JPH05225596A - Dustproof structure for lens actuator - Google Patents

Abstract

PURPOSE:To improve the reliability of an optical system recording and reproducing information by interrupting perfectly dust entering into the inside of an optical head on the dustproof structure of a lens actuator used for an optical disk device exchanging a recording medium. CONSTITUTION:A thin and transparent optical plate 16 through which a laser beam 4a outgoing from the objective lens 4-2 of the optical head transmits is placed between with a disk medium and an light emitting hole 4-1a provided on the case 14-1 of the optical head is sealed through a sealing member 17 whose central part formed with a wave shaped fold in a concentric circular shape is movable in a free direction by a minute size. Then the optical plate 16 is constituted so as to be moved interlocking with the objective lens 4-2 by an interlocking member 18 erected on the peripheral end surface of flue objective lens 4-2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dustproof structure for a lens actuator used in various optical disk devices having exchangeable storage media.

Recently, in an optical disk device in which a recording medium for recording / reproducing computer information is replaceable, dust easily adheres to the optical disk medium or the optical head during recording / reproducing, and a recording / reproducing error easily occurs. In order to remove the dust, conventionally, a medium cleaner and a lens cleaner for wiping off dust and dust adhering to the lens are distributed to the user to take countermeasures.

However, an optical component such as a prism is disposed inside the optical head, and dust adhering to the back surface of the objective lens (on the side opposite to the optical disk medium) and the optical component is practically hardly cleaned. A dust-proof structure of a lens actuator that can prevent dust from entering the optical head is required because it is possible and leads to a decrease in reliability of the optical disc device.

[0004]

2. Description of the Related Art Optical head 4 which has been widely used in the past
Is a lens holding member 4-3 having an objective lens 4-2 fixed to the information recording surface of a disk medium rotating at a high speed as shown in FIG. The objective lens 4- is moved to the information recording position of the disk medium by moving in the (focus direction) and the tracking direction.
The objective lens 4-2 is supported by a lens actuator 4-4 that accurately follows 2 so that the objective lens 4-2 is approximately flush with the light exit hole 4-1a formed in the upper part of the case 4-1 made of synthetic resin, for example. The optical component 4-5 such as a prism necessary for irradiating the information recording surface of the disk medium with the laser beam 4a is provided inside the case 4-1.

In the optical disk device 1 having the optical head 4, as shown in FIG. 4, a disk medium 3 which is chucked by a disk rotation drive section 2 provided inside a housing 1-1 and rotates at a high speed. Laser light 4a on the information recording surface of
And the direction of the disk rotation drive unit 2, that is, the disk medium 3 by the access mechanism 5.
The optical head 4 is disposed so as to swing in the radial direction.

[0006]

The problem with the conventional optical head described above is that the cleaning of the objective lens 4-2 and the optical components 4-5 such as the prism should be carried out periodically or when necessary. However, the light output hole 4- of Case 4-1
Dust adhering to the rear surface of the objective lens 4-2 exposed from 1a, that is, the surface opposite to the disk medium 3 and optical components 4-5 such as prisms arranged inside is cleaned from the outside of the case 4-1. However, it is almost impossible to do so, and the function of each device is lowered, so that the reliability of the optical disk device is lowered.

Further, the working distance between the objective lens 4-2 and the disk medium 3 is about 1 mm, and there is a problem that it is impossible to install an independent optical window during the working distance. .

In view of the above problems, the present invention can improve the reliability of the optical system for recording / reproducing information by completely blocking the dust invading the inside of the optical head with a simple structure. It is intended to provide a dustproof structure for a lens actuator.

[0009]

According to the present invention, as shown in FIG. 1, a thin and transparent optical plate 16 which transmits a laser beam 4a emitted from an objective lens 4-2 of an optical head 14 is provided. -2 and the disk medium, the optical head is provided with a corrugated fold 17a formed in a concentric circular shape and a sealing member 17 capable of finely moving a central portion in a free direction.
The light output hole 4-1a provided in the case 4-1 of 14 is sealed, and the optical plate 16 is linked with the objective lens 4-2 by the interlocking member 18 standing on the peripheral end surface of the objective lens 4-2. Configure to be mobile.

[0010]

In the present invention, as shown in FIG. 2 (a), the optical head is
Since the light exit hole 4-1a of the laser light 4a provided in the case 4-1 of 14 is sealed by the optical plate 16 and the sealing member 17, it is possible to completely block the intrusion of dust into the optical head 14. At the same time, since the optical plate 16 and the lens holding member 4-3 to which the objective lens 4-2 is fixed are connected by the interlocking member 18, it is interlocked with the vertical movement of the objective lens 4-2 by the lens actuator 4-4. Since the optical plate 16 is moved, the distance between the objective lens 4-2 and the disk medium 3 is always substantially constant, and the reliability of the optical system for recording / reproducing information on / from the disk medium can be improved. Become.

