JPH06176368A - Optical disc and its recording method and device - Google Patents

Abstract

(57) [Summary] (Correction) [Structure] Information (reference signal) such as laser power, pulse width, modulation method, and reference recording magnetic domain necessary for recording on the optical disc is set in advance on the optical disc. Record in the area. The optical disk recording apparatus is provided with a circuit for reproducing a reference signal, a circuit for test recording (test writing), and a circuit for comparing and discriminating a test recording result with a reference signal. [Effect] It is possible to always record under optimal conditions on optical discs having different laminated structures of optical discs and different physical properties of materials used, and high-density recording is realized, as well as between optical discs and an optical disc drive device. Compatibility between the two can be secured. In addition to the recording conditions, the difference in the modulation method and the recording density (for example, bit density) can be detected, and the compatibility of the optical disks can be further secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording technology for recording, reproducing or erasing using at least a laser beam, and more particularly to an optical disk suitable for ensuring compatibility between optical disks and disk drive devices. The recording method and apparatus are related.

[0002]

2. Description of the Related Art In recent years, the need for a high-density and large-capacity file memory has increased with the progress of an advanced information society. Optical recording technology has been attracting attention as a response to this. Among them, rewritable magneto-optical disks are applied to document files, image files, etc., including code data recording. At present, research and development are being actively pursued with the aim of achieving higher performance, such as further improvement in recording density. Incidentally, an optical disk is a replaceable recording medium unlike a magnetic disk. Therefore, it is currently determined by the standard such as JIS that recording conditions such as laser power and pulse width are recorded in a predetermined area on the optical disc.

[0003]

In order to increase the capacity of an optical disc, a method of increasing the bit density such as a zone CAV method or a mark length recording method, and a method of reducing the track pitch such as a crosstalk canceller are proposed. Has been done. However, with these techniques, although high-density recording is possible under constant optical disk characteristics, there is a problem in that compatibility between optical disk characteristics, particularly disks having different thermal characteristics, cannot be ensured.

An object of the present invention is to solve the above problems in the prior art and to apply the above-mentioned high density technology,
By providing a method that can always record under the optimum recording conditions of optical discs, while ensuring ultra-high density optical recording, ensuring compatibility between various optical discs and disc drive devices, An object of the present invention is to provide a high optical disc and a recording method and apparatus for the same.

[0005]

In order to solve the above-mentioned problems of the present invention, at least in an optical disc for recording, reproducing or erasing by using a laser beam, recording or reproducing of the optical disc in a preset area on the optical disc in advance. Alternatively, a reference signal for determining the optimum erasing condition is recorded and environmental conditions such as when the optical disc is mounted in the disc drive (disc drive), when the disc drive is started up, and the external temperature surrounding the disc drive. When a change occurs, a reference signal previously recorded on the optical disc is reproduced, and the reproduction signal is used to determine the optimum condition for recording, reproducing or erasing the optical disc. Here, the information (reference signal) to be recorded in advance in the set area on the optical disc is the reference of the modulation system of the reproduction signal or the recording system of the optical disc, such as laser power and pulse width for recording, reproduction or erasing. It is a signal. Here, only by recording the laser power, pulse width, etc. as numerical values on a predetermined track, the spot shape of the light beam of the disk drive used, the reproduction circuit, etc. may differ, and the optical characteristics of the optical disk may be different. However, it was difficult to control the shape of the recording domain with high accuracy. Therefore, it is effective to record the standard recording domain as the reference signal to be recorded in the set area on the optical disc in advance in order to ensure the compatibility of the optical disc. That is, the reference signal is used to control the recording conditions so that the same signal as in the standard recording domain can be obtained. Here, the condition to be provided as the reference signal is that the recording domain length reflects the modulation method and the magnetic domain width determined in consideration of the erasing condition, the format of the track offset disc, etc. is there. For example, it can be obtained by recording and reproducing three kinds of signals recorded under standard conditions (room temperature, laser power, pulse width, etc.) and when deviated by about ± 10% around the conditions. The reproduced signal can be used as a reference signal. By comparing and discriminating this reproduction signal with the signal obtained by reproducing the information written by trial writing (test recording) performed before recording or erasing, the laser power and pulse width of the recording are always optimized. Can be set as: Needless to say, the above test recording needs to be performed at regular time intervals. Alternatively, it is possible to determine the optimum conditions such as laser power for recording or erasing by reproducing the reference signal recorded in the set area on the optical disc in advance before recording information on the optical disc. . In addition to this, a reference signal previously recorded in a set area on the optical disc may be reproduced before recording information on the optical disc, and this reproduced signal may be used as a reference clock signal for recording or erasing. Furthermore, in the case of an optical disc that is divided into a plurality of recording zones by a recording method that makes the recording density almost constant at any position on the optical disc, at least each reference signal recorded in advance on the optical disc is For recording or reproducing or erasing on the basis of this reproduction signal, the information is recorded in an area set for each recording zone or a representative recording zone and reproduced before recording, reproducing or erasing information on the optical disc. Optimal conditions can be determined. Further, even when an optical disc of a recording system in which information is recorded on the edge portion of the recording magnetic domain is used, the reference signal previously recorded in the set area on the optical disc is recorded, reproduced or erased on the optical disc. Before reproduction, the optimum conditions for recording or reproducing or erasing can be determined based on the reproduction. The reference signal recorded in advance on the optical disc is normally stored (recorded) when the optical disc is shipped.

