JP3254689B2 - Camera that can detect and correct blur - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a blur of a subject image, corrects the blur of the subject image by driving at least a part of a photographing optical system during film exposure, and detects a blur-free photograph. And a camera capable of correction.

[0002]

2. Description of the Related Art Conventionally, a shake detection camera or a shake correction camera using an image sensor has been proposed. The speed and direction of the blurring of the subject image change every moment, and particularly when the blurring is caused by hand shake.
Therefore, in order to sufficiently correct the blur, use “Blur Detection” →
The operation of “correction by driving the optical system” needs to be repeated continuously and many times throughout the exposure. On the other hand, a conventional camera that performs shake detection and correction repeatedly performs shake detection and correction with a certain period of time.

On the other hand, the repetition cycle of the above-described blur detection / correction needs to be shortened as the focal length of the photographing lens becomes longer. The reason is briefly described below. FIG. 17 is a diagram showing the relationship between the focal length of the photographing lens and blur. FIG.
In (A), the focal length is f, the distance from the subject to the lens is b, and the distance from the lens to the film is a.
The image of the point A on the subject is A '.

FIG. 17B shows a state in which a camera shake having an amplitude θ occurs in the camera in the state shown in FIG. 17A and the position of the point A ′ vibrates at an angular frequency ω. When the camera is moved downward by θ / 2 on the figure, the point A is the position of the point Ad when viewed from the camera, and the point A on the film surface is
An image is formed on d '. In addition, when the camera is moved upward by θ / 2 in the figure, the point A becomes the position of the point Au when viewed from the camera,
An image is formed on a point Au ′ on the film surface.

[0005] Here, an intersection of the optical axis and the film surface is defined as a point O, and the x-axis is taken upward from the point O. And point O and point A '
Assuming that the distance between the points is x and the point A ′ vibrates sinusoidally on the film surface, the position of the point A ′ is represented by {x = atan (θ / 2) · sinωt (t is time)}. be able to. FIG. 18 is a graph of this. In FIG. 18, the intervals of t _i , t _{i + 1} , and t _{i + 2} are the repetition period ts of blur detection and correction. It is assumed that a shake between t = t _i and t = t _{i + 1} is detected with respect to the shake as shown in the figure. Next, at t = t _{i + 1} , it is predicted that blurring will continue at the detected blurring speed thereafter (straight line 1 in the drawing), and the correction optical system is driven to cancel this. At this time, t =
The difference between the actual blur (2 in the figure) and the predicted blur (1 in the figure) between t _{i + 1} and t = t _{i + 2} is the blur correction error.

As can be seen from FIG.
The blur correction error increases as (θ / 2) increases. On the other hand, the distance a from the lens to the film is given by an imaging formula ◇ 1 / a + 1 / b = 1 / f and a = bf / (b−
f) ◇ In normal shooting, b ≒ f, so a ≒ f, and it can be said that the blur amplitude atan (θ / 2) is proportional to the focal length of the lens. Therefore, the blur correction error increases as the focal length of the taking lens increases.

On the other hand, as can be seen from FIG. 18, in order to keep the blur correction error small, the repetition period t _s may be shortened. Therefore, in order to perform appropriate blur detection / correction, it is necessary to shorten the repetition period as the focal length of the photographing lens increases.

[0008]

As described above, the longer the focal length of the photographing lens, the shorter the repetition period of blur detection / correction. On the other hand, when blur detection is performed using an image sensor, it is necessary to lengthen the repetition period in order to detect blur even for a low-luminance subject. This is because it is necessary to increase the integration time of the image sensor for a low-luminance subject.

On the other hand, in the conventional camera capable of detecting and correcting blur, the repetition cycle is constant. Therefore, if the repetition period is set short so that appropriate blur correction can be performed even with a lens having a long focal length, there is a problem that blur detection of a low-luminance object becomes impossible. Conversely, if the repetition period is set to be long so that blur detection can be performed even with a low-luminance subject, there is a problem that a blur correction error increases with a photographing lens having a long focal length.

Accordingly, an object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, perform proper blur detection and correction even with a lens having a long focal length, and perform blur detection and correction even for a low-luminance object. It is to provide a camera.

[0011]

In order to achieve the above object, a camera capable of detecting and correcting a blur according to the present invention comprises an image sensor for capturing an image of a subject, and a blur of the subject image based on image data output from the image sensor. Calculation means for calculating the data of the camera, blur correction means for driving a part of the photographic optical system of the camera based on the data of the blur calculated by the calculation means to perform blur correction, and focal length information of the photographic optical system. Input means for inputting, and determining means for determining a cycle of blur correction based on the focal length information , wherein the determining means
The longer the focal length of the shooting optical system, the longer the
The shorter the focal length, the longer the cycle of blur correction . Further, the camera capable of detecting blur according to the present invention includes an image sensor that captures an image of a subject, an arithmetic unit that calculates blur data of the subject image based on image data output by the image sensor, and focal length information of an imaging optical system. input means for inputting a, and a determining means for determining a period of the vibration detected based on the focal length information, the decision
The longer the focal length of the imaging optical system, the longer the
Period, the shorter the focal length, the longer the period of blur detection
Characterized in that it. Further, the camera capable of detecting blur according to the present invention includes an image sensor that captures an image of a subject, an arithmetic unit that calculates blur data of the subject image based on image data output by the image sensor, and focal length information of an imaging optical system. input means for inputting a, and a changing means for changing the maximum value of the integration time of the image sensor based on the focal length information, said changing means, the focus of the imaging optical system
The longer the distance, the smaller the maximum value of the integration time
The maximum value of the integration time is increased as the distance is shorter .

[0012]

According to the above arrangement, the cycle of repetition of blur detection and correction is switched according to the focal length of the photographing optical system. When the focal length is short, switching is performed so that the cycle is long, and when the focal length is long, switching is performed so that the cycle is short. Further, the maximum value of the integration time of the image sensor used for blur detection is switched according to the focal length of the photographing optical system. The switching is performed such that the maximum value of the integration time is increased when the focal length is short, and is reduced when the focal length is long.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a main part of a camera shake detection camera according to the present invention.

