| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a reproducing method and a reproducing device which enable information reproducing of a DVD±RW with two-layer structure, which has a reflection factor only about 1/3 times a write once type DVD±R with two-layer structure, by investigating a method of reproducing DVD information. <P>SOLUTION: Signals VA, VB, VC, VD from an optical pickup device 42 are arbitrarily gain-amplified by a variable gain amplifier (VGA) 66. This gain Ginpd can be set up with directions from a CPU 53, so that it can be set up with INPDG control signals. As for focus error signals, the calculation of FE=Ginpd×[(A+C)-(B+D)] is performed by a FE arithmetic circuit 61. As for track error signals, the calculation of TE=Ginpd×[(B+C)-(A+D)] is performed by a TE arithmetic circuit 62. As for total signals, the calculation of SUM=Ginpd×(A+B+C+D) is performed by a SUM arithmetic circuit 63. A normalization circuit is constituted of an AGCCNT circuit 64 and a VCA 65. <P>COPYRIGHT: (C)2007,JPO&INPIT |
