JP2000066259A - Image pickup device and method for controlling lens position in the image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid an impact noise from being produced even when a power source is turned off as far as possible and to prevent an unnatural video from being outputted and recorded. SOLUTION: When turning off the power source is required (S4), whether or not F1 is set to '1' is judged. When the answer is negative(No), a counter is incremented and the execution of lens moving processing is awaited in a specified term (S6→S7→S8). After F1 is set to '1', vibration-proof control is stopped (S9), and when F2 and F3 are not set to '1', operation is restored to S2 after a specified value X is set to a value 'R' and a shift lens is made to come close to the vicinity of the inner wall of a lens barrel(S10→...→S13→S 19). When F2 is set to '1' the specified value X is subtracted by a fine amount ΔR so as to make the shift lens gradually come close to the inner wall of the lens barrel. When the specified value X reaches the lowest value LLMT, the shift lens is judged to abut on the lens barrel (S11→S14→...→S19).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus and a method of controlling a lens position in the image pickup apparatus. More specifically, the present invention relates to an image pickup apparatus having a shake correction function for correcting a shake of an apparatus main body at the time of image pickup, and The present invention relates to a method for controlling a lens position of a movable lens mounted on an apparatus.

[0002]

2. Description of the Related Art In an image pickup apparatus such as a small video camera, it is known that an image of a subject shakes due to so-called camera shake or vibration, so that an image which is hard to appreciate is sometimes output or recorded. .

[0003] In particular, it has become common today in this type of image pickup apparatus to mount a zoom lens capable of continuously changing the focal length without changing the image point position. Although imaging devices having a high zoom magnification of 10 times or more are widely available on the market, there is a drawback that when a subject is imaged on the telephoto side where the zoom magnification is large, a remarkable subject image shake can occur.

Therefore, as a measure for solving such a drawback, an image pickup apparatus equipped with an image pickup optical system having shake correction means has been conventionally developed and already commercialized.

FIG. 9 is a conceptual diagram schematically showing the image pickup optical system. The image pickup optical system 100 includes a fixed lens 101 fixed to a lens barrel (not shown), and an arrow a. Zoom lens 102 moving horizontally on optical axis C
And in a plane perpendicular to the optical axis C (the direction indicated by the arrow b)
A shift lens 103 that moves two-dimensionally, a focus lens 104 that corrects movement of a focal plane due to a focus adjustment function and movement of the zoom lens 102, and an image sensor 105 on which a subject image is formed. Arranged in
Further, at a predetermined position near the shift lens 103, an actuator 106 for driving the shift lens 103 and a position detection sensor 10 for detecting the position of the shift lens 103 are provided.
7 are provided.

In the image pickup optical system 100, FIG.
As shown in FIG. 10A, even when the optical axis C is deviated from the central axis C ′ of the imaging optical system due to camera shake and the like, and the deviation angle θ is generated, the actuator 106 is driven to drive the optical axis C in FIG.
By moving the shift lens 103 as shown by the imaginary line in (b), the optical axis C and the center axis C ′ of the imaging optical system can be geometrically matched on the downstream side of the shift lens 103. Therefore, the above-mentioned shift angle θ is corrected by optical processing, and the subject image is formed on the image sensor 105 as a light beam without shake.

FIG. 11 is a block circuit diagram of a conventional image pickup apparatus which performs shake correction via the image pickup optical system 100.

In the image pickup apparatus, the power switch 1
When 08 is turned on, the mode microcomputer 109 notifies the main microcomputer 110 that the power switch 108 is turned on, and the main microcomputer 110 determines that the power is turned on and starts control.

Then, a shake signal generation circuit 111 which detects a shake of the apparatus main body generates a shake signal to generate a shake correction circuit 1.
Input to 12. The shake correction circuit 112 converts an analog shake signal into a digital shake signal with an A / D converter 113, removes a predetermined low-frequency component with a high-pass filter (HPF) 114, and then converts the phase / gain correction circuit 1
At 15, the phase and gain of the output signal from the HPF 114 are corrected, and the output signal from the phase / gain correction circuit 115 is integrated by the integration circuit 116 to calculate and output a correction target value.

The correction target value output from the shake correction circuit 112 is converted into an analog signal by the D / A converter 117, input to the adder 118, and supplied from the position detection sensor 107 supplied through the amplifier 119. Is added to the feedback signal. Next, the output signal from the adder 118 is supplied to the drive circuit 120, which issues a drive signal to the actuator 106 and outputs the drive signal to the shift lens 10.
3 is driven.

When the shift lens 103 is driven by the actuator 106 in this manner, the shift angle θ is optically corrected as described above, and the subject image is formed on the image sensor 105 as a light beam having no shake. Will be done.

