JPH09106548A - Disklike optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize stable high speed seek by arranging a track counting code on a groove part and/or a land part formed spirally and with the same width in the radial direction. SOLUTION: This medium is an optical disk 1 recording and/or reproducing an information signal by light irradiating on both of the groove part 2 and the land part 3 formed spirally and with the same width in the radial direction. A pit (not shown in figure) for the information signal is formed on the groove part 2 and the land part 3, and further, a track counting gray code 4 is formed on both of the groove part 2 and the land part 3 by the pit. Thus, since positional information of a track is read at any time at an access time in a recording/ reproducing device by reducing the gray code 4, the stable high speed seek is realized, and faster arrival to a target track is made possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk shape for recording and / or reproducing an information signal by light applied to both a groove portion and a land portion which are spirally formed and have the same radial width. The present invention relates to an optical recording medium.

[0002]

2. Description of the Related Art At present, optical discs for recording and / or reproducing information signals by irradiation of light have been widely used in the fields of video and audio, recording media for computers, and the like.

In such an optical disk, a guide groove called a groove is preliminarily formed on the disk substrate for tracking control, and a convex portion called a land is formed between the grooves.

In such an optical disc, up to now, data and addresses have been recorded only in the land portion, or data have been recorded only in the groove called wide groove. When data or the like is recorded only on the land portion, the groove portion records almost no data and is used only for tracking control. When data or the like is recorded only in the groove, the land portion records almost no data and is used only for tracking control.

As described above, in the optical disc as described above, the information signal is formed in only one of the two portions, even though there are two portions, that is, the groove portion and the land portion. It hindered densification.

Therefore, recently, there has been known a technique for achieving a high recording density by improving the track density by setting the width ratio of the groove portion and the land portion to 1: 1.

[0007]

By the way, when the track density is increased by setting the width ratio of the groove portion to the land portion to 1: 1 as described above, the data recorded in the adjacent tracks are Deterioration of crosstalk and reduction of cross track signal (CTS) occur.

CTS is generally an important signal when performing high speed seek. Track count can be performed with this CTS to grasp the moving distance of the optical pickup, and to know in which direction the objective lens is moving when the optical pickup stops during seek. This CTS is expressed as the difference in the amount of return light between the groove portion and the land portion.

For example, as shown in FIG. 4, a groove / land recording disk in which pits 31 are formed in both the groove portion 32 and the land portion 33 having the same radial width is considered. In this groove / land recording disk, the difference in the amount of returned light is almost zero, so that the high-speed seek cannot be performed due to the decrease in the signal amount of CTS.

The CTS is used in combination with the push-pull signal to know the moving direction of the optical pickup, but the phase of the CTS changes due to the change in the width ratio of the groove portion and the land portion. , It becomes impossible to know the moving direction of the optical pickup.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a disk-shaped optical recording medium which realizes stable high-speed seek and enables a target track to be reached more quickly.

[0012]

DISCLOSURE OF THE INVENTION In order to solve the above-mentioned problems, a disk-shaped optical recording medium according to the present invention has a groove portion and / or a groove portion formed in a spiral shape and having the same radial width.
Alternatively, a code for track counting is arranged on the land portion.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of a disc-shaped optical recording medium according to the present invention will be described below with reference to the drawings.

First, in the first embodiment, as shown in FIG. 1, by means of light applied to both the groove portion 2 and the land portion 3 which are spirally formed and have the same radial width. , The optical disc 1 for recording and / or reproducing information signals. Although not shown, pits for the information signal are formed in the groove portion 2 and the land portion 3.

In this optical disc 1, track counting codes (formed by pits, hereinafter referred to as gray codes) 4 are arranged in both the groove portion 2 and the land portion 3.

Therefore, by reproducing the gray code, the recording / reproducing apparatus can read the position information of the track at any time at the time of access, so that a stable high-speed seek can be realized and the target track can be reached faster. Is possible.

Next, in the second embodiment, as shown in FIG. 2, light radiated to both the groove portion 2 and the land portion 3 which are spirally formed and have the same radial width. The optical disc 10 records and / or reproduces an information signal. Although not shown, pits for the information signal are formed in the groove portion 2 and the land portion 3.

In this optical disc 10, a gray code 11 for track counting is arranged in the groove portion 2.

Therefore, by reproducing the Gray code 11, the recording / reproducing apparatus can read the position information of the track at the time of access, so that a stable high-speed seek can be realized and the target track can be quickly reached. It is possible.

Next, in the third embodiment, as shown in FIG. 3, the light radiated to both the groove portion 2 and the land portion 3 which are spirally formed and have the same radial width. It is the optical disc 20 for recording and / or reproducing the information signal. Although not shown, pits for the information signal are formed in the groove portion 2 and the land portion 3.

In the optical disc 20, the land portion 3 is provided with a gray code 21 for track counting.

Therefore, by reproducing the Gray code 21, the recording / reproducing apparatus can read the position information of the track at the time of access, so that a stable high-speed seek can be realized and the target track can be quickly reached. It is possible.

In the optical disc 1 of the first embodiment, the gray code pits of the groove portion 2 and the gray code pits of the land portion 3 are close to each other,
Crosstalk between gray code pits becomes large. Further, it becomes difficult to adjust the positional accuracy of the gray code pits in the radial direction when the stamper is manufactured.

On the other hand, in the optical disc 10 of the second embodiment, since the gray code pits are arranged only in the groove portion 2, only one beam is required for patterning when the stamper is manufactured. Can be easily achieved with the technology of. On the other hand, since there is no gray code pit in the target track when seeking the data recorded in the land section 3, it is necessary to seek with the gray code 11 in the groove section 2 when seeking the track in the rumb section 3. .

Further, in the optical disc 20 of the third embodiment described above, since there is no gray code pit in the groove portion 2, the crosstalk between the gray code pits becomes small. On the other hand, when the stamper is manufactured, two beams are required for patterning, which makes it difficult to adjust the position of the gray code pits in the groove portion 2 and the land portion 3 as in the first embodiment.

[0026]

According to the disk-shaped optical recording medium of the present invention, a track counting code is arranged in a groove portion and / or a land portion which are spirally formed and have the same radial width. Therefore, it realizes stable high-speed seek and enables faster reaching to the target track.

[Brief description of the drawings]

FIG. 1 is a schematic view of a first embodiment of a disc-shaped optical recording medium according to the present invention.

FIG. 2 is a schematic diagram of a second embodiment of a disc-shaped optical recording medium according to the present invention.

FIG. 3 is a schematic diagram of a third embodiment of a disc-shaped optical recording medium according to the present invention.

FIG. 4 is a sectional view of an optical disk for groove land recording.

[Explanation of symbols]

 1 Optical disc 2 Groove part 3 Land part 4 Gray code

Claims (1)

[Claims] 1. A disc-shaped optical recording medium for recording and / or reproducing an information signal by light applied to both a groove portion and a land portion formed in a spiral shape and having the same radial width. A disc-shaped optical recording medium, wherein track counting codes are arranged in the groove portions and / or the land portions.