Control apparatus, image capturing apparatus, control method, and storage medium

Abstract

To provide a controller capable of highly accurately correcting minute and high-speed blurring during exposure.SOLUTION: The control device (9) includes an acquirer (9a) configured to acquire information relating to an exposure period, and a controller (9b) configured to control the first blur corrector (13) and the second blur corrector (7) in the exposure period based on the information, the exposure period includes a first period and a second period, the first shake correction means has a smaller stroke and higher responsiveness than the second shake correction means, and the control means drives the first shake correction means in the first period and drives the second shake correction means and does not drive the first shake correction means in the second period.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a control device, an imaging device, a control method, and a program. [Background technology]

[0002] When an image is taken using an imaging device, there is a certain period during a single exposure period during which minute, high-speed image blur is noticeable. Patent Document 1 discloses an imaging device that controls an image blur correction means by adding correction data to correct for shocks caused by shutter travel and charging vibrations during shooting. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-113836 Summary of the Invention [Problem to be solved by the invention]

[0004] However, while the imaging device disclosed in Patent Document 1 can reduce the effects of vibrations caused by shutter travel and charging during shooting, it does not take into consideration image blur correction that responds to other changes in conditions during exposure.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a control device that can perform image blur correction in accordance with changes in the situation during exposure. [Means for solving the problem]

[0006] A control device according to one aspect of the present invention includes an acquisition means for acquiring information relating to an exposure period, and a control means for controlling a first blur correction means and a second blur correction means during the exposure period based on the information, wherein the exposure period includes a first period and a second period, the first blur correction means has a smaller stroke and higher responsiveness than the second blur correction means, and the control means drives the first blur correction means during the first period, and drives the second blur correction means but does not drive the first blur correction means during the second period.

[0007] Other objects and features of the present invention are illustrated in the following examples. [Effects of the Invention]

[0008] According to the present invention, it is possible to perform image blur correction in accordance with changes in the situation during exposure. [Brief explanation of the drawings]

[0009] [Figure 1] 1A and 1B are a schematic cross-sectional view and a schematic block diagram of an imaging system in each embodiment. [Figure 2] 5A to 5C are explanatory diagrams of the passage of time and the operation of the image blur correction means when photographing is performed using rear curtain synchronization in the first embodiment. [Figure 3] 10A and 10B are explanatory diagrams of the passage of time and the operation of the image blur correction means when photographing is performed using front curtain synchronization in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Example]

[0011] First, with reference to FIGS. 1(a) and 1(b), the configuration and operation of an imaging system 1000 according to a first embodiment of the present invention will be described. FIG. 1(a) is a schematic cross-sectional view of the imaging system 1000. FIG. 1(b) is a schematic block diagram of the imaging system 1000. The imaging system 1000 is a so-called interchangeable lens single-lens camera system that includes a camera body (imaging device) 1 and an interchangeable lens (lens apparatus) 2 that is detachable from the camera body 1. The camera body 1 and the interchangeable lens 2 can be connected via a camera mount, and function as the imaging system 1000. However, this embodiment is not limited to this, and can also be applied to an imaging device in which the camera body and the lens apparatus are integrally configured.

[0012] The interchangeable lens 2 has an imaging optical system 3. A light beam coming from a subject passes through the imaging optical system 3 and is imaged on the imaging element 5 of the camera body 1. The imaging element 5 photoelectrically converts the light beam (optical image) into an image signal. The image signal is guided to an image processing unit 10. The image processing unit 10 performs various development processes on the image signal. A memory unit 11 stores the image processed by the image processing unit 10 as an image file.

[0013] In order to prevent the captured image from being degraded (to reduce image blur) due to vibrations such as camera shake applied to the imaging system 1000, the interchangeable lens 2 has an image blur correction means (first image blur correction means) 13, and the camera body 1 has an image blur correction means (second image blur correction means) 7.

[0014] The camera body 1 has a control unit (control device) 9 that controls each unit of the imaging system 1000. The control unit 9 has an acquisition unit 9a and a control unit (image stabilization control unit) 9b. The acquisition unit 9a acquires information about the exposure period (the period from when the shutter begins to open to when it finishes closing). The control unit 9b controls the image stabilization unit 13 and the image stabilization unit 7 during the exposure period based on the information about the exposure period. The control unit 9b controls each of the image stabilization units 7 and 13 to move in a plane perpendicular to the optical axis 4, thereby reducing (cancelling) image blur caused by vibrations such as camera shake. The imaging system 1000 has a light emitting unit (illumination device) 14. The light emitting unit 14 emits light when capturing an image based on instructions from the control unit 9.

