JPH11109430A - Camera with shake correcting function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the appropriate execution of shake correction corresponding to shake detection accuracy, and the prohibition of the use of a shake detected result or the like in case of the poor accuracy. SOLUTION: A parameter setting part 514c setting first parameters Tv, Tα and (k) at a data selecting part 512 and an estimated shake quantity arithmetic part 513 when the evaluation of the shake detection accuracy is high and setting second parameters Tv, Tαand (k) at them when it is low is provided, and the values of the first parameters Tv and Tα are set to be shorter than those of the second parameters Tv and Tα, and the value of the first parameter (k) is set to be larger than that of the second parameter (k).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera for photographing while correcting camera shake of a camera body with respect to a subject.

[0002]

2. Description of the Related Art In recent years, the use of an area sensor in which a plurality of photoelectric conversion elements such as a plurality of CCDs (charge-coupled devices) are two-dimensionally arranged has detected a shake of a subject image caused by camera shake (image processing method). A camera having a function of correcting the obtained shake amount so as to cancel it has been proposed (Japanese Patent Laid-Open No. 8-51).
566). That is, a reference image is extracted from a subject image captured by an area sensor, a shake amount is detected by comparing the reference image with a reference image, and a predicted shake amount is calculated using a plurality of obtained shake amounts. The camera shake is corrected by controlling the driving of the correction lens in accordance with the predicted shake amount.

[0003]

When the amount of shake is detected by an image processing method using a CCD or the like, if the brightness of the subject changes greatly due to the shooting environment or the like, the amount of light received by each photoelectric conversion element of the area sensor increases. As a result, there is a difference (variation) in the captured subject image, and if a shake is detected using an image captured under the influence of such a luminance difference or the like, the shake amount can be obtained while including the variation. Therefore, there is a problem that proper shake correction cannot be maintained.

The present invention has been made in view of the above circumstances, and has a shake correction function that enables appropriate shake correction according to shake detection accuracy and prohibits the use of a shake detection result when the accuracy is poor. It is an object of the present invention to provide a camera with a camera.

[0005]

According to the present invention, there is provided a vibration detecting device for periodically detecting a camera shake of a camera body with respect to a subject, and detecting a shake amount from a detection result of the shake detecting device. Shake amount detection means, evaluation means for evaluating shake detection accuracy of the shake detection means using a plurality of shake amounts obtained from the shake amount detection means, and parameter setting means for setting a parameter according to the evaluation result; And a predicted shake amount calculating means for calculating a predicted shake amount using the set parameters.

In this configuration, the predicted shake amount is calculated according to the evaluation result of the shake detection accuracy.
Shake correction suitable for shake detection accuracy is performed. For example, when the shake detection accuracy is smaller than a predetermined value, that is, when the evaluation of the shake detection accuracy is high, the predicted shake amount is accurately calculated by using a newer shake amount, and this is positively used. Then, appropriate shake correction matching the shake detection accuracy is performed. On the other hand, when the evaluation of the shake detection accuracy is low, the evaluation of the shake detection accuracy is high so that the magnitude of the variation in the shake detection result is absorbed rather than calculating the accurate predicted shake amount. The plurality of shake amounts may be selected using a time interval longer than the interval used for the calculation, and these may be used for calculating the predicted shake amount. Alternatively, the degree of utilization of the predicted shake amount may be reduced, or the use of the predicted shake amount may be prohibited and the shake correction may be performed based on the shake amount. As a result, shake correction that matches shake evaluation accuracy with a low evaluation is performed.

[0007] The parameter may be a shake detection time interval for determining a selection condition of a plurality of shake amounts used in the prediction calculation. In this configuration, using the shake detection time interval determined according to the evaluation result of the shake detection accuracy,
Since a plurality of shake amounts for the predicted shake amount calculation are selected, the predicted shake amount obtained from the plurality of shake amounts is suitable for the shake detection accuracy. Matched shake correction is performed.

The predictive shake amount calculating means calculates a shake speed and a shake acceleration using a plurality of shake amounts, and performs a shake prediction using an arithmetic expression having the shake speed and the shake acceleration. The parameter may be a coefficient applied to the shake acceleration term. In this configuration, since the coefficient used in accordance with the evaluation result of the shake detection accuracy is multiplied by the shake acceleration term in the calculation formula of the predicted shake amount, the value of the term (the degree of use of the predicted shake amount) is This increases or decreases according to the shake detection accuracy, and shake correction matching the shake detection accuracy is performed.

The shake detection time interval, which is the parameter, has a first time interval and a second time interval longer than the first time interval, and the parameter setting means determines the shake detection accuracy. When the evaluation is high, the first time interval is set as the parameter, and when the evaluation of the shake detection accuracy is low, the second time interval is set as the parameter. According to this configuration, when the evaluation of the shake detection accuracy is high, the predicted shake amount is calculated from the newer shake amount, and when the evaluation of the shake detection accuracy is low, the variation in the shake detection result is reduced. The predicted shake amount is calculated from the shake amount selected using the time interval that absorbs.

Further, the coefficient which is the parameter is a first coefficient.
And a second coefficient smaller than the first coefficient,
The parameter setting means sets the first coefficient as the parameter when the evaluation of the shake detection accuracy is high, and sets the second coefficient as the parameter when the evaluation of the shake detection accuracy is low. May be. According to this configuration, when the evaluation of the shake detection accuracy is high, the usage of the predicted shake amount increases, and when the evaluation of the shake detection accuracy is low, the usage of the predicted shake amount decreases.

[0011]

FIG. 1 is a block diagram of an embodiment of the present invention. The camera 1 includes a photographing unit 2, a correction lens unit 3, a shake detection unit 4, a shake correction amount setting unit 5, a drive unit 6, a position detection unit 7, an exposure control unit 8, a release monitoring unit 9, a distance measurement module 10, and a focus. It comprises a unit 11 and a shake display unit 12.

The photographing unit 2 includes a photographing lens 2 having an optical axis L.
1. An unillustrated mechanism for feeding the loaded film 22 to an image forming position on the optical axis L, and a shutter 23 disposed in front of the film 22 for photographing a subject image.

The correction lens unit 3 includes a horizontal shake correction lens 31 and a vertical shake correction lens 32 disposed in front of the photographing lens 21, and corrects a subject image shake by a prism method. The horizontal shake correction lens 31 and the vertical shake correction lens 32 each have an optical axis parallel to the optical axis L,
It is supported movably in the horizontal and vertical directions orthogonal to each other on a plane orthogonal to the optical axis L.

FIG. 2 is a perspective view of the vertical shake correction lens 32 and the like housed in the lens barrel. In the present embodiment, the vertical shake correction lens 32 is housed in the lens barrel 24 and is attached to a frame 321 supported rotatably at a fulcrum O. A gear portion 322 is formed on the outer peripheral portion of the frame 321 on the side opposite to the fulcrum O. This gear portion 322
When the motor 632 having the gear 631 meshing with the lens is driven, the vertical shake correction lens 32 moves substantially in the vertical direction.
As understood from FIG. 2, the vertical shake correction lens 32 is
Within the movable range R corresponding to the inner diameter of the lens barrel 24, it can be moved substantially vertically. The same applies to the lateral shake correction lens 31.

