发明名称 |
Optical head with objective lens having different numerical apertures to minimize light aberration with respect to optical disks of different thicknesses |
摘要 |
The objective lens of the present invention includes a center portion and a periphery portion surrounding the center portion. An aberration of the periphery portion is corrected such that a light spot is formed by the convergence of a luminous flux which has been transmitted through the periphery portion and then transmitted through a first light transmissive flat plate, and an aberration of the center portion is corrected such that a light spot is formed by the convergence of a luminous flux which has been transmitted through the center portion and then transmitted through a second light transmissive flat plate which is thicker than the first light transmissive flat plate.
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申请公布号 |
US6069860(A) |
申请公布日期 |
2000.05.30 |
申请号 |
US19970972913 |
申请日期 |
1997.11.18 |
申请人 |
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. |
发明人 |
MIZUNO, SADAO;KOMMA, YOSHIAKI |
分类号 |
G11B7/00;G11B7/135;(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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