发明名称 |
Objective lens for optical head |
摘要 |
A single element objective lens for an optical disc drive converges a laser beam, which is emitted by a laser source, on a data recording surface of an optical disc through a protective layer of the optical disc. One surface of the objective lens is divided into a central area including an optical axis thereof and a peripheral area surrounding the central area. The peripheral area is provided with a diffraction lens structure formed by a plurality of concentric annular zones including minute steps. The central area is a continuous surface having no stepped portions. The diffraction lens structure compensates for variation of converging characteristic of the objective lens due to a change of a temperature.
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申请公布号 |
US6741402(B2) |
申请公布日期 |
2004.05.25 |
申请号 |
US20010973114 |
申请日期 |
2001.10.10 |
申请人 |
PENTAX CORPORATION |
发明人 |
TAKEUCHI SHUICHI;MARUYAMA KOICHI |
分类号 |
G02B13/00;G02B7/02;G02B13/18;G02B27/00;G11B7/00;G11B7/125;G11B7/135;(IPC1-7):G02B3/08;G02B5/18;G02B27/44 |
主分类号 |
G02B13/00 |
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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