JP2754872B2 - Image blur prevention device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image blur prevention device for preventing an image of an optical device from being shaken due to hand shake or the like.

(Background of the Invention) Conventionally, there has been known an optical apparatus having a function for preventing image shake caused by camera shake or the like.

For example, U.S. Pat.
Japanese Patent Application No. 829557 discloses an arrangement in which a correction optical system is movably arranged to prevent image blur due to its inertia.

FIG. 19 shows the overall configuration of this type of image blur prevention device. In FIG. 19, the image blur prevention device is fixed to a lens barrel (hereinafter simply referred to as a barrel) 4 for forming an image on a focal plane 14. The lenses 1 and 2 are correction optical systems for correcting image shake with respect to the main lenses 12 and 13 thus set. Focal length of the correction optical system is a focal length of the lens 1 having a negative optical power and being fixed to the lens barrel 4 and f _1, the focal length of the lens 2 having a positive power that are supported by the movable supporting member 3 Assuming that f ₂ , f ₁ is set so as to satisfy the relationship of f ₁ = −f ₂ .

The movable support member 3 is moved from the image-side principal point of the lens 2 to the focal length f ₂ by a gimbal 5 for supporting biaxial movement.
The lens barrel 4 is supported at the position (= −f ₁ ).

FIG. 20 shows the structure of the biaxial movable support of the gimbal 5. The movable support member 3 holding the lens 2 is supported by a support member 5y having a degree of freedom around the y-axis.
Is supported by a support member 5x having a degree of freedom about the x-axis perpendicular to the y-axis direction, and the support member 5x is supported by the lens barrel 4 to form a correction optical system having two-axis rotational degrees of freedom. doing.

In FIG. 19, reference numeral 10 denotes a counter weight as a balancer for balancing the movable support member 3, and the lens 2 of the movable support member 3 with the gimbal 5 interposed therebetween.
The lens 2 is attached to the gimbal 5
It is designed to balance with.

With the above configuration, a so-called inertial pendulum type anti-vibration optical system can be realized. That is, according to the configuration of FIG. 19, image blur is prevented as described below.

For example, assuming that the configuration shown in FIG. 19 is a telescope, an optical image of the target is focused on the focal plane 14 by the main lenses 12 and 13 and the correction optical systems 1 and 2 inside the lens barrel 4 directed to the target. Is imaged. In a telescope with a high magnification, when the camera is used by hand, vibration having a frequency component in the range of about 0.1 to 10 Hz is generated in the lens barrel 4 due to camera shake or the like, and image vibration occurs due to the vibration.

However, according to the optical mechanism, relative displacement occurs between the lens 2 and the lens 1 due to the inertia of the movable support member 3 due to the vibration, and the image is shaken due to the relative displacement between the lens 2 and the lens 1. Is to be suppressed.

In FIG. 19, a member 9 attached to the movable support member 3 is a non-magnetic conductor such as an aluminum piece, and a magnetic effect formed by the magnets 6 and 7 fixed to the lens barrel 4, A suppression force (damping force) corresponding to the vibration speed of the lens barrel 4 is generated. This is for generating a damping action for preventing the movable support member 3 from hitting the inner wall of the lens barrel 4 when, for example, the lens barrel 4 is rapidly displaced to change the composition. is there.

Specifically, the eddy current generated by the conductor 9 with respect to the magnets 6 and 7 whose enlarged views are shown in FIG. 21 is generated by the optical axis of the lens 2 and the optical axes of the main lenses 12 and 13 (main optical axis 15). A force is generated in a direction in which the amount of displacement of the movable support member 3 from the movable center position at which.

Although the magnets 6 and 7 are attached only to the upper part of the lens barrel 4 in FIG. 21, this is omitted for convenience of explanation, and the same magnets are provided at the lower part and right and left of the lens barrel 4. It is needless to say that the two-axis control is performed by providing

In FIG. 19, reference numeral 11 denotes a magnetic body integrally attached to the movable support member 3 and the counter weight 10, and a magnetic effect formed between the magnetic body 11 and the magnet 8 fixed to the lens barrel 4. As a result, a centering operation for returning the movable support member 3 to the movable center position where the optical axis of the lens 2 coincides with the main optical axis 15 is performed. In this centering operation, when there is no shake, using the center portion of the lens 2 has better optical characteristics. Therefore, a manufacturing error or a displacement corresponding to a DC component in a frequency component of the displacement is removed. The second optical axis is made to coincide with the main optical axis 15.

