JP2014224983A - Image stabilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a telescope image stabilizer that compensates deterioration of an observation image to be generated by receiving oscillation and the like in a telescope such as a monocular or a binoculars, and has a structure enabling reduction in costs and downsizing to be attained.SOLUTION: As means for anchoring an outer frame of a gimbal suspension device composed of an inner frame having the erect prism mounted, a middle frame and an outer frame to a housing of a telescope composed of an objective lens, an erect prism, and an eyepiece lens, and for rotating the middle frame rotatably mounted to the outer frame, and the inner frame rotatably mounted to the middle frame, an image stabilizer includes two voice coil motors. A first yoke part having a coil member of two voice coil motors is mounted on a drive circuit substrate of the voice coil motor mounted to the middle frame, and a second yoke part having a permanent magnet is arranged at the inner frame and the outer frame, respectively so as to face the first yoke part on the drive substrate. The image stabilizer causes the gimbal suspension device to be rotated by the voice coil motor allowing the first yoke and the second yoke part to relatively move.

Description

  This invention stabilizes the image of a telescope that compensates for the deterioration of the observed image caused by fluctuations in the emission angle of the light beam emitted from the observation object with respect to the optical axis of the telescope due to vibrations such as camera shake of a monoscope or binoculars. The present invention relates to a conversion device.

When operating the telescope to observe the observation object while holding a telescope represented by monoculars and binoculars by hand, especially when bringing it into an aircraft or vehicle, etc. Vibration or the like is added to the housing, which causes camera shake, but due to camera shake, the emission angle of the light beam from the observation target with respect to the optical axis fluctuates, and as a result, the observation image (optical image) of the observation target is blurred, The observed image may be deteriorated, for example, the resolution is deteriorated. Even if the amplitude of the vibration applied to the telescope is small, in the telescopes such as monoculars and binoculars, the field of view is narrow and the image of the objective lens is enlarged by the eyepiece, so that the observed image is deteriorated. Can not be ignored.

  So far, various image stabilization devices have been proposed that compensate for deterioration due to camera shake of an observation image observed with a telescope.

  As conventional binoculars with a camera shake compensation function, for example, an image stabilizing optical device disclosed in Patent Document 1 includes a pair of left and right objective lenses, a pair of left and right eyepieces, a pair of left and right objective lenses, and a pair of left and right eyepieces. The optical system is composed of a pair of left and right erect prisms arranged in the vertical direction with respect to the optical axis in the middle of one prism holding frame that holds the pair of left and right erect prisms, and the objective lens and the eyepiece lens. A gimbal suspension device that supports the prism holding frame so as to be rotatable about two rotation axes that are orthogonal to each other in a plane, and a gyro motor that is attached to the gimbal suspension device.

  The image stabilizing optical device disclosed in Patent Document 1 holds a pair of left and right erect prisms with one prism holding frame, and drives a gimbal suspension having this prism holding frame with one gyro motor. The drive mechanism can be simplified.

  However, when this image stabilizing optical device responds to the vibration in the lateral direction of the optical device, the vertical axis at the center of the left and right erecting prisms, that is, the intersection point O shown in FIGS. When the prism holding frame is rotated around, for example, the erecting prism of the left optical system moves to the objective lens side, and the erecting prism of the right optical system moves to the eyepiece lens side. The distance between the vertical prism and the distance between the objective lens of the right optical system and the erecting prism will be different. As a result, the view through the right optical system is different from the view through the left optical system. Will be different. In other words, the image stabilizing optical device described in Patent Document 1 is configured to process the vibration in the left-right direction, and the positional relationship between the plurality of optical components constituting the right optical system and the plurality of opticals constituting the left optical system. There is a problem in that the same positional relationship between the components is lost, and the way the right optical system looks and the left optical system looks different.

