JP2903576B2 - Camera with image stabilization function - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera with a blur correction function for correcting blur of a subject image caused by camera shake or camera shake.

[Related Technology] In recent years, cameras capable of correcting camera shake have been proposed. In such a camera, the amount of blur of the subject image on the film is corrected during the exposure of the film. In order to correct the blur amount of the object on the film, the correction is performed by driving a blur correction lens provided in the lens at a speed to be corrected.

[Problem to be Solved by the Invention] In a camera capable of correcting camera shake, camera shake has been corrected as described above. However, there are cases where the speed of the correction lens for performing the camera shake correction is too fast to perform the correction compared to the performance of the camera shake correction means, or where the correction amount is too large and the correction amount is insufficient. Conceivable. In such a case, even if the camera has the correction means, the camera shake cannot be corrected completely, and a problem occurs in which a photograph with the camera shake is taken.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a camera with a blur correction function that can correct the blur of a subject image as much as possible.

[Means for Solving the Problems] A camera with a shake correction function according to the present invention includes: a shake detection unit that detects a shake amount of a subject image on an image forming plane of a photographing optical system; A shake correction unit that corrects a shake of the subject image by driving an optical element that forms at least a part of a photographing optical system, and a determination unit that determines whether the shake correction unit can correct the shake correctly And control means for operating the determination means during an exposure period.

[Operation] According to the present invention, it is determined whether or not the blur correcting unit that corrects the blur of the subject image by driving the optical element that forms at least a part of the photographing optical system can correct the blur. Further, the determining means is operated by the control means during the exposure period.

FIG. 1 is a perspective view conceptually showing the structure of a camera as one embodiment of the present invention. The camera body 11 has an angular velocity sensor for detecting angular velocities in a pitching direction and a rolling direction in a plane (xy plane in the figure) perpendicular to an optical axis (z axis in the figure) of the photographing lens 12. Sx and Sy are built-in.

FIG. 2 is a block circuit diagram showing a control relationship of the camera shown in FIG. Referring to FIG. 2, the camera according to the present invention includes a microcomputer (hereinafter referred to as "microcomputer") μC for performing a sequence of the entire camera, exposure calculation, and exposure control. The microcomputer μC is connected to peripheral circuits CT ₁ and CT ₂ , which will be described in detail later, switches for controlling the operation of the camera, and a power supply for supplying power to the microcomputer and the peripheral circuits CT ₁ and CT ₂ . .

The peripheral circuit CT ₁ measures the brightness of the subject, converts it into a digital signal, and transmits it to the microcomputer μC. The peripheral circuit CT ₁ converts the analog signal indicating the distance output from the distance detection circuit into a digital signal. a distance measuring circuit MD for outputting to the μC, a lens driving circuit LD for driving a focus adjusting lens based on the distance obtained based on the data of the distance measuring circuit MD, and a diaphragm / shutter; An exposure control circuit AE that controls the shutter based on the shutter speed determined based on the LM output and automatically controls the aperture, and the film sensitivity recorded on the film cartridge
Reads S _V, and a film sensitivity reading circuit ISO for transmitting to the microcomputer [mu] C.

The peripheral circuit CT ₂ detects the angular velocity of the camera in the pitching direction and the rolling direction, receives the angular velocity sensors Sx and Sy that transmit the blur amount to the microcomputer μC, and receives the output from the microcomputer μC to correct the blur. And a blur correction lens control circuit Cxy for driving a lens Lc for driving the lens Lc in a plane perpendicular to the optical axis.
The camera shake correction lens control circuit Cxy
By outputting a correction signal to x and Cy, camera shake is corrected.

The microcomputer μC further includes a display circuit DISP for warning blurring, a zoom encoder ZEN for transmitting the focal length of the photographing lens 12 as a zoom lens to the microcomputer μC,
It includes a flash circuit FL that emits flash light, and an aperture encoder AVEN that transmits an aperture value to the microcomputer μC.

Next, switches will be described. The switches connected to the microcomputer μC include a main switch SM that turns on the camera when ON and a drive stop state when OFF, and a shooting preparation switch S1 that is turned on with the first stroke of a release button (not shown). And an exposure start switch SST that is turned on when the shutter is started and exposure is started, with the release switch S2 being turned on by the second stroke of the release button. When the shooting preparation switch S1 is turned on, a shooting preparation operation such as a photometry operation or a distance measurement is performed. When the release switch S2 is turned on, exposure control is performed.

