专利检索 ap:("ILLINOIS TOOL WORKS") AND inv:"BRENIGAN III CHARLES F" 第 1 页

1.

发明公开
ACOUSTIC WAVE TOUCH DETECTION CIRCUIT AND METHOD 有权
标题翻译：面波，触摸检测电路和方法

公开(公告)号：EP1642260A4

公开(公告)日：2007-08-08

申请号：EP04754673

申请日：2004-06-02

申请人： ILLINOIS TOOL WORKS

发明人： KNOWLES TERENCE J , WEHRER WAYNE J , KALMUS CHRIS , BRENIGAN III CHARLES F

IPC分类号： G06F3/033 , H01H13/83 , H03K17/96

CPC分类号： G06F3/0436 , H01H13/83 , H01H2239/054 , H03K17/96 , H03K2217/96011

摘要： A circuit for an acoustic wave switch or sensor (10) having a resonant acoustic wave cavity detects a touch or sensed event using a time domain approach. The circuit includes a controller that drives an acoustic wave transducer (12, 12’) to generate a resonant acoustic wave in the acoustic wave cavity (14, 14’) during a first portion of a sampling cycle. In a second portion of the sampling cycle, the controller (30) monitors the time that it takes for the acoustic wave signal from the transducer to decay to a predetermined level, based on the decay time, the controller detects a sensed event, such as a touch on the acoustic wave switch/sensor.