  The image stabilization apparatus disclosed in Patent Document 2 is the same as the image stabilization optical apparatus described in Patent Document 1 with respect to the optical system, and includes a pair of left and right objective lenses, a pair of left and right eyepieces, and a pair of left and right eyes. A pair of left and right erecting prisms disposed between the objective lens and the pair of left and right eyepieces, a prism holding frame that holds the pair of left and right erecting prisms, and an optical axis between the objective lens and the eyepiece. And a gimbal suspension means for supporting the prism holding frame so as to be rotatable around two axes orthogonal to each other in a plane perpendicular to the plane, and by means of vibration applied to the telescope by the angular velocity information detecting means arranged on the prism holding frame The generated rotation angle information with respect to the inertial space of the gimbal suspension means is detected, and based on this detected value, the image blur due to vibration is corrected. The Nbaru suspension means is performed a servo control to rotate to return to a predetermined position.

  In the image stabilization device described in Patent Document 2, as a drive mechanism of a gimbal suspension device, a drive using a rotary type motor that rotates a gimbal rotation shaft instead of a gyro motor and position detection means such as a potentiometer. Since the mechanism is adopted, it is said that the light weight and the small size can be achieved and the power consumption can be reduced as compared with the image stabilization apparatus described in Patent Document 1.

  However, the image stabilization apparatus described in Patent Document 2 is effective in reducing the size of a binocular optical system having two erecting prisms. However, a monocular optical system having one erecting prism is used. On the other hand, since the rotary type motor that rotates the gimbal shaft and the position detection means such as a potentiometer require a relatively large space, it is not suitable for downsizing the apparatus.

  An observation optical device (binoculars) described in Patent Document 3 includes a pair of left and right objective lenses, a pair of left and right eyepieces, a pair of left and right objective lenses, and a pair of left and right eyepieces. A variable apex prism, a sensor for detecting the shake of the device main body, a plurality of actuators for driving the pair of left and right variable apex angle prisms, and a control circuit for determining the drive amount of each actuator according to the shake detected by the sensor And.

  The binoculars with a camera shake correction mechanism described in Patent Literature 4 includes a pair of left and right objective lenses, a pair of left and right eyepieces, and a pair of left and right objective lenses and a pair of left and right eyepieces. And a sensor for detecting the shake of the device main body, a drive mechanism for simultaneously driving the pair of right and left correction lenses, and a control circuit for determining the drive amount of the drive mechanism in accordance with the shake detected by the sensor.

Although the methods of Patent Document 1 and Patent Document 2 have the advantage that the range of practical use is wide, there is a problem that there is a limit to reducing the size and weight of the image stabilization device.
Although the image stabilization means described in Patent Document 3 and Patent Document 4 have the advantage that the mechanism is small, the amount of blurring that can be corrected is small compared to the examples of Patent Documents 1 and 2, and is practical. There is a problem that the range to be used is narrow.

Japanese Patent Publication No.57-37852 JP-A-6-250100 Japanese Unexamined Patent Publication No. 7-43645 Japanese Patent Laid-Open No. 10-20213

An object of the present invention is to provide a telescopic optical system represented by monoculars or binoculars in which an erecting prism is disposed between an objective lens and an eyepiece, and the erecting prism is orthogonal to the optical axis of the telescopic optical system, and In an image stabilization device that compensates for deterioration of an observed image caused by vibration such as camera shake by rotating around two rotation axes that are orthogonal to each other, the gimbal of the main element constituting the image stabilization device An object of the present invention is to provide means for configuring the drive of the suspension device in a small size, light weight and low cost.

