Image blur correction control device, imaging device, interchangeable lens, and image blur correction control method

Abstract

To reduce the influence of a shake when cooperatively controlling a plurality of correction means.SOLUTION: An image shake correction control device controls image shake correction performed by first image shake correction means and second image shake correction means having lower image shake correction performance than the first image shake correction means. The image shake correction control device comprises: first acquisition means that acquires a first division ratio; division ratio determination means that determines a final division ratio based on the first division ratio; and control means that controls the first image shake correction means and the second image shake correction means based on the final division ratio determined by the division ratio determination means. The division ratio determination means can determine, as the final division ratio, a division ratio having an increased ratio of the first image shake correction means compared with the first ratio.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an image stabilization control device, an imaging device, an interchangeable lens, and an image stabilization control method. [Background technology]

[0002] Technologies for correcting image blur caused by shake applied to an imaging device are becoming widespread. One method for correcting image blur is optical image blur correction, which corrects image blur by driving a correction optical system, which is part of the optical system, in a plane perpendicular to the optical axis in response to detected shake. Another method is image sensor shift image blur correction, which corrects image blur by driving the image sensor in a plane perpendicular to the optical axis in response to detected shake.

[0003] In recent years, a new technology has emerged that enables the coordinated operation of multiple correction means to expand the range of image blur correction possible, making it possible to correct even large amounts of camera shake that could not be corrected by a single correction means alone.

[0004] Patent Document 1 discloses a technique for dividing an image stabilization signal into a high-frequency band and a low-frequency band, correcting high-frequency image blur with one correction member, and correcting low-frequency image blur with the other correction member. Patent Document 2 discloses a technique for operating a vibration-isolating member with good performance when there are multiple vibration-isolating members, and moving the other members when approaching the stroke end. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 7-104338 [Patent Document 2] Japanese Patent Application Publication No. 2019-129373 Summary of the Invention [Problem to be solved by the invention]

[0006] However, Patent Document 1 does not disclose what criteria are used to determine the division ratio (frequency that serves as the division reference).

[0007] Furthermore, to realize the method of Patent Document 2, it is necessary to properly detect approaching the stroke end and transfer control at high speed, which increases the burden of monitoring and communication for detection.

[0008] The present invention has been made in view of the above circumstances, and has as its object to provide an apparatus that can reduce the effects of blur by performing image blur correction by appropriately coordinating a plurality of correction means with a simple configuration. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, an image blur correction control device according to one aspect of the present invention includes a first image blur correction means and a second image blur correction means. Also statue Poor image stabilization performance The amount of remaining blur after image stabilization is large. and a second image blur correction means for correcting an image blur, the first image blur correction means being a first image blur correction means, and a control means for controlling the first image blur correction means and the second image blur correction means based on the final division ratio determined by the division ratio determination means, the first image blur correction means being a first image blur correction means, and the second image blur correction means being a second image blur correction means. [Effects of the Invention]

[0010] According to the present invention, when a plurality of correction means are controlled in a coordinated manner, it is possible to reduce the influence of blurring.

[0011] Other features and advantages of the present invention will become more apparent from the accompanying drawings and the following detailed description of the preferred embodiment of the present invention. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a block diagram showing the configuration of an imaging apparatus 100 including an image stabilization device. [Figure 2] FIG. 2 is a block diagram illustrating image blur correction control according to the first embodiment. [Figure 3] FIG. 2 is a block diagram illustrating the details of an image blur correction amount calculation unit 203. [Figure 4] FIG. 2 is a block diagram showing an example of the configuration of a division control unit. [Figure 5] FIG. 10 is a diagram illustrating an example of setting a division control means. [Figure 6] FIG. 10 is a diagram illustrating the relationship between the setting of the division control means and the amount of vibration and image blur acting on the imaging device. [Figure 7] FIG. 10 is a block diagram illustrating image blur correction control according to a second embodiment. [Figure 8] FIG. 10 is a block diagram showing an example of the configuration of a division control means according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Elements assigned the same reference numerals throughout the accompanying drawings represent the same or similar elements. The technical scope of the present invention is determined by the claims and is not limited by the individual embodiments below. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the present invention. Furthermore, features described in separate embodiments can also be combined as appropriate.

[0014] In the following embodiments, vibrations applied to an imaging device are referred to as "shake," and the effect on a captured image caused by the shake applied to the imaging device is referred to as "image blur."

[0015] [First embodiment] 1 is a block diagram showing the configuration of an image capture device 100 including an image stabilization device. Image capture device 100 is a digital camera with an interchangeable lens that can capture still images and moving images. However, this embodiment is not limited to digital cameras with an interchangeable lens, and can be applied to various types of image capture devices.

[0016] The imaging device 100 is a system composed of an interchangeable lens 100a and a camera body 100b. The interchangeable lens 100a is configured to be attachable to the camera body 100b, and is used by attaching the interchangeable lens 100a to the camera body 100b. The zoom unit 101 of the interchangeable lens 100a includes a zoom lens that changes magnification. The zoom drive controller 102 drives and controls the zoom unit 101. The aperture unit 103 has an aperture function. The aperture drive controller 104 drives and controls the aperture unit 103. The lens-type image stabilization unit 105 includes an image stabilization lens (hereinafter also referred to as a "correction lens" or "OIS") such as a shift lens. The image stabilization lens is movable in a direction perpendicular to the optical axis of the imaging device 100. The lens-type image stabilization controller 106 drives and controls the lens-type image stabilization unit 105. The focus unit 107 includes a focus lens that adjusts focus to form a subject image. The focus drive control unit 108 controls the drive of the focus unit 107 .

[0017] The lens operation unit 109 is an operation unit used by the user to operate the interchangeable lens 100a. The lens shake detection unit 110 detects the amount of shake applied to (occurring in) the imaging device 100 or the interchangeable lens 100a and outputs a detection signal to the lens system control unit 111. The lens system control unit 111 is equipped with a CPU (Central Processing Unit) and controls the drive control units and correction control units of the interchangeable lens 100a, thereby controlling the entire interchangeable lens 100a. The lens system control unit 111 communicates with a camera communication control unit 127 of the camera body 100b via the lens communication control unit 112. In other words, when the interchangeable lens 100a is attached to and electrically connected to the camera body 100b, mutual communication takes place between the interchangeable lens 100a and the camera body 100b via the lens communication control unit 112 and the camera communication control unit 127.

[0018] Next, the camera body 100b will be described. The camera body 100b includes a shutter unit 113. A shutter drive control unit 114 controls the drive of the shutter unit 113. The imaging unit 115 includes an imaging element, and performs photoelectric conversion on the optical image formed through each lens group, outputting an electrical signal. The imaging element of the imaging unit 115 is movable in a direction perpendicular to the optical axis of the imaging device 100. The imaging surface image stabilization unit 117 includes an imaging surface image stabilization unit (hereinafter also referred to as an "imaging surface stabilization unit" or "IIS") that corrects image shake by moving the imaging element of the imaging unit 115. The imaging surface image stabilization control unit 116 controls the drive of the imaging surface image stabilization unit 117. The imaging signal processing unit 118 converts the electrical signal output from the imaging unit 115 into a video signal. The video signal processing unit 119 processes the video signal output from the imaging signal processing unit 118 according to the intended use. For example, video signal processing unit 119 changes the cut-out position of the video signal according to the correction amount of electronic image stabilization control unit 125. Electronic image stabilization control unit 125 controls image stabilization by cutting out the image.

[0019] The display unit 120 displays images as needed based on signals output from the video signal processing unit 119. The recording unit 121 stores various data such as video information. The power supply unit 122 supplies power to the entire device depending on the application. The camera operation unit 123 is an operation unit used by the user to operate the camera body 100b, and outputs an operation signal to the camera system control unit 126. The camera shake detection unit 124 detects the amount of shake applied to (occurring in) the imaging device 100 or the camera body 100b, and outputs a detection signal to the camera system control unit 126. The camera system control unit 126 includes a CPU and controls the entire camera body 100b. The camera system control unit 126 communicates with the lens communication control unit 112 of the interchangeable lens 100a via a camera communication control unit 127. That is, when the interchangeable lens 100a is attached to and electrically connected to the camera body 100b, mutual communication is carried out between the interchangeable lens 100a and the camera body 100b via the lens communication control unit 112 and the camera communication control unit 127.

