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:
Jul. 02, 1996
Filed:
Dec. 17, 1993
Joel C Johnson, Lake Oswego, OR (US);
Robert B Hill, Portland, OR (US);
EDI of Louisiana, Inc., Baton Rouge, LA (US);
Abstract
An optical scanner (100) includes a rotating scanner disk (116) that integrates a multifocal Fresnel fixation lens (114), a Fresnel optical scanner (122, 124), and an angular position encoder (140) into a unitary, inherently aligned, compression-molded component. An individual being identified views through the multifocal Fresnel fixation lens an image of a pinhole (108) illuminated by a light source (104). The multifocal lens is centered on the disk and creates multiple in- and out-of-focus images (180, 182, 184, 186) of the pinhole image. The combined image appears to the individual as a set of circular images (190, 192, 194, 196), one of which is in focus. The images appear concentric when the individual is properly aligned with the disk and associated optics. The Fresnel optical scanner receives IR light from the light source and creates an IR scanning beam (126) when the disk is rotated. IR light reflected by the fundus (12) of the individual returns via a reciprocal path, by way of a beam splitter (112), and into a detector (134) to generate image data. The disk integrates and inherently aligns multiple optical elements, resulting in a 60 percent reduction of optical components relative to prior scanners.