发明名称 |
Flat-plate lens |
摘要 |
The invention discloses a flat-plate lens to be built in an optical recording medium for improving the image-forming characteristics of the recording medium. The flat-plate lens of the invention comprises a layered thin film having a periodical structure in the direction of thickness thereof corresponding to a wavelength slightly longer than the wavelength of the light used for recording and retrieving information into and from the recording medium. The thin film of a periodical structure is formed by alternate lamination of pluralities of layers two materials having different refractive indices such as a combination of MgF<SUB>2 </SUB>and ZnS. When the thin film having such a periodical structure is formed with good uniformity allover the surface, the image-forming performance on the recording layer can be uniform irrespective of the position on the flat-plate lens.
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申请公布号 |
US7099264(B2) |
申请公布日期 |
2006.08.29 |
申请号 |
US20030442213 |
申请日期 |
2003.05.21 |
申请人 |
NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCEAND TECHNOLOGY |
发明人 |
FUKAYA TOSHIO;TOMINAGA JUNJI |
分类号 |
G02B5/18;G11B7/00;G02B3/00;G02B5/32;G11B7/135;G11B7/24;G11B7/257;G11B7/26 |
主分类号 |
G02B5/18 |
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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