[0006]

A predetermined reference signal serving as a reference for recording, reproducing or erasing the optical disc is recorded in advance in a set area on the optical disc, and test recording (trial recording) before recording information based on the reference signal is performed. By performing drive operations such as writing) and confirmation (verification) after recording information,
By providing a function of detecting a difference from the reference signal and finding an optimum recording condition from the result, compatibility between optical disk media and optical disk recording devices can be secured. In the present invention, the optimum recording, reproducing or erasing condition can be searched for based on the reference signal pre-recorded on the optical disc, so that the difference in the laminated structure of the optical disc medium (corresponding to the difference in the thermal structure). Even if there is a difference in various characteristics of the optical disc due to such reasons, the compatibility of the optical disc and the optical recording device can be ensured by using the optical disc of the present invention and the recording method and device thereof.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in more detail with reference to the drawings. An overall view of the optical disk used in this example and a cross-sectional structure structure of a main part are schematically shown in FIGS. 1 (a) and 1 (b). The optical disc was manufactured by the sputtering method. As shown in FIG. 1B, a silicon nitride layer 2 having a thickness of 75 nm was formed as an inorganic dielectric layer on a disk substrate 1 having an uneven guide groove (not shown). Then, the magneto-optical recording film 3 made of TbFeCoNb 3
Was formed to a film thickness of 25 nm, and then the silicon nitride layer 4 was formed again to a film thickness of 20 nm as an inorganic dielectric layer. Then, finally, an Al ₉₀ Ti ₁₀ layer was formed as the metal layer 5 to obtain an optical disc. The structure of the optical disc manufactured in this example is an example,
The present invention can always record under optimum conditions without depending on the structure of the optical disc, and is not limited to the optical disc structure of this embodiment. Using the recording waveform having the shape shown in FIG. 2, an optimum recording shown below at 25 ° C. in a control track area provided on the outermost circumference and / or the innermost circumference of the optical disk. It was recorded beforehand using the conditions. The power level of the above recording waveform has four levels. The laser power level at the innermost position is the standard level, and from the lower level,
The read level (Pr), the preheat level (Pas), the first recording level (Pw ₁ ) and the second recording level (Pw ₂ ) are included. The value of each level is
In the optical disc manufactured in this example, Pr
= 1.5mW, Pas = 2.50mW, Pw 1 = 4.
It was 75 mW and Pw ₂ = 5.10 mW. The width of each pulse of the recording waveform is α = 60 ns, β = 20n
s, γ = 20 ns, and δ = 40 ns. here,
The pulse widths α, β, γ, δ and the levels of the four laser powers differ depending on the laminated structure of the optical disc and the material used, and are values that vary depending on the optical disc. The recording was performed by using the zone CAV method so that the recording density was constant at any position on the optical disc. In addition, the recording density was improved by using the mark length recording method. As the modulation method, the (1,7) RLL method was used. By the way, if the (1,7) RLL method is used,
The shortest bit length (1.33T) is 0.75 μm and the longest pit length (5.33T) is 3.0 μm. The pattern in the meantime was determined by extrapolation from 1.33T and 5.33T. Here, as standard information (reference signal) to be recorded on the optical disk in advance, the power value and pulse width of each of the four laser power levels at 25 ° C., and the reproduction signal modulation method uses (1, 7) modulation. And the repetition of the shortest bit length (1.33T) and the shortest gap (1.33T) in the above (1,7) modulation, the longest pit (5.33T) and the longest gap (5.33T). ) And repeated. further,
Pw ₂ / Pas and Pw _{1 in} repetition of the shortest pattern
Pw ₁ and Pw ₂ while keeping the ratio of / Pas constant.
Each power of ± 0.2mW from the reference value up to ± 0.6
A pattern was recorded that was continuously varied up to mW.

