Integrated Pixel Circuit for In-Cell Touch AMOLED Displays
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Solution Overview
Problem
Current in-cell touch AMOLED display panels face challenges in integrating touch circuits and driving circuits due to limited space, leading to increased manufacturing costs and reduced aperture ratio.
Innovation Solution
A pixel circuit is designed with an integrated pixel compensation module, light emitting module, and touch detection module, sharing data voltage and scan signal lines to reduce the number of signal lines, thereby increasing pixel density and reducing IC costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If touch circuits and driving circuits are integrated into each pixel unit, then the in-cell touch function is achieved with thinner thickness and higher light transmittance, but the limited space in pixel units prevents simultaneous manufacture of both circuits
Solution Approach 1:
The patent merges the touch detection circuit and display driving circuit into a single integrated pixel circuit. The pixel circuit includes a pixel compensation module for display driving and a touch detection module for touch sensing, both sharing the same pixel unit space. This merging allows simultaneous manufacture of touch and display circuits within the limited pixel unit area, achieving in-cell touch functionality with reduced thickness and improved light transmittance.
Solution Approach 2:
The pixel circuit is designed with multi-functionality to serve both display driving and touch detection purposes. The pixel compensation module handles display signal processing while the touch detection module handles touch sensing, allowing a single pixel unit to perform multiple functions. This universal design enables the pixel circuit to adapt to both display and touch operations without requiring separate dedicated circuits.
2Adaptability or versatility
If multiple driving circuit TFTs are added to each pixel unit for in-cell touch function, then touch sensing capability is achieved, but the number of required pixel units increases occupying additional space
Solution Approach 1:
The touch detection module is merged with the pixel compensation module within the same pixel unit, eliminating the need for additional separate pixel units. The integrated design allows touch sensing TFTs to share the same physical space as display driving TFTs, maintaining touch capability while preventing increase in overall pixel unit area.
Solution Approach 2:
The patent utilizes the vertical dimension within the pixel unit by stacking TFTs in different layers. The touch detection TFTs are positioned in different vertical layers from the display driving TFTs, allowing both circuits to coexist within the same planar pixel unit footprint. This dimensional arrangement enables touch functionality without increasing the horizontal area of each pixel unit.
3Productivity
If the pixel circuit is optimized for integration, then the pixel pitch is decreased and pixel density is increased, but the manufacturing precision requirements increase due to tighter spacing
Solution Approach 1:
The pixel circuit is segmented into distinct functional modules: pixel compensation module with dedicated TFTs (T1-T6), touch detection module with dedicated TFTs (T7-T10), and energy storage capacitors. This segmentation allows each module to be independently optimized and manufactured, reducing the cumulative precision errors that would arise from trying to manufacture the entire circuit as a single integrated block. The modular design facilitates better control over manufacturing precision while maintaining high pixel density.
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 integration decreases pixel pitch, lowers IC costs, and enhances pixel density while maintaining the operation current unaffected by driving transistor threshold voltage variations, addressing issues of display brightness nonuniformity.
Implementation Method 1
the light emitting module comprises an electroluminescent element connected to the pixel compensation module
Data Source
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Figure 2b
AI summary
Disclosed are a pixel circuit and a display apparatus. The pixel circuit comprises a pixel compensation module (100), a light emitting module (200) and a touch detection module (300); the pixel compensation module (100) is connected to a first to a fourth scan signal lines (Scan[1], Scan[2], Scan[3], Em), a first operation voltage (Vdd), a data voltage (Vdata) and the light emitting module (200) respectively, and is configured to control the light emitting module (200) to emit light for display in accordance with inputs from the scan signal lines; the touch detection module (300) comprises a detection sub module (310) and an output sub module (320). The pixel compensation module (100) and the touch detection module (200) are integrated into the pixel circuit, and the pixel compensation module (100) and the touch detection module (200) share the data voltage (Vdata) and the scan signal line in common. In this way, the number of signal lines is decreased, thereby the pitch of pixels is largely decreased and IC cost is reduced, achieving a higher pixel density.