Specifically, as shown in an enlarged view of FIG. 21, the magnetic body 11 and the magnet 8 face the same magnetic pole (N poles) to each other, and are configured to magnetically repel each other. Have been. Since the center of the magnet 8 coincides with the main optical axis 15, a centripetal force (centering force) is generated so that the optical axis of the lens 2 coincides with the main optical axis 15.

With the above damping and centering configuration,
The prevention characteristics can be improved.

By the way, in the above-mentioned device, the correction optical system (movable support member 3) is in a state of being very easily moved with respect to the lens barrel 4.
Therefore, when a large impact is applied during transportation of the device (or a device in which the device is incorporated), the movable support member 3 hits the lens barrel 4 violently, and the movable support member 3 is deformed or prevented. The vibration performance will be degraded.

As a countermeasure, conventionally, when the apparatus is not used, the fixing means is operated using a motor or the like to fix the movable support member 3 at the movable center position.

However, the fixed position of the movable support member 3 fixed by the fixing means may change due to a temperature drift of a circuit for controlling the motor or an error of a component of the fixing means (due to a displacement or the like). If a relative displacement occurs between the fixed position and the position where the movable support member 3 is regulated by the vibration isolation control due to the above, the fixing by the fixing unit is released, and thereafter, When the anti-vibration operation is started, it is necessary to move the movable support member 3 from the fixed position to the restricted position in order to adjust the above-mentioned displacement. Also,
For example, if the above-described movement is performed in a state where the image whose vibration is prevented is used as a finder image, there is a disadvantage that the image is shifted at that time.

(Object of the Invention) The present invention has been made in view of the above-described circumstances, and describes a position at which a movable unit that operates for image blur prevention is fixed by a fixing unit and a reference at the time of the image blur prevention operation. It is an object of the present invention to provide an image blur prevention device capable of setting a proper relationship with a position.

(Features of the Invention) In order to achieve the above object, the present invention provides a movable means for preventing image blur, a fixing means for fixing the movable means,
An actuating means for operating the movable means, a position detecting means for detecting the position of the movable means, and fixed by the fixing means so that the movable means performs an image blur prevention operation around a predetermined reference position. The position of the movable unit when the movable unit is in the fixed state is detected by the position detection unit, and the position of the movable unit when the movable unit is fixed by the fixing unit is detected. And a control means for determining the reference position when the operating means causes the movable means to perform an image blur prevention operation.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIGS. 2 to 4 show the structure of an image blur prevention device according to the present invention, which is based on the same inertial pendulum system as the image blur prevention device of FIG.
The same parts as those in the drawings are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 2, the main imaging optical system includes a front lens 91, a variable power lens 92, and fixed lenses 93 and 94 for image formation. It is movably arranged for the purpose. The moving position of the variable power lens 92 can be detected by a variable power encoder (hereinafter referred to as ENC) 95, and the output of the ENC 95 can grasp the state of the focal length of the photographing optical system. In FIG. 2, the ENC95 exemplifies a 2-bit optical reflection type.

In FIGS. 2, 3 and 4 (sectional views taken along the line AA in FIG. 2), reference numeral 140 denotes a rotating member for temporarily fixing (locking) the movable support member 3 to the lens barrel 4, and a gear 140a. Having. 141a and 141b are pins for determining the lock position of the movable support member 3, and the tips of the pins are spherical screws.
a, 143b. Reference numeral 142 denotes a leaf spring for biasing the movable support member 3 to a position determined by the pins 141a and 141b. By rotating the pins 141a and 141b, the position of the movable support member 3 at the time of locking can be adjusted, and the optical performance at the time of locking can be improved. 144a and 144b are tension coil springs, which urge the rotating member 140 counterclockwise with respect to the lens barrel 4. In FIG. 3, the rotating member 140 contacts the stopper 4a, and the movable support member 3 is in a locked state. 145 is a motor for rotating the rotary member 140, 146 is a disk fixed to an output shaft 145a of the motor 145, and 147 is engaged with a gear 140a, and 147 is an output shaft 145a of the motor 145. A gear 148 is rotatably connected to the movable support member 3 by a limited angle, and a lock member 148 holds the rotary member 140 at the unlocked position of the movable support member 3.
9 is a leaf spring for urging the lock member 148, and 150 is a manual lock switch (ML) that is turned ON / OFF by the movement of the lock member 148 and generates a lock or unlock state signal.
SW) (ON when unlocked).

