| 摘要 |
<P>PROBLEM TO BE SOLVED: To continuously perform layer-switching reproduction by performing focus jump to a recording and reproducing objective layer of a disk medium having a plurality of layers at high speed. <P>SOLUTION: This device is provided with a first optical system equipped with a semiconductor laser 41 and a photodetector 44 to perform signal recording and reproducing on the L0 layer of an optical disk medium 80, and a second optical system equipped with a semiconductor laser 51 and a photodetector 54 to perform signal recording and reproducing on the L1 layer of the optical disk medium 80. The focus jump is performed between the L0 and L1 layers by switching so as to use the first optical system when a signal is recorded and reproduced from the L0 layer and to use the second optical system when the signal is recorded and reproduced from the L1 layer, thereby the focus jump to the recording and reproducing objective layer of a disk medium having a plurality of layers is performed at high speed, so that layer-switching reproduction is continuously carried out. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
