Invention Grant
- Patent Title: Noise cancellation technique for capacitive touchscreen controller using differential sensing
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Application No.: US13934496Application Date: 2013-07-03
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Publication No.: US09442610B2Publication Date: 2016-09-13
- Inventor: Ashutosh R. Joharapurkar , Jean C. Le , Natarajan Viswanathan , Patrick Chan
- Applicant: Maxim Integrated Products, Inc.
- Applicant Address: US CA San Diego
- Assignee: QUALCOMM Technologies, Inc.
- Current Assignee: QUALCOMM Technologies, Inc.
- Current Assignee Address: US CA San Diego
- Agency: Weaver Austin Villeneuve & Sampson LLP
- Main IPC: G06F3/045
- IPC: G06F3/045 ; G06F3/044 ; G06F3/041

Abstract:
A differential sensing scheme provides a means for detecting one or more touch events on a touch sensitive device in the presence of incident noise. Instead of sensing one touch sensitive channel, such as a row, column, or single touch sensor, multiple touch sensitive channels are sampled at a time. By sampling two nearby channels simultaneously and doing the measurement differentially, noise common to both channels is cancelled. The differential sensing scheme is implemented using simple switch-capacitor AFE circuitry. The originally sensed data on each individual channel is recovered free of common-mode noise. The recovered sensed data is used to determine the presence of one or more touch events and if present the location of each touch event on the touch sensitive device.
Public/Granted literature
- US20160209947A1 NOISE CANCELLATION TECNIQUE FOR CAPACITIVE TOUCHSCREEN CONTROLLER USING DIFFERENTIAL SENSING Public/Granted day:2016-07-21
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