[0020] Next, we will explain the general operation of the imaging device 100. The lens operation unit 109 and camera operation unit 123 each include an image stabilization switch that can select ON / OFF of image stabilization. When the user operates the image stabilization switch to select ON, the lens system control unit 111 and camera system control unit 126 instruct the lens image stabilization control unit 106, the imaging surface image stabilization control unit 116, and the electronic image stabilization control unit 125 to perform image stabilization operations. Each image stabilization control unit continues to control image stabilization until an instruction to turn image stabilization OFF is given.

[0021] The camera operation unit 123 also includes an image stabilization mode switch that allows selection of a first mode or a second mode for image stabilization. The first mode is a mode in which image stabilization is performed by combining optical image stabilization and image-sensing surface image stabilization. The second mode is a mode in which image stabilization is performed by combining optical image stabilization, image-sensing surface image stabilization, and electronic image stabilization. When the first mode is selected, optical image stabilization and image-sensing surface image stabilization are performed in coordination to achieve a wider correction angle and correct larger shakes. The readout position of the imaging unit 115 remains constant, and by widening the readout range accordingly, wider-angle shooting is possible. When the second mode is selected, the cropping range of the video signal by the video signal processor 119 is narrowed, but the cropping position can be changed according to the amount of image stabilization to accommodate larger shakes.

[0022] The camera operation unit 123 includes a shutter release button configured to sequentially turn on a first switch (SW1) and a second switch (SW2) depending on the amount of depression. SW1 turns on when the user presses the shutter release button about halfway, and SW2 turns on when the user presses the shutter release button all the way. When SW1 is turned on, the focus drive control unit 108 drives the focus unit 107 to adjust the focus, and the aperture drive control unit 104 drives the aperture unit 103 to set an appropriate exposure amount. When SW2 is turned on, image data obtained from the light image exposed by the imaging unit 115 is stored in the recording unit 121.

[0023] The camera operation unit 123 also includes a video recording switch. The imaging device 100 starts capturing video after the video recording switch is pressed, and stops recording when the user presses the video recording switch again during recording. When the user operates the shutter release button during video capture to turn on SW1 and SW2, a process is executed to capture and record a still image during video recording. The camera operation unit 123 also includes a playback mode selection switch that allows selection of a playback mode. When playback mode is selected by operating the playback mode selection switch, the imaging device 100 stops the image stabilization operation. Of the lens-type image stabilization unit 105 and the imaging surface image stabilization unit 117 shown in FIG. 1 , the one with higher image stabilization performance functions as a first image stabilization means (hereinafter referred to as the first optical stabilization means), and the other functions as a second image stabilization means (hereinafter referred to as the second optical stabilization means). In this embodiment, both examples will be described, and the explanation will appropriately state which case is assumed.

[0024] Next, the image blur correction control executed by the lens system control unit 111 and the camera system control unit 126 will be described with reference to Fig. 2. Fig. 2 is a block diagram illustrating the control for performing image blur correction by driving the lens type image blur correction unit 105 and the imaging surface image blur correction unit 117 based on shake information applied to the imaging device 100.

[0025] 2, the angular velocity sensor 201 and the A / D converter 202 are included in the lens shake detection unit 110. , Re The lens storage unit 911 and the first correction amount divider 921 are implemented by the lens system control unit 111. The drive amount converter 207, subtractor 208, control filter 209, OIS driver 210, and position sensor 212 are included in the lens-type image stabilization control unit 106. The angular velocity sensor 901 and A / D converter 902 are included in the camera shake detection unit 124. The camera storage unit 912, correction division setting unit 913, and second correction amount divider 922 are implemented by the camera system control unit 126. The drive amount converter 213, subtractor 214, control filter 215, OIS driver 216, and position sensor 218 are included in the imaging surface image stabilization control unit 116.

[0026] In this embodiment, the imaging device 100 acquires the amount of correction for image shake correction using the angular velocity sensor 201 and drives the lens-type image stabilization unit 105. The imaging device 100 also acquires the amount of correction for image shake correction using the angular velocity sensor 901 and drives the imaging surface image stabilization unit 117. Information required to determine the division state and information related to the division state are exchanged via the lens communication control unit 112 and the camera communication control unit 127.

[0027] The angular velocity sensor 201 detects the angular velocity of a shake applied to the image pickup device 100 and outputs a voltage corresponding to the angular velocity. The output voltage of the angular velocity sensor 201 is converted into digital data by an A / D converter 202 and acquired as angular velocity data. 3 The output of the angular velocity sensor 901 is also converted into digital data by an A / D converter 902 and supplied to an image stabilization amount calculation unit 903. The series of processes from acquiring the angular velocity data to driving the image stabilization units 105 and 107 is repeated at a cycle that is sufficiently fast for the camera shake frequency band of 1 to 20 Hz, for example, at a cycle of 1000 Hz.

[0028] The image blur correction amount calculation unit 203 calculates the amount of correction for correcting image blur caused by a shake applied to the imaging device 100. Similarly, the image blur correction amount calculation unit 903 calculates the amount of correction for correcting image blur caused by a shake applied to the imaging device 100. Note that the imaging device 100 includes two image blur correction units: the lens-type image blur correction unit 105 and the imaging surface image blur correction unit 117. However, the correction amounts calculated by the image blur correction amount calculation units 203 and 903 are not the correction amounts for the two image blur correction units, respectively, but are the correction amounts for correcting image blur in the entire imaging device 100.

[0029] FIG. 3 is a block diagram illustrating the details of the image stabilization amount calculation unit 203. The image stabilization amount calculation unit 903 also has the same structure, so only one is shown. The HPF 301 (high-pass filter) is used to remove DC and low-frequency components from the angular velocity data detected by the A / D converter 202. The angular velocity data passed through the HPF 301 is converted into angular displacement data by first-order integration in the integrator 303. The cutoff frequency of the HPF 301 is determined by the characteristics of the angular velocity sensor 201. That is, if the drift (low-frequency fluctuations, also known as random walk) of the angular velocity sensor 201 is large, the cutoff frequency is increased to sufficiently reduce noise. If the drift is small, the cutoff band is lowered to approximate a perfect integration. A smaller drift can improve image stabilization performance. The integration calculation performed here is an imperfect integration to prevent saturation, and is performed using a commonly known first-order LPF (low-pass filter). The angular displacement data calculated by the integrator 303 is supplied to a framing control unit 305 and a limiter 304. The limiter 304 limits the angular displacement data so that the lens-type image stabilization unit 105 and the imaging surface image stabilization unit 117 do not hit the ends of their movable ranges. The angular displacement data limited by the limiter 304 is output to a first correction amount division unit 921 as the output of the image stabilization amount calculation unit 203.

[0030] The framing control unit 305 determines whether a user-intended operation, such as panning or tilting, has been performed, and performs control to return the angular displacement data to the center. In other words, the framing control unit 305 removes shake components due to the user's intended framing of the imaging device 100 from the angular velocity detected by the angular velocity sensor 201 (angular displacement data acquired by the A / D converter 202). This makes it possible to correct image blur caused by camera shake while performing the user's intended framing. Specifically, a predetermined threshold is set further inside the control end of the angular displacement data provided in the limiter 304, and if the angular displacement data output from the integrator 303 exceeds the threshold, it is determined that panning has been performed. If it is determined that panning has been performed, the framing control unit 305 limits the angular velocity data by increasing the cutoff frequency of the HPF 301 to remove more low-frequency components. Alternatively, the framing control unit 305 may subtract an offset from the angular velocity data input to the integrator 303, thereby returning the output of the integrator 303 to the center. Alternatively, the framing control unit 305 may raise the cutoff frequency of the LPF calculation performed by the integrator 303, thereby controlling the output of the integrator 303 to return to the center. By controlling in this manner, it becomes possible to control the lens-type image stabilization unit 105 and the imaging surface image stabilization unit 117 so that they fall within their movable ranges, even when shake intended by the user, such as due to panning or tilting, occurs. The image stabilization amount calculation unit 903 also has the configuration of the image stabilization amount calculation unit 203 described above.