FIG. 3 shows an example of the configuration of the optical disk recording apparatus used. As shown in the figure, the characteristic feature of the optical disc recording apparatus of the present invention is that the conventional optical disc recording apparatus is
A circuit for reproducing standard information (reference signal) previously recorded in the setting area of the optical disc, a circuit for test recording (test writing) by a test writer, the above test recording result, and the above reference It suffices to have at least a circuit for comparing and discriminating a signal with a comparing and discriminating device and discriminating an optimum recording, reproducing or erasing condition, and other portions are almost the same as the configuration of the conventional optical disc recording apparatus.
Then, the magneto-optical disk drive of the optical disk recording apparatus shown in FIG. 3 was held in an environment of 50 ° C. The reference signal was reproduced at regular time intervals before the desired information was recorded on the optical disk and immediately after the optical disk was loaded (mounted) in the disk drive. Then, recording was performed with the standard power recorded on the optical disc. The recording result and the powers of Pw ₁ and Pw ₂ pre-recorded on the optical disc are changed and compared with the recorded pattern to judge whether the recorded power is optimum, overpower or insufficient. did. If it is determined that the power is overpower or insufficient, set the power low or high respectively and change the power up and down around the set value to perform the optimum recording. When I searched for power, 1-2
The optimum power could be set by repeating the operation once. Even when the environmental temperature was low, the optimum recording power could be found by the same operation as above. Next, although the structure of the optical disk is unknown, an optical disk in which the above-mentioned reference signal previously recorded in the optical disk is recorded at the set position of the optical disk was used. Immediately after loading the optical disc into the disc drive or immediately before recording or erasing the optical disc, a reference signal previously recorded on the optical disc was reproduced and used as a reference power. Next, before recording information on the optical disc, test recording is performed based on the reference signal recorded on the optical disc, and the result is compared with the result of the reference signal recorded as the reference to determine the recording power. Optimized. As a result, it was possible to record under the optimum conditions. In addition to recording, it is possible to detect a difference in modulation method and recording density (for example, bit density). Therefore, even for optical disks having different modulation methods and recording densities, if a corresponding recording-reproducing circuit is provided. , Compatibility between optical disks can be achieved. At the same time, various conditions such as modulation method, recording and erasing power, pulse width, and temperature coefficient of power are recorded in a predetermined area of the disc,
By using these together, compatibility between optical disks can be further ensured. In this method, a domain having a shape that reflects the modulation method to be used, a temperature change is defined and a recording domain is recorded in advance, and this is used as a reference signal.

[0009]

As described in detail above, according to the optical disc and the recording method thereof of the present invention, the optimum condition is always maintained even for the optical disc in which the laminated structure of the optical disc and the physical properties of the materials used are different. Can be recorded. As a result, high density recording can be realized, and compatibility between optical disks and disk drive devices can be ensured. Further, in addition to the recording conditions, it is possible to detect the difference in the modulation method and the recording density (for example, the bit density), so that the compatibility of the optical disks can be further secured.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an overall structure and a sectional structure of an optical disc exemplified in an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of the form of a recording waveform shown in the embodiment of the present invention.

FIG. 3 is a schematic diagram showing an example of the configuration of the magneto-optical disk drive shown in the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disk substrate 2 ... Silicon nitride layer 3 ... Magneto-optical recording film (TbFeCoNb) 4 ... Silicon nitride layer 5 ... Metal layer 6 ... Magneto-optical disk 7, 8 ... Control track 9, 10 ... Recording domain (reference signal) 11 ... Optical head 12 ... Light receiver 13 ... Reproduction amplifier 14 ... Waveform equalizer 15 ... Input switcher 16 ... Shaper 17 ... PLL (Phase-locked loop circuit) 18 ... Discriminator 19 ... Decoder 20 ... Laser 21 ... Laser driver 22 ... APC (Automatic Phase Controller) 23 ... Recording Waveform Generator 24 ... Encoder 25 ... Trial Writer 26 ... Comparison Discriminator

Claims (15)