Next, the power supply will be described. Direct output voltage V0 of the power source battery E, the flash circuit FL and the first, are supplied to the peripheral circuits CT _1, CT ₂ via the second feed transistors Tr1, Tr2. The backup capacitor C1 is charged by the power supply battery E via the backflow prevention diode D1. Charge voltage VDD of capacitor C1 for backup
Are supplied to the microcomputer μC, the display circuit DISP, the zoom encoder ZEN, and the aperture encoder AVEN. The above-described peripheral circuits CT ₁ and CT ₂ include circuits with large power consumption, and the voltage of the power supply battery E may temporarily drop during driving. Even when the voltage drops, the microcomputer μC operates normally because it is supplied with power from the backup capacitor C1.

This concludes the description of the hardware configuration of the present embodiment. Next, a software configuration of the present embodiment will be described.

FIG. 3 shows an interrupt SMI executed when the main switch SM is operated to switch from OFF to ON or from ON to OFF.
6 is a flowchart showing the contents of NT. This interrupt SMIN
When T occurs, it is first determined whether or not the main switch SM is ON (# 5). If the main switch SM is OFF,
It is determined that the main switch SM has been operated from ON to OFF. As a result, the boosting of the flash circuit FL is stopped, the first power supply transistor Tr1 is turned OFF, supply of power to the first peripheral circuit CT ₁ comprising light measuring circuit LM or the like is stopped. Then the second
The power supply transistor Tr2 is turned off, and the angular velocity sensors Sx, S
The power supply to the _second peripheral circuit CT2 including y is stopped. The display is erased, and the microcomputer μC enters the halt state (# 65).
~ # 75). If the main stitch SM is ON in # 5, all the flags are reset, the boosting of the flash circuit is started, and the capacitor of the flash circuit FL (not shown)
Start charging. Then ON the power supply transistor Tr2, the angular velocity sensor Sx, and starts to supply power to the second peripheral circuit CT ₂ comprising Sy, the timer T ₁ resets and starts (#
10 to # 20). Here, the timer T ₁ is a holding timer for performing feed hold to the peripheral circuit CT _1, CT _2. next#
At 25, it is determined whether or not the shooting preparation switch S1 is ON. If it is ON, the subroutine of S1ON is executed at # 30, and the program returns to # 25.

FIG. 4 is a flowchart showing a subroutine of S1ON. When the photographing preparation switch S1 is turned on, the boosting of the flash circuit FL is stopped (# 100). Switch S1 is O
It is determined whether or not the flag S1offF indicating that the holding time (10 s) has elapsed has been set (# 10).
5), if it is set, which was reset to ON the transistor Tr2, the program proceeds to step # 125 to reset and started the power holding timer T ₁ (# 110 to #
120).

When the flag S1offF is not set in step # 105, the program immediately proceeds to # 125, and the peripheral circuit CT ₁
The transistor Tr1 is turned on to supply power to the power supply, and photometry data and distance measurement data are input (# 125 to # 135).

Next, the subroutine of the photometric circuit LM will be described with reference to FIG. Brightness value B _V from the photometric circuit LM is, the film sensitivity reading circuit ISO is film speed S _V read. Exposure value E _V = B
_V + S exposure time T _EV from the exposure value E _V obtained in _V is required, the program returns (# 205 to # 220).

Returning to FIG. 4, next, the focal length f is read from the zoom encoder ZEN (# 140), the flag FLF indicating the flash emission is reset (# 150), and whether or not the charging of the flash circuit FL is completed. Is detected (# 160). If the charging of the flash circuit FL is not completed (when the potential of the terminal CHC shown in FIG. 2 is H), the program proceeds to step # 165, and the boosting of the flash circuit FL is started. Specifically, the potential of the terminal STA is set to H (# 165).
Next, if there is a blur warning in step # 170, the warning display of camera shake is erased and the program returns to # 160 (# 170,
# 175). Here, when the flash circuit FL is boosted, the warning display disappears because the voltage of the battery tends to fluctuate during the boosting, and the data indicating the amount of blur is not accurate.
This is because the shake amount is not calculated. Step # 160
When the charging of the flash circuit FL is completed (when the potential of the terminal CHC is L), the boosting of the flash circuit FL is stopped (the potential of the terminal FTA is set to L) and the release switch S2 is turned on.
It is determined whether N has been performed (# 180, # 185). If the release switch S2 is ON, exposure control is performed, and the program returns (# 185, # 190). Step # 185
When the switch S2 is not ON, it is determined whether or not the switch S1 is ON.If the switch S1 is OFF,
The program returns (# 195). If the switch S1 is ON in step # 195, the shake amount is calculated, displayed, and the program returns to step # 160 (# 195 to #
205).