The electric signal photoelectrically converted by the image pickup device 105 is supplied to a video signal processing circuit 122 via a camera signal processing circuit 121, and a video signal from the video signal processing circuit 122 is output to an output terminal 123. While the video signal is visualized on the display screen, the video signal is transmitted as an image information via the RF signal to the recorder 124.
Is recorded on a recording medium such as a magnetic tape.

In the above-described image pickup apparatus, the actuator 106 for driving the shift lens 103 is constituted by a voice coil motor.

That is, a voice coil motor is provided at a predetermined position in the vicinity of the shift lens 103, and a current is applied to the voice coil motor to generate an electromagnetic force so that the shift lens 103 is floated. By making the electromagnetic force variable according to the output, the shift lens 103 moves two-dimensionally in a vertical direction (pitch direction) and a horizontal direction (yaw direction) in a plane perpendicular to the optical axis C.

[0015]

However, in the conventional imaging apparatus, as described above, since the actuator 106 is constituted by a voice coil motor, when the power switch 108 is turned on and the power is on, The shift lens 103 is held floating by the voice coil motor, but when the power is turned off, the holding force of the shift lens 103 by the voice coil motor is released and the shift lens 103 falls by its own weight, and as a result, the shift lens 103 is held. However, there is a problem that the lens holding frame hits against the inner wall of the lens barrel and generates an unpleasant collision sound.

Further, since the optical axis C is decentered due to the movement of the shift lens 103, for example, when the power is turned off during the image pickup operation of the image pickup device, an image having an unnatural movement is output or the image is recorded on the recording medium. There was a problem of being recorded.

The present invention has been made in view of such a problem, and it is possible to minimize the occurrence of a collision sound even when the power is turned off, and to reduce the possibility that the power is turned off during imaging. It is an object of the present invention to provide an imaging device that does not output or record unnatural video even if it is present, and a method of controlling a lens position in the imaging device.

[0018]

In order to achieve the above object, an image pickup apparatus according to the present invention comprises: an image pickup lens group including at least a movable lens moving in a plane perpendicular to an optical axis; Photoelectric conversion means for converting an optical signal transmitted through the optical signal into an electric signal, signal output means for performing predetermined signal processing on the electric signal output from the photoelectric conversion means, and a shake detection means for detecting the shake of the apparatus body, A lens driving unit that electromagnetically floats the movable lens, a driving amount control unit that controls a driving amount of the lens driving unit according to a detection result of the shake detection unit, and the device body issues a stop request Output switching means for controlling the output signal of the signal output means to a predetermined level in the case; and when the apparatus main body issues a stop request, the image pickup is performed instead of the control by the drive amount control means. Is characterized by having a progressively closer lens movement control means said movable lens to the inner wall of the lens barrel arranged lens group.

A method of controlling a lens position in an imaging apparatus according to the present invention includes an imaging lens group including at least a movable lens moving in a plane perpendicular to an optical axis, and an optical signal transmitted through the imaging lens group. After converting to an electrical signal, applying a predetermined signal processing to the electrical signal to generate a video signal, detect the shake of the device body, electromagnetically float the movable lens, drive the movable lens, In a method of controlling a lens position in an imaging apparatus that executes a driving amount control process for controlling a driving amount of the movable lens according to a shake of the apparatus main body, when the apparatus main body issues a stop request, the image is displayed. A signal is controlled to a predetermined level, and a lens moving process for gradually bringing the movable lens closer to an inner wall of a lens barrel in which the imaging lens group is arranged is executed.

The other features of the present invention will be apparent from the following description of embodiments of the present invention.

[0021]

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

FIG. 1 is a schematic diagram showing one embodiment of an image pickup optical system mounted on an image pickup apparatus according to the present invention.
The imaging optical system 1 includes a fixed lens 3 fixed to a lens barrel 2 and receiving a light signal from a subject image, a zoom lens 5 that moves on an optical axis 4 in a horizontal direction to zoom the subject image. A diaphragm 6 for adjusting the amount of incident light, and two-dimensionally moving in a vertical direction (hereinafter, referred to as "pitch direction") and a lateral direction (hereinafter, referred to as "yaw direction") in a plane perpendicular to the optical axis 4. A shift lens 7 for decentering the optical axis, a focus lens 8 for correcting a focus shift caused by a focus adjustment and a movement of the zoom lens 5, a focusing and focusing of a subject image, and converting an optical signal into an electric signal. And an image pickup device 9 such as a CCD.

The imaging optical system 1 detects voice coil motors 10p and 10y as actuators for driving the shift lens 7 in the pitch direction and the yaw direction, and detects the position of the shift lens 7 in the pitch direction and the yaw direction. It has Hall elements 11p and 11y as position detection sensors.

More specifically, the shift lens 7, the voice coil motors 10p and 10y, and the hall elements 11p and 11y
Is disposed between the diaphragm 6 and the focus lens 8, and the shake prevention unit 12 prevents the shake caused by the camera shake or the like.

