JPS62170028A - Adjusting mechanism for tilt of actuator - Google Patents

Abstract

PURPOSE:To effectively prevent the deterioration of servo accuracy by providing a projection at the inner side of an actuator from an edge and fitting the actuator via a spacer obliquely to the fulcrum of the said projection so as to decrease the displacement in the optical axis direction. CONSTITUTION:Projections 5a, 5b, 6a, 6b are formed at inner side from screw fixing holes 3a, 3b, 4a, 4b of an optical pickup main body 2. In loading the actuator 1 mounted with an objective lens 10, spacers 7a, 7b are inserted and the actuator 1 is mounted on the main body 2 by screws 8a, 8b, 9a, 9b while using the projections 5a-6b at the inner side of the edge as fulcrums. Since the fulcrums come inner than a conventional mechanism, the displacement of the objective lens 10 in the optical axis direction is decreased and the deterioration in the accuracy of the focus servo is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an actuator tilt adjustment mechanism in an optical pickup used for reproducing information recorded on an optical recording disk or recording information on such a disk. Regarding.

[Conventional technology]

In an optical pickup, generally, an optical system such as a light source or a beam splinter, and a photodetector are attached to the optical pickup body, and an actuator with an objective lens is attached to the optical pickup body to direct the light from the light source to the objective. The light is irradiated onto the disk through a lens, and the reflected light is received by a photodetector through an objective lens.

In such an optical pickup, in order to accurately record and reproduce information, it is necessary to set the optical axis of the objective lens perpendicular to the disk.

Therefore, as shown in FIG. 6, for example, an actuator 22 having an objective lens 21 and an optical pickup main body 2
The actuator 22 is tilted with respect to the optical pickup main body 23 and fixed with screws 25 by making the joint surfaces of 3 flat and interposing a spacer 24 between them to correct the inclination of the optical axis of the objective lens 21. Conventionally, an actuator tilt adjustment mechanism has been proposed.

[Problem that the invention seeks to solve]

However, in the conventional actuator tilt adjustment mechanism shown in FIG. 6, the actuator 22 is tilted with respect to the optical pink-up body 23 using the edge of its joint surface as a fulcrum. Therefore, as shown in FIG. 7, the width of the actuator 22 is set to X, the distance between the optical axis of the objective lens 21 and the edge of the actuator 22 is set to -, and the actuator 22 is θ When tilted, the objective lens 21 is largely displaced by approximately -tanθ in the optical axis direction, and the objective lens 21 relative to the disk is
There is a problem that the accuracy of the focus servo of No. 1 is reduced.

This invention was made by focusing on such conventional problems, and in order to correct the inclination of the optical axis of the objective lens,
An object of the present invention is to provide a seven-actuator tilt adjustment mechanism that is appropriately configured to reduce the displacement of an objective lens in the optical axis direction when tilting an actuator with respect to an optical pink-up body.

[Means and effects for solving the problem] In order to achieve the above object, the present invention provides at least two protrusions on the actuator and/or the optical pink amplifier body,
A spacer for correcting the inclination of the optical axis of the objective lens is interposed between these actuators and the optical pink-up body, so that the actuator is tilted with respect to the optical pink-up body using at least one protrusion as a fulcrum. Configure.

〔Example〕

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

In this example, the actuator l with the objective lens
is screwed to the optical pickup main body 2 so that the inclination can be adjusted in the X and Y directions that are orthogonal to each other. As shown in the plan view in FIG. 2, the optical pickup main body 2 has an
Two screw fixing holes 3a, 3b and 4a, 4b are formed in each direction, and two protrusions 5a, 5 are respectively formed on the side of the optical path hole 2a from these screw fixing holes.
b and 6a.

6b is formed.

In this example, the actuator l alone measures the optical axis (pulling star) of the objective lens in the X and Y directions in advance,
A spacer to correct that tilt? a, 7b into one screw fixing hole (3b in FIG. 1,
Insert the actuator l into the part 4a) and tighten the screw 8.
It is attached to the optical pickup main body 2 by a, 8b and 9a, 9b.

In this configuration, when paying attention to the X direction, as shown in FIG. 3, the actuator 1 is tilted about the protrusion 5a as a fulcrum due to the insertion of the spacer 7a. Here, the fourth
As shown in the figure, the width of the actuator 1 is X, the distance between the optical axis of the objective lens 10 and the edge of the actuator is X, the distance between the protrusion 5a and the optical axis of the objective lens 10 is X, As, the actuator l is connected to the optical pickup main body 2.
If the objective lens 10 is tilted by θ relative to the optical axis, the objective lens 10 will be displaced approximately by Lan θ in the optical axis direction, but since × and <−, the amount of displacement will be smaller than in the case of FIG.

This also applies to the Y direction.

Note that this invention is not limited only to the embodiments described above, and numerous modifications and changes are possible. For example, in the above embodiment, two screw fixing holes and a protrusion were provided in the optical pickup main body 2 in the X and Y directions perpendicular to each other, with the optical path hole 2a as the center. As shown, three screw fixing holes 11a
~llc and the protrusions 12a to 12c can be formed symmetrically with respect to the optical path hole 2a to similarly adjust the inclination of the actuator 1 in the X and Y directions, or it is possible to form two protrusions. It is also possible to configure the inclination to be adjustable only in one direction.

Further, the protrusion may be formed on the bottom of the actuator 1 or on both of the optical pickup body 2, and if the protrusion is formed at a position closer to the optical axis of the objective lens lO than the edge of the actuator 1, it can be formed with a screw. It may be outside the fixed position.

〔Effect of the invention〕

As described above, according to the present invention, the actuator rotates the optical beam with the protrusion as the fulcrum on the inside of the edge of the actuator, that is, on the optical axis side of the objective lens.

Since the lens is tilted with respect to the main body of the Kurasopu, the displacement of the objective lens in the optical axis direction can be reduced, and therefore, it is possible to effectively prevent a decrease in the accuracy of the focus servo.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing one embodiment of the present invention, FIG. 2 is a partial plan view of the optical pink amplifier main body shown in FIG. 1, and FIGS. 3 and 4 are views of the embodiment shown in FIG. 1. FIG. 5 is a diagram showing a main part of a modified example of the present invention, and FIGS. 6 and 7 are diagrams for explaining the conventional technology. 1... Actuator 2... Optical pickup body 2a... Optical path holes 3a, 3b, 4a, 4b --- Screw fixing hole 5a
, 5b, 6a, 6b-Protrusion 7a, 7b-Spacer 8a, 8b, 9a, 9b... Screw 10
...Objective lenses 11a-llc...Screw fixing holes 12a-12c...Protrusions Fig. 2 Fig. 3 Fig. 4

Claims (1)

[Claims] 1. At least two protrusions are provided on an actuator having an objective lens and/or an optical pickup body to which the actuator is mounted, and the inclination of the optical axis of the objective lens is corrected in a part between the actuator and the optical pickup body. At least one of the actuators is
An actuator tilt adjustment mechanism, characterized in that the actuator tilt adjustment mechanism is configured to be tilted with respect to the optical pickup main body using each of the protrusions as a fulcrum.