Patent ID: 6128256
Filing Date: 2000-10-03
Classification: G11B

Abstract:
An apparatus for recording data on, or reproducing data from, a disk shaped recording medium, wherein the recording medium has a first pre-group and a second pre-group, wherein at least one of the pre-groups has encoded address information shared by at least one inner circumferential track on an inner circumferential side of the pre-group and shared by at least one inner circumferential side of the pre-group and shared by at least one outer circumferential track on an outer circumferential side of the pre-group, the apparatus further comprising:optical head means for tracing a predetermined track and for reproducing data from the disk shaped recording medium;decoding means for decoding address information included with the reproduced data;access control means for controlling the optical head when accessing a desired track; andcomparison means for comparing an address decoded before accessing and an address decoded after accessing;judgment means for judging whether the optical head has accessed the desired track.