JP5121766B2 - Image blur correction apparatus, optical apparatus, image pickup apparatus, image blur correction apparatus control method, and program - Google Patents

Description

  The present invention relates to an imaging apparatus, a control method thereof, and a program, and more particularly to a shake correction technique in the imaging apparatus.

  In an imaging apparatus typified by a still camera or a video camera, there are an optical camera shake correction system, an image sensor shift type camera shake correction system, and the like as a system for correcting shake given to the apparatus from the outside. Hereinafter, a correction lens for performing optical camera shake correction will be referred to as a shift lens.

  In these methods, a shake correction amount is usually calculated by performing digital signal processing on a digital signal obtained by AD conversion of a signal from a sensor that detects the degree of shake. Then, the shift lens or the image sensor is driven by an analog signal obtained by DA-converting the processed digital signal.

  In general, a microcomputer is used as a device that performs AD conversion, digital signal processing, and DA conversion. The microcomputer also performs a filtering process for cutting off a signal in a predetermined frequency band.

  An angular velocity sensor is often used to detect the degree of shake. An angular velocity sensor vibrates a vibration material such as a piezoelectric element at a constant frequency, converts a force due to a Coriolis force generated by a rotational motion component into a voltage, and acquires angular velocity information. On the other hand, an ultra-compact and lightweight imaging device provided in a mobile phone or the like often detects a motion vector from a shift of an image captured from an imaging unit without using an angular velocity sensor.

  In the prior art, there is known one that changes the gain correction value of the shake detection means in accordance with the angle detected by the angular velocity sensor (see, for example, Patent Document 1). Also known is a technique that detects a motion vector from an image shift and changes the gain correction value of the shake detection means from the motion vector data (see, for example, Patent Document 2). According to these conventional techniques, the effect of the camera shake correction function can be enhanced by adjusting the gain correction value to an optimum value.

  As an example of the timing for changing the gain correction value, there is a timing at which the refractive index changes due to a change in the environment in which the imaging apparatus is placed. The change in the refractive index affects the sensitivity of the shift lens. Here, the sensitivity is a weighting constant necessary for correcting the shake for a predetermined amount of shake. Therefore, the gain correction value is given as the reciprocal of the sensitivity. Further, as a change in the refractive index due to a change in the environment in which the imaging device is placed, there is a case where the air enters the water from the air (or vice versa). For example, the absolute refractive index of air is about 1.0 and the absolute refractive index of water is about 1.3. Therefore, since the relative refractive index of water with respect to air is about 1.3, the gain correction value in water needs to be about 1.3 times the gain correction value in air.

Japanese Patent Laid-Open No. 3-134614 JP 2005-203861 A

  However, if the gain correction value is increased by a factor of 1.3 when it is detected that the image pickup device has entered the water, there is a problem that the shift lens or the image pickup device tends to stick to the drive limit end when there is a large shake. Further, when the imaging device enters the water, a large vibration is likely to occur due to the impact and the shaking of the water surface, so that the shift lens or the imaging device is more likely to stick to the drive limit end.

  On the other hand, when diving deeply in the water instead of near the surface of the water, there is no big shake like a shake near the surface of the water. Further, since the frequency band of camera shake shifts to the low frequency side due to the viscosity of water, there is a problem that the effect of correction is reduced.

  The present invention has been made in view of such circumstances, and provides a technique for suppressing the occurrence of a problem that the effect of camera shake correction is reduced when the imaging apparatus moves to an environment where the refractive index of light is different. The purpose is to do.

In order to solve the above problems, the present invention is the refractive index of an image stabilizer available under different environments, and detection means that issues detects the shake of the image blur correction device, the optical axis Performing correction means capable of correcting image blur due to deflection by deflection, filtering processing capable of changing a cutoff frequency with respect to a detection result of the detection means, and signal amplification processing for multiplying a predetermined amplification factor , Calculating means for calculating the correction amount of the correction means , driving means for driving the correction means based on the correction amount , and when moving from one environment to another environment having a higher refractive index than the environment , as well as changes based on the relative refractive index of the other environment for the certain circumstances the amplification factor in the signal amplification processing, having a changing means for changing a cut-off frequency in the filtering processing Providing image stabilizer, characterized in that.