Means for solving the problems are as follows:
(1) The erecting prism of the telescope optical system in which the erecting prism is disposed between the objective lens and the eyepiece lens is configured so that the first rotation axis and the second orthogonal to the optical axis of the telescope optical system and to each other An image stabilization device that compensates for deterioration of an observed image caused by vibration such as camera shake by rotating around a rotation axis,
A housing that holds the objective lens and the eyepiece lens fixedly;
An outer frame fixed to the housing;
A middle frame having a first pivot shaft rotatably mounted on the outer frame;
A gimbal suspension device having an inner frame having a second rotation shaft that is rotatably mounted on the middle frame;
The gimbal suspension includes two voice coil motors for driving the middle frame and the inner frame,
The voice coil motor includes a first yoke portion including a coil member having a position detection element disposed in a hollow portion of the coil, and a second yoke portion including a permanent magnet.
The middle frame is provided with a drive circuit board for driving two voice coil motors,
A coil member constituting the first yoke portion of the voice coil motor that drives the inner frame is disposed on the outer frame side surface of the drive circuit board, and the permanent magnet of the second yoke portion is used as the first yoke portion. The second yoke portion is attached to the outer frame so as to face the coil member with a gap of a predetermined interval,
A coil member constituting the first yoke portion of the voice coil motor that drives the inner frame is disposed on the inner frame side surface of the drive circuit board, and the permanent magnet of the second yoke portion is used as the first yoke portion. The second yoke portion is attached to the inner frame so as to face the coil member with a gap of a predetermined interval,
The inner frame is an image stabilization device provided with the erecting prism,
(2) The image stabilizing device according to (1), wherein an angular velocity sensor is provided in an inner frame of the gimbal suspension device to obtain an angular velocity signal,
(3) The image stabilization according to (1), wherein an output signal of a position detection element disposed in a hollow coil portion of the first yoke portion is differentiated to obtain a position signal and an angular velocity signal from the position detection element. Device,
(4) The drive circuit board is configured by a circuit that controls the rotation of the gimbal suspension device by driving the voice coil motor to hold the initial position of the erecting prism based on the position signal and the angular velocity signal. (2) or (3), wherein the image stabilizing device is characterized in that
(5) The image stabilization apparatus according to any one of (1) to (4), wherein the telescope optical system is a monocular.
(6) The image stabilization apparatus according to any one of (1) to (4), wherein the telescope optical system is binoculars.

The image stabilization apparatus according to the present invention can compensate for deterioration of an observed image caused by vibration such as camera shake applied to a telescope such as a monocular or a binocular, and has few restrictions on design freedom of the image stabilization apparatus, and the gimbal. Since the drive mechanism is simple and can reduce cost and size, it can be used in a wide range of fields such as telescope monoculars and binoculars as well as laser rangefinders, especially when applied to monoculars. Great effect in miniaturization and cost reduction.

FIG. 1A is a schematic explanatory view showing an image stabilization apparatus when the image stabilization apparatus according to the present invention is a monocular, and FIG. 1B shows the basic principle of the image stabilization apparatus. It is a schematic explanatory drawing to explain. FIG. 2 is a schematic explanatory view showing an image stabilization apparatus when the image stabilization apparatus according to the present invention is a binocular. FIG. 3 is a schematic explanatory view showing the basic structure of the voice coil motor, and FIG. 3A is a front view of the voice coil motor. 3B is a cross-sectional view taken along the line AA ′ of FIG. 3A, FIG. 3C is a front view of the permanent magnet incorporated in the voice coil motor, and FIG. 3D is a cross-sectional view of the permanent magnet. FIG. FIG. 4 is a schematic explanatory view showing the structure of a yoke-separated voice coil motor suitable for incorporation in the image stabilization apparatus according to the present invention, and FIG. 4 (a) is a sectional view showing the voice coil motor. FIG. 4B is a cross-sectional view showing a state in which the coil member in the voice coil motor has moved relative to the permanent magnet. FIG. 5 is an explanatory view showing the structure of the gimbal suspension apparatus 10 of FIG. 1, which is an example of the image stabilization apparatus according to the present invention. FIG. 5 (a) is a schematic perspective view, and FIG. It is sectional drawing of 5 (a). FIG. 6 is a perspective view centering around the periphery of the drive circuit board. FIG. 7 is an explanatory view showing a driving state of the middle frame of the gimbal suspension apparatus. FIG. 8 is an explanatory view showing a driving state of the inner frame of the gimbal suspension. FIG. 9 is a block diagram showing an example of a drive circuit for driving the voice coil motor. FIGS. 10A and 10B are block diagrams showing another example of a drive circuit for driving the voice coil motor.

  FIG. 1 shows an example of an image stabilization apparatus as monoculars according to the present invention, and FIG. 2 shows an example of an image stabilization apparatus as binoculars according to the present invention.

  For example, as shown in FIG. 1, the image stabilization device according to the present invention has a gimbal suspension device 10 shown in FIG. 5, which will be described later, on the optical axis 6 of the objective lens 2 and the eyepiece 3 fixed to the housing 8. The upright prism 1 mounted on the inner frame 53 is disposed to constitute the monocular optical system 4. As shown in FIG. 1B, the erecting prism 1 has a structure that maintains the initial position before the hand shake is applied even when the case 8 is shaken.

