JP2000066260A - 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. SOLUTION: When turning off the power source is required(S7)t whether or not F1 and F2 are set to '1' is judged (S8 and S9). When the answer is negative(No), a target output value in a lateral direction is set to the center position of a shift lens (S10), a target output value in a longitudinal direction is set to a specified value A(S11) and then F1 is set to '1' (S12). When F1 is set to '1', a specified value A is subtracted by a fine amount ΔA so as to make the shift lens gradually come close to the inner wall of the lens barrel. When the specified value A reaches the lowest value LLMT, the shift lens is judged to abut on the lens barrel(S9→S13→...→S18).

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 recent years, in image pickup apparatuses such as cameras and video cameras, all functions such as exposure setting and focus adjustment have been automated and multi-functional, so that good photographing can be easily performed. It is becoming.

[0003] In a recent image pickup apparatus of this type,
It is common today to mount a zoom lens that can continuously change the focal length without changing the image point position. In recent years, imaging devices having a high zoom magnification of 10 times or more are also on the market. However, when the subject is imaged near the telephoto side where the zoom magnification is large, there is a disadvantage that a noticeable shake of the subject image occurs.

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. 12 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 10 moving horizontally on optical axis C
2, a shift lens 103 that moves two-dimensionally in a plane perpendicular to the optical axis C (in the direction indicated by the arrow b), and corrects the focus adjustment function and the movement of the focal plane due to the movement of the zoom lens 102. A focus lens 104 and an image sensor 105 on which a subject image is formed are arranged in this order, and an actuator 106 for driving the shift lens 103 is provided at a predetermined position near the shift lens 103.
And a position detection sensor 107 for detecting the position of the shift lens 103.

In the imaging optical system 100, FIG.
As shown in FIG. 13A, even when the optical axis C is deviated from the center 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
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. 14 is a block circuit diagram of a conventional image pickup apparatus that 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.

The shake signal generation circuit 111 which has detected the shake of the apparatus body generates a shake signal and inputs the shake signal to the shake correction circuit 112. 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 removes a phase / gain correction circuit 115. Then, 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.

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 near 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 floats. 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.

[0014]

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. The lens holding frame hits against the inner wall of the lens barrel, generating an unpleasant collision sound and lacking quality.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an image pickup apparatus capable of minimizing the generation of a collision sound even when the power is turned off, and a method of controlling a lens position in the image pickup apparatus. The purpose is to provide.

[0016]

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; Shake detection means for detecting, a lens drive means for electromagnetically floating the movable lens, a drive amount control means for controlling the drive amount of the imaging lens drive means according to the detection result of the shake detection means, A lens movement control unit that gradually moves the movable lens closer to the inner wall of the lens barrel in which the imaging lens group is arranged when the apparatus main body issues a stop request; It is characterized by.

A method of controlling a lens position in an image pickup apparatus according to the present invention includes detecting a shake of a main body of the apparatus, floating the movable lens electromagnetically, and moving the movable lens in a plane perpendicular to an optical axis. In a method of controlling a lens position in an imaging apparatus that performs 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, It is characterized in that a lens moving process for gradually bringing the movable lens closer to the inner wall of the lens barrel in which the lens is disposed is executed.

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

[0019]

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

FIG. 1 is a schematic diagram showing an 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. An aperture 6 for adjusting the amount of incident light, and a two-dimensionally vertical (hereinafter also referred to as “pitch”) and lateral (hereinafter also referred to as “yaw”) direction in a plane perpendicular to the optical axis 4. A shift lens 7 for moving the optical axis to decenter, a focus lens 8 for correcting a focus shift caused by the focus adjustment and the movement of the zoom lens 5, a focusing and focusing of a subject image, and an optical signal to an electric signal. And an image pickup device 9 such as a CCD for converting the image data into an image.

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.

The outer periphery of the lens holding frame 13 has three holes 15a, 1a at 120 ° intervals around the optical axis 4.
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 long hole shape.
Are formed.

