JP2005339702A - Optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk device which has a satisfactory access property to an optical disk and reduces power consumption. <P>SOLUTION: An optical pickup device (5) is equipped with an objective lens (11) for converging an optical flux (17) from a light source (9) on the optical disk (10), a detection means (12) for detecting spherical aberration on the basis of reflected light from the optical disk, and a spherical aberration correction means (8) having a correction lens (14) arranged on an optical axis and a correction lens moving means (14a and 15) for moving the correction lens in the direction of the optical flux, and is provided with a transmission means (7b and 15b) for arranging a power source (7) for moving the correction lens to a base (1) side and transmitting power from the power source to the moving means when the optical pickup device is at a specific position so as to move the correction lens to a position based on a detection result of the detection means by the power. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical disk device, and more particularly to a mechanism for correcting spherical aberration when a signal is recorded or reproduced on an optical disk.

In an optical disk apparatus equipped with an optical pickup that records or reproduces a signal to or from an optical disk, in order to record / reproduce a high-density signal, the wavelength of a laser as a light source is shortened or the numerical aperture of an objective lens is increased. It is illustrated.
By the way, in an optical disk, spherical aberration caused by variation in the thickness of the protective layer is generated in proportion to the fourth power of the numerical aperture of the objective lens of the optical pickup.
Therefore, the spherical aberration becomes larger as the objective lens has a higher numerical aperture, and it has been necessary to correct this as an optical disc apparatus.

A spherical aberration correcting means has been devised for correcting the spherical aberration by moving at least one of a positive lens and a negative lens arranged in the optical path of the optical pickup along the optical axis (see Patent Document 1). ).
The spherical aberration correction means includes conversion means for converting the rotational movement of the lead screw of the actuator (drive means) into linear movement in the optical axis direction, and moves the negative lens in the optical axis direction through the conversion means. is there.
JP 2002-334476 A

  By the way, in the optical disk apparatus, the objective lens of the optical pickup apparatus is reciprocated in the radial direction of the disk in order to record / reproduce signals with respect to the disk.

However, the above-described optical pickup device is integrally equipped with spherical aberration correction means.
That is, the moving optical pickup device is mounted with spherical aberration correcting means and driving means for driving it.

For this reason, the optical pickup device increases in size and weight, and it is difficult to move it in the radial direction at high speed, and it is difficult to accurately stop (move) to a desired position due to inertia. For this reason, there is a problem that the accessibility to the disk is hindered.
In addition, there is a problem that the load on the drive source for driving the optical pickup device becomes large and it is difficult to save power in the optical disk device.
These problems are particularly problematic when the optical disk apparatus is mounted on an imaging apparatus such as a video camera using a disk as a recording medium.

  Therefore, the problem to be solved by the present invention is to provide an optical disc apparatus that has good accessibility to an optical disc and can reduce power consumption even when spherical aberration correcting means is provided.

In order to solve the above problems, the present invention has the following configuration as means.
That is, the invention according to claim 1 is a base (1) having a driving means (2) for supporting and rotating the optical disk (10), and the optical disk (10) moved in the radial direction of the optical disk (10). And an optical pickup device (5) for recording or reproducing signals with respect to
The optical pickup device (5) includes a light source (9), an objective lens (11) for condensing a light beam (17) from the light source (9) on the optical disc (10), and the light beam (17). Detection means (12) for detecting spherical aberration based on reflected light from the optical disc (10), a correction lens (14) disposed on the optical path of the light beam (17), and the correction lens (14) are connected to the light beam. Spherical aberration correction means (8) having correction lens moving means (14a, 15) for moving in the direction of (17), and the power source (7) for moving the correction lens (14) is the base ( 1) A transmission means (7b, 15b) that is disposed on the side and transmits the power from the power source (7) to the moving means (14a, 15) when the optical pickup device (5) is in a specific position. ) And before By power, said an optical disk apparatus characterized by comprising configured to move the correction lens (14) to the detection result based on the position detection means (12) (100).