FIG. 2 is a perspective view of the anti-vibration unit 12.

In FIG. 1, reference numeral 13 denotes a lens holding frame, and the shift lens 7 is a cylindrical portion 14 of the lens holding frame 13.
Is held.

Further, three holes 15a, 1a at 120 ° intervals around the optical axis 4 are formed in the outer peripheral portion of the lens holding frame 13.
5b and 15c are formed. The substantially cylindrical guide pins 16a, 16b, and 16c are provided in the holes 15a, 15a.
b, 15c are pressed into or adhered to the guide pins 16a,
16b and 16c are integrally held by the lens holding frame 13.

Reference numeral 18 denotes a guide plate which is formed in a substantially rectangular shape, and has holes 19a, 19b, 20a, and 20b formed in the vicinity of the corners of the guide plate 18 and formed in a radially elongated shape.
Are formed.

Reference numeral 23 denotes an intermediate lens barrel. The intermediate lens barrel 23 has a guide portion (not shown) protruding from a surface facing the lens holding frame 13. Is formed with an elongated hole in the circumferential direction.

The guide pins 16a, 16b, and 16c are engaged with holes formed in the guide portion of the intermediate lens barrel 23, and project from the surface of the lens holding frame 13 facing the guide plate 18. The pins 22a, 22b are
8 are engaged with the holes 19a and 19b of the
A pin (not shown) protruding from the third guide plate 18 on the facing surface side is engaged with the holes 20a and 20b of the guide plate 18. Thus, the lens holding frame 13 is positioned relative to the intermediate lens barrel 23 in the rotation direction (roll direction) with respect to the optical axis 4, and is guided so as to be rotatable only in the pitch direction and the yaw direction.

The two magnets 25p, 25y to which the back yokes 24p, 24y are fixed are housed in the recesses 26p, 26y of the intermediate lens barrel 23 so as to be orthogonal to each other. It is fixed. Further, the upper yoke 27 is fixed to the intermediate lens barrel 23 with a certain interval from the magnets 25p and 25y, and the back yoke 24p,
A magnetic circuit is formed by 24y, magnets 25p and 25y, and upper yoke 27. And the coils 28p, 2
Reference numeral 8y denotes a lens holding frame 1 which is opposed to the magnets 25p and 25y and has a certain distance from the magnets 25p and 25y.
3 is fixed. Then, the back yokes 24p, 24
y, the magnets 25p and 25y, the upper yoke 27 and the coils 28p and 28y, and the voice coil motors 10p and 10y.
1 (see FIG. 1), which are arranged in directions orthogonal to each other, and which cause current to flow through the coils 28p and 28y to generate an electromagnetic force, thereby causing the shift lens 7 to pitch in a plane perpendicular to the optical axis 4. A buoyancy force for moving two-dimensionally in the direction and the yaw direction is generated. That is, the coil 28p,
An electromagnetic force is generated by passing a current through 28y, and the combined force acts on the lens holding frame 13, and the shift lens 7 is driven and held in the pitch direction and the yaw direction.

Reference numeral 29 denotes a sensor holder, on which the Hall elements 11p and 11y are mounted and the sensor holder 29 is fixed to the intermediate lens barrel 23. Further, magnets 17p and 17y to which yokes 17ap and 17ay are attached are fixed to the lens holding frame 13. The magnets 17 p and 17 y are magnetized so as to have a magnetic gradient in the driving direction of the lens holding frame 13, and
1p and 11y are arranged at a fixed distance from the magnets 17p and 17y, and the Hall elements 11p and 11y position the shift lens 7 (lens holding frame 13) based on a change in magnetic flux accompanying the movement of the magnets 17p and 17y. Is detected.

FIG. 3 is a block diagram showing a control system of the image pickup apparatus according to the present invention. The image pickup apparatus includes the image pickup optical system 1 and a shake detecting a shake of the apparatus main body and generating a shake signal. A signal generation circuit 30, a drive amount control unit 31 for controlling a drive amount of the shift lens 7 based on an output result from the shake signal generation circuit 30, a mode microcomputer 32 for monitoring an operation state of the apparatus main body, Switch 33 for turning on the power to the apparatus, a main microcomputer 34 for controlling the entire apparatus, and D / A converters 35p and 3 for converting a digital output signal from the drive amount control unit 31 into an analog output signal.
5y, amplifiers 36p and 36y for amplifying output signals from the Hall elements 11p and 11y, and the amplifiers 36p and 36y.
y and the D / A converter 35
p, an adder 37p for adding the output signal from 35y,
37y, driving circuits 38p and 38y for driving the voice coil motors 10p and 10y based on the output signals from the adders 37p and 37y, and an image for subjecting the electric signal photoelectrically converted by the imaging device 9 to predetermined image processing. Processing circuit 3
9, an output terminal 40 for outputting image data processed by the image processing circuit 39 to a display device (not shown) such as an LCD, and recording the processed image data on a recording medium such as a magnetic tape. And a recorder 41 for performing the operation.