When the image stabilization apparatus according to the present invention is applied to binoculars, for example, as shown in FIG. 2, the pair of monocular image stabilization apparatuses 4 and 4 ′ shown in FIG. The binoculars 5 are configured by connecting the connecting members R so that 6 and 6 'are parallel to each other.

  The image stabilization apparatus according to the present invention is applied to monoculars, binoculars, and the like. As shown in FIG. 1, the optical system in the image stabilization apparatus applied to monoculars, and FIG. As described above, since the optical system in the image stabilization apparatus applied to the binoculars is the same, the detailed description of the image stabilization apparatus below will be made using a monocular as an example.

  The image stabilization apparatus according to the present invention includes two voices as drive means for rotating a gimbal suspension apparatus equipped with an upright prism so as to compensate for deterioration of an observation image caused by vibration or swing applied to a casing. As described later, the voice coil motor has a first yoke portion and a second yoke portion that are separately arranged to face each other, and the first yoke portion detects a position in a hollow portion of the coil. For example, a coil member on which a magnetic sensing element such as a Hall element is disposed is mounted, and a permanent magnet having the structure described in FIG. 3 is mounted on the second yoke portion. The second yoke portion is disposed so as to face the gap having a predetermined interval, and the first yoke portion and the second yoke portion are relatively movable. In the present invention, a member provided with a position detection element for position detection in the hollow portion of the coil is referred to as a coil member.

  Examples of the erecting prism 1 include a Schmidt erecting prism and an Abbe erecting prism. In FIG. 1, a Schmidt erecting prism is shown. The Schmidt erecting prism 1 includes a prism 1a and a prism 1b, and a prism surface is formed on the prism 1b. The incident optical axis and the outgoing optical axis can be on the same straight line. The following description relates to the case of using a Schmidt erecting prism.

The gimbal suspension device 10 shown in FIG. 1A has a rotation shaft 54 extending in the left-right direction orthogonal to the optical axis 6 and a rotation shaft 55 extending in the up-down direction as shown in FIG.
The intersection p between the two rotation axes and the optical axis 6 is an optical distance L between the objective lens 2 and the entrance surface of the erecting prism 1 and a mechanical distance M between the entrance surface and the exit surface of the erecting prism 1. And the center of the sum S (S = L + M + N) of the optical distance N from the exit surface of the erecting prism 1 to the eyepiece 3 is set. Actually, since both the objective lens system and the eyepiece lens system are constituted by a plurality of lenses having a thickness, the position of the rotation shafts 55 and 54 of the gimbal suspension is strictly the objective lens system. The optical distance from the rear principal point to the entrance surface of the erecting prism, the mechanical distance from the entrance surface to the exit surface of the erecting prism, and the eyepiece lens system from the exit surface of the erecting prism. It is at the midpoint of the sum of the optical distances to the front principal point. Hereinafter, the objective lens and the eyepiece lens will be described as a thin lens system.

  FIG. 1B shows the basic principle of the image stabilization apparatus according to the present invention. When the telescope 4 shown in FIG. 1 (a) is subjected to vibration due to camera shake or the like, and the casing 8 is tilted at an angle θ as shown in FIG. 1 (b), the objective lens 2 and the eyepiece 3 are in the casing. Accordingly, the objective lens is moved to the 2 ′ position, the eyepiece lens is moved to the 3 ′ position, and the optical axis 6 is also moved to the optical axis 7. At this time, if the erecting prism 1 mounted on the gimbal suspension device 10 is controlled so as to be in the same direction as the initial state in FIG. 1A, it passes through the center q ′ of the tilted objective lens 2 ′ and before the angle θ is tilted. A light beam m parallel to the optical axis 6 is shifted from the optical axis 6 of the objective lens 2 by h and enters the upright prism 1. The light beam m is emitted from the erecting prism 1 as a light beam m ′ shifted by h ′ = h from the optical axis 6 due to the property of the erecting prism capable of taking the incident optical axis and the outgoing optical axis on the same line. The light is emitted from the center r ′ of the moved eyepiece 3 ′. Therefore, since the light beam m 'emitted from the center r' of the eyepiece after movement is parallel to the optical axis 6 before the vibration is applied, a stable and sharp image can be observed even when the telescope is vibrated.

