JPH05196897A - Image movement correcting device - Google Patents

Abstract

PURPOSE:To effectively utilize the limited correctable deflection angle of a correcting means, and to visually increase deflection prevention effect and improve the operability and the quality of an image by providing an image blur correcting means so that different deflection prevention characteristics are obtained horizontally and vertically, and applying torque to the correcting means in the tilt direction of the line connecting the movement center position of the correcting means and a current position. CONSTITUTION:A sensor part and a torque generation part are arranged on the internal wall of a lens barrel 4 and at the axially symmetrical part of a support member 3. An X shaft and a Y axis are of similar constitution and positioned and arranged crossing each other. The torque generation part generates a magnetic coupling force between a voice coil 42 and a magnet 41 corresponding to the current quantity and polarity of a control signal inputted to a control input terminal 43 to generate the torque as shown by an arrow. The sensor part and torque generation part are arranged so that the X shaft and Y shaft cross each other at right angles; and torque control is performed in all directions so as to damp the movement of a correction optical system associatively with gimbals supporting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image shake correcting device for correcting shake of an image of an optical device due to point shake or the like.

[0002]

2. Description of the Related Art As an image device having a function of correcting image blur due to camera shake or the like, a correction optical system as disclosed in, for example, US Pat. Nos. 2,959,088 and 28,295,57. Is movably disposed, and the image blur caused by camera shake is corrected by its inertia.

FIG. 14 is a schematic diagram showing the overall construction of the above-mentioned conventional apparatus. In FIG. 14, lenses 1 and 2 are correction optical systems for the lenses 12 and 13 of the main optical system. The focal lengths of the correction optical systems 1 and 2 are set as follows. The focal length of the lens 1 having a negative optical power and being fixed to the lens barrel 4 and f _1, and the focal length of the lens 2 having a positive power that are supported by the support member 3 of the movable and f _2, f The focal length of each lens is set so as to satisfy the relationship of ₁ = -f ₂ .

A gimbal 5 serving as an image shake correcting means for supporting biaxial movement supports the lens 2 at a focal length f ₂ (= -f ₁ ) from the image-side principal point of the lens 2. There is.

A counterweight 10 is provided to balance the correction optical system.

By satisfying such optical conditions, a so-called inertial pendulum type anti-vibration optical system can be realized.

Next, the biaxial movement of the gimbal 5 is shown in FIG.
Will be described.

The lens 2 is supported by a supporting member 5y having a degree of freedom in the y-axis direction, and this supporting member 5y is supported by a supporting member 5x having a degree of freedom in the x-axis direction perpendicular to the y-axis direction. The support member 5x is supported by the lens barrel 4, and a correction optical system having biaxial degrees of freedom can be configured.

Next, operations of centering (centering) and damping (vibration suppression) by various members attached to the support member 3 will be described with reference to FIGS. 14 and 16.

The non-magnetic material 9 such as an aluminum piece attached to the support member 3 is a suppression force corresponding to the speed due to the magnetic effect formed by the magnets (magnetic materials) 6 and 7 fixed to the lens barrel 4. (Damping force) is generated. Specifically, the overcurrent generated by the magnets 6 and 7 and the non-magnetic body 9 generates a force in a direction to reduce the amount of deviation from the center of the optical axis of the correction optical system, and produces a damping effect.

Although the magnets 6 and 7 are attached only to the upper portion of the lens barrel in FIG. 16, this is omitted for convenience of description, and the lower and left and right magnets are not shown in the drawing. It is necessary for axis control.

Numeral 10 is a counter weight, which serves as a balancer for supporting the pendulum at the focal position of the correction optical system and keeping balance in a normal stable state. It is attached to the other side.

Reference numeral 11 denotes a support member 3 and a counterweight 1
0 is a magnetic body integrally attached to the lens barrel 0, and performs centering operation by a magnetic effect formed between the magnet 8 and the magnet 8 fixed to the lens barrel 4.

