Photo-Sensitive TFT Touch Detection in LCD Active Matrix
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Touch screens for liquid crystal displays often compromise display contrast, increase manufacturing costs, and complexity due to the addition of transparent surfaces and additional layers for touch detection, leading to glare and reduced manufacturing yield.
Innovation Solution
Incorporating a photo-sensitive structure within the active matrix layer of the liquid crystal display, using photo-sensitive thin film transistors and readout transistors with a black matrix to detect touch events without additional touch panel layers, thereby maintaining display integrity and reducing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a transparent surface and additional layers are added for touch detection, then touch sensitivity is improved, but display contrast deteriorates and glare increases
Solution Approach 1:
The patent merges the touch detection function with the display's active matrix layer by incorporating photo-sensitive thin film transistors directly into the display structure. This integration eliminates the need for separate transparent touch panels, thereby maintaining display contrast while enabling touch sensitivity through the detection of light blocking events at transistor locations.
Solution Approach 2:
The active matrix layer is designed to serve dual functions: displaying visual information and detecting touch events. The photo-sensitive transistors within the active matrix layer can both control display pixels and sense touch by detecting changes in light transmission,从而实现一材多用，避免增加额外的触摸面板层。
2Adaptability or versatility
If additional touch panel layers are added, then touch detection capability is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple functions into a single integrated structure. The active matrix layer incorporates photo-sensitive transistors that simultaneously serve as display control elements and touch sensors, eliminating the need for separate touch panel layers and reducing overall device complexity.
Solution Approach 2:
The photo-sensitive transistors in the active matrix layer perform multiple functions: they control the display pixels during normal operation and detect touch events when light blocking occurs. This multi-functionality reduces the need for additional dedicated touch detection components, thereby simplifying the overall device structure.
3Ease of operation
If additional touch panel layers are added, then touch sensitivity is improved, but manufacturing yield decreases
Solution Approach 1:
The patent merges touch detection functionality into the existing active matrix manufacturing process. By using the same thin film transistor fabrication techniques to create photo-sensitive transistors, the display can be manufactured in a single production line without requiring separate assembly steps for touch panels, thereby maintaining high manufacturing yield.
4Device complexity
If photo-sensitive structures are integrated into the active matrix layer, then touch detection is enabled without additional layers, but manufacturing precision requirements increase
Solution Approach 1:
The patent modifies the electrical characteristics of existing thin film transistors by incorporating light-sensitive materials into their structure. This parameter change enables the transistors to respond to light blocking events while maintaining compatibility with standard thin film transistor fabrication processes, balancing manufacturing precision requirements with enhanced functionality.
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 solution allows for touch detection without degrading display contrast or increasing complexity, maintaining manufacturing yield while integrating touch functionality directly into the display's active matrix layer.
Implementation Method 1
Incorporating a photo-sensitive structure within the active matrix layer of the liquid crystal display, using photo-sensitive thin film transistors and readout transistors with a black matrix to detect touch events
Data Source
AI summary
A light sensitive display.