JPH07198356A - Detection apparatus of angular displacement - Google Patents

Abstract

PURPOSE:To obtain the detection apparatus which miniaturizes an image-blur correction device using a VAP, which makes the device low-cost and which reduces a load at the same time. CONSTITUTION:The front of a VAP 1 is fixed, the VAP is used also as a protective glass, and only the rear us driven. A moving face is supported by a bellows- shaped film 1-4. Actuators 8P, 8Y are arranged at an interval of 90 deg. so as to eliminate a cross talk. A vertical-angle sensor is constituted in such a way that it makes light-emitting luminous fluxes of an iREF 10P parallel and that it is sensitive to only a change in the angle of the VAP 1, and it is arranged so as to eliminate the cross talk.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is produced by the movement of optical devices such as video cameras, silver halide cameras, binoculars, etc.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image blur correction device for correcting movement of an image, so-called image blur.

[0002]

2. Description of the Related Art Conventionally, an image blur correction device using a variable apex angle prism has a structure shown in FIG. A variable apex angle prism 101 is a transparent plate such as glass. 101
-1P and 101-1Y, and support frames 101-2P and 10 that support the transparent plates 101-1P and 101-2Y.
1-2Y, support frames 101-2P and 101-2Y are reinforced. Reinforcing rings 101-3P and 101-3
Y, a bellows film 101-4 connecting the support frames 101-2P and 101-2Y, and a high refractive index transparent liquid (not shown) filled in the formed internal space. Reference numeral 102 denotes a part of a lens barrel which incorporates an image blur correction device using a variable apex angle prism.
Reference numerals 03b and 103c are parts of the lens group of the optical system. Reference numeral 104 denotes a support body fixed to the lens barrel, in which a blind hole 104aY and a through hole 104bY are formed coaxially to form a swing axis YY for swinging one surface of the variable apex angle prism 100a in the yawing direction. is doing. Although not shown, the variable apex angle prism 101 is perpendicular to the Y-Y axis.
It also has a swing axis P-P for swinging the other surface in the pitching direction. Reference numeral 105Y is a holding frame for holding the variable apex angle prism 101, which has a shaft-shaped projection that fits into the blind hole 104aY and that fits into the through hole 104bY.
Is press-fitted and supported so as to be swingable around the swing axis Y-Y. Further, the pin 106Y is urged by the leaf spring 107Y and holds the position of the holding frame 105Y with respect to the blind hole 104aY. 105P is a variable apex angle prism 101
Numeral 108 is a holding frame for holding the variable apex angle prism 101 and is supported by the same structure as the swing axis Y-Y so as to be swingable around the swing axis P-P in the pitching direction. , A transparent protection plate that protects against external force and dust, and 109 is a Y holding frame.

In addition, the variable apex angle prism 101 has a variation in thickness caused by a manufacturing error and a reinforcing ring 101-.
It has coaxial variations of 3P and 101-3Y. Reinforcement ring 101-3Y to absorb coaxial misalignment
The holding frame 105Y is fitted with the reinforcing ring 10
The 1-3P and the holding frame 105P have a gap in the radial direction. Further, in order to absorb the variation in thickness, each has a gap in the thrust direction, and by filling the gap with an adhesive at the time of assembly, both surfaces of the variable apex angle prism 101 are swung with respect to the swing axes YY and Y, respectively. PP
It is swingably supported on.

[0004]

However, in the above-mentioned conventional example, since both surfaces of the variable apex angle prism are independently rocked in the pitching direction or the yawing direction, a rocking space for each surface is required. In addition, when it is arranged at the forefront of the optical system, there is a drawback that a protective member is required, a required space becomes large, and the cost also becomes high.

[0005]

The present invention is characterized by having an angular displacement detection means for optically detecting only the angular displacement of a movable member. With this configuration, only the angular displacement can be accurately detected even if the movable member undergoes angular displacement with parallel movement.