Referring to FIG. 1, photometric SPD (Sili)
con Photodiode) 2 is input to the photometric circuit 3. The photometric circuit 3 calculates the output of the SPD 2 and outputs the calculation result to the main CPU 1. The photographing lens 4 is replaceable, and the drive of the aperture and the focus adjustment are performed through the aperture drive means 5 and the focus adjustment drive means 6. The photographing lens circuit 7 stores an F value, a focal length, and various parameters for blur correction of the lens unique to the photographing lens 4. The taking lens circuit 7 further includes an actuator for driving an optical system for blur correction and a control circuit therefor.

The AF detecting mirror 8 guides a part of the light beam passing through the photographing lens 4 to the phase difference type AF detecting module 13. The AF detection mirror 8 is retracted by the AF detection mirror driving means 9 so as not to block light to the film at the time of film exposure. Shutter curtain 1 of focal plane shutter
0 includes a front curtain and a rear curtain, and the shutter curtain driving unit 11
Driven by The switch S1 is turned on by the first stroke of the shutter button to perform photometry and AF operation. The switch S2 is turned on by the second stroke of the shutter button. The film winding means 14 winds and rewinds the film. The switch SC is a switch for operating the continuous shooting mode.

The blur detecting optical system 18 is an optical system for guiding light to a later-described blur detecting CCD.

Reference numeral 12 denotes camera shake detection and correction means for detecting and correcting camera shake. Reference numeral 12 includes an arithmetic unit for performing a shake calculation and a control CPU for controlling a shake correction optical system. The camera shake detection and correction means 12 will be described later in detail.

The main CPU 1 is further connected to an exposure correction amount input means 16 for performing exposure correction for an exposure amount determined by a photometric value and a film sensitivity setting means 17 for setting a film sensitivity.

FIG. 2 is a view showing an optical system of the camera shake detection camera according to the present invention. With reference to FIG.
Includes a shake correction lens 20 and a shake correction lens driving device 21 for moving the shake correction lens 20. Since the details of the correction lens driving device 21 are known, the description thereof is omitted. The pellicle mirror 22 is fixed in the camera body 32, and a part of the light beam that has passed through the photographing lens 4 is reflected toward the finder optical system, and the rest is transmitted toward the shutter curtain 10. Part of the light beam transmitted through the pellicle mirror 22 is guided by the AF detection mirror 8 toward the phase difference AF detection module 24. The AF detection mirror 8 is retracted by the AF detection mirror driving means 9 (not shown) to a position where the light flux during exposure that reaches the film during exposure of the film is not blocked.

The light beam reflected by the pellicle mirror 22 passes through the condenser lens 25 and passes through the pentaprism 2.
Enter 6. A photometric SPD 2 is provided on the eyepiece 27 side of the pentaprism 26. One surface 26a of the pentaprism 26 is a half mirror, and takes out a part of the incident light beam outside the ventr prism 26. The extracted light beam passes through the blur detection optical system 18 and is reflected by the reflecting mirror 28 to reach the blur detection sensor 29. The blur detection optical system 18 re-images the image on the finder focal plane 30 onto the blur detection sensor 29. The blur detection sensor 29 is a CCD area sensor. The pentaprism 26 is not limited to the glass block type, but may be a hollow pentamirror having an air layer inside.

As described above, in the present invention, since the light of the subject is transmitted to the area sensor 29 serving as a blur detection sensor by using the velcro mirror 22, blur detection is performed by an image detection method in a TTL camera. Further, since the pentaprism 26 is used in the optical path to the blur detection sensor 29,
There is no need to provide a separate optical path to the light source.

FIG. 3 is a view showing a finder screen. In FIG. 3A, a is a transparent blur detection area, and this area secures an optical path to the sensor 29 and increases the amount of light to the sensor 29. An area represented by b is a mat portion of the finder screen, where light is scattered, an image is formed thereon as in the past, and focus is detected. The area indicated by a is also used for displaying the finder display frame of the blur detection area. FIG. 3B is a diagram showing a case where the entire surface of the finder screen is transparent. A part a near the center of the finder screen b is imaged on the imaging surface by the blur detection optical system 18. This image is used by the blur detection sensor 29.

Referring to FIG. 2, the photographing lens 4 is mounted on a camera body 32 via a lens mount 31 and is interchangeable.

When a normal lens without a camera shake correction lens is attached to the camera body 32,
When blur is detected, a warning is displayed on the finder screen. A warning of camera shake may be given to the electronic finder with the text “Caution for camera shake”.

Next, referring to FIG.
2 will be described. The camera shake detection sensor 29 includes a CCD imaging unit 41, an output amplifier 42 that amplifies the CCD output,
An illuminance monitor 43 for controlling the integration time of the CCD;
And a photometric circuit 44. The clock generator 45
The output of the photometric circuit 44 is detected, and the integration time of the CCD and the gain of the output amplifier are set. The clock generator 45 also generates a driving clock for the CCD, and a clock for the A / D converter 51, the D / A converter 48, the sensitivity variation correction memory 49, and the dark output correction memory 50. The output of the shake detection sensor 29 passes through the differential amplifier 46 and the gain control amplifier 47,
1 is input. The dark output correction memory 50 and the sensitivity variation correction memory 49 store data for correcting the sensitivity variation of the CCD and the dark output, respectively. The dark output correction memory 50 outputs data to the D / A converter 48. The output signal of the D / A conversion is input to the differential input of the differential amplifier 46. Thereby, the dark output of the CCD 41 is corrected. The gain control amplifier 47 is an amplifier whose amplification is controlled by a digital signal. The gain control amplifier 47 has a sensitivity variation correction memory 49
Is controlled by the sensitivity variation correction data stored in the CPU, and the sensitivity variation of the CCD output is corrected.

The output signal of the A / D converter 51 is stored in the reference memory 52 or the reference memory 53. The address generator 54 includes the reference unit memory 52 and the reference unit memory 5.
3 generates address data necessary for the operation of each memory.

The arithmetic unit 55 includes a subtraction circuit 56, an absolute value circuit 57, an addition circuit 58 and a register 59. Data of the reference unit memory 52 and the reference unit memory 53 are provided as inputs.

The calculation result from the calculator 55 is stored in a correlation result memory 60 and a vertical contrast memory 61 according to the type of calculation.
Alternatively, it is stored in one of the horizontal contrast memories 62. These memories are connected to the control CPU 63 and can be accessed from the control CPU 63. The control CPU 63 also controls the address generator 54 and the clock generator 45.

Next, a method of detecting a shake and a calculation of a shake amount will be described. First, a blur detection sequence will be described. In the present invention, a subject image is detected two-dimensionally using an area sensor 29 capable of detecting two-dimensional image data.
Image blur is detected by detecting a time shift of the subject image using the area sensor 29.

