of relative movement between the center and peripheral areas is small, even if image shake correction is performed using both the lens side image shake correction unit 15 and the camera side image shake correction unit 7. Each step of this subroutine will be explained using Fig. 4.

[0036] 4 is executed under the control of the camera side image shake control unit 9 and the lens side image shake correction control unit 16 by the camera control unit 8 and the lens control unit 13. When the lens control unit 13 receives an instruction to start cooperative control, it sets the image shake correction drive mode so that the lens side image shake correction unit 15 performs image shake correction by cooperative control, and the subroutine in FIG.

[0037] In step S201, the lens-side image blur correction control unit 16 acquires the current position of the lens-side image blur correction unit 15 immediately before SW2 is determined, and proceeds to step S202. In step S202, the camera control unit 8 calculates the correction angles currently held by the camera side and the lens side image blur correction unit, taking into account the remaining stroke amount calculated from the current position of the lens-side image blur correction unit 15 acquired in step S201. The total correction angle held by both image blur correction units can be acquired when the lens device 2 is attached or when the zoom position is fixed, but in this step, it is recalculated based on the stroke available to the lens-side image blur correction unit 15 when SW2 is detected. In addition, in step S202, the camera control unit 8 determines the drive ratio, which is the ratio of the camera side and lens side correction angles that can be realized with the stroke amount held by both correction means. The drive ratio is the sharing ratio of the shake correction as described above.

[0038] In step S203, image blur correction control is started based on the drive ratio acquired in step S202. For example, when the drive ratio is the lens side 4 and the camera side 6, and the imaging system 1000 rotates by θ, a drive ratio of 0.4 is set in the lens side image blur correction control unit 16 so that 0.4×θ is corrected by the lens side image blur correction unit 15. Similarly, a drive ratio of 0.6 is set in the camera side image blur correction control unit 9 so that 0.6×θ is corrected by the camera side image blur correction unit 7. A method for driving and controlling the lens side image blur correction control unit 16 and the camera side image blur correction control unit 9 at a predetermined drive ratio can be a known method, so a detailed description will be omitted. For example, the lens side image blur correction control unit 16 may acquire the shake amount of the imaging system 1000, acquire the lens side image blur correction amount and the camera side image blur correction amount based on the shake amount and the drive ratio, and perform drive control by transmitting the camera side image blur correction amount to the camera body 1 side. Also, if the lens device 2 and the camera body 1 can each obtain the amount of shake, the image blur correction control units (6, 9) may obtain the amount of correction based on the drive ratio obtained in step S202 and the amount of shake obtained by each. In this method, the camera body 1 and the lens device 2 each obtain their own correction amount, so that once the drive ratio is transmitted to the lens device 2, each can perform image blur correction, which is less susceptible to communication delays and is more preferable because it reduces the amount of communication. The drive control started in this step continues until exposure is completed.

[0039] After that, exposure is started in step S204, and is completed in step S205, completing this subroutine. The strokes of both image blur correction units can be utilized to the maximum extent by the cooperative control in this subroutine. At this time, due to the optical characteristics of the lens device 2, image blur correction can be performed without causing a large difference in the image blur correction remaining at the center and peripheral image heights. FIG. 5 is a conceptual diagram for explaining the driving state of both image blur correction units (7, 15) in the lens side priority control and cooperative control described in FIGS. 3 and 4. Here, the driving of the image blur correction unit refers to the driving for the image blur correction unit to move the image sensor 6 or the correction optical system 19, and does not include the driving even if the driving control is necessary to hold each position at a predetermined position. In FIG. 5, the horizontal axis indicates time, and the vertical axis indicates the correction amount of both image blur correction units in angle. The exposure start time is the left end of the graph, and exposure is performed continuously within the time axis of the graph. FIG. 5(a) shows the driving state of the lens side priority control, and FIG. 5(b) shows the driving state of the cooperative control. As shown in FIG. 5(a), in the lens side priority control, at the beginning of the control at the left end of the graph (i.e., immediately after the start of exposure), only the lens side image blur correction unit 15 drives (corresponding to step S101 in FIG. 3). At time T1, it is detected that the lens side image blur correction unit 15 shown as the driving range has reached the control end (i.e., stroke out) (corresponding to step S102 in FIG. 3). Then, from time T1, the lens side image blur correction unit 15 stops at the control end, and the camera side image blur correction unit 7 starts driving (corresponding to step S103 in FIG. 3). When the camera side image blur correction unit 7 returns to the center at time T2, the camera side image blur correction unit 7 is held in place (corresponding to steps S104 and S105 in FIG. 3). Then, at time T2, driving is handed over to the lens side image blur correction unit 15 (corresponding to the second time of step S101 in FIG. 3), and driving of only the lens side image blur correction unit 15 continues until the control end is reached at time T3. From time T3 to T4, the lens side image blur correction unit 15 stops at the control end, as in the case of time T1 to T2, and only the camera side image blur correction unit 7 is driven and controlled. In this way, in the lens side priority control, the lens side image blur correction unit 15 and the camera side image blur correction unit 7 are driven alternately.In this way, by using the lens side image blur correction unit preferentially, the difference in the amount of correction remaining between the central portion and the peripheral portion is reduced, and the amount of blurring in the entire image is reduced.