The magnetic poles according to this structure have the same poles (N) facing each other and are magnetically repulsed. Therefore, the center of the magnet 8 is the lens 12 of the main optical system,
Since it coincides with the optical axis (main optical axis) 15 of 13, a centripetal force (centering / focus) is generated in the vicinity of the center so that the optical axes of the lenses 1 and 2 of the correction optical system coincide with the main optical axis 15. To do. Then, the lenses 12 and 13 form an image on the final focal plane 14.

Next, the overall operation will be described.

Taking the operation of the above-described vibration isolation system in an optical device such as a telescope as an example, inside the lens barrel 4 directed to the target object, the main optical system and the correction optical system cause
An optical image of the target is formed on the focal plane 14.

In a telescope having a high magnifying power, when used in a hand-held manner, in particular, an image blur occurs due to camera shake or the like, and a vibration having a frequency component in the range of 0.1 to 10 Hz occurs in the lens barrel 4. .. Due to this vibration, a relative displacement occurs between the lens barrel 4 and the lens 1 and the lens 2, and the image blur is corrected by this relative displacement.

In such a situation, when a sudden displacement occurs, the displacement is suppressed by the damping structure described above.

Further, when there is no blur, it is preferable to use the central portion of the lens 2 because the optical characteristics are better, so that the deviation corresponding to the DC component due to the manufacturing error or the frequency component of the above deviation is removed. In the vicinity of the center, the centering force is used so that the optical axis of the correction optical system and the optical axis of the main optical system coincide with each other.

As described above, when the image shakes, the image can be shaken by the pendulum type correction optical system, and the magnetic effect is used to add the centering and the dumbing.
Improves anti-vibration properties.

[0021]

However, it is often necessary to perform operations such as panning and tilting in order to track or change the subject during actual photographing. On the other hand, in the above-mentioned conventional example, the system has only the vibration isolation operation, and has the vibration isolation effect with respect to vibration such as camera shake, but with regard to the behavior during the realistic pan / tilt operation that continuously moves in one direction. Has a problem in that the image stabilization effect is reduced, the correction optical system is largely moved in one direction, and it collides with the inner wall of the lens barrel, resulting in an unnatural image movement.

An object of the present invention is to provide an image blur correction device that solves the above problems.

[0023]

The present invention is an image blur correction device having the following configuration. (1) A support member that supports the movable lens, an image shake correction unit that supports the support member on the lens barrel with different image stabilization characteristics in the horizontal direction and the vertical direction, the movable center position of the image shake correction unit, and the current position. By providing the torque generating means for applying a torque to the support member in the inclination direction of the line connecting the position, the limited correctable shake angle of the correction optical system can be effectively used, and the visual vibration isolation effect can be obtained. It became possible to realize an extremely high vibration isolation system. (2) A support member that supports the movable lens, an image shake correction unit that supports the support member on the lens barrel with different image stabilization characteristics in the horizontal direction and the vertical direction, and the movable center position of the image shake correction unit and the current position. The torque generating means for applying a torque to the supporting member in the inclination direction of the line connecting the position, the torque generating means is composed of a coil for passing a constant current and a magnet having a non-linear magnetizing curve. By generating a restoring force to the optical neutral point of the support means,
It is possible to obtain natural image movement.

[0024]

Embodiments of the present invention will now be described with reference to the drawings. According to the first aspect of the present invention, there is provided torque generating means for controlling the movement of the correction optical system to prevent the lens barrel from colliding against the inner wall, which is likely to occur due to operations such as pan and tilt, and a control signal for controlling the torque generating means. The generator and a sensor for detecting the movement of the correction optical system as an input signal of the arithmetic processing for generating the control signal are the main constituent elements.

From the above control signal generator, in order to satisfy the two basic functions of anti-vibration and prevention of excessive movement of the lens portion related to panning, as shown in FIG. Thus, a non-linear control torque is given.

In the vicinity of the center of the movement of the correction optical system, almost no torque is applied for damping in order not to hinder the movement of the inertial pendulum for image stabilization.