More specifically, the shake signal generating circuit 30 is provided at an appropriate position in the imaging optical system 1 and detects angular shake sensors 42p and 42y for detecting the shake angle of the apparatus main body, and the angular speed sensors 42p and 42y. A high-pass filter (HPF) 43p for removing a DC component from the output detection signal,
43y, amplifiers 44p and 44y for amplifying output signals from the HPFs 43p and 43y, and the amplifiers 44p and 44y
Low-pass filter (LPF) 45 for removing a predetermined high frequency component from the output signal from
p, 45y.

The image processing circuit 39 performs a predetermined imaging process on the electric signal photoelectrically converted by the imaging device 9 to generate a camera video signal.
A predetermined video processing is performed on the camera video signal output from the camera signal processing circuit 46 to generate a video video signal, or the generated video video signal
A video signal processing circuit 47 that converts the signal into a (Radio Frequency) signal and outputs the RF signal to the recorder 41, and an output signal switching circuit 48 that switches the output signal.

As shown in FIG. 4, the output signal switching circuit 48 has a signal generator 49 for generating a black signal as a predetermined luminance level signal and a changeover switch 50. , A video signal is input, a black signal from the signal generator 49 is input to a contact b of the changeover switch 50, and an output signal from the main microcomputer 34 is input to a contact c of the changeover switch 50. Then, according to the output result from the main microcomputer 34, the c contact of the changeover switch 50 is connected to the a contact or the b contact, and the video image signal or the black signal is output to the output signal switching circuit 48.
Will be output. In this embodiment, the predetermined luminance level signal output from the signal generator 49 is a black signal. However, a specific color signal such as a white signal other than the black signal may be used.

Further, as shown in FIG. 5, the drive amount control section 31 includes an A / D converter 5 for converting an analog shake signal output from the shake signal generation circuit 30 into a digital shake signal.
1p, 51y and an HPF for removing a predetermined low frequency component from the output signals from the A / D converters 51p, 51y.
52p and 52y, phase and gain correction circuits 53p and 53y for correcting the phase and gain of the output signals from the HPFs 52p and 52y, and phase and gain correction circuits 53p and 53y.
Integrating circuits 54p and 54y for integrating the output signals from the camera and generating correction target values for performing image shake correction, and a desired lens movement target value (predetermined value independent of the shake signal from the shake signal generation circuit 30). A predetermined value output circuit 55 for outputting the value X), and a changeover switch 56 for switching respective output signals from the integration circuits 54p and 54y and the predetermined value output circuit 55.
And The contact a of the switch 56 is connected to the integrating circuit 54, the contact b of the switch 56 is connected to the predetermined value output circuit 55, and the contact c of the switch 56
The contact is connected to the mode microcomputer 32. And
In response to a signal from the mode microcomputer 32 monitoring the state of the power switch 33, the c contact of the changeover switch 56
The changeover switch 56 outputs a correction target value from the integration circuits 54p and 54y or a predetermined value X from a predetermined value signal output circuit 55.

In the imaging apparatus thus configured, when the power switch 33 is turned on, the mode microcomputer 32 notifies the main microcomputer 34 that the power switch 33 is turned on, and the main microcomputer 34 turns on the power. It is determined that the control has been performed, and the control is started.

When the angular velocity sensors 42p and 42y detect the shake of the apparatus main body, the HPFs 43p and 43y, the amplifiers 44p and 44y, and the LPFs 45p and 45y perform predetermined processing to generate a shake signal. It is supplied to the unit 31. The drive amount control unit 31 calculates a correction target value via the A / D converters 51p and 51y, the HPFs 52p and 52y, the phase / gain correction circuits 53p and 53y, and the integration circuits 54p and 54y, and calculates the calculated correction target value. Is output to the D / A converters 35p and 35y via the changeover switch 56.

Next, the correction target values converted into analog signals by the D / A converters 35p and 35y are added to the adders 37p and 37p, respectively.
7y, and are added to the feedback signals from the Hall elements 11p and 11y supplied through the amplifiers 36p and 36y. Next, output signals from the adders 37p and 37y are supplied to drive circuits 38p and 38y, and the drive circuits 38p and 38y output the voice coil motors 10p and 10y.
A drive signal is issued at y to drive the shift lens 7 two-dimensionally and vertically in a plane perpendicular to the optical axis 4 to capture a subject image.

