JPH1010596A - Camera provided with blur correction function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera provided with blur correction function capable of making a release time lag small, shortening the driving time of an actuator for blur correction and saving power. SOLUTION: The shake of the camera is detected by an angular velocity detecting sensor 8. Concerning the detection signal, a DC component is cut by a high-pass filter 11a and integrated by a low-pass filter 11b in a microcomputer 11 so as to obtain positional information. Based on the information, a variable apex angle prism 4 is driven and a photographing optical axis is varied to correct the blur. By half pressing a release button, an autofocusing permission signal S1 is generated to execute autofocusing operation. By fully pressing the release button, a photographing permission signal S2 is generated to start the shake correction, and a shutter 2 is opened or closed to execute photographing. Before the blur correction, the operation of cutting the DC component is stopped and the offset component of the positional information is cut, so that creeping of the positional information is eliminated, a wide position correcting range is secured, and opening/closing the shutter can be performed immediately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera which detects a shake caused by a hand shake or the like and optically corrects the shake based on the shake information.

[0002]

2. Description of the Related Art In recent photographing apparatuses, for example, cameras, almost all photographing operations such as exposure determination and focusing are automated, and photographing failures due to the functions of the camera itself are extremely reduced. Recently, a camera has been developed that automatically suppresses a failure in photographing due to causes other than the camera, for example, blurring of a photographed image due to vibration such as hand shake.

A camera that corrects this camera shake detects a camera shake by an acceleration sensor or an angular velocity sensor, converts the detected shake signal into a position information by performing an arithmetic process such as integration, and converts the signal into position information. Based on this, the optical axis conversion element, for example, a variable apex angle prism is driven to correct the blur.
In order to efficiently carry out these blur corrections, it is conceivable to use an image stabilizing function in accordance with a camera sequence. Japanese Patent Application Laid-Open Nos. Sho 62-47013 and Sho 62-22
Japanese Patent Application Laid-Open No. 21112, Japanese Patent Application Laid-Open No. 1-185611, Japanese Patent Application Laid-Open No. 2-100019, Japanese Patent Application Laid-Open No. 2-157732, and Japanese Patent Application Laid-Open No. 4-20940 are examples.

[0004]

However, compact cameras such as lens shutter cameras have been downsized and the power requirements have become stricter than before. Therefore, power consumption must be reduced as much as possible. Therefore, it is necessary to shorten the time during which vibration is prevented as much as possible.

[0005] In addition, the shake angle at which vibration can be prevented is ± several degrees, and if vibration is not performed near the center, an end is hit and the vibration cannot be performed halfway. Therefore, in order to effectively use the movable range of vibration isolation, as described in the above-mentioned publication,
Processing is performed such that the image is shifted in the direction opposite to the camera shake for a predetermined time, and then the camera shake is followed.

However, when this operation is performed, a release time lag occurs in which a moment when a photograph is desired to be taken and a moment when the shutter is opened, and a driving time for extra vibration reduction is required.

Further, as described in the above-mentioned conventional example, it is mentioned that integration is permitted by a shutter release signal.

[0008] However, this operation requires time until the integration is stabilized, so that a release time lag occurs and extra drive time is required for vibration isolation.

Further, when the photographer changes the angle of view after focusing, a panning operation is performed, and the target position for image stabilization greatly changes. As a result, the target position signal is cut by a high-pass filter for DC cutting and a low-pass filter for integration for converting angular velocity into angular displacement by a calculation in the microcomputer to cut a DC component (including low frequency). Trying to return to the center to
If the image is taken at that moment, the trajectory of the signal to be returned to the center other than the camera shake signal overlaps, and the effect of vibration reduction cannot be sufficiently obtained.

The present invention has been made under such circumstances, and it is an object of the present invention to provide a camera with a blur correction function that has a small release time lag and can shorten the drive time of an anti-vibration actuator. It is.

[0011]

In order to achieve the above object, according to the present invention, a camera with a blur correction function is provided by the following (1).
To (7).