  According to the present invention, excellent accessibility can be obtained and power consumption can be reduced.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to FIGS.
FIG. 1 is a plan view showing an embodiment of an optical disc apparatus of the present invention.
FIG. 2 is a plan view showing the main part in the embodiment of the optical disk apparatus of the present invention,
FIG. 3 is a first diagram for explaining a main part in the embodiment of the optical disk apparatus of the present invention.
FIG. 4 is a second diagram for explaining a main part in the embodiment of the optical disk apparatus of the present invention.

First, an optical disk apparatus according to an embodiment will be described with reference to FIG.
An optical disk apparatus 100 of this embodiment has a box-shaped base 1 and a rotation center 3, a disk clamping mechanism 2 that clamps and rotates a disk 10 (not shown in the figure), and an optical pickup apparatus 5. And have.

The optical pickup device 5 has a housing 5 a that is slidably supported by a pair of parallel shafts 4 and 4 fixed to the base 1.
The lead meshing portion 5b provided on the housing 5a is configured to mesh with the lead screw 6a of the first motor 6 and move in the radial direction (arrow D1) according to the rotation of the lead screw 6a. .
The base 1 is attached with a second motor 7 for driving spherical aberration correction means 8 (details will be described later) provided in the optical pickup device 5.

Next, the optical pickup device 5 will be described in detail with reference to FIG. FIG. 2 is schematically shown for easy understanding.
The optical pickup device 5 has a light source 9, an objective lens 11 for condensing a light beam from the light source 9 on the surface of the disk 10, and an optical path between the light source 9 and the objective lens 11. The arranged spherical aberration correcting means 8 and the detecting means 12 for detecting the reflected light from the disk 11 and detecting the spherical aberration are provided.

The spherical aberration correction means 8 includes a positive lens 13 and a negative lens 14 and a lead screw 15 arranged in the direction of the optical axis CL.
The negative lens 14 has a meshing portion 14b that meshes with the lead screw 15 in a holding frame 14a that holds the negative lens 14, and the negative lens 14 is configured to move in the optical axis CL direction in accordance with the rotation of the lead screw 15. ing.
In the embodiment, the negative lens 14 is moved. However, the positive lens 13 may be moved.

  The holding frame 14a of the negative lens 14 is urged in the axial direction (arrow D2) of the lead screw 15 by a coil spring (biasing means) 16 to remove backlash due to backlash.

The lead screw 15 is provided with a connecting portion 15 b for connecting to the shaft of the second motor 7 on one end side thereof.
On the other hand, in the 2nd motor 7, the connection part 7b engaged with the connection part 15b in the relationship of an unevenness | corrugation is provided in the front end side of the axis | shaft 7a.
In the embodiment, the connecting portion 7b on the second motor 7 side has a convex shape, and the connecting portion 15b on the lead screw 15 side has a concave shape, but this concavity and convexity may be reversed.

By the way, the above-described variation in the thickness of the protective layer in the optical disc is different for each disc used, and the variation in each location on one disc is small.
Accordingly, the spherical aberration correction is performed before the recording / reproducing operation when the disk is replaced, and it is not necessary to always perform correction for the same disk.

Therefore, in the embodiment, in the initial operation on the loaded disc 10, the optical pickup device 5 is positioned in the vicinity of the outermost periphery of the disc 10 to execute the spherical aberration correction operation.
That is, the connecting portions 7 b and 15 b are engaged and connected when the optical pickup device 5 is at a position corresponding to the adjustment regions X1 to X2 near the outermost periphery of the disk 10.

FIG. 2 shows a state in which the optical pickup device 5 in FIG. 1 has moved to the leftmost side in the drawing.
Spherical aberration correction is performed in a state where both the connecting portions 7b and 15b are connected.

During the correction operation, the housing 5a is moved to a position where the emitted light 17 from the objective lens 11 enters the adjustment regions X1 to X2 of the optical disc 10.
Then, the negative lens 14 is moved and held at a position where the spherical aberration is minimized in the detection result of the detection means 12. This movement is performed through the holding frame 14 a by the rotation of the second motor 7.
At this time, as described above, the backlash with respect to the lead screw 15 of the holding frame 14a is removed by the biasing of the biasing means 16, so that the position of the negative lens 14 does not shift.