Referring to FIG. 6, a description will be given of a subroutine of the shake amount calculation indicated by # 200 in FIG. First, angular velocities (blur data) ΔVx and ΔVy are input from the angular velocity sensors Sx and Sy, respectively (# 250). The previous angular velocity Bx is set to LBx, and the angular velocity ΔBx in the x direction on the image plane is calculated in consideration of the focal length f, and the flag BLx indicating that the angular velocity (blur amount) in the x direction is large is reset (# 255). ~ # 265).

The reason why the angular velocity (blurring data) is determined in consideration of the focal length is that the image blur amount changes depending on the focal length, and the blur amount increases as the focal length increases.

Next, the calculation of the shake amount will be described in detail. Output from angular velocity sensors Sx, Sy (electric charge amount converted to voltage)
Is the angular velocity obtained from Where the angular velocity sensor Sx,
If the blur amount detected by Sy is represented by B, then B =

The image blur amount Δu on the film equivalent surface is a function of the focal length f of the photographing lens 12 at that time, and is a function of the tangent of the blur angle θ. Therefore, Δu = f · tan θ... And Δu = f · tan (∫dt). Here, if the image speed on the film surface is FB, Becomes The speed UB that moves the correction lens for blur correction is
There is a constant relationship with the image blurring speed u, and if a constant is a, Becomes

By the way, this dU / dt has a limit that can be moved.
_Let it be B _K. Also, the speed UBx to be moved by the correction lens calculated from the obtained angular velocity is Here, the subscript x indicates a value in the x direction. It is determined whether the speed UBx at which the correction lens should be moved for the shake correction is within the limit speed UB _K at which the correction lens can be moved, in other words, whether the obtained speed to be corrected is within the range that can be corrected is the sixth. This is performed at # 285 in the figure.

Note a speed UB = a · FB moving the correcting lens, a relationship of UBx = a · FBx UBy = a · FBy UB K = a · FB K. That is, the determination at # 285 is | FBx | ≧ FB _K
This is synonymous with the determination of whether or not.

Since the image blur amount is obtained by the product of the speed and the time, the time will be considered next. Generally, it is assumed that an exposure time _TEV is required for photographing. On the other hand, consider the correction possible time T _K. The correctable time T _K is defined as a maximum speed UB _{K at} which a correctable movement amount in one direction can be corrected.

Returning to # 285 of FIG. 6, when the speed UBx be moved with the x-direction of the correction lens is determined to be rate UB _K than can be corrected, the program proceeds to # 290, the exposure time T
_EV whether greater than correctable time T _K is determined.

Next, consider the image blur amount BLx that cannot be corrected. Limiting speed UB _{K of} correction lens and speed UBx to be moved
The image blur amount on the film surface is represented by FB _K and FBx. In this case, if the exposure time T _EV ≥ the correctable time T _K , the uncorrectable image blur amount BLx = (| FBx | −FB _K ) · T _K + | UBx | · (T _EV −T _K ), and T _EV if _{<T K, BLx = (|} FBx | -FB K) · T program as _EV proceeds to # 330.

FIG. 7 is a diagram showing a lens optical system of the camera with shake correction according to the present invention. An optical system according to the present invention will be described with reference to FIG. An optical system of a shake correction camera according to the present invention includes an AF lens AFL driven by an AF motor for focusing, and a lens group including a correction lens Lc that moves vertically to an optical axis for blur correction. In response to the output B of the angular velocity sensor Sx (only the x direction is considered here), the correction lens Lc moves the velocity UB in the direction of the arrow in the figure.
It is moved by. When the correction lens Lc is moved in the direction of the arrow in the drawing at the speed of UB, the image moves on the film surface FP at the speed of FB. The AF motor is arranged near the camera body 11 where the angular velocity sensor Sx is arranged, rather than near the lens optical system.

FIG. 8 is a flowchart showing the outline of the method of blur correction according to the present invention. First, the image blur amount is calculated (#
900), the moving speed UBx and exposure time T _EV and correctable time T _K to be corrected in the correction lens Lc shown in FIG. 7 is calculated (# 905). Next, it is determined whether or not there is a lens that can move at a speed necessary for correcting the correction lens Lc based on the above calculation result (# 910). Specifically whether correction lens speedy UBx be moved is smaller than the limit speed UB _K of the correction lens is determined. The speed UBx at which the correction lens LC should be moved at # 910 is the limit speed UB _K
If it is determined to be smaller than
To advances, the exposure time T _EV whether exceeds the allowable exposure time T _K is determined (# 915). Exposure time T _{EV in} step # 915
Is determined not to exceed the allowable exposure time T _K , there is no problem in terms of the moving speed for the correction of the correction lens Lc and the exposure time.
925). In contrast, in the case of exceeding the exposure time T _EV permissible exposure time T _K step # 915, the follow-up for the exposure time to shake correction becomes impossible. This case corresponds to case III described later with reference to FIG. 9C.