[Claims] 1. An optical disc for recording, reproducing or erasing at least using a laser beam, and a reference signal for determining an optimum condition for recording, reproducing or erasing the optical disc in a preset area on the optical disc in advance. An optical disc characterized by being recorded. 2. A reference signal according to claim 1, which is pre-recorded in a set area on the optical disc, is a reference signal relating to a laser power and a pulse width, a reproduction signal modulation system or an optical disc recording system. optical disk. 3. The reference signal recorded in advance in a setting area on the optical disk according to claim 1 or 2,
± 1 centered on the standard condition and the standard condition
An optical disc having at least three types of signals when they are deviated by about 0%. 4. The reference signal according to any one of claims 1 to 3, wherein the reference signal previously recorded in a setting area on the optical disk is recorded in a control area of a control track of the optical disk. optical disk. 5. The optical disc according to any one of claims 1 to 4, wherein the optical disc is divided into a plurality of recording zones by a recording method in which a recording density is substantially constant at any position on the disc. An optical disc in which an optical disc is recorded on the optical disc in advance, and the reference signal is recorded in each of the recording zones or in a region of a typical recording zone. 6. The optical disc according to any one of claims 1 to 4, wherein the optical disc uses a recording system for recording information in the length of a recording magnetic domain, and the optical disc is set in a set area on the optical disc. An optical disc having a reference signal recorded therein. 7. An optical disk recording method for recording, reproducing or erasing using at least a laser beam, wherein the optical disk according to any one of claims 1 to 6 is used, and when an optical disk disk drive is mounted, When the disc drive is started or when the external environment temperature surrounding the disc drive changes, the reference signal recorded on the optical disc is reproduced, and the reproduction signal is used to determine the optimum condition for recording, reproducing or erasing the optical disc. A method for recording an optical disc, comprising: 8. The optical disc according to claim 7, wherein the optical disc according to any one of claims 1 to 6 is used, and a reference signal recorded in advance in a setting area on the optical disc is recorded with information on the optical disc. A recording method for an optical disk, characterized in that the optimum condition for recording or reproducing or erasing is determined based on the reproduction signal before reproduction. 9. The optical disc according to claim 7, wherein the optical disc according to any one of claims 1 to 6 is used, and a reference signal previously recorded in a setting area on the optical disc is recorded with information on the optical disc. A method for recording an optical disk, characterized in that reproduction is performed at least once before reproduction or erasing, and an optimum condition for recording, reproduction or erasing is determined based on the reproduction signal. 10. The optical disc according to claim 7, wherein the optical disc according to any one of claims 1 to 6 is used to record a reference signal previously recorded in a set area on the optical disc with information on the optical disc. A recording method for an optical disc, characterized in that the reproduction signal is reproduced before the reproduction, and the reproduction signal is used as a reference clock signal when recording or erasing information. 11. An optical disk recording apparatus in which the optical disk according to any one of claims 1 to 6 is mounted in a disk drive and at least information is recorded, reproduced or erased by using a laser beam, When the disc drive of the optical disc is installed, when the disc drive is started,
Alternatively, at least a means for reproducing the reference signal recorded on the optical disk when the external environment temperature surrounding the disk drive changes and a means for determining the optimum recording condition of the optical disk by using the reproduction signal are provided. Optical disc recording device. 12. The optical disc according to claim 11, wherein the optical disc according to any one of claims 1 to 6 is mounted in a disc drive, and a reference signal recorded in advance in a setting area on the optical disc is recorded on the optical disc. An apparatus for recording an optical disk, comprising: a means for reproducing the information before recording the information on the disk; and a means for judging an optimum condition for recording or reproducing or erasing based on the reproduction signal. 13. The optical disc according to claim 11, wherein the optical disc according to any one of claims 1 to 6 is mounted in a disc drive, and a reference signal recorded in advance in a setting area on the optical disc is recorded on the optical disc. Record the information in,
An optical disk recording apparatus comprising: a means for reproducing at least once before reproduction or erasing; and means for judging an optimum condition for recording, reproducing or erasing based on the reproduction signal. 14. The optical disc according to claim 11, wherein the optical disc according to any one of claims 1 to 6 is mounted on a disc drive, and a reference signal recorded in advance in a setting area on the optical disc is recorded on the optical disc. An optical disk recording apparatus comprising: a means for reproducing the information before recording the information on the disk; and a means for using the reproduction signal as a reference clock signal at the time of recording or erasing the information. 15. The method according to any one of claims 11 to 14.
An optical disc recording apparatus according to claim 1, wherein the optical disc according to any one of claims 1 to 6 is mounted in a disc drive, and a reference signal recorded in advance in a setting area on the optical disc is recorded on the optical disc. A recording device for an optical disc, comprising: a means for reproducing before recording information on the optical disk; and a means for judging an optimum condition for recording or reproducing or erasing based on the reproduction signal,
A circuit for reproducing the reference signal recorded in the preset area on the optical disc, a test recording circuit for trial writing, and a comparison / discrimination circuit for comparing the test recording result with the reference signal to determine the optimum condition. An optical disk recording apparatus comprising at least the following.