  Other features of the present invention will become more apparent from the accompanying drawings and the following description of the preferred embodiments.

  With the above configuration, according to the present invention, it is possible to suppress the occurrence of a problem that the effect of camera shake correction is reduced when the imaging apparatus moves to an environment where the refractive index of light is different.

It is a block diagram which shows the structure of the imaging device of this invention. It is a block diagram which shows the internal structure of the shift lens drive control part 104 shown in FIG. It is a block diagram which shows the detailed structure of the image stabilization control part 211a and 211b shown in FIG. 5 is a flowchart showing a flow of an image stabilization process executed by a shift lens drive control unit 104. In addition to the interrupt control cycle for image stabilization processing, a main loop that is always executed repeatedly is shown. It is a flowchart which shows the detailed flow of the process in S503 of FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The individual embodiments described below will help to understand various concepts from the superordinate concept to the subordinate concept of the present invention. The technical scope of the present invention is determined by the scope of the claims, and is not limited by the following individual embodiments. In addition, all combinations of features described in the embodiments are not necessarily essential to the present invention.

  FIG. 1 is a block diagram showing the configuration of the imaging apparatus of the present invention. Although the image pickup apparatus of the present invention will be described with an optical camera shake correction method, an image pickup device shift type camera shake correction method that corrects shake by shifting the image pickup device instead of a shift lens in the optical camera shake correction method. Even so, the same effect can be obtained.

  In FIG. 1, reference numeral 101 denotes a zoom lens unit, which includes a zoom lens that performs zooming. Reference numeral 102 denotes a zoom lens drive control unit, which controls drive of the zoom lens unit 101. Reference numeral 103 denotes a shift lens as a shake correction optical system that can move in a direction substantially perpendicular to the optical axis. Reference numeral 104 denotes a shift lens drive control unit, which controls the drive of the shift lens 103. During operation in the power saving mode, power supply to the shift lens drive control unit 104 is stopped. Reference numeral 105 denotes an aperture / shutter unit. Reference numeral 106 denotes an aperture / shutter drive control unit, which controls drive of the aperture / shutter unit 105. Reference numeral 107 denotes a focus lens unit, which includes a lens that performs focus adjustment. Reference numeral 108 denotes a focus lens drive control unit, which controls drive of the focus lens unit 107. Reference numeral 109 denotes an image pickup unit including an image pickup device such as a CCD, which converts a light image that has passed through each lens group into an electric signal. Reference numeral 110 denotes an imaging signal processing unit that converts an electrical signal output from the imaging unit 109 into a video signal. A video signal processing unit 111 processes the video signal output from the imaging signal processing unit 110 according to the application.

  Reference numeral 112 denotes a display unit, which displays an image as necessary based on a signal output from the video signal processing unit 111. Reference numeral 113 denotes a display control unit that controls operations of the imaging unit 109 and the display unit 112. A shake detection unit 114 detects a shake given to the photographing apparatus and generates a signal indicating the degree of shake. Reference numeral 115 denotes a power supply unit that supplies power to each component of the imaging apparatus according to the application. An external input / output terminal unit 116 inputs / outputs communication signals and video signals to / from an external device. Reference numeral 117 denotes an operation unit for operating the imaging apparatus. Reference numeral 118 denotes a storage unit that stores various data such as video information. Reference numeral 119 denotes an audio unit that records sounds around the imaging apparatus. Reference numeral 120 denotes an external environment selection unit that can select the mode of the imaging apparatus in accordance with a user operation via the operation unit 117. In the following embodiments, an underwater mode corresponding to a mode for using the imaging device in water or a mode corresponding to a mode for using the imaging device in the air (in the atmosphere) can be selected. . Therefore, in the present embodiment, the user can select whether the imaging device is in water or in the air by using the external selection unit 120 via the operation unit 117. Alternatively, the external environment selection unit 120 may include a sensor that detects whether the imaging device is in water or in air, and may select the underwater mode or the in-air mode according to the detection result of the sensor. Reference numeral 121 denotes a control unit that controls the entire imaging apparatus.

