JP6268981B2 - Blur correction device, interchangeable lens and camera - Google Patents

Description

The present invention relates to a shake correction device, an interchangeable lens, and a camera.

There is a technique for performing optical camera shake correction based on a signal from an angular velocity sensor (gyro). In this technique, it is necessary to accurately obtain the reference value (gyro output value at 0 deg / s) of the angular velocity sensor, but the reference value of the angular velocity sensor changes depending on drift characteristics immediately after startup, temperature characteristics, and the like. It is difficult to find accurately.
Therefore, a technique has been proposed in which the output signal of the angular velocity sensor is calculated by LPF (low-pass filter) processing and further corrected using motion vector information.
In addition, center bias processing is sometimes performed to prevent the blur correction lens from reaching the movable end, but a technique for changing the correction gain of the angular velocity reference value according to the amount of the center bias has also been proposed. (See Patent Document 1).

Japanese Patent No. 4360147

However, as described above, a technique for correcting the angular velocity reference value by using motion vector information has been proposed, but has the following problems.
The blur on the imaging surface detected as a motion vector includes an error component of a reference value and a center bias component. However, in the prior art, since the reference value is corrected using the motion vector information including the center bias component, accurate reference value correction cannot be performed.
Further, since the influence of the reference value error amount on the imaging surface differs depending on the focal length, there is a problem that the reference value correction cannot be performed accurately depending on the focal length. For example, when the focal length is short, the influence of the reference value error on the imaging surface is small, and it cannot be detected as a motion vector unless the reference value error is provided to some extent.
Furthermore, even when the motion vector detection resolution changes (such as when the interchangeable lens body changes), the detection accuracy of the reference value error component changes, so that it may not be accurately detected depending on the detection resolution.
An object of the present invention is to provide a shake correction device, an interchangeable lens, and a camera capable of correcting a reference value with high accuracy.

According to a first aspect of the present invention, there is provided a drivable blur correction element that corrects a blur of a subject image formed by an optical system, an angular velocity sensor that detects an angular velocity of an optical device including the optical system, and the angular velocity sensor. A reference value calculation unit for calculating a reference value of the output signal of the output signal, and information on a motion vector calculated from the subject image formed by the optical system, and in advance according to the motion vector and the focal length of the optical system Based on the reference value correction unit that corrects the reference value by a reference value correction value calculated by a determined correction amount, and the output signal of the angular velocity sensor and the corrected reference value, the blur correction is performed. And a target position calculation unit that calculates a target position of the element.
The invention according to claim 2 is the blur correction device according to claim 1, wherein the correction amount when the focal length of the optical system is f1 is f2 in which the focal length of the optical system is longer than f1. This is a shake correction device larger than the correction amount in the case of.
A third aspect of the present invention is the blur correction device according to the first or second aspect, wherein the reference value correcting unit is configured to use the reference value when the focal length of the optical system is equal to or less than a first threshold value. This is a shake correction device that does not correct the image.
A fourth aspect of the present invention is the blur correction apparatus according to any one of the first to third aspects, wherein the reference value correction value is a blur that changes according to a detection resolution of the motion vector. It is a correction device.
According to a fifth aspect of the present invention, in the blur correction device according to any one of the first to fourth aspects, the reference value correction unit has a second difference between the motion vectors of different frames. The blur correction device corrects the reference value when it is larger than a threshold value.
The invention according to claim 6 is the shake correction apparatus according to claim 5, wherein the second threshold when the focal length of the optical system is f1 is longer than the focal length of the optical system. The blur correction device is smaller than the second threshold value in the case of f2.
According to a seventh aspect of the present invention, there is provided a drivable blur correction element that corrects a blur of a subject image formed by an optical system, an angular velocity sensor that detects an angular velocity of an optical device including the optical system, and the angular velocity sensor. A reference value calculation unit for calculating a reference value of the output signal of the output signal, and correcting the reference value using a motion vector calculated from a plurality of the subject images, and setting a correction amount for correcting the reference value as a resolution for detecting the motion vector And a target position calculator that calculates a target position of the blur correction element based on the output signal of the angular velocity sensor and the corrected reference value. Device.
The invention according to claim 8 is the shake correction apparatus according to claim 7, wherein the correction amount of the reference value whose detection resolution of the motion vector is d1 is d2, which has a resolution higher than d1. The shake correction device is larger than the correction amount of the reference value.
The invention according to claim 9 is the shake correction apparatus according to claim 6 or 7, wherein the reference value correction unit corrects the reference value when the detection resolution is lower than a third threshold value. There is no blur correction device.
A tenth aspect of the present invention is an interchangeable lens that is detachably attached to a camera body, comprising the blur correction device according to any one of the first to ninth aspects, wherein the blur correction element is provided. Is an interchangeable lens which is at least a part of the optical system and is a drivable blur correction optical system that corrects blur of the subject image.
An eleventh aspect of the present invention is the blur correction device according to any one of the first to ninth aspects, wherein the blur correction element captures the subject image formed by the optical system. This is a shake correction device that is an imaging device.
A twelfth aspect of the present invention is a camera including the shake correction apparatus according to any one of the first to eleventh aspects.

