发明名称 |
System for detecting height fluctuations of a surface on a recording medium in an optical recording or reproducing apparatus |
摘要 |
The invention relates to a system for detecting the height fluctuations of a surface on a recording medium in an optical recording or reproducing apparatus. A light source emits a main light beam for recording or reproducing. An optical system, including an objective lens, focuses the main light beam into a spot on the surface. A first reflecting mirror introduces a sublight beam into the peripheral part of the main light beam. The sub-light beam advances in a forward path through the objective lens to be projected onto the recording surface and reflected thereby. The sub-beam returns again through the objective lens along the peripheral part of the main light beam, but on the opposite side from said forward path. A second reflecting mirror extracts the sub-light beam in the return path out of the light to operate a detector which detects fluctuations in the distance between the objective lens and the recording surface and to produce control signals maintaining a constant distance between the objective lens and recording surface.
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申请公布号 |
US4110607(A) |
申请公布日期 |
1978.08.29 |
申请号 |
US19760753005 |
申请日期 |
1976.12.21 |
申请人 |
VICTOR COMPANY OF JAPAN, LTD. |
发明人 |
HONJO, YOSHIHIKO;KURODA, JUNJI |
分类号 |
G01B11/02;G01B11/30;G11B7/09;(IPC1-7):G01J1/20 |
主分类号 |
G01B11/02 |
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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