JPH0886949A - Optical equipment - Google Patents

Abstract

PURPOSE: To stably move a lens without shake by providing the supporting part of a supporting member for movably supporting an optical holding member on an almost identical plane surface to the first part of a driving part and at an almost symmetric position with respect to the first part. CONSTITUTION: A permanent magnet 2 being a magnetic part as the movable first part constituting the driving part is fixed to the optical holding member 1 holding the optical member such as the lens. A coil 3 as a fixed second part constituting the driving part is fixed to the supporting member 5. Then, the vicinity of the magnet 2 on which driving force is actuated is the center of gravity of the movable part including the holding member 1. The holding member 1 is supported at the supporting parts 21 and 22 provided near and on both sides of the center of gravity on the supporting member 5. As for an actuator constituted of the magnet 2, the coil 3 and a yoke 8, the driving force is generated when a current is allowed to flow to the coil 3 and the holding member 1 is moved in an optical axis direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device for driving an optical member.

[0002]

2. Description of the Related Art In recent years, with advances in semiconductor chips such as memories and microcomputers, portable information devices have been expected to become smaller and higher in performance and to be widely used. Since this portable information device is carried in a pocket of a jacket for the purpose of customer management, it is required that the portable information device be compact and highly portable, and especially thin. Some of such information devices include a function of capturing a subject image, and in this case, in order to reduce the thickness, the entire image pickup system including the image pickup optical system and the drive mechanism system must be thinned.

FIG. 8 shows a zoom lens mechanism which is a conventional image pickup system. 101a is a first lens group, 101b is a second lens group, 101c is a third lens group, and 101d is a fourth lens group. Among them, the second lens group 101b is movable for zooming, and the fourth lens group 101d is movable in a predetermined range in the optical axis direction for focus adjustment. Reference numeral 102 is an optical low-pass filter, and 103 is an image pickup device such as a CCD.
Reference numeral 104 denotes a housing that holds the first lens group 1a, the third lens group 101c, the image sensor 103, and the like. Reference numeral 105 denotes an optical holding member for the second lens group, and 106 denotes the second lens group 10
It is a guide pin for guiding the operation of the optical axis direction 1b. 10
Reference numeral 7 denotes a screw member that engages with the optical holding member 105 of the second lens group 101b and conveys the second lens group 101b in the optical axis direction, and a biasing member 109 via a biasing spring 108.
The play between the optical holding member 105 and the optical holding member 105 is removed. The second lens group 101b is pivotally supported by the guide pin 106 and the screw member 107. 110 is a step motor, which is an optical holding member 1 for holding the second lens group 101b via the gear group 111 and the screw member 107.
Drive 05. The fourth lens group 101d is also held similarly, and in this case, the fourth lens group is conveyed in the optical axis direction by the engagement with the screw member 113 directly connected to the step motor 112. Reference numeral 114 is a diaphragm means, and the aperture diameter of the diaphragm is changed by a power source 115 such as a motor.

[0004]

In such a conventional example, if the sensitivity of the lens is increased as the size of the lens is reduced, it is necessary to improve the positional accuracy of the lens, and a minute change in the lens position gives a photographed image. There was a problem that the impact would be large. Particularly, in a video camera, a so-called “image shake” in which a captured image fluctuates due to the lens swinging during lens movement has become a problem. Further, in the still camera, a slight change in the lens position causes a large deviation from the pin, or the zoom magnification changes. This is a problem that occurs because the contact between the guide pin that guides the operation of the lens and the optical holding member that holds the lens is unstable. To solve this problem, for example, in Japanese Unexamined Patent Application Publication No. 4-5607, a fixed cylinder and a movable cylinder are guided by ball bearings arranged in guide grooves provided in each cylinder, and from the opposite side by a vibrating body of an ultrasonic motor. A mechanism has been disclosed in which a movable cylinder is driven in the optical axis direction by an ultrasonic motor without being loosened while being pressed. However, since this ultrasonic motor is driven by generating a traveling wave at the interface with the driven body, the friction characteristics of the interface such as surface roughness greatly affect the drive characteristics, and quality control is difficult. In addition, the fixed cylinder and the movable cylinder are installed in the optical axis direction differently from each other, and the ultrasonic motor as an actuator is installed in the optical axis different from the vertical direction, and the movable cylinder is inserted into the fixed cylinder through the ball bearings. It required complicated operations.