(1) Shake detection means for detecting camera shake, position information generation means for cutting and integrating the direct current component of the output of the shake detection means to generate position information, and output of the position information generation means A photographing optical axis changing means for changing a photographing optical axis of the camera, a photographing permission signal generating means for generating a photographing permission signal, and a direct current of the position information generating means according to an output of the photographing permission signal generating means. A camera with a shake correction function, comprising: a control unit for stopping a minute cut operation and cutting an offset of position information. (2) an auto-focusing means, an auto-focusing permission signal generating means for generating an auto-focusing permission signal for permitting the operation of the auto-focusing means prior to the generation of the photographing permission signal, and an output of the auto-focusing permission signal generating means. The camera with the shake correction function according to the above (1), further comprising a power-on means for turning on the power of the shake detection means in response to the power.

(3) There is provided a release switch which is pressed in two stages, wherein the shake detecting means starts operating in response to pressing of the first step of the release switch, and wherein the photographing permission signal forming means comprises: The camera with a shake correction function according to (1), wherein the camera is configured to output the photographing permission signal in response to a second pressing operation of a release switch.

(4) Shake detection means for detecting camera shake, shake correction means for correcting shake based on the output of the shake detection means, and shooting permission for generating a shooting permission signal for permitting a shooting operation. A signal generation unit for detecting an offset value of an operation position of the shake correction unit in accordance with the photographing permission signal, and cutting the offset value with respect to a control value of the shake correction unit based on an output of the shake detection unit A camera with a shake correction function, comprising: a control unit for performing correction.

(5) The camera with a shake correction function according to any one of (1) to (4), wherein the shake correction means includes a variable apex angle prism.

(6) The offset is an amount of deviation from a midpoint position of the correction range of the blur correction means (5).
Camera with blur correction function described.

(7) The blur correcting means includes a centering means for returning the blur correcting means to a middle point of the correction range, and the control means inhibits the operation of the centering means in response to the photographing permission signal. The camera with the shake correction function according to (4), wherein the control value of the shake correction means is corrected using the offset value at that time.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to embodiments of a "silver film camera" and an "electronic still camera". In each of the embodiments, as shown in FIG. 5, blur correction is performed at a position corresponding to the center value (2.5 V) of the electric signal. However, the present invention is not limited to this. It is also possible to carry out the blur correction to a position corresponding to a value deviated from the center value in consideration of the blur caused by the depression of the running and release buttons.

[0019]

【Example】

(Embodiment 1) FIG. 1 is a block diagram showing the configuration of a "silver film camera" which is Embodiment 1.

The light incident on the camera body 1 is the image pickup lens 1
a, passes through the shutter 2, passes through the lenses 1b, 1c, and 1d, the optical axis of which is bent by the variable vertex prism 4, and forms an image on the film 3.

The stepping motor 5 changes the prism angle of the variable apex angle prism 4 to bend the optical axis to correct camera shake.
A microcomputer (hereinafter referred to as a microcomputer) 11 includes a switch SW for generating an auto-focus permission signal S1.
When 1, 12a is pressed, the distance is measured by the distance measuring sensor 17,
A drive signal is output to the driver 16 to drive the focus motor 14, and the exposure time is set by the output of the photometric sensor 18. Further, an angular velocity detection sensor 8 such as a vibrating gyroscope
Is amplified by an amplifier 10 through a high-pass filter 9 and an angular velocity signal is taken into a microcomputer 11. The captured angular velocity signal passes through a high-pass filter 11a for cutting DC components in the microcomputer 11, passes through a low-pass filter 11b as an integral for converting the angular velocity signal into an angular displacement signal, and outputs the angular displacement signal (target position signal). The position of the stepping motor 5 is compared with the position of the stepping motor 5 by the comparator 11c, and a signal for driving the stepping motor 5 is output to the driver 7. Switches SW2 and 12 for generating photographing permission signal S2
When b is pressed, a signal for opening and closing the shutter 2 is output to the driver 6. When the shutter 2 is closed, a film winding motor 20 is used to wind the film.
And outputs a signal to the driver 19 in order to drive.

The switch SW1 is turned on by pressing a release button (also called a shutter button) halfway, and the switch S1 is turned on.
W2 is a switch that is turned on by fully pressing the release button.

