| 摘要 |
<P>PROBLEM TO BE SOLVED: To make compatible outgoing light quantity control of a laser diode and highly accurate elimination of laser noise. <P>SOLUTION: In an optical disk device 130, outgoing light quantity control of a laser diode 62 is performed, while light quantity of a light beam L2 irradiated to the optical disk 100 can be kept constant by performing outgoing light quantity control by performing grating position control of a variable diffraction grating 66 by a light quantity control part 140 so that a signal level of a high-order light high frequency band signal VbcH is adjusted to a signal level of a reproduced RF signal SRF during playback of the optical disk 100, while diffraction efficiency of the 0-order light and the high-order light emitted from the variable diffraction grating 66 is changed appropriately, a laser noise component can be eliminated by only that the high-order light high frequency band signal VbcH is subtracted directly from the reproduced RF signal SRF. <P>COPYRIGHT: (C)2009,JPO&INPIT |