In FIG. 2, a sensor system (30, 31, 32) is arranged on the inner wall of the lens barrel 4 and the movable support member 3, and a torque generator system (41, 42, 43) is arranged on an axially symmetric portion thereof. . The x-axis and the y-axis have the same configuration, and are disposed at positions orthogonal to the x-axis and the y-axis.

FIG. 7 shows the configuration of the sensor system. This system includes a light emitting element 30 such as an LED mounted on the inner wall of the lens barrel 4, a power supply 34 for the light emitting element 30, a one-dimensional light receiving position detecting element 32 such as a PSD for receiving the light, and a movable support member 3. And the slit curtain 31 attached to the.

The slit curtain 31 provided between the light emitting element 30 and the one-dimensional light receiving position detecting element 32 moves in the direction of the arrow in the figure with the movement of the movable support member 3 holding the lens 2 as a correction optical system. A signal corresponding to the deflection angle from the detection element 32 is detected, and the signal is transmitted from the sensor amplifier 33 to the movable support member 3.
Is output as a displacement signal with respect to the lens barrel 4.

Next, FIG. 8 shows an example in which the configuration of the torque generator system is a voice coil type configuration. This system is a lens barrel 4
Voice coil 42 and movable support member 3 attached to the inner wall of the vehicle
And a magnet 41 attached to the

When a control signal is input to the input terminal 43, a magnetic coupling force (or a magnetic repulsion) is generated between the voice coil 42 and the magnet 41 in accordance with the current amount and the polarity, and the direction of the arrow in FIG. Torque can be generated.

As described above, the sensor system (30, 31, 32) and the torque generator system (41, 42) are arranged so that the x-axis and the y-axis are orthogonal to each other. The torque of the movable support member 3 can be controlled around the x-axis and the y-axis so as to dumb and center the movement of the movable support member 3.

FIG. 1 shows the input of the output of the sensor amplifier 33, the control of the driving of the voice coil 42 according to the displacement state of the movable support member 3 with respect to the lens barrel 4, the rotation of the movable support member 3 around the x-axis and the y-axis. FIG. 4 is a block diagram illustrating a control system for performing torque control for rotation.

In FIG. 1, a sensor amplifier 33 around the x-axis and around the y-axis of the movable support member 3 (in FIG. 1, a sensor system (here, 31, 3
2 includes 33, 34) are indicated by 30x, 31x, 32x, 33x, 34x, and the sensor system around the y axis is 30y, 31y, 32y, 33y,
The displacement signal from the movable support member 3 to the lens barrel 4 is indicated by a control circuit constituted by a microcomputer or the like.
The reference data (circuit) is converted from digital data by the A / D converter 511 in the reference data 50 and is output from the reference data holder 512 which holds the position signal (output of the sensor amplifier 33) of the movable support member 3 at the time of locking. The position at the time of locking of the movable support member 3 is shifted from the movable center position due to the temperature drift and the displacement of each member, that is, the difference from the displacement amount (the deflection angle θ) is not “0” is calculated by the adder 513. And output to the subsequent circuit.

The signal that has been A / D converted as described above and processed as described later is converted into analog data by the D / A converter 524 and output from the control circuit 50. Then, based on the analog data, drive circuits 53x, 53y drive the torque generator systems 41, 42 (in FIG. 1, x of the movable support member 3).
The drive around the axis is indicated by 41x and 42x, and the turn around the y-axis is indicated by 41y and 42y).

The basics of the anti-shake control by the control circuit 50 are anti-shake and
In order to satisfy two contradictory factors of preventing excessive movement of the lens unit related to panning and tilting, the torque generator systems 41x and 42x are used for the displacement of the movable support member 3 as the inertial pendulum with respect to the lens barrel 4. And a non-linear control torque for damping and centering is generated at 41y and 42y.

 FIG. 9 shows a characteristic example of the control torque.

According to the characteristic of the control torque shown in FIG.
Is located near the movable center, the torque generator systems 41x, 42x and 41x should be
y, 42y hardly generates torque for damping.

On the other hand, the lens barrel 4 is largely moved in a certain direction such as panning (moving the lens barrel 4 in the horizontal direction to change the composition) or tilting (moving the lens barrel 4 in the vertical direction to change the composition). In such a case, if the movable support member 3 is greatly displaced from the movable center by the action of the inertial pendulum,
As the displacement increases, the torque generator system 41x, 42x
Further, a suddenly increasing centering and damping force for returning the movable support member 3 to the movable center is generated at 41y and 42y to prevent the movable support member 3 from hitting the inner wall of the lens barrel 4.

