OFDM and TDM based sensing method for large projected mutual-capacitance touch screens

2016 ◽  
Author(s):  
M. G. A. Mohamed ◽  
A. N. Ragheb ◽  
Hossam Hassan ◽  
HyungWon Kim
Keyword(s):  
Mutual Capacitance ◽  
Touch Screens

scholarly journals Numerical Simulation of Mutual Capacitance Touch Screens for Ungrounded Objects

2017 ◽  
Vol 17 (16) ◽  
pp. 5143-5152 ◽  
Author(s):  
Christian Bjorge Thoresen ◽  
Ulrik Hanke
Keyword(s):  
Numerical Simulation ◽  
Mutual Capacitance ◽  
Touch Screens

scholarly journals Concurrent Driving Method with Fast Scan Rate for Large Mutual Capacitance Touch Screens

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed Gamal Ahmed Mohamed ◽  
HyungWon Kim
Keyword(s):  
Conventional Method ◽  
Ambient Noise ◽  
Touch Screen ◽  
Experimental Results ◽  
Control Technique ◽  
Scan Rate ◽  
Mutual Capacitance ◽  
Rate Improvement ◽  
Snr Improvement ◽  
Touch Screens

A novel touch screen control technique is introduced, which scans each frame in two steps of concurrent multichannel driving and differential sensing. The proposed technique substantially increases the scan rate and reduces the ambient noise effectively. It is also extended to a multichip architecture to support excessively large touch screens with great scan rate improvement. The proposed method has been implemented using 0.18 μm CMOS TowerJazz process and tested with FPGA and AFE board connecting a 23-inch touch screen. Experimental results show a scan rate improvement of up to 23.8 times and an SNR improvement of 24.6 dB over the conventional method.

scholarly journals Modeling of Ungrounded Tangibles on Mutual Capacitance Touch Screens

2020 ◽  
Vol 20 (1) ◽  
pp. 269-276
Author(s):  
Christian Bjorge Thoresen ◽  
Ulrik Hanke
Keyword(s):  
Mutual Capacitance ◽  
Touch Screens

scholarly journals A Mutual Capacitance Touch Readout IC with Synchronization in Touch and Mobile Display Driving for High Refresh Rate AMOLED Panels

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 922
Author(s):  
Seunghoon Ko
Keyword(s):  
System Architecture ◽  
Noise Suppression ◽  
Touch Screen ◽  
Horizontal Line ◽  
Time Sharing ◽  
Refresh Rate ◽  
Front End ◽  
Scan Rate ◽  
Mutual Capacitance ◽  
Analog Voltage

This paper presents a mutual capacitance touch readout IC architecture for 120 Hz high-refresh-rate AMOLED displays. In high-refresh-rate AMOLED panels, whole pixels in a horizontal line should be updated without any time-sharing with each other, leading to an amplified display noise on touch screen panel (TSP) electrodes. The proposed system architecture mitigates severe display noise by synchronizing the driving for the TSP and AMOLED pixel circuits. The proposed differential sensing technique, which is based on noise suppression in reference to mutual capacitance channels, minimizes common-mode display noise. In the front-end circuit, intrinsic circuit offset is cancelled by a chopping scheme, which correlates to the phase of the driving signals in the TSP driver and operating clocks of the front-end. Operating at a 120 Hz scan-rate, it reduces display noise by more than 11.6 dB when compared with the conventional single-ended TSP sensing method. With a built-in 130-nm CMOS, a prototype IC occupies an area of 8.02 mm2 while consuming 6.4-mW power from a 3.3 V analog voltage supply.

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