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.
Claims2
An information recording method in which information is recorded on a recording medium by means of energy beam irradiation, comprising recording with a laser beam a dummy signal added to at least one of the leading and trailing sides in the recording signal,
- wherein a position where the recording of the signal including the dummy signal starts is shifted at random,
- wherein the maxi m shift width of the recording start portion is shorter th n the length of the dummy signal,
- and wherein a duty ratio of the dummy signal is not greater than 50%.
Dependencies are inferred from the claim text.