Touch Panel Display Signal Timing Control
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Solution Overview
Problem
Existing touch panel-equipped display devices face challenges in suppressing the influence of drive signal supply on the display screen during touch position detection, as the signal input for touch detection interferes with the display control period, affecting the display quality.
Innovation Solution
The display control unit supplies data signals to pixel electrodes sequentially, while the touch position detection control unit starts the drive signal supply to the drive electrode during the scan write period, avoiding the data write period of the color with the highest luminosity, thereby minimizing interference with the display.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If touch position detection is performed in the display control period, then touch position detection can be performed, but the supply of drive signal causes influence on the display screen
Solution Approach 1:
The patent segments the display control period into multiple sub-periods corresponding to different colors (R, G, B), and further segments the touch detection timing to occur during specific sub-periods (R and B periods) while avoiding others (G period). This temporal segmentation allows touch detection to proceed without interfering with the most luminous color display, thus resolving the contradiction between performing touch detection and avoiding display interference.
2Ease of operation
If drive signal is supplied to drive electrode during scan write period, then touch position detection is enabled, but display quality may be degraded
Solution Approach 1:
The patent applies local quality by making the drive signal supply timing color-specific. The drive signal is supplied during the scan write period but selectively avoided during the green color's data write period, while being permitted during red and blue periods. This localized timing adjustment maintains display quality for the most sensitive color (green) while enabling touch detection functionality, thus resolving the contradiction between ease of operation and reliability.
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 approach effectively reduces the impact of drive signal supply on the display screen, particularly by limiting the influence to the color with the lowest luminosity, thus maintaining image quality and improving touch position detection accuracy.
Implementation Method 1
a common electrode that forms a capacitance with the pixel electrode
Implementation Method 2
a detection electrode that forms a capacitance with the drive electrode
Data Source
AI summary
A touch panel-equipped display device includes at least: a display control unit to supply a scan signal and a data signal to a display control element; and a touch position detection control unit to supply a drive signal to a drive electrode, and to detect a position detection signal from a detection electrode to detect a touch position. The display control unit supplies the data signal sequentially to a plurality of display control elements connected respectively to a plurality of pixel electrodes constituting one display pixel. The touch position detection control unit starts supplying the drive signal, in a period that is within a scan write period during which the scan signal is supplied to the display control element and is other than a period during which the data signal is supplied to the display control element corresponding to a color highest in luminosity of a plurality of colors.