| 摘要 |
PURPOSE:To decrease mis-recording by deciding the size of prebits while tracking a prebit row by a single optical beam and forming bits corresponding to recording information between the prebits only when they are of the preset size. CONSTITUTION:The system is so constituted that the optical refletion from an optical disc 1 by reproduced optical beam is conducted to a photoelectric transducer 18, where it is photoelectrically converted to an electric signal. This electric signal is amplified with an amplifier 19, after which it is coded into a binary code by a binary coding circuit 20. This binary coded signal is supplied to a monostable multi 21. The output of the above-mentioned monostable multi 21 is supplied together with the output of the circuit 20 to an EF circuit 22. The circuit 22 decides the size of prebits 3 at the timing of the rising edge of the binary coded signal. Thereby, the formation of bits in the defect parts 5, 6 of the optical disc is prevented, hence mis-recording is considerably decreased. |
