WRITTEN/UNWRITTEN SECTOR DECIDING METHOD FOR OPTICAL DISK DRIVING DEVICE

摘要

PURPOSE: To prevent a double writing by providing a preliminary area in the user areas of each sector and recording a specified data pattern indicating that data are already written in the area at the time of recording user data. ;CONSTITUTION: A preliminary area is provided in a block Fn and a data pattern having predetermined bits is written in the preliminary area at the time of writing data in areas DATA of an user data area DATA group. When a read instruction is issued from a host device 1, the CPU 31 of an optical disk driving device 2 reads out areas other than the preliminary area in the sector of a disk 5 with an error correction presence and reads out the preliminary area with an error non-presence. Then the CPU decides whether the sector is of a written sector or not by comparing numbers of bits of a specified code with a reference value. Thus, the acculate decision is attained.;COPYRIGHT: (C)1995,JPO