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. 18, 1987
Filed:
Mar. 11, 1985
John E Talmage, Jr, Oak Ridge, TN (US);
William A Gibson, Knoxville, TN (US);
Elographics, Inc., Oak Ridge, TN (US);
Abstract
An electrographic touch sensor having Z-axis capability. In one embodiment, a uniform resistive coating is applied to one surface of a substrate and it is within this coating that orthogonal electrical fields are produced using suitable electrodes and voltage applications to give coordinates of a selected position. Overlying the resistive coating is a flexible pickoff sheet having a conductive layer facing the combination. Interposed between the resistive coating and the conductive layer is an array of a material having a substantially greater resistivity than that of the resistive coating. Signals corresponding to the X- and Y-coordinates of a touched point on the sensor are obtained in a substantially conventional manner using an amplifier and an analog to digital converter. If desired, a Z-axis component signal due to pressure/force can be obtained in a separate part of the measuring cycle. This Z-axis signal is inversely related to a change in the effective contact resistance between the resistive coating and the pick-off sheet caused by the pressure/force. The change in this contact resistance is 'enhanced' by the high resistance material such that different values of pressure/force can be determined. Numerous other embodiments are described including two resistive sheet sensors and enhancing materials that are considered to be insulators.