JP5268546B2 - Optical apparatus and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suitably correct image shake due to camera shake in macro photographing irrespective of an exposure time. <P>SOLUTION: Optical equipment finds rotation radii respectively when regarding shift blur as angle shake, then, finds the rotation radii with less error by changing obtaining time of time series data for calculating the rotation radii in response to exposure time. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an anti-vibration system that corrects image blur to prevent deterioration of a captured image due to blur, and particularly relates to an optical apparatus having an image blur correction function that can perform good image blur correction even under shooting conditions with a large shooting magnification. Is.

  Blur applied to a photographing device such as a camera often causes image blurring and causes image degradation of the photographed image. In order to reduce the influence of the blur, there is an image blur correction technique for detecting a blur using an angular velocity meter and reducing an image blur on the image sensor surface by moving a part of the lens. The so-called angle blur that can be detected by this technology among the blurs applied to the photographing device has a great influence on most photographing conditions, so this technology is currently installed in various optical devices as an effective image blur correction function. .

  However, in close-up shooting (shooting conditions with a high shooting magnification), image degradation caused by so-called shift blur, which cannot be detected only by an angular velocity meter and is applied in a direction parallel or perpendicular to the optical axis of the camera, cannot be ignored. For example, in the case where the subject is photographed close to about 20 cm, or when the subject is located at about 1 m and the focal length of the photographing optical system is very large (for example, 400 mm), the shift blur is positively detected. It will be necessary to make corrections.

  In Patent Document 1, an accelerometer that detects the acceleration of the camera body is provided, shift blur is obtained from the second-order integration of the output of the accelerometer, angular blur is obtained from the integration of the angular velocity meter output provided separately, and blur correction is performed using these synthesized signals. There is disclosure to do. However, the output of the accelerometer is susceptible to environmental changes such as disturbance noise and temperature, particularly in the frequency range of camera shake. These instability factors are further expanded by second-order integration, and there is a problem that it is difficult to correct shift blur with high accuracy.

Patent Document 2 discloses that shift blur is obtained by regarding it as angle blur when the center of rotation is at a location away from the camera. In this method, an angular velocity meter and an accelerometer are provided, and the rotational radius and angle of angular blur are obtained from their outputs, and blur correction is performed. In this method, since the radius of rotation can be calculated from the output of the first-order integral of the output of the accelerometer, the instability factors of the accelerometer as described above can be reduced.
JP 7-225405 A JP 2005-114845 A

  In the method of obtaining shift blur using the rotational radius of angular blur, it is necessary to accurately determine the rotational radius. Although this turning radius may change with time, it is difficult to always calculate the turning radius in real time because of sensor performance.

  In view of the above problems, an object of the present invention is to realize an image stabilization system capable of performing a suitable blur correction even when a camera shaker temporally changes under a shooting condition with a high shooting magnification.

  In order to solve the above-mentioned problems, the present invention provides an optical apparatus having an image blur correction function as claimed in claim 1, an angular velocity detecting means for detecting an angular velocity of the optical apparatus, and an acceleration of the optical apparatus. Acceleration detecting means for detecting, correction amount determining means for determining a correction amount necessary for correcting the image blur, and blur correcting means for correcting the image blur based on the correction amount, The correction amount determining means acquires a rotation radius of blur applied to the optical device based on the time series data obtained from the angular velocity detecting means and the acceleration detecting means, and the data acquisition time of the time series data is the optical equipment The first data acquisition time corresponding to the first data acquisition time corresponding to the first exposure time and the second data acquisition time longer than the first exposure time. Than Characterized in that it comprises a long second data acquisition time.

  According to a fifth aspect of the present invention, there is provided an optical apparatus having an image blur correction function according to the fifth aspect, the angular velocity detecting means for detecting the angular velocity of the optical apparatus, and the acceleration detecting means for detecting the acceleration of the optical apparatus; , Correction amount determination means for determining a correction amount necessary to correct the image blur, and blur correction means for correcting the image blur based on the correction amount, the correction amount determination means, Based on the time-series data obtained from the angular velocity detection means and the acceleration detection means, a rotation radius of blur applied to the optical device is acquired, and the number of data acquisition times of the time-series data depends on the exposure time of the optical device. The first data acquisition number corresponding to the first exposure time and the second exposure time longer than the first exposure time are changed, and the first data acquisition number is larger than the first data acquisition number. 2 data collection Characterized in that it comprises a number.

