Robust Touch Screen Readout System to Display Noise Using Multireference Differential Sensing Scheme for Flexible...

Area of Science:

• Electrical Engineering
• Materials Science
• Display Technology

Background:

• Flexible displays integrated with touch screen panels (TSPs) face significant display noise interference.
• This interference is an uncommon mode caused by the large panel load of the TSP in flexible displays.
• Existing methods struggle to effectively mitigate this severe noise, impacting touch performance.

Purpose of the Study:

• To propose and validate a new front-end architecture for TSP readout in flexible displays.
• To mitigate severe display noise interference and enhance touch sensitivity.
• To improve the signal-to-noise ratio (SNR) for reliable touch detection.

Main Methods:

• Implemented a differential sensing method with multi-reference TSP channels to minimize noise imbalance.
• Employed cascaded time-discrete bandpass sampling to boost touch sensitivity.
• Utilized a reconfigurable front-end block and programmable postfiltering for offset cancellation and sensitivity enhancement.

Main Results:

• Achieved a signal-to-noise ratio (SNR) of 50.5 dB at a 200 Hz scan rate.
• Attenuated aggravated display noise interference by over 6.84 dB compared to conventional methods.
• The designed chip occupied 4.8 mm² and consumed 17.6 mW from a 3 V supply.

Conclusions:

• The proposed front-end architecture effectively mitigates display noise interference in flexible TSPs.
• The design offers enhanced touch sensitivity and improved SNR, crucial for advanced display applications.
• The architecture is power-efficient and compact, suitable for integration into ultrathin flexible displays.