Recording medium, recording apparatus and recording method

Abstract

Optimum movement of first and last signal pulses based on the data pattern is determined before data recording to record marks in the correct position. A specific pattern signal is read from a disc track and digitized with an appropriate slice level by the digitizing circuit (115). A pulse position offset measuring circuit (120) then measures specific edge intervals in the resulting digital signal. Movement of the first and last pulse by the pulse moving circuit (110) is then set so that the offset between the measured edge interval and a predetermined standard edge interval is ideally zero.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a data recording medium, a recording apparatus and to a recording method for recording information to this data recording medium.

[0003] 2. Description of Related Art

[0004] Data recording devices for optically recording information, and particularly digital data, to a storage medium are commonly used as a convenient means of mass data storage.

[0005] Phase change optical discs are one type of optical data recording medium. To record to a phase change optical disc a semiconductor laser emits an optical beam to a spinning disc to heat and melt a recording film on the disc. The achieved temperature and the cooling process (rate) of the molten film can be regulated by controlling the power of the laser beam, thereby inducing a phase change in the recording film.

[0006] When laser power is high, the recording film cools rapidly from a high temperature state and thus becomes amorphous. Wh...

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