Patent ID: 6128260
Filing Date: 2000-10-03
Classification: G11B

Abstract:
An information recording medium on/from which information is recorded/reproduced in units of sectors each having at least a header field on which address information is recorded in advance and a recording field arranged next to said header field, using a change in optical characteristics due to a phase change, said recording field comprising:an actual recording field on which information is rewritably recorded;a first nonrecording field arranged before said actual recording field and having a length based on a first random number to prevent interference between said header field and said actual recording field, wherein a recording start position of said actual recording field is set at random; anda second nonrecording field arranged next to said actual recording field and having a length based on the first random number, and a sum of the lengths of said first and second nonrecording fields is always constant,wherein said actual recording field includes a first dummy data field arranged at a start of said actual recording field and having a predetermined length, said first dummy data field recording dummy information which need not be properly reproduced.