JPH0723277A - Deflection correcting device - Google Patents

Abstract

PURPOSE:To always obtain a high grade image output by providing a second control means controlling the characteristic of a first control means based on the output of a photographing state decision means and a holding means holding a correction means in its stable state for a prescribed period. CONSTITUTION:A phase and gain correction circuit 11 corrects the output of the integration signal outputted from an integrator 5 or the phase and gain of an angle displacement signal. A photographing state decision circuit 12 performs the amplitude decision of a pan tilt, etc., and the decision of the photographing state from an angle speed signal and the angle displacement signal and controls the characteristics of an HPF 10 and the phase and gain correction circuit 11 according to the photographing state. A holding means 13 holds a correction means in its stable state so that the means may not correspond to the disordered output of a sensor at the time of turning on a power source by interrupting the output from the sensor till the output of the sensor is stabilized when the power' source is turned on or when a deflection correction operation is started. Thus, the image deflection due to the instability of the output of a deflection detection at the time of turning ON the power source or starting a vibration proof operation can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shake correcting apparatus suitable for use in a shake correcting apparatus such as a camera.

[0002]

2. Description of the Related Art Conventionally, in the field of a shake correction device for a camera or the like, automation and multifunctionality have been achieved in all aspects such as exposure setting and focus adjustment, so that good photographing can be easily performed.

However, it is often camera shake that actually deteriorates the quality of a photographed image, and in recent years, various shake correction devices for correcting this camera shake have been proposed and are attracting attention.

FIG. 14 shows an example of the configuration of a conventional shake correction device.

In FIG. 1, reference numeral 1 denotes an angular velocity detector including an angular velocity sensor such as a vibration gyro, which is attached to a shake correction device such as a camera. Reference numeral 2 is a DC cut filter that blocks the DC component of the velocity signal output from the angular velocity detector 1 and passes only the AC component, that is, the vibration component. This DC cut filter is a high-pass filter (hereinafter referred to as HPF) that cuts off a signal in an arbitrary band.
May be used. An amplifier 3 amplifies the angular velocity signal output from the DC cut filter to an appropriate sensitivity.

Reference numeral 4 is an A / D converter for converting the angular velocity signal output from the amplifier 3 into a digital signal, and 5 is an integrator for integrating the output of the A / D converter 4 and outputting an angular displacement signal, 6
Is a pan / tilt determination circuit that determines the panning / tilting from the integrated signal of the angular velocity signals output from the integrator circuit 5, that is, the angular displacement signal, and 7 is the output of the pan / tilt determination circuit that is an analog signal or a pulse such as PWM. It is a D / A converter that converts to an output and outputs. And A / D
Converter 4, integrator 5, pan / tilt determination circuit 6, D / A
The converter 7 is composed of, for example, a microcomputer (hereinafter referred to as a microcomputer) COM1. Reference numeral 8 is a drive circuit for driving the image correcting means in the subsequent stage so as to suppress the shake based on the displacement signal output from the microcomputer, and 9 is an image correcting means, for example, displacing the optical optical axis to cancel the shake. An optical correction unit or an electronic correction unit that electronically shifts an image reading position from a memory storing an image to offset the shake is used.

[0007]

However, the above shake correction apparatus has the following problems.

Immediately after the power is turned on, it often takes time for the output of the detecting means to stabilize, and there is the problem that the screen shakes and it is very difficult to see, which is extremely undesirable as a shake correction device.

[0009]

In order to solve the above problems, according to the shake correcting apparatus of the present invention, a detecting means for detecting the vibration of the apparatus and a correcting means for correcting the movement of the image due to the vibration. First control means for controlling the correction means based on the output of the detection means to operate the correction means in a direction for correcting the movement of the image;
Image pickup state determining means for determining the image pickup state from the output of the detecting means, second control means for controlling the characteristics of the first control means based on the output of the image pickup state determining means, and at power-up or Holding means for holding the correction means in a stable state for a predetermined period until the output of the detection means stabilizes at the start of the image stabilization operation.

