Patent ID: 6212145
Filing Date: 2001-04-03
Classification: G11B

Abstract:
An optical disk device for recording on and reproducing from an optical disk having information recording tracks formed of concentric or spiral first-type recording regions formed about an axis of rotation, and second-type recording regions between the first-type recording regions, each said track corresponding to one revolution of the disk and being provided with sectors, each sector having an identification information part shifted in the radial direction of the disk,the disk being configured such that when a first sector in a first track is being scanned, an identification information part of the first sector and an identification information part of a second sector in a second track adjacent to said first track are both scanned, andone of the identification information part of the first sector and the identification information part of the second sector being disposed first and the other being disposed second with respect to the order of scanning,said optical disk device comprising:means for reading a first address from the identification information part of the first sector and a second address from the identification information part of the second sector when the first sector in the first track is scanned, the address from an identification information part scanned first having either a higher or lower value than the address from an identification information part scanned second, depending on whether the first track is formed by a first-type recording region or a second-type recording region;means for comparing the magnitudes of the address from an identification information part scanned first and the address from an identification information part scanned second; andjudging means for judging whether the track being scanned is formed by the first-type recording region or the second-type recording region in accordance with the result of the comparison, said judging means determining that the track being scanned is formed by the first-type recording region when the address from an identification information part scanned first is greater than the address from an identification information part scanned second, and that the track being scanned is formed by the second-type recording region when the address from an identification information part scanned second is greater than the address from an identification information part scanned first.