JP2001067666A - Disk reproducing device and disk reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently reproduce data by reducing the number of track jumping times in a device which a disk is irradiated with plural reproduction beams. SOLUTION: As to the device provided with a means for reproducing in such a manner that the disk 105 whereon the data arranged in the spiral state with the constant spaces toward the outer direction from a center part of the disk are recorded, is irradiated with the reproducing beams by diffracting to N (N is natural number) beams, by preparing a means for emitting the reproducing beam in parallel keeping the spaces of M (M is natural number) tracks (to keep the spaces of N beams every M pieces), the number of track jumping times is reduced in the manner of reproducing by the track jumping in the track amount of N×(M+1)-1 after the M rotating times without track jumping for every one rotation, then the data reproduction is efficiently executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk reproducing apparatus and a disk reproducing method for reproducing data recorded on an optical disk, and more particularly to a disk reproducing apparatus for irradiating a disk with a plurality of reproduction beams. The present invention relates to an apparatus and a disk reproducing method.

[0002]

2. Description of the Related Art CD-ROM (Compact Disc-ROM) and D
2. Description of the Related Art In a device such as a VD-ROM (Digital Video Disc-ROM) for reproducing a disk on which data arranged in a spiral shape at regular intervals outward from the center of the disk is recorded, the disk has been reproduced so far. In such a case, the signal is reproduced by a single beam beam, and it is necessary to increase the rotation speed of the disk in order to increase the data transfer rate. However, since the number of revolutions is approaching the mechanical limit, a method of increasing the data transfer rate without increasing the number of revolutions by irradiating a beam in parallel and reproducing the data has been proposed. This is described in “Nikkei Electronics, News Report, April 20, 1998 Issue (No. 714), published by Nikkei Electronics”, pages P33 to P34.

[0003]

The above-described disk reproducing method of irradiating a beam in parallel is a method in which data is reproduced by irradiating seven tracks continuously outward from the center of the disk. . In this method, if data is to be obtained in a burst, a track jump must be performed every rotation. However, a track jump requires a rotation waiting time until the next data starts to be taken and a time until the data starts to be taken. Therefore, if the track jump is performed frequently, data cannot be transferred efficiently. Occurs.

[0004] The present invention has been made in view of the above points,
Its purpose is to use CD-ROM and DVD-RO
When reproducing a disk on which data arranged spirally at regular intervals outward from the center of the disk such as M using a plurality of beams, track jumps are not frequently performed. Another object of the present invention is to enable efficient data reproduction.

[0005]

According to the present invention, in order to achieve the above-mentioned object, a disk on which data arranged spirally at regular intervals outward from the center of the disk is recorded. N (N is a natural number)
In an apparatus having means for diffracting and irradiating a book beam and reproducing the beam, means for irradiating a reproduction beam in parallel at every M (M is a natural number) tracks (an interval of N beams at intervals of M) With. As a result, a track jump is not performed every rotation, and N × (M + 1) −
By performing the track jump for one track and performing the reproduction, the number of track jumps is reduced and the data is reproduced efficiently.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing a configuration of a pickup in a disk reproducing apparatus according to one embodiment of the present invention. In the figure, 101 is a semiconductor laser for irradiating a laser beam, 102 is a diffraction grating for diffracting a laser beam into N beams, 103 is a collimator lens, 1
Reference numeral 04 denotes an objective lens for irradiating the disk with a beam every M tracks, 105 denotes a disk, 106 denotes a beam irradiation width,
107 is a half mirror, 108 is a concave lens, and 109 is a photodetector.

FIG. 2 is an explanatory diagram showing a state near a beam irradiation site on the disk in the present embodiment. In the figure, 201 is the disk to be reproduced, 202 is the track line of the disk, 203 is the rotation direction of the disk at the time of reproduction, 204 is the position irradiated with the beam at the start of reproduction, and 205 is the irradiation of the beam after one rotation A position 206 is a beam irradiation position after two rotations, and 207 is a beam irradiation position after three rotations.

In this embodiment, the beam is diffracted in five directions by the pickup shown in FIG. 1 (N = 5).
A case where a beam is irradiated every track (M = 1) will be described as an example.

In the configuration shown in FIG.
A laser beam is irradiated from 01 and five beams are generated by the diffraction grating 102. The shape of the generated beam is shaped by the collimator lens 103, and the beam is incident on the objective lens 104. The five beams incident on the objective lens are respectively focused on the disk 105 and irradiated. At this time, the beam irradiation width 106 is every other track. The light beam irradiated and reflected on the disk 105 passes through the objective lens 104 and the collimator lens 103, is guided to the concave lens 108 by the half mirror 107, is condensed by the concave lens 108, and is then separated from the light by the photodetector 109. Converted to electrical signals.