[0040] In Fig. 5(b), cooperative control is performed based on the drive ratio calculated in step S202 in Fig. 4. That is, during the exposure period shown in the graph, both image blur correction units are driven and controlled with waveforms similar to each other at a predetermined ratio. By switching between the lens side priority control and cooperative control described in Figs. 2 to 5 according to the focal length information f and the distortion information d, it is possible to realize an appropriate image blur correction operation for the photographing optical system 3 of the lens device 2.

[0041] [Variations] In the above-mentioned imaging system 1000, in the "cooperative control", in step S202, the drive ratio of both image blur correction units is determined in consideration of the position of the lens side image blur correction unit 15 immediately before SW2 detection, but the present invention is not limited to this. For example, the ratio may be determined in advance only based on the focal length information when the lens device 2 is attached, and the ratio may be updated when the focal length is changed. However, even if the remaining correction angle of the lens side image blur correction unit 15 at the start of exposure is small (close to the control end), the drive ratio is not determined taking this into consideration, so there is a possibility that the stroke of the lens side image blur correction unit 15 will be insufficient during exposure. Therefore, it is preferable to determine the ratio based on the position of the lens side image blur correction unit 15 immediately before SW2 detection.

[0042] In the above embodiment, the focal length information f is a predetermined focal length f wide The distortion of the photographing optical system is within a predetermined distortion condition d based on the distortion information d. th The "lens side priority control" was performed when both conditions were met. However, the present invention is not limited to this, and the effect can be obtained even if the "lens side priority control" is performed under only one of the conditions. For example, in a general optical system, the focal length f is set to a value such that the difference in the relative movement amount between the center and the periphery (δ in FIG. 6) is equal to or greater than a predetermined value. widemay be set, and the decision based on the distortion information (step S203 in FIG. 2) may be omitted.

[0043] In the above embodiment, the lens side storage unit 14 holds focal length information and distortion information, but focal length information and distortion information may also be taken into account and held as flag information as described above at the design stage. Alternatively, product ID information may be used as at least one of the focal length information and distortion information. For example, when product ID information is used as distortion information, the camera side storage unit may hold a table of product IDs and distortion information, and the camera control unit 8 may acquire distortion information based on the product ID acquired from the lens device and the table. In addition, when the focal length of the lens device 2 is f wide If the focal length of the lens device 2 cannot be shorter than f, the camera control unit 8 can select cooperative control by referring to the table if the storage unit of the camera holds a table of product IDs and focal lengths (movable ranges in the case of zoom lenses). wide Even if the number of the lens-side priority control signals is not more than the number of the product ID signals, the camera control unit 8 can select the lens-side priority control signal based on the product ID.

[0044] In the above-described embodiment, the camera control unit 8 receives an instruction to start shooting and generates and transmits instruction information to start lens side priority control or cooperative control to the lens control unit 13. However, the camera control unit 8 may generate setting instruction information for the drive mode between the time of determining which drive mode to use and the time of inputting an instruction to start shooting and transmit the setting instruction information to the lens control unit 13. In this case, the lens control unit 13 sets the drive mode upon receiving the setting instruction information, and further receives instruction information to start shooting from the camera control unit 8 and starts driving in the set drive mode.

[0045] In the above-described embodiment, the lens side memory unit 14 is arranged within the lens device 2 for convenience, but this is not limited to this, and the lens side memory unit may exist within the camera body or as an external memory unit capable of communicating with the imaging system 1000 without departing from the gist of the present invention.

[0046] In the above-mentioned embodiment, the camera side image blur correction unit 7 and the lens side image blur correction unit 15 move the image sensor 6 and the correction optical system 19 in a plane perpendicular to the optical axis, respectively, but as long as the positions in the perpendicular plane can be moved, they may also be moved in the optical axis direction. In other words, if the optical axis direction is the z-axis direction, it is sufficient that the x and y coordinates of the image sensor 6 and the correction optical system 19 can be changed. In addition, the lens side image blur correction unit 15 changes the position of the optical axis incident on the light receiving surface of the image sensor by moving the position of the correction optical system 19, but lens side image blur correction may be performed using other optical elements.

