Patent ID: 6101159
Filing Date: 2000-08-08
Classification: G11B

Abstract:
A method for obtaining a first pulse position Tu for a data recording medium havinga plurality of tracks,marks formed by emitting to a track in the data recording medium an optical beam modulated by one or a plurality of drive pulses where a number of the drive pulses is determined according to a length of a mark part in the original signal to be recorded to the track,a data recording area for recording information using the marks and spaces between the marks, anda control information recording area having recorded thereto at least a first pulse position Tu value whereby a first pulse position Tu of the drive pulse is changed so as to make a reproduction jitter a specific value or less,said method comprising:generating a pattern signal containing a pattern of consecutive mark parts with a specific length of PT and space parts with a specific length of QT where T is a reference period, P is a positive integer from n1 to n2, and Q is a positive integer from n1 to n2;storing the pattern signal;generating a plurality of drive pulses from the pattern signal;forming spaces and marks on the data recording medium by generating and emitting thereto an optical beam modulated according to the plurality of drive pulses;reproducing the marks and spaces recorded to the data recording medium;comparing and obtaining a difference between a combination of mark and space parts in the reproduced reproduction signal, and a combination of mark and space parts in the stored pattern signal; andobtaining from this difference a first pulse position Tu for application to an original signal containing a sequence of space parts of length QT and mark parts of length PT said first pulse position Tu being obtained relative to a type of the recording medium.