[0015] Because image blur correction means 13 uses a piezoelectric element as a driving means, it has a relatively small stroke and is highly responsive. This allows image blur correction means 13 to respond to faster image blur. On the other hand, image blur correction means 7 uses a voice coil motor as a driving means, so it has a relatively large stroke and is less responsive than image blur correction means 13. This allows image blur correction means 7 to respond to larger image blur.

[0016] As described above, in this embodiment, the image blur correction means 13 serving as the first blur correction means has a smaller stroke and higher responsiveness than the image blur correction means 7 serving as the second blur correction means. However, this embodiment is not limited to this, and the image blur correction means 7 may serve as the first blur correction means, and the image blur correction means 13 may serve as the second blur correction means. Alternatively, the image blur correction means 7 may be configured to include both the first blur correction means and the second blur correction means. Similarly, the image blur correction means 13 may be configured to include both the first blur correction means and the second blur correction means.

[0017] When capturing a still image, the start and end of exposure can be determined by the movement of the mechanical front and rear curtains of the shutter device (focal plane shutter device) 6 on the subject side of the image sensor 5. The mode in which exposure is performed using the mechanical front and rear curtains is called the mechanical front curtain drive mode. The shutter control means 8 controls the drive of the mechanical front and rear curtains of the shutter device 6 based on commands from the control unit 9. However, in this embodiment, the mode in which exposure is performed is not limited to this, and other modes such as an electronic shutter mode may also be used.

[0018] Next, a case where photography is performed using light-emitting means 14 will be described with reference to Fig. 2. Fig. 2 is an explanatory diagram showing the passage of time and the operation of image blur correction means 13 and image blur correction means 7 when photography is performed using rear-curtain synchronization, which emits light just before the mechanical rear curtain of shutter device 6 begins to close and can irradiate the subject with strobe light after capturing a light trail or the like.

[0019] In FIG. 2, the horizontal axis represents time. The gray bands (waveforms W1 and W2) represent the drive status of the image stabilization unit 13 and the image stabilization unit 7 during the exposure period and the light emission period (predetermined period, first period), respectively. t1 represents the start time of the exposure period (second period), t2 represents the start time of the predetermined period (first period) (end time of the second period), and t3 represents the end time of the exposure period and the predetermined period (first period). Waveform W1 represents high-speed drive of the image stabilization unit 13 with a small stroke. Waveform W2 represents drive of the image stabilization unit 7 with a large stroke, which is relatively slower than drive of the image stabilization unit 13. Note that waveforms W1 and W2 shown in FIG. 2 are examples used to explain the characteristics of drive of the image stabilization unit 7 and the image stabilization unit 13, and other waveform shapes may be used as long as the drive stroke and speed satisfy the above relationship.

[0020] At time t1, when exposure begins, control means 9a controls image blur correction means 7 to operate. At the same time that light emission by light emitting means 14 begins, image blur correction means 13 is also controlled to operate. The predetermined period during which image blur correction means 13 operates begins at time t2 (after the end of the second period), and this predetermined period is determined in advance (before exposure begins or during preparation for shooting). At time t3, when light emission ends, the exposure period ends, and image blur correction means 7 and image blur correction means 13 are controlled to stop.

[0021] In this embodiment, the image stabilization means 7 is controlled to move during the light emission period (predetermined period) of the light emitting means 14. However, this embodiment is not limited to this, and the image stabilization means 7 may be controlled not to move during the light emission period (predetermined period).

[0022] According to this embodiment, the image stabilization means 13 is driven during the period when the light emitting means 14 emits light for rear curtain synchronization, making it possible to appropriately deal with high-frequency image blur that can become noticeable during short periods of light emission. Furthermore, during the period when the image stabilization means 13 is driven, it is possible to appropriately deal with low-frequency image blur and large-amplitude image blur that the image stabilization means 13 cannot deal with. Furthermore, by driving the image stabilization means 13 only during a portion of the exposure period, it is possible to reduce power consumption and noise caused by driving the image stabilization means 13. [Example]

[0023] Next, a second embodiment of the present invention will be described with reference to Fig. 3. The basic configuration of the imaging system of this embodiment is the same as that of the imaging system 1000 described in the first embodiment with reference to Fig. 1, and therefore a description thereof will be omitted.

[0024] FIG. 3 is an explanatory diagram showing the passage of time and the operation of image blur correction means 13 and image blur correction means 7 when photographing is performed using front-curtain synchronization, in which light is emitted at the same time as the front-curtain shutter of shutter device 6 travels and the shutter is fully opened.

