CIRCUIT FOR WRITING MODULATION SIGNAL TO WRITABLE OPTICAL DISC AND REGENERATING IT

摘要

PURPOSE: To simplify a circuit constitution by generating a first type pulse at first leading edges in the same way as a second type writing pulse at last trailing edges of a prescribed modulating signal. CONSTITUTION: A first pulse generator 10 generating the first writing pulse at respective first leading edges of a first format of the prescribed modulating signals and a second pulse generator 20 generating the second writing pulse at respective last trailing edges of the first format are provided. Also, a gate circuit 30, feeding one among the first or second pulse to a laser power control device with the sequence of generation so as to write the first format of modulating signals on a disk, is provided. And a signal reproducing circuit 40 which reproduces the first format of modulating signals taken out of the disk into original modulating signals and a switching circuit 50 which selects one among the second type reproducing modulation signals and the output of the signal reproducing circuit 40 to a demodulating circuit are provided. By this way, the circuit for writing/reproducing the prescribed modulation signals on the writable optical disk is obtained with the simple circuit constitution.