JPH01178143A - Optical disk device - Google Patents

Abstract

PURPOSE:To facilitate adjustment for an optical axis by almost aligning the optical axis of light which reciprocates between an optical path deflecting means and a parallelogramic prism to the turning shaft center of a turn driving means, and furthermore, placing the optical path deflecting means so as to remain at the same position without being changed for a fixed optical system. CONSTITUTION:The fixed optical system 1, and the turn driving means 4 on which the parallelogramic prism 5 and an objective lens 6 are placed and operated integrally are fixed on a base 2, respectively. Also, the central optical axis of the objective lens 6 and the turning shaft center of the turn driving means 4 are adjusted in parallel via the prism 5, and furthermore, the optical axis of the light which reciprocates between the prism 5 and a galvanomirror 3 are adjusted so as to be aligned to the turning shaft center of the turn driving means 4. Therefore, it is possible to adjust the reflecting plane of the galvanomirror 3 at a prescribed position where the turning shaft center of the turn driving means can be set in parallel with the optical axis of the light from the galvanomirror 3, and to adjust the fixed optical system 1 so as to align the optical axis of the light from the reflecting plane to the turning shaft center of the turn driving means 4. In such a way, the adjustment for the optical axis can be performed easily.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an optical disc device.

Conventional technology Figure 3 shows the configuration of a conventional optical disk device, and Figure 4 shows the configuration of a conventional optical disk device.
It shows a partially enlarged view of the figure. That is, 11 is a fixed optical system having a light emitting means and a light receiving means;
Reference numeral 4 denotes a rotation driving means on which a parallelogram-shaped prism 16 and an objective lens 16 are mounted and move as a unit, and 13 is a galvano mirror serving as an optical path deflection means, each of which is fixed on the base 12. . The central optical axis of the objective lens 16 and the rotational axis of the rotational drive means 14 are the same as those of the parallelogram-shaped prism 1.
The optical axis of the light passing back and forth between the parallelogram-shaped prism 16 and the galvano mirror 13 is adjusted to coincide with the rotation axis of the rotation drive means 14. Note that the support mechanism for the objective lens 16 including the focus actuator and the like will not be described here and is not illustrated.

The operation of the optical disk device configured as described above will be described below. After the light emitted from the fixed optical system 11 is reflected by the galvanometer mirror 13, the light is transmitted to the rotary drive means 14.
parallelogram-shaped prism 16.
The light enters the objective lens 16 and forms an image on the optical disk 17. The optical disc 17 has a recording layer on which information can be recorded or reproduced by optical means, and is mounted and rotated by a spindle motor (not shown). When the rotation drive means 14 is rotated, the objective lens 16, which is provided to move integrally with the rotation drive means 14, moves in an arc shape, making its trajectory approximately coincide with the radial direction of the optical disc 17, and the rotation By controlling the driving means 14 and the galvanometer mirror 13 in parallel by a control means (not shown) using a tracking error signal obtained from the fixed optical system 11, all tracks on the optical disk 17 can be accessed.

Problem to be Solved by the Invention However, in such a configuration, if the angle variation of the reflecting surface 13 & occurs due to the assembly precision of the galvanometer mirror 13,
Since the relationship between the input and output of the galvanomirror 13 with respect to the mounting reference is not constant, a tilt occurs, and adjustment is required to correct this tilt. This trouble may be due to the error signal obtained from the light receiving means of the fixed optical system 11, due to the fact that the optical axis moves greatly when the rotation drive means 14 is rotated, or because it causes vignetting. This results in unstable control. Therefore, in order to align the rotational axis of the rotational drive means 14 with the optical axis, the galvanometer mirror 13 and the fixed optical system 11 must be adjusted in an arbitrary direction in a correlated manner, so that the adjustment cannot be converged. The problem was that it was difficult to do.

Means for Solving the Problems In order to solve the above problems, the optical disk device of the present invention has the following features:
A galvanomirror is provided with an adjustment mechanism having two rotation axes, and is configured to be mounted on a fixed optical system.

Effects The present invention simplifies the adjustment means regarding the optical axis by the above-described configuration.