However, when a large movement in one direction is applied as in panning or the like, a large torque that pulls back to the center is generated so that the inertial pendulum lens portion does not hit the inner wall of the lens barrel. Is configured.

Next, the structure of this embodiment will be described. FIG. 2 is a view best showing the features of the present invention.
The same parts as those of the conventional device shown in FIG.

A sensor portion S and a torque generating portion T are arranged on the inner wall of the lens barrel 4 and the axially symmetrical portion of the support member 3. The x-axis and the y-axis have the same configuration, and the x-axis and the y-axis are the same.
It is arranged at a position orthogonal to the axis.

FIG. 3 shows the structure of the sensor section S. The sensor section S is an optical element 30 such as an LED mounted on the inner wall of the lens barrel 4, and a power source 34 connected to the light emitting element 30. And a one-dimensional image sensor 32 such as a PSD for receiving the light of the light emitting element 30, and a slit curtain 31 attached to the support member 3.

Light emitting element 30 and one-dimensional image sensor 32
Since the slit curtain 31 provided between the two moves in the direction of the arrow in the figure with the movement of the support member 3 of the correction optical system, a signal corresponding to the deflection angle can be detected from the one-dimensional image sensor 32.
A position signal of the correction optical system is obtained from the sensor amplifier 33.

FIG. 4 shows an example in which the torque generating section T is constituted by, for example, a voice coil type.
A magnetic coupling force (or a magnetic repulsion force) is generated between the voice coil 42 and the magnet 41 in accordance with the current amount and the polarity of the control signal input to, and torque is generated in the arrow direction.

As described above, the sensor section S and the torque generating section T are arranged so that the x axis and the y axis are orthogonal to each other, and in combination with the gimbal support, torque control can be performed in all directions in order to dampen the movement of the correction optical system. I can.

FIG. 5 shows an example in which a control system for controlling the image stabilization, panning, and tilting having the above-mentioned configuration is constituted by a microcomputer. The sensor section S and the torque generating section in the Y-axis (X-axis) direction are shown. T is a slit plate 3 which is integrated with the support member 3 for each movement.
1Y, 31X, light emitters 30Y, 30X connected to power sources 34Y, 34X, and a sensor 32 disposed opposite to the light emitters 30Y, 30X with the slit plates 31Y, 31X interposed therebetween.
Y and 32X, amplifiers 33Y and 33X for amplifying the output signals of the sensors 32Y and 32X and supplying the same to the microcomputer 50 as a control circuit, and receiving the output signals of the microcomputer 50 to excite the coils 42Y and 42X and A driver 53 that applies torque to the passive portions 41Y and 41X of the support member 3.
It is composed of Y and 53X.

In FIG. 5, the sensor section S, the torque generating section T, and the torque generating section T are provided on the x-axis and the y-axis, respectively. The letters X and Y are attached. ).

Further, the microcomputer 50 uses the amplifier 33.
A / D converters 501 and 510 for converting analog signals from Y and 33X into digital signals, and A / D converter 501
Circuit 502 that integrates the output signal of the A / D converter 501, a differentiation circuit 505 that differentiates the output signal of the A / D converter 501, and an A / D
A multiplication circuit 507 that multiplies the output signal of the converter 501 and the constant A that is the output signal of the setting device 506, and the output signals of the multiplication circuit 507 and the A / D converter 510 are input, and the root mean square is calculated. First look-up table (hereinafter LU
T) 503 and a second look-up table (hereinafter referred to as LUT) 504 to supply the mean square circuit 508.
A multiplication circuit 513 for multiplying the output signal of the first LUT 503 by the multiplication circuit 507, and the differentiation circuit 505.
And a multiplication circuit 514 that multiplies the output signal of the second LUT 504, and an addition circuit 515 that adds the output signals of the multiplication circuits 513 and 514 and the output signal of the integration circuit 502.
An integrating circuit 511 for integrating the output signal of the A / D converter 510, a differentiating circuit 512 for differentiating the output signal of the A / D converter 510, an output signal of the differentiating circuit 512 and an output of the second LUT 504. Multiplier circuit 5 that multiplies signals
16, the output signal of the A / D converter 510 and the first signal
A multiplication circuit 517 for multiplying the output signal of the LUT 503,
An adding circuit 518 for adding the output signals of the integrating circuit 511 and the multiplying circuits 516, 517; and the adding circuit 51.
A matrix conversion circuit 519 for inputting output signals of 5, 518, and D / A converters 509, 52 for converting the digital signals output from the matrix conversion circuit 519 into analog signals and supplying the analog signals to the drivers 53Y, 53X.
It is composed of 0 and.