According to a ninth aspect of the present invention, there is provided a control method for an optical device having an image blur correction function, wherein the angular velocity detecting step for detecting the angular velocity of the optical device and the acceleration for detecting the acceleration of the optical device are provided. Data acquisition for setting a time for acquiring time-series data of the angular velocity and the acceleration based on the determination in the detection step, the exposure time determination step for determining the exposure time information of the optical instrument, and the exposure time determination step group and time setting step, a rotation radius calculating step get the rotation radius of the blur applied to the optical device based on time-series data of said angular velocity and the acceleration which the acquired, the result obtained by the rotational radius calculation step Determining a correction amount necessary to correct image blur, and is set in the data acquisition time setting step. The data acquisition time is changed according to the exposure time of the optical device, and the first data acquisition time corresponding to the first exposure time and the second longer than the first exposure time. And a second data acquisition time longer than the first data acquisition time corresponding to the exposure time.

  According to a thirteenth aspect of the present invention, there is provided a control method for an optical device having an image blur correction function, the angular velocity detecting step for detecting the angular velocity of the optical device, and the acceleration for detecting the acceleration of the optical device. For the determination of the detection step, the exposure time determination step for determining the exposure time information of the optical device, the rotation radius calculation step for calculating the rotation radius of each timing of the blur applied to the optical device, and the exposure time determination step Based on the angular velocity and the acceleration, set the number of data acquisition of time series data, average the rotation radius by the number of data acquisition, the image blur based on the result obtained by the averaging step A determination step for determining a correction amount necessary for correction, and the data acquisition number is changed according to an exposure time of the optical instrument, A first data acquisition number corresponding to one exposure time and a second data acquisition corresponding to a second exposure time longer than the first exposure time and having a larger number than the first data acquisition number And a number.

  Under imaging conditions with a high imaging magnification, the data acquisition time or the number of data acquisitions of the time-series data used for obtaining the rotation radius is changed according to the exposure time. As a result, it is possible to realize an image stabilization system that can perform suitable blur correction even when the blur applied to the camera changes with time.

  An example of an optical apparatus having an image blur correction function that can be used in the present invention will be described. FIG. 1 is a plan view of a single-lens reflex camera, and FIG. 2 is a side view thereof. The anti-vibration system mounted on the interchangeable lens 101 mounted on the camera has a shake indicated by arrows 103p and 103y (hereinafter referred to as angle shake) and a shake indicated by arrows 104pa and 104ya (hereinafter referred to as shift shake) with respect to the optical axis 102. To compensate for blur.

  In the camera body 105, 105a is a release button, 105b is a mode dial (including a main switch), 105c is a retractable strobe, and 105d is a camera CPU. Reference numeral 106 denotes an image sensor, and 107p and 107y are angular velocity detection means (hereinafter referred to as angular velocity meters) for detecting angular blur around the arrows 103p and 103y, respectively. (Arrows 107pa and 107ya are the respective detection sensitivity directions.) Further, 104p and 104y are acceleration detection means (hereinafter referred to as accelerometers) for detecting shift blurs indicated by arrows 104pa and 104ya, respectively. Reference numeral 108 denotes a coil that performs blur correction by taking both angle blur and shift blur into account by driving the blur correction lens 108a freely in the directions of arrows 108p and 108y in FIGS.

  Here, the outputs of the angular velocity meters 107p and 107y and the accelerometers 104p and 104y are calculated by the lens CPU 109 to obtain a correction amount necessary for image blur correction. That is, in this embodiment, the lens CPU 109 functions as a correction amount determination unit. The actuator 110 drives the blur correction lens 108a via the coil 108 in accordance with the correction amount in synchronization with the half-press of the release button 104a (hereinafter, S1: an operation for instructing photometry and focusing for preparation for shooting). That is, in this embodiment, the actuator 110, the coil 108, and the shake correction lens 108a are used as shake correction means.

  Here, in the present embodiment, so-called optical image stabilization, in which the blur correction lens is moved in a plane perpendicular to the optical axis based on the calculated correction amount, is used as the blur correction unit. However, the correction method based on the correction amount is not limited to optical image stabilization, and may be a method as disclosed in Japanese Patent Laid-Open No. 2008-048013. That is, the object of the present invention can also be achieved by using electronic image stabilization that reduces the influence of blurring by changing the cut-out position of each shooting frame output by the image sensor, or by correcting with a combination thereof. . When electronic image stabilization is used, the camera shake correction unit is a camera CPU and an image sensor, and the combination of optical image stabilization and electronic image stabilization adds the camera CPU and image sensor to the configuration of this embodiment.

