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. 22, 2012
Filed:
Nov. 26, 2008
Craig A. Cordeiro, Westford, MA (US);
Bernard O. Geaghan, Salem, NH (US);
Craig A. Cordeiro, Westford, MA (US);
Bernard O. Geaghan, Salem, NH (US);
3M Innovative Properties Company, Saint Paul, MN (US);
Abstract
Systems and methods determine the position of a touch on a surface of a device, such as a touch-sensitive device, by using passively-induced position-dependent electrical charges. In such a method, the position of a touching implement is determined on the sensing surface of a device. The method includes charging the sensing surface during a first time period by connecting all four corners of the sensing surface to a reference voltage, and over a second time period discharging two adjacent corners of the sensing surface into an integrator capacitor while connecting the two opposite corners to ground. The first and second time periods together form a charge/discharge cycle that is repeated a plurality of times, after which an output of the integrator capacitor is measured. This sequence is performed for each of the four pairs of adjacent corners of the sensing surface, resulting in four integrator capacitor output measurements, each of the four measurements being associated with a different sensing surface edge. The position of the touching implement on the sensing surface is then calculated using the four charge measurements.