The shake detector 4 includes a detection lens 41, a shake sensor 42, a shake sensor controller 43, and a signal processor 44.
And obtains image data for detecting a subject image shake caused by a relative shake of the camera 1 main body with respect to the subject. The detection lens 41 is
It has an optical axis parallel to the optical axis L of the taking lens 21, and forms an object image on the shake sensor 42 behind. The shake sensor 42 is an area sensor in which a plurality of photoelectric conversion elements such as CCDs are two-dimensionally arranged.
1 receives the object image formed in step 1 and obtains an electric signal corresponding to the amount of received light. The image signal of the subject image is obtained as a planar set of pixel signals, which are electric signals obtained by being received by the respective photoelectric conversion elements. The shake sensor control unit 43 causes the shake sensor 42 to periodically perform a light receiving operation for a predetermined charge accumulation time (integration time), and sends an image signal obtained in each light receiving operation to the signal processing unit 44. It is. The signal processing section 44 performs predetermined signal processing (processing such as signal amplification and offset adjustment) on each pixel signal from the shake sensor 42 and A / D converts the pixel signal into pixel data.

FIG. 3 is a diagram showing an example of a shake detection area covered by the shake detection section 4. As shown in FIG. In the present embodiment, the shake detection unit 4 is configured to cover a shake detection area A1 located at the center and a shake detection area A2 located at the left side of the shooting screen. That is, the shake sensor 4
Reference numeral 2 denotes a light receiving surface on which a light receiving element is formed to cover the subject image corresponding to the shake detection area A1 among the subject images formed by the detection lens 41, and corresponds to the shake detection area A2. And another light receiving surface on which a light receiving element only for covering the subject image is formed.

Incidentally, the shake detecting section 4 may use a shake sensor 42 which covers the entire photographing screen. in this case,
At the stage of image processing, signals of an area corresponding to the detection areas A1 and A2 may be extracted.

The shake correction amount setting section 5 shown in FIG. 1 includes a shake amount detection section 51, a coefficient conversion section 52, and a target position setting section 5.
3. Correction gain setting unit 54, temperature sensor 55, memory 5
6. The position data input unit 57 and the timer 58 are used to set data for generating a drive signal for shake correction. The temperature sensor 55 is connected to the camera 1
This is to detect the environmental temperature. Also, the memory 56
Is composed of a RAM for temporarily storing image data and data such as the amount of shake used by the shake amount detection unit 51, and a ROM for storing conversion coefficients and the like used by the coefficient conversion unit 52.

FIG. 4 is a block diagram for explaining the configuration of the shake amount detecting section 51. The shake amount detection unit 51 includes a shake amount calculation unit 511, a data selection unit 512, a predicted shake amount calculation unit 513, and an evaluation setting unit 514, and calculates a shake amount using image data from the signal processing unit 44. The expected shake amount is further obtained by using the shake amount.

The shake amount calculating section 511 includes an image data dumping section 511a, a detection area selecting section 511b, and an image comparing / calculating section 511c. The image data dump unit 511a dumps the image data from the signal processing unit 44 to the memory 56 (RAM). Memory 56
Stores image data of each of the shake detection areas A1 and A2.

The detection area selector 511b selects one of the shake detection areas A1 and A2 according to a predetermined selection criterion. As for the selection of the shake detection area, for example, the contrast values of the images in both areas may be compared, and the area having the higher contrast value may be selected.

The detection area selection section 511b determines whether or not the contrast value of the image in the selected shake detection area is lower than a predetermined value (threshold).
Contrast value is set to "1" to Rokonfuragu F _L to indicate a low contrast (low contrast) is lower than a predetermined value. The detection area selection unit 51
1b, once entering the low contrast state, sets the permission flag _FP to "0" in order to prohibit the execution of the calculation processing of the shake detection accuracy described later. This is in consideration of the fact that once entering the low contrast state, there is little chance of leaving the low contrast state in a short time.

The image comparison / calculation section 511c calculates the amount of shake using the image data in the shake detection area selected by the detection area selection section 511b and the reference image.
At the start of the shake detection, the reference image has a predetermined reference position at which each lens of the correction lens unit 3 moves, for example, a center position where each lens can move in the opposite direction by the same distance (Ra =
Rb), the shake detection unit 4
This is an image that is included in the image captured from and serves as a reference for detecting the amount of shake. In this way, by using the center position as a reference, it is possible to avoid the problem that the shake correction lens, which tends to occur when one movable range is shorter than the other, easily hits the end. That is, the image comparison / calculation unit 511c extracts an image corresponding to the reference image from the latest image data stored in the memory 56 as a reference image, and changes the reference image position with respect to the position of the reference image initially set. Is performed to calculate the amount of shake in pixel units from. The shake amount is obtained for each of the horizontal and vertical directions, and is temporarily stored in the memory 56.

Further, the image comparison operation unit 511c, when the number of calculation steps to obtain the shake amount is predicted start count Np or more later, when Rokonfuragu F _L becomes "1", the latest stored in the memory 56 Are used as the horizontal and vertical shake amounts, respectively. This is because, in the case of low contrast, since the reliability of the detected shake amount is low, the latest predicted shake amount is used instead.
This is a process for avoiding a defect such as an error.

FIG. 5 is an explanatory diagram of shake amount data selection and extraction by the data selection unit 512. Data selection unit 512
Is calculated using a predetermined reference time interval (speed calculation time Tv and acceleration calculation time Tα) set by the evaluation setting unit 514 as a parameter for obtaining the predicted shake amount.
The four shake amounts including the latest shake amount are selectively extracted from the memory 56. That is, the shake amount Ea at the latest time point t1 (hereinafter referred to as ta) is selected and extracted, and the time point ta is extracted.
At a time t longer and shorter than Tv (a time interval required for obtaining a shake velocity having required reliability).
3 (hereinafter referred to as tb), and the shake amount Eb at this time point tb is selectively extracted. Further, a time point t5 which is longer and shorter than Tα (a time interval required for obtaining a shake acceleration having required reliability) with respect to the time point ta.
(Hereinafter referred to as tc), and the shake amount Ec at this time Tc is selectively extracted. Further, a time point t7 (hereinafter referred to as td) which is longer and shorter than the above-described Tv with respect to the time point tc is searched, and the shake amount Ed at this time point td is selectively extracted. These four shake amounts Ea, E
b, Ec, Ed and time points ta, tb, tc, td are selectively extracted in each of the horizontal and vertical directions, and stored in the memory 56 correspondingly.

However, the times are older in the order of time points t1, t2,. Each time point represents an intermediate time point of the integration time. Further, upward arrows at each time point indicate detected shake amounts, and these shake amounts are stored in the memory 56.

In the present embodiment, the predetermined reference time interval used by the data selection unit 512 is determined by the evaluation setting unit 514.
Either the shorter one (for example, Tv = 5 ms) or the longer one (for example, Tv = 10 ms) is set.

The data selection unit 512 is not limited to the above selection method, and may be a unit that selects the amount of shake at the time when the separation time is closest to the predetermined reference time interval, or may be shorter than the predetermined reference time interval. Further, the shake amount at the time when the separation time becomes the longest may be selected.

The predicted shake amount calculator 513 shown in FIG.
Is a data selection unit 512 for each of the horizontal and vertical directions.
Is used to calculate the predicted shake amount using the four shake amounts selected and extracted in (1). That is, the latest shake amount Ea and the past shake amount Ea
The shake speed V1 is obtained from the two shake amounts Eb by (Equation 1), and the shake speed V2 is obtained from (Rev. 2) from the remaining two old shake amounts Ec and Ed. Then, the shake acceleration α is obtained from the shake speeds V1 and V2 by (Equation 3).

[0030]

(Equation 1)

[0031]

(Equation 2)

[0032]

(Equation 3)

Next, based on the assumption that the shake due to the hand shake changes substantially in accordance with the uniform acceleration movement, the latest shake amount Ea, shake speed V1 and shake acceleration α, and the constant k set by the evaluation setting unit 514, from the predicted shake amount E _P is calculated by the equation (4). This predicted shake amount is temporarily stored in the memory 56.