  Next, the operation of the imaging apparatus having the above configuration will be described.

  The operation unit 117 includes a shutter release button configured such that the first switch (SW1) and the second switch (SW2) are sequentially turned on according to the amount of pressing. The first switch is turned on when the shutter release button is depressed approximately halfway, and the second switch is turned on when the shutter release button is depressed to the end. When the first switch of the operation unit 117 is turned on, the focus lens drive control unit 108 drives the focus lens unit 107 to perform focus adjustment, and the aperture / shutter unit drive control unit 106 drives the aperture / shutter unit 105. Set the appropriate exposure. Further, when the second switch is turned on, image data obtained from the light image exposed to the imaging unit 109 is stored in the storage unit 118.

  When an instruction to turn on the shake correction function is issued via the operation unit 117, the control unit 121 instructs the shift lens drive control unit 104 to perform a shake correction operation. The shift lens drive control unit 104 that has received the shake correction operation instruction performs the shake correction operation until an instruction to turn off the shake correction function is issued. When the operation unit 117 is not operated for a certain period of time, the control unit 121 cuts off the power supply to the display unit 112 for power saving. Further, in this imaging apparatus, one of the still image shooting mode and the moving image shooting mode can be selected by the operation unit 117, and the operation condition of each actuator control unit (such as the zoom lens drive control unit 102) in each mode. Can be changed. When an instruction to change the zoom by optical zoom is given to the operation unit 117, the zoom lens drive control unit 102 that has received the instruction via the control unit 121 drives the zoom lens unit 101 to indicate the designated zoom position. Move the zoom lens to. At the same time, based on the video signal output from the imaging unit 109 and processed by the imaging signal processing unit 110 and the video signal processing unit 111, the focus lens drive control unit 108 drives the focus lens unit 107 to perform focus adjustment.

  FIG. 2 is a block diagram showing an internal configuration of the shift lens drive control unit 104 shown in FIG. However, the shake detection unit 114 includes the vertical shake detection unit 114a and the horizontal shake detection unit 114b.

  The vertical direction shake detection unit 114a detects the vertical direction shake of the imaging apparatus in the normal posture. The horizontal shake detection unit 114b detects horizontal shake of the imaging apparatus in the normal posture. 211a and 211b are vertical and horizontal anti-vibration control units, which determine the target position of the shift lens 103 based on the vertical or horizontal shake correction amount, and control the position of the shift lens 103. Reference numerals 301a and 301b denote PID units for performing feedback control in the vertical and horizontal directions, respectively, and obtain a control amount based on the deviation between the target position and the actual position signal indicating the position of the shift lens 103, and position command signals Is output. Reference numerals 302a and 302b denote vertical and horizontal drive units, respectively, which drive the shift lens 103 based on a position command signal sent from the PID unit 301a or 301b. 303a and 303b are position detection units in the vertical direction and the horizontal direction, respectively, and detect the position of the shift lens 103 in each direction.

  Next, position control of the shift lens 103 by the shift lens drive control unit 104 will be described.

  In the position control of the shift lens 103, the drive units 302a and 302b drive the shift lens 103 in the respective directions based on signals representing the shake of the imaging device from the vertical shake detection unit 114a and the horizontal shake detection unit 114b. . A magnet is attached to the shift lens 103. The magnetic field of the magnet is detected by the position detection units 303a and 303b, and position signals indicating the actual position of the shift lens 103 are sent to the PID units 301a and 301b, respectively. The PID units 301a and 301b perform feedback control such that these position signals converge on the corrected position control signals sent from the image stabilization control units 211a and 211b, respectively. At this time, the PID units 301a and 301b perform PID control that selectively combines proportional control, integral control, and differential control. As a result, image shake can be suppressed even if shake such as camera shake occurs in the imaging apparatus.

