| 摘要 |
PROBLEM TO BE SOLVED: To provide a recorder for information recording medium which can obtain good reproduction information both from a reproduction-dedicated pit string and from a guide groove for recording/reproducing and can obtain optimum tracking characteristics at all times even in an unrecorded region as well as in a recorded region, by reproducing the intermediate area consisting of the pit rows by a tracking system of a differential push-pull system or a differential phase detect system. SOLUTION: The method employs an information recording medium in which bottom surface positions of the guide grooves and the pit rows formed on a disk substrate are both flat on a same plane, and an intermediate region consisting of pit rows is provided where the height from the bottom surfaces to the side surfaces of the grooves and the height from the bottom surface to the side surfaces of the pit rows vary at the portions changing-over from the pit rows to the guide grooves and vice versa. |
