JPH09231581A - Optical disk and method for reproducing optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk having compatibility with a conventional compact disk. SOLUTION: A wobbling pit are WWA frequency-modulated by recording data (reflection rate, laser power, linear speed or the like) is provided in the innermost side of an optical magnetic disk and then a track is formatted so as to make recording TOC information an area TOC. The wobbling pit is easily provided during manufacturing of a master disk and easily read by a conventional CD (LD) player.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc capable of recording information on a spiral track by irradiating a laser beam, for example, and a reproducing method thereof.

[0002]

2. Description of the Related Art An optical disc in which concave pits are spirally arranged on a recording surface of an optical disc, and the dimensions of the concave pits are modulated based on recording information so that a digital audio signal or a video signal can be reproduced. (C
D, VD) are widely spread, but pits are formed on such a read-only optical disk by a recording medium whose reflectance changes when irradiated with laser light or by heat generated when irradiated with laser light. A writable optical disk capable of recording and reproducing information by using a recording medium that can be formed is also in the stage of practical application.

In such a writable optical disc, it is usually necessary to form a spiral pre-groove in advance on the recording surface of the optical disc in order to guide a laser beam for writing, and at the same time, the writing is performed. For this purpose, the laser power, the reflectivity of the recording surface, the linear velocity of the optical disc, the strategy of the write pulse, etc. are previously added to the innermost track of the optical disc as information required for recording.

FIG. 2 shows an example of the pre-formatting of such a writable optical disc. The disc shape (inner diameter r ₁ , outer diameter r ₂ ), track pitch, etc. are the same as those of the current CD.
(Compact disc) and is almost the same. The recording surface is formed of a film of an organic dye material or an inorganic material that is sensitive to light.

Also, several tracks on the inner peripheral side (radius 23 to 2
In the area of 5 mm), as shown in FIG. 3, a recording data area WFA in which the above-mentioned recording conditions are recorded in the pits P by embossing or the like is provided beforehand. When copying information from a conventional CD, the TOC information (performance time, song number, etc.) of the signal to be recorded in the area next to the recording data area WFA is recorded as dot information, and then music information, etc. Will be recorded.

[0006]

However, in a write-type optical disc having an organic dye material or the like as the recording surface, the modulation degree of the RF signal obtained by the pits P of the recording data area WFA which is formed in advance and the When the recorded information is reproduced, there may be a considerable difference in the modulation degree of the RF signal, which causes a problem when the reproduction player reproduces the copied optical disk as it is. In addition, when the recording surface of the optical disc changes the reflectance in response to light, the polarity of the reproduction RF signal of the recording data area WFA and the reproduction RF signal of the recorded dot information may be different. However, there is a problem that a special reproduction system is required due to the difference.

[0007]

The present invention has been made in view of the above problems, and the recording conditions of the optical disk are recorded in order to obtain an optical disk that is as consistent as possible with a conventional CD. In the area, wobbling pits modulated in accordance with recording condition data are provided in advance.

A pit train in which the wobble period is modulated by data of optimum recording conditions (reflectance, laser power, linear velocity, modulation pulse waveform for setting pit shape) required for an optical disk is provided. Therefore, at the time of recording, while wobbling pits indicating the recorded data are detected by the push-pull method or the like and the recording conditions are set, the recorded contents of the CD or the like are copied,
Also, during reproduction, the information written by a normal CD reproduction player can be reproduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the optical disc of the present invention. In particular, an area (hereinafter, referred to as recording wobbling) in which data indicating recording conditions provided on the inner circumference side is recorded. Area WWA). That is, from the innermost circumference r ₀ of the optical disc, for example, r = 23 mm
The wobbling groove G _W, which is frequency-modulated by the data indicating the recording condition that specifies the linear velocity, the reflectance, the laser power, and the like of the disk, is formed in the area where the wobbling groove G _W is formed.

This recording wobbling area WW
In the area of radius r = 25 mm following A, the TOC information of the CD is recorded, and further, the acoustic information of the CD and the like are recorded subsequently. Such an optical disc has an advantage that an optical modulator is not needed, because only an optical deflector needs to be prepared when mastering data (when manufacturing a master).

Further, in the case of a write type optical disk formed in such a pre-format, since the condition data for writing is only the wobbling groove G _W , the recording dot information of the conventional CD is used. It can have the same pattern. In particular, the wobbling groove G _W modulated with the data of the recording condition can be easily read by, for example, a detector of the push-pull method. Therefore, if the player for recording performs tracking by the push-pull method, The present invention can be applied to an optical disc using any recording material, and the recording system can be unified.

Detecting the information of the wobbling groove even during reproduction is a system also used in the conventional optical player, and the degree of modulation of the reproduction RF signal of the concave pit information and the dot information of the recording surface. There is an advantage in that it is not necessary to consider the difference in polarity and inversion of polarity.

The wobbling groove is provided up to the TOC information area in which information is written and its outer periphery.
It is also possible to record the music information and its absolute time by the wobbling information of this portion.

Further, pit information may be put in the recording wobbled area WWA and the pit information may be read out, and the wobbling area WWA may be provided at the outermost circumference of the disc.

[0015]

According to the optical disk of the present invention, the first
Of the second data area provided on the inner circumference side of the data area, modulated based on the data read prior to the first data area, and having pits wobbled in the radial direction. Since the pits are wobbled in the radial direction in addition to the information consisting of pits in the second area, further information can be recorded.

Further, according to the optical disk reproducing method of the present invention, the data read out prior to the first data area is reproduced by the push-pull signal of the laser beam applied to the second data area of the optical disk. Therefore, it is possible to read the data recorded by wobbling the pits in the second area of the optical disc without using a special reproduction method or the like.

[Brief description of drawings]

FIG. 1 is a plan view showing an inner peripheral track portion of a write-type optical disc showing an embodiment of the present invention.

FIG. 2 is a plan view of a conventional writable optical disc.

FIG. 3 is a diagram showing an example of pits of write condition data of a write-type optical disc.

[Explanation of symbols]

WWA recording wobble area modulated by data of write condition GW wobble group

Claims (3)

[Claims] 1. A first data area in which data consisting of a plurality of pits is recorded, and data provided on the inner circumference side of the first data area and read out prior to the first data area. And a second data area having pits wobbled in the radial direction. 2. A first data area in which data consisting of a plurality of pits is recorded, and data provided on the inner circumference side of the first data area and read out prior to the first data area. And a second data area having wobbled pits in the radial direction, which is modulated according to the above method, wherein a push-pull signal of a laser beam applied to the second data area of the optical disk is used for the reproduction. A method of reproducing an optical disk, characterized in that the data read out prior to the first data area is reproduced. 3. The method of reproducing an optical disc according to claim 2, wherein the laser beam is read from the second data area before the first data area of the optical disc.