In this embodiment, the shift blur is obtained by regarding the angle blur when the center of rotation is at a location away from the camera. FIG. 3 is a diagram showing shift blur Y (104 pb) and angle blur θ (103 pb) applied to the camera. Although FIG. 3 shows only shift blur in the pitch direction, only the pitch direction will be described here because the yaw direction can be calculated in the same manner. The shift blur Y (104 pb) and angle blur θ (103 pb) at the principal point position of the photographing optical system, and the rotation radius L (301 p) when the blur rotation center O (302 p) is determined can be expressed by the following equations. . The rotation radius L (301p) is the distance from the rotation center O (302p) to the accelerometer 104p.
L = Y / tan θ (1)
L = V / tan ω (2)
Equation (1) calculates the rotation radius L (301) from the shift blur Y (104a) calculated by integrating the output of the accelerometer 104 twice and the angular blur θ (103b) obtained by integrating the output of the angular velocity meter 107 once. It is a formula. Equation (2) is an equation for obtaining the turning radius L (301) from the velocity V calculated by integrating the output of the accelerometer 104 once and the angular velocity ω that is the output of the angular velocity meter 107, and the equations (1), ( The radius of rotation L (301) can be obtained by any method of 2).

Here, since the blur angle and the angular velocity are small, the equations (1) and (2) can be approximated by the following equations.
L = Y / θ (3)
L = V / ω (4)
Equation (3) is the rotation radius L obtained from the displacement Y obtained by integrating the output of the accelerometer 104 twice and the angle θ obtained by integrating the output of the angular velocity meter 107 once. Equation (4) is obtained by calculating the rotation radius L from the velocity V obtained by integrating the output of the accelerometer 104 once and the angular velocity ω which is the output of the angular velocity meter 107. The equations (3) and ( The turning radius can be obtained by any method of 4).

Here, the blur δ occurring on the imaging surface of the imaging optical system will be described. Based on the shift blur Y at the principal point position of the photographing optical system, the angular blur θ of the photographing optical system, the focal length f of the photographing optical system, and the photographing magnification β, the blur δ generated on the imaging surface is obtained by the following equation (5).
δ = (1 + β) fθ + βY (5)
Here, the first term on the right side is the angle blur amount, and the second term on the right side is the shift blur amount. The focal length f and the imaging magnification β in the first term on the right side are obtained from the zoom and focus information of the imaging optical system, and the angle θ is obtained from the integration result of the angular velocity meter. Therefore, the block diagram of FIG. Thus, angle blur correction can be performed. In the second term on the right side, the shift blur amount can be obtained from the shift blur Y, which is the twice integrated value of the accelerometer, and the photographing magnification β obtained from the zoom and focus information.

However, in the present invention, the blur correction is performed on the blur δ that is rewritten from the formula (5) as the following formula (6).
δ = (1 + β) fθ + βLθ (6)
That is, with respect to shift blurring, instead of using shift blur displacement Y obtained by integrating the accelerometer output twice, the rotational radius L is obtained once by equation (4). The shift blur amount is calculated based on the rotation radius L, the angle blur θ, and the shooting magnification β obtained from the zoom and focus information.

  As described above, the rotation radius of blur may change with time, but it is difficult to obtain the rotation radius in real time and reflect it in the correction. Therefore, it becomes necessary to estimate the value of the turning radius that is dominant over the entire exposure time using data that can be acquired before correction. In this embodiment, the radius of rotation used for correction is calculated using a data group (time-series data) of angular velocity and acceleration obtained in a certain time region before correction.

  FIG. 4 is a diagram showing a temporal change in the rotation radius of the blur applied to the camera, where the vertical axis is the actual rotation radius of the blur and the horizontal axis is the time.

  t0 is an exposure start timing, and t1 and t2 are exposure end timings. t3 and t5 are timings at which the leading data of the time series data used for calculating the radius of rotation applied to one shooting starting at t0 is obtained, and t4 and t6 are the last data of the time series data. It is the timing obtained. That is, for example, in FIG. 4A, exposure is performed between t0 and t1, and a blur using the rotation radius between t4 and t1 is calculated using the rotation radius calculated from the data obtained between t3 and t4. Correction is applied. Here, the time period between t3 and t4 and the time period between t5 and t6 will be referred to as a data acquisition interval, and the time between each will be referred to as a data acquisition time.

  Arrows 401 to 404 indicate the average value of the rotation radius calculated from the time-series data in the setting conditions of each graph, and the hatched portions 405 to 408 indicate errors between the calculated average value of the rotation radius and the actual rotation radius. Show.