[0034]

(Equation 4)

However, a constant k (0 <k <1) is a correction coefficient for approaching an actual camera shake, and is a factor applied to the shake acceleration α. The time T _P is a time obtained from the current time (time tr) from the timer 58 by calculation of tr−ta + Td. Further, the time Td is a delay time required from when the shake amount detection unit 51 sends out the predicted shake amount to when the driving by the correction lens unit 3 is completed. Incidentally, the delay time Td may not be taken into account in the time T _P. Further, the time T _P is given by T _P = (１ ／) × T1 +
It may be determined from the relationship of T2 + T3 + T4 + Td. Here, the time T1 is the integration time of the shake sensor 42, and the time T2 is the image information of the shake sensor 42 is stored in the memory 56.
The transfer time and time T3 required to be dumped to the memory are calculated time for calculating the shake amount, and time T4 is the predicted calculation time for calculating the calculated shake amount.

Further, the predicted fluctuation amount calculating section 513, if the number of calculation steps of the shake amount calculation unit 511 is less than the predicted start count Np, when Rokonfuragu F _L becomes "0",
The latest horizontal and vertical shake amounts stored in the memory 56 are used as predicted horizontal and vertical shake amounts, respectively.
Thus, when the shake correction based on the predicted shake amount starts, the drive of the smooth shake correction is performed.

The evaluation setting section 514 includes the detection accuracy calculation section 51
4a, detection accuracy evaluation section 514b and parameter setting section 5
14c, the shake detection accuracy is calculated and evaluated from the shake detection result, and according to the evaluation result, the above-described parameters of the speed calculation time Tv, the acceleration calculation time Tα, and the constant k (hereinafter simply referred to as parameters Tv, Tα) , K).

The detection accuracy calculation section 514a calculates the shake detection accuracy of the shake detection section 4 using the shake acceleration.

FIGS. 6A and 6B are diagrams showing variations in the results of the shake detection. FIG. 6A shows a state of a variation including a displacement due to a failure in mounting the shake sensor and the like, and FIG. 6B shows a factor of the variation. There is no variation. If the shake detection result is biased to either side (upward in the figure) with respect to the true value of the shake as shown in FIG. 6A, the bias is not due to the shake detection accuracy, but is due to the attachment of the shake sensor. This is due to a defect or the like. If there is no such deviation, the shake detection result will be in a state of variation that sandwiches the true value of the shake as shown in FIG. The shake detection accuracy indicating a detection result in such a non-uniform variation state is represented by a calculation result by the following method executed by the detection accuracy calculation unit 514a.

FIG. 7 is an explanatory diagram of the shake detection accuracy measurement.
(A) shows a shake detection result when the variation is large,
(B) shows a shake detection result when the variation is small. Vibration amounts Ea to Ed shown in FIGS.
Since the time between them is selected and extracted at the above-mentioned reference time interval, it is about 30 ms at best.

For example, as shown in FIG.
If peaks and valleys exist at a time of about 0 ms, the waveform has a frequency higher than 10 Hz which is the upper limit value of the hand shake of the person, and therefore includes a shake detection error not caused by the hand shake of the person. it is conceivable that. In the present embodiment, since the shake detection unit 4 employs the image processing method,
In the case of low luminance, the accuracy of shake detection is reduced, and FIG.
In some cases, the result of the shake detection as shown in FIG. On the other hand, in the case of a high luminance, the detection accuracy is high, and as shown in FIG.

Therefore, the shake detection accuracy of Ea to Ed may be represented by considering the variation as shown in FIG. 6B, and may be represented by the change amount of the shake speed. In the present embodiment, the vibration acceleration is represented by a change amount. In this case, since the shake detection accuracy of Ea to Ed requires at least three shake amounts to calculate the shake acceleration α, for example, the shake acceleration by Ea to Ec and Eb
When the shake acceleration due to .about.Ed is used, it is expressed by a shake acceleration change C of (Equation 5).

[0043]

(Equation 5)

However, since the integration period of each image signal used to obtain Ea to Ed can be regarded as substantially constant, t
a-tb, tb-tc, tc-td have the same integration period T
It's 1 '. In addition, since the purpose is to represent the state of variation, it is not necessary to accurately determine the shake acceleration change C. It is sufficient if a value corresponding to the change is obtained. , T ′ = 1 or is ignored and calculated. Thereby, the calculation processing time can be reduced.

The obtained value of the vibration acceleration change C is integrated. This integrated value (sum) is obtained for the square value of each shake acceleration change C since each shake acceleration change C has a sign. The final shake detection accuracy of the shake detection unit 4 is represented by the average value of the sum in the horizontal and vertical directions, that is, (total sum in the horizontal direction + sum total in the vertical direction) / 2. The number of times of shake accuracy detection is preferably about 20 in consideration of a quick calculation process for obtaining an evaluation quickly (a slow shake shortens an appropriate shake correction time) and an appropriate statistical process.

Although the above-mentioned sum is obtained by the square value of each shake acceleration change C, it may be obtained by the absolute value of each shake acceleration change C. In addition, the final shake detection accuracy of the shake detection unit 4 is represented by the average value of the sum in the horizontal and vertical directions. However, the present invention is not limited to this. Or you may make it represent using the larger value.

In addition, there is a method in which judgment is made individually in the vertical and horizontal directions. However, in this case, the selection time of data used for prediction is doubled and the processing time becomes longer. Is more preferred.

The detection accuracy evaluation section 514b shown in FIG.
Indicates whether the shake detection accuracy of the shake detection unit 4 is high using a predetermined evaluation criterion value obtained by assuming a camera shake as a sin waveform or the like and obtaining a change in acceleration as a detection result with a predetermined variation. The evaluation (judgment) is performed.
That is, if the shake detection accuracy value from the detection accuracy calculation unit 514a is smaller than the above-described evaluation reference value, the shake detection accuracy is evaluated as high (the variation is small), and otherwise, the shake detection accuracy is low (the variation is small). Large). At this time, evaluation flag F _B is the larger the variation, i.e. evaluation of the result if the lower "1", the smaller the variation, i.e. the evaluation result is set to "0" is higher.

The parameter setting unit 514c determines the parameters Tv, Tv according to the evaluation result of the detection accuracy evaluation unit 514b.
α and k are set to the data selection unit 512 and the predicted shake amount calculation unit 51
3 is set. Here, a parameter set when the evaluation result is high is called a first parameter, and a parameter set when the evaluation result is low is called a second parameter. The values of Tv and Tα of the first parameter are respectively equal to Tv of the second parameter.
It is set to be smaller than the values of v and Tα, and the value of k of the first parameter is equal to or larger than the value of k of the second parameter. That is, the parameter setting unit 514
c, if evaluation flag F _B is "0" permission flag F _P at "1", it sets the first parameter, evaluation flag F _B is any "1" or permission flag F _P is "0" If
The second parameter is set.

FIGS. 8A and 8B show the results of detection of a shake having a variation of ± σ with respect to the true value of the shake. FIG. 8A shows the influence of the error of the shake amount selectively extracted using the first parameter Tv. FIG. 7B is a diagram illustrating the influence of an error in the shake amount selectively extracted using the second parameter Tv. However, R1, R2, and R3 are the shake amounts E1, E2, respectively.
It shows the true value of the shake (true shake amount) for E3.

In FIGS. 8A and 8B, the shake speed V _ba including the maximum error is obtained by ( _Equation 6).

[0052]

(Equation 6)

The 2 × σ / Tv in the above equation is the true shake speed (R
1-R2) / Tv. Here, the first
The parameter Tv is set to Tv1, and the second parameter Tv
Assuming that v is Tv2, the error in the case of FIG.
σ / Tv1, the error in the case of FIG. 8A is 2 × σ / Tv
It becomes 2. At this time, since the relationship of Tv1 <Tv2 holds, the relationship of the error is 2 × σ / Tv1> 2 × σ /
Tv2. Thus, when the variation σ is large,
It is understood that the error can be reduced by using the second parameter Tv.