The signal from the sensor section S is converted into a digital signal by the A / D converters 501 and 510 in the microcomputer 50 indicated by the dotted line, and processed in the microcomputer 50 as deflection angle data.

The processing result by the microcomputer 50 is D
After being converted into analog data by the A / A converters 509 and 520, the data is supplied to the coils 42X and 42Y, which are components of the torque generator T, via the drivers 53x and 53y.

FIG. 6 is a flow chart showing the processing procedure by the microcomputer 50. Next, the meaning of the torque generated by the series of processing procedures will be described.

The first LUT 503 and the second LUT 504 have a displacement from the center of the pendulum, that is, the A / D converter 5.
Values corresponding to the outputs θ _x and θ _y of 01 and 510 are set.

[0041]

[Equation 1] That is, the output of the first LUT 503 = B * (A ² θ _x ² +
θ _y ² ) ^{N / 2} (B and N are constants) Output of second LUT 504 = C * (A ² θ _x ² + θ _y ² ) ^{M / 2}
(C and M are constants).

The outputs of the multipliers 513 and 517 represented by the product of the output of the first LUT 503 are represented by the following equations.

Output of multiplier 513 = A * θ _x * B * (A ²
θ _x ² + θ _y ² ) ^{N / 2} multiplier 517 output = θ _Y * B * (A ² θ _x ² + θ _y ² ) ^{N / 2} These outputs are outputs according to the displacement, and Taking the root mean square,

[0044]

[Equation 2] = B * (A ² θ _x ² + θ _y ² ) ^{(N + 1) / 2} , and A ² θ _x ² + θ _y ² = (constant), then = (constant).

This means the following. As shown in FIG. 7, A ² * θ _x ² + in the θ _x and θ _y planes
θ _y ² = (constant), that is, all points on the elliptic curve output the same torque. Accordingly, by performing these calculations with one first LUT 503, it is possible to obtain an effect equivalent to changing the vibration isolation characteristics in the X-axis direction and the Y-axis direction.

Similarly, the outputs of the multipliers 514 and 516 represented by the product of the output of the second LUT 504 are represented by the following equations.

Multiplier 514 = (dθ _X / dt) * C *
(A ² * θ _x ² + θ _y ² ) ^{M / 2} multiplier 516 = (dθ _Y / dt) * C * (A ² * θ _x ² +
θ _y ² ) ^{M / 2} These outputs are outputs depending on the speed. Taking the root mean square of these outputs,

[0048]

[Equation 3] Then, = (constant).

This means the following. The points on the elliptic curve shown in FIG. 7 indicate that the same torque is output for all constant speeds. This makes 1
By performing these calculations using the two second LUTs 504, it is possible to obtain an effect equivalent to changing the vibration isolation characteristics in the X-axis direction and the Y-axis direction.

Then, the combined force of the output of the adder 515 and the output of the adder 518 is converted by the matrix converter 519 so that the combined force always faces the center.

More specifically, as shown in FIG.
The output of the adder 515 is T _x , and the output of the adder 518 is T _y
Then, it is assumed that the combined torque T does not face the center. At this time, in order for the combined torque to point toward the center,
As shown in FIG. 8, the matrix converter 519 obtains outputs T _x ′ and T _y ′ after being rotated by the deviation angle α from the center and then decomposed into θ _x and θ _y axes.

