WO1984004991A1

WO1984004991A1 - Apparatus for adjusting optical axis of optical pickup

Info

Publication number: WO1984004991A1
Application number: PCT/JP1984/000276
Authority: WO
Inventors: Masashi Ito; Toshiki Matsuno; Hiroyuki Nakamura; Hiroshi Yasuda
Original assignee: Matsushita Electric Ind Co Ltd
Priority date: 1983-06-03
Filing date: 1984-05-29
Publication date: 1984-12-20
Also published as: JPH0462132B2; JPS59223953A

Abstract

A retainer member, such as an objective lens driver (2) which holds an objective lens (1), is slid around spherical surfaces (10, 11) by the rotation of screws (6a, 6b), in order to change the angle of inclination of the objective lens (1), thereby adjusting the angle of inclination of the optical axis of the objective lens (1). Thus it is possible to adjust the optical axis in all directions with a simple operation. Moreover, it is not necessary to readjust the height of the objective lens (1), since the position of a light spot does not change.

Description

Specification

Title of invention

Optical axis adjustment device for optical big

Technical field

The present invention relates to an optical axis adjusting device for an optical bicub used in a reproducing apparatus of a type that optically reads information by projecting an optical spot onto a disk-shaped recording medium.

Background art

In general, in order to read information accurately with this type of optical disc playback device, it is necessary to maximize the performance of the objective lens and to narrow the optical slot as small as possible. To do this, the tilt of the objective lens must be close to zero. The following describes the conventional optical axis adjustment device of the optical big-bub o o

Fig. 1 shows a conventional optical pickup.], 1 is the objective lens, 2 is the objective lens 1, and this objective lens ^{1 is used} for tracking and focusing. objective lenses driving device for驟動to, 3 optical pro click the objective lenses driving device 2 is ^{mounted, 4 a ,. 4 b, 4} C, 4 d is the objective lenses operated device 2 and the optical Bro Tsu A coil panel 5a, 5b, 5c, 5d inserted between the holes 3 for elastically holding the objective lens driving device 1 is provided at the bottom of the objective lens driving device 2. Screw holes 6a, 6b, 6σ, 6d are screwed into screw holes 5a, 5b, 5c, 5d, and are used to compress coil panels 4, 4b, Ac, 4d. is there.

Fig. 2 shows the adjustment method of the conventional optical axis adjustment device for optical pickup.

O PI 3, T a and 7 b are the center of the objective lens, 8 a and 8 b are the respective optical axes, and 9 a and 9 b are the respective optical slots. O

In this conventional configuration, turning ^two of the four screws in Fig. 1 to adjust the tilt of the objective lens 1, the center 7a of the objective lens becomes as shown in Fig. 2. Moves to 7b, along with which the optical axis moves from Sa to 8b, the position of the optical spot and lit also moves from 9a to 9b, and the objective lens ¹ faces this objective lens ¹ . There is a defect that the distance between the disk and the disk rotating at the position changes. O To correct this, change the distance between the disk and the objective lens ¹ by changing the distance between the disk and the four screws 4a and 4b. , 4 c, 4 d are readjusted by turning them all by the same amount, and the change in the position of the optical slot is compared with the entire optical pickup, that is, the objective lens drive 2. It was necessary to perform readjustment by moving and adjusting the entirety of the optical block 3 and the integrated unit. There is a problem that it takes extra time to adjust the tilt of the object lens o

Disclosure of the invention

Accordingly, an object of the present invention is to solve the conventional problems as described above and to provide an optical pick-up optical axis adjusting device that can easily and quickly adjust the tilt of an objective lens. I do.

That is, according to the present invention, the holding member of the objective lens is inclined with respect to ^one point inside the objective lens, in particular, a spherical surface having a center at the center of the principal plane of the lens effect of the objective lens, and the spherical surface and the spherical surface are inclined. Or because a sphere and an arc or ^three or more points on the same sphere slip? , Objective lens

OMPI This is to adjust the inclination of the noise. In this case, since the position of the optical slot does not change, readjustment is not required. Also, two screw holes for tilt adjustment are arranged at 90 degrees to the center of the spherical surface, and if the position of the coil panel is devised, the spherical surface will be smooth and the adjustment range will be fine. Wide, efficient and quick tilt adjustment. Furthermore, since the spherical surface is fitted into the spherical surface, the height and position of the objective lens driving device are fixed.], And assembling jigs are required at the time of assembly, so that the time for assembly and adjustment can be greatly reduced. There o

Brief description of drawings

FIG. 1 is an exploded perspective view of a conventional optical axis adjusting device for an optical big-bub, FIG. 2 is a side view for explaining the operation thereof, and FIG.

—An exploded perspective view of the optical axis adjusting device of the optical probe according to the embodiment, and FIG. 4 is a side view for explaining the operation.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. ³ and ⁴ . ³ and ⁴ , the same components as those in FIGS. ¹ and 2 are denoted by the same reference numerals. O FIG. ³ shows an optical axis adjusting device for an optical big-bub according to an embodiment of the present invention. It shows. In FIG. 3, reference numeral 1 denotes an objective lens, ² denotes an objective lens that holds the objective lens ¹ , and drives the objective lens ^{1 in} tracking and focusing directions. and o, a convex spherical surface formed or fixed to the bottom of the base of the objective lens drive device 2. The spherical surface ¹ O is constituted by a part of a hemispherical surface.