  According to the present invention, it is possible to provide a shake correction apparatus, a lens barrel, and a camera that are capable of correcting a reference value with high accuracy.

It is sectional drawing which shows typically a camera provided with the blurring correction apparatus of 1st Embodiment. It is a block diagram of the blurring correction apparatus of 1st Embodiment. It is the flowchart which showed the flow of operation | movement of the blurring correction apparatus of 1st Embodiment. It is a figure explaining the reference value calculating part in 1st Embodiment, (a) is a reference value calculating part, (b) is the figure which showed LPF of the reference value calculating part. It is a flowchart which shows the reference value correction | amendment calculation in 1st Embodiment. 5 is a graph showing a relationship between a focal length and a reference value correction amount in the first embodiment. FIG. 10 is a graph showing difference data of a motion vector 2 (after removal of the center bias component) from one frame before in the second embodiment, where (a) shows tele, and (b) shows wide. It is the graph which showed the relationship between a focal distance and a reference value correction threshold value in 2nd Embodiment. It is a block diagram of the blurring correction apparatus of 3rd Embodiment. It is the figure which showed the relationship between the motion vector detection resolution and reference value correction amount in 3rd Embodiment. It is the figure which showed the relationship between the motion vector detection resolution and a reference value correction threshold value in 3rd Embodiment. It is a block diagram of the blurring correction apparatus of 4th Embodiment. It is the graph which showed the relationship between a focal distance, resolution | decomposability, and a reference value correction amount in 4th Embodiment. It is the graph which showed the relationship between a focal distance, resolution | decomposability, and a threshold value in 4th Embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings and the like.
FIG. 1 is a cross-sectional view schematically showing a camera 1 including the shake correction apparatus of the first embodiment.
The camera 1 is a digital single-lens reflex camera, and includes a camera housing 1A and a lens barrel (optical member) 1B that is detachably attached to the camera housing 1A.

  The camera housing 1A includes a camera CPU 2A, an image sensor 3, a recording medium 13, an EEPROM 14, a signal processing circuit 15, an AF sensor 16, a release switch 17, a rear liquid crystal 18, a mirror 19, a sub mirror 19a, and a shutter 20.

The camera CPU 2A is a central processing unit that performs overall control of the camera 1, and constitutes a part of the shake correction device of the present embodiment.
The imaging element 3 is an element that captures a subject image formed by the photographing lenses (4, 5, 6), exposes the subject light to convert it into an electrical image signal, and outputs it to the signal processing circuit 15. The image pickup device 3 is configured by an element such as a CCD or a CMOS.

The recording medium 13 is a medium for recording captured image data, and an SD card, a CF card, or the like is used.
The EEPROM 14 is a memory that stores adjustment value information such as the gain value of the angular velocity sensor 12, information unique to the lens barrel, and the like, and outputs the memory to the CPU 2.
The signal processing circuit 15 is a circuit that receives an output from the image sensor 3 and performs processing such as noise processing and A / D conversion.

The AF sensor 16 is a sensor for performing AF (automatic focus adjustment), and a CCD or the like can be used.
The release switch 17 is a member that performs a photographing operation of the camera 1 and is a switch that operates a shutter driving timing and the like.