Next, the connecting portions 7b and 15b will be described in detail with reference to FIGS.
<About uneven width>
In FIG. 3, when the concave width of the connecting portion 15b is a, the convex width of the connecting portion 7b is b, and the diameters of the connecting portions 7b and 15b are equally c, a> b is given in the rotational direction. It is.
When the spherical aberration correction operation is completed, the second motor 7 is rotated by a rotation angle α in the direction opposite to the direction in which the second motor 7 was rotated at the end of the correction.
The rotation angle α is set so that α <(ab) / πc.

  As a result, the spherical aberration correction operation is completed, the housing 1 is moved for recording / reproducing operation with respect to the disk 10, the connection between the connecting portions 7b and 15b is once opened, and these are connected again for correction. At this time, the concave portions and the convex portions of both the connecting portions can be smoothly re-engaged.

<About the depth of unevenness>
When the width of the adjustment regions X1 to X2 is ΔX, the recess depth of the connecting portion 15b is d and the protrusion depth (height) of the connecting portion 7b is e as shown in FIG. > ΔX, e> ΔX.
Thus, in the spherical aberration correction operation, when the optical pickup device 5 is at a position corresponding to the adjustment region X1 to X2 in the vicinity of the outermost periphery of the disc, both the connecting portions 7b and 15b are always engaged and connected. Therefore, the correction operation can be performed reliably.

As described above, according to the embodiment described in detail, since the second motor for driving the spherical aberration correcting means is disposed not in the optical pickup device but in the housing of the optical disc apparatus main body, the optical pickup device can be reduced in size and weight. Is possible.
Therefore, the optical pickup device can be moved at high speed, and can be stopped (moved) with high accuracy to a desired position, and the accessibility to the disk is improved.
In addition, since the load on the drive source for driving the optical pickup device is small, the power consumption of the optical disk device can be reduced.
Therefore, it becomes easy to mount this optical disk apparatus on an imaging apparatus such as a video camera using the disk as a recording medium.

The embodiment of the present invention is not limited to the configuration and procedure described above, and it goes without saying that modifications may be made without departing from the scope of the present invention.
In the embodiment, the spherical aberration correction operation is performed in the vicinity of the outermost periphery of the disk, but may be configured to be performed in the vicinity of the innermost periphery. In this case, the second motor 7 is disposed on the right side in FIGS. 1 and 2, and the connecting portion 15b of the lead screw 15 is provided on the right end portion in both drawings.

It is a top view which shows the Example of the optical disk apparatus of this invention. It is a top view which shows the principal part in the Example of the optical disk apparatus of this invention. It is the 1st figure explaining the principal part in the Example of the optical disk device of this invention. It is a 2nd figure explaining the principal part in the Example of the optical disk apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 Disk drive mechanism 3 Center of rotation 5 Optical pick-up apparatus 5a Case 5b Lead meshing part 6 First motor 6a Lead screw 7 Second motor 7a Shaft 7b Connecting part 8 Spherical aberration correcting means 9 Light source 10 Disk 11 Objective lens 12 Detection means 13 Positive lens 14 Negative lens 15 Lead screw 15b Connecting portion 16 Coil spring (biasing means)
17 Light flux, outgoing light 100 Optical disc device

Claims (1)

A base having a driving means for supporting and rotating the optical disk;
In an optical disc apparatus provided with an optical pickup device that moves in the radial direction of the optical disc and records or reproduces signals on the optical disc,
The optical pickup device is:
A light source, an objective lens for condensing the light beam from the light source on the optical disc, a detecting means for detecting spherical aberration based on the reflected light of the light beam from the optical disc, and a correction disposed on the optical path of the light beam A spherical aberration correction means having a lens and a correction lens moving means for moving the correction lens in the direction of the luminous flux,
A power source for moving the correction lens is disposed on the base side, and a transmission unit is provided for transmitting the power from the power source to the moving unit when the optical pickup device is at a specific position.
An optical disc apparatus configured to move the correction lens to a position based on a detection result of the detection means by the power.

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