  FIG. 3 is a block diagram illustrating a detailed configuration of the image stabilization controllers 211a and 211b illustrated in FIG. The image stabilization control units 211a and 211b control the shakes in different directions, but the basic configuration is the same, and therefore, the image stabilization control unit 211 will be described simply as the image stabilization control unit 211 in FIG.

  Reference numeral 201 denotes an AD conversion unit that converts analog data, which is shake information detected by the shake detection unit 114, into digital data. A digital high-pass filter 202 is a filter that passes a predetermined (variable) high frequency band (performs a high frequency band pass process). A gain correction value changing unit 203 determines a gain correction value based on information (for example, the underwater mode or the in-air mode) selected by the outside world selection unit 120. A gain correction value multiplication unit 204 multiplies the digital data (shake information) output from the digital high-pass filter 202 by the gain correction value determined by the gain correction value change unit. Reference numeral 205 denotes a digital low-pass filter. When the data detected by the shake detection unit 114 indicates the angular velocity, and the shift lens drive control unit 104 controls the drive of the shift lens 103 based on the angle, the digital low-pass filter 205 operates as an integrator.

  A shake correction amount calculation unit 206 performs sign inversion on the angle signal (shake amount) output from the digital low-pass filter 205. Then, a shake correction amount reflecting the zoom position information from the zoom lens drive control unit 102 and the focus information from the focus lens drive control unit 108 is calculated. Further, the cut-off frequency changing unit 208 is notified of the calculation result so that the cut-off frequency changing unit 208 can refer to it when adjusting the cut-off frequency. Reference numeral 207 denotes a shake correction amount limiting unit, which sets and limits an upper limit value for the shake correction amount in order to drive the shift lens 103 while keeping the optical performance of the shift lens 103 within an allowable range. A cutoff frequency changing unit 208 changes the cutoff frequency of the digital high-pass filter 202 and the digital low-pass filter 205 based on information selected by the external selection unit 120. Reference numeral 209 denotes a shake correction amount limit value changing unit that changes the limit value of the shake correction amount limit unit 207 based on the information selected by the external selection unit 120.

  FIG. 4 is a flowchart showing the flow of the image stabilization process executed by the shift lens drive control unit 104. This anti-vibration processing is repeatedly executed at certain control cycles by interruption processing.

  FIG. 5 shows a main loop that is always repeatedly executed independently of the interrupt control cycle for the image stabilization process. As will be described later, by incrementing the counter during the image stabilization process, each process is executed in a cycle that is an integral multiple of the interrupt control cycle.

  In S401, the shift lens drive control unit 104 increments the values of the counter a, the counter b, and the counter c that are used in the main loop, respectively. In S402, the AD conversion unit 201 (see FIG. 3) performs AD conversion on the shake signal from the shake detection unit 114. In step S403, the digital high-pass filter 202 performs high-pass filter processing (HPF processing) on the shake signal to remove the offset. In step S405, the gain correction value multiplication unit 204 multiplies the gain correction value by the output of the HPF process. The gain correction value is a value determined by the gain correction value changing unit 203 in S605 and S612 of FIG. In step S406, the digital low-pass filter 205 performs a low-pass filter (LPF) process on the output of the gain correction process. Thereby, the angular velocity signal detected by the shake detection unit 114 is converted into an angle signal. In step S <b> 407, the shake correction amount calculation unit 206 performs sign inversion on the output of the LPF process, and performs processing that reflects the zoom magnification and focus information. Also, the shake correction amount limiting unit 207 limits the value of the output signal as necessary. In step S <b> 408, the PID unit 301 performs PID control based on the output signal from the shake correction amount limiting unit 207 and the position signal from the position detection unit 303. In step S409, the PID unit 301 drives the shift lens 103 by issuing a drive command to the drive unit 302.

