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:
Nov. 19, 2002
Filed:
Mar. 30, 2001
Tuyoshi Ishikawa, Tokyo, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A pattern reading apparatus reads a pattern from a reflective object. The pattern reading apparatus includes a minute-area light source, an objective lens system, an imaging lens, and an imaging element. The objective lens system causes the illumination light beam from the light source to be incident on the object and converges the light beam reflected from the object. The imaging lens forms an image of the object using only a diffused component of light which has been reflected from the object. A spatial filter has a shading region that shades a portion of the reflected light beam from the object surface which has passed through the spatial filter and forms the image of the light source. The imaging element reads the image of the pattern formed by the light beam having passed through the spatial filter. An extension of a principal plane of the imaging lens interposed between the object surface and an imaging surface, an extension of a plane of the imaging surface and an extension of a plane of the object surface, intersect at a point.