JPH0438727A - Dust sticking preventing mechanism for objective lens in optical pickup device - Google Patents

Abstract

PURPOSE:To avoid the inform of a wind caused by the rotation of a disk into a through hole, and to prevent dust from sticking on an objective lens by providing a lid body with a windbreak member on its outwardly facing part in the diametric direction of the through hole. CONSTITUTION:The windbreak member 15 to constitute an objective lens dust sticking preventing mechanism is provided on the opposed surface 13a of the lid body 13. The member 15 is disposed at the side of the through hole 13b from which the wind caused by the rotation of the disk 11 flows into the lid body 13. Besides, the member 15 is formed into a streamline shape whose upper surface 15a is inclined upgrade as approaching to the hole 13b, and simultaneously, it is shaped so that its end surface 15b is lowered vertically at the vicinity of the hole 13b. In such constitution, after the wind 14 is raised once by the member 15, it flows along the member 15, and passes through the hole 13b, and is lowered without flowing into the hole 13b. Thus, the inflow of the wind caused at the time of the rotation of the disk into the through hole of the lid body can be avoided, and the sticking of the dust to the objective lens can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applied to an optical pick amplifier device equipped with an objective lens, for example, a magneto-optical disk device, an optical disk device, or a video disk device. The present invention relates to an objective lens dust prevention mechanism of an optical pickup device used for dustproofing the objective lens.

[Conventional technology]

Conventionally, an optical pickup device is equipped with an optical pickup and writes, reproduces, or erases information using the optical pickup, as shown in FIG. 5(a).
As shown in (b), there is an objective lens 52 for irradiating the disk 51 with a beam from a laser (not shown) that is a light source, and a beam irradiated from the objective lens 52 is made to follow the pits of the disk 51. An objective lens driving means (not shown) for this purpose is disposed below the disk 51.

The objective lens 52 and the objective lens driving means are usually
The cover 153 is covered with a gear ζ so as to be protected from external disturbances, and the opposing surfaces 53a and J- of the cover 153 that face the disk 51 are provided with a beam that is irradiated from the objective lens 52 onto the disk 5j. Through hole 5 for passing through the beam
3b is drilled.

[Problem to be solved by the invention]

However, in the conventional structure described above, the opposing surface 53 of the lid body 53
Since the through hole 53b is formed on the lens a, the surface 52a of the objective lens 52 facing the disk 51 always faces the outside. Therefore, the wind 54 generated by the rotation of the disk 51 in the F direction blows dust away from the objective lens 5.
As a result, the objective lens 52
The cross section of the beam passing through the center will no longer be a symmetrical circle, and there is a risk of incorrect servoing. In addition, the objective lens 52
If there is a large amount of dust attached to the objective lens 52,
The problem is that the amount of light passing through the sensor is significantly reduced, resulting in a drop in the detected signal level.

[Means to solve the problem]

In order to solve the above problems, the objective lens dust adhesion prevention mechanism of the optical big amplifier device according to the present invention is provided with an objective lens for irradiating beams from a light source onto a disk as a recording medium. , objective lens driving means for causing the beam irradiated from the objective lens to the disk to follow the pits of the disk, and -1- the objective lens and the objective L.
an optical type comprising a cover body covering a lens driver 1 and a cover body having a through hole drilled on an opposing surface facing the disk for penetrating the beam J that is irradiated from the objective lens to the disk; The following measures are taken in the pink-up device.

That is, the lid body has a radially outward portion of the through hole,
A windshield member is provided.

[For production]

According to the above configuration, the lid body is provided with a windshield member on the outward side in the radial direction of the through hole, so that when the optical pickup device is operated, the wind generated by the rotation of the disk is directed into the through hole. It is possible to avoid the inflow of Additionally, it is possible to avoid dust from adhering to the objective lens, and it is possible to reliably irradiate the disk with the beam from the light source in a prescribed state.

[Embodiment 1] An embodiment of the present invention will be described below with reference to FIGS. 1(a) and 2(b).

As shown in FIG. 2, the optical pick amplifier device according to this embodiment includes a laser 21 as a light source, an optical system 22, an objective lens 12, and a photodiode 23. Depending on the device, disk 11
When reproducing the recorded signal, the beam emitted from the laser 21 passes through the optical system 22 and enters the objective lens I2. Then, the objective lens 12 focuses the beam on the bit of the disk 11 to 1 μm, and after the focused beam contains the recording signal of the disk 11, it passes through the objective lens 12 again and enters the optical system 22. It is incident. The beam incident on the optical system 22 is reflected by the optical system 22 and incident on the photodiode 23, and the photodiode 23 detects the beam containing the recording signal as an electrical signal.

The objective lens 12 is disposed below the disk 1, as shown in FIGS. It is designed to follow.

Furthermore, the objective lens 12 and the objective lens drive means are covered by a lid 13 to be protected from external disturbances.

2. The objective lens 13 has through holes 13b formed in the opposing surface 13a-h facing the disk 11 in order to pass the beam irradiated from the objective lens 12 to the disk 11. surface 1 facing the disk 11 of
2a is always facing the outside.