Therefore, in this embodiment, when the variation σ is large, that is, when the evaluation result is low, the second parameters Tv and Tα are used. Also, in this case, since the reliability of the shake acceleration term of (Equation 4) is low, the second parameter k having a smaller value than the first parameter k is used to reduce the influence of the error.

On the other hand, when the evaluation result is high, the first parameter Tv, Tα is used to use the amount of shake obtained as close as possible to the current time, thereby reducing the shake correction accuracy. To keep it high.
In this case, since the reliability of the shake acceleration term is high, the first parameter k having a larger value than the second parameter k is used to positively reflect the shake acceleration term in the shake prediction. .

FIG. 9 is a graph of a simulation of the shake correction accuracy based on the first and second parameters. In this simulation, the vibration of the camera shake is determined based on a sin waveform. In FIG. 9, the first curve is sin
This represents a shake correction accuracy (remaining correction) which is a difference between a shake amount of the waveform and a predicted shake amount obtained by the first parameter with respect to the sin waveform. Similarly, the second curve is si
The shake correction accuracy (remaining correction), which is the difference between the shake amount of the n waveforms and the predicted shake amount obtained by the second parameter for the sin waveform, is shown.

As shown in FIG. 9, the shake correction accuracy is:
If the shake detection accuracy value is smaller than the evaluation reference value, it is understood that the predicted shake amount obtained using the first parameter has better shake correction accuracy. On the other hand, if the shake detection accuracy value is larger than the evaluation reference value, the predicted shake amount obtained using the second parameter has better shake correction accuracy. In the present embodiment, the evaluation reference value used by the detection accuracy evaluation unit 514b is obtained in advance by such a simulation.

FIG. 10A is a diagram showing the evaluation reference values of FIG. 9 by specific numerical values. Shake correction accuracy (remaining correction)
If the shake detection accuracy value is smaller than the evaluation reference value of 0.007563 [deg], it is higher when the first parameter is used, and when it is larger, the use of the second parameter is higher.

In this embodiment, the shake detection accuracy is:
The calculation is performed from the change in the shake acceleration. However, the calculation is not limited thereto.
The specific simulation result of FIG. 9 is shown in FIG.
It becomes as shown in.

Returning to FIG. 1, the coefficient converter 52 calculates the horizontal and vertical predicted shake amounts by using the conversion coefficients stored in the memory 56 to set the horizontal and vertical target angles with respect to the correction lens unit 3. It is converted into a position (driving amount). Further, the coefficient conversion unit 52 calculates a correction coefficient according to the environmental temperature detected by the temperature sensor 55, and corrects the horizontal and vertical target angle positions using the correction coefficient. This correction factor is
This is for correcting a change in the focal length of the detection lens 41 and a change in the refractive index (power) of light caused by the correction lens unit 3 due to a change in environmental temperature.

The target position setting section 53 converts the target angle position in the horizontal and vertical directions after temperature correction into target position information (drive end position). These horizontal and vertical target position information are set in the drive unit 6 as setting data SD _PH and SD _PV , respectively.

[0062] Also, the target position setting unit 53, when the processing number of the shake amount calculation unit 511 is less than the predicted start count Np, when Rokonfuragu F _L becomes "1", the previous setting data SD _PH, The drive unit 6 is set again by using the SD _PV . Thus, each lens of the correction lens unit 3 is stopped at the current position.

The correction gain setting section 54 includes a temperature sensor 55
The gain correction amounts in the horizontal and vertical directions are obtained according to the environmental temperature detected in step (1), and the respective gain correction amounts are output to the drive unit 6 as setting data SD _GH and SD _GV . The horizontal and vertical gain correction amounts correct the horizontal and vertical basic gains, respectively. Details of the setting data SD _GH and SD _GV and the basic gain will be described later.

The position data input section 57 A / D converts each output signal of the position detection section 7 and monitors each position of the horizontal shake correction lens 31 and the vertical shake correction lens 32 from the obtained output data. Things. By monitoring this position data, it is possible to detect an abnormal state of the drive mechanism for the correction lens unit 3 and the like.

The drive section 6 comprises a drive control circuit 61, a horizontal actuator 62 and a vertical actuator 63. The drive control circuit 61 includes setting data SD _PH and S _PH from the target position setting unit 53 and the correction gain setting unit 54.
It generates horizontal and vertical drive signals in accordance with D _PV , SD _GH , and SD _GV . The horizontal actuator 62 and the vertical actuator 63 are composed of a coreless motor or the like (see the motor 632 and the gear 631 in FIG. 2), and perform horizontal vibration correction according to the horizontal and vertical drive signals generated by the drive control circuit 61, respectively. The lens 31 and the vertical shake correction lens 32 are driven.

FIG. 11 is a block diagram showing an example of the drive control circuit 61 constituting a part of the servo circuit. First,
Setting data SD _GH , S set in the drive control circuit 61
D _GV will be described. When the environmental temperature of the camera 1 changes, various characteristics of the drive system for shake correction change. For example, the torque constant of each motor (see the motor 632 in FIG. 2) in the drive unit 6 and the drive system (movable mechanism) in the correction lens unit 3 and the drive unit 6 according to the environmental temperature change.
, And the hardness of the gears (see gear 322 and gear 631 in FIG. 2) of the drive system change.

FIG. 12 is a temperature characteristic diagram of the motor torque which is a factor of this change. As understood from FIG. 12, when the environmental temperature deviates from the reference temperature (for example, 25 ° C.), the motor torque shows a value different from the value at the reference temperature. As a result, the drive characteristics related to the shake correction change. As described above, the driving characteristics based on the basic gain in the horizontal and vertical directions (the driving gain at the reference temperature) are as follows.
When the environmental temperature obtained by the temperature sensor 55 deviates from the reference temperature, the temperature fluctuates.

Therefore, the correction gain setting section 54 generates a gain correction amount for correcting a variation in drive characteristics due to each of the basic gains in the horizontal and vertical directions according to the environmental temperature obtained by the temperature sensor 55. In the present embodiment, a function (environment temperature is used as an argument) for obtaining a gain correction amount for individually correcting each variation such as motor torque, backlash, and gear hardness that occurs when the environment temperature deviates from the reference temperature. )But,
It is determined in advance for each of the horizontal and vertical directions. Then, for each of the horizontal and vertical directions, the environmental temperature detected by the temperature sensor 55 is input to each correction function, and the total value of the obtained values is obtained as a gain correction amount. These gain correction amounts in the horizontal and vertical directions are respectively set in the setting data SD.
_GH and SD _GV are set in the drive control circuit 61.

Next, the drive control circuit 61 will be described. In FIG. 1, the setting data SD _GH , SD
_{The GV} is illustrated as being transmitted on two signal lines, but actually, two data lines (SCK, SD) not shown
And serially transmitted and set by three control lines (CS, DA / GAIN, X / Y). Similarly, the setting data D _PH and SD _PV are sent to the drive control circuit 61 alternately.

For this purpose, the drive control circuit 61 includes a buffer, a sample and hold circuit, and the like. That is, FIG.
1, the buffers 601 and 602 store setting data SD alternately set from the target position setting unit 53, respectively.
It is a memory for storing _PH and SD _PV .

The DAC 603 is a D / A converter, and converts the setting data SD _PH set in the buffer 601 into a target position voltage V _PH . Further, the DAC 603 converts the setting data SD _PV set in the buffer 602 into a target position voltage V _PV .

S / Hs 604 and 605 are sample and hold circuits. The S / H 604 samples the target position voltage V _PH converted by the DAC 603, and holds the value until the next sampling. Similarly, S / H605
Samples the target position voltage V _PV converted by the DAC 603 and holds the value until the next sampling.