Reference numeral 23 denotes an intermediate lens barrel, and a guide portion (not shown) protrudes from the intermediate lens barrel 23 on the side 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 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,
24y, magnets 25p and 25y, and upper yoke 27 form a magnetic circuit. Then, the coils 28p, 28
y is opposed to the magnets 25p, 25y at a certain interval from the magnets 25p, 25y.
To be fixed. Then, the back yokes 24p, 24y,
Magnets 25p, 25y, upper yoke 27 and coil 2
8p, 28y and voice coil motor 10p, 10y
1 (see FIG. 1), which are arranged in directions orthogonal to each other, and apply a current to the coils 28p and 28y to generate an electromagnetic force, thereby moving the shift lens 7 in a plane perpendicular to the optical axis 4 in the pitch direction. And a floating force for two-dimensionally moving in the yaw direction. That is, the coils 28p, 2
An electromagnetic force is generated by passing a current through 8y, 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. That is, the magnets 17p and 17y are magnetized so as to have a magnetic gradient in the driving direction of the lens holding frame 13, and the Hall elements 11p and 11y are connected to the magnets 17p and 1y.
7y and at a fixed interval, the Hall element 11p,
11y detects the position of the shift lens 7 (lens holding frame 13) based on a change in magnetic flux accompanying the movement of the magnets 17p and 17y.

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 D / A converters D / A converters 34p and 34y for converting a digital output signal from the drive amount control unit 31 into an analog output signal, and amplifies the output signals from the Hall elements 11p and 11y. The amplifiers 35p and 35y and the amplifier 3
5p, 35y, and adders 36p, 36y for adding the output signals from the D / A converters 34p, 34y, and the voice coil motor 10p, based on the output signals from the adders 36p, 36y. The drive circuits 37p and 37y for driving 10y are provided.

More specifically, the shake signal generation circuit 30 includes an angular velocity sensor 38p, 38y disposed at an appropriate position in the imaging optical system 1 for detecting a shake angle of the apparatus main body, and an angular velocity sensor 38p, 38y. A high-pass filter (HPF) 39p for removing a DC component from the output detection signal,
39y, amplifiers 40p and 40y for amplifying output signals from the HPFs 39p and 39y, and the amplifiers 40p and 40y
Low-pass filter (LPF) 41 for removing a predetermined high frequency component from the output signal from
p, 41y.

As shown in FIG. 4, the drive amount control unit 31 includes an A / D converter 42 for converting an analog shake signal output from the shake signal generation circuit 30 into a digital shake signal.
p, 42y and an HPF 4 for removing a predetermined low frequency component from the output signals from the A / D converters 42p, 42y.
3p, 43y and a phase / gain correction circuit 4 for correcting the phase and gain of the output signal from the HPF 43p, 43y.
4p and 44y; integration circuits 45p and 45y for integrating output signals from the phase / gain correction circuits 44p and 44y to generate correction target values for performing image shake correction; and shakes from the shake signal generation circuit 30. A predetermined value output circuit 46 for outputting a desired lens movement target value (predetermined value A) irrespective of the signal; integration circuits 45p and 45y and a predetermined value output circuit 4
And a changeover switch 47 for changing over the respective output signals from the control signal 6. The contact a of the switch 47 is connected to the integrating circuits 45p and 45y, the contact b of the switch 47 is connected to the predetermined value output circuit 46, and the contact c of the switch 47 is connected to the mode microcomputer 32.
Then, in response to a signal from the mode microcomputer 32 monitoring the state of the power switch 33,
The contact is connected to the a contact or the b contact, and the changeover switch 47
Outputs the correction target value from the integration circuits 45p and 45y or the predetermined value A from the predetermined value signal output circuit 46.

In the imaging apparatus thus configured, when the power switch 33 is turned on, the mode microcomputer 32 detects that the power switch 33 is turned on, and starts control.

When the angular velocity sensors 38p and 38y detect the shake of the main body of the apparatus, the HPFs 39p and 39y, the amplifiers 40p and 40y, and the LPFs 41p and 41y 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 42p and 42y, the HPFs 43p and 43y, the phase / gain correction circuits 44p and 44y, and the integration circuits 45p and 45y, and calculates the calculated correction target value. Are output to the D / A converters 34p and 34y via the changeover switch 47.

