| 摘要 |
PROBLEM TO BE SOLVED: To enhance the accuracy of reading of an information reproduced signal by providing a signal processing means which has a low-pass characteristic eliminating a high frequency component from an output signal which is obtained by measuring the fluctuation quantity on the time base of the information reproduced signal and controlling an emission intensity in accordance with the magnitude of the output signal of the signal processing means. SOLUTION: After a reflected light from an optical disk 1 is converted into an electric information signal in a conversion part 4, the fluctuation quantity on the time base of the information reproduced signal is measured in a measurement part 5. At this time, a spike shaped waveform which is to be generated when an optical beam is moved to an adjacent track and a shevron waveform which is to be generated when the beam passes a reflection abnormal area are repeated every time an optical disk makes one revolution. A driving part 7 obtains an output signal in which the amplitude of the spike shaped waveform is attenuated by passing this signal through a signal processing part 6 having the low-pass characteristic to drive a light emitting part 3 so as to control the emission intensity in accordance with the magnitude of the output signal. Thus, the reduction of a reflected light quantity in the reflection abnormal area of the optical disk 1 is compensated with the increase of the emission intensity. |