The adder circuit 606 calculates the difference voltage between the target position voltage V _PH and the output voltage V _H from the lateral position detector 71. The addition circuit 607 calculates a difference voltage between the target position voltage V _PV and the output voltage V _V from the vertical position detection unit 72. That is, in the addition circuit 606 and 607, the output voltage V _H in a negative voltage at the lateral position detection unit 71 and the vertical position detector 72, respectively, since to obtain a V _V, the differential voltage is obtained by adding.

V / V 608 amplifies the input voltage to a voltage as a lateral proportional gain at a preset ratio with respect to the reference temperature. V / V 609 converts the input voltage to the reference temperature. To a voltage set as a proportional gain in the vertical direction at a preset ratio. Here, the proportional gain in the lateral direction refers to the lateral shake correction lens 31.
Is a gain proportional to the difference between the target position of the horizontal shake correction lens 31 and the position of the lateral shake correction lens 31 detected by the horizontal position detection unit 71. The vertical proportional gain is a gain proportional to the difference between the target position of the vertical shake correction lens 32 and the position of the vertical shake correction lens 32 detected by the vertical position detection unit 72.

The differentiating circuit 610 performs differentiation by a preset time constant with respect to the reference temperature to the difference voltage obtained by the adding circuit 606 to obtain a voltage as a differential gain in the horizontal direction. The obtained voltage corresponds to a speed difference in the lateral direction (difference between the target drive speed and the current drive speed). Similarly, the differentiating circuit 611 obtains a voltage as a differential gain in the vertical direction by performing differentiation by a preset time constant with respect to the reference temperature on the difference voltage obtained by the adding circuit 607. The obtained voltage corresponds to a vertical speed difference (difference between the target driving speed and the current driving speed).

As described above, the proportional and differential gains as the basic gain with respect to the reference temperature are set by the V / Vs 608 and 609 and the differentiation circuits 610 and 611 in each of the horizontal and vertical directions.

The buffer 612 includes the correction gain setting section 54
It is a memory for storing the setting data _SDGH from. The setting data _SDGH is a gain correction amount (proportional and differential gain correction amount) for correcting the horizontal basic gain (proportional and differential gain). The buffer 613 is a memory that stores the setting data SD _GV from the correction gain setting unit 54. The setting data SD _GV is a gain correction amount (proportional and differential gain correction amount) for correcting the vertical basic gain (proportional and differential gain).

The HP gain correction circuit 614 has a V / V60
8 with respect to the horizontal proportional gain obtained in
An analog voltage corresponding to the horizontal proportional gain correction amount from 12 is added to output a horizontal proportional gain after temperature correction. The VP gain correction circuit 6
Numeral 15 adds an analog voltage corresponding to the vertical proportional gain correction amount from the buffer 613 to the vertical proportional gain obtained by the V / V 609, and outputs a vertical proportional gain after temperature correction. Is what you do.

The HD gain correction circuit 616 is
An analog voltage corresponding to the horizontal differential gain correction amount from the buffer 612 is added to the horizontal differential gain obtained in step 10 to output the horizontal differential gain after temperature correction. Further, the VD gain correction circuit 617 adds an analog voltage corresponding to the vertical differential gain correction amount from the buffer 613 to the vertical differential gain obtained by the differentiating circuit 611, and outputs the vertical differential gain after temperature correction. It outputs the differential gain in the direction.

As described above, the HP gain correction circuit 614,
VP gain correction circuit 615, HD gain correction circuit 616
And the VD gain correction circuit 617 performs temperature correction on the proportional and differential gains as the basic gain.

The LPF 618 includes an HP gain correction circuit 61
4 and a low-pass filter for removing high-frequency noise included in each output voltage of the HD gain correction circuit 616. L
The PF 619 is a low-pass filter that removes high-frequency noise included in each output voltage of the VP gain correction circuit 615 and the VD gain correction circuit 617.

The driver 620 includes LPFs 618 and 61
9 is a motor driving IC that supplies drive power corresponding to the output voltage of No. 9 to the horizontal actuator 62 and the vertical actuator 63, respectively.

Returning to FIG. 1, the position detecting section 7 includes a horizontal position detecting section 71 and a vertical position detecting section 72.
The horizontal position detector 71 and the vertical position detector 72 detect the current positions of the horizontal shake correction lens 31 and the vertical shake correction lens 32, respectively.

FIG. 13 is a block diagram of the horizontal position detecting section 71. The horizontal position detection unit 71 includes a light emitting diode (LED) 7.
11, slit 712 and position detection element (PSD) 71
Three. The LED 711 is provided for the horizontal shake correction lens 3.
It is attached to the formation position of the gear portion in one frame 311 (see LED 721 in FIG. 2). Slit 71
Reference numeral 2 is for sharpening the directivity of light emitted from the light emitting unit of the LED 711. The PSD 713 is the lens barrel 2
4 is attached to a position facing the LED 711 on the inner wall side. The PSD 713 outputs photoelectric conversion currents I1 and I2 having values corresponding to the light receiving position (center of gravity position) of the light beam emitted from the LED 711. Photoelectric conversion current I1,
By measuring the difference of I2, the position of the lateral shake correction lens 31 is detected. Vertical position detector 72
Is also configured to detect the position of the vertical shake correction lens 32 in the same manner.

FIG. 14 is a block diagram of the horizontal position detector 71. The horizontal position detection unit 71 includes the LED 711 and the PSD
In addition to the components 713, I / V conversion circuits 714 and 715, an addition circuit 716, a current control circuit 717, a subtraction circuit 718, an LPF 719, and the like. The I / V conversion circuits 714 and 715 respectively output the output current I
1, I2 are converted into voltages V1, V2. The addition circuit 716 obtains an addition voltage V3 of the output voltages V1 and V2 of the I / V conversion circuits 714 and 715. The current control circuit 717 increases or decreases the base current of the transistor Tr1 so as to keep the output voltage V3 of the adder circuit 716, that is, the light emission amount of the LED 711 constant. The subtraction circuit 718 calculates a difference voltage V4 between the output voltages V1 and V2 of the I / V conversion circuits 714 and 715. LPF
Reference numeral 719 cuts a high-frequency component included in the output voltage V4 of the subtraction circuit 718.

Next, the detection operation by the horizontal position detector 71 will be described. Current I sent from PSD 713
1 and I2 are converted into voltages V1 and V2 by I / V conversion circuits 714 and 715, respectively.

Next, the voltages V1 and V2 are added to the adder 716.
Is added. The current control circuit 717 supplies a current at which the voltage V3 obtained by the addition is always constant to the base of the transistor Tr1. The LED 711 emits light with a light amount corresponding to the base current.

On the other hand, the voltages V1 and V2 are subtracted from the subtraction circuit 718.
Is subtracted. The voltage V4 obtained by this subtraction is a value indicating the position of the lateral shake correction lens 31. For example, when the light receiving position is located at a position that is distance x to the right from the center of the PSD 713, the length x, the currents I1, I2, and the light receiving area length L of the PSD 713 satisfy the relationship of (Equation 7).

[0089]

(Equation 7)

Similarly, the length x, the voltages V1 and V2, and the light receiving area length L satisfy the relationship of (Equation 8).

[0091]

(Equation 8)

Thus, the value of V2 + V1, that is, the voltage V3
Is controlled to be always constant, the relationship of (Equation 9) is obtained, and the value of V2−V1, that is, the value of the voltage V4 becomes the length x
The position of the lateral shake correction lens 31 can be detected by monitoring the voltage V4.