Embodiment Hereinafter, an optical disk device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of an optical disk device according to an embodiment of the present invention, and FIG. 2 is a partially enlarged view of FIG. 1.

1 is a fixed optical system having a light emitting means and a light receiving means; 4 is a rotary drive means on which a parallelogram-shaped prism 5 and an objective lens 6 are mounted and move as one; each is mounted on a base 2; Fixed. Reference numeral 3 denotes a galvanomirror, which is an optical path deflecting means, having two rotating axes for rotating the reflecting surface 3a, which is fixed by a known method after being adjusted to a predetermined position.
It is attached to the fixed optical system 1. The central optical axis of the objective lens 6 and the rotational axis of the rotational driving means 4 are adjusted to be parallel via the parallelogram-shaped prism 6, and are further moved back and forth between the parallelogram-shaped prism 6 and the galvanometer mirror 3. The optical axis of the light is adjusted to coincide with the rotation axis of the rotation drive means 4. Note that the support mechanism for the objective lens 6 including the focus actuator and the like is not explained here and is not illustrated.

The operation of the optical disk device configured as described above is the same as that of the conventional example, so a description thereof will be omitted. The difference between the conventional example and the embodiment of the present invention is that the galvanometer mirror 3 is provided with an adjustment mechanism having two rotation axes and is fixed to a fixed optical system. As a result, firstly, the two rotation axes (A-A, B -B) enables the sequential adjustment of adjusting the reflective surface 3a and secondly adjusting the fixed optical system so that the optical axis of the light from the reflective surface 3a coincides with the rotational axis of the rotational drive means 4. This provides an optical disc device that allows easy adjustment regarding the optical axis.

Effects of the Invention As described above, the present invention provides a rotary drive means for moving an objective lens in an arc shape substantially along the radial direction of a disc-shaped recording medium;
A fixed optical system having a light emitting means and a light receiving means, and a mechanism that deflects light emitted from the fixed optical system by a small angle to reach the objective lens of the rotary drive means and is adjustable in at least two directions. a control means for controlling the rotary drive means and the optical path deflection means in parallel based on a tracking error signal obtained from the fixed optical system; and a rotary axis of the rotary drive means and the objective. a parallelogram-shaped prism having two parallel opposing total reflection surfaces that optically connect the lens center optical axis; and a base on which the rotation driving means and the fixed optical system are mounted. The optical axis of the light traveling between the optical path deflecting means and the parallelogram-shaped prism is made to substantially coincide with the rotational axis of the rotational drive means, and the optical path is fixed in position with respect to the fixed optical system. By installing the deflecting means, it is possible to provide an optical disk device that allows easy adjustment regarding the optical axis.

[Brief explanation of the drawing]

It is. FIG. 3 shows the configuration of a conventional optical disk device, and FIG. 4 is a partially enlarged view of FIG. 3. 1...Fixed optical system, 2...Base, 3.
...Galvano mirror 14 as optical path deflection means...
...Rotation drive means, 6...Parallelogram-shaped prism, 6...Objective lens, 3a, 13a...
...The radiation surface of a galvano mirror.

Claims (2)

[Claims] (1) A rotation driving means for moving the objective lens toward the center of the recording medium, a fixed optical system having a light emitting means and a light receiving means, and the rotation driving means for deflecting the light emitted from the fixed optical system. a control means for controlling the rotation drive means and the optical path deflection means in parallel based on a signal obtained from the fixed optical system; and rotation of the rotation drive means. The prism includes a prism having two parallel opposing total reflection surfaces that optically connect the axis and the central optical axis of the objective lens, and a base on which the rotation driving means and the fixed optical system are mounted. An optical disc device characterized in that the fixed optical system includes the optical path deflecting means. (2) An optical disk according to claim 1, characterized in that the optical axis of the light passing back and forth between the optical path deflecting means and the parallelogram prism is substantially aligned with the rotational axis of the rotational driving means. Device. (3) The optical disc device according to claim 2, wherein the optical path deflecting means includes a mechanism that can be adjusted in at least two directions.