When the torque curve of FIG. 9 is viewed from the direction of the main optical axis 15 of the pendulum, an image as shown in FIG. 10 is obtained. Since one concentric circle indicates a certain amount of torque change, the distance between the concentric circles becomes closer toward the outer periphery, that is, the end of the lens barrel 4, and the inclination of the torque characteristic becomes smaller as the movable support member 3 is displaced from the movable center. It turns out to be steep. That is, a state in which the torque increases in a non-linear curve referred to in FIG. 9 is shown.

By controlling the centering and damping torque in this way, the centering and damping action is largely performed when the movable support member 3 approaches the lens barrel 4 to prevent the movable support member 3 from hitting the inner wall of the lens barrel 4. In other cases, the centering and the damping action are minimized so as not to hinder the vibration damping action of the inertial pendulum.

In order to realize the control characteristics shown in FIG.
For example, coefficients K ₁ and K ₂ for obtaining the torque curve shown in FIG. 9 according to the displacement amount (deflection angle θ) of the movable support member 3 inputted from the sensor amplifiers 33x and 33y are stored in the memory in the control circuit 50. stored look-up table (hereinafter referred to as LUT) 516 and 517 and selected from the control function _{DATA = K 1 * θ + K} 2 * dθ / dt + K 3 * ∫θdt calculates the (where the coefficient K ₃ small constant value And * means multiplication), and this DATA is generated as a control torque in the torque generator systems 41x, 42x and 41y, 42y.

In the above control function, the term “K ₁ * θ” is shown in FIG.
LUT 516, synthesizer 519, and multiplier 521, which act as a spring term for generating a centering force according to the displacement amount from the movable center of movable support member 3,
The term “K ₂ * dθ / dt” is a damping term and is shown in FIG.
7, which is obtained by a differentiator 518, a combiner 520, and a multiplier 522, has an effect of suppressing sudden panning and tilting, and the “K ₃ * ∫θdt” term is for centering. This has the effect of canceling errors generated by various factors such as accumulation errors and manufacturing errors during mass production and returning the movable support member 3 to the movable center position. Such an integral action sets the degree of influence on the control system low, so that non-linear processing as in other terms is not performed.

Then, the respective terms are added by an adder 523 shown in FIG. 1 and converted again into analog data by a D / A converter 524 in the next stage, and the torque generator 42x is provided via drive circuits 53x and 53y. , 42y.

Further, the control circuit 50 controls the locking and unlocking of the movable support member 3 through the drive circuit 160 through the motor 1.
Perform by 45. FIG. 11 is a circuit diagram showing details of this part, and the driving circuit 160 includes diodes D1 to D5 and resistors R1 to
R4, a transistor Tr that is turned on when the power supply (Vcc) is lost, a small-capacity capacitor C used as a backup power supply when the power supply is lost, and a drive unit DR that controls the drive of the motor 145
It is composed of

Further, as will be described later, the control circuit 50 controls the movable support member 3 by the mechanical fixing means shown in FIG. 3 and FIG.
It also operates as an electric fixing means for locking and unlocking the lock.

In FIGS. 1 and 11, AS (Auto Stablizer) SW
Is a switch for selecting whether or not to activate the anti-vibration function.

The configuration in the frame indicated by dotted lines 51 and 52 in the control circuit 50 in FIG. 1 is the same except for the coefficient data in the LUTs 516 and 517, so one side (in the frame of the dotted line 52) is simplified. , Are not shown. Also, the portion from the reference data holder 512 to the adder 523 in the configuration in the frame of the dotted line 51 shows the processing contents of the control circuit 50 in hardware.

In this example, the method of applying the control torque according to the output of the variable magnification encoder (ENC95) is made stronger at the wide angle than at the telephoto. FIG. 12 illustrates this state. The control torque curve is changed from (c) to (b) as the focal length of the photographing optical system changes from the telephoto (long focal length) end to the wide-angle (short focal length) end. → As shown in (a), change is made so as to have nonlinear characteristics to which a stronger torque is given.

Therefore, in the control circuit 50, the coefficients K ₁ and K _{2 of the} control function corresponding to the deflection angle θ of the movable support member 3 for giving the torque curves (a) at the wide-angle end to the LUTs 516 and 517 are set at the telephoto end. Of the movable support member 3 to give the torque curve (c)
The control functions K ₁ and K ₂ are set in accordance with the following formulas. These coefficients are selected according to the swing angle θ of the movable support member 3, and ENC 9
According to the value of 5, the composite calculation is performed so as to obtain the torque curve as described above so as to obtain the coefficients K ₁ and K _{2 of the} control function.