[0006]

1 and 2 show an embodiment of the present invention, and FIG. 1 shows a sectional view of a main part. 1 is a variable apex angle prism, 1-1U and 1-1M, which are transparent plates such as glass,
Support frame 1-2 for supporting the transparent plates 1-1U and 1-1M
U and 1-2M, reinforcing rings 1-3U and 1-3M that reinforce the support frames 1-2U and 1-2M, and a bellows-shaped film 1 that connects the support frames 1-2U and 1-2M.
-4 and a transparent liquid (not shown) having a high refractive index filled in the formed internal space. Reference numeral 2 is a part of a lens barrel incorporating an image blur correcting device using a variable apex angle prism, and 3a, 3b and 3c are parts of a lens group of the optical system. Reference numeral 4 denotes a support fixed to the lens barrel 2. Reference numeral 5 is a fixed frame for fixing one surface of the variable apex angle prism 1 to the support 5, and 6 is a support frame glued to the other surface of the variable apex angle prism 1. Coils 7P and 7Y (not shown in FIG. 1) are fixed to the support frame 6 by adhesion or the like at positions such that the directions from the optical axis are orthogonal to each other. An upper yoke 8P-1 and a lower yoke 8P-3, which is a back yoke of the magnet 8P-2, are arranged with a certain gap on both sides of the coil 7P to form a magnetic circuit to form an actuator 8P (the upper yoke and the magnet are It is held by a space member (not shown). Then, by energizing the coil 7P, Lorentz force is generated to drive the support frame 6. An actuator 8Y (not shown in FIG. 1) is also arranged in the coil 7Y in the same configuration, and the actuators 8P and 8P are provided.
The combined force of Y acts on the support frame 6. The support frame 6 is bonded to the fixed portion only by the flexible bellows film 1-4, and the liquid sealed inside the variable apex angle prism 1 has a constant volume. When the synthetic force acts, the movable surface of the variable apex angle prism 1 (the surface supported by the support frame 6) pivots about a moderate center to form a prism apex angle.

FIG. 2 is an exploded perspective view of movable parts, and the same parts are designated by the same reference numerals. 9 is a reflector,
It is fixed to the support frame 6 by screws and has a pitch reflection surface 9P and a yaw reflection surface 9Y, and the directions of both reflection surfaces are orthogonal to each other. Further, both reflecting surfaces are arranged parallel to the actuators 8P and 8Y, respectively.

Reference numeral 10P designates a lens-equipped I which is a light emitting element for irradiating a parallel light flux of infrared rays at a certain angle on the reflecting surface 9P.
Reference numeral 11P denotes a RED element, 11P denotes a PSD element that is an element for receiving the infrared parallel light flux reflected by the reflection surface 9P, and the IRED element with lens 10P and the PSD element 11P are provided by a holder 12P (not shown in FIG. 2). The above-mentioned combination, which is held and fixed to the holder 4 on the holder, constitutes an apex angle sensor in the pitch direction. Also in the yaw direction, as shown in FIG. 2, a yaw direction apex angle sensor is provided.

Next, the apex angle sensor will be described with reference to FIGS. 3 (a), 3 (b) and 3 (c). The same members are given the same numbers, but the pitch and yaw suffixes P and Y are omitted.

FIG. 3A shows a state when the swing angle is 0 degree, and the infrared parallel light flux emitted from the IRED element with lens 10 is reflected by the reflection plate 9 and the slit opening formed in the holder 12. The light flux transmitted through the section 125 is applied to the PSD element 11. Next, in FIG. 3B, a state in which the reflector 9 is swung by θ with the swing axis R being the axis is shown. The reflected light flux of the infrared parallel light flux emitted from the lens-equipped IRED element 10 on the reflecting plate 9 is inclined by 2θ compared to the state of FIG. 3A because the reflecting plate is inclined by θ.
Therefore, the light flux that passes through the slit opening 125 allows the PSD element 11 to obtain an output according to the distance from the slit portion to the PSD element 11. Next, in FIG. 3A, which describes the output change due to the parallel movement of the reflection plate, it is apparent that the output obtained from the PSD element does not change even if the reflection plate 9 moves in parallel in the plane. Figure 3
(C) shows a state in which the reflector 9 is translated in the direction perpendicular to the surface (arrow A). Even in this state, the reflector 9
It can be seen that the parallel light flux reflected by is only translated in the direction of arrow B, and the output obtained from the PSD element does not change. That is, in this sensor configuration, if the diameter of the bundle of infrared parallel rays emitted from the IRED element with lens 10 is sufficient, the output obtained is proportional to only the angular change of the reflection plate 9, and its spatial position.・ It is understood that there is no output / change in change.

