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:
Oct. 06, 1992
Filed:
Jun. 08, 1990
David W Caldwell, Holland, MI (US);
Nicholas W Medendorp, Holland, MI (US);
Donnelly Corporation, Holland, MI (US);
Abstract
A touch responsive user selection system including a plurality of touch pads on an insulated substrate and a logic circuit for responding to the change of impedance of any of the pads for setting or resetting a latch and thereby producing an output signal indicative of a user selection. A coincidence detector responds to the simultaneous change of impedance of two or more different touch pads by inhibiting the logic circuit from producing an output signal both during the coincidence and for a predetermined period of time after the coincidence has ceased. The logic circuit is made up of components that are arranged in a fashion that causes the circuit to respond to a ratio of signals that vary in proportion to supply voltage. In this manner, a touch-responsive system is provided that may be used with an unregulated power supply while functioning with extreme variations in supply voltage.