JPH1184448A - Camera with shake correcting function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera with a shake correcting function capable of reducing a detection error by a shake detection means. SOLUTION: This camera is provided with an averaging processing part 511d calculating an averaged shake amount at an intermediate time point from respective two continuous shake amounts as for the respective shake amounts in the lateral and longitudinal directions obtained by an image comparison arithmetic part 511c. By the effect of this averaging processing, the dispersion in detection of the shake detection part is rounded off. Thus, the predictive shake amount close to the more actual shake amount can be obtained by using the shake amount averaged by the processing part 511d rather than by using the shake amount obtained by the arithmetic part 511c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera with a shake correcting function for correcting a relative shake between a camera body and a subject image caused by camera shake during photographing.

[0002]

2. Description of the Related Art In recent years, using a CCD or the like, a shake amount between a subject and an image pickup optical system caused by camera shake or the like has been detected.
Video cameras, electronic still cameras, and the like having a function of correcting the shake amount so as to cancel them are on the market, and those applied to the camera have been proposed.

Japanese Patent Application Laid-Open No. 8-51566 discloses a technique for detecting a shake amount by capturing a subject image using a solid-state image pickup device such as a CCD provided for shake detection, and for canceling the shake amount from the detection point. A camera with a shake correction function that drives the correction optical system by using the predicted shake amount to predict a shake amount in consideration of arithmetic processing and time required for driving of the correction optical system. Are listed.

[0004] Although it is not a prediction of a shake amount such as a hand shake, there has been proposed a technique of predicting a moving object for obtaining an optimum focus. For example, Japanese Unexamined Patent Publication No. Hei 3-226723 discloses that using the latest five defocus amounts,
The three velocities are calculated by simple averaging at intervals of two, and if the average velocities calculated in this way become four or more, these four average velocities are further simply averaged, and a quadratic curve approximation is performed. A prediction is disclosed that uses the result of the calculation as the final speed.

Japanese Patent Laid-Open Publication No. 1-140109 proposes a prediction of a moving object following mode in automatic focus adjustment. The prediction includes a detected defocus amount and a detected defocus amount. The speed obtained by multiplying the average with the defocus amount by １ ／ is used. If the signs of the three most recent data obtained by the three detections do not match and the signs of the two most recent data obtained by the two detections do not match, the average of the three data is used. Prediction of an average mode for driving an imaging optical system has also been proposed.
In this automatic focus adjustment, the focus is locked if focus detection cannot be performed twice consecutively, and if the focus is recovered once, the missing data is subtracted from the defocus amount before and after that to compensate for the undetected and missing data. Is calculated by the average.

Further, Japanese Patent Application Laid-Open No. 63-5316 discloses that
A prediction of a moving object following mode in automatic focus adjustment has been proposed. In this prediction, in order to reduce an error generated at the time of focus detection, a moving amount of a subject per unit time, that is, a speed is set to be larger for new data. The speed obtained by averaging with weights is used.

Japanese Patent Application Laid-Open No. Sho 60-214325 further includes a detecting means for detecting a defocus amount and a movement detecting means for detecting a movement of a target object based on the output. There is disclosed an apparatus in which the focus is corrected momentarily by the output of the movement detecting means, and an image forming lens is driven based on the corrected defocus amount to perform automatic focus adjustment. Among them, the defocus amount at the center of the integration time is obtained by averaging the defocus amounts on both sides irrespective of the presence or absence of prediction. Although not specified, it is necessary to use a weighted average in order to calculate the central value of the charge accumulation time to be used.

[0008]

In the above-described conventional camera for correcting camera shake and the like, data at predetermined intervals is selected from a plurality of recently detected data, and prediction is performed using the selected data. Therefore, there is a problem that the prediction includes a detection error by the shake detection system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a camera with a shake correction function capable of reducing a detection error by a shake detection means.