Next, the correction target values converted into analog signals by the D / A converters 34p and 34y are added to the adders 36p and 3p, respectively.
6y, and is added to the feedback signals from the Hall elements 11p, 11y supplied through the amplifiers 35p, 35y. Next, the output signals from the adders 36p and 36y are supplied to drive circuits 37p and 37y, and the drive circuits 37p and 37y
A drive signal is issued at y to drive the shift lens 7 two-dimensionally vertically and horizontally in a plane perpendicular to the optical axis 4 to capture a subject image.

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 the changeover switch 47 of the drive amount control unit 31 is switched.
Is switched from the integration circuit 45 side to the predetermined value output circuit 46 side. As a result, the drive amount control section 31 outputs the predetermined value A instead of the target correction value, and the shift lens 7 is driven according to the predetermined value A.

FIG. 5 is a flowchart of a lens position control method according to the present invention.

In step S1, the system is initialized.
Note that the initialization processing clears first and second flags F1 and F2 described later to “0”.

Next, in step S2, the shake signals generated by the shake signal generation circuit 30 are supplied to the HPFs 43p and 43y.
Performs predetermined filtering processing, and corrects the phase and gain by the phase / gain correction circuits 44p and 44y.
Integration is performed at 5p and 45y to calculate a correction target value at the time of shooting.

Next, in step S3, the first flag F
It is determined whether 1 is set to “1”. Then, in the first loop, the first flag F1 is set in step S1.
Is cleared to "0", the answer to step S3 is negative (No), and the process proceeds to step S4 to output a correction target value, and drives the shift lens to perform shake correction at the time of imaging.

In the following step S5, the mode microcomputer 32
It is determined whether or not a communication request has been made. If no communication request has been made, the process proceeds to step S7. If a communication request has been made, communication is executed (step S6), and then the process proceeds to step S7. That is, in step S6, communication is performed with the mode microcomputer 32 to exchange information such as a vibration-proof on / off request, a power-off request, and a power-off flag FOFF for permitting power-off.

In step S7, it is determined through a communication with the mode microcomputer 32 whether or not a power-off request has been made. It should be noted that whether or not a power-off request has been made is determined based on whether or not the power switch 33 is turned off.
If the answer to step S7 is affirmative (Yes), the process proceeds to step S8, and it is determined whether or not the second flag F2 is set to "1". In this loop, step S1
Since the state where the first flag F1 has been cleared to "0" is maintained in step S8, the answer in step S8 is negative (No), and in step S9 the first flag F1 is set to "1". It is determined whether or not. Similarly, in this loop, since the state where the first flag F1 is cleared to "0" in step S1 is maintained, step S9 is performed.
Is negative (No), and the process proceeds to step S10.

In the following step S10, the target output value in the horizontal direction (yaw direction) is set to be the center position of the shift lens 7, and in the following step S11, the target output value in the vertical direction (pitch direction) is set to a predetermined value A. Set. The predetermined value A 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. Then
In step S12, the first flag F1 is set to "1", and the process returns to step S2.

As described above, the first flag F1 is set to "1".
In the next and subsequent loops, the answer to step S3 and step S9 is affirmative (Yes), and the process proceeds to step S13 to reset a value obtained by subtracting the small amount ΔA from the predetermined value A to the predetermined value A. In the following step S14, it is determined whether or not the predetermined value A has reached the minimum value LMTA.
If the answer is negative (No), step S18
The target output value in the vertical direction is set to a predetermined value A.

On the other hand, when the predetermined value A reaches the minimum value LMTA, it is determined that the lens holding frame 13 has reached a value corresponding to the amount of movement of the lens barrel 2 in contact with the lens barrel 2, and the predetermined value A is reduced to the minimum value LMTA in step S15. After the setting, the second flag F2 is set to "1" in step S16, the power-off flag FOFF for permitting power-off is set to "1" in step S17, and the target output value in the vertical direction is set to a predetermined value. A (= LMT
A) is set (step S18), and the process returns to step S2. Thereby, the imaging optical system 1 stops driving.