[0093]

(Equation 9)

The exposure control unit 8 shown in FIG.
1 and an exposure determining unit 82. Photometry section 8
Reference numeral 1 denotes a photoelectric conversion element such as Cds (cadmium sulfide) that receives light from a subject and detects the brightness of the subject (subject brightness). The exposure determining unit 82 determines an appropriate exposure time (tss) according to the subject brightness. The shutter 23 is opened and closed by a shutter opening / closing unit (not shown), and is closed when the elapsed time from the opening time becomes equal to or longer than an appropriate exposure time.

The release monitor 9 determines whether or not the shutter release button has been half-pressed to turn on the switch S1, and whether or not the shutter release button has been fully pressed to turn on the switch S2. The judgment is performed. When the switch S1 is turned on, a photographing preparation process is executed, and when the switch S2 is turned on, a photographing process is executed.

The distance measuring module 10 includes an LED that emits infrared light, and a one-dimensional PSD that receives light from the LED that is reflected back from the subject, and measures the subject distance in accordance with the light receiving position of the PSD. It is a distance. The distance measuring module 10 is not limited to the active type, but may be an external light passive module including a pair of line sensors that receive light from a subject. In the external light passive module, a subject image is received by a pair of line sensors, and distance measurement data corresponding to a distance to the subject is obtained from a phase difference between the two line sensors.

The focus unit 11 is provided with the distance measuring module 10
The amount of defocus (the amount of deviation from in-focus) is obtained in accordance with the distance measurement information from the camera, and the photographing lens 21 is driven to the in-focus position in accordance with the amount of defocus.

The shake display section 12 displays the state of the shake according to the magnitude of the shake amount from the shake amount detection section 51, for example, using an LED segment or the like in the viewfinder. As a result, the current camera shake amount can be recognized. The shake amount itself may be displayed.

In this embodiment, the exposure determining unit 82
The release monitoring unit 9 and the focus unit 11 (focus control unit) are configured in a software form by a microprocessor unit (μC1) that executes a program in which overall processing of the camera 1 other than shake correction is described. On the other hand, the shake sensor control unit 43, the signal processing unit 44, the shake amount detection unit 51, the coefficient conversion unit 52, the target position setting unit 53, the correction gain setting unit 54, and the position data input unit 57 perform the shake correction processing. Is configured in software by another microprocessor unit (μC2) that executes the program described.

Next, the operation of the camera 1 will be described.
FIG. 15 is a control flowchart executed by μC1 and μC2. When the main switch (not shown) is turned on, μC
1 starts μC2 and determines whether or not the switch S1 is turned on (S5). This determination is made by the switch S1
Is repeated until it is turned on (NO in S5).

When the switch S1 is turned on (YE in S5)
S), an S1 command indicating “S1 ON” is transmitted to μC2 (S10).

Thereafter, the luminance of the subject is detected (photometry) and the distance to the subject is measured (distance measurement) (S
15). Thereafter, focal length data is obtained. These photometric data, ranging data and focal length data are expressed in μC
2 (S20).

On the other hand, the μC2 determines whether or not the switch S1 has been turned on in accordance with whether or not the S1 command has been received (# 5). This determination is repeated until the switch S1 is turned on, that is, until the S1 command is received (NO in # 5).

If it is determined that switch S1 has been turned on (YES in # 5), photometric data, distance measuring data and focal length data are received (# 10). Next, a subject image is picked up as shake detection (# 15), and a shake amount is calculated by a shake amount calculation using the picked-up image (# 2).
0). A shake display indicating a shake state is performed on the shake display unit 12 in accordance with the shake amount (# 25).

In the μC1, after the transmission in step S20, it is determined whether or not the switch S2 is turned on (S2).
5). This determination is repeated until the switch S2 is turned on (NO in S25). When switch S2 is turned on (YES in S25), an S2 command indicating "S2 on" is transmitted to μC2 (S30). Next, the photographing lens 21 is driven toward the in-focus position according to the distance measurement data obtained by the distance measurement in step S15 (S35).

On the other hand, in the μC2, after the display in step # 25, the switch S is switched according to the reception of the S2 command.
It is determined whether or not No. 2 is turned on (# 30). If it is determined that the switch S2 has not been turned on (# 30)
NO), and returns to step # 15. Thereby, shake detection, shake amount calculation and shake display are repeatedly executed.

If it is determined that switch S2 has been turned on (YES in # 30), initialization is performed (# 35).
For example, Rokonfuragu F _L, count "i" is "0"
, The evaluation flag F _B, permission flag F _P is initialized to "1". Next, each lens of the correction lens unit 3 is driven to the center position (# 40), and a shutter open signal is transmitted after the end of the focus driving in step S35 so that the μC1 recognizes it (# 45).

In order to transmit the shutter open signal after the end of the focus driving, for example, a predetermined waiting time may be provided at the beginning of the initial setting. In this case, the longest time required for focus driving may be obtained in advance, and the predetermined waiting time may be set so that the processing time in steps # 35 and # 40 is longer than the longest time. This makes it possible to shift the starting points of the driving of the correction lens unit 3 to the center position and the focus driving, thereby dispersing the generation points of the transient current at the time of starting. As a result, an effect of preventing the microcomputer from malfunctioning due to the superimposed transient current is obtained.

In the μC1, after the end of the focus driving in step S35, it is determined whether or not to open the shutter 23 according to whether or not a shutter opening signal has been received (S40).
This determination is repeated until a shutter open signal is received (NO in S40).

When the shutter open signal is received, that is, when the shutter 23 is opened (YES in S40), the shutter 23 is opened and exposure is started (S45). Measured. When the elapsed time reaches the proper exposure time tss or more, a shutter close signal is transmitted to the μC2 (S50). Thereafter, the process returns to step S5.

On the other hand, in μC2, after step # 45,
A subroutine of a "shake correction sequence" to be described later is executed (# 50), and depending on whether or not a shutter close signal has been received,
It is determined whether or not the shutter 23 is closed (# 5).
5). If the shutter close signal is not received, the shutter 2
Without closing 3 (NO in # 55). Step # 50
Return to As a result, until the elapsed time becomes equal to or longer than the appropriate exposure time, the process of the “vibration correction sequence” is repeatedly executed. When the shutter close signal is received (#
If YES at 55, the shutter 23 is closed (# 6)
0). Thereafter, the process returns to step # 5.

FIG. 16 is a flowchart of a subroutine of the "shake correction sequence". When this subroutine is called, a subject image is picked up as shake detection (# 150), and a calculation process for obtaining horizontal and vertical shake amounts from the picked-up image is executed (# 155). At this time, when the contrast value of a captured image is lower than a predetermined value, Rokonfuragu F _L is set to "1".

[0113] Next, a determination is made whether Rokonfuragu F _L is "1"(# 160). When Rokonfuragu F _L is not "1" (NO in # 160), the counter "i" is incremented by "1"(# 16
5) A subroutine of "detection accuracy calculation process" described later is executed (# 170).

Thereafter, an evaluation (judgment) is made as to whether or not the shake detection accuracy of the shake detection section 4 is high (# 175). When the shake detection accuracy is high (YES in # 175), evaluation flag F _B is "0" is set to (# 180), otherwise (NO at # 175), the step # 180 is skipped.

Next, the counter “i” indicates the number of prediction start times N
It is determined whether or not p is greater than or equal to p (# 185). When the counter “i” is equal to or greater than the number Np of predicted starts, (#
185), a “parameter set” subroutine described below is executed (# 190), and a “prediction calculation” described later
Is executed (# 195).

Thereafter, the setting data SD _PH and SD _PV are set in the drive control circuit 61 (# 200). After that, it returns. Thereby, horizontal and vertical drive signals are generated, and each lens of the correction lens unit 3 is driven according to the corresponding drive signal. Note that the setting data SD _GH and SD _GV by the correction gain setting unit 54 are set when the setting data SD _PH and SD _PV by the target position setting unit 53 are set for the first time.

