Patent ID: 6278671
Filing Date: 2001-08-21
Classification: G06K,G11B

Abstract:
An optical disk comprising:a first recording area where main information is recorded,a second recording area where barcode-like marks, each of which has a strip-like configuration in a radius direction and which are disposed in a circumferential direction, are recorded as a sub information;wherein said first recording area contains at least a lead-in area from which data recording starts, and a control data area which represents a physical property of the optical disk;said second recording area is disposed inside said control data area on said first recording area and said second recording area is overlapped with the said lead-in area;said sub information is PE-modulated to be further RZ-modulated to be recorded on said second recording area so that a width of said barcode-like marks is half or less than a period of said barcode-like marks, andthere is a guard band area on which at least an address is recorded, between at least a portion of said control data area and the second recording area.