If it is determined in step S7 that there is no power-off request, the flow advances to step S19 to determine whether the first flag F1 is set to "1". When the answer is negative (No), the process returns to step S2, and when the answer in step S19 is affirmative (Yes), the first and second flags F1, F2 and the power-off flag FOFF are set to "0". Clear (step S20) and restart the image stabilization control (step S21). That is, the changeover switch 47 is switched from the predetermined value output circuit 46 side to the integration circuit 45.
Switching to the p and 45y sides, the drive amount control unit 31 outputs a target correction value, and executes drive amount control of the shift lens 7 during imaging.

FIG. 6 is a view showing a driving state of the lens holding frame 13 after a power-off request is issued. When a power-off request is issued, the position of the lens holding frame 13 is shifted from the position shown by the solid line. Move to the position shown by the dashed line (movement amount A),
Then, it moves to the lens barrel 2 side for the minute amount ΔA (ΔA × n),
Finally, as shown by the two-dot chain line, 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 the off state of the power switch 33, the drive amount control unit 31 determines that a power-off request has been made, and moves the lens holding frame 13 to the optical axis 4 , The lens holding frame 13 is moved gradually to the vicinity of the inner wall of the lens barrel 2 so that the lens holding frame 13 contacts the inner wall of the lens barrel 2. Therefore, even if the power of the shift lens 7 which was in a floating state due to the image stabilization control is turned off, the shift lens 7 falls by its own weight and the lens holding frame 13 holding the shift lens 7 and the inner wall of the lens barrel 2. It is possible to avoid generating an unpleasant collision sound between the vehicle and the vehicle.

FIG. 7 is a block diagram showing a second embodiment of the present invention. In the drive amount control section 51, an anti-vibration off switch 52 is provided, and the amplifier 35, the drive amount control section 51 An electronic volume (EVR) 53 is interposed therebetween.

More specifically, as shown in FIG.
5 and the negative output terminal of the Hall element 10 are connected to the negative output terminal of the amplifier 35, while the positive output terminal of the amplifier is connected to the output signal from the positive output terminal of the Hall element 10 and the reference power supply VREF and VREF. An output signal from the EVR 53 is supplied.

When the power-on shake correction is being performed, the output signal from the EVR 53 is supplied to the amplifier 53 so as to compensate for the difference between the Hall element 10 and the reference power supply VREF.
On the other hand, when the power is turned off and a power-off request is issued, E is supplied in response to a request from the drive amount control unit 51.
The output signal of the VR 53 is variable, and the offset of the output of the Hall element 10 is adjusted.

FIG. 9 is a flowchart of a main part of the second embodiment.

As in the first embodiment (FIG. 5), each processing of steps S1 to S9 is executed, and step S9 is executed.
If the answer is negative (No), the power-off request has been issued in step S7, so that the anti-vibration off switch 52 is forcibly turned off in step S31. Thereby, the target output value in the lateral direction (yaw direction) is set to be the center position of the shift lens 7. Next, in step S32, the EVR initial data I in the vertical direction (pitch direction) is stored in the memory of the drive amount control unit 51. That is, as described above, the EVR 53 adjusts the offset of the output signal of the Hall element 10, and the data after the offset adjustment, that is, the initial data I is transmitted from the drive amount control unit 51 to the EVR 53 at the time of initial setting. Then, the initial data I is stored in the memory of the drive amount control unit 51.

Then, in step S12, the first flag F
1 is set to “1”, and the process returns to step S2.

As described above, the first flag F1 is set to "1".
In the next and subsequent loops, the answer to step S3 and step S9 is affirmative (Yes), the process proceeds to step S33, and a value obtained by subtracting the minute amount ΔD from the initial data I is set as a predetermined value C, and the subsequent step S34 Then, it is determined whether or not the predetermined value C is equal to or less than the minimum value LMTC. If the answer is negative (No), the process proceeds to step S38, where the target output value in the vertical direction is transmitted to the EVR 53 as the predetermined value C. After that, the above processing is repeated, and the EV
When the output value from the R53 gradually decreases, the output of the amplifier 35 also gradually decreases substantially in proportion, and the shift lens 7 gradually moves from the center position to the inner wall of the lens barrel 2.