The picked-up subject image is taken by the image pickup device 9.
The photoelectrically converted electric signal is formed into a camera signal processing circuit 46 and a video signal processing circuit 4.
7. The signal is output to the output terminal 40 via the output signal switching circuit 48, is visually displayed on a display device such as an LCD, and the RF signal is transmitted from the video signal processing circuit 47 to the recorder 41, and the video image signal is transmitted to a magnetic tape or the like. It is recorded on a recording medium.

On the other hand, when the power switch 33 is switched from the on state to the off state, the switching state is notified to the mode microcomputer 32 and further to the main microcomputer 34. When the main microcomputer 34 receives the notification from the mode microcomputer 32, the main microcomputer 34 cuts off the output of the RF signal output from the video signal processing circuit 47 to stop the recording operation of the recorder 41, and switches the switch of the output signal switching circuit 48. The power switch 33 is notified to the c-contact of 50 that the power switch 33 has been turned off. And thereby, the changeover switch c
The contact is switched from the contact a to the contact b, and the output terminal 40 is supplied with a black signal from the signal generator 49.

Next, after the power switch 33 is switched from the ON state to the OFF state as described above, the switch 56 of the drive amount control unit 31 is switched from the integration circuit 54 to the predetermined value output circuit 55 after a predetermined period has elapsed. Switch. That is, even if the power switch 33 is switched from the on state to the off state, the recording operation from the video signal processing circuit 47 to the recorder 41 is stopped for a predetermined period (for example, 20 V (vertical synchronization) (NT
SC requires about 16.7 msec, and PAL requires 20 msec). Therefore, after the lapse of the predetermined period, the changeover switch 56 of the drive amount control unit 31 is switched from the integration circuit 54 to the predetermined value output circuit 55.
Switch to the side. As a result, the drive amount control section 31 outputs the predetermined value X instead of the correction target value, and the shift lens 7 is driven based on the predetermined value X.

FIG. 6 is a flowchart of a method for controlling the lens position according to the present invention. This program is executed by the drive amount control unit 31.

In step S1, the system is initialized.
In addition, the initialization processing includes first to third flags F to be described later.
1 to F3 are cleared to "0".

Next, in step S2, the process waits until the vertical scanning is synchronized. The following processing is executed once in one field by this vertical synchronization.

In step S3, communication with the mode microcomputer 32 is performed. That is, information exchange such as a vibration-proof on / off request, a power-off request, and a power-off flag FOFF for permitting power-off is performed with the mode microcomputer 32.

Then, in step S4, it is determined through communication with the mode microcomputer 32 whether or not a power-off request has been made. If the answer to step S4 is affirmative (Yes), the process proceeds to step S5, where the first flag F1 is set to "1".
It is determined whether or not is set. In the first loop, since the first flag F1 has been cleared to "0" in step S1, the answer in step S5 is negative (No),
Proceeding to step S6, after incrementing the count value CN of the counter incorporated in the drive amount control unit 31 by "1", proceeding to step S7, it is determined whether or not the count value CN is at least equal to or greater than the set value C. . Here, the setting value C is, for example, 20 V (N) according to the recording state of the recorder 41 when the power-off request is made, as described above.
The value is set to a value corresponding to a predetermined time required for elapse of about 16.7 msec for TSC and 20 msec for PAL.
If the answer to step S7 is negative (No), the process returns to step S2 and repeats the above-described processing until a predetermined period in which the count value of the counter reaches the set value C has elapsed.
When the count value CN of the counter reaches the set value C, the process proceeds to step S8, sets the first flag F1 to "1", and returns to step S2.

As described above, the first flag F1 is set to "1".
If the answer is YES, the answer to step S5 is affirmative (Yes), and the process proceeds to step S9, where the image stabilization control is stopped. That is, the switch 56 is switched from the integration circuits 54p and 54y to the predetermined value output circuit 55.

Then, the process proceeds to step S10, where it is determined whether or not the second flag F2 is set to "1". In this loop, the second flag F2 is set to "0" in step S1. Is maintained, the answer to step S10 is negative (No), and the process proceeds to step S11 to determine whether the third flag F3 is set to "1". Also in this case, the third flag F3
Keeps the state set to "0" in step S1, the answer to step S11 is negative (No), the process proceeds to step S12, and the predetermined value X is set to the value "R". Here, the value “R” is set to a value at which the outer peripheral portion of the lens holding frame 13 holding the shift lens 7 does not contact the inner wall of the lens barrel 2.

Next, in step S13, the third flag F3 is set to "1", and the output value OU of the drive amount control unit 31 is set.
A predetermined value X (= R) is output as T, and step S2 is performed again.
Return to As a result, the lens holding frame 13 instantaneously moves to near the inner wall of the lens barrel 2.