  Next, the main loop of FIG. 5 will be described. In S501, the shift lens drive control unit 104 determines whether the counter a is equal to or greater than a predetermined value Ta. If the counter a is equal to or greater than Ta, the process proceeds to S504, and if not, the process proceeds to S02. This means that S502 and S503 are executed in a cycle that is Ta times the control cycle described in FIG. In S502, the shift lens drive control unit 104 clears the counter a. In S503, the shift lens drive control unit 104 performs underwater processing (described later with reference to FIG. 6). Similarly, in S504 and S507, it is determined whether or not the counter b and the counter c are equal to or greater than Tb and Tc, respectively. If the determination result is “Yes”, S505 to S506 and S508 to S510 are executed. . In S506, pan control is executed, and in S509 and S510, transmission / reception monitoring processing is executed. However, when the CPU that executes the image stabilization control (that is, the CPU included in the shift lens drive control unit 104) is integrated with the CPU of the control unit 121 that controls the entire imaging apparatus, the processing of S507 to S510 is performed. Is not necessarily required.

  FIG. 6 is a flowchart showing a detailed flow of the process in S503 of FIG.

  In step S <b> 601, the shift lens drive control unit 104 determines whether the imaging device is in the underwater mode or the in-air mode based on the information selected by the external environment selection unit 120. As described above, the external environment selection unit 120 may select the underwater mode or the in-air mode according to a user operation (for example, selection of a button corresponding to “underwater”) via the operation unit 117, or the imaging apparatus A sensor that detects whether the vehicle is in water or in air may be used, and the underwater mode or the air mode may be selected according to the detection result of the sensor. In the case of the underwater mode, the process proceeds to S602, and in the case of the in-air mode, the process proceeds to S611. In S602, the gain correction value changing unit 203 determines whether or not the current gain correction value of the gain correction value multiplying unit 204 is a value corresponding to the underwater mode. The gain correction value corresponding to each mode at this time is the relative refractive index of water and air as in the conventional case. For example, the absolute refractive index of air is about 1.0, and the absolute refractive index of water is about 1.3. Therefore, since the relative refractive index of water with respect to air is about 1.3, the gain correction value in water needs to be about 1.3 times the gain correction value in air. If it is a gain correction value corresponding to the underwater mode, the process proceeds to S606, and if it is not a gain correction value corresponding to the underwater mode, the process proceeds to S603. The fact that the gain correction value does not correspond to the underwater mode in S602 means that the selection by the external selection unit 120 has changed from the in-air mode to the underwater mode at this timing.

  In step S <b> 603, the cutoff frequency changing unit 208 increases the cutoff frequencies of the digital high pass filter 202 and the digital low pass filter 205. When the cut-off frequency of the digital high-pass filter 202 is increased, correction for low-frequency shake is not performed, so that the shift lens 103 is suppressed from sticking to the drive limit end. When the cut-off frequency of the digital low-pass filter 205 is increased, the value of the angle signal output from the digital low-pass filter 205 is reduced, so that the shift lens 103 is prevented from sticking to the drive limit end. Accordingly, the cutoff frequency changing unit 208 may increase the cutoff frequency of only one of the digital high-pass filter 202 and the digital low-pass filter 205.