[0047] In the above embodiment, an example has been described in which the camera control unit 8 controls image shake correction for the entire imaging system 1000 through communication with the lens control unit 13. However, the lens control unit 13 may control image shake correction for the entire imaging system 1000, or another device connectable to at least one of the camera control unit 8 and the lens control unit 13 may control it. Also, image shake correction for the entire imaging system 1000 may be controlled by another device performing part or all of the processing performed by the camera control unit 8 and the lens control unit 13.

[0048] In "lens side priority control", the lens side image blur correction unit 15 is driven and controlled preferentially in order to reduce the difference in the amount of remaining blur between the center and periphery from the viewpoint of image blur correction. In fact, in such an optical system, the amount of distortion over the entire screen is generally large. In this case, after the above-mentioned image blur correction is performed, distortion correction may be performed as image processing before recording as an image. Image processing may be in a format in which only the image processing method is recorded and post-processing is possible.

[0049] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0050] Although the 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 the gist of the present invention. [Explanation of symbols]

[0051] 1 Camera body 2 Lens device 3. Shooting optical system 6. Image sensor 7 Camera side image stabilization unit 8 Camera control section 9 Camera side image stabilization control section 13 Lens control unit 14 Lens side memory unit 15 Lens side image stabilization unit 16 Lens side image stabilization control unit

Claims

1. a first image blur correction unit that changes the direction of an optical axis of the photographing optical system by moving an optical element included in the photographing optical system; a control device for controlling driving of an image pickup element that captures a subject image formed by light transmitted through the photographing optical system and a second image blur correction means that moves in a plane perpendicular to the optical axis, a selection means for acquiring information indicating a focal length of the photographing optical system, and selecting a drive mode of image blur correction using the first image blur correction means and the second image blur correction means based on the information indicating the focal length; a drive control unit that drives the first image blur correction unit and the second image blur correction unit in a drive mode selected by the selection unit, the selection means selects a first drive mode when the focal length is a first value smaller than a predetermined value, and selects a second drive mode different from the first drive mode when the focal length is a second value not smaller than the predetermined value; The drive control means includes: When the first driving mode is selected, When an amount of shake of an imaging device including the imaging element is equal to or smaller than a first threshold value, the first image blur correction means is driven and controlled so as to be driven based on the amount of shake, and when the amount of shake is greater than the first threshold value, the first image blur correction means and the second image blur correction means are driven and controlled so as to be driven based on the amount of shake; When the second driving mode is selected, a control device which controls the first image blur correction means and the second image blur correction means to be driven based on the amount of shake and a predetermined drive ratio determined before exposure starts.

2. The drive control means includes: When the first driving mode is set, 2. The control device according to claim 1, further comprising: a control unit for controlling the driving of the first image blur correction means so that the amount of movement of the optical element is equal to or smaller than an amount of image blur correction corresponding to the first threshold value.

3. The image blur correction amount corresponding to the first threshold value is 3. The control device according to claim 2, wherein the distance is a distance from a reference position of the optical element to an end of the optical element controlled by the first image blur correction means.

4. The drive control means includes: When the first driving mode is set and the shake amount is greater than the first threshold value, 4. The control device according to claim 1, further comprising: a control unit for controlling the second image blur correction means to be driven based on a shake correction amount corresponding to a difference between the shake amount and the first threshold value.

5. The selection means is 5. The control device according to claim 1, wherein the drive mode is selected based on the focal length and distortion information of the photographing optical system.

6. The selection means is determining whether or not a difference in a relative movement amount between the image sensor and a subject image at a central portion and a peripheral portion of an imaging area of ​​the image sensor is equal to or smaller than a second threshold value when the image sensor moves by a predetermined amount based on distortion information of the photographing optical system; selecting a first driving mode when the focal length is the first value and the difference in the amount of relative movement exceeds the second threshold value; 5. The control device according to claim 4, wherein the second driving mode is selected when the focal length is the second value and when the focal length is the first value and the difference in the amount of relative movement is equal to or less than the second threshold value.

7. 7. The control device according to claim 1, further comprising a setting unit that sets the drive ratio based on a position of the optical element at a timing when a shooting start instruction is received.

8. 8. The control device according to claim 1, further comprising a setting unit that sets the drive ratio based on a focal length of the photographing optical system at a timing when a photographing start instruction is received.

9. 9. An imaging apparatus comprising: the control device according to claim 1; the imaging element; and the second image blur correction means.

10. A lens device including the photographing optical system can be attached to the lens device.

10. The imaging device according to claim 9, wherein the first threshold value is changed depending on the lens device attached.

11. 9. A lens device comprising: the control device according to claim 1; the photographing optical system; and the first image blur correction means.

Images