Recording medium data recording method and device

Abstract

Provided is a data recording method, wherein if the shortest code length of the write code sequence is n (which is an integer equal to or greater than one), a write pulse waveform that has only one write pulse is assigned to recording mark making periods corresponding to codes with code lengths x of n, n + 1 and n+ 2, and a write pulse waveform that has multiple write pulses Pw is assigned to recording mark making periods corresponding to codes with code lengths x of n +3 or more. For the symbol with length of n, n + 1, when the number of the write pulse (Pw) contained in the write waveshape during the period of forming the recording mark is equal to the period number of bottom power level (Pb) between two recording pulse (Pw), the pulse width of the symbol length of m (namely the symbol length of m contained in the K-th Pb during the recording mark making period) is less than or equal to that of the symbol length of m + 1 (namely the symbol length of m + 1 contained in the K-th Pb during the recording mark making period), and the recording symbol rank is encoded by 17PP modulation encoding mode.

Description

technical field [0001] The present invention relates to a recording method and apparatus for recording data (information) by irradiating laser light on a recording medium such as an optical disc to form a mark having a physical property different from that of an unrecorded portion. Background technique [0002] A rewritable optical disk such as DVD-RAM has a phase-change recording film provided on a substrate. When the phase-change recording film is irradiated with laser light having a high energy density, the temperature of the irradiated portion locally reaches a temperature exceeding the melting point and melts. Since the optical disc irradiated with laser light rotates at high speed, the beam spot of the laser light moves at high speed along the track on the phase change recording film. Therefore, the portion of the phase-change recording film that was melted by the passage of the beam spot immediately cools naturally and solidifies. By adjusting the power of the laser...

AI Technical Summary

Problems solved by technology

Therefore, in the phase-change recording medium, there is an advantage that it is easy to share the reproducing device with the phase-pit type recording medium, but there is no such deformation in the reproduced signal from the phase-pit type recording medium, so based on the phase-pit type recording medium Reproduction with the same device becomes difficult

[0017] In addition, in the above-mentioned fourth conventional technique, the recording power level of the recording pulse train changes stepwise, so complicated power control is required.

In addition, when recording a signal with a symbol length of 4Tw, light is emitted at a power level higher than the average power level of at least 3Tw, and the density becomes high. Disadvantages of required record marking

[0018] According to the above-mentioned prior arts, marks cannot be formed with sufficient accuracy at high transfer speeds, and as a result, sufficient recording area density and reliability cannot be achieved.

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