JPH04103042A - Information processor - Google Patents

Abstract

PURPOSE:To eliminate the comatic aberration by supporting independently an objective lens and a holding body, respectively, and inclining singly the objective lens. CONSTITUTION:A current is supplied to tilt coils 19, 19, and in the tilt coils 19, 19, force is generated in reverse to each other. Accordingly, a couple is given to a lens frame of an objective lens 11, plate springs 31, 31 are twisted and deformed and the objective lens 11 is inclined, and its optical axis becomes a vertical state to an optical disk. That is, the lens frame of the objective lens 11 is supported by the plate springs 31, 31, and these plate springs 31, 31 are twisted and deformed, and inclined, therefore, at the time of this inclination, a holding body 13 supported by a wire does not operate at all. In such a way, a crosstalk to a focus and a track is not generated, a comatic aberration can be eliminated completely, and recording can be executed satisfactorily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an information processing device, such as an optical head applied to an optical disk device.

(Prior Art) Conventionally, an optical head applied to an optical disk device has an optical system storage section movably supported with respect to a shaft provided on a drive base, and an optical system storage section that is mounted on the optical system storage section. The objective lens drive device (objective lens actuator) is arranged.

The objective lens drive device includes a block that supports the objective lens and a drive section that drives the block in the focus direction and the track direction.

The block of the objective lens is supported movably in the focus and track directions by a plurality of elastic wires.

Further, the optical system storage section stores an optical system including a semiconductor laser oscillator as a light source, a rising mirror (optical path changing member), and the like.

The optical head having such a configuration is moved along the shaft by the drive device, and this movement allows the optical head to roughly access the optical disk in the radial direction.

Next, the objective lens is moved in the focus direction and the track direction by the objective lens drive device for fine adjustment.

By the way, when making fine adjustments to the objective lens mentioned above, if the optical axis of the objective lens is not kept perpendicular to the optical disk, when the light passing through the objective lens is focused at the converging point of the objective lens,
The diameter of the condensed spot on the recording film of the optical disc becomes thicker.

In this way, if a pig is read or written with a large focused spot diameter, the data error rate increases and the recording density cannot be increased.

For this reason, conventionally, when the optical axis of the objective lens is not perpendicular to the optical disc, the block of the objective lens is tilted so that the optical axis becomes perpendicular to the optical disc.
I was adjusting.

(Problem to be solved by the invention) However, in the past, the objective lens was tilted by bending or twisting the wire holding the block of the objective lens, which caused cross strokes with focus and track. However, there was a problem that good recording could not be achieved.

SUMMARY OF THE INVENTION An object of the present invention is to provide an information processing apparatus that can completely eliminate coma aberration without causing a cross stroke with focus or track even if the objective lens is tilted.

[Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, the present invention provides an objective lens that focuses a light beam generated from a light source onto a recording medium, and a lens frame that fixes the objective lens. a holder that tiltably holds the lens frame via a spring material; a support member that supports the holder movably relative to the recording medium; and a drive circuit that tilts the lens frame against the spring force of the spring material so that the lens frame becomes oriented as shown in FIG.

(Function) With the above means, the objective lens and the holder are supported independently, and the objective lens can be tilted independently without operating the holder.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a schematic configuration of an optical head to which the present invention is applied.

That is, the optical disk (recording medium) 1 is rotated by a spindle motor (not shown) at a constant linear velocity relative to an optical head, which will be described later.

The optical disc 1 has a circular substrate made of glass or plastic, and the surface of the substrate is coated with a donut-shaped metal coating layer such as tellurium or bismuth.

An optical head 2 for recording and reproducing information is provided on the back side of the optical disc 1.

The optical head 2 includes a semiconductor laser oscillator 3 as a light source, a collimator lens 4, a rising mirror (optical path changing member) 5, and an objective lens 11.

The light beam oscillated from the semiconductor laser oscillator 3 is made into parallel light through a collimator lens 4, then raised in a right angle direction by a rising mirror 5, and irradiated onto the recording film of the optical disc 1 through an objective lens 11. It is now possible to do so.

The objective lens 11 is driven by an objective lens drive device (objective lens actuator) 12.

That is, as shown in FIG. 1, the objective lens 11 is fixed to a lens frame 19, and this lens frame 19 is held by a holder 13 via a tilt plate spring (spring material) 31, 31. .