By the series of steps ST1 to ST12 described above, the vibration isolation characteristics in the horizontal and vertical directions can be changed, and at this time, the direction of the torque applied to the pendulum can always be directed to the center. It is possible to obtain high-quality panning characteristics.

Embodiment 2 FIG. 9 shows an embodiment of the invention described in claim 2. The same parts as those of the first embodiment shown in FIG.

In FIG. 9, the main image pickup optical system includes a front lens 91, a variable power lens 92, and fixed lenses 93 and 94 for image formation.
The variable power lens 92 is movably arranged by a movable moving ring 96 for changing the focal length. The position of the variable power lens 92 can be detected by a variable power encoder (hereinafter referred to as ENC) 95.
The output of 95 makes it possible to know where it is located between T and W. Incidentally, ENC95 exemplifies a 2-bit optical reflection type.

A magnet 41, a coil 42, and a control input terminal 43, which are constituent members of the torque generator T, are arranged on the lens barrel 4 and the support member 3.

FIG. 10 is an exploded perspective view showing the structure of the torque generator T, and the magnet 41 is magnetized in the direction of the arrow in the figure. The coil 42 has a winding direction in the direction of the arrow in the drawing, and when a positive voltage is applied to one terminal 431 of the control input terminal 43 and the other terminal 432 is grounded, a current flows in the winding direction in the drawing. Let it flow.

Now, when the inertia pendulum of the present invention is attached,
The optical axis of the corrected optical lens and the optical axis of the main lens are positioned
To return to the desired position (hereinafter referred to as the pendulum center)
The principle of torque generation will be described with reference to FIGS. 11 to 13.
It FIG. 11 is a sectional view seen from the direction of arrow A in FIG.
Yes, the coil 42 and the magnet 41 shown in FIG.
If the position of is the pendulum center, the magnetic field
The strength is set to an ideal magnetic field as shown in FIG.
At this time, the section 42a shown in the drawing inside the coil 42 is
An electric current is flowing from the back to the front, and the cross-section 42b has paper
Electric current flows from the front to the back. Coil 42 fixed
Therefore, F shown in the figure on the magnet 41 ₁ , F₂ Power of
Occurs.

Since the currents and magnetic fields flowing in the cross-sectional views 42a and 42b are the same, the forces F ₁ and F ₂ are clearly F ₁ =
There is a relationship of F ₂ . Moreover, since the directions of the forces F ₁ and F ₂ are opposite to each other, the forces F ₁ and F ₂ cancel each other and the resultant force is 0.
become.

However, when the magnet 41 has a positional relationship as shown in FIG. 11B as the gimbal rotates, the magnetic field applied to the cross section 42b becomes smaller than that of the cross section 42a.
Since the forces F ₁ and F ₂ are F ₁ > F ₂ , a force acts on the magnet 41 in the arrow direction shown in FIG.

Further, when the magnet 41 rotates in the opposite direction (not shown), the forces F ₁ and F ₂ become F ₁ <F ₂ , and a force for returning to the pendulum center direction acts similarly to the above. .. The resultant force and the positional relationship of the magnet 41 at this time are shown in the graph of FIG.

When the magnet 41 is near the pendulum center, the strength of the magnetic field does not change even if the magnet 41 moves a little, so that F ₁ = F ₂ and the resultant force is 0, but when the magnet 41 moves greatly. , F ₁ and F ₂ are out of balance, and a force that returns toward the pendulum center is generated. At this time, as shown in FIG.
Since the intensity of the magnetic field of No. 1 is non-linearly magnetized, the force has a non-linear curve as shown in FIG.

The supporting member 3, which is an inertial pendulum, is supported by a girbal 5 having a degree of freedom with respect to X and Y axes. Therefore, the movement of the magnet 41 has been described with respect to the generation of torque with respect to the movement of the support member 3 around the Y axis. However, as shown in the figure, the same principle is applied to the movement around the X axis around the Y axis. A return force is generated.

That is, as shown in FIG. 12, a pair of magnets 41 and coils 42 can generate forces in two axial directions. This shows that a non-linear control torque is applied to the deflection angle of the support member 3 in order to satisfy the two factors of the image stabilization and the prevention of the excessive movement of the lens portion related to the panning.