On the other hand, when the predetermined value C becomes equal to or less than the minimum value LMTC, it is determined that the value corresponding to the amount of movement of the lens holding frame 13 in contact with the lens barrel 2 is determined, and the predetermined value C is reduced to the minimum value LMTC in step S35. After the setting, the second flag F2 is set to "1" in a step S36, the power-off flag FOFF for permitting the power-off is set to "1" in a succeeding step S37, and the target output value in the vertical direction is set to a predetermined value. C (= LMT
Set to C) and return to step S2. Accordingly, the driving of the imaging optical system 1 is stopped.

If it is determined in step S7 that there is no power-off request, the flow advances to step S19 to determine whether the first flag F1 is set to "1". When the answer is negative (No), the process returns to step S2, and when the answer in step S19 is affirmative (Yes), the first and second flags F1, F2 and the power-off flag FOFF are set to "0". Clear (step S40) and restart the image stabilization control (step S41). That is, the OFF state of the image stabilization off switch 52 is released, and the drive amount control unit 51
After that, the target correction value is output and the driving amount control of the shift lens 7 at the time of imaging is executed.

As described above, in the present embodiment, when the mode microcomputer 32 detects that the power switch 33 is turned off, the drive amount control unit 51 determines that a power-off request has been made, and transmits the initial data I of the EVR 53 to the drive data. Driving amount control unit 5
1 and the shift lens 7 is moved based on the initial data I, and then the set value C (= I−Δ
Since the lens movement is controlled based on D), EVR
The output signal from the amplifier 53 also gradually decreases, and the output signal from the amplifier 35 also decreases substantially in proportion to the output signal from the EVR 53. As a result, the lens holding frame 13 gradually moves near the inner wall of the lens barrel 2. The shift lens 7, which has been in a floating state due to vibration control, is dropped by its own weight and the lens holding frame holding the shift lens 7 even when the power is turned off. An unpleasant collision sound can be prevented from being generated between the lens 13 and the inner wall of the lens barrel 2.

FIG. 10 is a block diagram showing a third embodiment of the present invention.
A drive amount control unit 31 similar to that of the second embodiment is provided, and an EVR 53 is interposed between the amplifier 35 and the drive amount control unit 51 as in the second embodiment.
The feedback signal from 5 is also fed back to the drive amount control and 51 in addition to the adder 36.

FIG. 11 is a flowchart of a main part of the third embodiment.

First and second embodiments (FIGS. 5 and 9)
Similarly to the above, each processing of steps S1 to S9 is executed, and when the answer of step S9 is negative (No), the target output value in the lateral direction (yaw direction) becomes the center position of the shift lens 7 in step S51. Then, in step S52, the target output value in the vertical direction (pitch direction) is set to a predetermined value A, and in subsequent step S53, the EVR initial data I in the vertical direction (pitch direction) is transmitted to the drive amount control unit 31.
Then, in step S54, the first flag F1 is set to "1", and the process returns to step S2.

As described above, the first flag F1 is set to "1".
In the next and subsequent loops, the answer to step S3 and step S9 is affirmative (Yes), and the process proceeds to step S55 to detect the output of the Hall element 10, and the shift lens 7 (the lens holding frame 13) is detected in step S56. ) Is determined at the inner wall position of the lens barrel 2. That is, when the theoretical final position of the lens holding frame 13 holding the shift lens 7 exceeds the inner wall position of the lens barrel 2, power consumption is increased. Therefore, in the third embodiment, the position of the lens holding frame 13 can be stopped at the inner wall position of the lens barrel 2 by constantly monitoring the position of the shift lens 7 with the Hall element 11, and power consumption is reduced. Savings.

If the answer to step S56 is negative (N
In the case of o), the process proceeds to step S57, in which the value obtained by subtracting the minute amount ΔA from the predetermined value A is reset to the predetermined value A. In the following step S58, it is determined whether or not the predetermined value A has become equal to or less than the minimum value LMTA. I do. And the answer is negative (No)
In step S60, the process proceeds to step S60, in which a value obtained by subtracting the minute amount ΔD from the initial data I is set as a predetermined value C. In step S61, it is determined whether the predetermined value C is smaller than “0”. If the answer is negative (No), the process proceeds to step S63, where the target output value in the vertical direction is set to the predetermined value A, and the predetermined value C is transmitted to the EVR 53 in step S64, and the process returns to step S2.

