JPH05181180A - Device and method for detecting breakage of acceleration sensor of camera provided with camera shake correction function - Google Patents

Abstract

PURPOSE:To effectively and properly correct camera shaking to prevent a blurred picture caused by the camera shaking and to display a warning that the correction of the camera shaking is impossible in the case that an accelera tion sensor which detects the camera shaking is broken by a large impact. CONSTITUTION:Detection data Ak obtained by the acceleration sensor 6a is inputted in a decision circuit 27 and also stored in a memory 29. When the stored data is not fluctuated for a specified time, that the sensor 6a is broken is judged, and the result is displayed to be warned on a display unit 28. When the circuit 27 decides that the sensor 6a is normal, the data Ak is sampled by a sampling circuit 6b to obtain a blurring correction driving amount by an arithmetic circuit 10. A blurring correction actuator 9 is driven in accordance with the blurring correction amount to drive an optical member for correcting blurring 5 so as to negate the camera shaking. Therefore, the picture which is not blurred is obtained, and that the correction is not performed when the sensor 6a is broken is recognized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting damage to an acceleration sensor of a camera with a camera shake correction function and a method for detecting the same, and more specifically, detecting camera shake occurring in a camera body and based on the detected value at this time. A camera with a camera shake correction function that drives a correction optical member inserted in the optical path of the shooting optical system to cancel the image movement on the film surface and detect the destruction of the acceleration sensor that detects camera shake. The present invention relates to an acceleration sensor destruction detection device and a destruction detection method thereof.

[0002]

2. Description of the Related Art Generally, a camera with an image stabilization function (hereinafter abbreviated as "camera") is integrated with a camera body as shown in FIG. , Or a photographic optical system 1 is detachably provided via a lens mount, and a film surface 2 is located behind the optical axis O thereof.

The photographing optical system 1 has a focus lens group 3 formed of a plurality of lenses and a zoom lens group 4 formed of a plurality of lenses, and a correction optical member 5 is provided in this optical path. Has been inserted.

Then, the focus lens group 3 is driven in focus by a focus command signal Df which is an output of a control circuit (not shown), and the zoom lens group 4 is driven by the zoom command signal Dz.
Zooming is performed by the camera, and the correction optical member 5 is driven by the camera shake correction command signal Da.

Next, a specific form of the camera shake correction command signal Da will be described. If the vibration of the camera shake that occurs in the camera body has a substantially sinusoidal characteristic a that moves in the ± directions with the amplitude of 0 as shown in FIG. 17, in order to correct the camera shake, first install it in the camera body. The camera shake detection unit detects the speed V in an extremely short period, calculates the camera shake change amount data B _k on the basis of the detection data at this time, and obtains it, and the camera shake correction command signal based on the camera shake change amount data B _k. Da
The image movement on the film surface 2 is eliminated by driving the correction optical member 5 in the direction in which the movement due to the camera shake is canceled.

However, the corrected motion is always delayed as indicated by the symbol b. That is, as shown in an enlarged view in FIG. 18, the blurring detection values t-2It, t-It, and t + It (where It: integration time at each time) are detected a plurality of times based on the blurring detection value obtained at each time. Change amount data B _k , B _k-1 are obtained, camera movement speed data V _k , V _k-1 are obtained from the shake change amount data B _k , B _k-1 , and these data V _k ,
The camera shake correction command signal Da is generated based on V _k-1 .

Therefore, the movement of the image on the film surface is the corrected characteristic f when it is corrected by the correction amount characteristic d with respect to the blur amount characteristic e as shown in FIG. For this reason, as the camera shake correction, only an improvement effect of about 1/4 of the camera shake amount of the camera body can be obtained.

In order to improve this, there is a method in which the input to the drive circuit to the correction optical member is controlled so as to converge the vibration of the camera shake of the camera body when driving the correction optical system.

Specifically, for example, Japanese Patent Laid-Open No. 1-30022.
As disclosed in Japanese Patent Laid-Open No. 1-58, the amplification factor of the drive circuit to the correction optical member is changed according to the output of the shake detection unit, that is, it is changed so as to converge the camera shake vibration of the camera body. There is something.

Further, as described above, as another means for converging camera shake vibration using the electric means, that is, the means for varying the amplification factor of the drive circuit, as disclosed in the publication, a camera is used. In some cases, the shake correction is improved by varying the rigidity of a vibration sensor for detecting the shake of the main body so as to converge the shake vibration.

Further, in Japanese Patent Laid-Open No. 63-8628, the vibration acceleration resulting from camera shake is integrated and converted into a velocity, and a compensation signal for movement control of a lens system (velocity signal for image stabilization) is provided. ) Is output, when only the signal derived from the vibration of the camera shake is input, high-precision image stabilization control can be performed, and when non-target signals other than the camera shake are mixed, this A vibration detection device for a camera is disclosed in which an inconvenient control operation due to a mixed signal is not performed.

That is, in the case of this publication, an acceleration signal obtained corresponding to camera shake vibration is input to an integrating circuit and integrated to convert it into a speed signal, and this speed signal is calculated as a moving average calculating means. To continuously calculate the moving time average value over a predetermined time, detect the difference between these speed signals and the moving time average value by the difference detection means, and use this difference as the image blur compensation signal of the camera. It was done.

By the way, in the conventional camera, since the correction optical member is driven based on the result of the calculation, the following problems occur. That is, since the camera shake detection is performed, the drive amount of the correction optical member is calculated based on the detection result, and the correction optical member is driven based on the result of this calculation, the following problems occur. ing.

That is, although a time delay (see reference numeral c in FIG. 17) inevitably occurs between the camera shake detection time point, the calculation end time point, and the driving time point, camera shake is improved to some extent. There is a drawback in that the amount of undercorrection always occurs due to the delay that occurs in the image stabilization system.

Even with such a conventional system, when the absolute amount of camera shake that occurs in the camera is relatively small, the amount of undercorrection is also small, so that the correction means in the conventional apparatus has a substantial problem. Although it does not occur, a large amount of insufficient correction always occurs when the absolute amount of camera shake is large.

Further, in the case of the above-mentioned Japanese Patent Laid-Open No. 63-8628, high accuracy image stabilization control can be realized when only a signal derived from the vibration of a camera shake is input.
When a signal derived from a slight vibration other than camera shake is mixed, it is not possible to appropriately deal with the problem, and the captured image may be substantially the same as the case of shooting due to camera shake.

On the other hand, an acceleration sensor is generally used as the camera-shake detecting means used in conventional camera-shake preventing cameras. FIG. 20 is a cross-sectional view of a main part of an acceleration sensor formed of a resistor that converts a displacement amount into an electric amount. A layer 102 is formed by sputtering or the like on a substrate 101 made of a hard material such as a glass plate. The thin layer 103 is formed as a thin film on the upper surface of the layer 102.

Then, a part of the layer 102 is removed by, for example, etching to form a space 104, and a shake mass (weight) 105 is formed. The base end portion of the displacement mass 105 is cantilevered at the portion of the thin layer 103 in which the resistor 106 is formed as a semiconductor strain gauge, and the free end of the stopper portion 107 that cuts and exposes the thin layer 103. It is located with a gap maintained with respect to the gap portion 108 formed at the tip.

Therefore, if the substrate 101 side of the acceleration sensor as shown in FIG. 20 is fixed to the camera body, the shake mass 105, which is cantilevered by the resistor 106, is displaced along with the acceleration generated in the camera body. To do. Then, the resistor 106 is deformed into a curved shape, and the resistance value changes according to the deformation. This change in resistance value can be taken out as a shake detection output.

The blurring detection output generated in this manner is such that the tip of the blurring mass 105 (the tip of the free end in the cantilevered support by the resistor 106) is generated when the camera body is subjected to an acceleration equivalent to a normal camera shake. Since it is set so as not to hit the stopper portion 107, an accurate shake detection output can be obtained. Further, when an acceleration exceeding the normal hand shake occurs in the camera body, the tip of the shake mass 105 abuts on the stopper portion 107.