Thus, the third flag F3 is set to "1".
Is set in step S11 in the next and subsequent loops.
Is affirmative (Yes), and proceeds to step S14.
A value obtained by subtracting the small amount ΔR from the predetermined value X is reset to the predetermined value X, and in the following step S15, it is determined whether or not the predetermined value X has become equal to or less than the minimum value LLMT. If the answer is negative (No), the process proceeds to step S19, where the output value OUT of the drive amount control unit 31 is a predetermined value X (= X−Δ
R), and returns to step S2.

The predetermined value X is at least the minimum value LL.
The above processing is repeated until the lens reaches the MT, and when the predetermined value X becomes equal to or less than the minimum value LLMT, the lens holding frame 13 is moved to the lens barrel 2.
Is determined to have been obtained, and the predetermined value X is set to the minimum value LLMT in step S16, and then the second flag F is set.
2 is set to "1", a power-off flag FOFF for permitting power-off is set to "1" in the subsequent step S18, a predetermined value X is output as the output value OUT of the drive amount control unit 31, and the process returns to step S2. . Thereby, the imaging optical system 1 stops driving.

If it is determined in step S4 that there is no power-off request, that is, if the power switch 33 is not turned off, the process proceeds to step S20, where the count value CN of the counter is cleared to "0". Step S2
At 1, it is determined whether or not the first flag F1 is set to "1". If the answer is negative (No), the process returns to step S2, while the answer in step S21 is affirmative (Y
In the case of es), the first to third flags F1 to F3 are set to “0”.
(Step S22), the power-off flag F
OFF is cleared to "0" (step S23, anti-vibration control is started (step S24), and the process returns to step S2. That is, the changeover switch 56 is moved from the predetermined value output circuit 55 to the integration circuits 54p, 54y). Switching and output of a target correction value from the drive amount control unit 31 to control the drive amount of the shift lens 7 during imaging.

FIG. 7 is a diagram showing a driving state of the lens holding frame 13 after the power-off request is issued. When a predetermined period of time, for example, 20 V elapses after the power-off request is issued, the lens holding frame 13 is turned off. The position 13 moves from the position indicated by the solid line to the position indicated by the dashed line (movement amount R), and then moves to the side of the lens barrel 2 with the minute amount ΔR (ΔR × n), and finally the two-dot chain line As shown in (2), the lens holding frame 13 comes into contact with the lens barrel 2, and then the power is turned off.

As described above, in this embodiment, when the mode microcomputer 32 detects that the power switch 33 has been turned off, the main microcomputer 34 stops the recording operation of the recorder 41 and switches the output signal switching circuit 48 to the video signal processing circuit. 47
Side to the signal generator 49 side to output a black signal, and after a predetermined period elapses, the lens holding frame 13 is instantaneously moved from the optical axis 4 to a position corresponding to the set value R.
Since the moved lens holding frame 13 is gradually moved to the vicinity of the inner wall of the lens barrel 2 so that the lens holding frame 13 comes into contact with the inner wall of the lens barrel 2, the shift lens 7 which has been in a floating state due to the anti-vibration control. To prevent the shift lens 7 from dropping by its own weight even when the power is turned off and generating an unpleasant collision sound between the lens holding frame 13 holding the shift lens 7 and the inner wall of the lens barrel 2. In addition, it is possible to prevent an unnatural image movement due to eccentricity of the optical axis 4 during movement of the shift lens 7 when the power is turned off from being output on a display screen or recorded on a magnetic tape. it can.

The present invention is not limited to the above embodiment. In the above-described embodiment, it is determined that a power-off request has been made by detecting that the power switch has been turned off. However, when the remaining amount of the battery mounted on the imaging device becomes equal to or less than a predetermined value, the power is turned off. It may be determined that an off request has been made.

As another embodiment, for example, the main microcomputer 34 constantly monitors the recorder 41, and when the mode microcomputer 32 detects a power-off request, the drive amount control section is controlled in accordance with the recording operation state of the recorder 41. The switching timing of the changeover switch 56 in 31 may be switched.

FIG. 8 is a timing chart showing the operation when the power is turned off in another embodiment.

When the power switch 33 is turned off at time t1 (FIG. 8A), the mode microcomputer 32 notifies the main microcomputer 34 and the driving amount control unit 31 at time t2 that the power switch 33 is turned off. (FIG. 8 (b)).

When the recorder 41 is recording a video image signal on the magnetic tape, the main microcomputer 34 detects the stop of the recording mode (recorder mode) at a time t4 when a predetermined period T for completing the stop operation has elapsed. (FIG. 8
(C)) At the same time, the changeover switch 5 of the drive amount control unit 31
6 is switched to the predetermined value output circuit 55 side, and the amount of movement of the shift lens 7 at the time of a power-off request is controlled (FIG. 8D).
Then, the lens holding frame 1 holding the shift lens 7
At time t5 when the lens 3 comes into contact with the inner wall of the lens barrel 2 and the lens movement control ends, the power-off flag FOFF is set to “1” and an output for permitting power-off is performed (FIG. 8).
(E)).