Next, referring to FIG. 4, the independence of the vertical angle sensors in the pitch and yaw directions will be described. 9P and 9
As shown in FIG. 2, Y is a reflecting plate for reflecting the infrared parallel light flux in the pitch and yaw directions, and the x-axis and the y-axis correspond to the swing axes in the pitch and yaw directions, respectively. The circle in the figure represents 1_1U which is the movable surface (glass surface) of the variable apex angle prism. Now, consider a case where the movable surface 1_1U of the variable apex angle prism oscillates by θ about an axis of an angle of 0 from the y-axis (yaw axis) as shown in the figure. If the inclination of the movable surface in the pitch and yaw directions at this time is α = θsin0 β = θcos0 α · β can be detected by the apex angle sensor, the independence of the apex angle sensor in the pitch and yaw directions is completely maintained. . As described above, since the sensor output is proportional to the inclinations of the reflecting surfaces 9P and 9Y, the inclinations of the reflecting surfaces 9P and 9Y are obtained.
_Let each angle be α _r and β _r, and set θ << 1 to 4 of θ.
When arranging by ignoring the higher-order minute terms higher than the order, tan α _r = tan α-1 / 6 θ ³ · sin0 cos ²
0 tan β _r = tan β −1/6 θ ³ cos 0 sin ² 0, the second term on the right side is a third-order term of θ, and, for example, when θ = 3 deg, the second term is the first term even in the worst case.
It is about 1/1000 of the term. Therefore, although there is crosstalk in the pitch and yaw apex angle sensors, the amount is practically no problem.

Next, FIG. 5 shows a block diagram of an image blur correction device using a variable apex angle prism. Reference numeral 1 is a variable apex angle prism, and 20 is a photographing optical system in which the variable apex angle prism 1 is arranged at the forefront. Reference numeral 21 denotes a vibration gyro which is an angular velocity sensor and is fixed to a fixing member of the device, and outputs the angular velocity of the device as a signal. The angular velocity signal is subjected to processing such as BPF by the signal processing circuit 22 and integrated by the integrator 23 to become the angle signal a of the device. Reference numeral 24 denotes the apex angle sensor described above, which outputs a signal proportional to the apex angle of the variable apex angle prism 1. This signal is amplified by the signal processing circuit 25,
The apex angle signal b is obtained by filtering and the like. In the adder circuit 26, the angle signal a of the device and the apex angle signal b of the variable apex angle prism are added with opposite polarities to obtain a signal c. A signal c is amplified by an amplifier 27 and converted into a drive signal by a drive circuit 28. By driving 29, the prism apex angle of the variable apex angle prism is changed.

In this block configuration, blocks 24 to 29 are arranged so that the signal c becomes zero, that is, the angle signal a of the device and the apex angle signal b of the variable apex angle prism 1 become equal.
A feedback circuit including the variable apex angle prism 1 is formed. Since the variable apex angle prism 1 is driven in a direction in which the movement of the device is canceled, the state of the light beam incident on the imaging optical system 20 does not change and the image blur can be corrected. In FIG. 5, the configuration of only one axis (pitch or yaw direction) is shown. However, as described above, since the apex angle sensors in the pitch and yaw directions are practically kept independent, the coaxial configuration is used for the pitch. By independently controlling the and the yaw directions respectively, the image blur correction in the pitch and yaw directions can be realized by driving only one surface of the variable apex angle prism.