Ordinary camera shake is the largest during camera holding, and the acceleration at this time was measured using an acceleration sensor. The results shown in FIG. 21 were obtained.

That is, the value of the acceleration G is from +0.25 to-
The output is + 0.2V to -0.2V for 0.25
When the acceleration is continuously measured by using an acceleration sensor that linearly corresponds to the voltage, the camera shake characteristic RI during camera holding has a fluctuation range of about 0.026 G as shown in the figure, whereas The fluctuation range of the camera shake characteristic R2 before and after the switch-on was 0.08 G as shown in the figure. Therefore, it can be seen that the fluctuation range when the release switch is turned on is about three times as large as when the camera is simply held.

In such an acceleration sensor, when a large impact is applied to the camera body, for example, when the camera body is dropped, a strong acceleration is applied to form the resistor 106 serving as a cantilever support portion. The thin film portion is broken. The output of the acceleration sensor after destruction of the acceleration sensor does not change even when acceleration is applied, and shows a constant value.

If the acceleration sensor is destroyed, even if the camera shake amount of the camera body is calculated, the correct shake amount value cannot be calculated. Therefore, it becomes impossible to correctly correct the fluctuation of the image on the film surface due to the camera shake.

Therefore, it becomes necessary to detect the breakage of the acceleration sensor. JP-A-2-212252 proposes a failure detection device for such an acceleration sensor.

In the acceleration sensor failure detection device disclosed in this publication, the acceleration sensor control mechanism provides the first
In the failure determination means, it is determined whether or not the output obtained from the acceleration sensor that is set to the above state is the first output, and the acceleration sensor control mechanism is set to the second state. The failure determination means determines whether or not the output obtained from the acceleration sensor is the second output.

Then, the judgment result by the failure judging means is
The output, which is supposed to be obtained when the acceleration sensor is functioning normally and is assumed to be in the first state, is the first output, and is also assumed to be in the second state. When the output of 1 is not the determination result of the second output, the failure determination means is configured to detect that the acceleration sensor has a failure.

[0028]

However, in the conventional failure detection device for an acceleration sensor, a failure detection device for an acceleration sensor, which detects an extremely small camera shake occurring in the camera body when detecting the acceleration generated in the vehicle. As such, it cannot be applied as it is.

By the way, when the camera is provided with an acceleration sensor and camera shake of the camera is detected, a measurement result as shown in FIG. 21 is obtained. In FIG. 21, the horizontal axis represents time (SEC)
Is shown and the vertical axis shows the outputs (V) and (G) of the acceleration sensor, and shows the actual measurement results during photometric holding and before and after the release is turned on. What can be seen from the characteristic curve R1 in FIG. 21 is that the output of the acceleration sensor constantly fluctuates even during photometric holding. This is because the human body is constantly moving in a cycle of about 10 Hz.

Further, from the characteristic curve R2 of FIG. 21, when the release is turned on, unintentional force is applied when the user of the camera presses the release button, and the operating force of the actuator for operation is added when the release switch is turned on. It can be seen that the acceleration increases as a result.

When correcting the shake of the camera body by the detection output of the acceleration sensor for detecting such an acceleration, as described above, when the acceleration sensor fails, it is impossible to accurately calculate the shake correction amount.

As one method for preventing failure of the acceleration sensor, a method of manufacturing the acceleration sensor itself so as to withstand a large acceleration generated when the camera is dropped, that is, shown in FIG. Taking the case of an acceleration sensor as an example, it is conceivable to increase the strength of the cantilevered portion of the resistor 106 to prevent the destruction.

However, such a measure cannot be a solution at all because the amount of displacement at the portion of the resistor 106 becomes small and the detection sensitivity is lowered.

The present invention has been made in order to solve the above-mentioned problems, and the purpose thereof is to be able to surely recognize the breakage of the acceleration sensor and to let the photographer recognize the breakage of the acceleration sensor. An object of the present invention is to provide an acceleration sensor destruction detection device for a camera with a camera shake correction function and a destruction detection method thereof, which can prevent shooting failure due to camera shake.

[0035]

In order to achieve the above object, the invention described in claim 1 is a photographing optical system for correcting the movement of the image position on the film surface caused by the camera shake of the camera body. A correction optical member that is inserted in the optical path of, a shake correction actuator that moves or tilts the correction optical member in a required direction, and an acceleration sensor that detects camera shake of the camera body and converts it into an electric signal. , The film surface caused by the camera shake of the camera body based on the current camera shake detection data detected by the acceleration sensor and the previous camera shake detection data to correct the movement of the image position on the film surface due to the camera shake of the camera body. A calculation means for calculating the shake correction data for correcting and predicting the movement of the image position above, and the camera shake detection data detected by the acceleration sensor is monitored. Then, when the camera shake detection data is about the same for a predetermined time, a determination unit that determines that the acceleration sensor is abnormal, and an alarm that issues an acceleration sensor abnormality alarm when the determination unit determines that the acceleration sensor is abnormal And a display means.

According to a second aspect of the present invention, the determination means samples the camera shake detection data output from the acceleration sensor for a predetermined period and outputs the sampled data to the storage means, and the sampling value stored in the storage means is predetermined. When the time is equal to or longer than the time, the acceleration sensor is determined to be abnormal.

According to a third aspect of the present invention, there is provided a correction optical member which is inserted in the optical path of the photographing optical system to correct the movement of the image position on the film surface caused by the camera shake of the camera body. A shake correction actuator that moves or tilts the correction optical member in a required direction, an acceleration sensor that detects camera shake of the camera body and converts it into an electric signal, and an image position on the film surface due to camera shake of the camera body. Shake correction for correcting and predicting the movement of the image position on the film surface due to the camera shake of the camera body based on the current camera shake detection data detected by the acceleration sensor and the previous camera shake detection data to correct the movement. The analog voltage between the calculation means for calculating data and each resistance of the acceleration sensor configured by connecting the displacement / electricity conversion resistance in a bridge is digitized. An analog / digital converting means for converting into a voltage and a judging means for judging whether or not the acceleration sensor is abnormal by comparing each digital voltage output from the analog / digital converting means, and this judging means is the acceleration sensor. The present invention is characterized by including an alarm display means for issuing an alarm of an abnormality of the acceleration sensor when an abnormality is judged.

According to a fourth aspect of the invention, the movement of the image position on the film surface due to the camera shake of the camera body is corrected and predicted based on the detection data of the camera shake of the camera body detected by the acceleration sensor and the previous camera shake detection data. The shake correction data for calculating the shake correction data is calculated, and the shake correction actuator is driven by this shake correction data to move or tilt the correction optical member inserted in the optical path of the photographing optical system of the camera body in the required direction. Then, the movement of the image position on the film surface caused by the camera shake of the camera body is corrected, the camera shake detection data of the acceleration sensor is monitored by the determination means, and if the camera shake detection data is the same for a predetermined time, the acceleration sensor is detected. Is judged to be abnormal and an alarm is displayed.

Further, in the invention described in claim 5, the movement of the image position on the film surface due to the camera shake of the camera body is detected based on the detection data of the camera shake of the camera body detected by the acceleration sensor and the previous camera shake detection data. The shake correction data for correction prediction is calculated, and the shake correction actuator is driven by this shake correction data to move the correction optical member inserted in the optical path of the photographing optical system of the camera body in the required direction. Or, by tilting the camera, the movement of the image position on the film surface caused by camera shake is corrected, and the analog voltage between the resistors of the acceleration sensor configured by connecting the displacement / electricity conversion resistors in a bridge The digital converting means converts it into a digital voltage, and the judging means compares and judges each digital voltage based on predetermined judging conditions. When it is determined that the acceleration sensor is abnormal Te is obtained by characterized in that the alarm display by the warning display means.

[0040]

The destruction detecting device and the destruction detecting method for an acceleration sensor having a camera shake correction function, which are configured as described above, use a photographing optical system for correcting the movement of the image position on the film surface caused by the camera shake of the camera body. When driving the shake correction actuator that moves or tilts the correction optical member inserted in the optical path of the system in the designated direction,
The camera shake of the camera body is detected by the acceleration sensor, converted into an electric signal, and the camera shake detection data is sent to the calculation means.