At step # 185, if the counter “i” is not equal to or greater than the predicted start number Np (NO), the latest horizontal and vertical shake amounts stored in the memory 56 are
Used as the predicted shake amount in the horizontal and vertical directions (# 20
5). After each of these predicted shake amounts is converted into a target angle position and subjected to temperature correction, the process proceeds to step # 200.
Thereby, the target angle positions in the horizontal and vertical directions subjected to the temperature correction are set in the drive control circuit 61 as setting data SD _PH and SD _PV , respectively, and each lens of the correction lens unit 3 is stored in the memory 56. In accordance with the latest horizontal and vertical shake amounts, drive is performed so as to correct subject image shake due to camera shake.

[0118] On the other hand, at step # 160, when Rokonfuragu F _L is "1" (YES), permission flag F
_P is set to "0"(# 210). Next, it is determined whether or not the counter “i” is equal to or more than the number Np of predicted starts (# 215). If the counter “i” is equal to or greater than the number Np of predicted starts (YES in # 215), the memory 56
Are used as the horizontal and vertical shake amounts respectively (# 22).
0). Thereafter, the process proceeds to step # 190. This allows
Each lens of the correction lens unit 3 is driven so as to correct the subject image shake due to the camera shake according to the latest predicted shake amounts in the horizontal and vertical directions stored in the memory 56.

If the counter "i" is not equal to or greater than the number Np of predicted starts (NO in # 215), the previous set data S
D _PH and SD _PV are used again (# 225). After this,
Go to step # 200. As a result, the previous setting data SD _PH and SD _PV are set again in the drive control circuit 61, and each lens of the correction lens unit 3 stops at the current position.

FIG. 17 is a flowchart of a subroutine of "detection accuracy calculation processing". When this subroutine is called, it is determined whether or not the counter "i" is less than "4"(# 250). If the counter "i" is less than "4" (YES in # 250), the flow proceeds to step # 185 in FIG. 16, otherwise (# 25
(NO at 0), it is determined whether or not the counter "i" is larger than "20"(# 255).

If the counter "i" is larger than "20" (YES in # 255), the process proceeds to step # 185; otherwise (NO in # 255), whether or not the permission flag _FP is "1" Is determined (# 260). Permission flag F _P is not the "1" (NO in # 260),
Go to step # 185.

[0122] If the permission flag F _P is set to "1"(# 26
0, YES), the lateral vibration acceleration change C is calculated by the calculation of (Equation 5), and the square value of the vibration acceleration change C is calculated (# 270). Then, the by transverse square value C ² is integrated in the lateral direction of the sum of previously obtained, the sum of the current horizontal direction is determined (# 275).

Similarly, the change in the vertical vibration acceleration C is obtained by the calculation of (Equation 5), and the square value of the vibration acceleration change C is calculated (# 280). Then, this by vertical square value C ² is integrated in the longitudinal direction of the sum previously obtained, the sum of the current vertical direction is obtained (# 28
5).

Next, it is determined whether or not the counter "i" is 20 (# 290). Counter “i” is 2
If 0 (YES in # 290), the shake detection accuracy of the shake detection unit 4 is calculated from (total in the horizontal direction + total in the vertical direction) / 2 (# 295). After that, it returns. If the counter “i” is not 20 (NO in # 290), the process proceeds to step # 185.

FIG. 18 is a flowchart of a subroutine "parameter set". When this subroutine is called, evaluation flag F _B is "1", it is determined whether the performed (# 300). Evaluation flag F _B is set to "1"
(YES in # 300), Tv and Tα of the second parameter are set in the data selection unit 512, and k of the second parameter is set in the predicted shake amount calculation unit 513 (# 305). After that, it returns.

[0126] When the evaluation flag F _B is not "1"(#
(NO at 300), it is determined whether or not permission flag _FP is "1"(# 310). When the permission flag _FP is “1” (YES in # 310), the first parameters Tv and Tα are set in the data selection unit 512, and
The first parameter k is set in the predicted shake amount calculation unit 513 (# 315). After that, it returns. If the permission flag _FP is not "1" (NO in # 310), the process proceeds to step # 305.

FIG. 19 is a flowchart of a subroutine of "prediction calculation". When this subroutine is called, a subroutine of “selection and extraction of shake amount” described below is executed (# 350), and a plurality of shake amounts necessary for calculating the predicted shake amount are selectively extracted from the memory 56.

FIG. 20 is a flowchart of a subroutine "selection and extraction of shake amount". Note that each time is shown in FIG.
, And the time point t1 corresponds to the latest detection time point.

When this subroutine is called, the counter "n" is set to "1"(# 400), incremented by "1"(# 405), and the time interval T
_1n (= t1-tn) is calculated (# 410). Next, it is determined whether or not the time interval T _1n is shorter than Tα (# 415). If the time interval T _1n is shorter than Tα (YES in # 415), the process returns to step # 405.

On the other hand, when the time interval T _1n is not shorter than Tα (NO in # 415), the value of the counter "n" is set in the counter "m"(# 420). As a result, the value of the counter “n” is stored, and the shake amount E shown in FIG.
The search for the time tc for specifying c is completed.

Thereafter, the counter "m" is incremented by "1"(# 425), and the time interval T _nm (= tn
−tm) is calculated (# 430). Next, it is determined whether or not the time interval T _nm is shorter than Tv (# 43).
5). If the time interval T _nm is shorter than Tv (YES in # 435), the process returns to step # 425.

On the other hand, if the time interval T _nm is not shorter than Tv (NO in # 435), the counter "h" is set to "1"(# 440). As a result, the value of the counter “m” is stored, and the search for the time td for specifying the shake amount Ed shown in FIG. 5 is completed.

Thereafter, the counter "h" is incremented by "1"(# 445), and the time interval T _1h (= t1
−th) is calculated (# 450). Next, it is determined whether or not the time interval T _1h is shorter than Tv (# 45).
5). If the time interval T _1h is shorter than Tv (YES in # 455), the flow returns to step # 445.

On the other hand, if the time interval T _1h is not shorter than Tv (NO in # 455), the process proceeds to extraction of the next data (# 460).

In step # 460, step # 415
The shake amount at the time point tn specified by the value of the counter “n” when the determination of NO is made is extracted as the shake amount Ec at the time point tc shown in FIG. Further, the shake amount at the time point tm specified by the value of the counter “m” when the determination in step # 435 is NO is extracted as the shake amount Ed at the time point td shown in FIG. Further, the shake amount at the time point th specified by the value of the counter “h” when the determination in step # 455 is NO is the shake amount Eb at the time point tb shown in FIG.
Is extracted as The shake amount Ea at the latest time point t1 (= ta) is always extracted. After that, it returns.

After step # 350 in FIG. 19, the shake speed V1 and the shake acceleration α are calculated for each of the horizontal and vertical directions (# 355). Next, the current time tr is captured by the measurement of the timer 58 (# 360), and (t
After r-ta + td time T _P in operation) has been calculated, for each of the horizontal and vertical directions, the predicted shake amount E _P in the calculation of the equation (4) is calculated (# 365). Next, the predicted shake amounts in the horizontal and vertical directions are converted into target angular positions in the horizontal and vertical directions, and the temperature is corrected. After that, it returns. As a result, the target angle positions in the horizontal and vertical directions subjected to the temperature correction are set in the drive control circuit 61 as the setting data SD _PH and SD _PV , and each lens of the correction lens unit 3 causes the subject image shake due to camera shake to occur. Drive to correct.

In this embodiment, the shake detection accuracy is as follows.
Although it is used for switching parameters, the present invention is not limited to this, and it may be used for determining whether or not to use the shake detection result. That is, if the shake detection accuracy is high, the shake detection result may be used, and if not, the use of the shake detection result may be prohibited. Alternatively, if the shake detection result is high, the shake correction may be performed with the predicted shake amount, and if not, the shake correction may be performed with the shake amount.

