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:
Sep. 03, 1991
Filed:
Apr. 16, 1990
David I Dunthorn, Anderson County, TN (US);
Elographics, Inc., Oak Ridge, TN (US);
Abstract
A resistor electrode type of gradient sheet for a touch sensor having reduced ripple and bow of equipotential lines along edges and in the corners of the sensor. Orthogonal electrical fields are produced on a resistive surface so as to give coordinates of a selected position. T-shaped electrodes of a selected effective length and spacing are attached to the resistive surface, the length and spacing selected to substantially eliminate the bow of the equipotential fields. Each electrode is connected to a selected connection point along a resistor chain positioned along each edge of the resistive surface to provide selected voltages to the surface. Preferably, each resistance chain is made up of at least one resistance unit between each electrode connection point, with each unit formed of a pair of spaced-apart conductive lines applied to the resistive surface. In addition, the gradient sheet has corner electrodes that are connected to corner junctions of the resistor chains, preferably through a resistor of a selected value. This results in a sensor having an increased linear work area as compared with the prior art.