The calculating means calculates shake correction data for correcting and predicting the movement of the image position on the film surface due to the shake of the camera body based on the current shake detection data and the previous shake detection data. By driving the shake correction actuator based on this shake correction data, the correction optical member inserted in the optical path of the shooting optical system of the camera body is moved or tilted in the required direction, and the film surface caused by camera shake of the camera body Correct the movement of the image position above.

On the other hand, the camera shake detection data obtained from the acceleration sensor is monitored by the judging means prior to the photographing operation. As a result of the monitoring, when the camera shake detection data becomes the same level for a predetermined time or longer, or when the output of each part forming the acceleration sensor for obtaining the camera shake detection data does not maintain the predetermined relationship, the acceleration sensor is destroyed. It is determined that an abnormality has occurred, the abnormality determination result is output to the display unit, and an alarm is displayed to let the photographer recognize the abnormality (destruction) of the acceleration sensor.

[0043]

Embodiments of the present invention will be described below in detail with reference to FIGS. In FIG. 1, which shows the circuit configuration of the first embodiment of the present invention, the light of an image pickup optical system 1 that is integrated with the camera body as seen in a compact camera, or is detachably provided via a lens mount or the like. The film surface 2 is located on the axis O.

This photographing optical system 1 has a focus lens group 3 formed of a plurality of lenses, a zoom lens group 4 formed of a plurality of lenses, and optical axes of these two lens groups 3 and 4. It is composed of a correction optical member 5 for correcting according to camera shake. Further, the camera body is provided with a camera shake detection unit 6.

The camera-shake detecting section 6 includes an acceleration sensor 6a.
And a sampling circuit 6b for sampling this output, a semiconductor type acceleration sensor is used as the acceleration sensor 6a, and the sampling circuit 6b performs sampling every predetermined time.

FIG. 2 is a circuit diagram of the acceleration sensor 6a, and the illustrated embodiment illustrates the case where the acceleration sensor as shown in FIG. 20 is used. In FIG. 2, the acceleration sensor includes four resistors 202 to 205.
It has a bridge circuit consisting of. In this bridge circuit, a stabilized power supply 2 in which a voltage between a power supply + E and a ground terminal G is supplied to a connection point between the resistors 202 and 205.
01 is connected to the positive output terminal of the acceleration sensor 203 and 2
The connection end of 04 is connected to the ground end G.

The camera shake detection data appears between the connection point between the acceleration sensors 202 and 204 and the connection point between the acceleration sensors 203 and 205, and is output to the signal processing circuit 206. The signal processing circuit 206 includes a temperature compensating circuit, an amplifying circuit, and the like, and outputs the camera shake detection data A _k as described later. This camera shake detection data is the output of the acceleration sensor 6a shown in FIG.

On the other hand, each of the focus lens group 3 and the zoom lens group 4 has a focus motor 7 and a zoom motor 8 for electrically focusing and zooming.
The correction optical member 5 is provided with a shake correction actuator 9 for driving the correction optical member 5 in a direction orthogonal to the optical axis O.

The output end of the acceleration sensor 6a is
It is connected to the input end of the sampling circuit 6b, and the output end of the sampling circuit 6b, that is, the output end of the camera shake detection unit 6 is connected to the input end of the arithmetic means 10, and the arithmetic means 10 has the storage means 11. It is connected.

Further, a focus drive circuit 12, a zoom drive circuit 13, and an actuator drive circuit 14 are connected to each of the focus motor 7, the zoom motor 8, and the blur correction actuator 9.

Further, a CPU 15 for issuing a command for compositely controlling the respective parts provided in the camera body is provided, and the CPU 15 has an AF circuit 16 for distance measurement and automatic focusing drive. Are connected.

The output end of the AF circuit 16, that is, the sending end of the object distance data Dx, is the AF data conversion circuit 1.
This AF data conversion circuit 1 is connected to the first input terminal 7
The output terminal 7 of the focus driving data Dfx is connected to the first control terminal of the focus driving circuit 12.

The second control end of the focus drive circuit 12 is connected to the output end of a photo interrupter 18 for generating pulse number data Pix according to the rotation of the focus motor 7.

On the other hand, the photographing optical system 1 is provided with a zoom position detecting circuit 19 for obtaining the current focal length position data of the zoom lens group 4, and this zoom position detecting circuit 19 is provided.
Of the zoom position data Zpx is
It is connected to the second control end of the F data conversion circuit 17 and also connected to the first control end of the zoom drive circuit 13 described above. At the second control end of this zoom drive circuit 13, C
The output end of the PU 15, that is, the output end of the zoom drive amount data Z ′ is connected.

Further, a photometric circuit 20 is connected to the CPU 15 so that desired photometric control can be executed. Further, at each input terminal of the CPU 15,
A release switch 21 for activating the release, a photometric switch 22 for starting photometry, and a zoom switch 23 for performing zooming are also connected.

Further, a feeding motor 24 for performing a series of operations such as film winding and shutter charging is provided, and the feeding motor 24 is provided with a feeding drive circuit 25 connected to the output end of the CPU 15. The rotation is controlled according to the feeding command from the CPU 15.

Reference numeral 26 is a memory for temporarily storing fixed data for causing the CPU 15 to execute a predetermined program and data required for various controls.

Now, the basic configuration of the above-mentioned arithmetic means 10 is
The first, second and third arithmetic circuits 10a, 10b and 10c are sequentially connected in series, and the storage means 11 has a first memory 11a and a second memory 11b.

The above-mentioned first arithmetic circuit 10a uses V _k = f (V _k-1 , B _k , B _k-1 ) where V _k : (current) camera moving speed data V _k-1 :( and requests the previous) camera moving velocity data B _k :( this time) shake variation data B _k-1 :( last) shake variation data.

The second arithmetic circuit 10b uses the current camera movement speed data V _k and A obtained by the first arithmetic circuit 10a.
The blur correction reference drive data BLwide, that is, BLwide = f (V _k , Dx) is calculated from the subject distance data Dx output from the F circuit 16.

The third arithmetic circuit 10c has a blur correction reference drive data BLwide obtained by the second arithmetic circuit 10b.
The blur correction amount data BLzp, that is, BLzp = f (BLwide, Zpx), is calculated from the zoom position data Zpx obtained by the zoom position detection circuit 19.

On the other hand, the input end of the above-mentioned first memory 11a is connected to the output end of the sampling circuit 6b, that is, the output end of the camera shake detection unit 6, and the output end of the first memory 11a is subjected to the first calculation. It is connected to the first input terminal of the circuit 10a. The output terminal of the first arithmetic circuit 10a is connected to the input terminal of the second memory 11b, and the output terminal of the second memory 11b is connected to the second input terminal of the first arithmetic circuit 10a. There is.

Further, the output end of the acceleration sensor 6a is connected to a determination circuit 27 as a determination means for determining an abnormality (sensor destruction) when the output of the acceleration sensor 6a does not change for a certain time or longer. ing. This determination circuit 2
A memory 29 for detecting a change in the previous data and the current data is connected to 7, and an output end of the determination circuit 27 is connected to a display 28 as a display means for displaying a warning of sensor destruction. ..

Next, a description will be given of the damage detection operation in the damage detection device of the acceleration sensor of the camera with a camera shake correction function according to the present embodiment configured as described above.

Step S1 of the flowchart shown in FIG.
When the main switch is turned on, power is supplied to each part of the circuit, each part of the circuit is initialized to execute a predetermined program stored in the memory 26, and grip hold is detected in the next step S2. A control signal is sent from the CPU 15 to the camera shake detection unit 6, the acceleration sensor 6a and the sampling circuit 6b are activated, and the sampling operation for camera shake detection is started.

Here, the shake variation amount data B _k obtained as the output of the camera shake detection unit 6 is given in a dimension as speed data obtained by integrating the output A _k of the acceleration sensor 6a at the sampling interval St for a certain period It. Be done.