To explain this meaning, in order not to disturb the movement of the correction optical system, that is, the movement of the support member 3, in order to prevent the movement of the support member 3 for image stabilization near the center,
It gives almost no torque for damping.

However, when a large movement in one direction is applied, such as panning, a large torque for pulling back to the center is generated so that the lens portion of the support member 3 does not hit the inner wall of the lens barrel 4. It is configured like.

As described above, the torque for returning the support member 3 to the center direction described above is a countermeasure against a large movement such as panning, and is a negative action for the original purpose of vibration isolation. It is better to have less.

[0067]

As described above, according to the first aspect of the present invention, the correction means for correcting the image blur is provided so that the image stabilization characteristics are different in the horizontal direction and the vertical direction, and the correction means is movable. Since the torque is applied to the correction means in the direction of inclination of the line connecting the center position and the current position, the limited correctable deflection angle of the correction means can be effectively utilized, and the vibration isolation effect is visually extremely high. A high vibration isolation system has become feasible.

Since it can be used in a state where the optical characteristics of the central part of the optical axis are good and there is no need to perform switching operations such as camera shake and pan, when it is applied to consumer video, pan and tilt and camera shake are common. When it becomes possible to cope with the usage situation, there is an effect that the operability and the quality of the image can be significantly improved.

Further, according to the second aspect of the invention, since a constant current is passed through the coil forming the torque generating section to make the magnetizing curve of the magnet non-linear, a non-linear force curve corresponding to the displacement of the magnet. Can be obtained, and a control circuit becomes unnecessary. Since a pair of actuators can generate a force on two axes, the number of actuators can be reduced, and a large cost reduction can be expected.

[Brief description of drawings]

FIG. 1 is a characteristic diagram of a control torque with respect to a swing angle of an inertial swinger.

FIG. 2 is a longitudinal sectional view showing an embodiment of the invention described in claim 1.

FIG. 3 is an exploded perspective view showing a configuration of a sensor unit.

FIG. 4 is an exploded perspective view showing a configuration of a torque generating section.

FIG. 5 is a block diagram showing a configuration of a control unit.

FIG. 6 is a flowchart showing a processing procedure of a microcomputer.

FIG. 7 is a diagram illustrating the meaning of torque.

FIG. 8 is a diagram illustrating the meaning of torque.

FIG. 9 is a vertical cross-sectional view showing an embodiment of the invention according to claim 2;

FIG. 10 is an exploded perspective view showing a configuration of a torque generation unit.

FIG. 11 is a diagram showing the principle of an actuator.

FIG. 12 is a diagram showing the principle of an actuator.

FIG. 13 is a characteristic diagram of generated force with respect to a magnet position.

FIG. 14 is a vertical sectional view of a conventional image blur correction device.

FIG. 15 is an explanatory diagram of gimbal support.

FIG. 16 is an explanatory diagram of a magnetic effect.

[Explanation of symbols]

 2 movable lens 3 support member 4 lens barrel 5 gimbal (image shake correction means) 41 magnet 42 coil T torque generation unit (torque generation means)

Claims (2)

[Claims] 1. A support member for supporting a movable lens, an image shake correction means for supporting the support member on a lens barrel with different image stabilization characteristics in horizontal and vertical directions, and a movable center position of the image shake correction means. And an image shake correction device, which includes a torque generating unit that applies a torque to the support member in an inclination direction of a line connecting the current position and the current position. 2. A support member for supporting a movable lens, an image shake correction unit for supporting the support member on a lens barrel with different image stabilization characteristics in horizontal and vertical directions, and a movable center position of the image shake correction unit. And a torque generating means for applying a torque to the support member in a tilt direction of a line connecting the current position and the current position. The torque generating means is composed of a coil for flowing a constant current and a magnet having a non-linear magnetization curve. An image blur correction means, wherein a restoring force to the optical neutral point of the support means is generated by the torque generation means.