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. 31, 2010
Filed:
Jul. 29, 2008
Dodge Daverman, Chicago, IL (US);
David Cranfill, Antioch, IL (US);
Michael Olley, Lake Zurich, IL (US);
Dodge Daverman, Chicago, IL (US);
David Cranfill, Antioch, IL (US);
Michael Olley, Lake Zurich, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A capacitive force sensor () includes a substrate () having at least one electrode pair () defining a capacitance disposed thereon. The substrate () is fixed relative to a first plate (). A drive circuit () is configured to apply a voltage relative to a circuit ground () to the electrode pair (). The first plate () is separated from a second plate () that is coupled to circuit ground () by a compliance member (). The compliance member () is configured to oppose a compression force () while allowing the first plate () to physically move relative to the second plate (). A capacitive detection circuit () is then configured to detect a change the capacitance when the compliance member () is compressed. The compression force () is then determined from the change in capacitance and the spring constant of the compliance member ().