  When the exposure time is short (t0-t1) as shown in FIGS. 4A and 4C, the rotation radius in the vicinity of t0 is often dominant, and the rotation radius obtained in (a) with a short data acquisition time can be obtained. The error with respect to the actual turning radius is smaller. On the other hand, when the exposure time is long (t0-t2) as in (b) and (d), the rotation radius that is constantly applied to the camera for a long time is often dominant, and the data acquisition time is long (d ) Is smaller in error.

  The reason is considered as follows.

  The shakes that have a large effect on the camera can be roughly classified into the following two shakes. One is a high-frequency, small-amplitude blur having a center of rotation in the hand and arm that are relatively close to the camera. The other is a low frequency, large amplitude blur centered somewhere else in the entire body that is relatively far from the camera.

  When the exposure time is short, high-frequency blur has a greater effect than slowly changing low-frequency blur. On the other hand, when the exposure time is long, a low frequency blur having a large amplitude has a great influence.

  Therefore, in this embodiment, the length of the data acquisition time for calculating the radius of rotation is changed according to the exposure time. Specifically, for shooting with a long exposure time, a more suitable blur correction is realized by increasing the data acquisition time. An appropriate data acquisition section will be described later.

  Hereinafter, examples will be shown and described in detail.

  FIG. 5 is a block diagram of the image stabilization system in the present embodiment. This block diagram shows the configuration of blur (pitch direction) generated in the vertical direction of the camera, and a similar block is also provided for blur (yaw direction) generated in the horizontal direction of the camera. Since these two blocks basically have the same configuration, only the pitch direction will be described here.

  First, correction of angle blur will be described. The output of the angular velocity meter 107 is taken into the lens CPU 109. The output is input to a high-pass filter (hereinafter, HPF) 501 to cut the DC component. The output of the HPF 501 is integrated by an integration filter 502 and converted into an angle output θ. Note that these HPF and integral filter processing are obtained by calculating the output of the quantized angular velocity meter 107p in the lens CPU 109, and can be realized by a known difference equation or the like. In addition, it can be realized by an analog circuit using a capacitor or a resistor before being input to the lens CPU 109.

  Here, the cutoff frequencies of the HPF 501 and the integration filter 502 will be described. Since the frequency range of blurring is generally 1 Hz to 10 Hz, the cut-off frequency is a primary filter characteristic that cuts off frequency components of 0.1 Hz or less that are far from the frequency range of blurring. The output of the integration filter 502 is input to the sensitivity adjustment unit 504. The sensitivity adjustment unit 504 adjusts the output of the integration filter 502 based on the output of the zoom and focus information 503 input to the lens CPU 109 from a focus encoder or zoom encoder (not shown), and calculates a target value for angle blur correction. To do. The reason why the sensitivity adjustment unit 504 performs the adjustment is that the sensitivity of blur correction on the camera image plane with respect to the blur correction stroke of the coil 108 changes due to changes in the optical state of the lens such as zoom and focus.

  In this embodiment, the output of the sensitivity adjustment unit 504, which is a target value for angle blur correction, and the output of an output correction unit 511, which is a target value for shift blur correction, which will be described later, are added by the lens CPU 109, and the actuator 110 Is output.

  Next, the shift blur correction block will be described. The output of the angular velocity meter 107p is taken into the lens CPU 109. The output is input to the HPF 501 and the DC component is cut. The phase of the output of the HPF 501 is adjusted by the phase adjustment filter 505. Here, the phase adjustment by the phase adjustment filter 505 is to adjust the phase with the output of the integration filter 507 described later. Since the cutoff frequency of the integration filter 507 is 0.1 Hz, the phase adjustment filter 505 is also an HPF of 0.1 Hz.

  The output of the accelerometer 104p is input to the HPF 506, and the DC component is cut. The output of the HPF 506 is input to the integration filter 507 and converted into speed. At this time, the cutoff frequency of the HPF 506 is 0.1 Hz which is the same as that of the HPF 501, and the cutoff frequency of the integration filter 507 is 0.1 Hz which is the same as that of the phase adjustment filter 505 as described above. The integration filter 507 is constituted by a low-pass filter (hereinafter referred to as LPF). Further, since the phase adjustment filter 505 performs the HPF calculation by subtracting the LPF calculation result from the input, the phase of the integration filter 507 and the output are the same. The output of the integration filter 507 is input to the turning radius calculation means 508.

  The exposure time acquisition unit 509 outputs the acquired exposure time to the calculation change unit 510. The calculation change unit 510 outputs a signal designating a calculation method according to the exposure time to the turning radius calculation unit 508. The processing in the turning radius calculation means 508 will be described later.