As described above, in the prior art, FIG.
Irradiates a beam at every 0 track (M =
0) When data is to be obtained in bursts, it is necessary to frequently perform track jumps for each rotation of the disk, and there has been a problem that data transfer cannot be performed efficiently. Therefore, in the present invention, a CD-ROM or a DV
When a disk, such as a D-ROM, on which data arranged spirally at regular intervals outward from the center of the disk is recorded using a plurality of beams, track jumps are not frequently performed. In addition, the present invention realizes efficient data transfer. Using FIGS. 1 and 2,
The description will be continued below.

In the disk 201 shown in FIG. 2, pits having concavities and convexities are carved on the track lines 202, and data reproduction is performed by converting the concavities and convexities into electric signals of "0" and "1". I have. As described above, the five beams are emitted by the objective lens 104 every other track.

First, assume that reproduction is started from the position 204. From this state, the disk rotates in the direction of 203, and the irradiation position of the beam after one rotation is 205,
At this time, since each beam is located on the next track adjacent to the track before one rotation, there is no need to perform a track jump after one rotation, and the second rotation can be performed continuously. The beam irradiation position after two rotations is 20
6, which overlaps with the previously reproduced portion (because it overlaps with the reproduction track of the first rotation). Here, the track jump for nine tracks is performed for the first time, and the position jumps to the position 207.

As described above, according to the present invention, when reproducing a disk on which data arranged spirally at a constant interval outward from the center of the disk is recorded, the reproducing beam is set to N (N Is the natural number of beams), and in a disk reproducing apparatus having a means for diffracting and irradiating and reproducing the beams, that is, in a disk reproducing apparatus capable of increasing the data transfer speed without increasing the rotation of the disk, the reproducing beams are arranged in parallel. Has a means for irradiating every M tracks (M is a natural number) (an interval of N beams is set at every M tracks), so that a track jump is not performed every one rotation, and N × (M + 1 (1) By performing track jump for one track and performing reproduction, the number of track jumps can be reduced and data can be reproduced efficiently.

[0014]

As described above, according to the present invention, a disk, such as a CD-ROM or a DVD-ROM, on which data arranged spirally at regular intervals from the center of the disk toward the outside is recorded. When reproducing using (N is a natural number) beams, a reproducing beam is irradiated in parallel at every M (M is a natural number) tracks (the interval between N beams is M
Means), N × (M + 1) −1 after M rotations without performing a track jump every rotation.
By performing track jump for tracks and performing reproduction, the number of track jumps can be reduced, and data can be reproduced efficiently.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a pickup in a disk reproducing device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state near a beam irradiation part on a disk in the disk reproducing apparatus according to one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 101 Semiconductor laser 102 Diffraction grating which diffracts a laser beam into N lines 103 Collimator lens 104 Objective lens which irradiates a beam to a disk every M tracks 105 Disk 106 Beam irradiation width 107 Half mirror 108 Concave lens 109 Photodetector 201 Disk to reproduce 202 Track line of the disc 203 Rotation direction of the disc at the time of reproduction 204 Position irradiated by the beam at the start of reproduction 205 Irradiation position of the beam after one rotation 206 Irradiation position of the beam after two rotations 207 Position of the beam after three rotations Irradiation position

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Nagai 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term in the Digital Media Development Division of Hitachi, Ltd. 5D090 AA01 CC04 CC16 DD03 DD05 EE11 FF22 GG02 HH01 KK11 KK13 KK14 LL08 5D117 AA02 CC01 EE10 GG06 5D119 AA10 BA01 DA05 EB14 FA05 FA09

Claims (2)

[Claims] 1. A reproducing beam is diffracted into N (N is a natural number) beams from a disk on which data arranged spirally at regular intervals outward from the center of the disk is recorded, and is irradiated on the disk. A disk reproducing apparatus for reproducing data by irradiating a reproduction beam every M (M is a natural number) tracks. 2. A reproducing beam is diffracted into N (N is a natural number) beams from a disk on which data arranged spirally at regular intervals outward from the center of the disk is recorded, and M (M Is a natural number) A disk reproducing method characterized in that data is reproduced by irradiating the disk with a reproduction beam every other track.