JPH0943664A - Shake correction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To consecutively and smoothly control a shake correction device after it is restarted in the case shake correction control is required again by constituting the shake correction device so that the actions of the device may not be stopped but controlled by judging that the shake correction control is not required. SOLUTION: A shake correction control part is composed of a microcomputer for vibration-proof control 3, a microcomputer for an ultrasonic motor 16, a microcomputer for communication 24, which are in a lens device 1, and a microcomputer for a body 25 in a body device 2. When a state where the output value of a shake detection part is smaller than a previously set specified value is continued for a fixed time or more, the shake correction control part changes the decided output value of a shake correction driving part to a small value so as to keep the shake correction device finely acting. In the case the output value of the shake detection part becomes equal to or above a specified value after changing to the small value, it is immediately restored to the output value of the shake correction driving part decided based on the output value of the shake detection part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blur correction device for correcting blur of an optical axis in a photographing optical system of a photographing device.

[0002]

2. Description of the Related Art Conventionally, an AF device has been generally used in a photographing device typified by a camera, and in recent years, it has been proposed to add a shake correction device for correcting camera shake.

That is, the shake correction device is an image shake correction photographing device that detects an angular variation of the optical axis due to camera shake or the like and corrects a photographed image based on the detected amount, for example, Japanese Patent Laid-Open No. 2-66535. In Japanese Patent Laid-Open No. 2-183217, a part of the photographing optical system of the internal focusing type telephoto lens is shifted in a blur suppressing direction. Examples of performing image blur correction have been proposed.

However, in these shake correction devices, the shake correction control is continued even when the output of the shake detection unit becomes lower than a certain level, so that the power consumption becomes unnecessarily large and the battery consumption becomes low. The driving sound generated at an early stage or by driving the shake correction device sometimes gives the photographer an uncomfortable feeling.

Therefore, in Japanese Patent Laid-Open No. 4-56831, the necessity of the shake correction control is judged from the magnitude judgment of the signal input from the shake detection unit with respect to a predetermined value, and when it is not necessary, the shake correction device is forced. It has been proposed to reduce the power consumption and suppress the driving sound by stopping the motor.

[0006]

However, Japanese Unexamined Patent Publication (Kokai) No. 4-5.
In the invention proposed by Japanese Patent No. 6831, it is certainly possible to reduce both power consumption and drive noise. However, for example, it is determined that shake correction control is not necessary, and the shake correction device is forced to operate. If the shake correction control becomes necessary again after the automatic stop, it becomes difficult to control the shake correction device after the restart continuously and smoothly.

Therefore, after the restart of the shake correction device until a certain time has elapsed, it is impossible to perform the shake correction with high accuracy, and there is a problem that the characteristics of the shake correction device cannot be fully exhibited. It was

[0008]

According to the present invention, when it is determined that the shake correction control is not necessary, the shake correction device is not stopped in order to smoothly perform the operation at the time of restarting after restoration. , For example, by reducing the output value from the shake correction control unit and continuing to operate the shake correction device minutely,
This is to solve the above problem.

That is, according to the first aspect of the present invention, the blur detection unit for detecting the blurring of the optical axis of the photographing optical system of the photographing device, a part or all of the photographing optical system, and the photographing screen of the photographing device are relative to each other. In a shake correction device including a shake correction drive unit that is moved dynamically, and a shake correction control unit that determines the shake correction drive unit output value based on the shake detection unit output value, the shake correction control unit includes When the state where the detection unit output value is smaller than the predetermined value continues for a certain period of time or longer, the determined shake correction driving unit output value is changed to a small value to obtain a new shake correction driving unit output value. It is characterized by

According to a second aspect of the present invention, in the blur correction device according to the first aspect, after the blur correction control section changes the output value of the blur correction drive section to a smaller value,
When the output value of the shake detection unit is equal to or more than the predetermined value, the output value of the shake correction drive unit determined based on the output value of the shake detection unit is restored.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) An embodiment of the present invention will be described below in more detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a blur correction device according to the present invention, and FIG. 3 is a schematic diagram showing a configuration including a photographing optical system of the blur correction device according to the present embodiment.

