Radiant energy – Photocells; circuits and apparatus – Photocell controlled circuit
Patent
1995-06-06
1996-06-25
Sikes, William L.
Radiant energy
Photocells; circuits and apparatus
Photocell controlled circuit
250548, 356349, 356354, G06K 7015, G01B 902
Patent
active
055302564
ABSTRACT:
A position detecting apparatus comprises a double-beam producing device for producing two beams different in frequency from each other, which are guided to irradiate a diffraction grating on an object to be inspected in two predetermined directions, and a detector photoelectrically detecting through an objective optical system diffracted light produced by the diffraction grating, in which the double-beam producing device comprises a light source for supplying a beam of a single wavelength or multiple wavelengths, a beam splitting device for splitting the beam from the light source into two predetermined beams, a relay optical system for converging the two split beams at a predetermined position, and a frequency difference producing device disposed at or near a converging position by the relay optical system, for producing a predetermined frequency difference between the two split beams.
REFERENCES:
patent: 5070250 (1991-12-01), Komatsu
patent: 5109376 (1992-04-01), Ikeya
patent: 5184196 (1993-02-01), Nakagawa
patent: 5347356 (1994-09-01), Ota
patent: 5394240 (1995-02-01), Matsumoto
patent: 5450199 (1995-09-01), Rieder
patent: 5481360 (1996-01-01), Fujita
Mizutani Hideo
Ota Kazuya
Nguyen Tiep H.
Nikon Corporation
Sikes William L.
LandOfFree
Double-beam light source apparatus, position detecting apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Double-beam light source apparatus, position detecting apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Double-beam light source apparatus, position detecting apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2190876