[0010]

According to the present invention, there is provided a vibration detecting means for periodically detecting a relative vibration amount between a camera body and a subject image; Among the detected shake amounts at a plurality of times in the past, averaging means for calculating an average shake amount using a continuous detected shake amount, and using the average shake amount and a recent detected shake amount,
The image processing apparatus further includes a prediction calculation unit that predicts a current shake amount, and a shake correction unit that corrects a relative shake between the camera body and the subject image by the predicted shake amount obtained by the prediction calculation unit.

In this configuration, since the detected shake amount is averaged by the averaging means, a detection error by the shake detection means is reduced by the averaging process.

[0012]

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, and a position detection unit 7.

The photographing unit 2 includes a photographing lens 2 having an optical axis L.
1, and an unillustrated mechanism for feeding the loaded film 22 to an image forming position on the optical axis L, 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 detecting section 4 shown in FIG. 1 includes a detecting lens 41, a shake sensor 42, a shake sensor control section 43, and a signal processing section 44, and is caused by a relative shake of the camera 1 main body with respect to a subject. This is to obtain image data for detecting subject image shake. The detection lens 41 has an optical axis parallel to the optical axis L of the photographing lens 21, and forms a subject image on a 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, receives a subject image formed by the detection lens 41, and obtains an electric signal corresponding to the amount of received light. Things. 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).
The image signal obtained by each light receiving operation is transmitted to the signal processing unit 44. The signal processing unit 44 includes the shake sensor 42
A predetermined signal processing (processing such as signal amplification and offset adjustment) is performed on each pixel signal from
D conversion is performed.

The shake correction amount setting unit 5 includes a shake amount detection unit 5
1. A coefficient conversion unit 52, a target position setting unit 53, a correction gain setting unit 54, a temperature sensor 55, a memory 56, and a position data input unit 57, which generate shake correction data for shake correction driving. . The temperature sensor 55 detects the environmental temperature of the camera 1.
The memory 56 includes a RAM that temporarily stores image data used by the shake amount detection unit 51 and data such as the amount of shake,
RO for storing conversion coefficients and the like used in coefficient conversion section 52
M.

FIG. 3 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, and a predicted shake amount calculation unit 513, calculates a shake amount using image data from the signal processing unit 44, and uses the shake amount. Thus, the predicted shake amount is further obtained.

The shake amount calculating section 511 includes an image data dumping section 511a, an image comparing / calculating section 511c, and an averaging section 511d. Image data dump unit 5
11a stores image data from the signal processing unit 44 in the memory 5;
6 (RAM).

The image comparison / calculation unit 511c calculates the amount of shake using the image data dumped in the memory 56 and the reference image.

The calculation processing for obtaining the shake amount will be described. First, the image comparison calculation unit 511 c
From the image data dumped, a target image is extracted for each block of a required area (indicated by a broken line in FIG. 4), and a block B including an image having feature points and the like is extracted from the reference image. To be selected. At the time of this selection, each lens of the correction lens unit 3 is fixed to a predetermined reference position, for example, a center position (a position where Ra = Rb in FIG. 2) where each lens can move in the opposite direction by the same distance. 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, is more likely to hit the end.

Next, 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 calculates a pixel based on the amount of change in the reference image position with respect to the reference image position. Calculate the shake amount in several units. The shake amount is determined in each of the horizontal and vertical directions (E
_H [i] and E _V [i]), and are temporarily stored in the memory 56. Where i (i = 0, 1, 2, 3,...)
Indicates a cycle number (corresponding to time since the cycle is known), and the latest shake amounts are E _H [i] and E _V [i] (i = 0).

FIG. 5 is a graph showing the relationship between the amount of shake obtained by the calculation process of the image comparison calculation unit 511c and the average processing unit 511d.
FIG. 6 is a graph of the shake amount obtained by the calculation process of the image comparison calculation unit 511c and the shake amount averaged by the averaging processing unit 511d. The averaging processing unit 511d includes the image comparison calculation unit 51
The averaging process is performed on the shake amount obtained by the calculation process 1c to suppress the variation in detection by the shake detection unit 4. That is, as shown in FIG. 5, the averaging processing unit 511d uses the two consecutive shake amounts (indicated by circles in the figure) to perform averaging at an intermediate time point. The shake amount (indicated by a triangle in the figure) is calculated. Due to the effect of this averaging, variations in the detection of the shake detection unit 4 are suppressed, and the averaging processing unit 51 is used rather than using the shake amount calculated by the image comparison calculation unit 511c.
It is understood from FIG. 6 that the use of the shake amount averaged in 1d is closer to the actual shake amount. The average shake amount is calculated in each of the horizontal and vertical directions (E _H [j], E _V [j]; j =
0, 1, 2, 3,...) Are temporarily stored in the memory 56.

