发明名称 |
Optical Disc recording/reproducing apparatus recording/reproducing information to/from optical discs according to different standards |
摘要 |
An optical disc reproducing apparatus includes a semiconductor laser, an objective lens converging a laser beam from the semiconductor laser on a recording surface of an optical disc, a polarization plane rotating unit selectively rotating the plane of polarization of the laser beam according to the thickness of a substrate of the optical disc, and a polarizing filter selectively shading a peripheral portion of the laser beam having the rotated plane of polarization. In one embodiment, a numerical aperture changing unit includes a non-patterned twisted nematic liquid crystal, and the polarizing filter includes a polarizing film having a polarization characteristics at its peripheral portion.
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申请公布号 |
US6167019(A) |
申请公布日期 |
2000.12.26 |
申请号 |
US19990474554 |
申请日期 |
1999.12.29 |
申请人 |
SANYO ELECTRIC CO., LTD. |
发明人 |
TSUCHIYA, YOICHI;KAJIYAMA, SEIJI;KANOU, YASUYUKI;ICHIURA, SHUICHI |
分类号 |
G11B7/00;G11B7/013;G11B7/135;G11B19/12;(IPC1-7):G11B7/00 |
主分类号 |
G11B7/00 |
代理机构 |
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代理人 |
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主权项 |
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