Speed U to move correction lens LC in step # 910
# 915 when Bx exceeds the limit speed UBk of the correction lens
Then, it is determined whether the exposure time _TEV exceeds the allowable exposure time T _K (# 920). If it is determined in # 920 that the exposure time T _EV exceeds the allowable exposure time T _K , it corresponds to the case II described in FIG. 9B, and the exposure time T _EV does not exceed the allowable exposure time T _K. Contains the case I described in FIG. 9A.
Corresponds to the case. In any case, in these cases, the blur correction cannot be followed (# 930).

Next, a description will be given below of a case where the blur correction following described in the cases I to III described above is impossible.

9A to 9C are diagrams for illustrating the blur correction ineligible regions in cases corresponding to the cases I to III in which the blur correction inequality described in step # 830 of FIG. 8 is impossible. In each figure, the horizontal axis represents time, and the vertical axis represents the image speed on the film surface. Therefore, the area represented on the XY plane represents the distance, that is, the blur amount or the like.

In the case of FIG. 9A, as described in step # 930 of FIG. 8, UBx ≧ UB _K and T _EV <T _K. 9A to 9C, the moving speed UB of the correction lens Lc is different from that in FIG.
It is expressed using the film speed FBx instead of x, etc., but since a proportional relationship is established between them from the relationship shown in FIG. 7, in FIGS. 9A to 9C, the film This will be described using the image speed FBx on the surface.

In FIG. 9A, as described above, the image speed FBx on the film surface is different from the image speed | FBx | −
Since it exceeds FB _K , | FBx | −FB _K is the shake amount per unit time. The image blur amount is obtained by multiplying this by the exposure time _TEV , that is, the portion shown by oblique lines in FIG. 9A. Here, the blur amount | Bx | detected by the angular velocity sensor is assumed to be constant.

FIG. 9B is an image rate FBx on the film surface of the image on the film surface can be corrected speed FB _K a beyond which and the exposure time T _EV
It is a diagram of a case where even exceeds the correctable time T _K. Similarly to FIG. 9A, also in this case, the shaded portion is the image blur amount that cannot be corrected. Therefore, in this case, the amount of image blur cannot be corrected to (| FBx | −FB _K ) · T _K (T _EV −T
_K ) is multiplied by the shake amount FBx per unit time, that is, the amount obtained by adding | FBx | · (T _EV −T _K ).

FIG. 9C is an image rate FBx are correctable limit velocity FB _K from the image kinetically on small for the film surface also can follow the image blur but the exposure time T _EV capable correction time T on the film surface
It is the case where it exceeds _K. In this case, the margin in the image speed on the film surface, that is, (FB _K − | FBx
|) · T _K part of the shake amount of exposure time side allowance for blurring represented by is canceled.

As described above, the amount of blur that cannot be corrected is calculated. The value is determined by steps # 295, # 305, and # 315 in FIG.
And # 320 as BLx. In FIG. 6, Steps # 285 to # 320 correspond to Steps # 285 to # 320 in FIG.
The description is omitted because it is the same as 910 to # 930. After these values have been determined, the program proceeds to # 330,
It is determined whether or not the blur amount BLx that cannot be corrected as described above exceeds the allowable blur amount BL _K (a blur-acceptable amount on a photograph). Uncorrectable blur BLx is allowable blur B
If L _K is exceeded, flag BLxF is set and the program proceeds to step # 345. On the other hand, this value is the allowable blur amount B
If L _K or less, the program goes directly to # 345 (# 3
30 to # 340).

In the following steps # 345 to # 415, since the shake amount obtained in the x direction is obtained only in the y direction, the description thereof will be omitted.

Next, in step # 420, the magnitudes of the absolute values of the shake amounts detected by the angular velocity sensors in the x direction and the y direction are compared. This comparison is made between the x direction and the y direction.
This is because it is sufficient to consider the larger of the directions as the blur amount. Therefore, in # 440 to # 450, it is determined that the shake amount in the y direction is larger than the shake amount in the x direction,
The blur amount BLy in the y direction is substituted for BL. # 425 to # 43
In 5, the deviation amount Bx in the x direction is larger than the deviation amount B in the y direction.
Judgment is larger than y, and the blur amount BLx
And the program returns.

FIG. 10 shows a display subroutine shown in step # 205 of FIG. Referring to FIG. 10, if either of the flags BLxF and BLyF indicating that the shake amounts in the x and y directions are large is set, a shake warning is issued,
When both are not set, the program returns without warning of blur (# 430 to # 445).