  The rear liquid crystal 18 is provided on the rear surface of the camera housing 1A of the camera 1 and displays a subject image (reproduced image, live view image) photographed by the image sensor 3 and information (menu) related to operation. It is.

  The shutter 20 is disposed behind the mirror 19. Subject light is incident on the shutter 20 when the mirror 19 rotates upward and becomes ready for photographing. The shutter 20 travels through a shutter curtain in response to a shooting instruction from the release switch 17 or the like, and controls subject light incident on the image sensor 3. A sub-mirror 19 a is provided behind the mirror 19 and guides subject light to the AF sensor 16.

  The lens barrel 1B includes a zoom lens group 4, a focus lens group 5, a shake correction lens group (optical element) 6, a zoom lens group drive mechanism 7, a focus lens group drive mechanism 8, and a shake correction lens group drive mechanism (optical element drive). Part) 9, a diaphragm 10, a diaphragm drive mechanism 11, an angular velocity sensor 12, and a lens CPU 2B.

  The lens CPU 2B calculates the movement amount of the lens groups such as the zoom lens group 4, the focus lens group 5, and the blur correction lens group 6. The zoom lens group drive mechanism 7, the focus lens group drive mechanism 8, the blur correction lens group drive mechanism 9 and the aperture drive mechanism 11 are instructed to move the zoom lens group 4, the focus lens group 5, and the blur correction lens group 6. Move.

The zoom lens group 4 is a lens group that is driven by the zoom lens group drive mechanism 7 and moves along the optical axis direction to continuously change the magnification of the image.
The focus lens group 5 is a lens group that is driven by the focus lens group drive mechanism 8 and moves in the optical axis direction to focus.
The shake correction lens group 6 (optical element) is a lens group that is optically shake-corrected and driven on a plane perpendicular to the optical axis by a shake correction lens group drive mechanism 9 such as a VCM.

The diaphragm 10 is a mechanism that is driven by the diaphragm drive mechanism 11 and controls the amount of subject light passing through the photographing lenses (4, 5, 6).
The angular velocity sensor 12 is a sensor that detects an angular velocity of a shake that occurs in each sensor unit.

FIG. 2 is a block diagram of the shake correction apparatus 100 of the present embodiment.
The shake correction apparatus 100 includes a camera CPU 2A, a lens CPU 2B, an angular velocity sensor 12, a shake correction lens group drive mechanism (lens drive unit) 9, a lens position detection unit 21, and a shake correction lens group 6.

The camera CPU 2 </ b> A includes an image sensor 3, a signal processing unit 40, and a motion vector calculation unit 41.
The lens CPU 2B includes an amplification unit 31, a first A / D conversion unit 32, a second A / D conversion unit 33, a reference value calculation unit 34, a reference value correction amount calculation unit 35, and a target position calculation unit 36 including an integration unit therein. A center bias calculator 37, a center bias remover 38, and a drive amount calculator 39.
The angular velocity sensor 12 includes a lens barrel 1B around the X axis (Pitch), around the Y axis (Yaw) (where the X axis is the horizontal axis of the light receiving surface of the image sensor 3 at the normal position of the camera, and the Y axis is This is a sensor such as a vibration gyro that detects the angular velocity of the vertical axis.

The amplifying unit 31 amplifies the output of the angular velocity sensor 12.
The first A / D converter 32 performs A / D conversion on the output of the amplifier 31.
The reference value calculation unit 34 calculates a reference value (corrected angular velocity reference value) of the vibration detection signal (output of the first A / D conversion unit 32) obtained from the angular velocity sensor 12.
Then, the reference value calculated by the reference value calculation unit 34 is subtracted from the output of the first A / D conversion unit 32 by the subtraction unit 43.
The target position calculation unit 36 calculates the target position of the blur correction lens group 6 based on the output of the angular velocity sensor 12 after the reference value is subtracted by the subtraction unit 43.

