JPS6230177Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a collimator lens position adjustment device for an optical pickup, and in particular, the length of the through hole for storing the collimator lens is formed to be shorter than the length of the collimator lens, and the through hole for storing the collimator lens is formed to have a length shorter than that of the collimator lens. An opening groove is provided on both sides of the lens, and a long adjustment lever having a through hole for passing the light beam at the tip is inserted into the opening groove, and the position of the collimator lens is adjusted by operating the adjustment lever. The present invention relates to a collimator lens position adjustment device for an optical pickup.

When creating an optical system for an optical pickup, adjustment of the light beam is always necessary. To adjust the light beam, it is sufficient to adjust the laser light source position or the collimator lens position, but generally adjusting the collimator lens with an adjustment rod etc. means blocking the light beam, so it is necessary to adjust the laser light source position. It is easier to adjust. Conventionally, there have been devices as shown in FIGS. 1 and 2 that adjust the position of the laser light source. That is, an elastic O-ring 2 is attached to a hollow cylindrical flange portion 1A provided on the optical pickup main body 1,
The laser light source 3 is inserted into the hollow cylinder while fitting the key groove 3A recessed in the flange part of the laser light source 3 into the key 1B protruding from the hollow cylinder, and the washer 4 is attached to the flange part of the laser light source 3. A screw ring 5 is pressed against the washer 4 and screwed onto a screw portion 1C provided near the entrance of the hollow cylinder. The position of the laser light source 3 is then adjusted by adjusting the screw ring 5.

In this prior art, the outer diameter of the threaded ring 5 is larger than the diameter of the flange portion of the laser light source 3, and the length of the threaded portion 1C is greater than the thickness of the threaded ring 5, so that the optical pickup main body 1 is miniaturized. There was a problem that it became a hindrance.

This idea was created by focusing on the problems of the conventional technology, by adjusting the position of the collimator lens without adjusting the position of the laser light source or once blocking the light beam. , aims to solve the above problems.

This invention will be explained below based on the drawings.

FIG. 3, FIG. 4, FIG. 5, and FIG. 6 are diagrams showing one embodiment of this invention.

First, the structure will be explained. Reference numeral 11 denotes a through hole for storing a collimator lens provided in the optical pickup main body 12, and is formed to be shorter than the length l of the collimator lens 13.

Reference numeral 14 denotes an open groove, which is provided on both sides of the collimator lens housing through hole 11, and the tip of the collimator lens 13 protrudes into the open groove 14.

Reference numeral 15 is an adjustment lever, and the optical pickup main body 12
It is inserted into the open groove 14 when adjusting the position of the collimator lens 13 from the outside. Adjustment lever 1
A light beam passage hole 15A larger than the diameter of the collimator lens 13 is formed at the tip of the lens 5, and the other end protrudes from the optical pickup body 12.

The length of the adjustment lever 15 is L, the height is H, the thickness is T, the depth of the opening groove 14 is L', the length is H', the diameter of the collimator lens 13 is D, and the amount of adjustment is
When l' is the outer separation distance of the open groove portion 14, the dimensions are determined so that H'>H>D, L>L', and W≧2T+l+l'.

The adjusting lever 15 is made of a rigid plate that is as thin as possible, so that the outer distance W of the groove 14 can be made small.

Incidentally, even if the opening groove portion 14 is provided, since the opening groove portion 14 occupies a small proportion of the optical pickup main body 12, it does not become an obstacle when downsizing the optical pickup main body 12.

Next, the action will be explained.

A semiconductor laser 20 is mounted on the optical pickup main body 12,
A polarizing beam splitter 21, a quarter-wave plate 22, a 90-degree deflection mirror 23, a circular lens 24, and a 4-split optical sensor 25 are fixed, an objective lens 27 is fixed to an actuator 26, and a through hole 11 for storing a collimator lens is fixed. The collimator lens 13 is temporarily attached to. Then, the tip of the adjustment lever 15 is inserted into the opening groove 14, and the other end of the adjustment lever 15 is operated left and right. With this operation, the collimator lens 13
The position of the collimator lens 13 can be determined by moving the collimator lens housing through hole 11 from side to side. Since the light beam from the semiconductor laser 20 and the reflected light from the disk 28 pass through the light beam passage hole 15A of the adjustment lever 15, the light beam is not interrupted by the operation of the adjustment lever 15.

The amount of movement l'' of the collimator lens 13 is determined by the amount of adjustment of the adjustment lever 15, A, as shown in FIG.
If the height is L'' and the height from the tip of the adjustment lever 15 to the collimator lens 13 is a, then l''=A×
It is given by a/L''. From this, if the ratio of a/L'' is made small, the collimator lens 13 can be easily finely adjusted.

When the position adjustment of the collimator lens 13 is completed, the adjustment lever 15 is pulled out from the opening groove 14, and adhesive is applied to the collimator lens storage through hole 11 from the outside of the optical pickup main body 12 through the through hole (not shown). is injected, and the collimator lens 13 is fixed to the optical pickup main body 12. Further, the entrance portion of the open groove portion 14 is sealed with a plate material or the like.

As explained above, in this invention, the length of the collimator lens housing through hole is formed shorter than the length of the collimator lens, and grooves are provided on both sides of the collimator lens housing hole, and the tip of the through hole is formed to be shorter than the length of the collimator lens. By inserting a long adjustment lever with a through hole for beam passage into the opening and operating the adjustment lever, the light beam can be blocked without increasing the size of the optical pickup body. The effect is that the light beam can be adjusted without having to do so.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view of the prior art, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, Fig. 3 is a plan view of this invention, Fig. 4 is a side view of this invention, and Fig. 5 is a sectional view of this invention. A partially cutaway perspective view of the device; FIG. 6 is a sectional view taken along line B-B in FIG. 5;
FIG. 7 is a diagram showing the relationship between the amount of movement of the collimator lens and the amount of adjustment of the adjustment lever. 1... Optical pickup body, 2... O-ring,
3... Laser light source, 4... Washer, 5... Screw ring, 11... Through hole for storing collimator lens,
12... Optical pickup main body, 13... Collimator lens, 14... Opening groove, 15... Adjustment lever.

Claims (1)

[Scope of utility model registration request] The length of the collimator lens housing through hole is formed to be shorter than the length of the collimator lens, and open grooves are provided on both sides of the collimator lens housing through hole,
A collimator lens position adjustment device for an optical pickup, in which a long adjustment lever having a through hole for passing a light beam at its tip is inserted into the opening, and the position of the collimator lens is adjusted by operating the adjustment lever. .