Next, returning to FIG. 8 again, the case in which the shake correction tracking cannot be performed, that is, the case I to the case III shown in FIGS. 9A to 9C.
The treatment in the case of is described. Even in such a case, it is necessary to take some measures to reduce the blur amount. Therefore, in the present invention, in such a case, the exposure time is reduced to reduce the blur amount (# 845). That is, for example, as shown in FIG. 9A,
The area indicated by the hatched portion corresponds to the blur amount. In order to reduce the blur amount, it is necessary to reduce the area of the hatched portion. However, it is not possible to correct the blurring amount by reducing the size of FBx-FB _K by increasing the image rate FB _K on the film surface. because,
FB _K is because it is critical image speed on the film surface.

Therefore, in order to reduce the area of the shaded area, the exposure time T
You can see that the _EV should be shifted to the left. That is, the amount of blur can be reduced by reducing the exposure time.

However, simply reducing the exposure time cannot provide a sufficient exposure. Therefore, in the present invention, when the exposure time is reduced, the reduced exposure time is compensated for by the flash emission (# 95).
0). Thereafter, photography is performed according to a normal routine (# 935).

Next, regarding the exposure control flow that takes into account the idea of reducing the exposure time to reduce the
This will be described with reference to FIGS. First, in exposure control, AF control is performed (# 500). After the completion of the AF control, the shake amount calculation is performed (# 505,
# 510). The calculation of the amount of shake (input of shake data ΔVx, ΔVy) after AF is completed is performed for the following reason. That is, while the lens is being driven, the vibration of the motor and the vibration by the driving mechanism occur. This is the blur amount (angular velocity). This is because if blur correction is performed using data that is not a blur amount actually caused by a photographer's operation as data, erroneous correction will be performed during exposure.

Next, it is determined whether or not a flag indicating that the amount of shake in each of the x and y directions is large is set. If neither is set, the program proceeds to # 570 (# 515, # 520). If one of the flags BLxF and BLyF is set, the program proceeds to step # 525.
To calculate the exposure time TA. The exposure time TA corresponds to the exposure time reduced to reduce blurring amount previously mentioned, determined by dividing the amount of shake exceeds the allowable amount BL _K at an angular velocity (vibration amount per unit time) at that time Can be

Next, a flowchart for calculating the exposure time TA for reducing the blur amount will be described with reference to FIG. First image rate on the film surface | FB | whether or limit image speed FB _K on a given film surface is determined (# 526).
If | FB | <FB _K in # 526, the absolute value of the blur amount (at this time, the exposure time T _EV > the correctable time T _K is satisfied, and | FB | · (T _EV −
From T _K) is blurring amount BL), pull the allowable value BL _K, which image blur amount | FB | in the split, the exposure time to reduce the blurring amount
TA is required (# 535).

FB | | image rate on the film surface with a # 526 when the above limit speed FB _K on the film surface, it is determined whether T _EV ≧ T _K, if T _EV <T _K, blurring the amount | BL | minus the tolerance BL _K from (| BL | -BL _K) an image blur amount | FB | from correctable speed F
The exposure time TA for reducing the blur amount is obtained by dividing by the value obtained by subtracting B _K (| FB | −FB _K ) (# 527, # 537). # 52
If T _EV ≧ T _K in step 7, the blur amount {| BL | − | FB | · (T _EV −T _K )} on the image plane has already reached the allowable value BL _K until the exposure time T _K in step # 530. It is determined whether it has exceeded (# 530). Step If it is determined that exceeds the allowable value BL _K is # 530, it is necessary to end the exposure at a time before the exposure time T _K, the shake amount to the exposure time T _K {| BL | -BL _K − | FB | · (T
_EV− T _K )｝ is the exposure time TA obtained by adding the time from T _{K to} T _EV to the allowable value. On the other hand, in step # 530
When BL | − | FB | · (T _EV −T _K )｝ ≦ BL _K , a part of the shift amount between T _{K and} T _EV may be cut, and | BL | − | FB | · TA = BL
From _{K TA = (| BL | -BL} K) / | FB | seeking exposure time TA by the program returns after the process of step # 538 or # 532.