The center bias calculation unit 37 biases the centripetal force for moving the image blur correction lens 6 toward the center of the movable range based on the target position of the image blur correction lens 6 calculated by the target position calculation unit 36. Calculate as a quantity.
Then, the control position of the image blur correction lens 6 is calculated by subtracting the calculated bias amount from the target position of the image blur correction lens 6.
By performing the centering bias processing in this way, it is possible to effectively prevent the image blur correction lens 6 from colliding with the hard limit, and it is possible to improve the appearance of the captured image.

  The drive amount calculation unit 39 is a blur correction lens group obtained from the target position from the target position calculation unit 36 and the value detected by the lens position detection unit 21 and A / D converted by the second A / D conversion unit 33. 6 is used to calculate the driving amount of the blur correction lens group driving mechanism 9.

The image sensor 3 is provided on the planned focal plane of the photographing optical system. The image pickup device 3 is composed of a device such as a CCD or a CMOS, and generates an analog image signal by photoelectrically converting an input subject image.
The signal processing unit 40 performs predetermined processing on the image signal generated by the image sensor 3. Actually, in order to obtain a motion vector with the configuration of FIG. 1, the mirror is raised, a through image (live view) is obtained, and calculation is performed in a state where light (image) reaches the image sensor 3.

The motion vector calculation unit 41 calculates a motion vector (first motion vector) indicating the motion (motion direction, amount of motion) of the image from the captured image processed by the signal processing unit 40.
Specifically, the motion vector calculation unit 41 detects the motion direction and the motion amount of the image by comparing the luminance information included in two consecutive frame image data captured by the image sensor 3. Calculate the motion vector. Actually, a motion vector equivalent to camera shake is calculated from the motion of the image.

The center bias removing unit 38 is a bias amount calculated by the center bias calculating unit 37 (subtracted from the target position of the image blur correction lens 6) from the first motion vector (MV1) that is the output of the motion vector calculating unit 41. Is subtracted.
The reference value correction amount calculation unit (reference value correction unit) 35 calculates a reference value correction amount based on the second motion vector (MV2) from which the center bias amount has been removed by the center bias removal unit 35.
Then, the subtraction unit (reference value correction unit) 42 subtracts the reference value correction amount obtained by the reference value correction amount calculation unit 35 from the output of the reference value calculation unit 34.

Next, an operation flow of the shake correction apparatus 100 according to the present embodiment will be described.
FIG. 3 is a flowchart showing an operation flow of the shake correction apparatus 100 of the present embodiment.

  After the camera 1 is turned on, the shake correction apparatus 100 starts a calculation for optical image stabilization. Depending on the camera, when the half-push switch 45 is pressed, the shake correction apparatus 100 starts calculation for optical image stabilization (step S001).

After the output of the angular velocity sensor 12 is amplified by the amplification unit 31, it is A / D converted by the first A / D conversion unit 32 (step S002).
The reference value calculation unit 34 calculates a reference value (a value corresponding to zero deg / s) of the calculated angular velocity based on the signal after A / D conversion of the output of the angular velocity sensor 12. Since the reference value of the angular velocity changes depending on the temperature characteristic, the drift characteristic immediately after startup, etc., for example, the stationary output of the angular velocity sensor 12 at the time of factory shipment cannot be used as the reference value.

  As a method for calculating the reference value, a method of calculating a moving average for a predetermined time and a method of calculating by LPF processing are known. In the present embodiment, reference value calculation by LPF processing is used.

  4A and 4B are diagrams for explaining the reference value calculation unit 34. FIG. 4A shows the reference value calculation unit 34 (HPF), and FIG. 4B shows the LPF 34a of the reference value calculation unit 34. .

  The cut-off frequency fc of the LPF 34 is generally set to a low frequency of about 0.1 [Hz]. This is because camera shake has a dominant frequency of about 1 to 10 [Hz]. If the fc is 0.1 [Hz], there is little influence on the camera shake component, and good blur correction can be performed.

  However, during actual shooting, low-frequency motion such as fine adjustment of the composition (a level at which panning cannot be detected) is added, which may cause an error in the ω0 calculation result. In addition, since fc is low (time constant is large), there is a problem that it takes time to converge to a true value when the error is once increased. In the present embodiment, this ω0 error is corrected.