As shown in FIG. 3, the blur correction device of the present embodiment is incorporated in a photographing device composed of a lens device 1 and a body device 2. The computer 3, the ultrasonic motor microcomputer 16, the communication microcomputer 24, and the like are provided, while the body device 2 is provided with the body microcomputer 25 and the like. In this embodiment, the blur correction control unit is configured by these computers.

The image stabilization control microcomputer 3 is based on the output of the body microcomputer 25 of the body device 2 and the optical system position information from the X encoder 5, Y encoder 9, distance encoder 15, zoom encoder 22 and the like. Then, it controls the drive of the shake correction drive unit composed of the X-axis drive motor 7, the X-axis motor driver 8, the Y-axis drive motor 11, the Y-axis motor driver 12, and the like.

The lens contact 4 is a group of electrical contacts used for exchanging signals with the body device 2, and is connected to the communication microcomputer 24. The X encoder 5 is for detecting the amount of movement of the optical system in the X-axis direction, and its output is connected to the X encoder IC 6. X encoder I
C6 is for converting an optical system movement amount in the X-axis direction into an electric signal, and the signal is sent to the image stabilization control microcomputer 3. The X-axis control motor 7 is a drive motor that drives the X-axis image stabilization optical system. The X-axis motor driver 8 is a circuit that drives the X-axis drive motor 7.

Similarly, the Y encoder 9 is for detecting the amount of movement of the optical system in the Y-axis direction, and its output is connected to the Y encoder IC 10. Y encoder I
C10 is for converting the amount of movement of the optical system in the Y-axis direction into an electric signal, and the signal is sent to the image stabilization control microcomputer 3. The Y-axis control motor 11 is a drive motor that drives and drives the Y-axis shake correction optical system. The Y-axis motor driver 12 is a circuit that drives the Y-axis drive motor 11.

The image stabilization head amplifier 13 is a circuit for detecting the amount of shake, converts the image shake information into an electric signal, and the signal is sent to the image stabilization control microcomputer 3. As the image stabilization head amplifier 13, for example, an angle sensor or the like can be used.

In this embodiment, the X encoder 5, the X encoder IC 6, the Y encoder 9, and the Y encoder IC 10
Further, the shake detection head amplifier 13 and the like constitute a shake detection unit.

The VR switch 14 is a switch for turning on / off the shake correction drive and switching between the shake correction mode 1 and the shake correction mode 2. Here, for example, the blur correction mode 1 is a mode in which rough control is performed when the blur of the finder image is corrected after the shooting preparation start operation, and the blur correction mode 2 is the precision when the blur is corrected during actual exposure. This is a mode for performing various controls.

The distance encoder 15 is an encoder for detecting the focus position and converting it into an electric signal, and the output thereof is similarly the microcomputer for vibration control 3, the microcomputer 16 for ultrasonic motor, and for communication. It is connected to the microcomputer 24.

The ultrasonic microcomputer 16 is for controlling an ultrasonic motor 19 for driving the focusing optical system driving section. The USM encoder 17 is an encoder that detects the amount of movement of the ultrasonic motor 19, and its output is connected to the USM encoder IC 18. US
The M encoder IC 18 is a circuit that converts the amount of movement of the ultrasonic motor 19 into an electric signal, and the signal is sent to the ultrasonic motor microcomputer 16.

The ultrasonic motor 19 is a motor for driving the focusing optical system. The ultrasonic motor drive circuit 20 is a circuit for generating two drive signals having a drive frequency specific to the ultrasonic motor 19 and having a 90 ° phase difference with each other. The ultrasonic motor IC 21 is a circuit that interfaces between the ultrasonic motor microcomputer 16 and the ultrasonic motor drive circuit 20.

