Invention Grant
- Patent Title: Capacitive touch sensing and light emitting diode drive matrix
- Patent Title (中): 电容触摸感应和发光二极管驱动矩阵
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Application No.: US12642089Application Date: 2009-12-18
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Publication No.: US08427450B2Publication Date: 2013-04-23
- Inventor: Chien-Yi Lin
- Applicant: Chien-Yi Lin
- Applicant Address: US AZ Chandler
- Assignee: Microchip Technology Incorporated
- Current Assignee: Microchip Technology Incorporated
- Current Assignee Address: US AZ Chandler
- Agency: King & Spalding L.L.P.
- Main IPC: G06F3/045
- IPC: G06F3/045

Abstract:
A pulse is applied through a capacitive touch key sensor to a sampling capacitor of an analog-to-digital converter (ADC). The voltage charge arriving at the sampling capacitor will be maximum when there is substantially no shunt capacitance between the capacitive touch key sensor and the sampling capacitor. However, a object such as an operator's finger when in close proximity to the capacitive touch key sensor will create a shunt to ground capacitance that diverts some of the charge that is supposed to go to the sampling capacitor and thereby reducing the voltage charge on the sampling capacitor. This change in charge voltage when the capacitive touch key sensor is activated (touched) may be easily detected with the ADC. In addition, light emitting diode (LED) displays may be integrated with the capacitive touch key sensors and use the same connections on an integrated circuit device in a time division multiplexed manor.
Public/Granted literature
- US20100177058A1 CAPACITIVE TOUCH SENSING AND LIGHT EMITTING DIODE DRIVE MATRIX Public/Granted day:2010-07-15
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