Returning to FIG. 3, when the information of the first motion vector MV1 is updated (S004, YES), the process proceeds to S005, and when it is not updated (S004, NO), the process proceeds to S006. The description of S004 to S005 will be described later in detail.
In addition, since information on the first motion vector MV1 cannot be obtained during exposure, this step is performed until immediately before the exposure.
The outputs of the angular velocity sensor 12 after subtracting the reference value are integrated, and the target position of the shake correction lens group 6 is calculated based on the focal length, subject distance, shooting magnification, and shake correction lens characteristic information (S006).
Center bias processing is performed to prevent the blur correction lens group 6 from reaching the movable end (S007).

  There are various methods for the center bias processing, such as a method for setting a bias amount in accordance with the target position information, an HPF processing (in S006), and the method is not limited here.

The lens driving amount is calculated from the difference between the target position information including the center bias component and the blur correction lens position information (S008).
The blur correction lens group 6 is driven to the target position (S009), and the process returns to S002.

Next, reference value correction (S004 to S005, S011 to S016) will be described. FIG. 5 is a flowchart showing the reference value correction calculation.
As described above, when the information of the first motion vector MV1 is updated (S004), the process proceeds to S005. If it has not been updated, the process proceeds to S006.
Since the optical blur correction control cycle is sufficiently early with respect to the MV1 update cycle, the same arithmetic processing as normal image stabilization is performed until the MV1 is updated. Here, it is assumed that the control period of optical blur correction is 1 [ms] and the update period of the first motion vector MV1 is 33 [ms] (= 30 [fps]). A well-known technique is used for the calculation method of the first motion vector MV1.

All the received first motion vectors MV1 are summed (S011).
The center bias component calculated in S007 is converted to the same scale as the first motion vector MV1 (S012).
The conversion method is calculated based on the focal length, the subject distance, the shooting magnification, and the resolution information of the first motion vector MV1.
Bias_MV = Bias_θ * f (1 + β) / MV_pitch

Bias_MV: Center bias component (same motion vector scale)
Bias_θ: Center bias component (angle)
f: Focal length β: Image magnification MV_pitch: MV1 pitch size

  In addition, since a delay time occurs until the first motion vector MV1 is detected, it is preferable that the center bias component also has a delay time equivalent to that of the first motion vector MV1. For example, if there is a delay time of 3 frames at 30 [fps], the delay is about 100 [ms]. Therefore, the center bias component included in the first motion vector MV1 can be calculated more accurately by using the bias information before 100 [ms].

The center bias component calculated in S012 is subtracted from the first motion vector MV1 (S013). Thereby, the information of the second motion vector MV2 due to the reference value error can be acquired.
A difference: MV_diff between the latest second motion vector MV2 (n) and the second motion vector MV2 (n-1) one frame before is acquired (S014).
An amount for correcting the reference value is set based on MV_diff. As the reference value, a correction amount is set based on the following idea (S015).

MV_diff> 0: ω0_comp = −ω0_comp_def
MV_diff <0: ω0_comp = + ω0_comp_def
MV_diff = 0: ω0_comp = 0

ω0_comp: reference value correction amount ω0_comp_def (f): reference value correction constant f: focal length

Here, in this embodiment, ω0_comp_def (f) is a function of the focal length. FIG. 6 is a graph showing the relationship between the focal length and the reference value correction amount.
The longer the focal length, the greater the influence of the reference value error on the imaging surface. For this reason, even if the reference value error is a minute value, it can be detected as a motion vector, so the correction amount may be small.
Conversely, when the focal length is short, the influence of the reference value error on the imaging surface becomes small. For this reason, it cannot be detected as a motion vector unless there is a certain amount of error. Therefore, when the focal length is short, it is necessary to increase the reference value correction amount.

  Further, when the focal length is further shortened (below fth in FIG. 6), the influence of camera shake itself is small. For this reason, it is preferable not to perform the reference value correction using the motion vector.

In the present embodiment, since the reference value correction amount changes according to the focal length, the reference value correction can be performed satisfactorily by this process even when the focal length changes.
In S016, ω0_comp calculated in S015 is subtracted from the reference value calculated in S003 (FIG. 5). Specifically, the value of V4 ′ in FIG. 4B is corrected.