Focus coils (drive coils in the focus direction) 14.14 are provided on both sides of the lens frame 19, and a pair of track coils (drive coils in the tracking direction) 15 are provided on the sides of the focus coil 14.
．． 15 are respectively provided to form an integral movable part.

Further, on the lower side of the focus coil 14.14, a tilt correction coil 19.19 as shown in FIG. 3(C) is provided.
are wound concentrically.

Each coil 141 for these focus and tilt corrections
9 exist independently from each other in the same magnetic field.

When a current is passed through the focus coil 14.14, the third
As shown in Figure (a), a force in the focus direction is generated.

Furthermore, when a current is passed through the track coil 15.15,
As shown in FIG. 3(b), the focus coil 15.1
A force is generated in a direction perpendicular to the driving force of step 5.

Furthermore, when current is passed through the tilt correction coils 19 and 19, forces in opposite directions are generated, as shown in FIG. 3(C).

On the other hand, the holder 13 is connected to a block 18, which will be described later, by four wires 16 made of non-metallic fibers, for example, carbon fibers, and supports the movable part.

Further, in the figure, 17 is a base as a holding means, and on this base 17, yokes 21a, 21b, 21c made of a magnetic material (for example, Fe) and a block 18 are integrally formed. Magnets 22a and 22b are attached to the inner wall surfaces of the yoke 21C, while the focus coils 14 and 22b are attached to the outer periphery of the yoke 21C, respectively.
A tilt correction coil 19 and a track coil 15 are wound to form a magnetic circuit (drive circuit) A.

When a current flows through the focus coil 14 and the track coil 15, the movable portion is moved by the force of the focus coil 14 acting in the focus a direction and the force of the track coil 15 acting in the tracking direction.
... are designed to be moved in a curved manner.

Further, the base 17 is supported by a tilt plate spring 35, and the base 17 is tilted in the radial direction C by a magnetic circuit B serving as an angle adjusting means.

The magnetic circuit B includes yokes 41a and 41b.

42a, 42b, magnets 43a, 43b attached to the yokes 41a, 41b, and the yoke 42
It is composed of tilt coils 43a and 43b wound around coils 43a and 42b.

When processing information, first, the optical head 2 is moved along the radial direction of the optical disk 10 by a drive device (not shown) to perform rough access.

Next, a current is supplied to the focus coil 14 and the track coil 15, and by the electromagnetic action of the magnets 22a and 22b, the objective lens 11 and the holder 13 are integrally moved in the focus direction or the track direction for fine adjustment.

By the way, during this fine adjustment, if the optical axis f of the objective lens 11 is not perpendicular to the optical disc 1, the light beam passing through the objective lens 11 will be focused at the converging point of the objective lens 1, and the optical disc will be The condensed spot on the recording film 1 becomes large.

In this case, as shown in FIG.
Current is supplied to 9.19, and the tilting coil 19.19
Forces are generated in opposite directions.

This applies a force couple to the lens frame 11a of the objective lens 11, torsionally deforms the leaf springs 31, 31, and tilts the objective lens 11 so that its optical axis is perpendicular to the optical disc 1.

As described above, the lens frame 11a of the objective lens 11 is supported by the leaf springs 31, 31, and the leaf springs 31, 31
Since the wires 16 are torsionally deformed and tilted, the holder 13 supported by the wires 16 does not operate at all during this tilting.

Therefore, crosstalk between focus and track does not occur, and good recording can be performed.

[Effects of the Invention] As explained above, the present invention supports each objective lens independently, and allows only the objective lens to be tilted regardless of the holder, which eliminates crosstalk with focus and track. There is no problem, and the effect is that good recording is possible.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a perspective view showing the support structure of the objective lens, Fig. 2 is a perspective view showing an optical disk and an optical head, and Fig. 3 is a perspective view showing the drive system of the objective lens. FIG. DESCRIPTION OF SYMBOLS 1... Optical disk (recording medium), 3... Semiconductor laser oscillator (light source), 11... Objective lens, 11a...
- Lens frame, 13... Holder, 31... Spring member,
16... Wire (supporting member), A... Drive circuit.

Claims (1)

[Claims] An objective lens that focuses a light beam generated from a light source onto a recording medium, a lens frame that fixes the objective lens, and a holder that tiltably holds the lens frame via a spring material. a support member that supports the holder movably with respect to the recording medium; and a support member that supports the lens frame against the spring force of the spring member so that the optical axis of the objective lens is perpendicular to the recording medium. An information processing device comprising: a drive circuit for tilting the device.