JPH0426975Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an optical pickup device, particularly to the shape of an outer box for housing optical means.

[Conventional technology]

FIG. 4 is a side sectional view showing a conventional embodiment. In the figure, 1 is a plate made of metal as a bottom wall, 2 is a holder, and 3 is a lens mounting hole (not shown) of the holder 2. ) is an objective lens as an optical means attached to the

Dampers 4 are provided on the left and right sides of the holder 2 to hold the holder 2, and are attached to the plate 1. The holder 2 is movable by the damper 4, and by driving the holder 2 by a driving means (not shown), the position of the objective lens 3 can be adjusted, and focus control and tracking control can be performed.
5a is an outer box for optical pickup with a top wall of 5m and a side wall of 5m.
The top wall 5m has a window 5f through which the optical axis of the objective lens 3 passes, and is molded with a flat top surface. In this case, the plate 1 is fitted to the lower opening side of the side wall 5l, thereby forming a hollow outer box 5a, and the plate 1, the holder 2,
It protects a vibrator assembly composed of an objective lens 3 and a damper 4.

6 is an optical pickup base, and 7 and 8 are screws for attaching the plate 1 to the base 6. Further, by turning the screws 7 and 8 left and right, the outer case 5a can be turned so that the angle of the top wall 5m of the outer case 5l with respect to the disk 9 as an optical recording medium can be changed.
This constitutes an angle adjustment mechanism T that can tilt the angle. A indicates the mounting surface for the player, and L indicates the distance between the top wall 5m and the disc 9.

Next, the effect will be explained. The light emitted through the objective lens 3 passes through the window 5f to the optical disk 9.
The objective lens 3 receives this reflected light and sends it to a light processing means (not shown), where a signal is reproduced.

Due to variations in accuracy of the objective lens mounting surface of the holder 2, the player mounting surface A, etc., the optical axis of the objective lens 3 may be tilted as shown in C. Therefore, it is necessary to adjust the inclination of the optical axis to the normal state D so that the light beam is accurately focused on the signal portion on the surface of the disk 9 rotating at high speed. The optical axis is adjusted by tilting the vibrator assembly by rotating screws 7 and 8, which serve as angle adjustment mechanisms, attached to the plate 1 and the optical pickup base 6 to the left and right. In this example, screw 7
The outer box 5a is inclined toward the disk 9 with the side as the center.

In FIG. 3, a shows the moving distance of the upper surface of the ceiling wall 5m before and after the inclination adjustment, and M shows the width of the outer box.

Here, a rough calculation is performed. The calculation formula is a=
Msinθ becomes. Now M is 30mm, θ (tilt angle) is 1°
When calculated as follows, a=0.52mm.

[Problem that the invention attempts to solve]

However, when the vibrator assembly is tilted,
Since the distance L between the disk 9 and the top surface of the outer box 5a is about 2 mm, there is a problem that the top surface of the outer box 5a and the disk 9 come into contact when considering assembly accuracy and surface runout of the disk.

This idea was made to solve the problems mentioned above, and it is an optical system that can prevent the outer case from touching the disk and damaging the disk and optical pickup even when the optical axis tilt is adjusted. The purpose is to obtain a pick-up device.

[Means for solving problems]

In the optical pickup device according to this invention, the height of the outer circumferential portion of the top wall of the outer box that should be close to the optical recording medium is gradually lower than that of the central portion of the top wall.

[Effect]

Even if the outer box is tilted, the height of the outer periphery of the top wall is low, so it is difficult to hit the disk.

[Example of idea]

An embodiment of this invention will be described below with reference to FIGS. 1 and 2. In FIGS. 1 and 2, the same parts as in FIG. 3 are designated by the same reference numerals. In each figure,
1-4, 6-11, and A, C, D, L, M,
is exactly the same as the conventional one mentioned above. 5b
indicates an outer box in which the top wall 5m is formed into an arc shape so that the part W closest to the disk 9 on the outer circumference of the top wall 5m and the opposite side Y are gradually lower than the center side, and b shows the case before adjusting the inclination. This shows the distance traveled after doing this.

N indicates the height of the side of the outer box, and P indicates the height of the center of the outer box.

In the outer box 5b whose upper surface of the top wall 5m is formed in an arc shape as described above, it is obvious that N is smaller than P, so even if it is tilted, b is very small.

Here, a rough calculation of b is performed. The calculation formula is b=
Msinθ−(P−N). To compare with the conventional product, M is 30mm, θ (tilt angle) is 1°, and the radius of curvature is 300mm.
Then, (P-N) is 0.38, so b=
It becomes 0.14.

Note that the present invention is not limited to making the top wall 5m arc-shaped, but as shown in FIG. Of course, it may be formed into a spherical shape with the entire outer periphery gradually becoming lower.

[Effect of idea]

As described above, according to this invention, by forming at least the part of the outer periphery of the top wall of the outer box that is closest to the disk to be gradually lower than the center side, it is possible to maintain a sufficient distance between the disk and the outer case. This has the effect of preventing damage to the disk and optical pickup.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an optical pickup device according to an embodiment of this invention, FIG. 2 is a perspective view of an outer box constituting the optical pickup device of this invention, and FIG. 3 is a side view showing another embodiment. , FIG. 4 is a side sectional view showing a conventional embodiment. 1 is a plate, 2 is a holder, 3 is an objective lens, 4 is a damper, 5b
is the outer box, 5m is the top wall, 6 is the optical pickup base, 7 and 8 are screws, 9 is the disk, and T is the angle adjustment mechanism. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of utility model registration request] An outer box comprising a top wall facing an optical recording medium and having a window, a side wall, and a bottom wall, and an optical system housed in the outer box and having an optical axis extending toward the optical recording medium through the window. and an angle adjustment mechanism that adjusts the angle of the outer box so that the angle of inclination of the top wall with respect to the optical recording medium is changed, based on the angle adjustment of the outer box, the top wall The height of the part of the ceiling wall that should be close to the optical recording medium on the outer peripheral side is gradually lower than that of the central part of the top wall, and the distance between this part and the optical recording medium is made longer than other parts. Features of the optical pickup device.