| 摘要 |
PURPOSE:To obtain a ROM-RAM coexisting disk with a low cost by prov.iding a part of a ROM disk with a RAM part which is easily formable to a small capacity and reproducing this region with the same optical system as for the ROM disk. CONSTITUTION:The disk 1 consists of the ordinary ROM part 11 of the outer peripheral part and the recordable RAM part 12 stuck with thermosensitive paper on the inner periphery. At the time of recording, an exothermic head 3 is brought contact with a thermo-sensitive paper part 12. At this time, recording currents are passed to the head 3 according to information to change the thermosensitive paper by heat and to execute recording with the black and white information. Reading out of the data recorded on the thermosensitive paper is executed by using an optical head 2. The head 2 moves to the RAM part 12 of the thermosensitive paper at the time of data reading out of this part. The data is thereafter read out by return light of a semiconductor laser. At this time, servo is not applied to both of focusing and tracking. A specified voltage is applied to a focus actuator to adjust the focus position so as to bring this position approximately to the plane of the thermosensitive paper. |