The CCD 41 is an area sensor of I × J pixels. The reference section memory 52 and the reference section memory 53 are memories of I × J words, respectively, and the correlation result memory 60
Is a memory having a capacity of H × H words. CCD4
It is assumed that one light receiving surface is divided into M × N blocks. Each block is composed of adjacent K × L pixels. The vertical contrast memory 61 and the horizontal contrast memory 62 each have M
It is a memory having a capacity of × N words. Hereinafter, the procedure of blur detection will be described. Here, I = 68, J = 52,
Let K = 8, L = 8, M = 8, N = 6, H = 5. A /
It is assumed that the resolution of the D converter 51 is 8 bits, the register 59 is 14 bits, and one word of the correlation result memory 60, the vertical contrast memory 61, and the horizontal contrast memory 62 is represented by 14 bits.

FIG. 5 is a schematic diagram of a part of the light receiving section of the CCD 41. One small square grid represents a unit pixel. In the figure, the lower left pixel is a pixel (1, 1), and the upper right pixel is a pixel (68, 52). Except for the two pixels on the outer periphery of the light receiving unit, the light receiving unit of the CCD 41 is divided into blocks each composed of 8 pixels × 8 pixels. The portion surrounded by a thick line in the figure corresponds to each block. The lower left block is a block (1, 1), and the upper right block is a block (8, 6).

The blur detection sequence is roughly divided into three parts: {(1) contrast calculation and block selection} (2) correlation calculation {(3) interpolation calculation}.

The contrast calculation is a calculation performed for selecting a block. Each part of the subject imaged on the light receiving part of the CCD 41 has a part suitable for blur detection and a part not suitable for blur detection. In this embodiment, the contrast of the subject is calculated in order to select a portion suitable for blur detection. The contrast of the subject is calculated for each block, and blur detection is performed using a total of eight blocks, four blocks with high contrast in the vertical direction and four blocks with high contrast in the horizontal direction.

(1) Description of Contrast Calculation and Block Selection (1) First, the output of the CCD 41 is stored in both the reference memory 52 and the reference memory 53. Using this data, the vertical and horizontal contrasts of each block are calculated. The calculation is block (1,1),
(2,1),..., (7,6), (8,6) horizontal contrast, block (1,1), (2,1),.
6) and (8, 6) in order of vertical contrast.

The output of the pixel (i, j) of the CCD 41 is represented by A
As (i, j), the horizontal contrast of the block (k, *) is

[0036]

(Equation 1)

The vertical contrast

[0038]

(Equation 2)

Is defined as

However, * is a symbol added in the text to avoid confusion between the lowercase letter l (el) and the numeral 1. Therefore, * in the text means the same as the cursive letter L in drawings and mathematical formulas.

The procedure for executing this calculation formula on the hardware shown in FIG. 4 will be described below. The contents of the reference section memory 52 corresponding to the output of the pixel (i, j) of the CCD 41 are represented by R (i,
j), the content of the reference unit memory 53 is S (i, j).
First, the register 59 is cleared. Next, the subtractor 56
R (i, j) to one input and S (i +
1, j)} where i = 8 (k-1) +2 and j = 8 (* −
1) Address generator 5 so that｝ which is +2 is given
4 sends the address. The data subtracted by the subtraction circuit 56 has an absolute value obtained by an absolute value circuit 57, is added to the content of a register 59 by an addition circuit 58, and is stored in the register 59. Next, an address to be i = i + 1 is transmitted from the address generator 54, and the same calculation is performed.
Thus, i = 8 (k-1) +2 to 8k + 2, j
= 8 (*-1) +3 to 8 * + 2, the register 59 stores

[0042]

(Equation 3)

Has been stored.

Reference unit memory 52 and reference unit memory 53
Have the same contents A (i, j) stored therein.
Since (i, j) = R (i, j) = S (i, j),
The contents of register 59 are horizontal contrast

[0045]

(Equation 4)

Is as follows. When the calculation for one block has been completed, the contents of the register 59 are transferred to the horizontal contrast memory 60 corresponding to the block and stored.

Similarly, the horizontal contrast of all the remaining blocks is obtained by calculation and stored in the horizontal contrast memory 62.

Next, the vertical contrast is calculated.
First, the register 59 is cleared as in the case where the horizontal contrast is calculated. Next, R (i, j) is input to one input of the subtraction circuit 56, and S (i, j + 1) is input to the other input.
｛Where i = 8 (k−1) +3, j = 8 (* − 1) +2,
The address is sent from the address generator 54 so that 与 え is given. The data subtracted by the subtraction circuit 56 has an absolute value obtained by an absolute value circuit 57, is added to the content of a register 59 by an addition circuit 58, and is stored in the register 59. Next, an address to be i = i + 1 is sent from the address generator 54, and the same calculation is performed. Thus, i = 8 (k-1) +3 to 8k + 2, j = 8
Processing is performed in the range of (* -1) +2 to 8 * + 2.
As a result, the register 59

[0049]

(Equation 5)

Is stored. Where A (i, j) =
Since R (i, j) = S (i, j), the register 72
Is vertical contrast

[0051]

(Equation 6)

Is as follows. When the calculation for one block is completed, the contents of the register 59 are stored in the vertical contrast memory 61.
Is transferred and stored in a location corresponding to that block.

Similarly, the vertical contrast of all the remaining blocks is calculated and stored in the vertical contrast memory 61.

The control CPU selects the block having the highest contrast from the vertical and horizontal contrasts of each block obtained as described above. Next, a block having the highest contrast is selected from the remaining blocks in a direction different from the direction of the contrast previously selected (for example, in the case of selecting the vertical direction first, the horizontal direction). In the same manner, eight blocks (four in each of the vertical and horizontal directions) are selected in the order of the blocks having the highest contrast while changing the direction of the contrast. Selected block B
1 to B8.

(2) Description of Correlation Calculation As the contents of the reference memory 52, data on which the contrast has been calculated is left as reference image data. New data is read from the CCD 41 one after another, and each time it is written to the reference memory 53 as a reference image. Each time new data is written in the reference section memory 53, the reference image and the reference image are compared, and a spatial shift between the two is detected as image blur. Image blur is obtained by correlation calculation and interpolation calculation described below.