This is because it is generally known that camera shake is more noticeable in handheld shooting at telephoto than in wide-angle shooting, so it is a measure against large movements such as panning, and it has a negative effect on the original purpose of image stabilization. A certain control torque is adapted to the use condition of the optical device, and the characteristics at the time of telephoto shooting are made weaker than those at the time of wide-angle shooting, so that the characteristics are suitable for the vibration reduction effect.

This makes it possible to reduce the size and weight of the entire image stabilizing optical system without deteriorating the image stabilizing characteristics near the telephoto end.

 This will be explained a little below.

In FIG. 13, I and II denote a first lens group and a second lens group, respectively, of a correction optical system similar to lenses 1 and 2 in FIG.
Is a main imaging system. IV and V represent off-axis rays, respectively.

(A) is when the amount of vibration of the second group for vibration isolation is large,
(B) is when the amount of shake is small.

The size of each lens of the first lens group and the second lens group of the image stabilizing optical system is determined by the height at which the off-axis rays IV and V pass through the lens system.

Therefore, as shown in FIG. 13, when the shake angle is small, the height passing through the off-axis light beam is smaller than when the shake angle is large, so that the size of the optical system can be reduced.

Off-axis rays that determine the size of the optical system are usually rays that form an image at the maximum image height in the zoom range at or near the wide-angle end.

To reduce the angle of view near the telephoto end, it is necessary to secure a light beam with a certain shake angle near the wide-angle end (because the image shake is less noticeable at the wide-angle end than at the telephoto end), sufficient image stabilization Range can be obtained.

Therefore, if the swing angle, that is, the control range at the time of image stabilization near the wide-angle end is made smaller than the telephoto end by the torque characteristics as shown in FIG. 12, the image stabilization near the telephoto end is not impaired. It is possible to reduce the size and weight of the entire optical system (FIGS. 13A to 13B).

In the LUTs 516 and 517 in the control circuit 50, a control coefficient for performing torque control as shown in FIG. 12D and electrically locking the movable support member 3 at the movable center position is set. The operation (hereinafter referred to as an electric lock operation) is performed prior to operating the mechanical fixing means shown in FIGS. 3 and 4.

Next, the operation of the control system shown in FIG. 1 will be described with reference to the flowchart of FIG. 14. As an initial state, the switch ASSW is OFF, and the movable support member 3 is moved to the mechanical position as shown in FIG. It is assumed that it is locked by the target fixing means.

"Step 1" It is determined whether or not the switch ASSW has been turned on, and the process proceeds to step 2 by confirming that the switch has been turned on.

[Step 2] The position information of the movable support member 3 in the locked state is fetched from the output of the sensor amplifier 33, and this is held in the reference data holder 512.

[Step 3] An unlock operation is performed.

The details of the lock release operation will be described with reference to the flowchart of FIG.

"Step 3-1" A control function for obtaining a control torque curve as shown in (d) of FIG. 12 is read from the locking table in the LUTs 516 and 517, and the control torque data obtained by this is converted into a D / A. The data is converted into analog data by the device 524, and the converted data is output to the drive circuits 53x and 53y as deflection angle data (torque control signal), and an electric lock operation for positioning the movable support member 3 at the movable center is performed.

The reason why the electric lock operation is performed is to prevent the movable support member 3 from largely moving due to the shock released by the mechanical fixing means in the subsequent steps.

"Step 3-2" The motor 145 is rotated clockwise via the drive circuit 160.

When the motor 145 is driven clockwise in this manner, the rotating member 140 is rotated while extending the coil springs 144a and 144b clockwise from the state shown in FIG. 3 to unlock the movable support member 3. You. Thereafter, the switch 150 is turned on at the same time when the claw portion 148a of the lock member 148 enters the concave portion 140b of the rotating member 140, and the unlocking operation performed by the mechanical fixing means is completed (the state of FIG. 4).

"Step 3-3" Here, it is determined from the state of the switch 150 whether or not the unlocking operation performed by the mechanical fixing means has been completed. As mentioned earlier, switch 150
When it is turned on, the process proceeds to step 3-4.

[Step 3-4] The driving of the motor 145 is stopped.

"Step 3-5" The electric lock operation is stopped.

By ending the above operation, the process returns to the main routine of FIG. 14, and the operation from step 4 is started.

[Step 4] Since the switch ASSW is ON, the image stabilization control is started.

Details of the anti-shake control will be described with reference to the flowchart of FIG.