An object of the present invention is to provide an optical apparatus having a small size and a simple structure capable of stably moving the lens so that the lens does not swing during the movement of the lens and obtaining a good photographed image. To do.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a drive portion constituted by a movable first portion and a fixed second portion and an optical member are held, and the drive portion is provided near the center of gravity. Of the optical holding member, at least two or more supporting portions that movably support the optical holding member, and a fixed supporting member that has a positioning portion that positions the second portion of the drive portion. The support portion of the support member is provided on substantially the same plane as the first portion of the drive portion, and is provided at a substantially symmetrical position with respect to the first portion of the drive portion. The composition,
It is possible to provide an optical device that is small and stable even during operation.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a first embodiment that best represents the features of the present invention. In the figure, reference numeral 1 denotes an optical holding member for holding an optical member such as a lens.
1b, a plane groove portion 1c, and a mounting portion 1e to which a magnetic member such as a permanent magnet described later is mounted. k represents the optical axis of the optical system. Reference numeral 2 is a magnetic portion as a movable first portion that constitutes a drive portion, for example, a magnetic member such as a permanent magnet, which is magnetized in the optical axis direction and is attached to the mounting portion 1e of the optical holding member 1 with an adhesive. It is stuck due to Reference numeral 3 is a coil which is a fixed second portion which constitutes a drive unit and which generates a magnetic field by being energized. Reference numeral 4 is a ball serving as a rotating member. Reference numeral 5 is a support member which movably supports the optical holding member 1. Is. The coil 3 is fixed to the coil attachment portion 5e of the support member 5 with an adhesive or the like. The support member 5 has three V groove portions 5a, 5b for restricting the movement of the optical holding member 1,
5c is formed, and each V groove portion 5a, 5 of the support member 5 is formed.
The balls 4 are sandwiched between b and 5c, the V groove portions 1a and 1b of the optical holding member 1 and the flat surface groove 1c, respectively. Here, the groove directions of the V groove portions 1a and 1b of the optical holding member 1 and the V groove portions 5a and 5b of the support member 5 are the optical axis direction of the lens, and the two sets of the V groove portion and the ball 4 and the remaining one plane. The groove portion 1c, the V groove portion 5c of the support member 5, the plane groove portion 1c of the optical holding member 1 and the ball 4 sandwiched between the V groove portion 5c of the support member 5 in the three-dimensional direction of the optical holding member 1 with respect to the support member 5. The posture is determined, and the rolling of the ball 4 causes the optical holding member 1 to move in the lens optical axis direction. Reference numerals 6a and 6b denote position sensors for detecting the position of the optical holding member 1, one of which is held by the holding portion 1d of the optical holding member 1 and the other of which is held by the holding portion 5d of the support member 5 to detect the position of the optical holding member 1. It is detected by magnetic or optical means. For example, in the case of magnetic detection, 6a is a combination of permanent magnets, 6b is a combination of Hall elements, and in the case of optical detection, 6a has a scale with regular unevenness, and 6b has a laser emitting part and a light receiving part. And a combination of semiconductor elements. These detecting means are disclosed in
Since it is disclosed in Japanese Patent No. 344404, Japanese Patent Laid-Open No. 5-224112, etc., it will not be described in detail here. In the following description, for convenience, magnetic detection is performed, 6a is a magnet, and 6b is a Hall element. Reference numeral 7 denotes an electrical mounting board, which is connected to the coil 3 and has a hole 7a which fits into the outer shape of the supporting member 5, so that the coil 3 is fitted and positioned with respect to the supporting member 5. Reference numeral 8 is a yoke as a magnetic path forming member made of soft iron or the like having a high magnetic permeability, and a position with respect to the supporting member 5 is determined by fitting a part of the supporting member 5 in the holes 8a and 8b. And forms a magnetic circuit with the permanent magnet 2. Therefore, an attractive force is exerted between the permanent magnet 2 and the yoke 8 by the magnetic force, and the optical holding member 1 and the support member 5 fixed to each of them apply a force in the direction of holding the ball 4. Therefore, even if the optical holding member 1 is moving, the optical holding member 1 and the support member 5 are
The relationship between the ball 4 and the ball 4 is extremely stable without any play. Note that the permanent magnet 2 can be integrally formed by forming the optical holding member 1 with a plastic magnet.

Next, the assembling method will be described. 1. With respect to the support member 5, the coil 3, the hall element 6b,
The electrical mounting board 7 and the yoke 8 are respectively positioned as described above, and are stacked and fixed by an adhesive or the like. 2. The coil 3 and the position sensor 6b with respect to the electrical mounting board 7
Wiring. 3. Set the balls 4 in the V grooves 5a, 5b, 5 on the guide, respectively.
Put it on c. 4. The permanent magnets 2 and 6a are fixed to a predetermined position of the optical holding member 1 including the lens system with an adhesive or the like. 5. The optical holding member 1 is placed on the support member 5 so that the ball 4 is sandwiched between predetermined grooves.