The present embodiment described above has the following unique effects.

1. Since the support mechanism for the movable surface of the variable apex angle prism does not have a sliding bearing such as a pin and a hole, there is no unnecessary load due to friction.

2. The apex angle sensor output depends only on the angle of the movable surface of the variable apex prism, and in the feedback control for the target angle signal, the bellows film portion of the variable apex prism is not forced to be deformed unnaturally (the movable surface is Since it swings around the shaft to be swung), it is possible to drive with a minimum driving force.

3. Since the output of the apex angle sensor is sensitive only to the angle, image blur correction is possible even if there are variations in manufacturing of the variable apex angle prism element (thickness variations, coaxial variations on both sides, accordion of the bellows film, etc.). Does not adversely affect the performance of the function.

4. Since the support mechanism for the movable surface of the variable apex angle prism does not have bearings such as pins and holes, and the output of the apex angle sensor is sensitive only to the angle, image blur correction is performed against environmental changes. The function performance is stable. For example,
Even if the thickness of the variable apex angle prism changes due to high or low temperature or high or low pressure, the load does not increase due to the increase of the lateral pressure of the bearing because there is no bearing. In addition, there is no risk of the bearing being oiled or dust entering due to durability. Further, even if the bellows-shaped film causes a creep phenomenon and the position of the movable surface is slightly displaced due to being left at a high temperature, the output of the apex angle sensor does not change.

5. Movable surface angle of variable apex angle prism (angle of reflective surface)
Can be detected with twice the sensitivity, so if the same sensitivity is used,
The distance between the slit portion and the PSD element can be halved, which is advantageous in terms of space. Further, since it is not necessary to dispose the electric element on the movable portion side, there is no increase in load due to wiring or the like.

In the above-mentioned embodiment, the reflecting surface of the pitch and yaw apex angle sensor is arranged in the direction perpendicular to the movable surface 1-U of the variable apex angle prism 1. The position of the apex angle sensor is not limited to the above position because it has sensitivity only to the movable surface 1-U of the variable apex angle prism 1. Is also good.

Although the vibrating gyroscope or the like is used as the image blur detecting means in each of the above-described embodiments, another angular velocity meter or another sensor such as an angular displacement meter or an angular velocity meter may be used.

Further, in each of the above-described embodiments, the case where the variable apex angle prism as the image blur preventing means is applied to the video camera has been described, but it may be applied to a silver halide camera or other optical equipment. Further, the image blur preventing means may be provided in an image pickup device such as a video camera or a silver salt camera, or may be provided in an interchangeable lens or an adapter which is detachable from the video camera or the silver salt camera.

In each of the above embodiments, the rear surface on the optical axis of the variable apex angle prism is driven, but the front surface or both surfaces may be driven.

[0024]

As described above, according to the present invention, even if the movable optical member is angularly displaced along with the parallel movement,
Only angular displacement can be detected accurately. Moreover, the degree of freedom in the method of supporting the movable member is increased thereby.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of an image blur correction device according to an embodiment of the present invention.

FIG. 2 is a culture perspective view of a movable part.

FIG. 3 is an explanatory diagram of a vertical angle sensor.

FIG. 4 is a diagram illustrating independence of apex angle sensors.

FIG. 5 is a block diagram of an image blur correction device.

FIG. 6 is a cross-sectional view of main parts for explaining a conventional example.

[Explanation of symbols]

 1 Variable Vertical Angle Prism 2 Lens Barrel 3 Part of Optical System 4 Support 5 Fixed Frame 6 Support Frame 7 Drive Coil 8 Actuator 9 Reflective Surface 10 Light Emitting Element 11 Light Receiving Element

Claims (2)

[Claims] 1. An angular displacement detection device comprising an angular displacement detection means for optically detecting only the angular displacement of a movable member. 2. The angular displacement detecting means includes a light emitting means for emitting parallel light, a reflecting means for reflecting the light emitted from the light emitting means, and a light receiving means for receiving the reflected light. The angular displacement detection device according to claim 1, wherein