Next, the correction optical system will be described with reference to FIG. As a driving means for rotating the variable apex angle prism (optical axis conversion element) 4 in the yaw direction (lateral direction), a stepping motor 5a which is a lead screw type actuator and as a driving means for rotating in the pitch direction (vertical direction) Similarly, a stepping motor 5b, which is a lead screw type actuator, is attached. The variable apex angle prism 4 has a stepping motor 5
reset sensors 5c for indicating the reference positions of a and 5b,
5d is attached. Stepping motor 5
Electric powers a and 5b are supplied and driven by motor driver ICs 7a and 7b.

The angular velocity detecting sensors 8a (for yaw) and 8b (for pitch) for detecting camera shake output a camera shake signal as an angular velocity signal, and the output signal cuts low frequency drift. Amplifiers 10a (for iodine) and 10b passing through high-pass filters (HPF) 9a (for iodine) and 9b (for pitch)
(For pitch), A / D converted and microcomputer 1
It is taken into 1. The angular velocity signals taken into the microcomputer 11 are integrated and calculated, and signals for driving the stepping motors 5a (for yaw) and 5b (for pitch) to predetermined positions are sent to the driver ICs 7a (for yaw) and 7b (for pitch). Output.

When the microcomputer 11 receives the auto-focus permission signal S 1, it performs photometry and distance measurement, and outputs a signal to the driver 16 to drive the focus motor 14. When the photographing permission signal S2 comes, a signal is output to the driver 6 to drive the shutter 2, and the shutter 2 is opened and closed for a predetermined time. Thereafter, a signal is output to the driver 19 to drive the feeding motor 20 to feed the film 3.

Here, the signal processing circuit of the angular velocity sensor 8 will be described with reference to FIG. First, the switch 24c is turned on to obtain an angular velocity signal so that a current flows through the sensor substrate itself.

Next, the outputs of the angular velocity sensors 8a and 8b are input to the high-pass filters 21a and 21b to cut low frequencies such as drift. Normally, high-pass filter 2
The frequency is set to be cut below the frequency determined by the time constants of the capacitors 1a and 21b, and the high-pass filters 21a and 21b immediately after the power of the sensor board is turned on.
The analog switches 24a and 24b are turned on in order to charge the capacitors of the above. 23 is a circuit for generating a central potential.

Next, the angular velocity signal from which the low frequency has been cut is taken into the microcomputer 11 via the amplifiers 22a and 22b.

Next, the operation flow of this embodiment will be described with reference to FIG. Each processing is performed by the microcomputer 11.

First, when the switch SW1 is depressed at a certain time (step 101), the microcomputer 11 turns on the power supply to supply a current to the sensor substrate (step 102).
The capacitors of the high-pass filters 21a and 21b are charged (step 103), the capacitors are charged for a predetermined time (step 104), and the charging of the capacitors is completed (step 105). Next, A / D conversion for taking in the angular velocity signal is performed (Step 106), and the signal is applied to the high-pass filter 11a (Step 107), and then applied to the low-pass filter 11b (Step 108), and is converted into a target position signal (Step 106). 109). Then, switch SW
Steps 106 to 109 until 2 is pressed
Are repeated (step 110). If the switch SW2 has not been pressed within the predetermined time, the process returns to step 101 (step 112). A when switch SW2 is pressed
/ D conversion (step 111), and step 107,
The operation of DC cut in the processing of the high-pass filter 11a and the low-pass filter 11b performed in step 108 is stopped and replaced with only the integration operation (step 113), and the target position is set based on the result of this integration (step 11).
4) The offset of the target position generated when the switch SW2 is pressed is cut (step 115), and the motors 5a and 5b for moving the variable apex angle prism 4 are driven (step 116), and the shutter is released. 2 is released (step 117). Next, when the shutter is opened for a predetermined time (step 118), the shutter is closed (step 119).

When the photographing is completed, the positions of the motors 5a and 5b are reset, and the operations of the high-pass filter 11a and the low-pass filter 11b in the microcomputer 11 are returned to the original (step 120). If the switch SW1 is not pressed for a predetermined time, (Step 121), the power of the sensor substrate is turned off.
FF is performed (step 122), and the process returns to step 101.

Since the DC cut operation is stopped only for a very short period of time, the DC cut does not cause any significant misalignment of the positional information.