A schematic representation of this situation is shown in FIG. 6, in which the output A _k of the acceleration sensor 6a is n times at a minute sampling interval St from the start point S, for example 32.
When the sampling is performed once and integration is performed for a certain period It, shake variation data as shown in the following equation is obtained.

[0068]

[Equation 1] Sampling performed in this way is started, and then offset data is collected. Here, the reason for obtaining the offset data is that the shake variation amount data B _k corresponding to the camera shake that occurs in the camera body is obtained as the difference from the output A _k of the shake sensor 6a when the acceleration is 0. This is because, for this reason, it is necessary to subtract the offset data Boffset from the outputs B ₁ , B ₂ ... B _k obtained a plurality of times, as shown in the following equation.

[0069]

[Equation 2] In this way, after the offset data is obtained, the process proceeds to the next step S3, and it is determined whether or not the sensor is broken. If NO, the process proceeds to the next step S5, and if YES, the step is performed. In S4, a sensor abnormality warning is displayed. Although these steps S3 and S4 are shown in a simplified manner, the details thereof are performed as shown in FIG.

That is, in step S301 executed after step S2, the previous data Ap is cleared to 0, and the number J of the number of times of data and the number of samplings i in the next steps S302 and S303 are It is cleared to 0 sequentially. In this example, J = 32 and i = 32 are set.

Then, i is incremented in the next step S304, the output A _k of the acceleration sensor 6a is sampled in the next step S305, and the next step S3.
At 06, Bo data for obtaining the offset data Boffset is added, and the routine goes to the subsequent Step S307.

This step S307 determines whether or not the sampling number i has reached 1024, that is, i = 32 and J.
It is determined whether or not the product of 32 (32 × 32 = 1024) has been reached.

If NO in step S307, determination of | Ap-Ao (i) |> C ₃ is performed in step S308. That is, when the absolute value of the difference between the previous data and the current data exceeds the predetermined value C ₃ , it is determined that the sensor is normal because the output of the acceleration sensor has changed, and the next step Move to S312 and clear J to 0,
In the next step S313, the current data Ao (i) is rewritten as the previous data Ap. Then, the process returns to step S304 described above, and steps S304 and S are performed in the same manner as described above.
305, S306, and S307 are sequentially executed.

The execution of these is determined in step S307 as YE.
S, that is, the total number (i) of samplings reaches 1024, and is repeatedly performed until the process proceeds to step S5 shown in FIG.

On the other hand, NO in step S308, that is, the double pair value | A of the difference between the previous data Ap and the current data Ao (i).
When p-Ao (i) | does not reach the predetermined value, it is determined that the output of the acceleration sensor does not fluctuate (step S309).
And the J is incremented, and the next step S31
At 0, the determination of J> C ₄ is made.

If NO in step S310, the process returns to step S304. In this case, it is assumed output variation determined in step S308 that there is no power fluctuation in very little time because the abnormal state that does not exceed the predetermined value C ₃ does not reach the allowable value C ₄ of the number J, acceleration It is assumed that the sensor is not abnormal.

On the other hand, YES in step S310, that is,
J> C _4, that is, | Ap-Ao
(I) When the relation of |> C ₃ exceeds the predetermined number of times C ₄ , it is considered that the acceleration sensor is abnormal because the period in which the output of the acceleration sensor does not fluctuate is long, and a warning is displayed in the next step S311. .. It should be noted that this warning may be displayed and the image stabilization operation may be stopped.

Then, returning to step S5 shown in FIG.
If the release button is pressed halfway and it is NO, until the release button is pressed halfway in step S5,
If the judgment operation is continued and the result is YES, the next step S
6, the zoom position data Zpx obtained by the zoom position detection circuit 19 is stored, the photometry circuit 20 operates based on a command from the CPU 15, and photometry and exposure calculation are performed.

Then, the process proceeds to the next Step S7,
Data BoL (t) for checking the amount of blur
Is obtained from the check data Box and the zoom position data Zpx as BoL (t) = f (Bok, Zpx).

Then, the process shifts to the next step S8, and it is judged whether or not the above-mentioned data BoL (t) is equal to or larger than the predetermined reference data C ₁ , and in the case of NO, the next step S9. Then, the flag indicating that the focus motor 7 is rotating, that is, the _Mf flag is set to "1", and the process moves in parallel to step S17 and step S44 of the flowchart shown in FIG.

On the other hand, if YES at step S8,
Since the amount of camera shake in the camera body is so large that it cannot be corrected, it is determined that the photographer intentionally moves the camera body, for example, pans a subject that moves at high speed, and decides not to perform camera shake correction. , And shifts to step S10.

In step S10, the inhibition signal I is sent from the CPU 15 to the sampling circuit 6b of the camera shake detection unit 6 and the actuator drive circuit 14 to stop sampling and shake correction. Then, the process shifts to the next step S10 to perform photometry and distance measurement for photographing. At this time, the subject distance data Dx obtained by the AF circuit 16
Is input to the AF data conversion circuit 17 and the contents of the zoom position data Zpx obtained by the zoom position detection circuit 19 are added (details will be described later), and the focus drive data D
fx is required.

In the next step S12, the drive of the focus motor 7 is started. Then, the next step S13
Then, it is determined whether or not Dfx-Pix = 0.
This determination determines whether or not the focus drive data Dfx and the step number data (cumulative data) Pix generated in the photo interrupter 18 are equalized each time the focus motor 7 is step-driven when the focus drive is actually performed. More specifically, it is more specifically determined whether or not the focus motor 7 is step-driven by the number of steps to be focus-driven.

While step S13 is NO, step drive of the focus motor 7 is continuously performed. If YES, it is determined that focus drive has been completed, and drive of the focus motor 7 is stopped in step S14. Done.

In the next step S15, the release switch 2
It is determined whether or not 1 is turned on. If NO, the process waits as it is, and if YES, the process proceeds to the next step S16, the shutter is opened, the film exposure is started, and the delay according to the photometry result is performed. After a while, the shutter is closed. Then, after the film exposure is completed, step S4 shown in FIG.
3, the feeding motor 24 is fed through the feeding drive circuit 25.
Is driven, film winding, shutter charging, etc. are performed to prepare for the next film exposure.

If it is determined NO in step S8, that is, if the amount of camera shake is less than or equal to the predetermined value, the focus motor flag M _f is set to "1" in the next step S9. After being set, the first system including steps S17 to S43 and the second system including steps S44 to S48 shown in FIG. 5 are executed in parallel.

First, the first system will be described. The offset data is calculated in step S17 by averaging the sampling data obtained by collecting the offset data as described above to obtain the offset data Boffset average value. Ask.

Then, the process proceeds to step S18, where k = 1, V
o = 0 (Here, k is the number of times of sampling made at 32, Vo is the data for the first time in the camera moving velocity data V _k above) is set to.

Here, Vo = 0 means that the camera moving speed data V _k immediately before starting a series of camera shake detections during camera shake correction is the same as the current state when the camera is held or held. This is because it is meaningless even if this data is used as a reference because there is no guarantee that it is.

Then, in the next step S19, the data A _k (1) to A _k (32) at the 32 points are sampled, and in the next step S20, the blur change amount data B _k is calculated by the following equation. Desired.

[0091]

[Equation 3] Further, in step S20, the camera moving speed data _Vk is _{obtained as Vk} = f ( _Vk-1 , _Bk , _Bk-1 ), and this calculation is the first calculation forming the calculation means 10. Done in circuit 10a. For details, first,
This V _k based on this B _k is calculated, the current B _k is stored in the first memory 11a serving as first storage means, like this V _k is the second storage means It is stored in the second memory 11b.

Then, the current B _k stored in the first memory 11 a becomes the previous B _k−1 when the next B _k sent from the sampling circuit 6 b is accepted by the first arithmetic circuit 10 a. It is then input from the first memory 11a to the first arithmetic circuit 10a.