[0031] Returning to Figure 2, the correction division setting unit 913 functions as a division ratio determination means that determines the division ratio between the first optical vibration reduction means and the second optical vibration reduction means based on information regarding the vibration reduction performance and movable range stored in the lens storage means 911 and the camera storage means 912.

[0032] Here, the information stored in the lens storage unit 911 and the camera storage unit 912 will be described. Information about the movable range stores the range over which the lens-type image stabilization unit 105 and the image-sensing surface image stabilization unit 117 can operate (e.g., XX μm, XX pulses), or information that converts that range into the amount of image blur in the captured image (e.g., XX degrees). Furthermore, the vibration isolation performance is information determined from the transfer characteristics from the angular velocity sensors 201, 901 to the lens-type image stabilization unit 105 or the image-sensing surface image stabilization unit 117. This information may be stored in the form of transfer characteristics (frequency response), or it may store numerical values ​​acquired by some testing method. The vibration isolation performance of the interchangeable lens 100a is the performance when the lens-type image stabilization unit 105 corrects the shake detected by the angular velocity sensor 201. This performance is stored in the lens storage unit 911. The vibration isolation performance of the camera body 100b is the performance when the image-sensing surface image stabilization unit 117 corrects the shake detected by the angular velocity sensor 901. This is stored in the lens storage means 911.

[0033] The division information determined by the correction division setting unit 913 is sent to the first correction amount dividing unit 921 and the second correction amount dividing unit 922, and appropriate processing is performed based on the outputs from the image shake correction amount calculation units 203 and 903 and the division information, thereby performing image shake correction. In other words, the correction division setting unit 913 sends the division information to the first correction amount dividing unit 921 and the second correction amount dividing unit 922 and has them set a division ratio, thereby controlling the image shake correction operations of the lens-type image shake correction unit 105 and the imaging surface image shake correction unit 117. Detailed operations of these units will be described later with reference to FIGS. 4 and 5. The correction division setting unit 913, the first correction amount dividing unit 921, and the second correction amount dividing unit 922 constitute division control means for the entire imaging device 100. Furthermore, one of the lens storage unit 911 and the camera storage unit 912 serves as a first storage unit, and the other serves as a second storage unit. For example, the image stabilization unit with higher performance becomes the first storage means. If the lens-type image stabilization unit 105 included in the interchangeable lens 100a has higher vibration isolation performance, the lens storage means 911 becomes the first storage means.

[0034] Fig. 4 is a block diagram showing an example of the configuration of the correction division setting unit 913, the first correction amount division unit 921, and the second correction amount division unit 922 that constitute the division control means. Fig. 4(a) shows an example in which the overall image blur correction amount is divided into the first correction amount and the second correction amount using a gain, and Figs. 4(b) and 4(c) show examples in which the division is performed using a filter.

[0035] 4A, a multiplier 401 multiplies the image blur correction amount calculated by the image blur correction amount calculation unit 203 by a first magnification K1 determined by the correction division setting unit 913, and outputs a first correction amount. Here, K1 is 0≦K1≦1 (Formula 1) The image blur correction amount multiplied by the first magnification K1 by the multiplier 401 becomes the first correction amount, which is the correction amount when the lens-type image blur correction unit 105 performs image blur correction.

[0036] Similarly, the multiplier 402 multiplies the image blur correction amount calculated by the image blur correction amount calculation unit 903 by the second magnification K2 determined by the correction division setting unit 913, and outputs the second correction amount. Here, K2 is expressed as follows: K1+K2=1...(Formula 2) The image blur correction amount multiplied by the second magnification K2 by the multiplier 402 becomes the second correction amount, which is the correction amount when the imaging surface image blur correction unit 117 performs image blur correction.

[0037] As is clear from (Equation 2), the first correction amount and the second correction amount are divided so that the sum of them becomes the correction amount for image blur correction for the entire apparatus.

[0038] Although Fig. 4(a) shows an example in which the image blur correction amount is divided at a predetermined ratio (K1:K2), it may be divided by frequency band. Fig. 4(b) and (c) show an example in which the image blur correction amount is divided by frequency band. Setting section 913 An example of the configuration is shown below.

[0039] In FIG. 4B, the HPFs 403a and 403b pass only the high frequency band. The HPFs 403a and 403b have the same characteristics. The HPF 403a passes only the high frequency band of the image blur compensation amount calculated by the image blur compensation amount calculation unit 203, and calculates it as a first compensation amount. Similarly, the HPF 403b passes only the high frequency band of the image blur compensation amount calculated by the image blur compensation amount calculation unit 903. The subtractor 404 extracts a second compensation amount (low frequency component) by subtracting the amount calculated by the HPF 403b (high frequency component).

[0040] Generally, low-frequency components are dominant in shakes that affect the imaging device 100. Therefore, between the lens-type image stabilization unit 105 and the image sensor surface image stabilization unit 117, the one with the higher image stabilization performance (hereinafter referred to as "shake reduction performance") can be allocated to the low-frequency components. That is, in the example of FIG. 4(b), the image sensor surface image stabilization unit 117, which is driven by the second correction amount, serves as the first optical stabilization means with relatively higher shake reduction performance. If the lens-type image stabilization unit 105 has higher performance, the configurations of the first correction amount divider 921 and the second correction amount divider 922 can be swapped.

[0041] Furthermore, by using the configuration shown in FIG. 4(b), the correction amount is divided so that the sum of the first correction amount and the second correction amount becomes the correction amount for image blur correction of the entire apparatus.

[0042] In FIG. 4(c), the LPFs 405a and 405b pass only low-frequency components. The LPFs 405a and 405b have the same characteristics. The LPF 405a passes only low-frequency components of the image blur correction amount calculated by the image blur correction amount calculation unit 203, and calculates the amount as a first correction amount. Similarly, the LPF 405b passes only low-frequency components of the image blur correction amount calculated by the image blur correction amount calculation unit 903. The subtractor 406 extracts a second correction amount (high-frequency components) by subtracting the amount (low-frequency components) calculated by the LPF 405b. In other words, the example in FIG. 4(c) illustrates an example in which the lens-type image blur correction unit 105, driven by the first correction amount, serves as a first optical image stabilization unit with relatively high image stabilization performance. As in FIG. 4B, if the imaging surface image blur correction unit 117 has higher performance, the configurations of the first correction amount divider 921 and the second correction amount divider 922 may be interchanged.

[0043] Furthermore, by using the configuration shown in FIG. 4(c), the correction amount is divided so that the sum of the first correction amount and the second correction amount becomes the correction amount for image blur correction of the entire apparatus.

[0044] The operation of the division control means will be described in more detail. As described above, in the example of Fig. 4(a), division is performed at an appropriate ratio using the multiplier 401 and the first multiplier K1. The method of determining the first multiplier K1 in the corrected division setting unit 913 will be described.

[0045] If the image stabilization performance of the lens-type image stabilization unit 105 and the image sensor-side image stabilization unit 117 is equal, then the division should be based on the ratio of the image shake correction amount at the image plane between the lens-type image stabilization unit 105 and the image sensor-side image stabilization unit 117. That is, if the correction amount is equal, the same ratio (K1 = K2 = 0.5) is used. If the correction amount of one of them is greater, the first magnification and the second magnification are determined based on that ratio. For example, if the lens-type image stabilization unit has a greater correction amount, then K1 > 0.5 and K2 < 0.5. By setting them in this way, it is possible to fully utilize the correction amount and suppress image shake even when a large shake is applied.

[0046] On the other hand, the image stabilization performance of the lens-type image stabilization unit 105 is generally not the same as that of the imaging surface image stabilization unit 117. Specifically, the transfer characteristics of the system formed by the subtractor 208, control filter 209, OIS driver 210, lens-type image stabilization unit 105, and position sensor 212 (frequency response of the lens-type image stabilization unit) and the transfer characteristics of the system formed by the subtractor 214, control filter 215, OIS driver 216, Image stabilization unit 117 , and the position sensor 218 do not match. This is because the mass of the moving parts and the type of actuator are different, so the same correction performance cannot be achieved even when the control filters 209 and 215 are used.

