Display Device Driving Method for Optical Touch Signal Interference
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Solution Overview
Problem
Conventional optical touch control LCDs face interference between data signals and sensing signals due to parasitic elements coupling between pixel circuits and optical sensing circuits, which are manufactured on the same layer, leading to signal disturbance.
Innovation Solution
A display device driving method that selectively couples a node point with either the source driving circuit or the reading circuit, using control signals to enable pixel and optical sensing circuits to receive and output signals without overlapping impulses, thereby amplifying and outputting sensing signals while minimizing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If pixel circuits and optical sensing circuits are manufactured on the same layer, then device complexity is reduced and manufacturing is simplified, but signal interference occurs between data signals and sensing signals due to parasitic elements
Solution Approach 1:
The patent divides the signal transmission path into separate physical paths by routing data signals through a data line and sensing signals through a sensing line, even though both circuits are on the same layer. This spatial segmentation prevents parasitic coupling between the two signal types, resolving the interference problem while maintaining the simplified single-layer structure.
Solution Approach 2:
The patent introduces a sensing transistor as an intermediary component that couples the sensing line to the sensing electrode. This intermediary element allows the sensing signal to be transmitted through the same layer without directly interfering with the data line, as the sensing transistor acts as a controlled bridge that isolates the two signal paths when not actively sensing.
2Device complexity
If data signal and sensing signal share the same node point, then device complexity is reduced, but signal disturbance occurs due to parasitic element coupling
Solution Approach 1:
The patent segments the node point into functionally separate connection points: one for data signal input to the pixel circuit and another for sensing signal output from the optical sensing circuit. Although physically located at the same position on the substrate, these segmented connections are activated at different times through selective coupling, preventing signal disturbance while maintaining structural simplicity.
Solution Approach 2:
The patent employs periodic switching of the coupling between the node point and different circuits. During display operation, the node point couples with the data line; during touch sensing operation, it couples with the sensing line. This periodic action ensures that only one signal type is active at any given time, eliminating interference while allowing shared use of the node point infrastructure.
3Object-affected harmful factors
If selective coupling is implemented between node point and source driving circuit or reading circuit, then signal interference is reduced, but control complexity increases
Solution Approach 1:
The patent makes the node point multi-functional by enabling it to serve both as a data signal input point and a sensing signal output point through selective coupling. The same physical node point structure performs different functions at different times, controlled by switching signals that activate the appropriate coupling path. This universal design reduces the need for separate dedicated paths while maintaining signal isolation.
Solution Approach 2:
The patent introduces dynamic switching capability to the node point coupling mechanism. The coupling between the node point and the circuits it connects to is not fixed but dynamically adjustable through control signals. This dynamic property allows the system to adapt the electrical connection configuration in real-time, enabling interference-free operation during both display and sensing modes without requiring permanently separate physical paths.
Data Source
AI summary
A display device driving method, applicable to a display device including a pixel circuit coupled with a first node point, a source driving circuit for providing a data signal, and a reading circuit, including following operations: coupling the first node point with the source driving circuit or the reading circuit; supplying a first control signal to the pixel circuit, wherein the first control signal is for enabling the pixel circuit to receive the data signal from the first node point; supplying a second control signal to an optical sensing circuit, wherein the second control signal is for enabling the optical sensing circuit to output a sensing signal to the reading circuit through the first node point; utilizing the reading circuit to amplify the sensing signal and output the amplified sensing signal, wherein duration of the second impulse overlaps with duration of the first impulse.