"Step 4-1" The value of ENC95 (ENC data) is taken in for detecting the focal length.

"Step 4-2" The mode i is designated as x for the process of calculating the control torque signal of the movable support member 3 around the x axis.

"Step 4-3" Set LUT selection mode j = 1,
Select which LUT that stores the coefficients of the above control function is used.

[Step 4-4] The output of the sensor amplifier 33x corresponding to the swing angle θ of the movable support member 3 about the x-axis (hereinafter referred to as θx) is taken in as digital data from the A / D converter 511.

"Step 4-5" The adder 513 subtracts the reference data, which is the position information of the movable support member 3 at the time of locking, held in step 2 from the fetched digital data, and outputs the result to the next stage.

Here, such calculation is performed by the movable support member 3.
The position at the time of locking and anti-vibration control are performed and the movable support member 3
If the position is shifted when the position is controlled to the movable center, a position shift of the image at the time of locking and unlocking occurs,
It would be unsightly, but to prevent this. More specifically, for example, assuming that the apparatus is incorporated in a camera, when pursuing a fast-moving subject, a sufficient anti-shake effect cannot be obtained by anti-shake control, so it is used in a locked state. The above-described problem occurs in the case where the mode shifts to the shooting in which the image stabilization control is performed again thereafter, but by using the position at the time of locking by the mechanical fixing unit as a reference as in the present embodiment, Such a problem can be solved.

"Step 4-6" With the setting of the LUT selection mode j = 1 in step 4-3, the control torque curve at the wide angle end as shown in FIG. and LUT-1x-W and LUT-1x was memory coefficient K ₁ of said control function obtained by the control torque during the telephoto end (c)
The coefficients K _1W and K _1T corresponding to the above-mentioned deflection angle θx are read from −T.

The coefficient K ₁ of said control function for the current focal length "Step 4-7", described above for the coefficients K _1W and K _1T described above
It is obtained by a combination operation according to the value of ENC95.

FIG. 18 shows an example of this combining operation in terms of hardware.

In FIG. 18, a synthesizer 519 (similarly to the synthesizer 520) includes a coefficient generator 81 for generating a coefficient 1 according to the resolution of the ENC 95, an arithmetic unit 82 for generating the one's complement (1-1), and "K _1T
* 1 ”and“ K _1W * (1-1) ”
When a 83, and outputs the coefficient K ₁ corresponding to the focal length by an adder 85 for adding computing an output of the multiplier.

Note that it is also possible to prepare the same number of LUTs as the number of steps (resolution) of the ENC corresponding to the output of the ENC 95, and omit this synthesizer.

"Step 4-8" It is confirmed whether or not the processing has been completed with respect to the setting of the LUT selection mode j of 1 or 2. If not completed (j = 2), the process proceeds to step 4-9.

"Step 4-9" Here, the LUT selection mode j = 2 is set again, and the process returns to step 4-6. According to the setting of the LUT selection mode j = 2, the twelfth is set with respect to the x-axis of the movable support member 3. the control function K ₂ obtained was the memory of the wide-angle end when the control torque curve as shown in FIG. (a) control torque curve at and the telephoto end (c) LUT-2x-W and LUT-2x
It reads the coefficient K _2W and K _2T from -T corresponds to the above-described [theta] x, obtaining the coefficient K ₂ of said control function by the above-described combining operation at step 4-7.

[Step 4-10] The above-described θx is differentiated (dθx / dt) to obtain data Δ.

"Step 4-11" this was multiplied by a coefficient K ₃ to the aforementioned θx integrating (∫θxdt), the data d1.

The factor K ₃ is a constant small value in order to set a lower influence on the control system as described above, other coefficients K _1, K ₂
Is not performed.

"Step 4-12" was multiplied by a coefficient K ₁ the previously obtained in the aforementioned [theta] x, is the same as the data d2.

“Step 4-13” The coefficient previously obtained from the above data Δ
Multiplied by the K _2, to do this with the data d3.

"Step 4-14" The data d1, d2, and d3 are added, and this is temporarily stored as "DATA".

That is, in this DATA = d1 + d2 + d3 = K 1 * θx + K 2 * dθx / dt + K 3 * calculation result of the control function by ∫θxdt is obtained.

[Step 4-15] It is determined whether the current processing mode i is related to the movable support member 3 around the x-axis.

If it is an odd number, it is about the x-axis (in the case of NO), and it proceeds to step 4-16. If it is an even number, it is about y (in the case of YES), and it proceeds to step 4-18.