  The correction of the reference value using the motion vector is only during the exposure preparation period (during half-push vibration isolation and during moving image shooting), and normal reference value calculation is performed during exposure.

(Second Embodiment)
In the first embodiment, the correction value gain is changed according to the focal length. However, in the second embodiment, whether or not the reference value is corrected is determined according to the focal length, and the threshold value of the motion vector 2 is changed. .

Hereinafter, a description will be given using the waveforms of FIG. FIG. 7 shows difference data MV2_diff (the portion of S014 in FIG. 5) of the motion vector 2 (after removal of the center bias component) from the previous frame.
7A and 7B both have the same reference value error, but have different focal lengths. FIG. 7A shows Tele with a long focal length, and FIG. 7B shows Wide with a short focal length. In the case of (focal length: (a)> (b)), the range of the vertical axis is the same.

In the waveform of FIG. 7A, when MV2_diff exceeds MV_th1, the angular velocity reference value is corrected by a predetermined value.
If the same processing is performed when the focal length is shortened, as shown in FIG. 7B, there are few cases where MV2_diff exceeds MV_th1, and the reference value can be corrected accurately. Can not.
For this reason, in this embodiment, when the focal length is short, the threshold value is also reduced.

Here, it is conceivable that the threshold value is set to MV_th2 even when the focal length is long. However, as shown in a portion surrounded by an ellipse in FIG. 7A, which is a graph showing the relationship between the focal length and the reference value correction threshold, the reference value is also reacted in response to a minute change amount that is a noise component. Will be corrected. For this reason, depending on the case, it may be a factor of deteriorating the reference value.
Therefore, the reference value can be corrected more accurately by setting an appropriate threshold according to the focal length. FIG. 8 is a graph showing the relationship between the focal length and the reference value correction threshold. In the present embodiment, as in the first embodiment, the threshold value and the correction amount may be changed depending on the focal length.

(Third embodiment)
FIG. 9 is a block diagram of a shake correction apparatus 300 according to the third embodiment. The difference from the shake correction apparatus 100 of the first embodiment shown in FIG. 2 is that the resolution information is transmitted from the motion vector calculation unit 41 to the reference value correction amount calculation unit 35, and the optical information is the reference value correction amount calculation unit 35. It is a point that is not transmitted to.
In the present embodiment, the reference value correction amount or the threshold value is changed according to the resolution of the motion vector detection unit based on the same idea as in the first embodiment and the second embodiment.
This is because doubling the motion vector detection resolution and doubling the focal length can be regarded as equivalent motion vector detection accuracy.
FIG. 10 is a diagram showing the relationship between the motion vector detection resolution and the reference value correction amount.
FIG. 11 is a diagram showing the relationship between the motion vector detection resolution and the reference value correction threshold.
In the present embodiment, since the reference value correction amount changes according to the resolution, even when the focal length changes, good reference value correction can be performed.

(Fourth embodiment)
FIG. 12 is a block diagram of a shake correction apparatus 400 according to the fourth embodiment. A difference from the shake correction apparatus 100 of the first embodiment shown in FIG. 2 is that resolution information is transmitted from the motion vector calculation unit 41 to the reference value correction amount calculation unit 35.
FIG. 13 is a graph showing the relationship between the focal length, resolution, and reference value correction amount in the fourth embodiment. FIG. 14 is a graph showing the relationship between the focal length, the resolution, and the threshold in the fourth embodiment.
In the present embodiment, the reference value correction amount is changed by the focal length and the motion vector detection resolution as in the third embodiment for the same reason as in the first embodiment, or for the same reason as in the second embodiment. Change the threshold.
As described above, even when the focal length and the motion vector detection resolution are changed, more accurate reference value correction can be performed.

As described above, according to the present embodiment, when the gyro reference value is corrected using the motion vector information, the correction amount is changed according to the focal length. With this process, the reference value can be corrected more accurately even when the focal length changes.
Similarly to the above, by changing the correction amount according to the motion vector detection resolution, the reference value can be corrected more accurately even when the body changes or the resolution changes depending on the shooting situation. Is possible.