  In FIG. 1B, the case where the rotation axis of the gimbal suspension is set at the center of the erecting prism has been described. However, the position of the intersection point P with the optical axis of the rotation axis of the gimbal suspension satisfies the above condition. In this case, the above condition is satisfied even when the erecting prism is disposed at a position shifted from the rotational axis of the gimbal suspension.

  In the prior art, as the means for driving the gimbal suspension apparatus, as shown in the cited document 2, a rotary motor for driving a rotation shaft for suspending the gimbal suspension apparatus and a position detection means such as a potentiometer. However, the rotary motor that drives the rotating shaft must have a relatively large shape compared to the frame that constitutes the gimbal suspension, and the shape of the mounting position, motor diameter, thickness, etc. Due to limitations, there has been a limit to reducing the size and weight of the image stabilization device.

In the present invention, as a means for driving the gimbal suspension, a relatively thin pair of plate-shaped yoke parts as shown in FIG. 4 is used, and the position detection means has a structure in which the position detection element is incorporated in the hollow part of the coil. By using a voice coil motor, the mounting position of the voice coil motor can be freely selected, so that the degree of freedom in design is increased and the size and weight can be reduced.

  FIG. 3 shows an example of a general voice coil motor. FIG. 3 (a) is a front view of the voice coil motor, and FIG. 3 (b) is a cross-sectional view taken along the plane AA 'of FIG. 3 (a). FIG. 3C is a front view showing the configuration of the permanent magnet used in the voice coil motor, and FIG. 3D is a cross-sectional view thereof.

  As shown in FIG. 3, a general voice coil motor has a fixed yoke 31 made of a U-shaped iron core, a permanent magnet 32 mounted on one opposing surface inside the fixed yoke, and an inner side of the fixed yoke. The coil 33 is movable in a gap 34 constituted by another surface, and a position detection element 36 installed in the hollow portion of the coil 33. Reference numeral 35 denotes a support plate such as a printed circuit board that supports the coil 33 and the position detection element 36.

As shown in FIGS. 3C and 3D, the permanent magnet 32 is composed of a strong plate-like permanent magnet. The permanent magnet is magnetized in the thickness direction, and the direction of magnetization is magnetized in the reverse direction as indicated by N and S with the central portion of the plate-like region as a boundary.

In order to facilitate understanding of the drawing, the S pole side is shown by hatching in the drawing. Further, the permanent magnets to be described below are assumed to have the structure described with reference to FIGS. 3 (c) and 3 (d).

  By arranging such permanent magnets 32 on the inner surface of the fixed yoke as shown in FIG. 3A, the magnetic field in the fixed yoke is opposite to each other with the central portion of the moving process of the coil 33 as a boundary. And is generated in a direction perpendicular to the facing surface having the gap of the fixed yoke.

  Therefore, when the coil 33 is arranged in the fixed yoke 31 having such a magnetic field as shown in FIG. 3 and a current is passed through the coil 33, the coil 33 is changed to an arrow in FIG. It can move in the direction indicated by 38.

  Therefore, the movable member can be linearly driven by connecting the movable member (not shown) to the support plate 35 of the coil 33.

  Further, by disposing a magnetic sensitive element such as a Hall element or a magnetoresistive element as the position detecting element 36 in the hollow portion 37 of the coil 33, a position detection signal for detecting the position of the movable coil can be output. . In particular, in the initial reference state of the voice coil motor, if the position detection element 36 is arranged so as to be positioned at the boundary between the permanent magnets S and N, the output of the Hall element becomes 0, so the initial reference position of the voice coil motor is determined. Convenient to.

  As shown in FIG. 4A, a preferred voice coil motor to be applied to the present invention is separated from the U-shaped fixed yoke 31 and separated into two having a plate shape. The first yoke portion 41 has a position detecting element 36 for position detection, for example, a magnetic element such as a Hall element, in the hollow portion of the coil 33. The coil 33 including the sensitive elements, the support plate 43, and the yoke plate 46 are configured. The second yoke portion 42 is configured by the magnet 32 and the yoke plate 47, and the first yoke portion and the second yoke portion are formed. It is characterized by a structure in which the first yoke part 41 and the second yoke part 42 are relatively movable so as to face each other with a gap 44 of a predetermined interval.