[0047] As already mentioned, the performance of angular velocity sensors 201, 901 may not be the same. The vibration isolation performance, which is determined by the performance from shake detection to position control of the correction unit, is stored in lens storage means 911 and camera storage means 912. Additionally, information regarding the range of movement of lens-type image stabilization unit 105 is stored in lens storage means 911, and information regarding the range of movement of imaging surface image stabilization unit 117 is stored in camera storage means 912.

[0048] As an example, let us consider a case where the interchangeable lens 100a has higher image stabilization performance. In this case, the lens-type image stabilization unit 105 corresponds to the first optical image stabilization means, the imaging surface image stabilization unit 117 corresponds to the second optical image stabilization means, the lens storage means 911 corresponds to the first storage means, and the camera storage means 912 corresponds to the second storage means.

[0049] When focusing only on the movable range, it is preferable to divide the amount of image blur correction (output of image blur correction amount calculation units 203, 903) corrected by the entire imaging device 100 in the ratio of the movable range converted into the amount of image blur (hereinafter referred to as the vibration reduction range). For example, if the vibration reduction range of lens-type image blur correction unit 105 and the vibration reduction range of imaging surface image blur correction unit 117 have a ratio of 3:7, moving them at that ratio can easily accommodate even large shakes. This division method is the first division ratio that maximizes the range in which image blur correction is possible (hereinafter referred to as the vibration reduction range).

[0050] On the other hand, if the image stabilization range is ignored and focus is placed solely on image stabilization performance, it is preferable to selectively use the one with higher image stabilization performance (a frequency response with a gain of 1 and a phase of close to 0 deg relative to the shake acting on the image capture device 100). This division method is the second division ratio that maximizes image stabilization performance.

[0051] It should be noted here that when the first division ratio is selected, image stabilization performance is reduced compared to the second division ratio when small shakes are present. The degree of reduction is determined by the ratio of the respective image stabilization performances. Furthermore, when large shakes are present, if the second division ratio is selected and only the first optical image stabilization means is used, the amount of compensation that can be performed falls short, resulting in reduced image stabilization performance.

[0052] As described above, the first division ratio and the second division ratio are appropriate when focusing on the magnitude of shake and the vibration isolation performance, respectively. From the viewpoint of the magnitude of shake, it is preferable to use the second division ratio when the shake is small, and the first division ratio when the shake is large. Split It is desirable to use a ratio between these two. However, depending on the shooting conditions, it may be desirable to use a third division ratio between these ratios. For example, this may be the case when the second division ratio, which focuses only on image stabilization performance, results in a slightly insufficient image stabilization range, while the first division ratio, which focuses only on image stabilization range, results in a margin of error in the image stabilization range, resulting in a noticeable decrease in image stabilization performance.

[0053] A method for determining the division ratio (hereinafter referred to as the final division ratio) actually used to control the lens type image stabilization unit 105 and the imaging surface image stabilization unit 117 will be explained using FIG. 5. FIGS. 5(a) and 5(b) show the final division ratio when division is performed using gain, and correspond to the division method in FIG. 4(a). c ) indicates the final division ratio when dividing using a filter, and corresponds to the division methods in Figures 4(b) and (c).

[0054] Fig. 5(a) is a table showing an example of how to set K1 and K2 when the interchangeable lens 100a has relatively high vibration isolation performance and the values ​​are divided at a predetermined ratio. The value to the left of the slash ( / ) indicates the value of K1, and the value to the right indicates the value of K2. Fig. 5(b) is a table showing an example of how to set K1 and K2 when the image pickup surface image stabilization unit 117 has relatively high vibration isolation performance and the values ​​are divided at a predetermined ratio. The value to the left of the slash ( / ) indicates the value of K1, and the value to the right indicates the value of K2.

[0055] The columns marked with a circle in the table are the division ratios that maximize the vibration isolation range, which is the first division ratio described above. The columns marked with a black circle are the division ratios that maximize the vibration isolation performance, which is the second division ratio described above. The other columns are ratios between the first and second division ratios, which is the third division ratio described above.

[0056] If the amount of image blur occurring during exposure is small, image blur will occur if image blur correction is not performed, but a large image stabilization range is not necessary; a small image stabilization range is sufficient. Therefore, the second division ratio is set as the final division ratio, and the ratio with higher image stabilization performance is selectively operated. In the example of FIG. 5(a), if the exposure time is 1 / 60 [s] or less and the focal length is 70 mm or less, or if the exposure time is 1 / 60 to 1 / 15 [s] and the focal length is 24 mm or less, it is determined that image blur occurring during exposure is small, and the first magnification K1 = 1 and the second magnification K2 = 0 are set. As a result, image blur correction is performed only by the interchangeable lens 100a, which has relatively high image stabilization performance, resulting in high image stabilization performance.

[0057] On the other hand, if the image blurring that occurs during exposure is large, the second Split It is expected that the image stabilization range will be insufficient at this ratio. In this case, it is expected that the insufficient image stabilization range will result in a larger residual image blur than a relative decrease in image stabilization performance. Therefore, the first division ratio is set as the final image stabilization ratio, and the image stabilization range is widened. In the example of FIG. 5(a), if the exposure time is 4 seconds or longer and the focal length is 70 mm or longer, or if the exposure time is 1 to 4 seconds and the focal length is 200 mm or longer, it is determined that the image blur occurring during exposure is large, and the first magnification K1 = 0.3 and the second magnification K2 = 0.7 are set. This magnification ratio can be obtained by reading information indicating the image stabilization range stored in the lens storage means 911 and the camera storage means 912, and determined based on this information. This ensures a large image stabilization range, allowing appropriate image stabilization even when large blur occurs.

[0058] Under other conditions, the third division ratio between the first and second division ratios is set as the final division ratio while maintaining K1 + K2 = 1 in (Equation 2). This ensures an image stabilization range that corresponds to the amount of image blur that is expected to occur during exposure, and also realizes control that makes the most of image stabilization performance.

[0059] In the example of FIG. 5(a), focal length and exposure time are shown as shooting conditions. The correction division setting unit 913 functions as a shooting condition acquisition unit that acquires these shooting conditions and determines the final division ratio in the table based on this information. The longer the focal length, the greater the image blur. The longer the exposure time, the greater the image blur. Other factors that govern the amount of image blur include the imaging magnification of the shooting optical system and the state of camera shake that acted on the camera prior to the shooting. The greater the imaging magnification, the greater the image blur. The state of camera shake that acted on the camera prior to the shooting is a method of analyzing the shake acting on the imaging device 100 prior to exposure and predicting the image blur that will occur during exposure based on its magnitude. As a simple example, when the imaging device 100 is mounted on a tripod, almost no shake is observed, so the image blur that will occur during exposure is predicted to be small. When shooting with the imaging device 100 held by hand, the magnitude of the photographer's so-called hand shake is observed, and an appropriate division ratio is selected based on that magnitude.

[0060] FIG. 5(b) is a table showing example settings for K1 and K2 when dividing at a predetermined ratio when the camera body 100b has relatively high anti-shake performance. As in FIG. 5(a), the columns marked with a circle in the table are division ratios that maximize the anti-shake range, and are the first division ratio described above. The columns marked with a black circle are division ratios that maximize the anti-shake performance, and are the second division ratio described above. The other columns are between the first and second division ratios. in This is the third division ratio mentioned above.

[0061] As explained in FIG. 5A, if the amount of image blur occurring during exposure is small, a small image stabilization range is sufficient, and the second division ratio is set as the final division ratio, and the camera with higher image stabilization performance (here, camera body 100b) is selectively operated. If the amount of image blur occurring during exposure is large, a relatively lower image stabilization performance is acceptable, and the first division ratio is set as the final division ratio, and operation is performed to widen the image stabilization range. In the example of FIG. 5B, the first magnification K1 is set to 0.6 and the second magnification K2 is set to 0.4. Under other conditions, while maintaining K1 + K2 = 1 in (Equation 2), a third division ratio between the first and second division ratios is set as the final division ratio. This ensures an image stabilization range appropriate for the amount of image blur expected to occur during exposure, while also achieving control that makes the most of image stabilization performance.

[0062] Figure 5(c) is an example using a filter. The values ​​in the table are the cutoff frequencies of the LPF / HPF filters. First, we will explain the case where Figure 5(c) and Figure 4(b) are used in combination. In Figure 4(b), the division ratio is determined using an HPF.

