发明名称 |
Apparatus for monitoring optical path differences utilizing an etalon |
摘要 |
The optical path difference between two reflecting surfaces of an etalon 2 is monitored by directing a light beam B onto the etalon, directing the reflected beam Ba from the etalon onto an optical reference wedge 3 and directing the reflected beam Bb from the wedge onto a linear photo-detector array 4. The position along the array 4 of a peak of light intensity represent the location of an interference maximum and corresponds to reflection of light at that position along the length L of the wedge 3 at which the optical path difference of the wedge equals the optical path difference of the etalon being measured. The etalon 2 may comprise a data carrier encoded by variations in its relief (and therefore in its optical path difference), which data carrier may comprise a rotatable disc and the apparatus may comprise an optical head movable radially of the disc to read different concentric tracks. |
申请公布号 |
US4768182(A) |
申请公布日期 |
1988.08.30 |
申请号 |
US19860927118 |
申请日期 |
1986.11.05 |
申请人 |
IMPERIAL CHEMICAL INDUSTRIES PLC |
发明人 |
HATFIELD, JAMES H. |
分类号 |
G01B11/06;G01B11/14;G01M11/00;G06K7/14;G11B7/005;G11B7/24;(IPC1-7):G11B7/00 |
主分类号 |
G01B11/06 |
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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