Touch Screen Display Driving Circuit with Dynamic Period Segmentation
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Solution Overview
Problem
Current time division driving methods for touch screen display devices face limitations in enhancing touch performance and are plagued by touch latency and audible noise, particularly in methods like V_Blank and Long H_Blank, which affect the touch report rate and user experience.
Innovation Solution
A touch screen display device and driving circuit that dynamically adjust display and touch periods within a frame, allowing for varied lengths of display and touch periods, including multiple touch periods between display periods, to improve touch performance and minimize audible noise, utilizing a common electrode for both display and touch functions without additional processing for touch electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If time division driving method is used to enhance touch performance, then touch sensitivity is improved, but touch latency increases
Solution Approach 1:
The frame period is segmented into multiple display periods and touch periods, allowing touch sensing to occur during display periods rather than requiring separate dedicated touch periods. This segmentation enables overlapping of display and touch operations, improving touch responsiveness while maintaining display quality.
Solution Approach 2:
The patent implements periodic touch sensing within display periods by applying touch driving signals at regular intervals during the display period. This periodic action allows continuous touch monitoring without interrupting the display operation, reducing touch latency while maintaining sensitivity.
2Productivity
If touch period is extended to improve touch report rate, then touch report rate increases, but display period is reduced
Solution Approach 1:
The patent merges display period and touch period functions by performing touch sensing operations during the display period. The touch driver applies touch driving signals to touch electrodes while the display driver simultaneously drives the display, combining both functions in the same time period rather than requiring separate periods.
Solution Approach 2:
Touch sensing is performed periodically within the display period through multiple touch sensing operations. This allows the system to achieve high touch report rates by conducting multiple touch measurements during what would traditionally be a single display period, without sacrificing display quality.
3Object-affected harmful factors
If multiple touch periods are implemented to reduce audible noise, then audible noise decreases, but device complexity increases
Solution Approach 1:
The common electrode serves multiple functions: it acts as a display electrode during display periods and as a touch sensing electrode during touch periods. This multi-functionality eliminates the need for separate touch electrodes, reducing device complexity while enabling multiple touch periods for noise reduction.
Solution Approach 2:
The electrode configuration is dynamically switched between display mode and touch sensing mode through time-division multiplexing. The same physical electrode structure performs different functions at different times, allowing multiple touch periods without requiring additional hardware complexity.
Data Source
AI summary
Disclosed is a touch screen display device. The touch screen display device includes a first driver displaying an image on a first area of a display panel during a first display period and displaying an image on a second area of the display panel during a second display period and a second driver applying a touch driving signal to a third area of the display panel during a first touch period. A length of the first display period and a length of the second display period are differently set in LHB driving. Accordingly, audible noise is minimized, and touch latency is fast.