| 摘要 |
<P>PROBLEM TO BE SOLVED: To complete highly precise calibration in a short period of time. <P>SOLUTION: A disk driver 1 decodes reproduced signals being reproduced from an optical disk 100 by a Viterbi decoding method. The disk driver 1 includes an analog signal processor 16 which is used to obtain light receiving signals SD from an optical pickup 5, that is used to irradiate laser light beams L1 to the optical disk 100 and to detect reflected laser light beams L2, and generate reproduced RF signals, a Viterbi decoder 25A which is used to generate state data that express state transition itself in Viterbi decoding, a quality index generator 25B which is used to compute the difference between an amplitude reference value corresponding to the state transition recognized from the state data and a reproduced signal value that is obtained by A/D converting the reproduced RF signals and express superiority or inferiority of the quality of the reproduced RF signals on the basis of the difference and a CPU2 which is used to conduct calibration of the optical pickup 5 on the basis of a quality index value CQ. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