FIG. 7 is a diagram showing the relationship between the shake velocities V1 and V2 and the shake acceleration α used in the predicted shake amount calculator 513, and the shake amount necessary for obtaining these. As shown in FIG. 7, to obtain the shake acceleration α in each of the horizontal and vertical directions, two shake speeds V1 and V
2 are required, and two shake amounts are required to obtain these shake speeds V1 and V2. Therefore, four shake amounts are required to obtain the shake speeds V1 and V2 and the shake acceleration α.

Therefore, in the present embodiment, the data selection unit 5
12 selects and extracts four shake amounts including the latest shake amount from the memory 56 using predetermined reference time intervals (speed calculation time Tv and acceleration calculation time Tα). The latest shake amount (E _H [i], E
_The reason why _V [i]; i = 0) is included is that it has been confirmed by simulation that a better shake prediction can be performed than when no value is included.

FIG. 8 is an explanatory diagram of the selection and extraction of the shake amount by the data selection unit 512. The data selection unit 512 determines the amount of shake (E _H [i], E at the latest time point (i = 0)).
_V [i]; i = 0) is selected and extracted, and a time point (j = 1) longer and shorter than Tv is searched for the latest time point (ta), and this time point (tb) is searched. .) Are selected and extracted (E _H [j], E _V [j]; j = 1). Moreover, searching for the time to be longer and the shortest than Tα against the latest time point ta (j = 3), this point (. To tc) shake amount in _{(E H [j], E} V [j]; j = 3)
Select and extract. Further, a time point (j = 5) that is longer and shorter than Tv with respect to the time point tc is searched, and the shake amount (E _H [j], E at this time point (td)) is searched.
_V [j]; j = 5) is selected and extracted.

Here, the speed calculation time Tv is a separation time for obtaining the shake speeds V1 and V2 with a predetermined accuracy or more, and the acceleration calculation time Tα is a separation time for obtaining a shake acceleration α with a predetermined accuracy or more. is there. As described above, by selectively extracting the shake amount using the reference time, it is possible to perform the shake correction independent of the brightness of the subject, and to obtain the shake correction with a predetermined accuracy by, for example, a simulation or the like. By setting the value to a certain value, appropriate shake correction can be performed on the actual shake. By the way, the calculation processing time of the shake amount detection unit 51 is much faster than the reference times Tv and Tα.

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.

Returning to FIG. 3, the predicted shake amount calculation section 513
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).

The calculation processing for calculating the predicted shake amount will be described. First, the predicted shake amount calculation unit 513
A shake speed and a shake acceleration required for calculating the predicted shake amount are obtained. The way of obtaining this will be described with reference to FIG. 8 as an example. The latest shake amount (E _H [i], E _V [i]; i
= 0) and the averaged shake amount (E _H [j], E
_V [j]; j = 1) to (Equation 1), the deflection speed (V _1H ,
V _1V ) is required.

[0031]

(Equation 1)

Further, the averaged shake amount (E _H [j], E _V [j]; j = 3 and E _H [j], E at the time points tc and td.
_V [j]; j = 5), and the shake speed (V _2H ,
V _2V ) is required.

[0033]

(Equation 2)

Further, the swing speeds (V _1H , V _1V ), (V _2H ,
V _2V ), the shake accelerations (α _H , α _V ) are obtained by (Equation 3).

[0035]

(Equation 3)

Next, the predicted shake amount calculation unit 513 determines the latest shake amount (E _H [i], E _H) based on the assumption that the shake due to the hand shake changes substantially according to the uniform acceleration motion.
_V [i]; i = 0), the shake speeds (V _1H , V _1V ) and the shake accelerations (α _H , α _V ) are used to calculate the predicted shake amounts (E _PH , E _PV ) by (Equation 4).