[0025] In FIG. 3, the horizontal axis represents time. The gray bands (waveforms W3 and W4) indicate the drive status of the image stabilization unit 13 and the image stabilization unit 7 during the exposure period and the light emission period (predetermined period, first period), respectively. t4 indicates the start time of the exposure period and the predetermined period (first period), t5 indicates the end time of the predetermined period (first period) (start time of the second period), and t6 indicates the end time of the exposure period (end time of the second period). Waveform W3 indicates high-speed drive of the image stabilization unit 13 with a small stroke. Waveform W4 indicates drive of the image stabilization unit 7 with a large stroke, which is relatively slower than drive of the image stabilization unit 13. Note that waveforms W3 and W4 shown in FIG. 2 are examples used to explain the characteristics of drive of the image stabilization unit 7 and the image stabilization unit 13, and other waveform shapes may be used as long as the drive stroke and speed satisfy the above relationship.

[0026] At time t4, when the shutter is fully opened, light emission by the light-emitting means 14 begins, and at the same time, the control means 9b controls the image stabilization means 13 and the image stabilization means 7 to move. After the light emission period ends at time t5, only the image stabilization means 7 is controlled to move. However, this embodiment is not limited to this, and the image stabilization means 13 may also be controlled to move after time t5 within a range where the predetermined period is not longer than the exposure period. Note that in this embodiment, the image stabilization means 7 is controlled to move during the light emission period (predetermined period) by the light-emitting means 14, but this is not limited to this. The image stabilization means 7 may also be controlled not to move during the light emission period.

[0027] According to this embodiment, the image stabilization means 13 is driven during the period when the light emitting means 14 emits light for front curtain synchronization, making it possible to appropriately deal with high-frequency image blur that can become noticeable during short periods of light emission. Furthermore, during the period when the image stabilization means 13 is driven, it is possible to appropriately deal with low-frequency image blur and large-amplitude image blur that the image stabilization means 13 cannot deal with. Furthermore, by driving the image stabilization means 13 only during a portion of the exposure period, it is possible to reduce power consumption and noise caused by driving the image stabilization means 13.

[0028] As described above, in each embodiment, the control unit 9b drives the first motion compensation unit during the first period, and drives the second motion compensation unit but does not drive the first motion compensation unit during the second period. Preferably, the control unit 9b drives the second motion compensation unit together with the first motion compensation unit during the first period.

[0029] Preferably, the first period varies depending on the light-emitting period of the light-emitting means 14. More preferably, the first period corresponds to the light-emitting period and starts after the second period ends, and the control means 9b drives the second blur correction means but does not drive the first blur correction means during the second period, and drives at least the first blur correction means during the first period (rear curtain synchronization). Alternatively, preferably, the first period corresponds to the light-emitting period and ends before the start of the second period, and the control means 9b drives at least the first blur correction means during the first period, and drives at least the second blur correction means during the second period (front curtain synchronization).

[0030] In each embodiment, the predetermined period corresponds to the light-emitting period (the light-emitting period and the predetermined period are approximately the same), but is not limited to this. A part of the light-emitting period may be set as the predetermined period within any range that can reduce high-frequency blurring that becomes noticeable within the light-emitting period. In each embodiment, the predetermined period may be set as a part of the exposure period, including a period different from the light-emitting period.

[0031] In each embodiment, the control unit 9b may change the control of the drive of at least one of the first image blur correction unit and the second image blur correction unit depending on whether or not the light emitting unit 14 is caused to emit light during the exposure period. This allows for more appropriate image blur correction depending on whether or not the light emitting unit 14 is operated.

[0032] In each embodiment, the control unit 9b may change the control of driving at least one of the first motion compensation unit and the second motion compensation unit according to the light emission period of the light emission unit 14. For example, the control unit 9b drives the first motion compensation unit when the light emission period is longer than a predetermined light emission period, and does not drive the first motion compensation unit when the light emission period is shorter than the predetermined light emission period. By not operating the first motion compensation unit when the light emission period is short, it is possible to reduce power consumption.

[0033] In each embodiment, the control unit 9b may change the control of driving at least one of the first shake correction unit and the second shake correction unit depending on the exposure period. For example, when the exposure period is longer than a predetermined exposure period, the control unit 9b drives the first shake correction unit during the first period, drives the second shake correction unit during the second period, and does not drive the first shake correction unit. For example, when the exposure period is shorter than the predetermined exposure period, the control unit 9b drives the second shake correction unit during the first period, and does not drive the first shake correction unit. When the exposure period is short, not operating the first shake correction unit can reduce power consumption.

