Display Touch Panel Parallel Self-Capacitance Detection
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Solution Overview
Problem
Existing display devices with built-in touch panels face challenges in increasing panel definition and driving speed due to the alternation of display and touch sensing modes, which can lead to false touch detection by water droplets and affect the display quality.
Innovation Solution
A display device configuration with a self-capacitance and mutual-capacitance type touch panel that allows parallel operation of touch detection and display by using a gate signal to overlap with drive electrodes, while applying self-capacitance detection signals to non-overlapping detection electrodes, preventing interference and enabling faster driving and higher definition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If display mode and touch sensing mode are alternately executed within one frame period, then effects of touch detection on display and effects of display on touch detection are prevented, but the period of each mode is shortened, making it difficult to increase panel definition and driving speed
Solution Approach 1:
The patent applies periodic action by dividing the frame period into multiple sub-periods, where touch sensing operations are performed periodically at specific timings (e.g., during horizontal blanking periods or specific vertical blanking periods) rather than alternating entire display and touch modes. This allows touch sensing to occur at regular intervals without interrupting the continuous display refresh, thereby maintaining touch detection accuracy while enabling higher driving speeds and panel definition.
2Measurement precision
If self-capacitance type touch detection is implemented in a mutual-capacitance type touch panel to identify false detection caused by water droplets, then false detection is prevented, but voltage applied to touch sensor array may affect pixel array and vice versa
Solution Approach 1:
The patent applies local quality by performing self-capacitance measurements on specific local regions (e.g., detection electrodes in non-display areas or specific sensor regions) rather than uniformly across the entire touch panel. This localized approach allows water droplet detection to occur in regions that do not interfere with pixel operation, preventing false detection while avoiding voltage interference with the display quality.
Solution Approach 2:
The patent uses detection electrodes as intermediaries between the touch sensor array and the pixel array. These detection electrodes are specifically configured to sense touch events and water droplets without directly interfering with pixel operation. The detection electrodes act as a buffer zone, allowing self-capacitance measurements to be performed while isolating the pixel array from voltage fluctuations, thereby maintaining both touch detection accuracy and display quality.
3Manufacturing precision
If the number of pixel arrays is increased to make display panel higher in definition, then display quality is improved, but the period of display mode in one pixel array is further shortened
Solution Approach 1:
The patent applies continuity of useful action by enabling the display mode to operate continuously without interruption from touch sensing operations. By performing touch sensing during horizontal blanking periods or specific vertical blanking periods rather than alternating entire display and touch modes, the display refresh can proceed continuously at high speed. This continuous operation allows the display panel to achieve higher definition with more pixel arrays while maintaining adequate display mode period for each pixel.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration allows for simultaneous touch detection and display without interference, enabling increased driving speed and panel definition by separating the effects of touch detection and display signals, thus preventing false detections and improving overall performance.
Implementation Method 1
a plurality of detection electrodes disposed alternately with the plurality of drive electrodes in the second direction and forming an electrostatic capacitance with the plurality of drive electrodes
Implementation Method 2
a gate drive controller configured to sequentially supply a gate signal to the plurality of gate lines
Implementation Method 3
a self-capacitance acquisition unit configured to supply a drive signal for self-capacitance detection to the plurality of detection electrodes and acquire a self-capacitance detection signal from the plurality of detection electrodes
Data Source
AI summary
A display device includes a plurality of drive electrodes, a plurality of detection electrodes, and a touch detection driver configured to supply a drive signal for self-capacitance detection to the plurality of detection electrodes and acquire a self-capacitance detection signal from the plurality of detection electrodes. The touch detection driver is configured to supply the drive signal for self-capacitance detection to at least one of the plurality of detection electrodes while the gate signal is being supplied to gate lines overlapping any one of the plurality of drive electrodes.