[0010]

As a result, it is possible to prevent image shake due to instability of the shake detection output when the power is turned on or when the image stabilization operation is started.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing the main configuration of the first embodiment of the shake correcting apparatus according to the present invention. In the figure, the same components as those of the preceding example shown in FIG. 14 described above are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, an angular velocity detecting means 1 including an angular velocity sensor such as a vibration gyro attached to a shake compensating device such as a camera, a DC cut filter for cutting off a DC component of a velocity signal output from the angular velocity detecting means 1 ( Alternatively, the HPF), the amplifier 3 for amplifying the angular velocity signal to a predetermined sensitivity, the drive circuit 8, and the image correction means 9 may have the same configurations as those of the above-described prior art example shown in FIG. The difference is in the internal configuration of the microcomputer COM2 that controls the entire apparatus. In this embodiment, for example, a variable prism (VAP) or a memory control method described later is used as the image correction means 9.

Looking at the configuration inside the microcomputer COM2, A /
The D converter 4 converts the angular velocity signal output from the amplifier 3 into a digital signal, the HPF 10 has a function capable of varying in an arbitrary band, and the integrator 5 converts the signal of the predetermined frequency component extracted by the HPF 10 into a digital signal. The phase and gain correction circuit 11 corrects the integrated signal output output from the integrator 5, that is, the phase and gain of the angular displacement signal by integrating to obtain the angular displacement signal in the frequency component. And, the characteristics of the HPF 10 and the phase and gain correction circuit 11 are controlled according to the photographing state by determining the amplitude such as pan / tilt and the photographing state from the angular displacement signal, and the holding means 13 is shaken when the power is turned on or shakes. When the correction operation is started, the output from the sensor is cut off until the sensor output becomes stable, so that the correction means has a disturbed sensor It is intended to hold in a stable state so as not to correspond to the over output. The D / A converter 7 also converts the output signal of the phase and gain correction circuit 11 into a form that can be supplied to the drive circuit 8 that actually drives the image correction means 9, for example, an analog signal or a pulse output such as PWM. Output.

The specific operation of the panning / tilting judgment in the photographing state judging means 12 is to input the presence / absence of vibration of the angular velocity signal output from the A / D converter 4 and the angular displacement signal output from the integrating circuit 5, When the angular velocity is constant and the angular displacement signal obtained by integrating the angular velocity signal shows a monotonic increase, it is determined that the panning or tilting is performed.
In such a case, the low-frequency cutoff frequency of the HPF 10 is changed to a higher frequency, and the characteristic is changed so that the shake correction system does not respond to the low-frequency.

When panning / tilting is detected, the VAP is gradually centered on the center of the moving range. During this time, the angular velocity signal and the angular displacement signal are detected, and when the panning / tilting is completed, the cutoff frequency in the low frequency range is lowered again to expand the shake correction range.

Here, the drive circuit 8 and the image correction means 9 for actually correcting the shake of the image in accordance with the control signal output from the microcomputer COM2 will be described with reference to examples.
For example, the ones shown in FIGS.

FIG. 3 shows a variable apex angle prism (hereinafter referred to as VAP:
Varriable angle prisum) 306 and a voice coil as a drive system, and a closed loop control system that controls the drive amount by encoder-detecting angular displacement and feedback to the drive system. Is.

First, the VAP will be described in detail. As shown in FIG. 7, the variable apex angle prism 306 has a transparent high refractive index (refractive index n) between two transparent parallel plates 340a and 340b facing each other. A transparent parallel plate 340 is filled with an elastic body or an inert liquid 342 in a sandwiched manner, and the outer periphery thereof is elastically sealed with a sealing material 341 such as a resin film.
a and 340b are swingable, and the optical axes are displaced by swinging the transparent parallel plates 340a and 340b to correct shake.

FIG. 8 shows the variable vertical angle prism 30 shown in FIG.
6 one of the transparent parallel plates 340a is attached to the swing shaft 301 (31
Incident light flux 34 when rotated by angle σ around 1)
4 is a diagram showing a passing state of the light beam of FIG. 4, and the light beam 344 incident along the optical axis 343 is deflected by an angle φ = (n−1) σ according to the same principle as the wedge prism, as shown in FIG. Emit. That is, the optical axis 343 is decentered (deflected) by the angle φ.

Returning to the description of FIG. 3, the VAP described above is explained.
306 is fixed to the lens barrel 302 via a holding frame 307 so as to be rotatable around 301 and 311.