Next, the operation timing of this embodiment will be described with reference to FIG.

After the switch SW1 is pressed and the capacitors of the high-pass filters 21a and 21b are charged and a large camera shake occurs due to panning or the like, as shown in FIG. After a while, it tries to return to the center due to the operation of the DC component cut by the high-pass filter 11a and the low-pass filter 11b. If the switch SW2 is pressed during this time and the shutter 2 is opened, the trajectories of returning to the center other than the camera shake signal overlap, and the image stabilizing effect cannot be sufficiently obtained. Then, when the switch SW2 is pressed, the high-pass filter 1
1a, by replacing the operation of the low-pass filter 11b with only the integration operation, the trajectory going toward the center can be eliminated as shown in FIG. 5 (b).

However, since the operation of the high-pass filter 11a and the operation of the low-pass filter 11b are switched during the course of returning to the center, an offset occurs at the target position. Therefore, the target position at the moment when the switch SW2 is pressed is stored as an offset amount, and the offset amount is always subtracted from the target position (cut for the offset) so that the target position is located near the center as shown in FIG. Can be moved.

By performing the above-mentioned operation, even if a large camera shake occurs, only the camera shake signal can be detected, and the variable apex angle prism 4 which is an optical axis variable element is controlled near the center of the optical axis. Therefore, the drivable angle of the optical axis variable element, that is, the optical axis changeable range can be widened.

As described above, in the present embodiment, in response to the generation of the photographing permission signal S2, the DC cut operation in the processing of the high-pass filter 11a and the low-pass filter 11b in the microcomputer 11 is stopped, and only the integration operation is performed. age,
And by cutting the offset of the location information,
Eliminating the creeping of the position information, widening the changeable range of the optical axis, and allowing the shutter to open and close immediately, the release time lag can be reduced, and the drive time of the stepping motor, which is an actuator for blur correction, can be shortened. it can.

(Embodiment 2) Although the case of a silver halide film camera has been described in the first embodiment, the present invention is not particularly limited to a silver halide film camera. Therefore, an example of an “electronic still camera” will be described as a second embodiment.

FIG. 6 shows the configuration of this embodiment.

The light incident on the camera body 1 is
a, passes through the shutter 2, passes through the lenses 1b, 1c, and 1d, the optical axis of which is bent by the variable apex angle prism 4, and forms an image on a solid-state imaging device (CCD) 30. The stored electric charge is sent to the image signal processing circuit 31 for image processing, and
Store in 2.

The stepping motor 5 for driving the variable apex angle prism changes the prism angle of the variable apex angle prism 4 to bend the optical axis to correct camera shake.

Next, the operation of this embodiment will be described with reference to FIG.

First, when the switch SW1 is depressed at a certain time (step 201), the microcomputer 11 turns on the power to flow a current to the sensor substrate (step 202).
The capacitors of the high-pass filters 21a and 21b are charged (step 203), the capacitors are charged for a predetermined time (step 204), and the charging of the capacitors is completed (step 205). Next, A / D conversion for taking in the angular velocity signal is performed (step 206), the high-pass filter 11a is applied (step 207), then the low-pass filter 11b is applied (step 208), and the signal is converted to a target position (step 209). ). Thereafter, steps 206 to 209 are repeated until the switch SW2 is pressed (step 210). Switch SW for predetermined time
If 2 is not pressed, the process returns to step 201 (step 212). When the switch SW2 is pressed, A / D conversion is performed (step 211), and the processing of the high-pass filter 11a and the low-pass filter 11b performed in steps 207 and 208 is replaced with only the integration operation (step 21).
3) A target position is set from the result of the integration (step 21).
4), the offset of the target position generated when the switch SW2 is pressed is cut (step 215), and the stepping motor 5 for moving the variable apex angle prism 4 is driven (step 216); Is released (step 217). Next, the solid-state imaging device CCD30
Is started (step 218), and when the shutter 2 is opened for a predetermined time (step 219), the shutter 2 is closed (step 220), and the charge accumulation of the CCD 30 is ended (step 221).