[0034] In each embodiment, the control unit 9b may change, in accordance with a user setting, the control of driving at least one of the first image blur correction unit and the second image blur correction unit when emitting light from the light emitting unit 14. This allows for more appropriate image blur correction to be performed in accordance with the user's preferences.

[0035] Furthermore, while each embodiment describes an example in which the first image stabilization unit is driven to appropriately address high-frequency image blur during the light emission period, the present invention can also be applied to cases in which it is necessary to appropriately address high-frequency image blur only during a portion of the exposure period. For example, when a super-resolution image is generated by combining images obtained by shifting the position of the image sensor 5 by a predetermined amount using the second image stabilization unit, image blur during the micro-vibration period from when the image sensor 5 is shifted by the predetermined amount until the image sensor 5 stops can be addressed. In this case, image blur during the micro-vibration period until the image sensor 5 stops can be reduced by driving the first image stabilization unit. Therefore, exposure can be started during the micro-vibration period of the image sensor 5, allowing multiple images to be taken at short intervals. The micro-vibration period from when the image sensor 5 is shifted by the predetermined amount until the image sensor 5 stops and the vibration waveform can be determined in advance through experiments or other means, and information on the length of the period for driving the first image stabilization unit and the drive waveform can be stored in the memory of the control unit 9. Alternatively, the user may be able to select the period during the exposure period during which the first image stabilization unit is driven. For example, a bar corresponding to the length of the exposure period may be displayed on a display unit provided on camera body 1, and the user may select the timing to start and stop driving the first image blur correction means by touching the display unit. The method by which the user selects the period for driving the first image blur correction means may be other methods, such as by the user operating an operation unit of an external device other than camera body 1. (Other Examples) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0036] According to each embodiment, it is possible to provide a control device, an imaging device, a control method, and a program that perform image blur correction in response to changes in the situation during exposure.

[0037] The disclosure of each embodiment includes the following configurations and methods. (Configuration 1) an acquisition means for acquiring information regarding an exposure period; a control unit that controls the first image blur correction unit and the second image blur correction unit during the exposure period based on the information; the exposure period includes a first period and a second period, the first vibration reduction means has a smaller stroke and higher responsiveness than the second vibration reduction means; The control means driving the first image stabilization means during the first period; A control device, characterized in that, during the second period, the second motion compensation means is driven and the first motion compensation means is not driven. (Configuration 2) 2. The control device according to configuration 1, wherein the control means drives the first motion compensation means and the second motion compensation means during the first period. (Configuration 3) 3. The control device according to configuration 1 or 2, wherein the exposure period is a period from when the shutter starts to open to when it finishes closing. (Configuration 4) 4. The control device according to any one of configurations 1 to 3, wherein the first period is determined before exposure starts. (Configuration 5) 5. The control device according to any one of configurations 1 to 4, wherein the first period varies depending on the light emitting period of the light emitting means. (Configuration 6) the first period corresponds to the light-emitting period and starts after the second period ends; The control means during the second period, the second motion compensation means is driven and the first motion compensation means is not driven; 6. The control device according to configuration 5, wherein at least the first image stabilization means is driven during the first period. (Configuration 7) the first period corresponds to the light-emitting period and ends before the second period begins; The control means During the first period, at least the first image stabilization means is driven; The control device according to configuration 5, wherein at least the second image stabilization means is driven during the second period. (Configuration 8) The control device according to any one of configurations 1 to 7, wherein the control means changes control of driving of at least one of the first image stabilization means and the second image stabilization means depending on whether or not the light emitting means is caused to emit light during the exposure period. (Configuration 9) 9. The control device according to any one of configurations 1 to 8, wherein the control means changes the control of driving at least one of the first image stabilization means and the second image stabilization means in accordance with a light emitting period of the light emitting means. (Configuration 10) The control means If the light emission period is longer than a predetermined light emission period, driving the first image blur correction means; 10. The control device according to configuration 9, wherein the first blur correction means is not driven when the light emission period is shorter than the predetermined light emission period. (Configuration 11) 11. The control device according to any one of configurations 1 to 10, wherein the control means changes the control of driving at least one of the first image stabilization means and the second image stabilization means in accordance with the exposure period. (Configuration 12) When the exposure period is longer than a predetermined exposure period, the control means driving the first image stabilization means during the first period; 12. The control device according to configuration 11, wherein, during the second period, the second motion compensation means is driven and the first motion compensation means is not driven. (Configuration 13) 13. The control device according to configuration 12, wherein the control means drives the second image blur correction means and does not drive the first image blur correction means during the first period when the exposure period is shorter than the predetermined exposure period. (Configuration 14) The control device according to any one of configurations 1 to 13, wherein the control means changes the control of driving at least one of the first image stabilization means or the second image stabilization means when causing the light emitting means to emit light, in accordance with a user setting. (Configuration 15) 15. The control device according to any one of the first to fourth aspects, wherein the first period is selectable by a user. (Configuration 16) 16. An imaging device comprising the control device according to any one of configurations 1 to 15 and an imaging element. (Method 1) an acquisition step of acquiring information regarding an exposure period; a control step of controlling the first image blur correction means and the second image blur correction means during the exposure period based on the information, the exposure period includes a first period and a second period, the first vibration reduction means has a smaller stroke and higher responsiveness than the second vibration reduction means; In the control step, driving the first image stabilization means during the first period; A control method comprising: driving the second motion compensation means and not driving the first motion compensation means during the second period. (Configuration 17) A program that causes a computer to execute the control method described in Method 1.