[0037]

(Equation 4)

FIG. 9 is an explanatory diagram of the time T used in the above-mentioned equation (Equation 4) for calculating the predicted shake amount. In the present embodiment, the prediction calculation is performed at the intermediate time point t1 of the integration time (T1) assuming that the shake detection by the shake detection unit 4 has been performed. In this case, from the intermediate time point t1, the second half time (T1 / 2) of the integration time T1, the time required for transferring the obtained pixel signals (T2), and the time point t2 when the processing time of the prediction operation (T3) has elapsed, or More precisely, at the time t3 when the time (T4) required for actually driving the correction lens unit 3 by the driving unit 6 to complete the shake correction is determined according to the shake amount obtained by the shake detection. Actual shake correction is executed.

In the present embodiment, the predicted shake amount calculator 513
Is the time T = (T1 / 2) + T2 + T3, which is the future direction, based on the time point t1, as shown in (Equation 4).
A prediction calculation for predicting a shake at a time point t3 when + T4 has elapsed is executed.

The time T is calculated within the time T3. The time T1 is obtained from the start time and the end time of the integration, and the time T2 is obtained from the start time and the end time of the transfer. As the time T4, a constant value determined by the design specification of the driving unit 6 is used. Further, time T3 is
Strictly speaking, the value differs depending on the branch of the arithmetic processing process, but the difference is on the order of several to several tens of μs. Therefore, in this embodiment, a predetermined constant value is used.

Further, in the present embodiment, as shown in (Equation 4), a coefficient k (0 <k <1) is included in the acceleration term.

FIG. 10 is a diagram showing the necessity of the coefficient k included in the acceleration term. In the case of the prediction based on the uniform acceleration motion, a very good prediction can be made instantaneously, but the amplitude of the camera shake is not so large, and the acceleration constantly changes, indicating a very complicated motion. In particular, near the vertex of the camera shake waveform, the speed rapidly changes, and the sign thereof also changes. Therefore, in the prediction based on the uniform acceleration motion, the time T
The effect of the acceleration term including the acceleration multiplied by the square of becomes excessive, and the prediction result becomes far from the actual vibration as shown in FIG. For this reason, in the present embodiment, the coefficient k is included in the acceleration term (specifically, the coefficient k is multiplied by the acceleration term of the moving amount calculation formula based on the uniform acceleration motion), and the predicted shake amount (E _PH , E _PV ) is calculated. It is adapted to the actual swing. The coefficient k is desirably about 0.5 as confirmed by simulation.

Returning to FIG. 1, the coefficient conversion unit 52 calculates the horizontal and vertical predicted shake amounts using the conversion coefficients stored in the memory 56 and sets 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.

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 these are set in 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 based on 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 configured by a coreless motor or the like (see the motor 632 and the gear 631 in FIG. 2), and perform the horizontal shake correction according to the horizontal and vertical drive signals generated by the drive control circuit 61, respectively. Lens 31 and vertical shake correction lens 3
2 is 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, a motor (FIG. 2)
Of each motor 632), the correction lens unit 3
In addition, the backlash of the drive system (movable mechanism) in the drive unit 6 and the hardness of gears (see the gear unit 322 and the 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 the fluctuation of the driving characteristic due to the horizontal and vertical basic gains in accordance with 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.

Therefore, the drive control circuit 61 includes a buffer, a sample 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 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 of the lateral position detector 71. The addition circuit 607 obtains a difference voltage between the target position voltage V _PV and the output voltage V _V of the vertical position detection unit 72. The adder circuits 606 and 607 add the negative output voltages V _H and V _V output from the horizontal position detector 71 and the vertical position detector 72 to the target position voltages V _PH and V _PV , respectively, to obtain a difference voltage. Seeking.