The block Bk (k = 1, 2,..., 8)
Define the correlation value of

[0057]

(Equation 7)

Considering the case where * = m = 0,

[0059]

(Equation 8)

Is as follows. This value is obtained by adding the absolute value of the difference between the data of the same pixel in the reference image and the reference image for one block. Considering the case other than * = m = 0, C
k (*, m) is obtained by adding one block of the absolute value of the difference between the data of the pixel (i, j) of the reference image and the data of the pixel (i ++, j + m) of the reference image. The correlation value obtained by adding the correlation values for 8 blocks

[0061]

(Equation 9)

It is assumed that

One input of the subtraction circuit 56 is connected to the reference memory 52, and the other input is connected to the reference memory 53. Therefore, after the register 59 is cleared, R (i, j) is input to one input of the subtraction circuit 56, and S (i ++, j + m) is input to the other input. Then, the control CP is processed so that data in a predetermined range of i and j is processed.
The address determined by U is sent from the address generator 54. Then, C (*, m) is obtained in the register 59. This is transferred to a predetermined address of the correlation result memory 60 and stored. By changing the values of * and m and repeating the above processing, C (*, m):
(*, M = -2, -1, 0, 1, 2) are all obtained.

(3) Description of Interpolation Calculation When the calculated correlation values C (*, m) are arranged with * on the horizontal axis and m on the vertical axis, an array like a number is obtained.

C (-2,2) C (-1,2) C (0,2) C (1,2) C (2,2) ◇ C (-2,1) C (-1,1) C (0,1) C (1,1) C (2,1) ◇ C (-2,0) C (-1,0) C (0,0) C (1,0) C (2,0 ) ◇ C (-2, -1) C (-1, -1) C (0, -1) C (1, -1) C (2, -1) ◇ C (-2, -2) C ( -1, -2) C (0, -2) C (1, -2) C (2, -2) ◇ If there is no deviation between the reference image and the reference image, C
(0,0) becomes 0, and has a larger value as it goes outside the array. Assuming that the reference image is shifted right by * ₀ pixel and m ₀ pixel upward with respect to the reference image, C
(* ₀ , m ₀ ) becomes 0, and has a larger value as it goes away from it. However, the image shift is not always an integral multiple of the pixel. Further, since the speed of the image blur is not constant, the blur of the image due to the image blur may be different between the reference image and the reference image. FIG. 6 shows the distribution of the correlation values C (*, m) in such a case by using contour lines. Referring to FIG. 6, values are actually obtained only on grid points in the figure, but contour lines are drawn assuming values between grids. The contour lines have smaller values toward the center. The center of the contour line is the MP point at the coordinates (x ₀ , y ₀ ), and the reference image is considered to be shifted by x ₀ horizontally and y ₀ vertically with respect to the reference image. Since only the values on the grid points are obtained by the correlation calculation, the MP points need to be obtained by interpolation using the data of the grid points. Magnification of blur detection optical system 18, CCD 41
Are set so that the MP point satisfies −1.5 <x ₀ , y ₀ <1.5, assuming the magnitude of the actual blur. The interpolation calculation after the completion of the correlation calculation will be specifically described. The calculation in the horizontal direction will be described. First C
Find the minimum value C (* ₀ , m ₀ ) of (*, m). * ₀
And (a) to (h) in FIGS. 7 and 8 according to the magnitude relationship between C (* _0-1 , m ₀ ) and C (* _{0 + 1} , m ₀ ).

(A) In the case of condition ◇ It is determined that 0 ≦ x ₀ <1. ◇ The point (-1, C (-1, m ₀ )) and the point (0, C (0, m
₀ )) and a line (i) connecting the point (1, C (1, m ₀ ))
And the straight line (ii) connecting the point (2, C (2, m ₀ )) and the * coordinate of the intersection point is x ₀ .

[0067]

(Equation 10)

(B) Condition 条件 It is determined that 1 <x ₀ <0. ◇ The points (−2, C (−2, m ₀ )) and (−1, C (−1,
m ₀ )) and a point (0, C (0, m)
₀ )) and a straight line (i) connecting the point (1, C (1, m ₀ )).
a * coordinate of the intersection of the i) and x _0.

[0069]

[Equation 11]

(C) Condition ◇ It is determined that 0 <x ₀ <1. ◇ The following is the same as in (a),

[0071]

(Equation 12)

(D) Condition ◇ It is determined that 1 ≦ x ₀ <2.直線 A straight line (i) connecting the points (0, C (0, m ₀ )) and (1, C (1, m ₀ )) and a straight line passing through (2, C (2, m ₀ )) i) reverse the sign of the linear (ii) the intersection of the of * coordinates to x _0.

[0073]

(Equation 13)

(E) Condition ◇ It is determined that −1 ≦ x ₀ <0. ◇ The following is the same as in (b)

[0075]

[Equation 14]

(F) Condition: It is determined that ◇ −2 <x ₀ <−1. ◇ The point (-1, C (-1, m ₀ )) and the point (0, C (0, m
₀ )) and a point (−2, C (−2, m)
₀ )), the * coordinate of the intersection of the straight line (ii) and the straight line (i) having the opposite sign is defined as x0.

[0077]

(Equation 15)

In the case of the conditions (g) and (h): It is determined that a shake exceeding the assumed maximum shake has occurred and that the shake amount cannot be detected.

Although the procedure for obtaining x ₀ has been described above, y ₀ can be similarly obtained.

Next, a method of driving the correction lens 20 shown in FIG. 2 will be described. FIG. 9 is a diagram for explaining a method of driving the correction lens 20. Here, only the horizontal component of the image blur is considered. In FIG. 9, the horizontal axis t represents time, and the vertical axis x represents the position of the image. t _-3 , t _-2 , t _-1 , ...
Represents the integration start time of the CCD 41, t- ₃ ",
t _-2 ", t _-1 ,"... represent integration completion times. If. Subject integration time TIi is represented by TI _i = t _i "-t _i is illuminated with an alternating current source, the exposure amount of CCD41 is changed integration time to be constant. Thus, the integration time Is not constant, the integration start time t _-3 ,
t _-2 , t _-1 , ... are equally spaced TS. Note that TS
Is called a correction cycle. A solid curve 301 indicates the locus of the image on the CCD 41 when there is image blurring.
If the blur correction by the correction lens 20 is not performed,
The image moves on this curve. Since the blur correction starts at t = t ₀ , the curve 301 is drawn so as to pass through the point (t ₀ , 0). A polygonal line 302 is a locus of the correction lens 20. A broken line 303 represents the locus of the image on the CCD 41 when the correction is performed by moving the correction lens 20. The points P _-2 , P _-1 , P ₀ , ... are integration periods t _{-3 to} t _-3 ",
_{t -2 ~t -2 ", t -1} ~t -1", indicating an average position of the image in .... CCD data obtained by integrating between t _i ~t _i "is read during _{t i + 1 ~t i + 2} , calculation processing is performed from .t i _{+ 2} position Pi of the image is obtained The correction lens 20 is driven by the obtained data.

