| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical disk device which eliminates the noise of laser beams modulated by the pit of an optical disk from reproduced signals. <P>SOLUTION: While the optical disk D is irradiated by emitting the laser beam from a semiconductor laser 2 and return light from the optical disk D is detected in a photodetector 7 and photoelectrically converted to generate reproduced signals, the laser beam is detected in a photodetector 10 and photoelectrically converted to generate electric signals, and APC signals for controlling the output of the laser beam are generated from the electric signals in an APC control circuit 12. The optical disk device is provided with: a high-pass filter 13 for eliminating low frequency components included in the APC signals, passing only high frequency components through and generating high frequency APC signals; a multiplier 14 for multiplying the high frequency APC signals by the reproduced signals and generating multiplied signals; and a differential amplifier circuit 15 for calculating a difference between the reproduced signals and the multiplied signals and generating noise-eliminated signals. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
