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:
May. 24, 1983
Filed:
Nov. 25, 1980
Paul A Johnson, Santa Barbara, CA (US);
BEI Electronics, Inc., Little Rock, AK (US);
Abstract
An optical system for an optical encoder of the type having an optical code disc with a plurality of code tracks, and a multichannel photodetector for receiving modulated light from the code tracks, the optical system comprising a light source for producing a line of light, an optional collimating lens for receiving divergent rays of light from said light source and for directing the light in generally parallel rays toward the code disc, an objective lens disposed between the collimating lens and the code disc for focussing the light in a sharp line on the code disc, a housing for supporting the collimating lens and having a seat for receiving the objective lens, an aperture plate having an aperture slit therein aligned with the objective lens, and means for holding the aperture plate on the housing with the objective lens retained between the seat and the plate. Flanges may be provided on the housing to retain the aperture plate, preferably in a flexed position in engagement with the objective lens, which may be cylindrical, semicylindrical, or in the form of a doublet or a triplet. A grating may be substituted for the plate and the objective lens. In an alternative construction, the aperture plate may be molded into a cylindrical objective lens.