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:
Feb. 07, 1989
Filed:
Sep. 30, 1987
Yoichi Sato, Tokyo, JP;
Kazuo Ichinokawa, Tokyo, JP;
NEC Corporation, , JP;
Abstract
A novel digitizer operable on an optical digitization basis comprises a transparent flat plate as a light active surface located on a graphic data recording medium, and a cursor functioning as an optical recognition device movable on the transparent flat plate. A predetermined coordinate correlative pattern is described on or in the transparent flat plate with a fluorescent paint. The cursor comprises a positioning arm provided on the outer periphery thereof to visually trace a data location on the recording medium in accordance with a movement of the cursor to effect positioning of the cursor with respect to the data location, an optical system including a light source, an optical filter assembly, and a light focusing lens etc., and a CCD sensor unit to sense light emitted from a partial pattern which falls within a predetermined limited visual range of the pattern. By irradiation of the pattern, fluorescent light is emitted therefrom. The optical digitizer is operative to determine position coordinates of a graphic data on the recording medium in accordance with an projected image of fluorescent light sensed by the sensor unit. Thus, such an implementation makes it possible to realize a small-sized, high accuracy digitizer completely free from influence of electromagnetic wave noise.