Title:
OPTICAL CARD
Document Type and Number:
Japanese Patent JPH04137267
Kind Code:
A
Abstract:
PURPOSE:To obtain the optical card capable of logical erasure without reducing an area where real data are recorded by providing plural sectors which differ in size in a track and recording erasure information in at least one sector of small size. CONSTITUTION:A track 2 which is not provided with a prerecord area for dividing the data recording area into plural sectors is included, the two sectors 4a and 4b which differ in size are provided in this track 2, and the erasure information is recorded at least in one sector 4b which is smaller in size be tween those sectors 4a and 4b. A blank area which is not used for data record ing because of a difference of format is formatted differently to matching sector size and used as an area where the erasure information is recorded. Consequent ly, the logical erasure becomes possible without reducing the area where actual data are recorded.
Inventors:
OSHIBA MITSUO
Application Number:
JP25710790A
Publication Date:
May 12, 1992
Filing Date:
September 28, 1990
Export Citation:
Assignee:
OLYMPUS OPTICAL CO
International Classes:
G11B20/12; G11B7/00; G11B7/0033; G11B7/0055; G11B27/10; (IPC1-7): G11B7/00; G11B20/12; G11B27/10
Attorney, Agent or Firm:
Atsushi Tsuboi (2 outside)