Touch Sensor Multiplexing for Display Panel Wiring Reduction
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Solution Overview
Problem
As display panels enlarge, the number of touch sensors increases, leading to a corresponding increase in the number of integrated circuits and touch lines, which complicates the wiring and reduces efficiency in touch sensing technology.
Innovation Solution
A display device with a selecting circuit that connects internal lines to external lines using switches, allowing for reduced wiring and integrated circuits by employing a self-capacitance method to drive touch sensors, and an auxiliary signal circuit to minimize noise from parasitic capacitances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the number of touch sensors is increased to support larger display panels, then the coverage area is improved, but the number of integrated circuits and external lines increases
Solution Approach 1:
The patent segments the touch sensor array into multiple groups that share common external lines through the selecting circuit. Instead of dedicating separate external lines to each touch sensor, the sensors are divided into groups that can be selectively connected to external lines via switches, reducing the total number of external lines required.
Solution Approach 2:
The patent introduces a time dimension by implementing sequential scanning of touch sensors through the selecting circuit. Multiple touch sensors share the same external lines by being activated at different time intervals, transforming a spatial problem (number of lines) into a temporal solution (sequential access).
2Area of stationary object
If the number of touch sensors is increased to support larger display panels, then the coverage area is improved, but the wiring complexity increases
Solution Approach 1:
The patent merges multiple internal lines into fewer external lines through the selecting circuit. The switching network combines multiple sensor line connections into a reduced set of external lines, significantly simplifying the wiring between the touch panel and the driving integrated circuit.
Solution Approach 2:
The selecting circuit acts as an intermediary between the numerous internal touch sensor lines and the limited external lines. This intermediate switching layer enables efficient signal routing with minimal external connections, reducing wiring complexity while maintaining full sensor access.
3Reliability
If touch sensors are driven using traditional methods, then the touch sensing function is achieved, but noise from parasitic capacitances reduces sensing sensitivity
Solution Approach 1:
The patent extracts and separates the sensing function from the driving function. The sensing circuit and driving circuit operate independently with separate signal paths, allowing the sensing operation to be performed without interference from driving signals, thereby eliminating noise from parasitic capacitances while maintaining touch sensing reliability.
Data Source
AI summary
The present disclosure relates to a technology of sensing a touch. According to the present disclosure, touch sensors are driven in a time division way using multiplexers disposed on a panel and auxiliary signals, with a same phase as that of driving signals, are supplied to electrodes around a touch sensor in driving so as to reduce the introduction of noises from the neighboring electrodes.