V / V 608 is for amplifying the input voltage to a voltage as a lateral proportional gain at a preset ratio with respect to the reference temperature, and V / V 609 is for amplifying 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 differentiates the reference temperature by a preset time constant 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 basic gains 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.

The position detecting section 7 shown in FIG. 1 comprises 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 position where the gear portion is formed in one frame 311 (see LED 721 in FIG. 2). Slit 7
Reference numeral 12 is for sharpening the directivity of light emitted from the light emitting unit of the LED 711. The PSD 713 is attached to a position facing the LED 711 on the inner wall side of the lens barrel 24, and outputs photoelectric conversion currents I1 and I2 having values corresponding to the light receiving position (center of gravity position) of the emitted light beam from the LED 711. By measuring the difference between the photoelectric conversion currents I1 and I2, the position of the lateral shake correction lens 31 is detected. The vertical position detection section 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 there is a light receiving position (center of gravity position) at a position that is distance x to the right from the center of PSD 713, length x, current I1,
The light receiving area length L of I2 and PSD 713 satisfies the relationship of (Equation 5).

[0071]

(Equation 5)

Similarly, the length x, the voltages V1 and V2, and the light receiving area length L satisfy the relationship of (Equation 6).

[0073]

(Equation 6)

From this, the value of V2 + V1, that is, the voltage V3
Is controlled to be always constant, the relationship of (Equation 7) 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.

[0075]

(Equation 7)

The shake sensor control unit 43, signal processing unit 44, shake amount detection unit 51, coefficient conversion unit 52, target position setting unit 53, correction gain setting unit 54, and position data input unit 57 perform the above processing. And a MPU (microprocessor unit) for executing the program. Further, each of the above units may be configured by one or a plurality of MPUs.

Next, the operation of the present embodiment will be described. The light arriving from the subject passes through the detection lens 41 and forms an image on the light receiving surface of the shake sensor 42 as a subject image. The subject image is extracted as an image signal from the shake sensor 42 at every integration time under the control of the shake sensor control unit 43. This image signal is converted into image data by the signal processing unit 44.

The image data is dumped into the memory 56, and the horizontal and vertical shake amounts (E _H [i], E _V [i]) are obtained by the arithmetic processing of the image comparing / calculating section 511c, and are averaged. The unit 511d averages the amount of shake determined immediately before, and stores the average in the memory 56.

Thereafter, four shake amounts including the latest shake amount are selectively extracted from the memory 56 in each of the horizontal and vertical directions.

FIG. 15 is a subroutine of "selection and extraction of shake amount". When this subroutine is called, the counter n is set to "1"(# 5), incremented by "1"(# 10), and the time interval T _1n (= t1
−tn) is calculated (# 15). However, at time t1,
8 corresponds to the time point i = 0, and the time point tn (n corresponds to the value of the counter n) corresponds to the time point j in FIG.

Next, it is determined whether or not the time interval T _1n is shorter than Tα (# 20). If the time interval T _1n is shorter than Tα (YES in # 20), the process returns to step # 10. On the other hand, when the time interval T _1n is not shorter than Tα (NO in # 20), the counter m is set to the value of the counter n (# 25). Thus, the value of the counter n is stored, and the search at the time point tc shown in FIG. 8 is completed.

Thereafter, the counter m is incremented by “1” (# 30), and the time interval T _nm (= tn−t)
m) is calculated (# 35). However, the time point tm (m corresponds to the value of the counter m) corresponds to the time point j in FIG.

Next, it is determined whether or not the time interval T _nm is shorter than Tv (# 40). If the time interval T _nm is shorter than Tv (YES in # 40), the process returns to step # 30. On the other hand, if the time interval T _nm is not shorter than Tv (NO in # 40), the counter h is set to "1"(# 45). Thus, the value of the counter m is stored, and the search at the time point td shown in FIG. 8 is completed.

Thereafter, the counter h is incremented by “1” (# 50), and the time interval T _1h (= t1−t
h) is calculated (# 55). However, the time point th (h corresponds to the value of the counter h) corresponds to the time point j in FIG.