On the other hand, the predetermined period T is a standby time for ending the recording operation on the magnetic tape of the recorder 41 after the power is turned off, so that the recording operation of the recorder 41 is not performed when the recorder 41 is not loaded with the magnetic tape. When not performing, there is no need to wait for a predetermined period. Therefore, in this case, the mode microcomputer 32 notifies the main microcomputer 34 and the drive amount control unit 31 that the power switch 33 is turned off at the time t2 (FIG. 8B), and at the same time, the main microcomputer 34 The stop of the recording mode (recorder mode) is detected as indicated by the broken line in (c), and the lens movement control of the shift lens 7 is started at this time t2 as indicated by the broken line in FIG. 8D. . And FIG.
As shown by the broken line in (e), the lens holding frame 13 is
At time t3 when the lens movement control is completed by contacting the inner wall of the camera, the power-off flag FOFF is set to "1", and an output for permitting power-off is performed.

As described above, when the main microcomputer 34 constantly monitors the recorder 41 and the mode microcomputer 32 detects the power-off request and the recorder 41 is not in the recording operation state, the lens movement control should be started early. Therefore, the time at which the power is turned off can be made earlier, and a power saving effect can be obtained.

[0064]

As described above in detail, according to the present invention, even if the power is switched from the on state to the off state, the movable lens which has been in a floating state due to the anti-vibration control drops by its own weight and the lens barrel is turned off. Unpleasant collision noise with the inner wall can be avoided, and unnatural image movement due to eccentricity of the optical axis during movement of the movable lens when the power is turned off is output on the display screen. Or recording on a magnetic tape can be prevented.

Further, the operation state of the recording means is constantly monitored, and the execution timing of the lens movement control means is determined in accordance with the operation state of the recording means. The execution can be started, whereby the time when the power is turned off can be made earlier, and a power saving effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an embodiment of an imaging optical system mounted on an imaging apparatus according to the present invention.

FIG. 2 is a perspective view of an anti-vibration unit disposed inside an imaging optical system.

FIG. 3 is a block diagram showing a control system of the imaging apparatus according to the present invention.

FIG. 4 is an electric circuit diagram showing details of an output signal switching circuit.

FIG. 5 is a block diagram showing details of a drive amount control unit.

FIG. 6 is a flowchart illustrating an embodiment of a method for controlling a lens position in the imaging apparatus according to the present invention.

FIG. 7 is a diagram showing a temporal change of a lens position of a shift lens when a power-off request is issued.

FIG. 8 is a flowchart illustrating another embodiment of a method for controlling a lens position in the imaging apparatus according to the present invention.

FIG. 9 is a diagram schematically illustrating a lens arrangement of a conventional imaging optical system.

FIG. 10 is a diagram for explaining a driving state of the shift lens when the optical axis is decentered from the center of the imaging optical system.

FIG. 11 is a block diagram showing a conventional control system of the imaging apparatus.

[Explanation of symbols]

Reference Signs List 4 optical axis 7 shift lens (movable lens) 9 image pickup device (photoelectric conversion unit) 10p, 10y voice coil motor (lens driving unit) 13 lens holding frame 31 drive amount control unit (drive amount control unit, lens movement control unit, stop) Means) 34 Main microcomputer (judgment means, monitoring means) 41 Recorder (recording means) 42 Angular velocity sensor (vibration detection means) 47 Video signal processing circuit (video signal output means) 48 Output signal switching means (output switching means)

Claims (19)