  The output correction unit 511 calculates the shift blur amount Y from the angle θ output from the integral filter 502 and the rotation radius L output from the rotation radius calculation unit 508. Further, the shift blur amount Y is corrected based on the output of the zoom and focus information 503, and the correction amount is determined.

  The correction amount that is the output of the output correction unit 511 is added to the angle blur correction target value that is the output of the sensitivity adjustment unit 504, and is output from the lens CPU 109 as the final correction amount. The output of the lens CPU 109 is input to the coil 108 by the actuator 110, and the blur correction lens 108a is driven to perform the blur correction.

  A calculation method in the turning radius calculation means 508 will be described.

The turning radius calculation means 508 calculates the average value of the turning radii L obtained by Expression (4) in the angular velocity and acceleration data group (time series data) obtained within the data acquisition time. As data acquisition time described above, it is determined according to the exposure time T _V for more suitable correction. It is assumed that the first data acquisition time is set corresponding to the first exposure time, and the second data acquisition time is set corresponding to the second exposure time. At this time, if the second data acquisition time is longer than the first data acquisition time, the data acquisition time is set so that the second exposure time is longer than the first exposure time. Is done.

For example the exposure time _{T V} is a 25msec data acquisition time when it is less than the predetermined value _{T VC,} when the exposure time _{T V} is larger than the predetermined value _{T VC} is set to 100msec data acquisition time.

  The effect of the present invention can be obtained if the data acquisition interval is a time region before the exposure end timing.However, in consideration of applying the correction during the normal exposure time, in the time region before the exposure start timing. Preferably there is. Moreover, it is preferable that the timing for acquiring the last data in the time series data is near the timing of the start of exposure as the exposure time is shorter. On the other hand, when the exposure time is long, low-frequency blur is dominant as described above, and therefore good results can be expected without including data immediately before exposure. In consideration of this, the data acquisition section of the present embodiment can be set so that the timing of the center time of the section exists in a time region away from the exposure start timing when the exposure time is long. That is, it is assumed that the timing of the center time of the first data acquisition section corresponding to the first exposure time and the second data acquisition section corresponding to the second exposure time are set. At this time, if the timing of the center time of the second data acquisition section is farther from the exposure start timing than the timing of the center time of the first data acquisition section, the second exposure time is the first exposure time. It may be set so as to be longer than the exposure time.

  In this embodiment, regardless of the exposure time, the data obtained before the start of exposure and obtained at the timing closest to the exposure start timing is used as the last data.

  A flow of communication from the camera to the lens side including communication of data necessary for carrying out the present embodiment is shown in the flowchart of FIG.

  When an operation is performed on the camera 104 side, serial communication is performed to the lens via the CPU 104d in the camera 104, and the lens CPU 109 in the lens 101 performs serial communication processing. The serial communication process is performed by an interrupt process. Then, it is possible to determine the release button half-press, the release button full-press, exposure time (shutter speed), camera model, and the like by decoding the communication data.

  In step 100, an instruction (command) from the camera is analyzed, and the process branches to a process corresponding to each instruction.

  In step 101, since the focus drive command is received, in step 102, the speed of the focus lens drive motor is set according to the target drive pulse number, and focus lens drive is started.

  In Step 103, since the aperture drive command is received, in order to drive the aperture based on the transmitted aperture drive data, the drive pattern of the stepping motor is set in Step 104, and the set drive pattern is output to the stepping motor. Drive the aperture.

  In step 105, since the camera lens status communication is received, in step 106, the lens focal length information, camera shake correction operation state, etc. are transmitted to the camera, or the camera status state (release switch state, shooting mode, exposure). Time). The exposure time information from the camera 104 used in this embodiment is acquired by the exposure time acquisition means 509 in this step.

  In step 107, there are other instructions, such as lens focus sensitivity data communication and lens optical data communication, and those processes are also performed in step 108.