In the following description, P _-2 , P _-1 , P
_{0, ... X 1, X 2} , X 3, ... X 1 ', X 2', X 3 ',
.. X ₀ ″, X ₁ ″, X ₃ ″,... Are the names of points and are also used as the x-coordinate values of the points.

In order to make correction from time t = t ₀ ,
It is necessary to find the blur speed between t ₀ and t ₁ . The speed of blurring is obtained from the changes in the image positions of the two recent points, and t _0-
It is predicted that the speed of the blur during t ₁ is the same. t
= Latest image position is known at time t ₀ is P _-1. The time from P- ₂ to P- ₁ is TS- (TI- _3- T
I ₋₂ ) / 2, the predicted value Vx ₀ of the blurring speed from t ₀ to t ₁ is

[0083]

(Equation 16)

Is as follows. Thus, between t ₀ ~t _1, the correction optical system is driven at a speed of Vx _0.

Next, consider the case at time t = t ₁ . At this time, since the correction lens 20 is driven at Vx ₀ , it is moved to the position of X ₀ ″. At this time, since the position of P ₀ is known, the predicted value Vx ₁ of the blurring speed from t _{1 to} t ₂ is calculated. Is required as follows.

[0086]

[Equation 17]

Since the speed Vx ₁ is obtained based on the latest image position data, it is considered that the predicted value of the blur speed between t ₀ and t ₁ is higher in accuracy than Vx ₀ . Therefore, to calculate the prediction error ERx ₁ as follows. _{◇ ERx 1 = (Vx 0 -Vx} 1) · TS ◇ position X ₁ of the image from these values t = t ₁ is predicted as follows. _{◇ X 1 = Vx 0 · TS} -G · ERx 1 ◇ = {Vx 0 -G (Vx 0 -Vx 1)} · TS ◇ G is referred to as prediction coefficients, in FIG. 9, the prediction coefficients G =
Case 2 is shown. Here, the correction lens 20 needs to be driven to the newly predicted point X ₁ , but the driving requires a time period from t ₁ to t ₁ ′. In the meantime, the image is X
_The correction lens 2 is expected to move to the position
0 _{◇ X 1 '= X 1 +} Vx 1 × (t 1' -t 1) is driven ◇ into position, between t ₁ '~t ₂ is driven at a speed of Vx _1.

Next, consider the case of time t = t ₂ . At this time, the correction lens has been moved to a position represented by X ₁ ″ = X ₁ + Vx ₁ · TS. At this point, since the position of P ₁ is known, the blurring speed between t _{2 and} t ₃ is predicted. value Vx ₂ can be calculated as follows.

[0089]

(Equation 18)

[0090] Vx ₂ is considered to be more accurate than Vx ₁ is as a prediction value of the motion velocity between t ₁ ~t _2. Therefore to calculate the prediction error ERx ₂ as follows. _{◇ ERx 2 = (Vx 1 -Vx} 2) · TS ◇ position X ₂ of the image from these values t = t ₂ are predicted as follows. {X ₂ = X ₁ ″ −G · ERx ₂ } = X ₁ + {Vx ₁ −G (Vx ₁ −Vx ₂ )} · TS Here, the correction lens 20 is driven to the newly predicted position X ₂ . it is necessary, but the drive 'is required time. during which the image is X _2' t ₂ ~t ₂ correcting lens 20 since it predicted to move to the position of _{◇ X 2 '= X 2 +} Vx 2 · It is driven to the position of (t ₂ ′ −t ₂ ) ◇, and is driven at the speed of Vx ₂ during t ₂ ′ to t ₃ .

Next, consider the case of time t = t ₃ . At this time, the correction lens X ₂ ″ is at a position represented by {X ₂ ″ = X ₂ + Vx ₂ · TS}. Predicted value Vx ₃ shift speed between t ₃ ~t ₄ because you know the position of P2 at this time
Can be calculated as follows.

[0092]

[Equation 19]

[0093] Vx ₃ obtains the prediction error ER ₃ because it is considered more accurate than Vx ₂ as the predicted value of the shake speed between t ₂ ~t ₃ as follows _{◇ ER 3 = (Vx 2 -Vx} 3 ) · TS ◇ position X ₃ of the image at t = t ₃ these values _{◇ X 3 = X 2 "-G} · ERx 3 ◇ = X 2 + {Vx 2 -G (Vx 2 -Vx 3)} TS ◇, where the correction lens 20 needs to be driven to the newly predicted position X ₃ , which is driven from t ₃ to
Time between t ₃ ′ is required. Since it can be predicted that the image during moving to the position of X ₃ ", the correction lens 20 is driven to _{◇ X 3 '= X 3 +} Vx 3 · (t 3' -t 3) ◇ position, t ₃ '~t ₄ while is driven at a speed of Vx _3.

Hereinafter, similarly, X ₄ , Vx ₄ , X ₅ ,
Vx _5, ... are determined, the correction optical system is driven.

In this embodiment, the prediction coefficient G is fixed. However, the value of G may be changed in the middle of the correction sequence depending on the situation of blur detection. Even if the number of times of the motion compensation is performed, if the prediction error ER is not reduced, or when the sign of the prediction error ER _i is not inverted, the prediction coefficient G may be large. Further, when the sign of the prediction error ER _i is constantly inverted, the value of G may be reduced.

[0096] Referring to FIG. 9, time TR from time t ₀ to t _z is a shooting exposure time of the camera. As can be seen from FIG. 9, the sequence for performing the camera shake correction is repeated many times within the photographing exposure time TR. Therefore,
The correction is not performed only once or twice, but is performed at least several times. In order to perform blur correction even for a low-luminance subject in such a correction method, it is preferable that the correction cycle TS be long and the integration time of the CCD 41 be long. However, if the TS is too large, a sufficient correction effect for fast shake cannot be obtained. As mentioned earlier, it is necessary to shorten the TS near a photographic lens with a long focal length, but according to experiments, TS = 1 with a 50 mm lens.
0ms, T = 2.5ms T with 200mm lens
The result that S was appropriate was obtained.