(Deformation)
The present invention is not limited to the above-described embodiment, and various modifications and changes as described below are possible, and these are also within the scope of the present invention.
In the present embodiment, the form of performing the shake correction by moving the shake correction lens group has been described, but the present invention is not limited to this. For example, blur correction may be performed by moving the image sensor, or blur correction may be performed by moving the blur correction lens group and the image sensor.
In addition, although embodiment and a deformation | transformation form can also be used in combination as appropriate, detailed description is abbreviate | omitted. Further, the present invention is not limited to the embodiment described above.

  1: camera, 1A: camera housing, 1B: lens barrel, 2A: camera CPU, 2B: lens CPU, 3: image sensor, 4: zoom lens group, 5: focus lens group, 6: blur correction lens group, 7: Zoom lens group drive mechanism, 8: Focus lens group drive mechanism, 9: Blur correction lens group drive mechanism, 12: Angular velocity sensor, 21: Lens position detection unit, 31: Amplification unit, 32: First A / D conversion unit 33: second A / D conversion unit, 34: reference value calculation unit, 35: center bias removal unit, 35: reference value correction amount calculation unit, 36: target position calculation unit, 37: center bias calculation unit, 38: center Bias removal unit, 39: drive amount calculation unit, 40: signal processing unit, 41: vector calculation unit, 42: reference value correction unit, 43: subtraction unit, 100, 300, 400: blur correction device

Claims (12)

A drivable blur correction element that corrects blur of a subject image formed by the optical system;
An angular velocity sensor for detecting an angular velocity of an optical device including the optical system;
A reference value calculation unit for calculating a reference value of the output signal of the angular velocity sensor;
Information on a motion vector calculated from the subject image formed by the optical system is received, and a reference value correction value calculated from a correction amount determined in advance according to the motion vector and the focal length of the optical system A reference value correction unit for correcting the reference value;
Based on the output signal of the angular velocity sensor and the corrected reference value, a target position calculation unit that calculates a target position of the blur correction element;
An image stabilization apparatus having The shake correction apparatus according to claim 1,
The correction amount when the focal length of the optical system is f1 is larger than the correction amount when the focal length of the optical system is f2 longer than f1.
Blur correction device. The shake correction apparatus according to claim 1 or 2,
The reference value correction unit does not correct the reference value when the focal length of the optical system is equal to or less than a first threshold;
Blur correction device. The blur correction device according to any one of claims 1 to 3, wherein
The reference value correction value changes according to the detection resolution of the motion vector.
Blur correction device. The blur correction device according to any one of claims 1 to 4, wherein
The reference correction unit corrects the reference value when the difference between the motion vectors in different frames is larger than a second threshold. The shake correction apparatus according to claim 5,
The blur correction device in which the second threshold when the focal length of the optical system is f1 is smaller than the second threshold when the focal length of the optical system is f2 longer than f1. A drivable blur correction element that corrects blur of a subject image formed by the optical system;
An angular velocity sensor for detecting an angular velocity of an optical device including the optical system;
A reference value calculation unit for calculating a reference value of the output signal of the angular velocity sensor;
A reference value correction unit that corrects the reference value using a motion vector calculated from a plurality of the subject images, and changes a correction amount for correcting the reference value according to the detection resolution of the motion vector;
Based on the output signal of the angular velocity sensor and the corrected reference value, a target position calculation unit that calculates a target position of the blur correction element;
An image stabilization apparatus having The blur correction device according to claim 7,
The correction amount of the reference value in which the detection resolution of the motion vector is d1 is larger than the correction amount of the reference value in the case of d2 whose resolution is higher than d1.
Blur correction device. The shake correction apparatus according to claim 6 or 7,
The blur correction device, wherein the reference value correction unit does not correct the reference value when the detection resolution is lower than a third threshold. An interchangeable lens that is detachably attached to the camera body,
A blur correction device according to any one of claims 1 to 9, comprising:
The blur correction element is a drivable blur correction optical system that is at least part of the optical system and corrects blur of the subject image.
interchangeable lens. The blur correction device according to any one of claims 1 to 9, wherein
The blur correction element is an imaging element that captures the subject image formed by the optical system.
Blur correction device. A camera comprising the shake correction device according to any one of claims 1 to 11.

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