In this embodiment, the shake detection accuracy is:
Although it is determined from the shake acceleration change, the invention is not limited to this, and it may be determined from the shake speed change (= shake acceleration). In this case, at least two shake amounts are required to calculate the shake speed, and thus at least three shake amounts are required to determine the change in the shake speed. If the integration period is assumed to be constant, it is possible to simplify the arithmetic expression for calculating the change in the shake speed, similarly to the change in the shake acceleration.

In the present embodiment, the first and second parameters are used. However, the present invention is not limited to such two kinds of parameters, and three or more kinds of parameters may be used. You may. If you do this,
It is possible to obtain a predicted shake amount in accordance with the accuracy.

Further, in the present embodiment, the shake detection accuracy is obtained from the change in shake acceleration, and the shake detection accuracy is compared with a predetermined evaluation reference value to obtain the evaluation of the shake detection accuracy. However, the accuracy of the shake detection may be determined according to the contrast of the subject image captured by the shake sensor 42.

In a shake detection system using a CCD, such as the shake sensor 42, the accuracy of shake detection depends on the contrast of a subject image captured by the CCD. That is, if the contrast of the subject is high, the shake detection accuracy is high,
If the contrast of the subject is low, the shake detection accuracy is low. Therefore, even if the amount of shake is not used, if the contrast of the subject is used, the accuracy of shake detection can be evaluated.

Therefore, for example, a contrast value is calculated from the detection result of the shake detecting section 4, a plurality of calculated contrast values are averaged, and the averaged contrast value is compared with a predetermined value. Accuracy can be determined. At this time, if the averaged contrast value is larger than a predetermined value, the shake detection accuracy is evaluated as high, and if smaller than the predetermined value, the shake detection accuracy is evaluated as low.

[0143]

As is apparent from the above description, according to the first aspect of the present invention, it is possible to execute appropriate shake correction according to the shake detection accuracy and to prohibit use of the shake detection result when the accuracy is poor. Becomes possible.

According to the second aspect of the present invention, it is possible to select a plurality of shake amounts for calculating a predicted shake amount suitable for shake detection accuracy. This makes it possible to execute shake correction that matches the shake detection accuracy.

According to the third aspect of the present invention, the value of the term of the shake acceleration (the degree of use of the predicted shake amount) according to the shake detection accuracy.
Can be increased or decreased. This makes it possible to execute shake correction that matches the shake detection accuracy.

According to the fourth and fifth aspects of the present invention, it is possible to execute shake correction that matches shake detection accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a perspective view of a vertical shake correction lens and the like stored in a lens barrel.

FIG. 3 is a diagram illustrating an example of a shake detection area covered by a shake detection unit.

FIG. 4 is a block diagram illustrating a configuration of a shake amount detection unit.

FIG. 5 is an explanatory diagram of shake amount data selection and extraction by a data selection unit.

6A is a diagram illustrating a state of a deviation including a deviation due to a failure in mounting a shake sensor, and FIG. 6B is a diagram illustrating a state of a deviation not including the deviation factor.

7A is a diagram illustrating a shake detection result when the variation is large, and FIG. 7B is a diagram illustrating a shake detection result when the variation is small.

8A is a diagram illustrating the influence of an error in a shake amount selectively extracted using a first parameter Tv, and FIG. 8B is a diagram illustrating an error in a shake amount selectively extracted using a second parameter Tv. FIG.

FIG. 9 is a graph of a simulation of shake correction accuracy using G and a second parameter.

10A is a diagram showing the evaluation reference value of FIG. 9 as specific numerical values, and FIG. 10B is a graph of a simulation of shake correction accuracy obtained from a change in shake speed.

FIG. 11 is a block diagram showing an example of a drive control circuit forming a part of a servo circuit.

FIG. 12 is a temperature characteristic diagram of a motor torque which is a factor of a change in drive characteristics.

FIG. 13 is a configuration diagram of a horizontal position detection unit.

FIG. 14 is a block diagram of a horizontal position detection unit.

FIG. 15 is a control flowchart executed by the microcomputer.

FIG. 16 is a flowchart of a subroutine of a “shake correction sequence”.

FIG. 17 is a flowchart of a subroutine of “detection accuracy calculation processing”.

FIG. 18 is a flowchart of a “parameter set” subroutine.

FIG. 19 is a flowchart of a subroutine of “prediction calculation”.

FIG. 20 is a flowchart of a subroutine of “selection and extraction of shake amount”.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 camera 2 imaging unit 3 correction lens unit 4 shake detection unit (shake detection means) 5 shake correction amount setting unit 6 drive unit 7 position detection unit 8 exposure control unit 9 release monitoring unit 10 ranging module 11 focus unit 12 shake display unit Reference Signs List 21 shooting lens 22 film 23 shutter 31 horizontal shake correction lens 32 vertical shake correction lens 41 detection lens 42 shake sensor 43 shake sensor control unit 44 signal processing unit 51 shake amount detection unit (shake amount detection means) 52 coefficient conversion unit 53 target Position setting unit 54 Correction gain setting unit 55 Temperature sensor 56 Memory 57 Position data input unit 58 Timer 61 Drive control circuit 62 Horizontal actuator 63 Vertical actuator 71 Horizontal position detection unit 72 Vertical position detection unit 511 Shake amount calculation unit (vibration amount detection means ) 512 Data selection unit 513 Predicted shake amount calculation unit (Estimated shake amount calculation means) 514 Evaluation setting section 514a Detection accuracy calculation section 514b Detection accuracy evaluation section (evaluation means) 514c Parameter setting section (parameter setting means)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuhiko Yukawa 2-3-1-13 Azuchicho, Chuo-ku, Osaka City Inside Osaka International Building Minolta Co., Ltd. (72) Keiji Tamai 2-3-3 Azuchicho, Chuo-ku, Osaka City 13 Osaka International Building Minolta Co., Ltd. (72) Inventor Masatoshi Yoneyama 2-3-13 Azuchicho, Chuo-ku, Osaka City Osaka International Building Minolta Co., Ltd.

Claims (5)

[Claims] 1. A shake detecting means for periodically detecting a shake of a camera body with respect to a subject, a shake amount detecting means for detecting a shake amount from a detection result of the shake detecting means, and a plurality of shake amounts obtained from the shake amount detecting means. Evaluation means for evaluating the shake detection accuracy of the shake detection means using the amount of shake, parameter setting means for setting a parameter in accordance with the evaluation result, and prediction for calculating a predicted shake amount using the set parameters. A camera with a shake correction function comprising a shake amount calculating means. 2. The camera with a shake correction function according to claim 1, wherein the parameter is a shake detection time interval for determining a selection condition of a plurality of shake amounts used in the prediction calculation. 3. The predicted shake amount calculating means calculates a shake speed and a shake acceleration using a plurality of shake amounts, and performs a shake prediction using an arithmetic expression having the shake speed and the shake acceleration. The camera with a shake correction function according to claim 2, wherein the parameter is a coefficient applied to the shake acceleration term. 4. The shake detection time interval as the parameter has a first time interval and a second time interval longer than the first time interval, and the parameter setting means determines the shake detection accuracy. The method according to claim 2, wherein when the evaluation is high, the first time interval is set as the parameter, and when the evaluation of the shake detection accuracy is low, the second time interval is set as the parameter. Camera with shake correction function. 5. The coefficient, which is a parameter, includes a first coefficient and a second coefficient smaller than the first coefficient. Setting a first coefficient as the parameter;
4. The camera with a shake correction function according to claim 3, wherein the second coefficient is set as the parameter when the evaluation of the shake detection accuracy is low.