发明名称 |
Device for scanning a radiation-reflecting information surface with optical radiation. |
摘要 |
<p>An optical scanning device is described which comprises a radiation source (6), an objective system (8) and a diffraction grating (9) which is arranged between the objective system and the radiation source to separate the radiation beam (b') reflected by the information surface (2) to be scanned from the beam (b) emitted by the radiation source and for introducing astigmatism in the reflected beam (b') for the purpose of focus-error detection. In principle, the grating (9) has a constant grating period and is arranged at a small angle ( alpha ) in the beam (b').</p> |
申请公布号 |
EP0255173(A1) |
申请公布日期 |
1988.02.03 |
申请号 |
EP19870201391 |
申请日期 |
1987.07.21 |
申请人 |
KONINKLIJKE PHILIPS ELECTRONICS N.V. |
发明人 |
GREVE, PETER FERDINAND |
分类号 |
G02B7/28;G11B7/09;G11B7/135;(IPC1-7):G11B7/09 |
主分类号 |
G02B7/28 |
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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