Returning to FIG. 11A, after calculating the TA at # 525, as described above, set the exposure to an underexposure so as to reduce the amount of blur as much as possible, and fire the flash to compensate for the insufficient exposure. Perform In # 540, a flag FLF indicating this is set. Exposure compensation amount ΔE from exposure time _TEV and TA
_{Find V.} This in exposure time T _EV (E _V is obtained) is obtained, the exposure correction amount Delta] E _V knowing the exposure time TA from the relative relationship between the values in order to understand naturally (# 540,
# 545). Whether the exposure compensation amount ΔE _V is 2E _V or more is # 550.
Is determined. If Delta] E _V is 2E _V or more, a Delta] E _V and 2 in consideration of the latitude of the film, at # 550 Delta] E _V is 2E _V
If it is less than 1, proceed to # 560. Exposure value E _V is E _V = E _V
+ Is a Delta] E _V, based on this correction value, the program calculates the aperture value A _VD when the flash issue gain exposure amount to be corrected, the process proceeds to step # 570 (# 560 to # 565). Although provided a limit of 2 to a value of Delta] E _V, if the read latitude from the film container, the latitude to carry out the judgment of # 550 in place of the 2 desired.

Next, the program starts the aperture value calculation subroutine (# 565)
The contents will be described with reference to FIG. In the aperture value calculation subroutine, first, the value of the aperture value _AVD is set to I
_V (light emission amount) + S _V (film sensitivity) -D _V (distance) -ΔE _V
(# 805). The aperture at that time from the obtained exposure amount E _V (since the present invention is the camera aperture-shutter method applied, the shutter speed similarly uniquely aperture from the exposure value is obtained) is obtained. A comparison is made between the aperture value AV and the aperture value _AVD for flash emission obtained above (# 810, # 815). If AV> A _VD at # 815,
Let AV be the control aperture value _AVC and control aperture value A if AV ≤ _{AVD
VC is set} to _AVD , the aperture value is reduced, and the program returns (# 815 to # 825).

Referring to FIG. 11B, the flow after step # 570 will be described. The correction data Bx and By are output to the correction circuit Cxy,
Again exposure time T _EV from the exposure value E _V obtained is determined (# 5
70, # 575). In the repeated flow from the start of exposure,
Reset the variable LT _E indicating the exposure time elapsed up to the previous time,
Is the variable [Delta] BL ₁ 0 of the previous shift amount, the exposure time T _EV is output to the exposure control circuit AE, then the exposure start signal is output to the exposure control circuit AE (# 570~ # 590). As a result, the exposure control mechanism operates, and the shutter is driven. Next, the shake amount is calculated again, the correction data Bx and By are output, and the shake amount is corrected even during the release time lag period (# 595, # 6).
00). And exposed on the film surface is started is detected by the switch SST is turned on, the start timer T _E indicating the exposure elapsed time if ON, the blur amount calculation to perform again shake correction And the correction data Bx,
By is output (# 615, # 620). From step # 615, depending on the exposure time _TEV , if the _TEV is long, the shake amount calculation is repeated a plurality of times. To obtain a time [Delta] T _E to perform this flow once to the current from the previous, obtaining the [Delta] T _E in T _E -LT _E. The current exposure time _TE is LT _E (# 625, # 63
0). Shake amount ΔBL due to changes of the vibration velocity could not be corrected occurs during this time [Delta] T _E is determined as _{ΔT E × (FB-FLB)} · 1/2. The current shake amount ΔBL is added to the previous shake amount to newly set to ΔBL ₁ (# 650, # 655). ΔBL = ΔT
_E × (FB−FLB) · 1/2 is multiplied by 1/2 because the amount of shake occurring at that time is calculated assuming that the speed changes gradually. Then obtains a remaining time T ₂ of the exposure to the end at T _EV -T _E, predicts the amount of shake occurring during this time (the amount that can not be corrected) (# 660). First shake speed FB on the film surface is determined whether correctable maximum speed FB _K or more, if FB ≧ FB _K, the exposure time T _EV is correctable time T _K
It is determined whether or not this is the case (# 665, # 670). T _EV ≧ at # 670
If it is not T _K , it is assumed that the blurring prediction amount ΔBL ₂ = (FB−FB _K ) × T ₂ (# 675). If T _EV ≧ T _K in # 670, the blurring prediction amount ΔB
The program proceeds to step # 700 as L ₂ = (FB−FB _K ) · T ₂ + FB · (T _EV −T _K ). If FB <FB _K at # 665,
_{(FB K - | FB |)} · T K / FB + T K seek T _K 1 from whether T _EV ≧ T _K1 is determined (# 667, # 685). T in step # 685
_{If EV} ≧ T _K , the blur prediction amount ΔBL ₂ = FB · (T _EV −T _K ). If T _EV <T _K , the blur amount ΔBL ₂ = 0 and the program proceeds to step # 700 (# 685 to # 695).

Next, the uncorrectable blur region | ΔBL ₁ | and the predicted blur amount ΔBL ₂ are added to obtain ΔBL ₃ , which is an allowable predetermined value BL _K
It is determined whether or not this is the case (# 700, # 705). Thus determine the [Delta] BL ₃ and has been subjected to exposure compensation when the blurring amount is large, the actual blurring amount and the expected shake amount is to perform a correction of the exposure compensation at different times. And if ΔBL a ₃ ≧ BL _K at # 705, the program steps # 7
Proceed to 10, and if ΔBL ₃ <ΔBL _K , the program proceeds to # 795
Proceed to.