Reference numeral 313 is a yoke, 315 is a magnet, 3
Reference numeral 12 denotes a coil, which constitutes a voice coil type actuator capable of varying the apex angle of VAP around 311 by passing a current through the coil 312. 31
Reference numeral 0 is a slit for detecting the displacement of the VAP, which is a rotary shaft 31.
The position is displaced by rotating together with the holding frame 307, that is, the VAP 306 coaxially with 1. 308 is a slit 310
Is a light emitting diode that detects the position of the
sition Sensing Detector) and light emitting diode 3
By detecting the displacement of the slit 310 together with 08, an encoder for detecting the angular displacement of the VAP apex angle is configured.

Then, the luminous flux whose incident angle is changed by the VAP 306 is CC by the photographing lens unit 303.
An image is formed on the image pickup surface of the image pickup element 304 such as D.

Reference numeral 305 designates the center of the other rotation axis orthogonal to the rotation axis composed of the axes 301 and 311 of the holding frame 307.

Next, the basic structure and operation of the control circuit for driving and controlling the VAP will be described with reference to the block diagram of FIG.

In the figure, 306 is a VAP, 322 is an amplifier, 323 is a driver for driving an actuator, 324 is a voice coil type actuator for driving the VAP 306 described above, 326 is an encoder for detecting the vertical angle displacement of VAP, 325. Is a micro computer CO
A shake correction control signal 320 output from M2 and an output signal of the angular displacement encoder 326 are added with opposite polarities, and the shake correction control signal 320 output from the micro computer COM2 and the angular displacement encoder. Three
Since the control system operates so as to be equal to the output signal of the V.26, the VAP 306 is driven so that the control signal 320 is equal to the output of the encoder 326 as a result, and the VAP is moved to the position designated by the microcomputer COM2. Is controlled.

FIG. 5 shows another example of the image correction means, which is constructed such that the VAP described above is driven not by a voice coil type actuator but by a stepping motor.

This is done with the rotary shaft 301 as the center of rotation.
The stepping motor 401 drives the VAP via the holding frame 307. That is, a stepping motor 401 having a lead screw 401a arranged on its rotation axis is attached to a support frame 403 attached to the lens barrel 302, and the guide frame 405 of the support frame 403 allows the stepping motor 401 to move in the optical axis direction. The guided motor 404 is constantly meshed with the lead screw 401a, and the carrier 404 is rotatably connected to the connecting rod 407 fixed to the support frame 307 by the rotating shaft 406. Is rotated to move the carrier 404 in the optical axis direction, and the holding frame is rotated about the rotating shafts 301 and 311 via the connecting rod 407.
It drives P. Reference numeral 402 is a reset sensor for detecting the VAP reference position. A VAP drive mechanism similar to this is also provided for the shaft 305, but description thereof will be omitted.

The circuit configuration for driving and controlling the system of FIG. 5 is as shown in the block diagram of FIG.

In FIG. 6, the micro computer CO
The drive arithmetic circuit 4 outputs the control signal 320 output from M2.
Drive calculation is performed in 10 to convert into a drive signal of VAP,
It outputs to the driver / IC411. Then, the stepping motor 401 is driven by the driver IC to change the apex angle of VAP.

FIG. 9 shows a third example of the image blur correction means, which stores image information in a memory and sets the cut-out range of the image from the memory to be smaller than the stored image. It is configured to correct the shake by shifting the position where the image is cut out from the memory in a direction that cancels the movement of the image, and further expands the cut out image signal to correct the screen size before outputting. 2 illustrates a memory control type image shake correction means.
This system is characterized in that shake correction can be performed electronically without using an optical correction mechanism such as VAP.

In the figure, 100 is a zoom lens, and 1
01 is an image pickup device (CCD image sensor or the like) for converting an optical image into an electric signal, 102 is an A / D converter, and 103 is
Control signal (runout signal) input from the microcomputer COM2
Based on 110, a shake correction process for correcting the shake of the image by shifting the cut-out position of the predetermined image information from the field memory 106 so as to reduce the shake component in the image pickup signal, and enlarging the read image from the field memory 106. This is an image processing circuit that constitutes a view angle correction processing unit that performs processing to perform so-called electronic zooming and converts it into a normal screen size, and is realized by a microcomputer.

Reference numeral 104 is an interpolation process for interpolating one pixel signal from image information of two or more adjacent pixels by zoom information when performing electronic zoom for correcting an image read from the field memory to a normal angle of view. It is a means.
For this interpolation method, well-known means may be used,
For example, the average value between adjacent pixels may be used to interpolate between pixels. Further, 105 is a D / A converter, and 107 is an encoder for detecting the zoom magnification ratio of the zoom lens 100.

