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. 27, 2014
Filed:
Apr. 26, 2011
Joseph Fisher, Jr., San Jose, CA (US);
Stephen Brian Lynch, Portola Valley, CA (US);
Robert Caston Curtis, San Jose, CA (US);
Joseph Fisher, Jr., San Jose, CA (US);
Stephen Brian Lynch, Portola Valley, CA (US);
Robert Caston Curtis, San Jose, CA (US);
Apple Inc., Cupertino, CA (US);
Abstract
Electronic devices may use buttons to gather user input. Button status monitoring circuits may be provided that apply a time-varying bias voltage to each button. The time-varying bias voltage may be held at a fixed non-zero level when the state of the button is being monitored and may be held at a level of zero volts when the state of the button is immaterial and is not being monitored. The reduction of the bias voltage across the button when the button is not being monitored prevents undesired acceleration in dendritic growth when the electronic device is exposed to moisture. The bias voltage may be pulsed by using a control circuit. The control circuit may generate a series of square wave pulses that are applied across the terminals.