The zoom encoder 22 is an encoder for detecting the lens focal length position and converting it into an electric signal, and its output is sent to the image stabilization control microcomputer 3, the ultrasonic motor microcomputer 16 and the communication microcomputer 24. It is connected.

The DC-DC converter 23 is a circuit that supplies a stable DC voltage against fluctuations in battery voltage.
It is controlled by a signal from the communication microcomputer 24.

The communication microcomputer 24 communicates between the lens apparatus 1 and the body apparatus 2 and transmits a command to the other microcomputer 3 in the lens apparatus 1, the ultrasonic motor microcomputer 16 and the like. belongs to.

The body microcomputer 25 instructs the shake correction display section 27 to display a warning based on the maximum image stabilization time information, the exposure setting information, and the subject brightness information transmitted from the lens apparatus 1.

The release switch 28 is provided in the body device 2. The release switch 28 is a half-depress switch SW1 for starting the photographing preparation operation by half-depressing the release button and the start of the exposure control by fully-depressing the release button. It is composed of a full-press switch SW2.

FIG. 2 is a flow chart for explaining the operation sequence of the image pickup apparatus according to this embodiment. Step (hereinafter "S"
Abbreviated. At 200, the communication microcomputer 24 prepares for communication. At the same time, the image stabilization control microcomputer 3 prepares for communication in S201, and the ultrasonic motor microcomputer 16 prepares for communication in S202.

In step S203, the communication microcomputer 24 communicates with the body device 2 via the lens contact 4. In step S204, the focusing control instruction received from the body device 2 is transmitted to the ultrasonic motor microcomputer 16.

In step S205, the ultrasonic motor microcomputer 16 performs focusing control based on the information from the zoom encoder 22 and the distance encoder 15. In S206, the image stabilization control instruction received from the body device 2 is transmitted to the image stabilization control microcomputer 3.

In S207, the image stabilization control microcomputer 3 performs image stabilization calculation. In S208, the image stabilization control microcomputer 3 performs image stabilization control. FIG. 4 is a diagram illustrating in detail the operation sequence of the image stabilization calculation routine S207 of FIG.

In S400, the image stabilization control microcomputer 3 of FIG. 1 reads the output voltage value of the head amplifier 13 of FIG. 1 which is the output of the shake detection unit. In S401, it is determined whether the output voltage value read in S400 is smaller than a preset upper limit value H _Limit . When the output voltage value is smaller than the upper limit value H _Limit S4
Go to 02. If the output voltage value is greater than or equal to the upper limit value H _{Limit, the} process proceeds to S403. The upper limit value H
_Limit can be set empirically as appropriate.

In S402, it is determined whether the output voltage value read in S400 is larger than a preset lower limit value L _Limit . Output voltage value is lower limit value L
_{When it is} larger than the _{Limit, the} process proceeds to S405. When the output voltage value is smaller than or equal to the lower limit value L _{Limit, the} process proceeds to S403. Note that the lower limit value L _Limit may be appropriately set empirically, like the upper limit value H _Limit .

In S403, it is determined that the angular velocity is out of the range, and the angular velocity range value inside flag L _{flag is set} to 0. S404
, The constant K _norm preset for the control coefficient G
Is stored as a control coefficient. In S411, which will be described later, a detailed calculation of the control duty is performed using the constant K _norm stored in S404.

In S405, it is determined whether or not the angular velocity range value inside flag L _flag is 0. Angular velocity range flag L
_{When flag} is 0, the process proceeds to S406. When the flag L _flag within the angular velocity range value is not 0, the process proceeds to S408.

In S406, the current time is stored in the arrival time L _time within the angular velocity range. In S407, the flag L _flag within the angular velocity range value is set to 1. At S408, the elapsed time G from the arrival time within the angular velocity range to the present time G
_Time is calculated by (current time-arrival time within angular velocity range _Ltime ).