Next, the operation will be described. Zoom lens 10
The optical image that has passed 0 is converted into an electrical signal by the image sensor 101 and output as an image signal. The image pickup signal is converted into a digital signal by the A / D converter 102, and the image information for one field is written in the memory 106 via the memory control unit 103. Here, the cut-out position of the image signal from the field memory 106, that is, the read range and its read position are determined by the shake signal input from the microcomputer COM2 and the zoom information from the encoder 107.

Next, in order to convert the signal read from the field memory 106 into the original size of the scanning width of the output image, that is, the angle of view, according to the cut-out size, the number of pixels in the normal one-pixel output period is increased. Whether or not to output is determined, and the interpolation processing circuit 104 performs the interpolation processing on the pixel having no pixel information. Then, this signal is converted into an analog signal by the D / A converter 105 and output.

The specific examples of the image correction means for correcting the shake have been described above.

Next, the processing operation of the microcomputer COM2 in this embodiment shown in FIG. 1 will be described with reference to the flow chart of FIG. In the figure, when control is started, in step S1, the angular velocity signal from the angular velocity detecting means 1 from which the direct current component is removed via the DC cut filter 2 and the amplifier 3 and which is amplified to a predetermined level,
It is converted into a digital signal by the A / D converter 4 and taken into the microcomputer COM2.

Subsequently, in step S2, the angular velocity signal and the predetermined high frequency component extracted from the angular velocity signal by the HPF 10 are integrated by the integration circuit 5, and the panning / tilting and photographing states are performed by the angular displacement signal. Make a decision.

In step S3, the coefficient for setting the characteristics of the HPF 10 is read from a table (not shown) prepared in advance in the microcomputer COM2 according to the result of the determination. That is, if the HPF 10 is configured by a digital filter, the characteristics of the HPF 10 can be freely changed by reading and setting a predetermined coefficient from a table storing the coefficient.
The coefficients according to these panning / tilting and shooting conditions are empirically determined.

In step S4, the HPF 10 is calculated by the coefficient for setting the characteristic and the characteristic is set, and in step S5, the signal output from the HPF 10 is integrated by the integrating circuit 5, and the angular displacement signal ( Shake signal).

In step S6, the correction coefficient of the phase and gain correction circuit 11 is read from a table (not shown) prepared in advance in the microcomputer COM2.

The phase and gain correction circuit 11 is for compensating the deterioration of the shake correction characteristic due to the phase delay of the shake correction system, has a phase lead element, and is composed of, for example, a digital filter as described later. The correction coefficient is read out from the digital filter, and the phase and gain correction characteristics corresponding to the shake frequency are set.

In step S7, the correction calculation is performed using the coefficient obtained in step S6, and the calculation result obtained in step S8, that is, the corrected angular displacement signal is D /
Converted to analog signal by A converter 7 or PW
It is output from the microcomputer COM2 as a pulse output of M or the like.

Since the HPF 10, the integrator circuit 5, and the phase and gain correction circuit 11 use digital filters and the like, the sampling time must be relatively high (for example, about 1 kHz), but panning / tilting and photographing are performed. The determination circuit 12 that determines the state and the frequency detection unit 13 may perform processing at a relatively slow cycle (for example, 100 Hz). In other words, it can be changed according to the situation.

Here, the holding means 13 in this embodiment will be described. The holding means 13 shuts off the output from the sensor until the sensor output stabilizes when the power is turned on or when the image stabilizing device enters the operating state and starts the shake correction operation. This is to maintain a stable state so as not to deal with the disturbed sensor output at the time of turning on.

FIG. 10 shows the flow. In S11, the power is turned on (or the operation of the circuit that constitutes the vibration isolation device is turned on), the count is started in S12, and in S13 it is determined whether the count value is a predetermined value or not, and if it does not reach that value, the sensor is detected in S14. The output is shut off, the correction means is stabilized, and the process returns to S12 to add a count. If the count value has reached the predetermined value in S13, normal control is performed in S15.

(Second Embodiment) FIG. 11 shows a third embodiment of the present invention.

The invention in this embodiment is the same as the one shown in the first embodiment in terms of the intended content,
This is shown as a specific example having a different circuit configuration, and the description of the same parts will be omitted.