[0011]

Embodiments of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a partially cutaway perspective view showing a dustproof structure of a lens actuator according to the present embodiment, and FIG. 2 is a sectional view of a moving mechanism of an optical plate according to the present embodiment. In FIG. Although indicated with symbols, the other 16 are optical plates interposed between the objective lens of the optical head and the disk medium, 17 is a sealing member for fixing the optical plate and sealing the case of the optical head, and 18 is the optical plate Is an interlocking member that interlocks with the lens actuator.

As shown in FIG. 1, the optical plate 16 is a transparent thin plate through which the laser beam 4a emitted from the objective lens 4-2 is transmitted, for example, an optical glass plate having a thickness of about 0.1 mm or a transparent polycarbonate. Than a synthetic resin plate
The case 4-1 of the optical head 14 is formed into a disc shape with a diameter slightly smaller than the light output hole 4-1a formed on the upper surface of the optical head 14 and is subjected to optical polishing to form parallel surfaces on both sides and an antireflection film is applied. ing.

The sealing member 17 has an inner diameter slightly smaller than the outer diameter of the optical plate 16 as shown in FIG.
4-1 Form a synthetic rubber such as silicon resin or a cloth impregnated with synthetic resin with a slightly larger outer diameter than the light output hole 4-1a formed on the top surface, and if the outer circumference is fixed, the inner diameter edge is free. A fold 17a having a corrugated cross section is formed in a concentric shape so that it can be moved by a minute dimension in the direction.

As shown in FIG. 2 (b), the interlocking member 18 has a predetermined diameter and a hemispherical tip with a small diameter that can be erected on the peripheral end surface of the objective lens 4-2 fixed to the lens holding member 14-3. The length is molded from a wear resistant material with lubricity such as carbon, synthetic resin impregnated with lubricating oil, ceramic or metal material.

The dust-proof structure of the lens actuator using the above member is an objective lens 4 which fixes the laser beam 4a to the information recording surface of the disk medium 3 by being fixed to the holding member 14-3 as shown in FIG. 2 (a). -A plurality of interlocking members on the peripheral edge surface of -2
18 is provided vertically, and as shown in FIG.
-3 is supported by the lens actuator 4-4, so that the tip of the interlocking member 18 is located at the upper part of the case 4-1.
The optical component 4-5 such as a prism is provided so as to be installed in the same plane as 1a.

Then, as shown in FIG. 2 (a), the optical plate 16 is adhered to the inner peripheral edge of the sealing member 17, and the outer peripheral edge thereof is aligned with the peripheral edge of the light exit hole 4-1a formed in the upper portion of the case 4-1. Adhesive, the inner diameter edge of the sealing member 17 the objective lens
An optical head that moves the optical plate 16 by interlocking with the vertical movement and access movement of the objective lens 4-2 by the lens actuator 4-4 by contacting with the tip of the interlocking member 18 vertically provided on the peripheral end surface of 4-2. Are building 14.

As a result, the light exit hole 4-1a, which is formed in the upper part of the case 4-1 and emits the laser beam 4a from the objective lens 4-2, is sealed by the optical plate 16 and the sealing member 17, so that the optical head 14 It is possible to completely block the dust that enters the inside, and it is possible to improve the reliability of the optical system that records and reproduces information.

[0018]

As is apparent from the above description, according to the present invention, the reliability of the optical system for recording / reproducing information by completely blocking the dust invading the inside of the optical head with a very simple structure can be obtained. It is possible to provide a dust-proof structure for a lens actuator, which has advantages such as improvement, and which can be expected to have a remarkable economic effect and reliability improvement effect.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a dustproof structure of a lens actuator according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a moving mechanism of the optical plate according to the present embodiment.

FIG. 3 is a partially cutaway perspective view showing a conventional optical head.

FIG. 4 is a schematic perspective view showing a conventional optical disc device.

[Explanation of symbols]

3 is a disk medium, 4a is a laser beam, 4-1 is a case, 4-1a is a light exit hole, 4-2 is an objective lens, 4-4 is a lens actuator, 4-5 is an optical part, 14 is an optical head, 14 -3 is a lens holding member, 16 is an optical plate, 17 is a sealing member, 17a is a fold, 18 is an interlocking member,

Claims (2)

[Claims] 1. A thin and transparent disc mounted between a disc medium (3) and an objective lens (4-2) arranged in an optical head (14) of an optical disc device so as to be freely movable in the optical axis direction. Optical plate (16), and the optical plate
A dust-proof structure for a lens actuator, characterized in that the optical head (14) has a complete dust-proof structure by means of (16) and a sealing member (17). 2. The lens actuator according to claim 1, wherein the optical plate (16) is connected to a driving force of the objective lens (4-2) by an interlocking member (18) in order to move the optical plate (16). Dustproof structure.