[0063] As in Figure 5(a), the columns marked with a circle in the table are the division ratios that maximize the vibration isolation range, and are designated as the first division ratio. The columns marked with a black circle are the division ratios that maximize the vibration isolation performance, and are designated as the second division ratio. The other columns are between the first and second division ratios, and are designated as the third division ratio.

[0064] If the image blur occurring during exposure is small, a small vibration-reduction range is sufficient, so the second division ratio is set as the final division ratio, and the higher vibration-reduction performance is selectively operated. In the example of FIG. 5(c), similar to FIG. 5(a), image blur occurring during exposure is determined to be small when the exposure time is 1 / 60 [s] or less and the focal length is 70 mm or less, or when the exposure time is 1 / 60 to 1 / 15 [s] and the focal length is 24 mm or less. Under these shooting conditions, the cutoff frequency is set to 50 Hz. Most vibrations acting on the imaging device 100 occur at frequencies lower than 50 Hz. Therefore, the first correction amount in FIG. 4(b) is almost zero, and vibration reduction is achieved solely by the second correction amount. This allows vibration reduction almost entirely by the camera body 100b, which has relatively high vibration-reduction performance, resulting in high vibration-reduction performance.

[0065] On the other hand, if the image blur occurring during exposure is significant, a relative decrease in image stabilization performance is acceptable; therefore, the first division ratio is set as the final division ratio, and operation is performed to widen the image stabilization range. In the example of FIG. 5(c), if the exposure time is 4 seconds or longer and the focal length is 70 mm or longer, or if the exposure time is 1 to 4 seconds and the focal length is 200 mm or longer, it is determined that the image blur occurring during exposure is significant, and the cutoff frequency is set to 1 Hz. As a result, the first correction amount in FIG. 4(b) corresponds to shake of 1 Hz or more, and the second correction amount corresponds to shake of 1 Hz or less. Generally, the shake components acting on the image capture device 100 when a person holds the camera are known, so the ratio of the correction amounts can be adjusted by adjusting the cutoff frequency. The cutoff frequency may be determined based on information indicating the image stabilization range stored in the lens storage unit 911 and the camera storage unit 912. This ensures a large image stabilization range, ensuring appropriate image stabilization even when significant shake occurs.

[0066] Under other conditions, the system operates at a third division ratio between the first and second division ratios while maintaining K1 + K2 = 1 in (Equation 2). This ensures an image stabilization range that corresponds to the amount of image blur that is likely to occur during exposure, and also achieves control that makes the most of image stabilization performance.

[0067] Finally, we will explain the case where Figure 5(c) and Figure 4(c) are used in combination. The columns marked with a circle in the table are the division ratios that maximize the image stabilization range, and are the first division ratios. The columns marked with a black circle are the division ratios that maximize the image stabilization performance, and are the second division ratios. The other columns are between the first and second division ratios, and are the third division ratios.

[0068] If the image blur occurring during exposure is small, the vibration reduction range can be small, so the second division ratio is set as the final division ratio, and the ratio with higher vibration reduction performance is selectively operated. In the example of FIG. 5(c), the cutoff frequency is set to 50 Hz. Most vibrations acting on the imaging device 100 occur at frequencies lower than 50 Hz. Therefore, the second correction amount in FIG. 4(c) becomes almost zero, and vibration reduction is performed using only the first correction amount. As a result, vibration reduction is performed almost exclusively by the interchangeable lens 100a, which has relatively high vibration reduction performance, resulting in high vibration reduction performance.

[0069] On the other hand, if the image blur that occurs during exposure is large, it is acceptable for image stabilization performance to be relatively reduced, so the first division ratio can be used as the final division ratio to operate so as to widen the image stabilization range. Under the conditions marked with a circle, the cutoff frequency is set to 1 Hz. As a result, the first correction amount in Figure 4(c) corresponds to vibrations of 1 Hz or less, and the second correction amount corresponds to vibrations of 1 Hz or more.

[0070] Under other conditions, the system operates at a third division ratio between the first and second division ratios while maintaining K1 + K2 = 1 in (Equation 2). This ensures an image stabilization range that corresponds to the amount of image blur that is likely to occur during exposure, and also achieves control that makes the most of image stabilization performance.

[0071] The effect of using the third division ratio as the final division ratio will be explained using Fig. 6. Fig. 6 is a graph showing the relationship between the amount of shake acting on the imaging device 100 (hereinafter referred to as shake amount) and the amount of image blur occurring in a captured image. When image shake correction is performed, the graph shows the amount of image blur that could not be corrected (hereinafter referred to as residual image blur amount). The horizontal axis of Fig. 6 indicates the magnitude of shake acting on the imaging device 100 during exposure. The vertical axis indicates the amount of image blur occurring in a captured image due to shake.

[0072] Using FIG. 6(a), we will explain the relationship between the difference in image stabilization performance between the first and second optical image stabilization units and the amount of remaining image blur. Line 1001 represents the case where no image stabilization is performed, line 1002 represents the case where image stabilization is performed using only the second optical image stabilization unit, which has relatively low image stabilization performance, and line 1003 represents the case where image stabilization is performed using only the first optical image stabilization unit, which has relatively high performance. In FIG. 6(a), the slope of line 1002 is half that of line 1001, meaning that the amount of image blur can be reduced by half compared to when image stabilization is not performed (a state where the image stabilization effect is referred to as one step according to the CIPA standard). Line 1003 has a slope that is one-eighth that of line 1001, meaning that the amount of image blur can be reduced by one-eighth compared to when image stabilization is not performed (a state where the image stabilization performance is referred to as three steps).

[0073] In FIG. 6(a), when a shake amount 1004 acts during exposure, an image blur amount 1001a occurs if image stabilization is not performed. Similarly, when image stabilization is performed using the second optical image stabilization means, an image blur amount 1002a occurs, and when image stabilization is performed using the first optical image stabilization means, an image blur amount 1003a cannot be corrected and remains. Clearly, image blur amounts 1002a and 1003a are smaller than image blur amount 1001a, and the amount of image blur is reduced with image stabilization compared to when image stabilization is not performed. This is the effect of image stabilization. Furthermore, image blur amount 1003a is smaller than image blur amount 1002a, and the amount of remaining image blur is reduced when the first optical image stabilization means, which has relatively high performance, is used. This is the difference in image stabilization performance.

[0074] The influence of the vibration isolation range of the vibration isolation device and the drive ratio will be explained using FIG. 6(b). In FIG. 6(b), the vibration isolation range 1005 of the first optical vibration isolation means, which has a relatively high vibration isolation performance, is narrower than the vibration isolation range 1006 of the second optical vibration isolation means. Vibration isolation Range and second optical vibration isolation means Vibration isolation The combined range is indicated as an image stabilization range 1007. Polygonal lines 1010a and 1010b show the relationship between the amount of shake and the amount of image blur when only the first optical image stabilization means is used. Polygonal lines 1020a and 1020b show the relationship between the amount of shake and the amount of image blur when only the second optical image stabilization means is used. Dashed lines 1010c and 1020c respectively show the relationship between the amount of shake and the amount of image blur when only the first optical image stabilization means is used without considering the image stabilization range, and the relationship between the amount of shake and the amount of image blur when only the second optical image stabilization means is used. Dashed line 1010c corresponds to the straight line 1003 in FIG. 6(a). and The dashed line 1020c has the same slope as the straight line 1002. The states of the dashed lines 1010c and 1020c cannot actually be realized due to the lack of an anti-vibration range.

[0075] Points 1011 and 1021 indicate the points where the vibration isolation ranges of the first optical vibration isolation means and the second optical vibration isolation means have been used up, respectively. A line 1031 is a line drawn from point 1011 with the same gradient as line 1020a, point 1032 is the intersection of line 1031 and the range of line 1007, and line 1030 is the origin. point The line connecting point 1032 is point 1033. 1030 and line 1010b.