As described above, t _{i to} t _{i + i} in FIG.
Is TS, and the integration time t of the image sensor CCD 41 is
_{i to} t _i ″ cannot be longer than this. In the present embodiment, the TS is changed according to the focal length of the photographing lens in order to make the integration time as long as possible so that a low-luminance subject can be handled. TS = 1 for focal length less than 50mm
0 ms, 50 mm or more and less than 200 mm, TS = 5 ms,
For 200 mm or more, TS is set to 2.5 ms. As described above, the image sensor CC according to the focal length of the photographing lens
By determining the maximum value of the integration time of D41, it corresponds to a low-luminance subject.

As described above, in the present invention, blur detection is performed using the output of the area sensor that detects the subject image, and the above-described blur correction is performed using the detected blur amount.

Next, the interface between the interchangeable lens 4 and the camera body 32 will be described. From the interchangeable lens 4, correction magnification KBLX, KBLY (value corresponding to each focal length when zooming is performed): (amount of image movement on film surface) / (drive pulse) and focal length f _L is entered.

Then, drive pulse x _i = image movement amount X ₀ / correction magnification KBLX or yi = image movement amount Y ₀ / correction magnification K
BLY is required. Next, data necessary for performing the above-described lens driving {1 direction X: positive, negative 2 driving speed V _xi } 3 driving pulse X _i 4 driving pulse X _i ′ 5 direction Y: positive, negative 6 driving speed V _yi ◇ 7 drive pulse Y 8 drive pulse Y _i '◇ 9 return to origin ◇ is output to the lens side. Here, the origin return signal 9 is set only when the lens is returned to the origin, and the lens returns the correction lens 20 to the origin only when this signal is present.

In the control on the lens side, the correction lens 20 is driven as described above based on the input data. When undetectable data is output, the same data as the immediately preceding data is output.

Next, control of the integration time of the CCD 41 will be described. FIG. 10A is a circuit for controlling the integration time of the CCD 41, and includes an illuminance monitor SPD and a photometry circuit. The photometric circuit includes an integrating circuit and a reset circuit. The illuminance monitor SPD is formed in the vicinity of the photographing area of the CCD 41. The photocurrent output from the illuminance monitor SPD is
It is integrated by the integration circuit. The output of the integration circuit is proportional to the amount of light incident on the illuminance monitor during the integration period. The reason for using the illuminance monitor and the photometry circuit is to keep the output of the CCD 41 constant even when the subject is illuminated by an AC light source such as a fluorescent lamp. If the integration time of the CCD 41 is fixed when capturing an image of a subject under the illumination of the AC light source, the readout output fluctuates every time. CC
In order to stabilize the read output of D41, the integration time needs to be adjusted according to the illuminance of the subject. In this embodiment, the integration of the photometric circuit is started at the same time as the integration of the CCD 41 is started, and the exposure amount of the CCD 41 is monitored by the output of the integrating circuit.

FIG. 10 (B) is a modification of FIG. 10 (A).

Next, the operation of the integration time control circuit shown in FIGS. 10A and 10B when the CCD 41 is used as a blur detection sensor will be described. The reset circuit is turned on, and the integration circuit is reset. The electric charge in the accumulation section of the CCD is cleared. When integration of the CCD 41 is started, the reset circuit is turned off, and the photometric circuit starts integration.

FIG. 11 is a diagram showing a temporal change in the output of the photometric circuit. The horizontal axis t indicates the integration time, and the vertical axis I indicates the magnitude of the output of the photometric circuit. When the subject is illuminated by the AC light source, the output of the photometric circuit rises in a curve as shown in the figure. Set the photometric output to a suitable reference value I
When the photometric output I becomes I0 as compared with 0, the integration circuit is reset, and the integration of the CCD 41 is stopped. C
The output of the CD 41 is read, and it is determined whether the exposure amount is appropriate. If the exposure amount is appropriate, the reference value I0 is used for the subsequent exposure. If the exposure amount is inappropriate, for example, the exposure amount is multiplied by k to make I0 × k a new reference value I0, and subsequent exposure is performed.

FIG. 12 is a schematic diagram of a chip of the camera shake detection sensor 29.

Reference numeral 210 denotes a sensor chip, and reference numerals 211 to 214 denote pixel rows, each row having 52 pixels.

The number of pixels is 68, and the total number of pixels is 68 × 5.
2. Reference numerals 215 to 218 denote vertical transfer CCDs, 219 denotes a horizontal transfer CCD, and 220 denotes an output amplifier including a charge detection unit. Reference numeral 221 denotes an illuminance monitoring SPD which is arranged so as to surround the CCD light receiving area so that the illuminance of the CCD light receiving area can be measured as accurately as possible. 222 is a photometric circuit.

The sequence of the camera including the above-described shake detection and correction will be described with reference to the flowcharts of the main CPU and the shake correction control CPU.

First, the sequence of the main CPU 1 will be described. Referring to FIG. 13, the main CPU is in a standby state in a loop of step # 5 (hereinafter, step is abbreviated). That is, the loop of # 5 waits for the switch S1 to be turned on by the first stroke of the release button. When the switch S1 is turned on, the AF completion flag AFEF and the signal are reset (# 10), and the necessary circuits such as the photometry circuit 3, the AF detection module 13, and the camera shake correction controller 15 are turned on (# 15).
Next, an origin return signal of the correction lens 20 is output to the photographing lens 4 (# 20), and the timer is reset and started (# 25), and lens data of the photographing lens 4 is input. After the input of the lens data, a correction period TS suitable for the focal length f _L of the photographing lens 4 is determined (# 32), and open metering is performed (# 35). Note that the focal length f _L and TS
As described above, when f _L <50 mm, TS =
TS = 5m for 10ms, 50mm ≦ f _L <200mm
For s, 200 mm ≦ f _L , it is determined that TS = 2.5 ms.