In step S409, it is determined whether the elapsed time G _time is longer than the preset waiting time within the angular velocity range. When the elapsed time G _time is larger than the waiting time within the angular velocity range, the process proceeds to S410. When the elapsed time G _time is less than or equal to the waiting time within the angular velocity range, the process proceeds to S404. The waiting time within the angular velocity range may be determined empirically or experimentally.

In step S411, a detailed calculation of the control duty is performed using the constant K _small stored in step S410. FIG. 5 is a graph showing an example of the relationship between the output of the image stabilization head amplifier 13 which is the output of the shake detection unit indicated by the thin line and the actual control angular velocity of the shake correction optical system indicated by the thick line.

In FIG. 5, the state in which the output of the image stabilizing head amplifier 13 falls within the range from the upper limit value H _Limit to the lower limit value L _Limit does not continue for a certain time T _wait until the point A is reached. _Therefore , the shake correction optical system is controlled by the control duty calculated by the control coefficient G = constant K _norm .

During a certain time T _wait from point A, the output of the image stabilizing head amplifier 13 changes from the upper limit value H _Limit to the lower limit value L.
Due to the fact that the inside state continued for the width of _Limit ,
When the point B is reached, the control coefficient G is changed from the constant K _norm to the constant K _small .

From point B to point C, the output of the image stabilization head amplifier is smaller than the lower limit value L _Limit (upper limit value H
_The blur correction optical system is controlled by the control duty calculated by the control coefficient G by the constant K _small until the value becomes outside the range of the lower limit value L _Limit from the _Limit ).

The constant K _small is a value set so that the control angular velocity of the shake correction optical system becomes smaller than the constant K _norm . As described above, in the present embodiment, the shake correction control unit keeps the output value of the shake detection unit smaller than the predetermined value (upper limit value H _Limit , lower limit value L _Limit ) for a certain period of time T _wait or more. Then, the determined output value of the shake correction drive unit is changed to a small value, and the shake correction device continues to operate minutely.

Next, at point C, the image stabilization head amplifier 1
As soon as the output of 3 becomes smaller than the lower limit value L _Limit , the control coefficient is returned to the control coefficient G = constant K _norm which is the value used for the calculation before the point B, and the control coefficient G = constant K
_The blur correction optical system is controlled by the control duty calculated by _norm . As described above, in the present embodiment, the shake correction driving unit output value is changed to a small value (the control coefficient G is set to the constant K).
_{If the} output value of the shake detection unit becomes equal to or larger than the predetermined value after the change from _{norm to} constant K _small ), the shake correction drive is immediately determined based on the output value of the shake detection unit. Return to the partial output value.

FIG. 6 shows a conventional invention (for example, an invention proposed by Japanese Patent Laid-Open No. 4-56831) in which the drive of the shake correction drive unit is stopped when the output of the shake detection unit is below a certain level. 6 is a graph showing an example of the relationship between the output of the image stabilization head amplifier that is the output of the shake detection unit indicated by the thin line and the actual control angular velocity of the shake correction optical system indicated by the thick line.

In the control of FIG. 6, when the output of the image stabilizing head amplifier is within the range from the upper limit value H _Limit to the lower limit value L _Limit , the control of the shake correction optical system is stopped, Immediately after the output of the image stabilization head amplifier exceeds the range from the upper limit value H _Limit to the lower limit value L _Limit , the control fluctuates up and down and becomes discontinuous as shown in the figure, and smooth control cannot be achieved.

On the other hand, in FIG. 7, when the output of the shake detection unit similar to that of FIG. 6 occurs, the image stabilization head amplifier which is the output of the shake detection unit indicated by the thin line in the control according to the present invention. 13 is a graph showing an example of the relationship between the output of No. 13 and the actual control angular velocity of the shake correction optical system shown by the thick line.

In the control of FIG. 7, when the output of the image stabilizing head amplifier enters the range from the upper limit value H _Limit to the lower limit value L _Limit , the control of the shake correction optical system is continued, Even when the output of the shaking head amplifier 13 exceeds the range from the upper limit value H _Limit to the lower limit value L _Limit , the control immediately after that is continuous as shown in the figure, and the control is smoothly performed. You can continue.