[0076] In the explanation of FIG. 6(a), the vibration isolation range of the optical vibration isolation means was ignored. However, in reality, the vibration isolation range is finite, as shown in FIG. 6(b). For example, if a shake larger than the vibration isolation range 1005 of the first optical vibration isolation means acts, vibration isolation cannot be achieved by the first optical vibration isolation means alone. Therefore, the straight line 1010a is bent at point 1011, and the slope of the straight line 1010b for shakes larger than this is the same as the slope of the straight line 1001 when no vibration isolation is performed. As a result, the amount of image blur when only the first optical vibration isolation means is used is as shown by the bent lines 1010a and 1010b.

[0077] Similarly, when only the second optical image stabilization means is used, the straight line 1020a is broken at point 1021, and for shakes larger than this, the slopes of the straight lines 1020b and 1001 are the same. As a result, the amount of image blur when only the second optical image stabilization means is used is as shown by the broken lines 1020a and 1020b. As already explained, the broken lines 1010c and 1020c cannot be realized because they are outside the image stabilization range.

[0078] In the example of Figure 6(b), the ratio between the image stabilization range 1005 of the first optical image stabilization means and the image stabilization range 1006 of the second optical image stabilization means is 0.33:0.67 (=1:2). This corresponds to the first division ratio. A straight line 1030 shows the relationship between the amount of shake and the amount of image blur when the first and second optical image stabilization means are operated at this ratio.

[0079] The second division ratio, which is the ratio that can maximize image stabilization performance when the image stabilization range is ignored, is the case when the first optical image stabilization means is used exclusively, and the ratio is 1:0. The relationship between the amount of shake and the amount of image blur in this case is shown by broken lines 1010a and 1010b.

[0080] In FIG. 6(b), the image pickup device is subjected to a shake amount 1005 (= the amount of the first optical vibration reduction means Vibration isolationConsider a case where the shake amount 1005 is applied. In this case, the amount of image blur 1051 at the second division ratio, which selectively uses the first optical image stabilization means, is smaller than the amount of image blur 1052 when the second optical image stabilization means is selectively used. Furthermore, the amount of image blur 1051 when the first optical image stabilization means is selectively used is smaller than the amount of image blur 1053 at the first division ratio, which maximizes the image stabilization range. In this way, it can be seen that when the shake amount 1005 is applied, it is appropriate to operate at the second division ratio (to maximize image stabilization performance).

[0081] Next, in FIG. 6(b), the image pickup device is subjected to a shake amount 1007 (= the amount of the first optical vibration reduction means Vibration isolation Range + Secondary Optical Stabilizer Vibration isolation Consider a case where the shake amount 1007 acts on the second optical image stabilization means. In this case, the amount of image blur 1042 when the second optical image stabilization means is used alternatively is smaller than the amount of image blur 1041 when the second optical image stabilization means is used alternatively at the second division ratio. Furthermore, the amount of image blur 1043 when the first division ratio, which maximizes the image stabilization range, is smaller than the amount of image blur 1042 when the second optical image stabilization means is used alternatively. In this way, it can be seen that when the shake amount 1007 acts, it is appropriate to operate at the first division ratio (to maximize image stabilization performance).

[0082] As explained in Figure 6(b), Vibration isolation When the range is limited, it is found that it is appropriate to provide an appropriate division ratio according to the magnitude of the shake acting on the imaging device. Also, the broken lines 1020a and 1020b, which selectively use only the second optical image stabilization means with relatively low performance, always correspond to the straight line indicating the first division ratio. 1030 It can be seen that the amount of image blur is larger than in (a), and this is not an appropriate allocation of operations. Therefore, to avoid complicating the illustration, this option is omitted in the explanation of FIG. 6(c).

[0083] The method described in Patent Document 2 will be explained using FIG. 6(b). Patent Document 2 discloses that, when multiple image stabilization units are used, the image stabilization unit with the best performance is primarily activated, and the other units are activated when the stroke end is approached. When this operation is properly implemented, the relationship between the amount of shake and the amount of image blur becomes the origin → point 1011 → (along line 1031) → point 1032. This minimizes the amount of image blur. However, this method requires nonlinear processing near point 1011. If the shake acts in a complex manner across this boundary, proper operation may be hindered by nonlinear processing such as communication delays, starting and stopping, and the response of the correction unit. Furthermore, it is necessary to constantly monitor the approach to the end of the image stabilization range and quickly switch processing. This processing requires a lot of resources and is not easy for general embedded devices. Therefore, this embodiment proposes a method that changes the final division ratio according to the shooting conditions, which is simpler than the method described in Patent Document 2 and can reduce the amount of remaining image blur more than a method using only the first and second division ratios.

[0084] 6(c) shows an example in which the third division ratio is appropriate. A straight line 1110 indicates the relationship between the amount of shake and the amount of image blur when the first and second optical image stabilization means are operated at the third division ratio.

[0085] In the example of FIG. 6(c), the third division ratio is shown as a ratio of the first optical image stabilization means to the second optical image stabilization means = 1:1. In this case, the slope of line 1110 is a value between the slopes of lines 1010a and 1020a described in FIG. 6(b). Also, because the ratio of the first division ratio is 1:2, the line has a slope smaller than line 1030. The exact slope can be calculated from the amount of image blur and the division ratio. For example, if the ratio is 1:1, then the slope 1 / 2 and the slope 1 / 8 are combined to give 1 / 2 x 1 / 2 + 1 / 8 x 1 / 2 = 5 / 16. If the ratio is 1:2, then the slope is 1 / 2 x 2 / 3 + 1 / 8 x 1 / 3 = 3 / 8 = 6 / 16.

[0086] When vibration 1100 acts, the image blur amount 1101 when operated at the second division ratio and the first division ratio are SplitThe amount of image blur 1104 when operating at the third division ratio is smaller than the amount of image blur 1103 when operating at the first division ratio. In other words, when operating at the third division ratio, the image blur reduction performance is higher than when operating at the first or second division ratio. This is the effect of using the third division ratio. When there are multiple image blur reduction means, it is possible to perform appropriate image blur reduction using a simple method and obtain high performance.

[0087] Returning to FIG. 2, the drive amount conversion unit 207 converts the correction amount (correction amount on the image plane, correction angle) output from the first correction amount division unit 921 into a movement amount required for the lens-type image stabilization unit 105 to appropriately perform image stabilization, and outputs the converted amount as a drive target position. The position sensor 212 detects position information of the lens-type image stabilization unit 105. The subtractor 208 calculates deviation data by subtracting the position information of the lens-type image stabilization unit 105 from the drive target position. The deviation data is input to a control filter 209, where it is subjected to various signal processing such as gain amplification and phase compensation, and then supplied to an OIS drive unit 210. The OIS drive unit 210 drives the lens-type image stabilization unit 105 in accordance with the output of the control filter 209. This causes the correction optical system to move in a direction perpendicular to the optical axis. The position information of the moved lens-type image stabilization unit 105 is then detected again by the position sensor 212, and the next deviation data is calculated. That is, a feedback loop is formed, and the lens-type image stabilization unit 105 is controlled so that the difference between the drive target position and the position information becomes small, thereby enabling the correction optical system to be driven to follow the drive target position.

[0088] The drive amount converter 213 converts the second correction amount output from the second correction amount divider 922 into a movement amount for appropriately performing image blur correction in the imaging surface image blur correction unit 117, and outputs it as a drive target position. The position sensor 218 detects position information of the imaging surface image blur correction unit 117. The subtractor 214 calculates deviation data by subtracting the position information of the imaging surface image blur correction unit 117 from the drive target position. The deviation data is input to a control filter 215, where it is subjected to various signal processing such as gain amplification and phase compensation, and then supplied to an IIS driver 216. The IIS driver 216 drives the imaging surface image blur correction unit 117 in accordance with the output of the control filter 215. This causes the imaging surface to move in a direction perpendicular to the optical axis.

[0089] In this way, lens-type image stabilization unit 105 and imaging surface image stabilization unit 117 operate in a cooperative manner to share and correct the image shake corresponding to the shake of the entire device. This cooperative operation makes it possible to expand the correctable range of image stabilization. Even when only one of the correction units is used selectively, this is broadly referred to as cooperation, with a division ratio of 1:0.

[0090] As described above, according to the first embodiment, when an imaging device includes a plurality of image stabilization units, cooperative image blur correction can be performed at a division ratio determined according to the shooting conditions.

[0091] This makes it possible to provide an image blur control device that can achieve high vibration isolation performance overall.