Also, regarding the current V _k stored in the second memory 11b, the current V _k is the first arithmetic circuit 1
Next B _k sent from the sampling circuit 6b to 0a
Is accepted, it is set to V _{k−1 of the} previous time and is input from the second memory 11b to the first arithmetic circuit 10a.
Therefore, the calculation of _Vk = f ( _Vk-1 , _Bk , _Bk-1 ) can be performed.

In the next step S21, it is determined whether the focus motor flag _Mf is "0", that is, whether the focus motor 7 is stopped. If the focus motor 7 is being driven, the process branches to NO, and the process proceeds to step S23. The value is incremented like k = k + 1, the process returns to step S19, and steps S19, S20 and S21 are executed again.

If the focus motor 7 is stopped in step S21, the process branches to YES, the process _proceeds to the next step S22, and it is determined that k = k _mfs + C ₂ (k _mfs : the value of k at the end of AF). Done.

The reason for making this determination is that the output of the camera shake detection unit 6 immediately after the focus motor 7 is driven and stopped at the time of focusing has a shock component due to motor stop. This is because accurate prediction driving cannot be performed when used for prediction calculation, and therefore C ₂ (for example, 5) more samplings than the value of k ( _kmfs ) at the end of AF are waited.

If YES in the step S22, the process proceeds to the next step S24, and the release switch 2
It is determined whether or not 1 is ON. If not, it is incremented in step S23 and steps S19 to S22 are executed again.

If YES at step S24, the process proceeds to step S25 and BLwide = f (V _k , Dx).
Is calculated, and then BLzp = f (BL
wide, Zpx) is calculated and the next step S2
At 7, BLzp is converted to BL.

Next, various operations and conversions in steps S25 to S27 will be described in detail. First,
The relationship between the blur correction data BLzp, which is the output of the calculation means 10 (the output of the third calculation circuit 10c), and the focal length of the photographing optical system, specifically the zoom position data Zpx, is the same. Even with the amount of camera shake, there is a relation that the image position movement on the film surface increases as the focal length increases.

Therefore, if the reference zoom position in the photographing optical system is on the WIDE (wide angle) side and the blur correction data at this time is the reference blur correction data BLwide,
The blur correction amount data BLzp is represented by BLzp = f (BLwide, Zpx).

When the zoom position data Zpx is not linearly related to the actual change in the focal length, an approximate calculation is used. BLzp = BLwide × f (Zpx) where f (Zpx) = a ₀ + a ₁ Zpx or f (Zp
x) = a ₀ + a ₁ Zpx + a ₂ Zpx ₂ . Here, a ₀ , a ₁ , and a ₂ are predetermined constants.

Now, the above-mentioned reference blur correction data BLw
ide and between the camera moving velocity data _{V k, BLwide = f (V} k As also shown in step S25,
Dx) holds, and the necessity of the subject distance data Dx in this case will be described with reference to FIG. 7.

In the photographing optical system R having the film surface 2 inside the rear side of the camera body P and having the principal point Q inside the front side, the camera body P moves upwardly with respect to the optical axis O by a distance y _1. imaging point against the point a ₁ When moved only, point a ₁ and the intersection a ₃ between the straight line and the film surface 2 that connects the point B ₂
become. The above-mentioned point B ₂ is a point above the intersection B ₁ of the vertical line of the principal point Q and the optical axis O by the distance y ₁ .

On the other hand, the image forming point of the point A ₁ at the initial position (position before movement) of the camera body P is the point A ₂ , and this point A ₂ is the point A _{4 on} the film surface 2 after the camera movement.
Since the camera body P has moved upward by the distance y ₁ since it corresponds to the point (moved upward by the distance y ₁ from the point A ₂ ), the point A ₄ is the point A ₄ considering the film surface 2 as a reference.
_It is the same as moving to ₃ .

Here, the camera body P moves upward by a distance y.₁Is
Consider a method to prevent the imaging position from moving even if
If you get point A₁And point A_FourIntersection between the straight line connecting the points and the principal point Q position
Point B _ThreeAdjust to move the shooting optical system to
It will be. The amount of this movement (point B_TwoAnd point B_ThreeDifference distance)
The distance y_TwoAnd the distance from the principal point Q to the film surface 2
x₁And point A₁To the principal point Q is x_TwoTosure
If y₁/ (X₁+ X_Two) = (Y₁-Y_Two) / X_TwoSuccess
Stand up, distance y_TwoIs y_Two= {X₁/ (X₁+ X_Two)} ・ Y₁ Becomes

Therefore, the distance y ₂ is affected by the distance x ₂ (subject distance).

Therefore, the object distance data Dx is necessary even when the camera moving speed data V _k is converted into the reference blur correction data BLwide, and BLwide = f (V _k , Vk, as shown in step S25 described above. D
x) is required.

If the object distance data Dx is not linearly related to the change in the distance x ₂ , BLwide = V _k , as in the case of the correction by the approximate calculation in the zoom position data Zpx described above. × f (Dx) However, f (Dx) = b ₀ + b ₁ Dx or f (Dx) = b ₀ +
The form is b ₁ Dx + b ₂ Dx ₂ . The symbols b ₀ , b ₁ and b ₂ are predetermined constants.

On the other hand, the camera moving speed data V _k has been described above as the moving speed of the image forming position on the film surface.
If this is used with the current moving speed, the response delay occurs as described above. This has already been described with reference to FIG. 18, but can be expressed by the following equation.

[0110]

[Equation 4] Alternatively, V _k = f (V _k-1 , B _k ) = (V _k-1 ) + B _k .

Now, the calculating means 10 performs the camera shake prediction correction on the basis of the current shake change amount data B _k , the previous shake change amount data B _k-1, and the previous camera moving speed data V _k-1. Specifically, in the present embodiment, when the camera shake condition is substantially sinusoidal like the characteristic a shown in FIG. 6, the camera shake correction drive that follows the motion is indicated by the symbol b. Like

That is, as shown in the enlarged view of FIG. 9, the speed at the point B1 at the current time t and the speed at the point A1 at the time t-It, which is an integration time It per time before the time t, is 1 after the time t. Time t + I, which is ahead of the integration time It per time
Predict the velocity of point C2 at t, in other words time t
The speed of the point C1 at + It is obtained by linear approximation.

Although it is desirable that the points C1 and C2 are completely coincident with each other, in reality, a slight error component occurs because the change of the characteristic a is substantially sinusoidal and the prediction is obtained by linear approximation. However, this amount is usually negligible and causes no particular problem.

Then, at the predicting time t + It,
Mera movement speed data V_kIs V_k= F (V _k-1，
B_k, B_k-1), And from another perspective V_k= V
_k-1+ 2B_k-B_k-1Can be obtained by

Therefore, when the shake correction amount data BLzp is obtained in step S26, this data BLzp is converted into the shake correction drive data BL in the next step S27.

Specifically, the actuator drive circuit 14
Done in. The shake correction drive data BL is obtained by calculating the shake change amount data B _k obtained by the hand shake detector 6 a plurality of times, and based on this, a predetermined prediction time (in the present embodiment, after the integration interval It). It is obtained by predictive calculation of the shake correction amount at the time point), and is an amount corresponding to the amount of camera shake at the prediction time point. Therefore, in order to correct the camera shake at the time of prediction, the camera shake correction amount data BLzp is converted to the camera shake correction drive data BL with the phase inverted so as to cancel the camera shake.

Therefore, in step S27, the shake correction amount data BLzp is converted into the shake correction drive data BL, the shake correction actuator 9 is driven in the next step S28, and the correction optical member 5 is orthogonal to the optical axis O. The camera shake prediction correction is performed by moving to.

Then, the shutter is opened in the next step S29, the sampling interval It is subtracted from the shutter time Ss in the next step S30, and the subtracted time Ss is 0 or less in the next step S31. Whether or not it is determined, and if NO is determined in the next step S32, the number of samplings k
Is incremented.

Then, from step S33 to step S3
8 is the above-mentioned steps S19, S20, S25, S26,
The same operation as in S27 and S28 is performed, and after the shake actuator is driven in step S38, the process returns to step S30, and in step S30, the time Ss obtained by subtracting the sampling interval It from the shutter speed is obtained and the next step S30.
At 31, it is determined whether the time Ss is 0 or less,
If NO, steps S32 to S38 are performed again as described above.

