Optical disk with a non-volatile memory, optical disk unit, and control method for the optical disk unit

Abstract

An optical disk is provided including a read only memory region formed on one surface of the optical disk and recorded with information, a non-volatile memory formed on the other surface of the optical disk opposite to the surface formed with the read only memory region, a mark formed on the surface of the optical disk where the non-volatile memory is formed, and one or more dummy memories arranged on the optical disk in such a manner that the center of weight of the optical disk is positioned at the center of the optical disk. Also, provided is an optical disk unit adapted to use the optical disk, which includes a non-volatile memory pickup unit for reading data recorded on the non-volatile memory of the optical disk and writing data onto the non-volatile memory. The optical disk unit is controlled by applying a write or read command to the non-volatile memory, sensing the mark on the optical disk, stopping the optical disk, electrically connecting the pickup to the non-volatile memory, executing a data reading or writing operation for the non-volatile memory, and electrically disconnecting the pickup from the non-volatile memory. Additionally, there is further provided an optical disk unit for a cartridge type optical disk, with at least one non-volatile memory formed on one surface of the cartridge.