Boundary detection apparatus, information recording medium as well as the boundary detection and a program for boundary detection method

摘要

Even when there is eccentricity in the CD itself or if there are missing due to deposits and scratch the recording surface of the CD, to provide a boundary detecting apparatus which can detect the end of the recorded area quickly and reliably. When the information is recorded in the dividing position B set in advance is detected, to move the pickup to the divided position C that lies ahead as viewed from the dividing position B after the movement, on the other hand, information in the dividing position B When it There is not recorded is detected, to move the pickup to the divided position A in the opposite direction from the dividing position B, further, the end and moves the pickup further after determining the existence range of terminating the final to detect.