[0092] Furthermore, image blur correction can be performed in cooperation with the division ratio that takes into account the image stabilization range and the division ratio that takes into account the image stabilization performance (third division ratio). This makes it possible to provide an image blur control device that can achieve high image stabilization performance overall.

[0093] In this embodiment, the correction division setting unit 913 is located in the camera body 100b, but it may also be provided in the interchangeable lens 100a. Also, in this embodiment, the correction division setting unit 913 that acquires the final division ratio also functions as a means for acquiring a first division ratio and a means for acquiring a second division ratio based on information acquired from the lens storage means 911 and the camera storage means 912. However, these may also be configured as separate blocks.

[0094] [Second embodiment] Next, a second embodiment will be described. In this embodiment, the basic configuration of the imaging device 100 is the same as that of the first embodiment (see FIG. 1). Below, differences from the first embodiment will be mainly described.

[0095] In the first embodiment, a configuration was described in which interchangeable lens 100a acquires the image blur correction amount for the entire imaging device using angular velocity sensor 201 within the interchangeable lens, and camera body 100b acquires the image blur correction amount for the entire imaging device using angular velocity sensor 901 within the camera body. Furthermore, in the first embodiment, a configuration was described in which the acquired entire image blur correction amount is divided by first correction amount divider 921 and second correction amount divider 922, thereby causing lens-type image blur correction unit 105 and imaging surface image blur correction unit 117 to cooperate and perform image blur correction.

[0096] On the other hand, in the second embodiment, a configuration will be described in which an angular velocity sensor 901 provided in camera body 100b is used to obtain the correction amount () for driving each image blur correction unit. Camera body 100b controls image blur correction by lens-type image blur correction unit 105 by transmitting a first correction amount to interchangeable lens 100a. Camera body 100b also controls the imaging surface image blur correction unit using a second image blur correction amount calculated in camera body 100b. At this time, the first and second image blur correction amounts are set so that the sum total becomes 1 (in other words, equal to the output of image blur correction amount calculation section 903).

[0097] 7 is a block diagram illustrating image stabilization control according to the second embodiment. Compared to FIG. 2, this differs in that it does not include a first correction amount divider 921, but instead includes a correction amount divider 2000. Another difference is that although the interchangeable lens 100a includes an angular velocity sensor 201, an A / D converter 202, and an image stabilization amount calculator 203, these are not used to control the image stabilization operation and are therefore not connected to other blocks.

[0098] 7, the correction amount divider 2000 is implemented by the camera system control unit 126. The correction division setting unit 913 and the correction amount divider 2000 constitute the division control means of this embodiment. Also in Fig. 7, the drive amount converter 207 receives the drive amount (first correction amount) from the correction amount divider 2000 via the camera communication control unit 127 and the lens communication control unit 112, and operates the lens-type image stabilization unit 105.

[0099] 8 is a block diagram showing an example of the configuration of the correction division setting unit 913 and the correction amount division unit 2000 that constitute the division control means. 2000 has the functions of the first correction amount division unit 921 and the second correction amount division unit 922 in the first embodiment, and divides the image blur correction amount for the entire imaging device into a first correction amount and a second correction amount. Fig. 8(a) shows an example of division using a gain, and Figs. 8(b) and (c) show examples of division using a filter.

[0100] In FIG. 8A, a multiplier 2001 multiplies the image blur correction amount calculated by the image blur correction amount calculation unit 903 by a first magnification K1 determined by a correction division setting unit 913, and outputs a first correction amount. Here, the first magnification K1 is a magnification that satisfies (Equation 1), as in the first embodiment. The image blur correction amount multiplied by the first magnification K1 by the multiplier 2001 becomes the first correction amount used for image blur correction in the lens-type image blur correction unit 105. A subtractor 2002 calculates a second correction amount by subtracting the amount calculated by the multiplier 2001 (first correction amount) from the correction amount for the entire imaging apparatus calculated by the image blur correction amount calculation unit 903. The first correction amount and the second correction amount are divided so that their sum becomes the correction amount for image blur correction for the entire apparatus. As in the first embodiment, the first correction amount and the second correction amount may be obtained using the first magnification K1 and the second magnification K2 (K2=1−K1).

[0101] 8(a) shows an example in which the image blur correction amount is divided at a predetermined ratio, but it may also be divided by frequency band. Figures 8(b) and 8(c) show configuration examples of the correction amount dividing unit 2000 when the image blur correction amount is divided by frequency band.

[0102] In FIG. 8B, the HPF 2003 passes only the high-frequency band. The HPF 2003 passes only the high-frequency band of the image blur correction amount calculated by the image blur correction amount calculation unit 903 and acquires it as a first correction amount. The subtractor 2004 extracts a second correction amount (low-frequency component) by subtracting the first correction amount (high-frequency component) acquired by the HPF 2003 from the correction amount for the entire image capture device. As in the first embodiment, the low-frequency component can be assigned to either the lens-type image blur correction unit 105 or the image capture surface image blur correction unit 117, whichever has better image stabilization performance. FIG. 8C has a similar configuration except that the filter is an LPF 2005. The second correction amount (high-frequency component) is extracted by subtracting the first correction amount (low-frequency component) acquired by the LPF 2005 from the correction amount for the entire image capture device.

[0103] With this configuration, the total correction amount can be divided into the first correction amount and the second correction amount based on the final division ratio, as in the first embodiment, and therefore the image blur correction of the lens-type image blur correction unit 105 and the imaging surface image blur correction unit 117 can be controlled based on the final division ratio.

[0104] The method for obtaining the final division ratio is the same as in the first embodiment. That is, a first division ratio that maximizes the image stabilization range according to the camera's shooting conditions, a second division ratio that maximizes image stabilization performance, or a third division ratio between the first and second division ratios is selected according to the shooting conditions. As in the first embodiment, if the amount of image blur is predicted to be small and it is desired to maximize image stabilization performance, the second division ratio is set as the final division ratio, and the ratio with higher image stabilization performance is selectively operated. Note that if the image stabilization performance is considered to be the same, operation at 1:1 is sufficient. Also, if the amount of image blur is predicted to be large and it is desired to maximize the image stabilization range, the first division ratio is set as the final division ratio. The third division ratio between the first and second division ratios is set as the final division ratio according to the magnitude of the shake predicted to affect the image capture device 100. As a result, when an image capture device includes multiple image stabilization units, it is possible to appropriately perform image stabilization using a simple method and achieve high overall image stabilization performance.

[0105] In this embodiment, the correction division setting section 913 and the correction amount dividing section 2000 are provided in the camera body 100b, but they may also be provided in the interchangeable lens 100a.

[0106] In addition, in the configuration of this embodiment (FIG. 7), angular velocity sensors 201 and 901 are provided in both the camera body 100b and the interchangeable lens 100a, but the control system is configured using only angular velocity sensor 901. The other angular velocity sensor 201 may also be used.

[0107] More preferably, which of the angular velocity sensors 201, 901 to use may be switched based on information from the lens storage unit 911 and the camera storage unit 912. That is, as described in the first embodiment, the image blur correction amount calculation units 203, 903 include the HPF 701 (see FIG. 3 ), and the characteristics of this filter are determined by the performance of the angular velocity sensors 201, 901. Therefore, information related to the performance of the angular velocity sensors 201, 901, such as the cutoff frequency of the HPF, is stored in the lens storage unit 911 and the camera storage unit 912. With this configuration, the lower the cutoff frequency of the HPF 701, the higher the performance of the angular velocity sensor can be considered, so the information from the angular velocity sensor with the higher performance should be input to the correction amount division unit 2000.

[0108] [Third embodiment] Next, a third embodiment will be described. In this embodiment, the basic configuration of the imaging device 100 is the same as that of the first embodiment (see FIGS. 1 and 2). Below, differences from the first embodiment will be mainly described.