These steps S32 to S3
8 is repeated according to the determination made in step S31.
<0? Is determined to be YES, in other words, while the shutter is open, the shake prediction correction is repeatedly performed based on the shake detection.

If YES in step S31, the process proceeds to step S39, and it is determined whether or not the shutter is closed, and if NO, step S3 is performed again.
9 is executed to enter the standby state, and if YES, the process proceeds to the next step S40, and the blur correction actuator 9 is driven in the direction opposite to the blur correction direction and is driven to return to the initial position. In the next step S41, the operation of the actuator drive circuit 14 is stopped by the prohibition signal I sent from the CPU 15, and the blur correction actuator 9 is stopped.

Next, also in step S42, the sampling circuit 6b of the camera shake detection unit 6 stops its operation by the prohibition signal I sent from the CPU 15 in the same manner as in step S41 described above, and the process proceeds to the next step S43.
Film preparation such as film winding, shutter charging, etc. is performed in preparation for the next shooting, and the operation of the first system in the sequence of the camera shake prediction correction is completed.

On the other hand, the operation of the second system shifts to step S44 when the focus motor flag becomes "1" in step S8, and the photometry circuit 20 is controlled based on the instruction from the CPU 15 to perform photometry. The shutter speed and aperture value corresponding to the proper exposure value based on the measured value are obtained.

At the same time, the AF circuit 16 causes the CPU 1
The distance measurement is performed under the control of the command from 5, and the subject distance data Dx obtained at this time is converted into the focus drive data Dfx by the AF data conversion circuit 17,
In the next step S45, the focus is driven by this data Dfx.

Then, the processing shifts to step S46, where Dfx-
A determination is made as to whether Pix = 0. This determination is based on the focus drive amount data Dfx corresponding to the drive step number of the focus motor 7 when the focus drive is actually performed, and the step number data Pi generated in the photo interrupter 18 every time the focus motor 7 is step-driven.
It is determined whether or not the cumulative value of x is equal, and more specifically, it is determined whether or not the focus motor 7 is step-driven by the number of steps to be focus-driven.

Then, in the case of NO in step S46, the step drive of the focus motor 7 is continuously performed, and in the case of YES, it is determined that the focus drive is completed, and in the next step S47, the focus motor 7 is driven. The drive is stopped.

In the next step S48, the focus motor flag M _{f is set} to “0”, that is, the motor is stopped, and the value of k at the end of AF, that is, k _mfs is set to k. It is prepared for the system flow to be executed in parallel to perform blur correction, film exposure, and the like.

Therefore, in the first embodiment described so far, the camera shake detection is performed at a predetermined interval (sampling interval I).
The shake change amount data B _k obtained this time
8 and FIG. 8 because the prediction calculation is performed based on three types of data, that is, the shake variation amount data B _k−1 obtained last time and the camera movement speed data V _k−1 obtained last time. Assuming that the camera shake vibration is substantially sinusoidal like the characteristic a shown in FIG. 9, the shake drive amount at the next time point t + It is obtained by linear approximation based on the data at the current (current) time point t and the previous time point t-It. Therefore, the shake correction can be performed at a position substantially equal to the shake vibration at the next time point t + It.

Therefore, the movement of the image on the film surface is such that the blur amount characteristic e is substantially equal to the substantially sinusoidal correction amount characteristic d as shown in FIG. As shown in f, only a very small amount of undercorrection remains. Since this correction shortage amount is extremely small, it does not cause a substantial adverse effect.

In the above embodiment, three types of data are used for the prediction calculation performed to cancel camera shake, that is, the shake change amount data B _k obtained this time and the shake change amount data B obtained last time.
_k-1 and the previously obtained camera movement speed data V _k-1
Since it is performed based on the above data, it is possible to perform camera shake correction with excellent followability, and it is possible to obtain a camera that is substantially satisfactory under general conditions.

Next, another example of an apparatus for detecting destruction (abnormality) of the acceleration sensor, which is the most characteristic feature of the present invention, will be described with reference to FIG. Reference numerals 201 to 206 in FIG. 11 are the same as the configuration of FIG. 2 described in the above embodiment, and are those in which an additional circuit is added to the bridge circuit forming the acceleration sensor.

That is, the resistor 20 forming a bridge circuit
2, 204 connection point a, resistors 204 and 203 connection point c (ground end G), and resistors 202 and 205 connection point b.
And the connection point d of the resistors 205 and 203 are respectively connected to buffer amplifiers 207, 208, 209 and 210.
Are connected to the analog input terminals of the A / D converter 211 via.

Therefore, 4 input to the A / D converter 211
One analog input is converted into a digital value and output in four systems. The output ends of the four systems are connected to the input end of the determination circuit 212, and the output end of the determination circuit 212 is connected to the display 213. In addition, the determination circuit 212
Determines that the acceleration sensor is abnormal (destroyed) when any of the following four conditions is satisfied.

Va ≦ Vc, Va ≧ Vb, Vd ≦ Vc, Vd ≧ Vb where Va: voltage at the connection point of the resistors 202 and 204, Vb: voltage at the connection point of the resistors 202 and 205, Vc: resistor 204, Voltage at connection point of 203 Vd: Voltage at connection point of resistors 205 and 203.

Therefore, the resistor 2 forming the acceleration sensor
The output voltage between both ends of 02 to 205 is detected, and it is determined to be abnormal when any one of the above four conditions is satisfied.

The first condition is Va≤Vc, and the voltage Va at the connection point between the resistors 202 and 204, that is, the voltage on one side of the bridge output voltage is the voltage Vc at the connection point between the resistors 204 and 203. That is, since it cannot be normal that the voltage becomes lower than the ground voltage, it is determined to be abnormal.

The second condition is that Va ≧ Vb and the voltage V
When a, that is, the voltage on one side of the bridge output voltage becomes equal to or higher than the voltage Vb at the connection point of the resistors 202 and 205, that is, the supply voltage on the positive side to the bridge circuit, it is determined to be abnormal.

The third condition is that Vd≤Vc and the voltage V
When d, that is, the voltage on the other side of the output voltage of the bridge circuit becomes equal to or lower than the voltage Vc, that is, the ground voltage, it is determined to be abnormal.

The fourth condition is Vd ≧ Vb, and when the voltage on the other side of the output voltage of the bridge circuit becomes equal to or higher than the supply voltage on the positive side of the bridge circuit, it is judged to be abnormal.

Therefore, when the determination circuit 212 detects that at least one of the above four conditions is satisfied, the indicator 213
An output signal for generating a warning display is generated.

The abnormality detection using the acceleration sensor shown in FIG. 11 can be replaced with the circuit section including the determination circuit 27, the display 28, and the memory 29 in the above-described embodiment (see FIG. 1). Of course.

By the way, in the case where it is necessary to carry out a more advanced and superior image stabilization, for example, in the case of more severe conditions such as the use of a telephoto lens having a relatively large focal length, the following explanation will be given. It may be configured as in the second embodiment. That is, the second embodiment of the present invention is shown in FIGS.
This will be described using 5.

FIG. 12 shows the circuit structure of the second embodiment of the present invention. The parts different from the structure shown in FIG.
Only the calculation means 30 and the storage means 31 are provided, and in order to avoid redundant description, the same parts are allotted with the same reference numerals.

The basic structure of the calculating means 30 is as follows:
The third arithmetic circuits 30a, 30b, 30c are sequentially connected in series, and the storage means 31 includes first, second, and third storage circuits.
It has third memories 31a, 31b, 31c.

The above-mentioned first arithmetic circuit 30a uses V _k = f (V _k-1 , B _k , B _k-1 , B _k-2 ) where V _k : (current) camera moving speed data V _k-1 : (previous) camera movement speed data B _k : (current) blur variation data B _k-1 : (previous) blur variation data B _k-2 : (previously before) blur variation data It is what you want.

