| 摘要 |
PURPOSE: To reproduce plural bits of information from a pit among the pits provided with plural depths. CONSTITUTION: A laser emits a beam by which an optical disk is irradiated. The beam reflected by the optical disk is received by a photodetector. A read signal generation part, a multilevel converter and a parallel/serial converter are connected in order. The generation part generates a read signal taking 2N pieces of levels corresponding to the light quantity of the received beam. The read signal is converted to a code data signal of N bits by the multilevel converter, and is converted to a regenerative serial data signal by the parallel/ serial converter. Thus, the recording density of the optical disk is increased. |
