| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem of the incapability of dealing with higher speed in disk recording because of a limitation on the arithmetic operation time of a microcomputer or the effect of a delay by digital conversion for obtaining a control signal for controlling the emission output of an optical head in a conventional optical head emission output controller. <P>SOLUTION: An RF signal whose offset component is eliminated by a high pass filter 3 is limited to a fixed level by an auto-gain control circuit 4 to maintain constant an amplitude value (A+B) obtained by adding the amplitude values A and B of plus and minus sides. Further, the offset component of the RF signal is extracted by a low pass filter 5 to generate a difference value (A-B) between the amplitude values A and B of the plus and minus sides of the RF signal. Thus, an output equivalent to a β value is generated from the low pass filter 5 to control the emission output of the optical head. <P>COPYRIGHT: (C)2004,JPO |