The second arithmetic circuit 30b and the third arithmetic circuit 30c respectively include the second arithmetic circuit 10b and the third arithmetic circuit 10c (FIG. 1) used in the above-described first embodiment.
See)).

On the other hand, the output end of the sampling circuit 6b, that is, the output end of the camera shake detection unit 6 is connected to the input end of the first memory 31a, and the output end of the first memory 31a is connected to the first end. 1 is connected to the input end of the arithmetic circuit 30a.

Further, the output end of the first memory 31a is
It is connected to the input end of the second memory 31b, and the output end of the second memory 31b is connected to the input end of the first arithmetic circuit 30a. The output end of the first arithmetic circuit 30a is connected to the input end of the third memory 31c, and the output end of the third memory 31c is connected to the first arithmetic circuit 30a.
Is connected to the input end of.

Next, the camera shake correction operation in the camera with the camera shake correction function according to the second embodiment configured as described above will be described.

The flowcharts shown in FIGS. 13 and 14 show the operation of the present embodiment, and since there are many parts that are the same as the flowcharts (FIGS. 3 and 5) in the above-mentioned first embodiment, duplicate explanations are avoided. The description of the case where the same operation is performed will be omitted, and only the parts that perform different operations will be described.

Step P1 in FIG. 13 and FIG.
To Step P19 and Steps P44 to P48 are Step S1 in the above-described first embodiment.
~ S19, S44 ~ S48 is the same operation. Therefore, after the process up to step P19 is executed in the same manner as in the first embodiment, the process moves to step P20.

In this step P20, the blur change amount data B _k and the camera moving speed data V _k are sampled by the sampling circuit 6.
It is obtained by the following equation by b.

[0153]

[Equation 5] In addition, the camera moving speed data V _k is the first arithmetic circuit 3
It is obtained by the following equation using 0a.

V _k = f (V _k−1 , B _k , B _k−1 , B _k−2 ) This detail is that the current V _k is calculated based on the current B _k , and this current B _k is calculated. Is stored in the first memory 31a,
Similarly, the current V _k is stored in the third memory 31c.
The current B _k stored in the first memory 31a is
When the next B _k sent from the sampling circuit 6 b is accepted by the first arithmetic circuit 30 a, the B
_k-1 and the first memory 31a to the second memory 31
At the same time as being input to b, it is input to the first arithmetic circuit 30a.

The previous shake variation amount data B _k-1 stored in the second memory 31b is the first arithmetic circuit 30.
When accepting the next B _k sent from the sampling circuit 6b to a, it is input from the second memory 31b is a B _k-2 before last to the first arithmetic circuit 30a.

Further, the current camera moving speed data V _k stored in the third memory 31c is the first arithmetic circuit 30.
When the next B _k sent from the sampling circuit 6 b is received in a, it is set to the previous V _k−1 and is input from the third memory 31 c to the first arithmetic circuit 30 a. Therefore, V _k = f (V _k-1 , B _k , B _k-1 , B _k-2 )
Can be calculated.

Then, in the next step P21, it is determined whether the focus motor flag M _f is "0", that is, whether the focus motor 7 is stopped. The operation of this step P21 and subsequent steps P33 is
This is the same as steps S21 to S33 (FIG. 5) in the first embodiment described above.

Step P34, which is executed after step P33 is executed, is performed in the same manner as step P20 described above, and from step P35 to step P38,
The process is performed in the same manner as steps P25 to P28 described above.

On the other hand, if "Ss <0?" Is YES in step S31, the process shifts to step P39, and it is determined whether or not the shutter is closed. If NO, step P39 is executed again. Is executed and put in the standby state, and YE
In the case of S, the process proceeds to the next step P40, the blur correction actuator 9 is driven in the direction opposite to the direction of the blur correction, and is driven so as to return to the initial position.
In response to the prohibition signal I sent from the CPU 15, the operation of the actuator drive circuit 14 is stopped and the blur correction actuator 9 is stopped.

Next, at step P42, C is carried out in the same manner as at step S42 shown in FIG.
The sampling circuit 6b of the camera shake detection unit 6 stops operating due to the prohibition signal I sent from the PU 15, and the process proceeds to the next step P43, and film feeding such as film winding and shutter charging is performed in preparation for the next shooting. The operation of the first system in the sequence of camera shake prediction correction is completed.

On the other hand, the operation of the second system is performed from step S9 to step S1 in the above-mentioned first embodiment shown in FIG.
Similar to the steps up to 6, steps P9 to P16 are performed.

Therefore, in the second embodiment described so far, the camera shake detection is performed at a predetermined interval (sampling interval I).
Each time t), the shake change amount data B _k obtained this time, the shake change amount data B _k-1 obtained last time, and the shake change amount data B _k-2 obtained last time and the shake change amount data B _k-2 obtained last time were obtained. Since the prediction calculation is performed based on the four types of data including the camera movement speed data V _k−1 , when the camera shake state is substantially sinusoidal like the characteristic a shown in FIG. The blur correction drive that follows is indicated by the symbol b.

Then, the speed at the point C2 at the current time point t and the time point t-, which is before the time point t by the integration time It per time.
The speed of the point B1 at It and the time point t-2 two points before It.
From the speed at the A1 point at It, the speed at the D3 point at the time point t + It, which is a time point after the time point t, is to be obtained by curve approximation.

That is, the time t-2 It and the time t-It 2
Letting Δ be the difference between the speed C1 at time t and the actual speed (speed at point C2) obtained from each data at time t, this Δ is Δ = B _k−1 −B _k .

Therefore, the point D1 obtained from the points B1 and C2
The data at the point D2, which is obtained by subtracting Δ from the data at time t2, is predicted to be the velocity at time t + It, which is a point after time t1 and It. When this is the formula _{V k = f (V k-} 1, B k, B k-1, B k-2) , and the another point of _{view, V k = V k-1} + 3B k -3B k- ₁ + B _k−2 .

That is, the camera movement speed V _k-1 for blur correction at the previous time (time t-It) and the amount of change in blur (integration) at each of the previous time (time t-It) and the last time before (time t-2It). As a result, B _k-1 and B _k-2 are temporarily stored in the first and second memories 31a and 31b,
This stored data and the shake change amount data B at this time (time t)
_{Using k} and _k , camera movement speed data V _k is calculated, and based on this data V _k , shake variation amount data B _k at time t + It is calculated, and prediction using so-called curve approximation is performed.

Therefore, in the second embodiment, it is possible to perform blur correction at a higher speed and with higher accuracy than in the above-described first embodiment. Shooting becomes possible.

In addition, steps P3 and P4 in FIG.
Is the same as the operation of the flowchart shown in FIG. 4 described in the first embodiment.

The circuit composed of the judgment circuit 32 and the display 33 shown in FIG. 12 corresponds to the circuit shown in FIG. 11 described above, and the magnitude conditions Va ≦ Vc, Va of the respective voltages of the bridge circuit are satisfied. Destruction of the acceleration sensor may be detected based on ≧ Vb, Vd ≦ Vc, Vd ≧ Vb.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the scope of the invention.

For example, as the correction optical member, not only the above-mentioned example but also a wedge-shaped prism may be arranged orthogonally to the optical axis, and when performing blur correction, it may be moved up and down.

Further, in the above-mentioned embodiment, the data in each of a plurality of times is used as the data necessary for performing the prediction calculation. At that time, as in the first embodiment, the data of the previous time and the data of this time are The number of times may be two, the number of data before two, the data of the previous time, and the data of this time may be three as in the second embodiment, or more times.
The selection of the number of times can be arbitrarily determined according to the size of the measurement interval, the size of the required camera shake correction accuracy, the manufacturing cost, and the like.

Further, the camera according to the present invention is not limited to the case where the taking lens is the zoom lens as described in the first and second embodiments, and is applicable to the bifocal type camera and the monofocal type camera. Needless to say, the correction optical member may be part or all of the focus lens group and the zoom lens group, or the focus lens group and the zoom lens group need to exist independently. There is no sex. In addition, it is up to the designer to freely adjust the amount of blur correction depending on the size of the subject distance, and similarly, it is also up to the designer to correct the amount of blur correction depending on the size of the focal length. is there.