As described above, the coil 3 for driving the optical holding member 1 in the optical axis direction, the actuator including the permanent magnet 2 and the yoke 8, the position sensor, and the ball supporting portion between the optical holding member 1 and the supporting member 5 are unidirectional. Since they can be easily assembled by stacking, the cost can be reduced by mass production using, for example, a robot.

FIG. 2 shows a sectional view perpendicular to the optical axis. The same parts as those in FIG. 1 are denoted by the same reference numerals. 21, 2
Numeral 2 is a contact point between the V groove 1a and the groove 1c and the ball 4, that is, a supporting portion. Permanent magnet 2, coil 3, yoke 8
When a current is passed through the coil 3 in the actuator configured as described above, a driving force is generated due to the interaction between the magnetic circuit and the current, which will be described later, and the optical holding member 1 moves in the optical axis direction (direction perpendicular to the paper surface). At this time, the permanent magnet 2 is fixed to the optical holding member 1, and assuming that the permanent magnet 2 is sufficiently heavy with respect to the optical holding member 1 when holding the lens,
The center of gravity of the movable portion is below the optical axis in the figure, that is, near the permanent magnet 2. If the X-axis and the Y-axis are defined in the plane perpendicular to the optical axis and the first, second, third, and fourth quadrants are clockwise from the upper right quadrant, the center of gravity is in the second and third quadrants. And the actuator including the support member 5, the permanent magnet 2, the coil 3 and the yoke 8 is arranged in the second and third quadrants which are continuous. In this way, when the center of gravity of the movable portion is off the optical axis, the portion that generates the driving force or the portion on which the driving force acts and the movable portion are supported in the same quadrant where the center of gravity exists or in two consecutive quadrants. The support part is arranged, that is, the vicinity of the permanent magnet 2 on which the driving force acts is the center of gravity of the movable part including the optical holding member 1, and is provided near the center of gravity and on both sides of the center of gravity position. Since the optical holding member 1 is supported by the supporting portions 21 and 22, it is possible to maintain a stable state even when the optical holding member 1 is driven.

In FIG. 3, a cross section of the optical holding member 1 passing through the Y axis and a cross section of passing through the ball 4 and parallel to the Y axis are shown in FIG. 3 as cross section AA and cross section BB, respectively.
The state of driving in the optical axis direction will be described.

Sections A--A (a), (b) and (c) of FIG.
And (A), (B), and (C) in the cross section B-B,
The optical holding members 1 show respective cross sections at the same position.
A magnetic path shown by a dotted line in the drawing is formed between the permanent magnet 2 and the yoke 8 in the cross section AA (b). When a current is passed through the coil 3 existing in the magnetic path between the permanent magnet 2 and the yoke 8, the optical holding member 1 is moved in the optical axis direction by the driving force generated by the interaction between the magnetic force and the current. By changing the direction of the electric current, the moving direction changes. The cross section BB (B) shows a state in which the ball 4 supports the optical holding member 1. As described above, the cross section A-A
Since the attraction force is exerted between the permanent magnet 2 and the yoke 8 by the magnetic force, the optical holding member 1 and the supporting member 5 are in close contact with each other via the ball 4 without any play, and the optical holding member 1 is in the direction of The ball 4 rotates leftward when moving in the direction A), and rotates rightward when moving in the direction C, and the optical holding member 1 and the supporting member 5 are also stable through the ball 4 without rattling. The posture of the optical holding member 1 can be held even during movement.

Further, since the optical holding member 1 moves while the ball 4 between the optical holding member 1 and the supporting member 5 rolls, the rolling friction acting between the optical holding member 1 and the supporting member 5 on the ball 4 is Compared with the sliding friction that acts on the contact portion between the guide pin and the lens holding member described in the conventional example,
It is so small that it can be ignored, and the load during lens transfer due to friction can be reduced.

FIG. 4 shows, as a second embodiment, an example in which the magnetic path is more concentrated in the coil 3 to stabilize the driving force and the magnetic path. Reference numerals 41 and 42 denote permanent magnets, which are magnetized in the direction perpendicular to the optical axis. Reference numeral 43 is a back yoke fixed to the permanent magnets 41 and 42. In such a configuration, the magnetic path has permanent magnets 41, 42 with the smallest spatial gap.
Concentrate between the lower surface of the and the yoke 8.

