发明名称 |
DEVICE FOR SEPARATING AN OPTICAL SIGNAL FROM THE AMBIENT LIGHT |
摘要 |
<p>An arrangement for separating disturbing ambient light from an optical data signal, comprising an interference filter (1), the passband of which matches the wavelength of the optical data signal, and further comprising two photodiodes which are so arranged that one photodiode receives the light (IS, IAT) transmitted through the interference filter, and that the other receives the reflected light (IAR). Adjusting means, e.g., in the form of a settable aperture (4) or an additional simple filter (5) are provided for adjusting the transmitted and reflected portions of the ambient light to each other. Output signal (S1, S2) of both photodiodes are subtracted from each other in compensation circuitry (6). This results in compensation of the ambient light components so that at the output a signal (SR) is available which depends only on the actual data signal (IS).</p> |
申请公布号 |
EP0012818(B1) |
申请公布日期 |
1984.05.30 |
申请号 |
EP19790104342 |
申请日期 |
1979.11.06 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
BAPST, URS HEINRICH;GFELLER, FRITZ;VETTIGER, PETER |
分类号 |
G01J1/42;G01J1/44;G02F2/00;G02F2/02;G06K7/10;H04B10/114;(IPC1-7):06K7/10;06F3/033;04B9/00;06K7/14 |
主分类号 |
G01J1/42 |
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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