Further, in the embodiment of FIG. 11, the determination circuit 212 determines the abnormality after the A / D conversion of the output voltage across each resistor, but the analog voltage is not converted. May be compared with a comparator to determine an abnormality.

[0175]

As is apparent from the above description, according to the present invention, a predetermined time is required for driving the correction optical member inserted in the optical path of the photographing optical system in the direction for blur correction. Prediction calculation is performed based on each camera movement speed data and blurring change amount data at a plurality of time points at intervals,
The shake correction data at the time of driving the above-mentioned correction optical member is obtained, and the shake correction is performed corresponding to this data, so regardless of the size of the shake of the camera operator,
In addition, even if the camera shake is continuously occurring, it is possible to effectively correct the camera shake, and as a result, it is possible to take a good picture without blurring. Can be provided.

Further, according to the present invention, since it is detected whether or not the acceleration sensor is broken, the reliability of the camera shake detection data can be remarkably improved, and the camera shake correction can be performed when the acceleration sensor is broken. Since the warning message not to be displayed is displayed, it is possible to prevent the inconvenience that the photographer has a feeling that the camera shake is corrected and takes a photograph with the camera shake.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration in a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing in detail a circuit of the acceleration sensor shown in FIG.

FIG. 3 is a flowchart for explaining the operation of the first embodiment.

FIG. 4 is a flow chart for explaining an operation of determining breakage of the acceleration sensor shown in the first embodiment.

FIG. 5 is a flowchart for explaining the operation of the first embodiment.

FIG. 6 is a waveform diagram for explaining a sampling operation in the first embodiment.

FIG. 7 is an optical path diagram for explaining the relationship between camera shake and a change in image formation point.

FIG. 8 is a waveform diagram showing a state of camera shake correction in the first embodiment.

9 is a partially enlarged view of FIG.

FIG. 10 is a waveform diagram showing the amount of camera shake after camera shake correction in the first embodiment.

FIG. 11 is a circuit diagram showing another example of the destruction determination circuit unit shown in FIG.

FIG. 12 is a block diagram showing a circuit configuration according to a second embodiment of the present invention.

FIG. 13 is a flowchart for explaining the operation of the second embodiment.

FIG. 14 is a flowchart for explaining the operation of the second embodiment.

FIG. 15 is a waveform diagram showing an operating state of camera shake correction in the second embodiment.

FIG. 16 is an optical path diagram conceptually showing the operation of a conventional camera with an image stabilization function.

FIG. 17 is a waveform diagram showing a correction operation of a conventional camera with a camera shake correction function.

FIG. 18 is a partially enlarged view of FIG.

FIG. 19 is a waveform diagram showing a temporal change in the amount of camera shake after camera shake correction in a conventional camera with a camera shake correction function.

FIG. 20 is a cross-sectional view showing the main parts of the acceleration sensor.

FIG. 21 is a characteristic diagram showing an example of acceleration detection that occurs during camera holding.

[Explanation of symbols]

 1 Photographic Optical System 2 Film Surface 3 Focus Lens Group 4 Zoom Lens Group 5 Correction Optical Member 6 Hand Shake Detection Section 6a Acceleration Sensor 6b Sampling Circuit 7 Focus Motor 8 Zoom Motor 9 Shake Correction Actuator 10, 30 Computational Means 10a, 30a 1st Computation circuit 10b, 30b Second computation circuit 10c, 30c Third computation circuit 11,31 Storage means 11a, 31a First memory 11b, 31b Second memory 31c Third memory 12 Focus drive circuit 13 Zoom drive Circuit 14 Actuator drive circuit 15 CPU 16 AF circuit 17 AF data conversion circuit 18 Photointerrupter 19 Zoom position detection circuit 20 Photometry circuit 21 Release switch 22 Photometry switch 23 Zoom switch 24 Feed motor 25 Feed drive circuit 6,29 Memory 27,212 Judgment circuit 28,213 Display 201 Stabilized power supply 202, 203, 204, 205 Resistor 206 Signal processing circuit 207, 208, 209, 210 Buffer amplifier 211 A / D converter O Optical axis P Camera body Q Principal point R Photographic optical system

Claims (5)

[Claims] 1. A correction optical member inserted in an optical path of a photographing optical system for correcting movement of an image position on a film surface caused by camera shake of a camera body, and the correction optical member is required. A camera shake correction actuator that moves or tilts in the direction, an acceleration sensor that detects camera shake of the camera body and converts it into an electrical signal, and an image sensor that corrects movement of the image position on the film surface due to camera shake of the camera body. A calculation means for calculating the shake correction data for correcting and predicting the movement of the image position on the film surface due to the shake of the camera body based on the current shake detection data detected by the acceleration sensor and the previous shake detection data. The camera shake detection data detected by the acceleration sensor is monitored, and if the camera shake detection data is about the same for a predetermined time, the acceleration is performed. A camera with an image stabilization function, comprising: a determination unit that determines that the sensor is abnormal, and an alarm display unit that issues an abnormality alarm for the acceleration sensor when the determination unit determines that the acceleration sensor is abnormal. Accelerometer damage detection device. 2. The determination means samples the camera shake detection data output from the acceleration sensor for a predetermined period and outputs the sampled data to a storage means, and the sampled values stored in the storage means are equal to each other for a predetermined time or longer. The damage detection device for an acceleration sensor of a camera with a camera shake correction function according to claim 1, wherein the acceleration sensor is determined to be abnormal. 3. A correction optical member inserted in the optical path of a photographing optical system for correcting movement of an image position on a film surface caused by camera shake of a camera body, and the correction optical member is required. A camera shake correction actuator that moves or tilts in the direction, an acceleration sensor that detects camera shake of the camera body and converts it into an electrical signal, and an image sensor that corrects movement of the image position on the film surface due to camera shake of the camera body. A calculation means for calculating the shake correction data for correcting and predicting the movement of the image position on the film surface due to the shake of the camera body based on the current shake detection data detected by the acceleration sensor and the previous shake detection data. , An analog voltage converter that converts the analog voltage between each resistance of the acceleration sensor configured by connecting the displacement / electricity conversion resistance to a bridge. A digital / digital converting means and a digital voltage output from the analog / digital converting means to determine whether the acceleration sensor is abnormal or not; and when the determining means determines that the acceleration sensor is abnormal. A breakage detection device for an acceleration sensor of a camera with a camera shake correction function, comprising: an alarm display means for giving an alarm of acceleration sensor abnormality. 4. Shake correction data for correcting and predicting movement of an image position on a film surface due to camera shake due to camera shake detected by an acceleration sensor and previous camera shake detection data. By calculating, and driving the shake correction actuator based on this shake correction data, the correction optical member inserted in the optical path of the photographing optical system of the camera body is moved or tilted in the required direction to cause camera shake. The movement of the image position on the film surface that occurs is corrected, the camera shake detection data of the acceleration sensor is monitored by the determination means, and if the camera shake detection data is the same for a predetermined time, it is determined that the acceleration sensor is abnormal. A method for detecting breakage of the acceleration sensor of a camera with an image stabilization function, which is characterized by displaying an alarm. 5. Shake correction data for correcting and predicting movement of an image position on a film surface due to camera shake caused by camera shake based on detection data of camera shake detected by an acceleration sensor and previous shake detection data. By calculating, and driving the shake correction actuator based on this shake correction data, the correction optical member inserted in the optical path of the photographing optical system of the camera body is moved or tilted in the required direction to cause camera shake. The resulting movement of the image position on the film surface is corrected, and each analog voltage between the resistors of the acceleration sensor configured by connecting the displacement / electricity conversion resistors in a bridge is converted into a digital voltage by the analog / digital conversion means. Then, the digital voltage is compared and judged by the judgment means based on a predetermined judgment condition and the acceleration sensor is judged to be abnormal. When there was boss, breaking detection method of the acceleration sensor of the camera shake correction function camera, characterized by alarm display by the warning display means.