| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent error rate deterioration at reproduction time even if a photodetector with a poor characteristic is included. Ž<P>SOLUTION: An optical pickup unit 3 includes 4 photodetectors. A controller 13 obtains an error correction result of a reproduced signal, which is reproduced based on an RF signal generated while changing a combination of 4 photodetectors at startup time, and determines a combination at reproduction time in accordance with the obtained error correction result for giving it to an RF amplifier unit 10. The controller 13 includes: a counter that counts an error correction result for a fixed time period for each combination of photodetectors, a comparator that compares a count result of the counter with a preset threshold, and an output controller that determines whether or not to use the combination of photodetectors based on a comparison result of the comparator and performs change control to a plurality of combinations of photodetectors. At reproduction time, control is performed to obtain the reproduced signal from by other than the photodetector with the poor characteristic. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
