| 摘要 |
PURPOSE:To obtain accurate information in reproduction of the data recorded on an optical disc by providing specific phase detecting pattern, investigating n-pieces of phase information among the same and detecting the coincidence of >=m-pieces (m<n) with the prescribed pattern. CONSTITUTION:A read-out signal outputs the pulse 61 corresponding to 1 with a peak detecting circuit. If there is no error in the pulse 61, a coincidence signal is generated at every 4 bits from all decoders 74. When an error is included in the pulse 61, no coincidence signal is produced in the decoder output in the error part even if the timing is normal. The decorder 74 are conducted to a majority decision circuit 75 and when the coincidence output attains a prescribed number or above, an output 71 is generated therefrom. The output 71 determines the state of an FF 82 through the gate signal 63 applied to an AND gate 84. Thus the many bits are referenced simultaneously without concentrating the information at specific one bit; therefore, even if the error is included, the correct detection signal is obtained by eliminating the influence thereof and the correct information is obtained. |