[0038] 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 invention. [Explanation of symbols]

[0039] 7. Image blur correction means (second image blur correction means) 9 Control unit (control device) 9a Acquisition method 9b Control means 13 Image blur correction means (first image blur correction means)

Claims

1. an acquisition means for acquiring information regarding an exposure period; a control unit that controls the first image blur correction unit and the second image blur correction unit during the exposure period based on the information, the exposure period includes a first period and a second period, the first vibration reduction means has a smaller stroke and higher responsiveness than the second vibration reduction means; The control means driving the first image stabilization means during the first period; A control device, characterized in that, during the second period, the second motion compensation means is driven and the first motion compensation means is not driven.

2. 2. The control device according to claim 1, wherein the control means drives the first motion compensation means and the second motion compensation means during the first period.

3. 2. The control device according to claim 1, wherein the exposure period is a period from when the shutter starts to open to when it finishes closing.

4. 2. The control device according to claim 1, wherein the first period is determined before the start of exposure.

5. 5. The control device according to claim 1, wherein the first period varies depending on a light emitting period of a light emitting means.

6. the first period corresponds to the light-emitting period and starts after the second period ends; The control means during the second period, the second motion compensation unit is driven and the first motion compensation unit is not driven; 6. The control device according to claim 5, wherein at least the first motion compensation means is driven during the first period.

7. the first period corresponds to the light-emitting period and ends before the second period begins; The control means During the first period, at least the first image stabilization unit is driven; 6. The control device according to claim 5, wherein at least the second image stabilization means is driven during the second period.

8. 5. The control device according to claim 1, wherein the control unit changes control of driving of at least one of the first image stabilization unit and the second image stabilization unit depending on whether or not the light emitting unit is caused to emit light during the exposure period.

9. 5. The control device according to claim 1, wherein the control means changes the control of driving at least one of the first image stabilization means and the second image stabilization means in accordance with a light emission period of a light emitting means.

10. The control means If the light emission period is longer than a predetermined light emission period, driving the first image stabilization means; 10. The control device according to claim 9, wherein the first image stabilization means is not driven when the light emission period is shorter than the predetermined light emission period.

11. 5. The control device according to claim 1, wherein the control unit changes the control of driving at least one of the first motion compensation unit and the second motion compensation unit in accordance with the exposure period.

12. When the exposure period is longer than a predetermined exposure period, the control means driving the first image stabilization means during the first period; 12. The control device according to claim 11, wherein, during the second period, the second motion compensation unit is driven and the first motion compensation unit is not driven.

13. 13. The control device according to claim 12, wherein the control means drives the second image blur correction means and does not drive the first image blur correction means during the first period when the exposure period is shorter than the predetermined exposure period.

14. 5. The control device according to claim 1, wherein the control unit changes the control of driving at least one of the first image stabilization unit and the second image stabilization unit when causing the light emitting unit to emit light, in accordance with a setting by a user.

15. 5. The control device of claim 1, wherein the first period is user selectable.

16. An imaging device comprising: the control device according to claim 1; and an imaging element.

17. an acquisition step of acquiring information regarding an exposure period; a control step of controlling the first image blur correction means and the second image blur correction means during the exposure period based on the information, the exposure period includes a first period and a second period, the first vibration reduction means has a smaller stroke and higher responsiveness than the second vibration reduction means; In the control step, driving the first image stabilization means during the first period; a control method for controlling the second image stabilization unit and not driving the first image stabilization unit during the second period;

18. A program causing a computer to execute the control method according to claim 17.

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