When the photographing is completed, the positions of the motors 5a and 5b are reset, the operation of the high-pass filter 11a and the operation of the low-pass filter 11b are returned to the original state (step 222), and if the switch SW1 is not pressed for a predetermined time (step 2).
23) Turn off the power to the sensor board (step 22).
4) Return to step 201.

The timing at that time is as shown in FIG.

As shown in FIG. 7, the shutter 2 can be opened at the same time when the switch SW2 is pressed.
The driving time of the variable step angle prism driving stepping motor 5 is only the time during which the shutter 2 is performing the opening and closing operation.

As described above, according to the present embodiment, the same effects as those of the first embodiment can be obtained.

[0048]

As described above, according to the present invention,
The release time lag can be reduced, and the drive time of the actuator for blur correction can be shortened, thereby saving power.

According to the third aspect of the present invention, the operations of the shake detecting means, the shake correcting means and the control means can be executed with good timing in accordance with the stroke of the release switch for performing the photographing operation. The anti-shake operation is prevented, and the time lag during shooting is reduced.

According to the fourth aspect of the present invention, it is possible to detect an offset value of the operating position of the blur correcting means at the time of photographing, and to perform a correction for cutting the offset value. Can be corrected to
The time lag before shooting can be minimized, unnecessary blur correction operation can be prevented, and power consumption can be reduced.

According to the fifth to seventh aspects of the present invention, in the optical blur correction means such as a variable apex angle prism, the influence of the movement of the image due to the centering operation can be prevented, and the photographing timing can be accurately determined. , And in particular, power consumption by the mechanical drive unit can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a first embodiment.

FIG. 2 is a detailed view of a correction optical system.

FIG. 3 is a diagram showing a signal processing circuit of the angular velocity sensor;

FIG. 4 is a flowchart showing the operation of the first embodiment.

FIG. 5 is a time chart illustrating the operation of the first embodiment.

FIG. 6 is a diagram showing a configuration of a second embodiment.

FIG. 7 is a flowchart showing the operation of the second embodiment.

[Explanation of symbols]

 Reference Signs List 4 Variable vertex prism 8 Angular velocity detection sensor 11 Microcomputer 11a High pass filter 11b Low pass filter S2 Shooting permission signal

Claims (7)

[Claims] 1. A shake detecting means for detecting camera shake, a position information generating means for cutting and integrating a direct current component of an output of the shake detecting means to generate position information, and an output of the position information generating means. A photographing optical axis changing unit for changing a photographing optical axis of the camera, a photographing permission signal generating unit for generating a photographing permission signal, and a DC component of the position information generating unit according to an output of the photographing permission signal generating unit. A camera with a shake correction function, comprising: control means for stopping a cutting operation and cutting an offset of position information. 2. An auto-focusing means, an auto-focus permission signal generating means for generating an auto-focus permission signal for permitting the operation of the auto-focus means prior to generation of a photographing permission signal, and an auto-focus permission signal generating means. 2. The camera with a shake correction function according to claim 1, further comprising: a power-on means for turning on the power of the shake detection means in accordance with the output. 3. A release switch which is pressed in two stages, wherein the shake detecting means starts operating in response to pressing of the first stage of the release switch, and wherein the photographing permission signal forming means comprises: The camera with a blur correction function according to claim 1, wherein the camera is configured to output the photographing permission signal in response to a second pressing operation of a switch. 4. A camera shake detecting means for detecting camera shake, a camera shake correcting means for correcting camera shake based on an output of the camera shake detecting means, and a camera permit signal for generating a camera permit signal for permitting a camera operation. A correction unit configured to detect an offset value of an operation position of the shake correction unit in accordance with the photographing permission signal and to cut the offset value with respect to a control value of the shake correction unit based on an output of the shake detection unit A camera with a shake correction function, comprising: 5. The camera with a blur correction function according to claim 1, wherein said blur correction means includes a variable apex angle prism. 6. The camera with a blur correction function according to claim 5, wherein the offset is a shift amount with respect to a middle point position of a correction range of the blur correction means. 7. The image stabilizing unit includes a centering unit that returns the image stabilizing unit to a middle point of the correction range, and the control unit prohibits the operation of the centering unit in response to the photographing permission signal. 5. The camera with a shake correction function according to claim 4, wherein the control value of the shake correction means is corrected using the offset value at that time.