Source Driver IC Noise Reduction for Touch Pen Compatibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current touch ICs for liquid crystal displays, particularly those using low temperature poly-silicon technology, face issues with noise levels exceeding specified limits, affecting the matching and application with touch pens across different panel architectures.
Innovation Solution
A noise reduction module is integrated into the source driver IC (SD IC) of the display device, which stores and outputs compensating voltages based on noise storage and output control signals, with a phase delay, to manage noise levels and improve pixel voltage delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LTPS technology with MUX architecture is used in touch IC, then high-end product positioning is achieved, but noise levels exceed specification limits
Solution Approach 1:
The patent extracts the noise compensation function from the main pixel driving function by implementing a separate noise reduce module. This module independently measures noise on source lines and generates compensation voltages, separating the noise reduction function from the primary display function to effectively address noise issues while maintaining touch pen compatibility
Solution Approach 2:
The patent introduces a compensating voltage as an intermediary element between the noise measurement and the pixel driving. The noise reduce module generates compensation voltages based on measured noise levels, and these compensation voltages are then applied to offset the noise effects, acting as a mediator to eliminate the harmful noise without directly modifying the main driving signal path
2Object-affected harmful factors
If noise compensation is implemented during pixel voltage output, then noise levels are reduced, but additional control signals and timing coordination are required
Solution Approach 1:
The patent implements periodic noise measurement and compensation by controlling the noise reduce module to measure noise on source lines during specific time periods when no pixel voltages are being output. The measurement control signal activates the noise measurement function periodically, and the compensation is applied in subsequent periods, creating a rhythmic measurement-compensation cycle that simplifies timing coordination
Solution Approach 2:
The patent performs noise measurement in advance during periods when pixel voltages are not being output, before the compensation is actually needed. The noise reduce module measures noise levels on source lines during idle periods, stores the measurement results, and then applies the appropriate compensation in subsequent pixel driving periods, allowing the system to prepare compensation data beforehand without interfering with active display operation
Data Source
AI summary
The present invention relates to a display device comprising: a display panel having a plurality of pixels and a plurality of source lines, wherein each of the pixels is electrically connected to a respective source line; and an SD IC for providing pixel voltages and receiving a noise storage control signal and a noise output control signal; characterized in that the SD IC further comprises a noise reduce module to store voltage levels of the pixel voltages as compensating voltages based on the noise storage control signal and to output the compensating voltages based on the noise output control signal, wherein during a normal period, the SD IC outputs the pixel voltages to the pixels; during a compensation period, the SD IC outputs the compensating voltages to the pixels; wherein the noise output control signal is phased-delayed with respect to the noise storage control signal.