| 摘要 |
PURPOSE:To obtain equal output signals at all track positions by rotating a recording and a reproducing disk at a constant angular speed and equalizing recording signals in dot length at an inner and an outer peripheral part. CONSTITUTION:When a data signal 1 is inputted, the address signal 2 of a recording track is detected and a frequency converter 3 selects the frequency of the track position corresponding to the signal 2 among f1-fn to convert a carrier signal frequency. Modulation is imposed upon a semiconductor laser 4 by using the converted signal to generate laser pulse light 5, which illuminates a rotary disk. Consequently, conversion for increasing the carrier signal frequency is performed at outer peripheral tracks for the innermost periphery to reduce the with of the laser pulses, thereby equalizing the recording dot length of the innermost periphery to that of the outermost periphery. The peak power of the laser light at the outer periphery is set high corresponding to track positions to equalize thermal variation of recording dots. |