If a current is passed through the coil 33 of the first yoke portion 41, the first yoke portion 41 is integrated with the coil 33 to become a mover if the second yoke portion 42 is a stator depending on the direction of the current. For example, it moves in the direction of arrow 45 in FIG.

  If the first yoke portion 41 is a stator, the second yoke portion 42 relatively moves with the permanent magnet as a mover.

FIG. 5 shows the configuration of the gimbal suspension 10 which is a main element of the present invention. FIG. 5A is a perspective view of the gimbal suspension, and FIG. 5B is a cross-sectional view of the gimbal suspension device as seen in a plane including the rotating shafts 54 and 55 shown in FIG.

  The gimbal suspension apparatus 10 includes an inner frame 53, an intermediate frame 52, and an outer frame 51. The outer frame of the gimbal suspension apparatus 10 is mounted on the housing 8 that holds the objective lens and the eyepiece lens fixedly as shown in FIG. 51 is fixedly attached.

  As shown in FIGS. 5A and 5B, the gimbal suspension apparatus 10 includes a first rotating shaft 54 in which shafts 62a and 62b provided on the left and right side walls of the middle frame 52 extend in the left-right direction. It is formed and supported by bearings 63 a and 63 b provided on the outer frame 51, and the middle frame 52 is rotatably attached to the outer frame 51.

  The inner frame 53 forms a second rotating shaft 55 in which shafts 64a and 64b provided on the upper and lower side walls extend vertically, and is supported by bearings 65a and 65b provided on the inner frame 52. The erecting prism 1 is attached to the inner frame 53.

The gimbal suspension apparatus 10 includes two voice coil motors, a first voice coil motor 56 b that rotates the middle frame 52 and a second voice coil motor 56 a that rotates the inner frame 53. The first voice coil motor 56b has a first yoke portion composed of a coil member in which a position detecting element 57b is disposed in a hollow portion of the coil 58b, a yoke plate 59b, a yoke plate 61b, and a permanent magnet 60b. The first yoke portion and the second yoke portion are arranged to face each other with a predetermined interval.
The second voice coil motor 56a includes a first yoke portion composed of a coil member having a position detecting element 57a disposed in a hollow portion of the coil 58a, a yoke plate 59a, a yoke plate 61a, and a permanent magnet 60a. The first yoke portion and the second yoke portion are arranged to face each other with a predetermined interval.

  The first yoke portion constituting the second voice coil motor 56a is disposed and fixed on the drive circuit board 66 of the voice coil motor, and the coil 58a of the voice coil motor 56a is disposed on the inner frame side surface of the drive circuit board 66. The yoke plate 59a constituting the first yoke portion is disposed and fixed on the outer frame side surface of the drive circuit board 66. The second yoke portion constituting the second voice coil motor 56a is composed of a permanent magnet 60a and a yoke 61a, and is arranged and fixed to the inner frame 53 so as to face the coil 58a. In the voice coil motor 56a, the first yoke portion serves as a stator and the second yoke portion serves as a mover.

  The first yoke part constituting the first voice coil motor 56b is disposed and fixed to the drive circuit board 66 of the voice coil motor, and the coil 58b of the voice coil motor 56b is placed on the outer frame side surface of the drive circuit board 66. The yoke plate 59b constituting the first yoke portion is disposed and fixed on the surface of the drive circuit board 66 on the inner frame side. The second yoke part constituting the first voice coil motor 56b is composed of a permanent magnet 60b and a yoke 61b, and is arranged and fixed to the outer frame 51 so as to face the coil member 58b. In the voice coil motor 56b, the first yoke portion serves as a mover and the second yoke portion serves as a stator.

  By mounting the first yoke portions of the two voice coil motors on the drive circuit board 66 in this way, the coil member including the position detection element (Hall element) can be replaced with another circuit when the drive circuit board is created. It can be mounted in the same manner as the parts such as the microcomputer 92 and the voice coil motor driving driver 93, and assembly is facilitated.