Next, it is determined whether or not the time interval T _1h is shorter than Tv (# 60). If the time interval T _1h is shorter than Tv (YES in # 60), the process returns to step # 50. On the other hand, when the time interval T _1h is not shorter than Tv (NO in # 60), the process proceeds to the next data extraction (# 6).
5). At this time, the search for the time point tb shown in FIG. 8 is completed, and this time point tb is specified by the value of the counter h.

In step # 65, the shake amount at time tn specified by the value of counter n when the determination in step # 20 is NO is extracted as the shake amount at time tc shown in FIG. The shake amount at time tm specified by the value of the counter m when the determination in step # 40 is NO is extracted as the shake amount at time td shown in FIG. Further, step # 60
The shake amount at the time th specified by the value of the counter h when the determination of NO is NO
Is extracted as the amount of shake at. Note that the latest time point t1
Is always extracted. Then return.

When the four shake amounts including the latest shake amount are selectively extracted in each of the horizontal and vertical directions, the shake speed and the shake acceleration are obtained from these, and the estimated shake amount is calculated by the calculation of (Equation 4). Is required.

In each of the horizontal and vertical directions, the predicted shake amount is converted into a target angle position (drive amount), subjected to temperature correction, and converted into target position information (drive end position).
The setting data (SD _PH , SD _PV ) is set in the drive unit 6. On the other hand, the setting data SD _GH and SD _GV are set in the drive unit 6 by the correction gain setting unit 54. As a result, the correction lens unit 3 sets these setting data SD _PH , SD
By driving the driving unit 6 according to _PV , SD _GH , and SD _GV , driving is performed so as to correct the relative shake amount between the camera body and the subject image.

In this embodiment, the shake sensor 42
Although a CCD area sensor is used as the above, a sensor using an angular velocity sensor may be used. In this case, since the integration process for detecting the angular velocity requires time, the above-described prediction method can be suitably used.

[0090]

As is apparent from the above, according to the present invention, the detection error by the shake detecting means can be reduced.

[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 block diagram illustrating a configuration of a shake amount detection unit.

FIG. 4 is an explanatory diagram of reference image selection.

FIG. 5 is an explanatory diagram of an averaging process performed by an averaging process unit on a shake amount obtained by a calculation process of an image comparison calculation unit.

FIG. 6 is a graph of a shake amount obtained by a calculation process of an image comparison calculation unit and a shake amount averaged by an averaging processing unit;

FIG. 7 is a diagram illustrating a relationship between a shake speed and a shake acceleration used in a predicted shake amount calculation unit and a shake amount necessary for obtaining the shake speed and the shake acceleration.

FIG. 8 is an explanatory diagram of selection and extraction of a shake amount by a data selection unit.

FIG. 9 is a diagram illustrating a time T used in an arithmetic expression for calculating a predicted shake amount.
FIG.

FIG. 10 is a diagram showing the necessity of a coefficient k included in an acceleration term.

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 one 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 subroutine of “selection and extraction of shake amount”.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 camera 2 imaging unit 3 correction lens unit (vibration correction unit) 4 shake detection unit (vibration detection unit) 5 shake correction amount setting unit 6 drive unit (vibration correction unit) 7 position detection unit (vibration correction unit) 21 imaging lens 22 Film 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 52 Coefficient conversion unit 53 Target position setting unit 54 Correction gain setting unit 55 Temperature sensor 56 Memory 57 Position data input unit 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 512 Data selection unit 513 Prediction amount calculation unit (prediction calculation unit) 511a Image data dump Unit 511c image comparison operation unit 511d averaging processing unit (average Stage)

 ──────────────────────────────────────────────────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 (1)

[Claims] 1. A shake detecting means for periodically detecting a relative shake amount between a camera main body and a subject image, and a shake amount detected at a plurality of past times detected by the shake detect means.
An averaging unit that calculates an average shake amount using a continuous detected shake amount; a prediction calculation unit that estimates a current shake amount using the average shake amount and a recently detected shake amount; and the prediction calculation unit. A camera with a shake correction function, comprising: shake correction means for correcting the relative shake between the camera body and the subject image by the obtained estimated shake amount.