At # 40, it is determined whether or not the AF completion flag AFEF is 1. If it is 1, the program jumps to # 65, and if it is not 1, the program proceeds to # 45. #
At 45, AF detection is performed. In # 50, it is determined whether or not the camera is in focus as a result of the AF detection in # 45. If the camera is in focus, the program goes to step # 55, and if not, the program branches to step # 60. In step # 60, after the photographing lens 4 is driven to the focus position, the program jumps to step # 45. In # 55, the AF completion flag AFEF is set to 1. In # 65, A is set based on the photometric value, film sensitivity obtained in # 35, and the distance information obtained as a result of AF in # 45.
An E operation is performed. In # 70, the exposure amount of the CCD 41 is set.

At step # 75, it is checked whether the switch S2 of the second stroke of the shutter button is ON. If the switch S2 is ON, the program is # 1
Go to 05, if not ON, branch to # 80. # 80
Then, it is determined whether or not the switch S1 is ON. If the switch S1 is ON, the program jumps to # 25. If it is not ON, since the shutter button has not been pressed at all, it is checked by a timer at # 85 whether a predetermined time has elapsed. If the predetermined time has passed, the power of the circuits such as the photometry circuit 3, the AF detection module 13, and the camera shake correction controller 15 is turned off (# 100), and then # 5
The program jumps to the standby state. If the fixed time has not elapsed, the AF completion flag AFEF is set to 0 (# 90), and the program proceeds to # 80.

At # 105, since the second stroke of the shutter button has been pressed, the release signal is set to the H level, and the control CPU is notified of that. # 11
After 0, the aperture of the photographing lens 4 is reduced to the aperture value obtained by the AE calculation of # 65 (# 110). The blur detection signal is H
The level is set to the level, and the shake detection sequence of the control CPU is started (# 120). The AF mirror 8 is retracted (# 125) and aperture metering is performed (# 13).
0), the shutter speed for which the AE operation has been performed is corrected (# 135).

In step # 140, the flow waits for the exposure permission signal from the control CPU to go to the H level. When the exposure permission signal becomes H level, the shutter curtain 10 is run and exposure control is performed (# 145). When the exposure is completed, an origin return signal is output to the photographing lens 4 (# 150), the correction lens 20 is returned to the origin position, the blur detection signal is set to L level, and the control CPU is notified that the exposure is completed. (# 155).

The film is wound up (# 16).
0), it is determined whether the mode is the continuous shooting mode (# 165).
If it is not the continuous shooting mode, the program branches to # 180, and if it is the continuous shooting mode, it goes to # 170 and the switch S2 is
N is determined. Here, switch S2 is OFF
If so, the program branches to # 180 since the continuous shooting mode is set but continuous shooting is not performed. If the switch S2 is ON, continuous shooting is performed, so that the blur detection signal is set to the H level (# 175), and the program jumps to # 130.

After # 180, the AF mirror 8 is returned to the detection position (# 180), the aperture of the photographing lens 4 is opened (# 185), and the release signal is set to L level (# 1).
90), the control CPU 63 is notified to that effect. Waiting for S2 to be turned off (# 205), the program jumps to # 80 and prepares for the next shooting.

Next, the operation of the control CPU will be described with reference to FIG. The power of the camera shake correction controller 15 is turned on at # 15 in FIG. 13, and the sequence is started. The flag and output signal are reset (#B
5) After the integration of the CCD 41 is reset, the integration is started (# B10). At # B30, the release signal from the main CPU is checked. If the signal is at H level, the program proceeds to # B35, and if it is at L level, the program proceeds to # B10. In step # B35, the process waits until the shake detection signal from the main CPU goes to the H level to start the shake detection.

When the shake detection signal becomes H level, the correction cycle timer is reset (# B40), and after the integration of the CCD 41 is reset, integration is started (# B42). # B4
At 5, the integration of the CCD 41 is awaited. If the integration has not been completed, it is checked in # B47 whether the integration time has exceeded TS. If it has exceeded, proceed to # B73, otherwise, proceed to # B45. After the integration of the CCD 41, the read data is dumped to the reference memory 52 and the reference memory 53 (# B50). After the count of the correction cycle timer ends (# B51), the timer is reset and started (# B52). In # B55, CCD
After the integration reset of 41, integration is started.

A contrast operation is performed (# B6
0), a block used for blur detection is selected (# B65). In # B70, the completion of the integration of the CCD 41 is awaited. If the integration has not been completed, the process proceeds to step # B72 to check whether the integration time has exceeded TS. If so, proceed to # B73; if not, #B
Proceed to 70. Step # B73 is a process performed when a sufficient exposure amount is not obtained even when the CCD integration time exceeds TS. In this step, it waits until the shake detection signal from the main CPU becomes L level. In this case, no blur correction is performed. After reaching the L level, the process proceeds to # B130.

After completion of the integration, the read data is dumped to the reference memory 53 (# B75). After the count of the correction cycle timer ends at # B76, the timer is reset and started at # B77. In # B80, the integration is started after the integration of the CCD 41 is reset.

The correlation operation (# B85) and the interpolation operation (#B
B90) is performed, and the image blur amount is detected. The lens data of the taking lens 4 is read out (# B95), and the correction amount and direction of the correction lens 20 are calculated (# B100).

At # B105, it is determined whether or not the shake detection signal from the main CPU is at the L level. If the shake detection signal is at the L level, the shake detection ends, and the program branches to # B130. If the blur detection signal is not at L level in # B105,
Since the blur detection is continued, the program proceeds to # B110.
The exposure permission signal is set to the H level (# B110) to notify the main CPU that exposure may be started, and lens correction data is output to the photographing lens 4 (# B12).
0), the program jumps to # B70. # B13
At 0, it is determined whether or not the release signal from the main CPU is at the L level. If it is at the L level, the program jumps to # B10 since the shooting has been completed. If the level is not L level, continuous shooting is performed, so the program is # B13
Proceed to 5 and wait for the detection signal to go to the H level. When the detection signal becomes H level, the program jumps to # B40.

FIG. 15 shows a camera shake detection sensor chip according to another embodiment (hereinafter referred to as a second embodiment) of the present invention. This sensor is composed of four frame interline type CCDs. One CCD will be described. 2
Reference numerals 24 to 227 denote pixel columns, which are 12 columns in total. Each column is 1
The image sensor is composed of two pixels and has 12 × 12 pixels.

Reference numerals 228 to 231 denote vertical transfer CCDs, 232
Denotes a charge storage unit. 233 is a horizontal transfer CCD, 234
Is an output amplifier including a charge detection unit. Reference numeral 235 denotes an illuminance monitor, which is arranged so as to surround the light receiving area of the CCD so that the illuminance of the light receiving area of the CCD can be accurately measured. 236 is a photometric circuit.