On the other hand, the answer to step S58 is affirmative (Ye
s), the predetermined value A is reduced to the minimum value LL in step S59.
After setting to MT, the process proceeds to step S60 to execute the above-described processing, and the answer to step S61 is affirmative (Ye
At s), the predetermined value C is set to “0”, the above-described processing is executed, and the process returns to step S2.

Then, the answer at step S56 is affirmative (Ye
s), that is, when it is determined that the lens holding frame 13 has reached the inner wall of the lens barrel 2, the second flag F2 is set to “1” in step S65, and the power-off flag FOFF is set to “1” in step S66. And returns to step S2.

If it is determined in step S7 that there is no power-off request, the flow advances to step S67 to determine whether the first flag F1 is set to "1".
If the answer is negative (No), the process returns to step S2, while if the answer in step S67 is affirmative (Yes), the initial data I in the vertical direction is transmitted to the EVR 53 (step S68), and the process proceeds to step S69. Normal anti-shake control is performed, and in the following step S70, the first and second flags F1, F2 and the power-off flag FOFF are cleared to "0", and the process returns to step S2.

As described above, in the third embodiment, when there is a power-off request, the lens movement is controlled by the two predetermined values A and C, for the following reason.

That is, when the magnification of the zoom lens 5 is increased to 10 times or more, as in a recent image pickup apparatus, so-called "remaining shake" occurs when the resolution of the image pickup apparatus is not high during normal image stabilization control. Becomes noticeable. For this reason, if the resolution is set so as to improve the movement of the shift lens 7 in the range actually used, the lens holding frame can be changed no matter how the output from the drive amount control unit 31 is changed in the current imaging device. 13 may not be able to reach the inner wall of the lens barrel 2. Also, for the offset, EVR
If the operation resolution of the shift lens 7 for the data to be transmitted to 53 is not increased, even if the optical axis 4 is slightly displaced from the center axis of the imaging optical system in the high-magnification zoom lens 5, the center is displaced during the zoom operation. Becomes noticeable. Therefore, it is necessary to increase the operation resolution of the shift lens 7 assuming such a case.
No matter how the output is changed, the lens holding frame 13 may not move to the inner wall of the lens barrel 2 in some cases.

Therefore, in the third embodiment, the shift lens 7 at the time of the power-off request is set by the predetermined value A and the predetermined value C.
Is controlling.

Next, when the mode microcomputer 32 detects that the power switch 33 is turned off, the drive amount control unit 5
1 determines that there has been a power-off request, stores the initial data of the EVR 53 in the memory of the drive amount control unit 51, moves the shift lens 7 based on the initial data I, and then sets the set value C (= I−ΔD) , The 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. When the power is turned off, the shift lens 7 falls under its own weight and the lens holding frame 13 holding the shift lens 7 and the lens barrel 2
It is possible to avoid generating an unpleasant collision sound with the inner wall of the vehicle.

[0072]

As described above in detail, according to the present invention, even if the movable lens which has been in a floating state due to the image stabilization control is turned off, the movable lens falls by its own weight and falls between the movable lens and the inner wall of the lens barrel. Can avoid generating harsh collision sounds,
The quality of the product can be improved.

Further, by constantly monitoring the position of the movable lens, power consumption can be reduced.

[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 a block diagram showing details of a drive amount control unit.

FIG. 5 is a flowchart illustrating an embodiment of a method for controlling a lens position in the imaging apparatus according to the present invention.

FIG. 6 is a diagram showing a temporal change of a lens position of a shift lens when a power-off request is issued.

FIG. 7 is a block diagram of a second embodiment of the present invention.

FIG. 8 is a main part electric circuit diagram of the second embodiment.

FIG. 9 is a main part flowchart of the second embodiment.

FIG. 10 is a block diagram of a third embodiment of the present invention.

FIG. 11 is a main part flowchart of the third embodiment.

FIG. 12 is a diagram schematically showing a lens arrangement of a conventional imaging optical system.

