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. 26, 1992
Filed:
Oct. 31, 1990
Evon C Greanias, Chevy Chase, MD (US);
Frank L Stein, Vienna, VA (US);
Robert Donaldson, Annapolis, MD (US);
Michael Gray, Annapolis, MD (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
An improved finger touch and stylus detection system for use on the surface of a display device is disclosed. An overlay having horizontal and vertical transparent conductors is coupled to the other elements of the system through a bus having a minimum number of bus wires. A control processor issues command signals which selectively couples the transparent conductors to a capacitive measuring device and a radiative measuring device to determine finger and stylus position respectively. The improvements to the system include a radiative stylus having a spherical antenna which receives the overlay signal independent of the angle at which it is held. Further, a contact detecting mode has been added to eliminate spurious stylus positions measured between strokes, when the stylus is proximate to but not in contact with the overlay.