Information recording medium, information recording method and information recording apparatus
AssigneesHitachi, Ltd., Hitachi Maxell, Ltd.
InventorsYasushi Miyauchi, Motoyasu Terao, Akemi Hirotsune, Hiroyuki Minemura, Harukazu Miyamoto
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Abstract
A recording medium having a dummy signal area on at least one side of a recording area is used and information is recorded with a dummy signal added to at least one of the leading and trailing sides in the recorded information signal. The user data area remains unaffected by repeated overwriting so that recorded user data is reproduced correctly. In particular, the wave form distortion caused by fluidization of a recording film remains at the dummy signal area and does not affect the user data area, so that the reproduction of the target information (user data) is assured.
Claims6
An information recording apparatus for recording information by energy beam irradiation, comprising:
- a laser beam source for producing a laser beam;
- a laser driver to drive the laser beam;
- a recording waveform generator to generate the recording waveform;
- means for recording a recording signal and a dummy signal added to at least a leading or trailing side of the recording signal,
- wherein the length of said trailing side dummy signal is longer than that of said leading side dummy signal,
- wherein a duty ratio of the dummy signal is not greater than 50%,
- and wherein a recording start position of a combined recording signal and dummy signal is shifted at random;
- and
- means for adding a postamble pattern after a user data.
Dependencies are inferred from the claim text.