  FIGS. 6, 7 (a), 7 (b), 8 (a), and 8 (b) are explanatory diagrams for explaining the operation of the two voice coil motors as the main elements of the present invention. In addition, the code | symbol of a component is represented by the same description as FIG.

  FIG. 6 is a perspective view for explaining the operation of the voice coil motor centering on the periphery of the drive circuit board 66 of the voice coil motor. For ease of explanation, FIG. 6 shows a second yoke corresponding to the first yoke portion. The gap of the yoke part is shown widened.

FIG. 7A is an explanatory view of the drive circuit board 66 of FIG. 6 as viewed from the middle frame 52 (right side), and shows a first yoke portion and a second yoke portion in an A-B cross section. The drive circuit board 66 rotates around a rotation shaft 54 extending in the left-right direction. FIG. 7A shows an initial reference position before vibration due to camera shake or the like is applied to the monocular. FIG. 7B shows a state in which the driving circuit board 66 is inclined by an angle θ due to vertical vibration caused by camera shake or the like on the monocular, and the middle frame 52 fixed to the driving circuit board 66 is also inclined by the angle θ. However, since the angle is small, there is no problem in the operation of the linear drive voice coil motor.

In the image stabilization apparatus according to the present invention, the range for compensating for vibration due to camera shake or the like is about ± 5 ° in angle (θ). Therefore, a control signal such as a position servo using a position signal from the position detection element is applied to the coil 58b. By adding, it is possible to easily return to the initial position of FIG.

FIG. 8A is an explanatory plan view of the drive circuit board 66 shown in FIG. 5 as viewed from above. The inner frame 53 rotates about a rotation shaft 55 extending in the vertical direction with respect to the drive circuit board 66. FIG. 8A shows the initial reference position of the inner frame 53 before vibration due to hand shake or the like is applied to the telescope. FIG. 8B shows a state in which the telescope is subjected to left-right vibration due to camera shake or the like, and the inner frame is tilted by an angle θ in the left-right direction. The inner frame 53 has the drive circuit board 66 and the drive circuit board 66 fixed thereto. A state in which the angle θ is inclined with respect to the middle frame is shown. Although the inner frame 53 moves in the direction inclined by the angle θ with respect to the drive circuit board 66 fixed to the middle frame, there is no problem in the operation of the linear drive voice coil motor because the angle is small.

  In the voice coil motor 56a that drives the inner frame 53, the first yoke portion on which the coil member is mounted is the stator, and the second yoke portion on which the permanent magnet is mounted is the mover, so the second yoke portion is fixed. When the vibration caused by hand shake or the like is applied, the inner frame 53 is rotated as shown in FIGS. 8A and 8B around the rotation shaft 55 extending in the vertical direction.

In this case, the range for compensating the vibration in the left-right direction due to camera shake or the like is set to about ± 5 ° in angle. Therefore, by adding a control signal such as a position servo to the coil 58a, the initial position shown in FIG. It is possible to return.

From the position information obtained from the Hall element as the position detection element, the target position for canceling the motion is calculated by a microcomputer, and the calculation result is fed back to the coil drive current of the voice coil motor as a control signal. A position servo system for moving the inner frame and the middle frame by the required amount can be configured.

FIG. 9 shows a block diagram of a voice motor driving circuit constituting the position servo system. Since the above-described voice coil motors 56a and 56b are basically the same, the following description will be made in the case of the voice coil motor 56a.

The position signal from the position detection element 57a attached to the voice coil motor 56a is taken into the microcomputer 92 via the position signal amplification circuit 91, and the target position for canceling the movement is set by adjusting the phase compensation filter calculation and the amplification factor. Then, a voice coil motor control signal for feedback driving for applying the position servo is calculated, and an amplification circuit 93 for amplifying the control signal based on this calculation and driving the voice coil motor 56a is provided.