"Step 4-16" The calculation result "DATA" is stored in Dx as control torque data about the x axis.

"Step 4-17" The processing mode i is changed to y, and the process returns to step 4-3. Next, the processing for calculating the control torque signal of the movable support member 3 around the y-axis is the same as the processing around the x-axis. Do the same.

However, in this case, in step 4-6, the control torque curve at the wide angle end (a) and the control torque curve at the telephoto end (c) as shown in FIG. LU that memory coefficient K ₁ of said control function obtained with
The coefficients K _1W and K _1T corresponding to the deflection angle θ (hereinafter referred to as θy) of the movable support member 3 around the y-axis are read out from T-1y-W and LUT-1y-T, and as shown in FIG. shake a coefficient K ₂ of said control function capable of obtaining a wide-angle end when the control torque curve (a) control torque curve at and the telephoto end (c) from LUT-1y-W and LUT-1y-T and memory described above Angle θy
_Is read out as the coefficient K _1W and the coefficient K _1T corresponding to.

"Step 4-18" The calculation result "DATA" is stored in Dy as control torque data around the y-axis.

[Step 4-19] The control torque data Dx and Dy are converted into analog data by the D / A converter 524 and output to the drive circuits 53x and 53y as torque control signals. Is performed.

In this manner, as the movable support member 3 approaches the inner wall of the lens barrel 4 by panning, tilting, or the like, according to the torque curve of the control function that gives a stronger torque as the focal length moves from the telephoto side to the wide-angle side, x The torque generator system (41x, 42x) around the axis and the torque generator system (41y, 42y) around the y-axis generate nonlinearly increasing torque for returning the movable support member 3 to the movable center position. The movable support member 3 is effectively returned toward the movable center.

Upon completion of the above operation, the process returns to the main routine of FIG. 14, and proceeds to step 5.

"Step 5" It is determined whether or not the switch ASSW has been turned off, and the process proceeds to step 6 by confirming that it has been turned off.

"Step 6" Here, the locking operation is performed.

The details of this locking operation will be described with reference to the flowchart of FIG.

"Step 6-1" A control function for obtaining a control torque curve as shown in (d) of FIG. 12 is read from the locking table in the LUTs 516 and 517, and the electric lock is obtained based on the control torque data obtained thereby. Perform the operation.

Here, the reason for performing the electric lock operation is to ensure that the lock by the mechanical fixing means is performed smoothly in the subsequent steps. That is, the movable support member 3
This is because if the locking operation by the mechanical fixing means is started in a state having a certain deflection angle, a large shock may be generated in the movable support member 3.

"Step 6-2" The motor 145 is rotated counterclockwise via the drive circuit 160 to start the locking operation by the mechanical fixing means.

The operation at this time is performed using FIG. 5 and FIG. FIG. 5 is an enlarged view of the vicinity of the motor 145 in FIG. 4, and FIG. 6 is a view seen from the direction B in FIG.

When the motor 145 is driven counterclockwise as described above,
Since the convex portion 145b provided on the output shaft 145a is fitted into the groove 147a provided on the gear 147, the gear 147 also rotates counterclockwise, but the grooves 147a and 145b have As shown, there is a gap corresponding to the angle θ, and only the output shaft 145a can rotate counterclockwise by θ from the state shown in FIG. 4 (unlocked state). By this rotation, the disk 146 fixed to the output shaft 145a rotates, and the protrusion 146a
48 is raised, and the pawl portion 148a is
Then, the rotating member 140 rotates until it comes into contact with the stopper 4a in accordance with the urging of the coil springs 144a and 144b, and then comes into a locked state as shown in FIG.

"Step 6-3""N" is substituted for the timer Vt. Note that this “N” indicates that the output shaft 145a of the motor 145 rotates counterclockwise by θ, the projection 146a of the rotating disk 146 flips up the lock member 148, and the pawl 148a This is a sufficient time required to separate from the groove 140b.

[Step 6-4 Decrease the value of the timer Vt by "1".

"Step 6-5" Here, it is determined whether or not the value of the timer Vt has reached "0". When it is confirmed that the value has reached "0", the process proceeds to step 6-6.

"Step 6-6" The action of the motor 145 is stopped.

"Step 6-7" The electric lock operation is released.

By ending the above operation, the process returns to the main routine of FIG. 14, and returns to step 1.

Incidentally, the movable support member 3 is locked by the control circuit 50.
However, in an actual use state, the following situation is considered in which the power is lost when the switch ASSW is turned on (when the lock is released).

