The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 16, 1990
Filed:
Oct. 24, 1988
Gary E Sommargren, Santa Cruz, CA (US);
Zygo Corporation, Middlefield, CT (US);
Abstract
A system for generating a spatially stable, small diameter light beam (18) which serves as a straight reference line over long distances may use the direction of propagation of light and one fixed point (11, 12) or may be between two fixed points (12, 21). In either instance, a light source (1) emits a beam (2) which is expanded, collimated and spatially filtered (3, 4). In the first instance, the collimated light wave (11) produced is diffracted by a sphere (12) to produce the small diameter light beam (18) which is constituted by a continuum of spots (16) which, in turn, produces a Poisson's spot (16) on a detector (21) which spatially samples the intensity of the spot (16). The resultant voltage (22) from each active detection are sent to a center locating electronics/computer (24) which processes the voltages (22) to give the position of the detector (21) relative to the straight reference line (18). In the second instance, the collimated light wave (11) is produced by reflecting the beam (5) passing through the pinhole (4) from a steering mirror (6) which can be tilted about two axes by applying error signal voltages (27, 28) to tilt adjusters (7, 8) which are related to the displacement of spot (16) from the center of detector (21) in the X and Y directions. The tilting of the mirror (6) changes the angle of incidence of the light wave (11) on the sphere (12) so that the spot (16) is centered on the detector (21).