| 摘要 |
<P>PROBLEM TO BE SOLVED: To precisely irradiate various kinds of optical information recording mediums having different protection base plate thickness with light beams. <P>SOLUTION: The BD coupling lens 18B and the HD coupling lens 18H are disposed respectively in the light paths WB, WH. The polarized direction of the light beam L1 is adjusted by using a liquid crystal element 15 according to the kinds of the optical disks 100. The light beam L1 is reflected or transmitted through by the polarization reflection film 16A and directed to the light path WB or WH. Thus, the light beam L1 with its radiation angle adjusted by the BD coupling lens 18B is converged on the optical disk 100B through the BD objective lens 8B, and the light beam L1 with its radiation angle adjusted by the HD coupling lens 18H is converged on the optical disk 100 through the HD objective lens 8H. <P>COPYRIGHT: (C)2009,JPO&INPIT |
