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:
Aug. 08, 2000
Filed:
Feb. 13, 1998
Yasuji Ogawa, Otone-machi, JP;
Kabushikikaisha Wacom, , JP;
Abstract
An optical digitizer is constructed for determining a position of a pointing object projecting a light and being disposed on a coordinate plane. In the optical digitizer, a detector is disposed on a periphery of the coordinate plane and has a view field covering the coordinate plane for receiving the light projected from the pointing object and for converting the received light into an electric signal. A processor is provided for processing the electric signal fed from the detector to compute coordinates representing the position of the pointing object. A collimator is disposed to limit the view field of the detector below a predetermined height relative to the coordinate plane such that through the limited view field the detector can receive only a parallel component of the light which is projected from the pointing object substantially in parallel to the coordinate plane. A shield is disposed to enclose the periphery of the coordinate plane to block a noise light other than the projected light from entering into the limited view field of the detector.