11 is different from the first embodiment shown in FIG. 1 in that the means for changing the characteristics for phase correction and gain correction (the resistance value for setting the time constant of the HPF and the variable gain amplifier, respectively). The analog switches 28 and 27 are used to change the resistance value for gain setting).
The point is that the resistance value is substantially varied by PWM-controlling the duty ratio of N · OFF by the PWM generation circuit 29.

Therefore, the system itself is the same as that of the first embodiment shown in FIG. 1, and controls the shutoff means 14 according to the output of the holding means 13 to shut off the sensor output when the power is turned on and stabilize the correction means. .

(Third Embodiment) FIG. 12 shows a third embodiment of the present invention.

The holding means 13 in this embodiment is provided with a time measuring means 17, and by interrupting the output from the sensor until the sensor output stabilizes when the power is turned on, the correction means when the power is turned on. It is kept in a stable state so as not to deal with disturbed sensor output.

FIG. 13 shows a flow chart showing the operation of the holding means.

In step S21, the power is turned on (or the operation of the circuit constituting the image stabilizing device is turned on), the timer is started in step S22, and it is determined in step S23 whether the timer value is a predetermined value. S2
At 4, the sensor output is cut off to stabilize the correction means and S
Return to 22 and add time. If the timer value has reached the predetermined value in S23, normal control is performed in S25.

[0055]

As described above, according to the shake correction apparatus of the present invention, the shake correction is performed when the apparatus is powered on or immediately after the prevention operation is started and the system is unstable. Since the means is forcibly held in a stable state and the detection output of the sensor is cut off, the power is turned on.
At this time, it is possible to prevent malfunction of the shake correction device and display of an unstable image in an unstable state at the start of the image stabilization operation, and it is possible to always obtain a high quality image output.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a shake correction photographing apparatus according to the present invention.

FIG. 2 is a flow chart for explaining the operation of the first embodiment of the shake correction photographing apparatus of the present invention.

FIG. 3 is a diagram showing a configuration of a lens unit provided with an optical shake correcting means using a variable apex angle prism.

FIG. 4 is a block diagram of a drive system of a variable apex angle prism.

FIG. 5 is a diagram showing another example of a lens unit provided with an optical shake correcting means using a variable apex angle prism.

FIG. 6 is a block diagram of a drive system that drives the optical shake correction unit shown in FIG.

FIG. 7 is a diagram for explaining the configuration and operation of a variable apex angle prism.

FIG. 8 is a diagram for explaining the configuration and operation of the variable apex angle prism.

FIG. 9 is a block diagram showing a configuration of an electronic shake correction unit by image processing.

FIG. 10 is a flow chart for explaining the operation of the holding means of the shake correction apparatus according to the present invention.

FIG. 11 is a block diagram showing a second embodiment of the shake correction photographing apparatus of the present invention.

FIG. 12 is a block diagram showing a third embodiment of the shake correction photographing apparatus of the present invention.

FIG. 13 is a flow chart for explaining the operation of the holding means of the shake correction apparatus according to the present invention.

FIG. 14 is a block diagram showing an example of a conventional shake correction apparatus.

Claims (3)

[Claims] 1. A detection means for detecting a vibration of an apparatus, a correction means for correcting a movement of an image due to the vibration, and a direction for controlling the correction means based on an output of the detection means to correct the movement of the image. First control means for operating the correction means, a shooting state determination means for determining a shooting state from the output of the first detection means, and the first control means based on the output of the shooting state determination means A shake control means for controlling the characteristics of the correction means, and a holding means for holding the correction means in a stable state for a predetermined period until the output of the detection means stabilizes when the power is turned on. Correction device. 2. The cut-off means for cutting off a signal from the detection means according to claim 1, wherein the cut-off means cuts off the signal until the output of the shake detection means stabilizes when the power is turned on. A shake correction device having a holding function for keeping the correction means in a stable state. 3. A detection means for detecting a vibration of the apparatus, a correction means for correcting a movement of an image due to the vibration, and a direction for controlling the correction means based on an output of the detection means to correct the movement of the image. First control means for operating the correction means, a shooting state determination means for determining a shooting state from the output of the first detection means, and the first control means based on the output of the shooting state determination means A second control means for controlling the characteristics of the above, and a holding means for holding the correction means in a stable state for a predetermined period until the output of the detection means stabilizes at the start of the image stabilization operation. Shake correction device.