3 is an optical block to which the objective lens driving device ² is mounted, ^{1 1}

OMPI_ Is a concave spherical surface formed or fixed on the upper surface of the optical block 3. This spherical surface 1 1 is also composed of a part of a hemispherical surface. 4 a, 4 b, 12 a, 12 b are coilpanes, 5 a, 5 b, 5 c, 5 d are screw holes, of which screw holes 5 a, 5 b have an angle with the sphere center. O 6a, 6b, 6c, 6d are screws o

In the above configuration, the convex spherical surface ¹設け provided on the objective lens 2 is fitted into the concave spherical surface 11 of the optical block 3, and the objective lens driving device 2 changes the spherical surface 1 O, 1 1 The optical block 3 is attached so that it can rotate freely at the center of the lens. The coil panels 12a and 12b are compressed by the screws 6c and 6d screwed into the screw holes 5c and 5d, and the objective lens drive 2 is moved toward the optical block 3 with a constant force. The ₀ coil panels 4a and 4b that are being pulled push up the objective lens driving device 2 so that the spherical surface 1O and the spherical surface 11 move smoothly without digging, and the tilt adjustment range is increased. Screws 6a and 6b are screws for adjusting the tilt of the objective lens! ), The inclination of the objective lens 1 integrated with the objective lens driving device ² is adjusted by turning these ^two screws.

According to this embodiment, the spherical ¹ 0 as shown in FIG. 4, ^{1 1} in the main plane of the lenses effect of the objective lenses 1, than centered at 7, objective lenses in all directions Even if 1 is tilted, the position of the optical spot 変化 does not change, and the distance between the objective lens and the disc changes as in the conventional example! ), The position of the optical slot has shifted. As a result, the tilt of the objective lens can be quickly adjusted to zero.

OMPI Dramatically reduced. Further, in the adjustment, the objective lens 1 can be tilted in any direction simply by turning the two screws 6a and 6b sequentially, so that the operation is very simple. Also to receive a convex spherical surface 1 O concave spherical surface 1 ^1, this alone objective lenses

5 Position and height of drive unit 2 are determined. O Therefore, a jig for determining the position and height is required in assembly. In actual practice, it is only necessary to change the shape of the bottom of the base of the objective lens driving device 2 and the shape of the top of the optical block 3, and a spherical surface can be formed at the same time during molding. It's really good. io In this embodiment, the spherical surface and the spherical surface are all used. However, a cylindrical convex portion is formed at the bottom of the objective lens driving device- ² , and this convex portion is formed at the upper portion of the optical block 3. It may be fitted into the concave spherical surface provided in the optical block 3, or a circular concave portion may be provided in the upper part of the optical block 3 and the convex spherical surface provided in the bottom portion of the objective lens moving device may be fitted into this concave portion. 5 Good. That is, the spherical surface only needs to be at one of the bottom of the objective lens driving device and the upper portion of the optical block.

Also, no matter how small the area of the spherical surface is, the same effect can be obtained, so that one spherical surface may be composed of three or more points.

In the embodiment, two screws ⁶ c and 6 d on the non-adjustment side and two coil panels 0 12 a and 12 b are provided. However, one screw is provided near the center of the screws 6 c and 6 d. It is also possible to simply provide a telephone and a telephone.

Further, even when the objective lens is composed of a combination of a plurality of lenses, the same effect can be obtained if the center of the spherical surface is located at the center of the principal plane of the lens effect.

5 Industrial applicability In the present invention, the optical axis of the objective lens is adjusted using a spherical surface. Therefore, the tilt of the objective lens can be easily and quickly adjusted, and the height of the objective lens can be adjusted when the tilt is adjusted. The height and position of the optical robot do not change, so there is no need to readjust the height and position as before. Furthermore, since the concave and convex spherical surfaces receive other members, the height and position of the objective lens movement device are determined, so that a special mounting jig for determining the height and position is not required. In addition, the tilt can be adjusted smoothly over a wide range by devising the position of the coil panel. Furthermore, if two adjusting screws are arranged so that the degree of SO is set to the center of the sphere, there is an advantage that the tilt can be adjusted efficiently. As a result, the workability of adjusting the tilt of the objective lens is greatly improved, the man-hours for assembly and adjustment are greatly reduced, and production costs can be reduced.

Claims

The scope of the claims

1. In an optical microscope in which the optical axis of the objective lens can be tilted in all directions, the holding member that holds the objective lens has a center at the center of the principal plane of the lens effect of the objective lens. Along the sphere

5 Optical pick-up optical axis adjustment device characterized by being configured to incline

2. In claim 1, the objective lens driving device for holding the objective lens and driving the objective lens in the tracking and focusing directions, and the objective lens driving device. An optical io-block to be in contact with the objective lens driving device and the optical block, wherein at least one of the mutually contacting surfaces of the objective lens driving device and the optical block has a spherical surface. Optical axis adjustment device.

3. The objective lens according to claim ¹ , wherein the objective lens, an objective lens driving device that holds the objective lens, and drives the objective lens in five directions of tracking and focusing. An optical block that is in contact with the objective lens moving device, and a spherical surface that is provided on at least one of the mutually contacting surfaces of the objective lens driving device and the optical block; ^Three or more screw holes provided in the objective lens driving device, ^three or more screws that penetrate the optical block and are screwed into the screw holes, and ^{two of the} screws Fitted, front

The two coil panels, which are compressed and inserted between the objective lens excursion device and the optical block, are inserted into the remaining screws among the screws, and between the screw head and the optical block. An optical axis adjusting device for an optical big head, comprising a compression-inserted coil panel.

5 o

U OMPI

^ W1PO,

4. A big tube according to claim 3, characterized in that two of the screw holes are arranged at a position where the angle between these screw holes and the center of the spherical surface is 90 degrees. Optical axis adjustment device.