Further, on the facing surface 13a1 of the lid 13, there is provided a windshield part 1 constituting the objective lens dust adhesion prevention mechanism of the present invention.
5 is provided.

In the windshield member 15, the wind 14 generated by the rotation of the disk 11 in the E direction with respect to the through hole 1.3b is attached to the cover]
It is disposed on the opposing surface 13a on the side flowing into 3. In addition, the top surface of the windshield member 15 shown in "2" 5a is connected to the through hole 13.
As the end face 1, 5b approaches the through hole 13b, it takes on a streamlined shape that slopes upward, and the end face 1, 5b has a shape that descends perpendicularly to the opposing face 13a near the through hole 13b.

In the configuration described in Section 2, the wind 14 generated when the disk 11 is rotated in the E direction by this optical pink-up device is once lifted by the windshield member 15, as shown in FIG. 1(b), and then It flows along the windshield member 15, and then passes through the through hole 13b and descends without flowing into the through hole 13b.

[Embodiment 2] The optical pickup device according to this embodiment is formed in the same manner as the optical pink amplifier device of the first embodiment except for the windshield member that constitutes the objective lens dust adhesion prevention mechanism.

The windshield member 35 according to the second embodiment is shown in FIGS.
), similar to the windshield member 15 of the first embodiment.
While the second surface 35a has a streamlined shape, the width W is formed wider than that of the windshield member 15 of the first embodiment, and the lid body 1
The through hole 13b of No. 3 is surrounded by a U-shape.

In the above configuration, the wind 34 generated by the rotation of the disk 11 in the E direction is once lifted by the windshield member 35, flows along the windshield member 35, and then flows , it passes through the through hole 13b and descends without flowing into the through hole 13b. The windshield member 35 of the second embodiment has a U-shaped shape that surrounds the through hole 13b, thereby preventing the wind 34 from flowing into the through hole 13b more effectively than the first example. This is to ensure that.

[Embodiment 3] The optical pickup device according to this embodiment is formed in the same manner as the optical pickup device of the first embodiment except for the windshield member that constitutes the objective lens dust adhesion prevention mechanism.

The windshield member 45 according to the third embodiment is shown in FIGS.
), it has a U-shaped cross section and a convex portion 45.
It is disposed on the opposing surface 13a so as to surround the through hole 13b in a streamlined shape, with the through hole 13b being opposed to the through hole 13b.

2, the wind 44 generated by the rotation of the disk 11 in the E direction is prevented from flowing into the through hole 13b by the windshield member 45, as shown in FIG. 4(C).
It flows along the windshield member 45, dividing into left and right sides. still,
The windshield member 45 having a U-shaped cross section of the third embodiment can more effectively prevent the wind 44 from flowing into the through hole L3b by surrounding the through hole 13b in a streamlined manner compared to the second example. This is to ensure that.

[Effects of the Invention] As described below, in the objective lens dust adhesion prevention mechanism of the optical pickup device according to the present invention, the lid body is provided with a windshield member on the outward part in the radial direction of the through hole. It is the composition.

Thereby, it is possible to prevent the wind generated when the disk rotates from flowing into the through hole of the lid. Therefore, it is possible to prevent dust from adhering to the objective lens, and as a result, the beam can be reliably irradiated from the objective lens to the disk in a prescribed state. In addition, by providing a windshield (A) on the lid body as a mechanism for preventing dust from adhering to the objective lens, it is possible to easily prevent dust from adhering to the objective lens without reducing the function of the objective lens drive means. be effective.

[Brief explanation of the drawing]

FIGS. 1(a) and 2(b) and 2 show a first embodiment of the present invention. FIG. 1(a) is a perspective view showing an optical pickup device equipped with a windshield member. FIG. 1(b) is a sectional view taken along the line AA in FIG. 1(a). FIG. 2 is a schematic configuration diagram showing an optical pink-up device. FIG. 3(a) is a perspective view showing an optical pink-up device equipped with a windshield member according to a second embodiment. FIG. 3(b) is a sectional view taken along the line BB in FIG. 3(a). FIG. 4(a) is an enlarged perspective view showing the windshield member of the third embodiment. FIG. 4(b) is a perspective view showing an optical pickup device equipped with a windshield member according to a third embodiment. FIG. 4(c) is a sectional view taken along the line CC in FIG. 4(b). FIGS. 5(a) and 5(b) show conventional examples. FIG. 5(a) is a perspective view showing the optical pickup device. FIG. 5(b) is a sectional view taken along the line I)-D in FIG. 5(a). 11 is a disk, 12 is an objective lens, 13 is a lid body, 13
13b is a through hole, 15 is a windshield member, and 21 is a laser (light source).

Claims (1)

[Claims] 1. An objective lens for irradiating a beam from a light source onto a disk as a recording medium, and an objective lens driving means for causing the beam irradiated from this objective lens to the disk to follow the pits of the disk. and a lid body that covers the objective lens and the objective lens drive means, and has a through hole bored on the opposing surface facing the disk, through which the beam irradiated from the objective lens to the disk passes. An objective lens dust adhesion prevention mechanism for an optical pickup device, wherein the lid body is provided with a windshield member on a radially outward portion of the through hole.