  In step S <b> 604, the shake correction amount limit value changing unit 209 increases the limit value of the shake correction amount limit unit 207. As a result, the range in which the shift lens 103 can move is widened, so that the shift lens 103 is prevented from sticking to the drive limit end. In S605, the gain correction value changing unit 203 multiplies the gain correction value of the gain correction value multiplication unit 204 by 1.3 (that is, increases the gain correction value). In step S606, the cutoff frequency changing unit 208 determines whether or not the shake correction amount output from the shake correction amount calculation unit 206 is equal to or less than a predetermined value. The predetermined value is set as a shake correction amount that does not increase the possibility that the shift lens 103 sticks to the drive limit end. If the shake correction amount is equal to or less than the predetermined value, there is no large shake and the possibility that the shift lens 103 sticks to the drive limit end is low, and the process proceeds to S607. Otherwise, the shift lens 103 is likely to stick to the drive limit end, and the process proceeds to S609.

  In step S <b> 607, the cutoff frequency changing unit 208 determines whether the cutoff frequencies of the digital high-pass filter 202 and the digital low-pass filter 205 have reached a predetermined lower limit value. If the lower limit value has not been reached, the cutoff frequency changing unit 208 further lowers the cutoff frequencies of the digital high-pass filter 202 and the digital low-pass filter 205 (or one of them) in S608. If there is no significant shaking in the water, the processing in S608 is repeated every Ta cycle, and the low-frequency-side correction suitable for underwater photography is approached. Therefore, the problem that “the effect of correction is reduced because the frequency band of camera shake shifts to the low frequency side due to the viscosity of water” is reduced. On the other hand, in S609, the cutoff frequency changing unit 208 determines whether the cutoff frequencies of the digital high-pass filter 202 and the digital low-pass filter 205 have reached the upper limit values. If the upper limit value has not been reached, the cutoff frequency changing unit 208 further increases the cutoff frequencies of the digital high-pass filter 202 and the digital low-pass filter 205 (or one of them) in S610. Thereby, the possibility that the shift lens 103 sticks to the drive limit end is reduced.

  If it is determined in S601 that the mode is not underwater mode, the gain correction value changing unit 203 determines in S611 whether the current gain correction value of the gain correction value multiplication unit 204 is a value in the in-air mode. If it is a value in the air mode, the process proceeds to S614, and if not, the process proceeds to S612. In step S612, the gain correction value changing unit 203 decreases the gain correction value of the gain correction value multiplication unit 204 and sets the gain correction value in the in-air mode. In step S613, the shake correction amount limit value changing unit 209 decreases the limit value of the shake correction amount limit unit 207 and sets the limit value in the in-air mode. In step S614, the cutoff frequency changing unit 208 determines whether the cutoff frequencies of the digital high-pass filter 202 and the digital low-pass filter 205 are cutoff frequencies in the air mode. If the determination result is “No”, in S615, the cutoff frequency changing unit 208 brings the cutoff frequencies of the digital high-pass filter 202 and the digital low-pass filter 205 close to the cutoff frequency in the air mode. If the imaging device is in the air, the process of S615 is repeated every Ta cycle, so that the cutoff frequencies of the digital high-pass filter 202 and the digital low-pass filter 205 gradually return to the cutoff frequency in the air mode.

  As described above, according to this embodiment, when the imaging apparatus enters the water, the gain correction value of the gain correction value multiplication unit 204 of the shift lens drive control unit 104 is changed to a value corresponding to the underwater mode. Further, the cutoff frequency of the digital high-pass filter 202 and the digital low-pass filter 205 (or one of them) is increased. Thereafter, if the shake of the imaging device is small, the cutoff frequency is gradually lowered. Accordingly, it is possible to suppress the occurrence of a problem that the effect of camera shake correction is reduced when the imaging apparatus moves to an environment where the refractive index of light is different.

[Other Examples]
In order to realize the functions of the above-described embodiments, a recording medium in which a program code of software embodying each function is recorded may be provided to the system or apparatus. Then, the function of each embodiment described above is realized by the computer (or CPU or MPU) of the system or apparatus reading and executing the program code stored in the recording medium. In this case, the program code itself read from the recording medium realizes the functions of the above-described embodiments, and the recording medium on which the program code is recorded constitutes the present invention. As a recording medium for supplying such a program code, for example, a floppy (registered trademark) disk, a hard disk, an optical disk, a magneto-optical disk, or the like can be used. Alternatively, a CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like can be used.