[0109] In the first embodiment, the image stabilization ranges of the respective image stabilization means are acquired from the lens storage means 911 and the camera storage means 912, and a first division ratio that maximizes the image stabilization range is acquired. This embodiment differs from the first embodiment in that the first division ratio is determined in advance and stored in the storage means of either the interchangeable lens 100a or the camera body 100b, whichever has the correction division setting unit 913. The imaging device 100 is an imaging system that uses a combination of the interchangeable lens 100a and the camera body 100b. Various lens and camera combinations are conceivable in such a system. However, there may also be systems in which the difference in image stabilization range is expected to be small depending on the interchangeable lens or the camera body. In this case, instead of acquiring the image stabilization ranges from the respective storage means and strictly acquiring the first division ratio, the final division ratio can be determined more easily than in the first embodiment by determining the first division ratio based on the expected approximate image stabilization range. For example, in the case of a system in which the operating ranges of the interchangeable lens 100a and the camera body 100b can be considered to be approximately equal, the first division ratio can be determined in advance as 1:1.

[0110] In this embodiment, information about image stabilization performance is acquired from the first storage means and the second storage means, but information about the image stabilization range is not acquired because the first division ratio has already been determined. The correction division setting unit 913 sets the fourth division ratio as the final division ratio, which is an increased ratio of the first optical image stabilization means, which has relatively higher image stabilization performance than the first division ratio. By doing so, it is possible to obtain the same effect as when operating with the third division ratio shown in the first embodiment. In other words, it is possible to ensure an image stabilization range according to the amount of image blur that is expected to occur during exposure, and to achieve control that makes use of image stabilization performance.

[0111] Furthermore, while interchangeable lens 100a can often accommodate the same amount of image blur regardless of focal length, camera body 100b generally accommodates a relatively smaller amount of image blur as the focal length increases. This is because the amount of image blur Δx is expressed as follows when the focal length is f and the amount of shake is Δθ:

[0112] Δx=f tan Δθ (Equation 3) As can be seen from equation 3, the longer the focal length, the greater the image blur that occurs on the imaging surface. On the other hand, the operating range of imaging surface image blur correction unit 117 provided in camera body 100b remains unchanged, so the range of shake that can be accommodated (Δθ) becomes a small value.

[0113] Therefore, these relationships may be stored in a table or the like and referenced for use. For example, at a focal length of 50 mm, the first division ratio between the interchangeable lens 100a and the camera body 100b is set to 1:2 (the camera body has more), and at a focal length of 100 mm, the first division ratio between the interchangeable lens 100a and the camera body 100b is set to 1:1 (the camera body and the lens have the same ratio). Furthermore, at a focal length of 200 mm, the first division ratio between the interchangeable lens 100a and the camera body 100b is set to 2:1 (the interchangeable lens has more). In this way, the first division ratio may be determined according to the focal length, and the correction division setting unit 913 may obtain from the storage means the first division ratio determined according to the focal length of the photographic optical system.

[0114] In this embodiment, a fourth ratio is obtained by increasing the ratio of the higher performance camera with reference to the image stabilization performance, and this is set as the final division ratio. In the above example, if camera body 100b has higher performance and a focal length of 100 mm, the ratio of camera body 100b can be increased from 1:1 to, for example, 1:2. As with the first embodiment, the extent to which the ratio should be changed can be determined taking into account the shooting conditions.

[0115] As described above, according to the third embodiment, when an imaging apparatus includes a plurality of image stabilization units, it is possible to provide an apparatus that can appropriately perform cooperative image blur correction with a simple configuration and achieve high image stabilization performance as a whole.

[0116] [Other embodiments] In the above-described embodiments, the configuration in which shake is detected using an angular velocity sensor has been described, but shake may be detected using other configurations. For example, a configuration in which the amount of shake is calculated from acceleration using an acceleration sensor, or the amount of shake of the device is calculated by detecting movement information from image data, may be employed.

[0117] Furthermore, in each of the above-described embodiments, the image stabilization unit provided in the interchangeable lens 100a is a lens-type image stabilization unit, but it is also possible to use an optical image stabilization unit that uses an optical element other than a lens, such as a prism.

[0118] In the first and second embodiments described above, there are shooting conditions in which the first division ratio and the second division ratio are set as the final division ratio. However, depending on the settable focal length and the size of the image stabilization range, the third division ratio may always be set.

[0119] 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.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions. [Explanation of symbols]

[0120] 100 Imaging device 100a interchangeable lens 100b camera body 105 Lens type image stabilization unit 110 Lens shake detection unit 111 Lens system control unit 112 Lens communication control unit 117 Image stabilizer unit 126 Camera system control unit

Claims

1. a first image blur correction means; an image blur correction control device that controls image blur correction by a second image blur correction unit that has lower image blur correction performance and a larger amount of remaining blur after image blur correction than the first image blur correction unit, a first acquisition means for acquiring a first division ratio; a division ratio determination means for determining a final division ratio based on the first division ratio; a control unit that controls the first image blur correction unit and the second image blur correction unit based on the final division ratio determined by the division ratio determination unit, The division ratio determination means an image blur correction control device capable of determining, as the final division ratio, a division ratio in which the ratio of the first image blur correction means is higher than the first division ratio;

2. 2. An image blur correction control device according to claim 1, wherein said first division ratio varies depending on the focal length of the photographing optical system.

3. The control means 3. The image blur correction control device according to claim 1, wherein the first image blur correction unit and the second image blur correction unit are controlled so that a ratio of the image blur correction amounts on the image plane between the first image blur correction unit and the second image blur correction unit becomes the final division ratio.

4. The first acquisition means acquiring information relating to a movable range of the first image blur correction means and information relating to a movable range of the second image blur correction means; 4. The image blur correction control device according to claim 1, wherein the first division ratio is determined based on information relating to a movable range of the first image blur correction means and information relating to a movable range of the second image blur correction means.

5. the first division ratio is predetermined and stored in a storage means, 4. The image stabilization control device according to claim 1, wherein the first acquisition means acquires the first division ratio by reading the first division ratio from the storage means.

6. a second acquisition unit that determines and acquires a second division ratio based on image blur correction performances of the first image blur correction unit and the second image blur correction unit, 6. The image blur correction control device according to claim 1, wherein the division ratio determination means determines the final division ratio based on the first division ratio and the second division ratio.

7. the first division ratio is a division ratio that maximizes an image blur correctable range by utilizing the first image blur correction unit and the second image blur correction unit, the second division ratio is a division ratio that maximizes the image stabilization performance, 7. The image blur correction control device according to claim 6, wherein the final division ratio is a ratio between the first division ratio and the second division ratio.

8. a photographing condition acquisition unit that acquires photographing conditions set in an image pickup apparatus that includes either the first image blur correction unit or the second image blur correction unit, 8. The image stabilization control device according to claim 1, wherein the division ratio determination means determines the final division ratio based on the photographing conditions acquired by the photographing condition acquisition means.

9. 9. The image stabilization control device according to claim 8, wherein the photographing conditions include at least one of an exposure time, a focal length of a photographing optical system, an imaging magnification of the photographing optical system, and a state of camera shake acting on the camera prior to the photographing.

10. 10. The image stabilization control device according to claim 8, wherein the division ratio determination means may determine the first division ratio as the final division ratio depending on the photographing conditions.

11. 11. The image blur correction control device according to claim 1, wherein the final division ratio indicates a gain.

12. 11. The image stabilization control device according to claim 1, wherein the final division ratio indicates a cutoff frequency.

13. An interchangeable lens that can be attached to an imaging device, an image blur correction control device according to any one of claims 1 to 12; a photographing optical system; an interchangeable lens, wherein the photographic optical system comprises an image blur correction unit that functions as either the first image blur correction unit or the second image blur correction unit;

14. An imaging device to which an interchangeable lens can be attached, an image blur correction control device according to any one of claims 1 to 12; an image pickup element that captures an image of light from the interchangeable lens; an actuator that moves the imaging element, an imaging surface image blur correction unit including the imaging element and the actuator, the imaging device functioning as either the first image blur correction unit or the second image blur correction unit;

15. a first image blur correction means; a second image blur correction unit having lower image blur correction performance and a larger amount of remaining blur after image blur correction than the first image blur correction unit, obtaining a first division ratio; determining a final division ratio based on the first division ratio; and controlling the first image blur correction unit and the second image blur correction unit based on the final division ratio. In the step of determining the final division ratio, a division ratio in which the ratio of the first image blur correction means is higher than the first division ratio, and the division ratio can be determined as the final division ratio;

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