[Claims] An imaging lens group including at least a movable lens moving in a plane perpendicular to an optical axis; a photoelectric conversion unit configured to convert an optical signal transmitted through the imaging lens group into an electric signal; A signal output unit that performs predetermined signal processing on the electric signal output from the unit, a shake detection unit that detects a shake of the apparatus main body, a lens driving unit that electromagnetically floats the movable lens, and a shake detection unit. Drive amount control means for controlling the drive amount of the lens drive means in accordance with the detection result, and output switching means for controlling the output signal of the signal output means to a predetermined level when the apparatus main body issues a stop request When the apparatus main body issues a stop request, the movable lens gradually approaches the inner wall of the lens barrel in which the imaging lens group is arranged instead of the control by the drive amount control unit. An imaging apparatus comprising: lens movement control means. 2. The lens movement control means includes: first movement means for immediately driving the movable lens until near the inner wall of the lens barrel; and moving the movable lens near the inner wall by the first movement means. And second moving means for gradually moving the movable lens toward the inner wall until a lens holding frame for holding the movable lens comes into contact with the inner wall. An imaging device according to any one of the preceding claims. 3. The imaging apparatus according to claim 1, further comprising a stop unit that stops the apparatus main body after the control by the lens movement control unit is performed. 4. The apparatus according to claim 1, wherein the stop request is issued when a power switch for driving the apparatus main body is switched from an on state to an off state. Imaging device. 5. The imaging apparatus according to claim 1, wherein when the apparatus main body issues a stop request, the lens movement amount control unit is executed after a predetermined period has elapsed. . 6. A recording unit for recording an output signal of the signal output unit, and a monitoring unit for monitoring an operation state of the recording unit, wherein when the determination unit issues a stop request, the apparatus main body issues a stop request. The imaging apparatus according to claim 1, wherein an execution start timing of the lens movement control unit is determined according to an operation state of the recording unit monitored by the monitoring unit. 7. The monitoring means monitors whether or not the output signal of the signal output means is recording on the recording means, and varies the execution start timing of the lens movement control means depending on whether or not the recording is being performed. The imaging device according to claim 6, wherein: 8. An imaging lens group including at least a movable lens moving in a plane perpendicular to the optical axis, and converting an optical signal transmitted through the imaging lens group into an electric signal, A predetermined signal processing is performed to generate a video signal, a shake of the apparatus main body is detected, the movable lens is electromagnetically floated to drive the movable lens, and the movable lens is driven in accordance with the shake of the apparatus main body. In a method of controlling a lens position in an imaging device that executes a driving amount control process for controlling a driving amount, when the device main body issues a stop request, the image signal is controlled to a predetermined level, and the imaging lens group is controlled. A lens moving process for gradually moving the movable lens closer to the inner wall of the lens barrel provided with the lens. 9. The lens moving process includes: moving the movable lens immediately to a position near the inner wall of the lens barrel; and holding the movable lens after the movable lens has reached a position near the inner wall. 9. The method according to claim 8, wherein the movable lens is gradually moved to the inner wall side until the movable lens comes into contact with the inner wall. 10. The imaging apparatus according to claim 8, wherein the movable body is gradually moved to the inner wall side to stop the apparatus main body after the movable lens is brought into contact with the inner wall. A method for controlling a lens position in an apparatus. 11. The apparatus according to claim 8, wherein it is determined that the apparatus body has issued a stop request when a power switch for driving the apparatus body is switched from an on state to an off state. A method for controlling a lens position in the imaging device according to any one of the above. 12. The imaging apparatus according to claim 8, wherein when the apparatus main body has issued a stop request, the lens movement processing is performed after a predetermined period has elapsed. The method of controlling the lens position in. 13. An operation state of a recording unit for recording a video signal is monitored, and when the apparatus main body issues a stop request, an execution start timing of the lens moving process according to an operation state of the recording unit. 13. The method of controlling a lens position in an imaging device according to claim 8, wherein: 14. The apparatus according to claim 13, wherein whether or not a video signal is being recorded in said recording means is monitored, and the execution start timing of said lens movement processing is made variable depending on whether or not said recording is being performed. A method for controlling a lens position in an imaging device. 15. An imaging lens group including at least a movable lens moving in a plane perpendicular to an optical axis, a photoelectric conversion unit for converting an optical signal transmitted through the imaging lens group into an electric signal, and the photoelectric conversion. A signal output unit that performs predetermined signal processing on the electric signal output from the unit, a shake detection unit that detects a shake of the apparatus main body, a lens driving unit that electromagnetically floats the movable lens, and a shake detection unit. Drive amount control means for controlling the drive amount of the lens drive means in accordance with the detection result; and an output for shooting or fading the output signal of the signal output means to a predetermined level when the apparatus main body issues a stop request. Switching means, and when the apparatus main body issues a stop request, the control is performed by the drive amount control means instead of the drive amount control means. An imaging apparatus comprising: lens movement control means for gradually bringing a movable lens closer. 16. The lens movement control means includes: first movement means for immediately driving the movable lens up to near the inner wall of the lens barrel; and moving the movable lens near the inner wall by the first movement means. And a second moving means for gradually moving the movable lens toward the inner wall until a lens holding frame for holding the movable lens comes into contact with the inner wall after reaching the inner wall. An imaging device according to any one of the preceding claims. 17. The imaging apparatus according to claim 15, further comprising a stop unit that stops the apparatus main body after the control by the lens movement control unit is performed. 18. The apparatus according to claim 15, wherein when the apparatus main body issues a stop request, the lens movement amount control unit is executed after a predetermined period has elapsed.
The imaging device according to any one of the above. 19. A recording device for recording an output signal of the signal output device, and a monitoring device for monitoring an operation state of the recording device, wherein when the device main body issues a stop request by the determining device, The imaging apparatus according to claim 1, wherein an execution start timing of the lens movement control unit is determined according to an operation state of the recording unit monitored by the monitoring unit.