Next, processing performed by the lens CPU 109 for blur correction will be described with reference to the flowchart of FIG. Here, although only the pitch direction blur is shown, the yaw direction is the same. Blur correction is performed by timer interruption processing that occurs at regular intervals. In this embodiment, step 200 is an angular velocity detection step, step 201 is an acceleration detection step, and step 206 is a velocity acquisition step. Step 207 is an exposure time determination step, steps 208 and 209 are data acquisition time setting steps, step 210 is a turning radius calculation step, and step 216 is a determination step.
(Step 200) A signal obtained by A / D converting the signal of the angular velocity meter 107p is stored in a RAM area (not shown) set by VAD_DAT.
(Step 201) A signal obtained by A / D converting the signal of the accelerometer 104p is stored in a RAM area (not shown) set by ACCAD_DAT.
(Step 202) The signal VAD_DAT from the angular velocity meter 107p is inputted, and calculation is performed by the HPF 501.
(Step 203) Using the calculation result of step 202 as an input, the integration filter 502 performs an integration calculation. The result is stored in a RAM area (not shown) set by DEG_DAT. DEG_DAT is a shake angle displacement signal.
(Step 204) Using the calculation result of step 202 as an input, the phase adjustment filter 505 calculates the phase adjustment. This processing is performed in order to match the phase with the signal processing (HPF and integration) of the accelerometer 104p to be performed later.
(Step 205) The operation is performed by the HPF 506 with ACCAD_DAT as an input.
(Step 206) Using the calculation result of step 205 as an input, the integration filter 507 performs integration calculation. This calculation result is a signal representing the speed V of shift blur.
(Step 207) It is determined whether or not the exposure time T _V is equal to or less than a predetermined value T _VC . If T _VC follows the process proceeds to step _208, it is greater than _{T VC} proceeds to step 209.
(Step 208) the exposure time _{T V} is because it is less than the predetermined value _{T VC,} the data acquisition time of the time series data to 25 msec.
(Step 209) Since the exposure time T _V is greater than the predetermined value T _VC , the data acquisition time of the time series data is set to 100 msec.
(Step 210) From the calculation result of Step 204 and the calculation result of Step 206 (time-series data) within the data acquisition time, an average value of the rotation radius L obtained using Expression (4) is calculated. The obtained L is stored in a RAM area (not shown).
(Step 211) The following calculation is performed from the photographing magnification β calculated from the position of the zoom / focus 204, the focal length f, the blur angle displacement DEG_DAT calculated in Step 403, and the optical image stabilization sensitivity correction value α. Determine the correction amount. The calculation result is stored in a RAM area (not shown) set by SFTDRV.
α {(1 + β) × f × DEG_DAT + β × L × DEG_DAT}
(Step 212) A signal obtained by A / D converting the displacement signal of the vibration reduction lens is stored in a RAM area (not shown) set by SFTPST.
(Step 213) A feedback calculation (SFTDRV-SFTPST) is performed. The calculation result is stored in a RAM area (not shown) set by SFT_DT.
(Step 214) Multiply the loop gain LPG_DT by SFT_DT. The calculation result is stored in a RAM area (not shown) set by SFT_PWM.
(Step 215) A phase compensation calculation is performed to make a stable control system.
(Step 216) The calculation result of step 215 is output to the driver 104 as a blur correction drive signal.

As described above, in step 208 to step 210 in FIG. 7, when the exposure time _{T V} is less than or equal to the predetermined value _{T VC} is to shorten the data acquisition time to calculate the rotational radius _L, greater than _{T VC} is The rotation radius L is calculated by extending the data acquisition time. This makes it possible to perform a suitable shift blur correction in consideration of the exposure time.

The magnitude of the predetermined value T _VC and the data acquisition time corresponding thereto are not limited to those shown in this embodiment, and can be set as appropriate. Further, in this embodiment, two cases (whether or less than a predetermined value or larger) are shown as cases of exposure time. However, a method of performing case division of three or more and setting a data acquisition time according to each case. Is also possible. Further, a method of determining the data acquisition time by calculating the data acquisition time corresponding to the exposure time by calculation is also possible. In these cases, it is possible to perform a suitable blur correction reflecting the exposure time.

  The rotation radius may be calculated by averaging the values calculated for each moment with a certain period during the data acquisition time, or may be calculated from the amplitude within the data acquisition time.

  In this embodiment, the sampling period is always constant, and the change of the calculation formula of the rotation radius is defined by the number of data acquisition. That is, it is assumed that the first data acquisition number is set corresponding to the first exposure time, and the second data acquisition number is set corresponding to the second exposure time. At this time, if the second data acquisition number is larger than the first data acquisition number, the data acquisition is performed so that the second exposure time is longer than the first exposure time. The number is set.

  For simplification, the same components as those of the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only the characteristic part of the second embodiment will be described.

  The mechanical configuration and hardware configuration of the camera in this embodiment are exactly the same as those in the first embodiment.

FIG. 8 is a block diagram in the present embodiment. Differences from the first embodiment are as follows.
Comparing means 801 for calculating the turning radius at each moment based on the outputs of the integration filter 507 and the phase adjustment filter 505 is provided.
The processing of the turning radius calculation unit 508 in the second embodiment averages and calculates the turning radius according to the data acquisition number obtained from the calculation change unit 510.