The flow after step # 710 will be described with reference to FIG. 11C. If at # 705 [Delta] BL is ₃ ≧ BL _K, but it should perform control to shorten the further exposure time, the more the correction if the correction amount Delta] E _V in the step # 710 is over 2 performed If not, the program proceeds to # 770. If Delta] E _V <2 at step # 710, pull the actual blurring amount [Delta] BL ₃ from the allowable predetermined amount BL _K, the difference ΔB'L determined, determine the T _A This divided by blurring rate FB of the time (# 715, # 7
20). Then, the exposure compensation amount ΔE _V 2 is obtained from the exposure time _TEV and TA.
Is determined, and it is determined whether or not the amount obtained by adding the above-described ΔE _V 2 to the exposure correction amount ΔE _V is 2 or more (# 730). Step # 7
If this is 2 or more at 30, ΔE _V 2 = 2−ΔE _V (# 7
35) If less than 2, the program proceeds to step # 735
Is skipped, and the program proceeds to step # 740 (# 735).

At step # 740, and _{E V = E V + ΔE V} 2, again obtains the T _EV future exposure time, and T _EV = T _EV -T _2, and outputs the _{T EV (# 740~ # 755)} . The flag FLF indicating the flash emission is set, the aperture value _AVD is calculated, and the program proceeds to step # 7.
Go to 70. In step # 770, it is determined whether or not the shutter closing signal has been output from the exposure control circuit AE (the shutter closing operation has already been performed). If the shutter closing signal has not been output, the program proceeds to step # 615.
Only, execute the flow from there. When the microcomputer μC is inputting the close signal, the program proceeds to step # 775 to determine whether or not the flag FLF is set (# 775). When the flag FLF is set in step # 775, the absolute aperture value AV is input, and AV ≧ A
_It is determined whether or not _VC , and if AV <A _VC , the program returns to step # 780 (# 780, # 785). On the other hand, if AV ≧ A _VC in step # 785, a flash light emission signal (terminal EM
1) is output to the flash circuit FL to cause flash emission, and the program returns (# 785, # 790).
If the flag FLF is not set in # 775, the program returns immediately.

If [Delta] BL ₃ <BL _K at step # 705, the program proceeds to step # 795 (No. 11C view), first correction exposure amount Delta] E _V
Is determined to be 0, and if it is 0, the program proceeds to step # 770 (# 795). Step # 795 at unless Delta] E _V is 0, pull the permissible correction amount BL _K from blurring amount [Delta] BL _3,
This is divided by the shake speed FB at that time to determine the exposure time TA (# 775 to # 805). Next, an exposure correction amount ΔE _V 2 (> 0) is obtained from the exposure times T _EV and TA (# 810). Then compared with the exposure correction amount Delta] E _V and the Delta] E _V 2 up to the last time, if ΔE _V ≧ ΔE _V 2, the program proceeds to step # 830. If ΔE _V <ΔE _V 2 in step # 815, ΔE _V → ΔE _V 2 so as to set the exposure correction amount to 0, the flash light emission flag FLF is reset, and the program proceeds to step # 830 (# 815 to # 815). #
825). Then, the program with ΔE _V = −ΔE _V 2 proceeds to step # 740 (# 830).

14A and 14B are diagrams showing the relationship between the opening and closing of the shutter and time. FIG. 14A is a diagram showing a case where normal blur correction is performed, and FIG. 14B is a diagram showing a state where the present invention is applied. In each of the figures, the area of the trapezoidal portion represents the appropriate exposure amount when the stationary light is used. If normal blur correction is performed with reference to FIG. 14A, the time from the point M at which it is detected that blur correction cannot be performed to the time when the shutter closes, that is, the blur correction catches up in the region represented by OVB Absent. as a result,
Blur occurs.

If the blur correction according to the present invention is performed with reference to FIG. 14B, the exposure amount is recalculated at the time M when the blur correction is impossible, the exposure time TA is obtained, and the flash is fired if necessary. Move to control. Here, the control is performed by flashmatic. As shown in the figure, the aperture is started to close, and at the time indicated by N, a flash is fired to reduce the blur amount.

By performing such control, according to the present invention, compared with the case where the flash is fired from the beginning,
As much light as possible is used as the stationary light, so you can take good pictures with depth.