Next, the diaphragm device will be described with reference to FIGS. FIG. 5 is a sectional view of the diaphragm device in a direction perpendicular to the optical axis,
FIG. 6 is a cross section taken along line CC of FIG. 51 and 52 are diaphragm blades, which are driven in the directions of the arrows in the figure, respectively,
It is designed to control the opening of 3. The structure as an actuator is the permanent magnet 2, coil 3, and yoke 8 of FIG.
Which is exactly the same as the actuator of the optical holding member 1 of FIG.
b, the coils 55a and 55b, and the yoke 8.
While the lens holding means is driven in the optical axis direction, the diaphragm blades are driven in the direction perpendicular to the optical axis, so the permanent magnets 54a and 54b, the coils 55a and 55b, and the support member 56.
The object is achieved by arranging drive and support means such as etc. in a direction perpendicular to the optical axis. 7 is an electrical mounting board,
Reference numeral 8 denotes a yoke, which forms a magnetic circuit with the permanent magnet 54. Since the driving and supporting means for both diaphragm blades 51 and 52 can be said to be exactly the same as those described above, they will not be described here.

FIG. 7 schematically shows an example in which the driving and supporting means according to the present invention described above is applied to a conventional photographing optical system. The target of driving is the second lens group 101b,
The fourth lens group 101d and the diaphragm means 114.
These are supported on the substrate 7 by supporting means 70, 71 and 72, respectively, and driving means 73 and 7 on the substrate 7 are provided.
4, 75 are driven in predetermined directions. Electrical components such as coils are mounted on the board 7. t is an outer dimension of the drive unit second lens group 101b, the fourth lens group 101d, and the housing around the diaphragm unit 114 in a direction orthogonal to the optical axis. The size of the image pickup optical system can be reduced as compared with the conventional one in which the lens frame is axially supported by the guide pins on both sides of the lens.

[0017]

As described above, according to the present invention, the driving portion constituted by the movable first portion and the fixed second portion and the optical member are held, and in the vicinity of the center of gravity position. An optical holding member having a first portion of the drive portion, at least two or more support portions for movably supporting the optical holding member, and a fixed support member having a positioning portion for positioning the second portion of the drive portion. And the support portion of the support member is provided on substantially the same plane as the first portion of the drive portion, and is provided at a substantially symmetrical position with respect to the first portion of the drive portion. With a simple structure, it can be downsized, and at the same time, it can be positioned at the approximate center of gravity of the optical holding member where the driving part or the driven part moves, and the optical holding member can be supported at an ideal position.
It is possible to provide an optical device that is stable even during operation.

[Brief description of drawings]

FIG. 1 is an assembly configuration diagram of an optical device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an optical device according to the present invention in a direction perpendicular to an optical axis.

FIG. 3 is a sectional view of an optical device according to the present invention in the optical axis direction.

FIG. 4 is a diagram of an optical device according to a second embodiment.

FIG. 5 is a front view of a diaphragm device according to the present invention.

FIG. 6 is a sectional view of a diaphragm device according to the present invention.

FIG. 7 is a schematic diagram of an optical device according to the present invention.

FIG. 8 is a sectional view of an optical device according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical holding member 2 Permanent magnet 3 Coil 4 Ball 5 Supporting members 6a, 6b Position sensor 7 Electrical mounting substrate 8 Yoke

Claims (3)

[Claims] 1. A drive section composed of a movable first section and a second section fixed to the movable section, and a first section of the drive section for holding an optical member and near the center of gravity. An optical holding member, at least two or more supporting portions that movably support the optical holding member, and a fixed supporting member that has a positioning portion that positions the second portion of the drive portion. The optical member, wherein the support portion of the member is provided on substantially the same plane as the first portion of the drive portion, and is provided at a substantially symmetrical position with respect to the first portion of the drive portion. machine. 2. A coil for generating a magnetic field by energizing the second portion of the drive unit, wherein the first portion of the drive unit is generated in the coil by a magnetically acting force. The optical device according to claim 1, wherein the optical device is a permanent magnet member that is moved by a magnetic field. 3. An optical holding member which holds an optical member and which has a driven portion, a support portion which movably supports the optical holding member, and a drive portion which gives a driving force to the driven portion. One supporting member and the driving unit are orthogonal to the optical axis direction of the optical member, and one quadrant or continuous including the center of gravity of the optical holding member on a plane intersecting the optical axis. The optical device is included in the two quadrants, and the driving unit, the driven unit, and the supporting unit are arranged so as to overlap in one direction on the plane.