Since the method of blur detection is basically the same as that of the first embodiment, the different points will be described. The second embodiment has four blocks, and each block has an illuminance monitor and a photometry circuit. In the first embodiment, the blur detection is performed by selecting eight blocks from the 48 blocks. In the present embodiment, the four blocks are divided into two blocks each for the vertical direction and the horizontal direction. . Then, the correlation calculation and the interpolation calculation may be performed as in the first embodiment.

Next, a method of integral control will be described. In the first embodiment, one illuminance monitor and one photometry circuit are provided for all blocks. In this embodiment, one illuminance monitor and one photometry circuit are provided for each block. FIG. 16 is a block diagram of a camera shake detection sensor according to the second embodiment. The integration control will be briefly described with reference to FIG.
The photometric circuit of each block outputs the photometric data of each block to the integration control unit in the clock generator. Each time the integration of each block is completed based on the photometric data, the integration control unit converts the pixel data of the block into an A / D signal.
Convert and transfer to the appropriate part of memory. The integration control unit also shifts the charge accumulated in the pixel to the CCD transfer unit,
A pulse (shift pulse) for terminating the integration is output. This shift pulse can be input to each block independently. This is to end the integration even during transfer of another block. In addition, charge transfer and pixel data output can be performed only for a desired block by the block selection signal and the multiplexer. The photometry reset is performed simultaneously for all blocks.

As described above, in the second embodiment, the detection sensor is divided into four blocks, and integral control is performed independently of each other. Therefore, more suitable integration control can be performed for each block.

Note that both the first and second embodiments have described the cameras whose lenses are interchangeable. The present invention is not limited to cameras with interchangeable lenses, but can also be applied to cameras without interchangeable lenses. More specifically, in a camera having a lens with a variable focal length, that is, a so-called zoom lens, the focal length of the lens may be detected as needed, and the repetition period of blur detection / correction may be determined based on the focal length information. .

[0129]

As described above, the camera of the present invention detects and compensates for blur based on the focal length information of the photographing optical system.
A positive period is determined. Therefore, blur detection / correction is performed at a cycle suitable for the focal length. Thereby, even if the focal length is long, it is possible to prevent the blur correction error from becoming large, and to perform more accurate blur correction. Further, in the case of using an image sensor for blur detection, the maximum value of the integration time of the image sensor is changed according to the focal length of the imaging optical system. The length can be lengthened, and blur detection can be performed even on a low-luminance subject.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of a camera according to the present invention.

FIG. 2 is a sectional view showing an optical system of the camera of the present invention.

FIG. 3 is a view showing a finder screen of the camera of the present invention.

FIG. 4 is a block diagram illustrating the contents of a camera shake detection and correction unit.

FIG. 5 is a schematic diagram of a part of a light receiving section of a CCD.

FIG. 6 is a graph showing the distribution of correlation values by contour lines.

FIG. 7 is a graph showing a calculation method of an interpolation calculation.

FIG. 8 is a graph showing a calculation method of an interpolation calculation.

FIG. 9 is a graph showing a driving state of a correction lens.

FIG. 10 is a circuit diagram of a circuit for controlling an integration time.

FIG. 11 is a graph showing a temporal change of a photometric circuit output.

FIG. 12 is a schematic view of a chip of a camera shake detection sensor.

FIG. 13 is a flowchart showing an operation order of the main CPU.

FIG. 14 is a flowchart showing an operation sequence of a control CPU.

FIG. 15 is a schematic view of a tip of a camera shake detection sensor according to another embodiment.

FIG. 16 is a block diagram of a camera shake detection sensor according to another embodiment.

FIG. 17 is a diagram illustrating a relationship between a focal length of a photographing lens and blur.

FIG. 18 is a graph showing a blurred state when an image on a film surface vibrates sinusoidally.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main CPU 7 Photographing lens circuit 12 Camera shake detection correction means 20 Camera shake correction lens 21 Camera shake correction lens driving device 29 Camera shake detection sensor 41 CCD 55 Computing unit 63 Control CPU 210 Camera shake detection sensor chip

Continuation of the front page (56) References JP-A-3-87716 (JP, A) JP-A-3-91728 (JP, A) JP-A-3-200229 (JP, A) JP-A-61-145971 (JP) JP-A-4-352575 (JP, A) JP-A-62-182728 (JP, A) JP-A-2-103023 (JP, A) JP-A-3-3571 (JP, A) JP-A-3-83459 (JP, A) JP-A-3-95533 (JP, A) JP-A-4-81079 (JP, A) JP-A-4-86162 (JP, A) JP-A-4-163534 (JP, A) A) JP-A-4-212940 (JP, A) JP-A-5-40291 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B ^7/ 28-7/40 H04N 5 / 222-5/257

Claims (4)

(57) [Claims] An image sensor for capturing an image of a subject, a calculating means for calculating blur data of the subject image based on image data output from the image sensor, and a camera based on the blur data calculated by the calculating means. A blur correcting unit that performs blur correction by driving a part of the photographing optical system, an input unit that inputs focal length information of the photographing optical system, and a determining unit that determines a cycle of blur correction based on the focal length information. has the determination unit, the focal length is longer blur of the imaging optical system
Shorten the correction cycle, and the shorter the focal length,
A camera capable of detecting and correcting blurring, characterized by extending the period . 2. An image sensor for capturing an image of a subject, an arithmetic unit for calculating blur data of the subject image based on image data output by the image sensor, and an input unit for inputting focal length information of an imaging optical system; Determining means for determining a blur detection cycle based on the focal length information , wherein the determining means determines that the longer the focal length of the photographing optical system, the greater the blur.
The detection cycle is shortened.
A camera capable of detecting blurring, characterized by extending the period . 3. Further, claim 2, further comprising a shake correction means for driving a part of the camera of the imaging optical system performs blur correction based on the shake of the data calculated by said calculation means A camera that can detect the blur described. 4. An image sensor for capturing an image of a subject, computing means for computing blur data of the subject image based on image data output by the image sensor, and input means for inputting focal length information of a photographing optical system; wherein and a changing means for changing the maximum value of the integration time of the image sensor based on the focal length information, said changing means, the longer the focal length of the photographing optical system
The maximum value of the integration time small illusion, the shorter the focal length
A camera capable of detecting blur, characterized by increasing the maximum value of the integration time .