发明名称 |
Apparat til læsning af en registreringsbærer med optisk informationsstruktur. |
摘要 |
<p>In an apparatus for reading a record carrier on which information is stored in an optically readable structure, the radiation which is supplied by the radiation source is split into a read beam and an auxiliary beam for determining the focussing of the read beam on the record carrier. Said auxiliary beam is intercepted by two radiation-sensitive detectors. By disposing a radiation-absorbing knife between the radiation source and the Wollaston prism a part of the auxiliary beam is blocked. Thus, an accurate indication can be obtained of the magnitude and the direction of a focussing error.</p> |
申请公布号 |
DK140616(B) |
申请公布日期 |
1979.10.08 |
申请号 |
DK19750005047 |
申请日期 |
1975.11.10 |
申请人 |
N.V. PHILIPS' GLOEILAMPENFABRIEKEN |
发明人 |
LIEUWE BOONSTRA;ANTONIUS ADRIANUS MARIUS VAN ALEM |
分类号 |
G02B7/28;G02B27/40;G11B7/09;G11B7/1356;G11B7/1359;G11B7/1381;(IPC1-7):G11B7/08 |
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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