发明名称 |
Optical head apparatus, optical information recording and reproducing apparatus, method for detecting aberration and method for adjusting optical head apparatus |
摘要 |
An optical head apparatus capable of stably obtaining a detection signal of spherical aberration even with a high density optical disk. A spherical aberration error signal is obtained by: dividing the returning light from the optical disk into a transmitted light and a diffracted light; reproducing information with the transmitted light having a larger amount of light while dividing the diffracted light having a small amount of light into two regions, i.e., region near the optical axis and a region distant from the optical axis; determining amounts of focus deviation in respective regions as focus error signals; and taking the difference signal therebetween. Thus, it is possible to detect the amount of spherical aberration with the SN ratio of the information reproducing signal kept at high level.
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申请公布号 |
US6967916(B2) |
申请公布日期 |
2005.11.22 |
申请号 |
US20010975396 |
申请日期 |
2001.10.10 |
申请人 |
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. |
发明人 |
SANO KOUSEI;KADOWAKI SHIN-ICHI;KOMMA YOSHIAKI;NISHINO SEIJI;YASUDA KATSUHIKO;YASUDA AKIHIRO |
分类号 |
G11B7/09;G11B7/13;G11B7/135;(IPC1-7):G11B7/00 |
主分类号 |
G11B7/09 |
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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