For example, assuming that the output of the comparison unit 801 is L1, L2,... L10 in the order of new data, when the exposure time is short, the correction value obtained by the turning radius calculation unit 508 is expressed as follows.
L = (L1 + L2 + L3) / 3 (7)
When the exposure time is long, the correction value obtained by the rotation radius calculation means 508 is expressed as follows.
L = (L1 + L2 +... + L10) / 10 (8)
The blur correction interruption in the second embodiment will be described with reference to the flowchart of FIG. The operation steps of the main part are shown in steps 300 to 303, and other operations are denoted by the same step numbers as those in the first embodiment, and description thereof is omitted.

Step 300 is a rotation radius calculation step, step 301 is an exposure time determination step, and steps 302 and 303 are average steps.
(Step 300) The calculation result of step 204 and the calculation result of step 206 are compared to calculate the rotation radius L1, the rotation radius calculated in the previous blur correction interruption is L2, and the rotation radius calculated last time is L3. The data are sequentially stored in a RAM area (not shown).
(Step 301) the exposure time _{T V} it is determined whether it is less than the predetermined value _{T VC.} If T _VC follows the process proceeds to step _209, it is greater than _{T VC} proceeds to step 210.
(Step 302) Since the exposure time T _V is equal to or less than the predetermined value T _VC , the rotation radius L is calculated by setting the number of data acquisitions to 3.
L = (L1 + L2 + L3) / 3
(Step 303) Since the exposure time T _V is larger than the predetermined value T _VC , the rotation radius L is calculated by setting the data acquisition number to 10.
L = (L1 + L2 +... + L10) / 10

As described above, in step 300 to step 303 in FIG. 9, when the exposure time T _V is equal to or less than the predetermined value T _VC , the rotation radius L is calculated by reducing the number of data acquisition, and when the exposure time T _V is larger than T _VC. The rotation radius L is calculated by increasing the number of data acquisitions. This makes it possible to perform a suitable shift blur correction in consideration of the exposure time.

The magnitude of the value of the predetermined value _TVC and the number of data acquisition corresponding thereto are not limited to those shown in this embodiment, and can be set as appropriate. In the present embodiment, the method of dividing the exposure time into two cases (whether it is less than or equal to a predetermined value or larger) has been shown. However, three or more cases are divided, and the number of data acquisition is determined according to each case. Needless to say, it is possible to perform a suitable blur correction reflecting the exposure time.

  The present invention is not limited to an image stabilization system for a digital single-lens reflex camera or a digital compact camera, but can also be installed in a photographing apparatus such as a digital video camera or a mobile phone.

The top view of the camera carrying the anti-vibration system which can apply this invention. The side view of the camera carrying the anti-vibration system which can apply this invention. Explanatory drawing of the rotation center of blurring. Explanatory drawing of the setting of the data acquisition time with respect to exposure time, and its effect. 1 is a block diagram of Embodiment 1. FIG. The flowchart figure which shows the serial communication operation | movement by the side of an interchangeable lens. FIG. 3 is a flowchart of control according to the first embodiment. FIG. 3 is a block diagram of the second embodiment. FIG. 9 is a flowchart of control according to the second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Lens 102 Optical axis 103y Yaw direction angle shake 103p Pitch direction angle shake 104p Accelerometer 104pa Accelerometer detection direction 104pb Vertical detection direction 104y Accelerometer 104ya Accelerometer detection direction 104yb Lateral detection direction 105 Camera 105a Release switch 105b Mode dial 105c Retractable strobe 105d Camera CPU
105e Electronic finder 106 Image sensor 107p Angular velocity meter 107pa Detection direction of angular velocity meter 107y Angular velocity meter 107ya Detection direction of angular velocity meter 108 Coil 108a Blur correction lens 108y Blur correction lens drive direction 108p Blur correction lens drive direction 109 Lens CPU
110 Actuator

Claims (15)

