Optics: measuring and testing – Range or remote distance finding – With photodetection
Patent
1997-05-05
1998-09-01
Hellner, Mark
Optics: measuring and testing
Range or remote distance finding
With photodetection
356445, G01C 308
Patent
active
058018174
ABSTRACT:
A method and apparatus for eliminating the effects of varying sample distance on optical measurements. In a first embodiment, a light source and a detector are both positioned in front of a measurement sample. A light source lens assembly focuses the light such that its focal point is behind the measurement sample, while a detector lens assembly focuses the light reflected from the measurement sample such that its focal point is in front of the measurement sample. Any movement of the measurement sample away from its nominal position does not affect the detector output because the effects of the source lens assembly and the detector lens assembly cancel each other. In a second embodiment, a light source and two detectors are positioned on one side off a measurement sample. The first detector is placed at a small angle relative to the sample normal, while the second detector is placed at a relatively large angle relative to the sample normal. A system output, which does not vary if the measurement sample is moved from its nominal position, comprises the weighted summation of the first and second detector outputs and a correction signal. The correction signal comprises a weighted difference of the first and second detector outputs.
REFERENCES:
patent: 3788741 (1974-01-01), Buechler
patent: 3815994 (1974-06-01), Peckham
patent: 4639140 (1987-01-01), Lerat
patent: 4647193 (1987-03-01), Rosenfeld
patent: 4716430 (1987-12-01), Stauffer
patent: 5028139 (1991-07-01), Kramer et al.
patent: 5049487 (1991-09-01), Phillips et al.
patent: 5159412 (1992-10-01), Willenborg et al.
patent: 5699164 (1997-12-01), Lehan et al.
Hellner Mark
UMM Electronics Inc.
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