  The configuration for realizing the functions of the above-described embodiments is not limited to executing the program code read by the computer. Including the case where the OS (operating system) running on the computer performs part or all of the actual processing based on the instruction of the program code, and the functions of the above-described embodiments are realized by the processing. It is. Further, the program code read from the recording medium may be written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, the CPU of the function expansion board or function expansion unit performs part or all of the actual processing based on the instruction of the program code, and the functions of the above-described embodiments may be realized by the processing. Is included.

Claims (11)

An image blur correction apparatus that can be used in a plurality of environments having different refractive indexes ,
A detecting unit that issues detects the shake of the image blur correction device,
Correction means capable of correcting image blur due to the shake by deflecting the optical axis;
Calculating means for calculating a correction amount of the correction means by performing a filtering process capable of changing a cutoff frequency on a detection result of the detection means and a signal amplification process of multiplying a predetermined amplification factor ;
Drive means for driving the correction means based on the correction amount ;
When changing from one environment to another environment having a higher refractive index than the environment, the gain in the signal amplification process is changed based on the relative refractive index of the other environment with respect to the environment, image stabilizer and having a changing means for changing a cut-off frequency in the filtering process. The changing means changes the cut-off frequency in the filtering process so that the correction for the low frequency component of the shake is not performed before the increase of the gain when the gain is increased. The image blur correction device according to claim 1. The changing means, after correction for the low frequency component of the shake has changed the cutoff frequency in the filtering process so as not performed, that the amount of correction further modified lower the cut-off frequency the smaller The image blur correction device according to claim 2 , wherein Further comprising a limiting means to limit the magnitude of the correction amount to a predetermined limit value,
Before SL change means, said when the amplification factor is increased, the image blur correction apparatus according to claim 1 or 3, characterized in that changing to increase the predetermined limit value. The image blur correction device can be used in air and water as a plurality of environments having different refractive indexes , and sets the amplification factor corresponding to photographing when the image blur correction device is in water. underwater mode, the air mode in which the image blur correction device sets the amplification factor in response to shooting when in air, a selection means for selecting one of the at least two modes, including Have
Image blur correction apparatus described before Symbol change means to any one of claims 1 to 4, characterized in that to change the amplification factor in response to the selection of said selection means. When changing from the air mode to the underwater mode by the selection means, the change means changes the cutoff frequency in the filtering process so that correction for the low frequency component of the shake is not performed. 6. The image blur correction device according to claim 5, wherein When changing from the water mode to the air mode by said selection means, said changing means, said when the amplification factor is decreased, and changes to reduce the predetermined limit value, wherein The image blur correction device according to claim 5 subordinate to claim 4 or claim 6 subordinate to claim 4 .   An optical apparatus comprising the image blur correction device according to claim 1.   An imaging device comprising the image blur correction device according to claim 1. A control method of an image blur correction apparatus that includes a correction unit that can correct image blur due to shake by deflecting an optical axis, and that can be used in a plurality of environments having different refractive indexes ,
A detecting step that detection means of the image blur correction apparatus, issues detects the shake of the image blur correction device,
The calculation unit of the image blur correction apparatus performs a filtering process that can change a cutoff frequency on the detection result of the detection step, and a signal amplification process that multiplies a predetermined amplification factor, and a correction amount of the correction unit A calculation step of calculating
A driving step of driving the correction unit based on the correction amount , the driving unit of the image blur correction device ;
When the changing means of the image blur correction apparatus moves from one environment to another environment having a refractive index larger than that of the environment, the amplification factor in the signal amplification process is changed from that of the other environment to the environment. with changes based on the relative refractive index, the control method of the image blur correction apparatus; and a changing step of changing a cutoff frequency in the filtering process. The program for making a computer perform each process of the control method of the image blurring correction apparatus of Claim 10 .

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