In FIG. 10A, an angular velocity sensor 94 is mounted on the inner frame 53 of the gimbal suspension for mounting the erecting prism, the angular displacement of the erecting prism 1 caused by vibrations such as camera shake is detected, and the movement of the erecting prism is detected. By giving a target to cancel, a double feedback loop of position servo and angular velocity servo is formed. In the figure, reference numeral 95 denotes an amplification circuit for amplifying a signal from the angular velocity sensor, which is added to the microcomputer 92, calculates a control signal for the voice coil motor, amplifies the control signal based on this calculation, and drives the voice coil motor 56a. A circuit 93 is provided.

The angular velocity sensor 94 is a biaxial angular velocity sensor that detects the vertical and horizontal components of vibration and is used to calculate the control signals of the voice coil motors 56a and 56b. good.

FIG. 10B shows a differential circuit 96 that differentiates a signal from a position detection element 57a attached to the voice coil motor 56a instead of the angular velocity sensor, extracts an angular velocity signal simultaneously with the position signal, and a microcomputer 92 FIG. 2 is a block diagram of a voice coil motor drive circuit configured to calculate a motor control signal. In this case, the differentiation circuit 96 can be processed inside the microcomputer, and an expensive angular velocity sensor is not required, so that the effect of cost reduction is great.

DESCRIPTION OF SYMBOLS 1 Erect prism 1a, 1b Prism 2, 2 'Objective lens 3, 3' Eyepiece 4, 4 'Monocular 5 Binoculars 6, 6', 7 Optical axis 8, 8 'Case R Connecting member 10 Gimbal suspension 31 Fixed yoke 32, 60a, 60b Permanent magnet 33, 58a, 58b Coil 36, 57a, 57b Position detection element 35, 43 Support plate 59a, 59b First yoke plate 61a, 61b Second yoke plate 51 Outer frame 52 Middle frame 53 Inner frame 54 First rotation shaft 55 Second rotation shafts 56a and 56b Voice coil motor 66 Driving circuit board 92 Microcomputer 93 Voice coil motor driving driver 94 Angular velocity sensor

Claims (6)

The erecting prism of the telescope optical system in which the erecting prism is disposed between the objective lens and the eyepiece lens is arranged so that the first rotating shaft and the second rotating shaft are orthogonal to the optical axis of the telescope optical system and orthogonal to each other. An image stabilization device that compensates for deterioration of an observed image caused by vibrations such as camera shake,
A housing that holds the objective lens and the eyepiece lens fixedly;
An outer frame fixed to the housing;
A middle frame having a first pivot shaft rotatably mounted on the outer frame;
A gimbal suspension device having an inner frame having a second rotation shaft that is rotatably mounted on the middle frame;
The gimbal suspension includes two voice coil motors for driving the middle frame and the inner frame,
The voice coil motor includes a first yoke portion including a coil member in which a position detection element is disposed in a hollow portion of the coil, and a second yoke portion including a permanent magnet.
The middle frame is provided with a drive circuit board for driving two voice coil motors,
A coil member constituting the first yoke portion of the voice coil motor that drives the inner frame is disposed on the outer frame side surface of the drive circuit board, and the permanent magnet of the second yoke portion is used as the first yoke portion. The second yoke portion is attached to the outer frame so as to face the coil member with a gap of a predetermined interval,
A coil member constituting the first yoke portion of the voice coil motor that drives the inner frame is disposed on the inner frame side surface of the drive circuit board, and the permanent magnet of the second yoke portion is used as the first yoke portion. The second yoke portion is attached to the inner frame so as to face the coil member with a gap of a predetermined interval,
An image stabilization apparatus, wherein the erecting prism is provided in the inner frame.   2. The image stabilization apparatus according to claim 1, wherein an angular velocity sensor is provided in an inner frame of the gimbal suspension device to obtain an angular velocity signal.   2. The image stabilization apparatus according to claim 1, wherein an output signal of a position detection element disposed in a coil hollow portion of the first yoke portion is differentiated to obtain a position signal and an angular velocity signal from the position detection element.   The drive circuit board is configured by a circuit that controls a rotation of the gimbal suspension device by driving a voice coil motor so as to hold an initial position of the erecting prism based on a position signal and an angular velocity signal. The image stabilization apparatus according to claim 2 or 3.   5. The image stabilization apparatus according to claim 1, wherein the telescope optical system is a monocular. 5. The image stabilization apparatus according to claim 1, wherein the telescope optical system is binoculars.

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