An optical instrument having an image blur correction function,
Angular velocity detection means for detecting the angular velocity of the optical instrument;
Acceleration detecting means for detecting the acceleration of the optical device;
Correction amount determining means for determining a correction amount necessary for correcting the image blur;
Blur correction means for correcting the image blur based on the correction amount,
The correction amount determining means acquires a rotation radius of blur applied to the optical device based on time series data obtained from the angular velocity detecting means and the acceleration detecting means,
The data acquisition time of the time series data is changed according to the exposure time of the optical instrument, and a first data acquisition time corresponding to the first exposure time and a second longer than the first exposure time. An optical apparatus comprising: a second data acquisition time corresponding to an exposure time and longer than the first data acquisition time.   The optical apparatus according to claim 1, wherein the data acquisition section for acquiring the time series data is a time region before the exposure start timing of the optical apparatus.   The optical apparatus according to claim 2, wherein the time series data includes data immediately before the start of exposure.   In the data acquisition interval, the timing of the center of the data acquisition interval is changed according to the exposure time of the optical apparatus, and the timing of the center of the first data acquisition interval corresponding to the first exposure time is , Corresponding to a second exposure time longer than the first exposure time, the center timing is in a time region farther from the exposure start timing of the optical device than the first data acquisition interval, The optical apparatus according to claim 2, further comprising a second data acquisition section. An optical instrument having an image blur correction function,
Angular velocity detection means for detecting the angular velocity of the optical instrument;
Acceleration detecting means for detecting the acceleration of the optical device;
Correction amount determining means for determining a correction amount necessary for correcting the image blur;
Blur correction means for correcting the image blur based on the correction amount,
The correction amount determining means acquires a rotation radius of blur applied to the optical device based on time series data obtained from the angular velocity detecting means and the acceleration detecting means,
The data acquisition number of the time-series data is changed according to the exposure time of the optical instrument, and a first data acquisition number corresponding to the first exposure time and a second longer than the first exposure time. An optical apparatus comprising: a second data acquisition number that corresponds to an exposure time and is larger than the first data acquisition number.   6. The optical apparatus according to claim 5, wherein the time series data is data obtained at a constant sampling period.   The optical apparatus according to claim 5 or 6, wherein all of the time-series data is obtained in a time region before the exposure start timing of the optical apparatus.   The said correction amount determination means determines the speed of the said optical apparatus based on the said acceleration, and acquires the rotation radius of the said blur by the ratio of the said angular velocity and the said speed. Optical equipment. A method for controlling an optical apparatus having an image blur correction function,
An angular velocity detection step for detecting an angular velocity of the optical instrument;
An acceleration detecting step for detecting an acceleration of the optical device;
An exposure time determination step of determining information of an exposure time of the optical instrument;
A data acquisition time setting step for setting a time for acquiring time series data of the angular velocity and the acceleration based on the determination of the exposure time determination step;
A rotation radius calculating step get the rotation radius of the blur applied to the optical device based on time-series data of the acceleration and the obtained angular velocity,
Determining a correction amount necessary to correct image blur based on the result obtained by the rotation radius calculation step;
The data acquisition time set in the data acquisition time setting step is changed according to the exposure time of the optical instrument, the first data acquisition time corresponding to the first exposure time, and the first data acquisition time. And a second data acquisition time longer than the first data acquisition time corresponding to a second exposure time longer than the first exposure time.   The method of controlling an optical instrument according to claim 9, wherein the data acquisition time for acquiring the time series data is a time region before the exposure start timing of the optical instrument.   The method according to claim 10, wherein the time series data includes data immediately before the start of exposure.   In the data acquisition interval, the timing of the center of the data acquisition interval is changed according to the exposure time of the optical apparatus, and the timing of the center of the first data acquisition interval corresponding to the first exposure time is , Corresponding to a second exposure time longer than the first exposure time, the center timing is in a time region farther from the exposure start timing of the optical device than the first data acquisition interval, The optical data control method according to claim 9, further comprising a second data acquisition section. A method for controlling an optical apparatus having an image blur correction function,
An angular velocity detection step for detecting an angular velocity of the optical instrument;
An acceleration detecting step for detecting an acceleration of the optical device;
An exposure time determination step of determining information of an exposure time of the optical instrument;
A rotation radius calculating step for calculating a rotation radius of each timing of blur applied to the optical device;
Based on the determination of the exposure time determination step, setting the number of data acquisition of time series data from the angular velocity and the acceleration, an average step of averaging the turning radius by the number of data acquisition,
Determining a correction amount necessary for correcting image blur based on the result obtained by the averaging step, and
The data acquisition number is changed according to the exposure time of the optical apparatus, and corresponds to a first data acquisition number corresponding to the first exposure time and a second exposure time longer than the first exposure time. And a second data acquisition number that is larger than the first data acquisition number.   The method of controlling an optical instrument according to claim 13, wherein the time-series data is data obtained at a constant sampling period.   15. The method of controlling an optical instrument according to claim 13, wherein all of the time series data is obtained in a time domain before the exposure start timing of the optical instrument.

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