Further, since the control coefficient is changed to reduce the movement amount of the shake correction device, the control angular velocity of the shake correction control system is suppressed to be small, the consumption current is prevented from being increased more than necessary, the battery consumption is delayed, and The driving sound due to the correction driving does not give the photographer an uncomfortable feeling.

(Modifications) The present invention is not limited to the above-described embodiments, but various modifications and changes are possible, and these are also included in the scope of the present invention.

For example, the lens device of the single-lens reflex camera in which the lens device and the body device are detachable has been described as an example.
It can also be applied to the lens part of a compact camera.

[0051]

As described in detail above, according to the present invention, it is determined that the shake correction control is not necessary and the operation of the shake correction device is suppressed instead of being stopped. Therefore, the shake correction control is required again. In this case, the image stabilization device after restarting can be controlled continuously and smoothly. Therefore, it is possible to reduce the battery consumption as much as possible and maintain the accuracy of the shake correction device for a longer time than before.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a blur correction device according to the present invention.

FIG. 2 is a flowchart illustrating an operation sequence of the image capturing apparatus according to the first embodiment.

FIG. 3 is a schematic diagram showing a configuration including a photographing optical system of the blur correction device according to the first embodiment.

FIG. 4 is a diagram illustrating in detail the operation sequence of the image stabilization calculation routine S207 of FIG.

FIG. 5 is a graph showing an example of the relationship between the output of the image stabilization head amplifier that is the output of the shake detection unit indicated by the thin line and the actual control angular velocity of the shake correction optical system indicated by the thick line.

FIG. 6 shows an output of the image stabilization head amplifier which is an output of the shake detection unit indicated by a thin line and a thick line in the conventional invention in which the drive of the shake correction drive unit is stopped when the output of the shake detection unit is below a certain level. 7 is a graph showing an example of the relationship with the actual control angular velocity of the shake correction optical system shown in FIG.

FIG. 7 shows the output of the image stabilization head amplifier, which is the output of the shake detection unit indicated by the thin line, and the actual shake correction, which is indicated by the thick line, in the control according to the present invention when the output of the shake detection unit is below a certain level. It is a graph which shows an example with respect to the control angular velocity of an optical system.

[Explanation of symbols]

 1 Lens Device 2 Body Device 3 Anti-Vibration Control Microcomputer 4 Lens Contact 5 X Encoder 6 X Encoder IC 7 X Axis Drive Motor 8 X Axis Motor Driver 9 Y Encoder 10 Y Encoder IC 11 Y Axis Drive Motor 12 Y Motor Driver 13 Anti-vibration head amplifier (angular velocity sensor) 14 VR switch 15 Distance encoder 16 Microcomputer for ultrasonic motor 17 USM encoder 18 USM encoder IC 19 Ultrasonic motor 20 Ultrasonic motor drive circuit 21 Ultrasonic motor IC 22 Zoom encoder 23 DC- DC converter 24 Microcomputer for communication 25 Microcomputer for body 26 Object finder 27 Blurring correction display section 28 Release switch

Claims (2)

[Claims] 1. A blur detection unit for detecting blurring of an optical axis in a photographing optical system of a photographing apparatus, and a blur correction drive for relatively moving a part or all of the photographing optical system and a photographing screen of the photographing apparatus. And a shake correction control unit that determines the shake correction drive unit output value based on the shake detection unit output value, the shake correction control unit sets the shake detection unit output value to a predetermined value. When the state of being smaller than the predetermined value continues for a certain period of time or more, the determined blur correction driving unit output value is changed to a small value to obtain a new blur correction driving unit output value. apparatus. 2. The blur correction device according to claim 1, wherein the blur correction control unit changes the blur correction drive unit output value to a smaller value, and then the blur detection unit output value is set to The blur correction device is characterized in that when it exceeds a predetermined value, it returns to the blur correction drive unit output value determined based on the blur detection unit output value.