The power switch is suddenly turned off.

The power supply voltage drops below the circuit operation guarantee voltage.

The battery that is the power supply comes off (intentional or negligent).

In such a case, the control circuit 50 needs to drive the motor 145 counterclockwise to stop the function and lock the movable support member 3 without depending on the control circuit 50.

The drive circuit 160 shown in detail in FIG. 11 also has a function to cope with this case. When the power is lost due to any of the above, the transistor Tr turns on and the input 1 (in1) of the drive unit DR goes high. Level, and the motor 145 is driven counterclockwise until the capacitor C is completely discharged. Therefore, as described above, the lock member 148 is flipped up, and the movable support member 3 is securely locked by the urging of the coil springs 144a and 144b.

According to the present embodiment, since the image stabilization control is performed based on the position information of the movable support member 3 at the time of locking, for example, when it is assumed that the device is incorporated in a camera, the motion is fast. In the case of the subject, use it in the locked state,
When the subject stops after that, even if the image is subjected to image stabilization control again, the image is not shifted between the locked state and the unlocked state, and the screen quality can be maintained.

(Correspondence between the Invention and the Embodiment) In the above embodiment, the lens 2 of the correction optical system is used as the movable means of the present invention, and the stopper 4a, the rotating member 140, and the tension coil springs 144a and 144b are used as the fixing means of the present invention, and the circuit 51 is used. , 52,
The drive circuits 53x and 53y and the voice coils 42x and 42y correspond to the operating means of the present invention, and the one-dimensional light receiving position detecting elements 32x and 32y correspond to the position detecting means of the present invention. Step 2 in FIG. 14 and step 4 in FIG. The reference data holder 512 and the adder 513 that perform -5 correspond to the control means of the present invention, respectively.

(Effects of the Invention) As described above, according to the present invention, according to the position when the movable unit that operates for preventing image blur is fixed by the fixing unit, the operation during the image blur prevention operation is performed. Since the reference position is determined, an appropriate relationship can be established between the position at which the movable unit is fixed by the fixing unit and the reference position at the time of the image blur prevention operation.

[Brief description of the drawings]

FIG. 1 is a diagram showing a control system of an image shake preventing apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view thereof, FIGS. 3 to 4 are sectional views of FIG. 4 is an enlarged view showing the vicinity of the motor shown in FIG. 4, FIG. 6 is a view seen from the direction B in FIG. 5, FIG. 7 is a perspective view showing a specific configuration example of the sensor system shown in FIG. 8 is a perspective view showing a specific configuration example of a torque generator system shown in FIG. 2, FIG. 9 is a control torque characteristic diagram which is a basic control system of FIG. 1, and FIG. 10 is a control diagram of FIG. FIG. 11 is an image diagram when torque is viewed from the main optical axis side.
FIG. 12 is a circuit diagram showing details of the drive system of the motor. FIG. 12 is a control torque characteristic diagram when the characteristics of the control torque are varied according to the focal length in this embodiment. FIG. 13 is an embodiment of FIG. FIGS. 14 to 17 are flow charts showing the operation of an embodiment of the present invention, and FIG. 18 is a specific diagram of the combiner shown in FIG. 1. FIG. 19 is a cross-sectional view showing the structure of a conventional image blur prevention device, FIG. 20 is a partially enlarged view for explaining the structure of the gimbal support in FIG. 19, and FIG. FIG. 20 is a partially enlarged view of the configuration in FIG. 19. 1,2 correction optical system, 3 movable support member, 4 lens barrel, 5 gimbal, 30 light emitting element, 31, 35
Slit curtain, 32: Light receiving position detecting element, 33: Sensor amplifier, 41: Magnet, 42: Voice coil, 50:
Control circuit, 140: rotating member, 141a, 141b: screw, 142
... leaf springs, 143a, 143b ... springs, 144a, 144b ... coil springs, 145 ... motors, 148 ... locking members, 149 ... leaf springs, 512 ... reference data holders, 513 ... adders.

Claims (1)

(57) [Claims] 1. A movable means for preventing image blur, a fixing means for fixing the movable means, and operating the movable means so that the movable means performs an image blur prevention operation around a predetermined reference position. Operating means for causing the movable means to detect the position of the movable means; and detecting the position of the movable means when the movable means is fixed by the fixing means. Determining the reference position at which the operating means causes the movable means to perform an image blur prevention operation according to the position of the movable means when it is fixed by the fixing means, detected by the means. An image blur prevention device comprising a control unit.