FIG. 13 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. 14 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 9 image sensor (photoelectric conversion means) 10p, 10y voice coil motor (lens driving means) 31 drive amount control unit (drive amount control means, lens movement control means, stop means) 34 main microcomputer (judgment means) , Monitoring means) 42 Angular velocity sensor (vibration detecting means)

Claims (14)

[Claims] An imaging lens group including at least a movable lens that moves in a plane perpendicular to an optical axis; a shake detection unit that detects shake of an apparatus body; and a lens drive that electromagnetically floats the movable lens. Means, a drive amount control means for controlling a drive amount of the imaging lens drive means in accordance with a detection result of the shake detection means, and an image of the movable lens when the apparatus main body issues a stop request. An imaging apparatus comprising: lens movement control means for gradually bringing the movable lens closer to an inner wall of a lens barrel in which a lens group is provided. 2. A position fixing means for fixing the position of the movable lens to a plane center position in the lateral direction when it is judged by the judgment means that the apparatus main body issues a stop request. The imaging device according to claim 1, wherein: 3. The lens movement control means includes: first movement means for immediately moving the imaging lens in the vertical direction up to a position near an inner wall of the lens barrel; 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 vicinity of the inner wall. Claim 1
Or the imaging device according to claim 2. 4. An apparatus according to claim 1, further comprising: a position detecting unit for detecting a position of the movable lens; and an output adjusting unit for offset-adjusting a detection result of the position detecting unit. The imaging device according to claim 1, wherein the movement of the movable lens is controlled in accordance with the following. 5. An apparatus according to claim 1, further comprising: a position detecting unit configured to detect a position of the movable lens; and an output adjusting unit configured to adjust a detection result of the position detecting unit. First moving means for immediately moving the imaging lens in the vertical direction to near the inner wall, and lens holding for holding the movable lens after the movable lens reaches near the inner wall by the first moving means. Second moving means for gradually moving the movable lens to the inner wall side until a frame comes into contact with the inner wall, further comprising: a lens moving control means for controlling the movement of the movable lens in accordance with an adjustment result of the output adjusting means. The imaging apparatus according to claim 1, wherein the movement of the lens is controlled. 6. 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. 7. The apparatus according to claim 1, wherein the determination unit determines that the apparatus main body has issued a stop request when a power switch for driving the apparatus main body is switched from an on state to an off state. The imaging device according to claim 1. 8. A shake of the apparatus main body is detected, the movable lens is electromagnetically floated to move the movable lens in a plane perpendicular to an optical axis, and the movable lens is moved in accordance with the shake of the apparatus main body. In a method for controlling a lens position in an imaging apparatus that performs a drive amount control process for controlling a drive amount, when the apparatus main body issues a stop request, an inner wall of a lens barrel in which the movable lens is disposed is provided. A method of controlling a lens position in an imaging apparatus, wherein a lens moving process for gradually bringing the movable lens closer is performed. 9. The lens position according to claim 8, wherein the position of the movable lens is fixed to a plane center position in the lateral direction when the apparatus main body issues a stop request. Control method. 10. The movable lens is immediately moved in the longitudinal direction to a position near the inner wall of the lens barrel, and after the movable lens reaches a position near the inner wall, a lens holding frame for holding the movable lens is provided. The method according to claim 8, wherein the movable lens is gradually moved in the vertical direction until the movable lens contacts the inner wall. 11. The lens according to claim 8, wherein the position of the movable lens is detected, the detection result is offset-adjusted, and the movement of the movable lens is controlled based on the offset adjustment. Position control method. 12. The movable lens is immediately moved in the longitudinal direction to near the inner wall of the lens barrel, and after the movable lens reaches near the inner wall, a lens holding frame for holding the movable lens is provided on the inner wall. The movable lens is gradually moved in the vertical direction until the movable lens comes into contact with the movable lens, and the position of the movable lens is detected to detect the position and the detection result is offset-adjusted, and the movement of the movable lens is controlled based on the offset adjustment. The method for controlling a lens position in an imaging device according to claim 8, wherein 13. The apparatus main body is stopped after the movable lens is gradually approached to an inner wall of the lens barrel and a lens holding frame for holding the movable lens comes into contact with the inner wall. A method for controlling a lens position in the imaging device according to any one of claims 8 to 12. 14. 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.