发明名称 |
Optical disc readout apparatus for different types of optical discs |
摘要 |
An optical disc readout apparatus having an optical system which guides a laser beam onto a signal recording surface of a loaded disc through an objective lens and guides a reflected laser beam onto a photo detector. An effective numerical aperture of the objective lens is adjusted according to the thickness between a substrate surface of the loaded disc and the signal recording surface, and the laser spot with a diameter suitable to a recording density of the loaded disc is focused on the signal recording surface. Therefore, the data recorded in a plurality of optical discs with different thickness or recording densities can be read out.
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申请公布号 |
US5856965(A) |
申请公布日期 |
1999.01.05 |
申请号 |
US19960646063 |
申请日期 |
1996.05.07 |
申请人 |
SANYO ELECTRIC CO., LTD. |
发明人 |
TSUCHIYA, YOICHI;KAJIYAMA, SEIJI;KANOU, YASUYUKI |
分类号 |
G11B7/00;G11B7/0037;G11B7/005;G11B7/09;G11B7/125;G11B7/135;G11B20/10;(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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地址 |
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