Returning to FIG. 3, if the photographing preparation switch S1 is OFF in step # 30, it is determined whether or not charging is completed. If charging is completed, boosting is stopped. Step # 40
Powered by holding timer T ₁ is determined whether the counting of 10 seconds. If the timer T ₁ is not counted 10 seconds, the program proceeds to # 30, to perform the determination of S10N. Timer T _{1 in} # 40
If it is measuring 10 seconds, feed transistor Tr1 at # 45
To turn off the power supply to the _first peripheral circuit CT1 including the photometric circuit LM and the like. Power supply transistor in step # 50
Tr2 is turned off, the power supply to the _second peripheral circuit CT2 including the angular velocity sensors Sx and Sy is stopped, and all the display by the display circuit DISP is erased in # 55. Then, in step # 60, a flag S1offF indicating that the shooting preparation switch S1 is OFF.
Is set, and the program executes the flow from # 10.

[Effects of the Invention] As described above, according to the present invention, it is determined whether or not the blur correction unit that corrects the blur of the subject image by driving the optical element that forms a part of the photographing optical system can correct the blur correctly. Can be determined. Therefore, the camera can perform various corresponding operations based on the determination result. For example, if it is determined that the blur is not correctly corrected, the blur can be reduced by shortening the exposure time. At this time, by emitting the flash light, the reduced exposure amount can be compensated for by shortening the exposure time. Furthermore, instead of emitting the flash from the beginning to prevent image blur, the flash is emitted in response to the determination result that the correction is not performed correctly, so natural light can be used as much as possible, and the photo has depth and depth It has the effect of taking good photos.

Further, since the determination unit is operated during the exposure period by the control unit, it can be determined whether or not blur can be correctly corrected during a period in which photographing (exposure) is actually being performed. Therefore, it is possible to appropriately take a measure against the blur by shortening the exposure time or the like, as compared with a method of determining whether or not the blur correction is possible before the exposure.

[Brief description of the drawings]

FIG. 1 is a perspective view of a camera to which the present invention is applied.
FIG. 2 is a block circuit diagram of the camera shown in FIG. 1, FIGS. 3 to 6 and FIG. 10 are flowcharts showing the operation of the camera according to the present invention, and FIG. FIG. 8 is a view showing an optical system of the camera, FIG. 8 is a flowchart showing a main part of a method of image blur correction according to the present invention, and FIGS. 9A to 9C are image blur speeds and exposures on a film surface. FIG. 11A to FIG. 13 are flow charts showing the operation of the camera when it is not possible to follow the shake correction according to the present invention, and FIG. 14A and FIG.
The figure is a diagram for explaining the effect when the blur correction is impossible. 11 is a camera body, 12 is a photographing lens, Sx and Sy are angular velocity sensors, LM is a photometry circuit, MD is a distance measurement circuit, AE is an exposure control circuit, Cxy is a blur correction lens control circuit, and FL is a flash circuit. In the drawings, the same reference numerals indicate the same or corresponding parts.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hisayuki Masumoto 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Inside Osaka International Building Minolta Camera Co., Ltd. (72) Inventor Togo Teramoto Azuchi, Chuo-ku, Osaka-shi, Osaka 2-3-3, Osaka-cho, Osaka International Building Minolta Camera Co., Ltd. (56) References JP-A-64-78581 (JP, A) JP-A-2-116835 (JP, A) JP-A-3-95533 (JP) , A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03B 5/00

Claims (4)

(57) [Claims] An image stabilizing camera for preventing a subject image from blurring on an imaging plane of a photographing optical system, wherein a blur detecting means for detecting a blur amount of the subject image on the imaging plane of the photographing optical system; A shake correction unit that corrects a shake of the subject image by driving an optical element that forms at least a part of a photographing optical system based on an output of the shake detection unit; and whether the shake correction unit can correct the shake correctly. A camera with a shake correction function, comprising: a determination unit for determining whether or not the determination is made; and a control unit for operating the determination unit during an exposure period. 2. The camera with a shake correcting function according to claim 1, further comprising an exposure calculating means for calculating an exposure amount of the camera, wherein the determining means performs a determining operation based on the exposure time calculated by the exposure calculating means. The camera with a shake correction function according to claim 1. 3. The camera with a shake correcting function according to claim 2, wherein when the determining means determines that the shake correcting means cannot correct the blur correctly, the camera controls the exposure time calculated by the exposure calculating means to be shortened. 3. The camera with a shake correction function according to claim 2, further comprising control means. 4. The camera with a shake correcting function according to claim 1, wherein the auxiliary light means for illuminating the subject and the auxiliary light means emit light when the determination means determines that the shake correction means cannot correct the blur correctly. Third control means for controlling
The camera with a shake correction function according to claim 1, further comprising: