Touch Display Device Metal Common Line Shielding
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Solution Overview
Problem
Current touch panels face limitations in touch sensitivity due to interference from display signals, which affects their performance and user experience.
Innovation Solution
A touch display device design featuring a pixel array substrate with specific arrangements of scan lines, data lines, metal common lines, pixel sets, and a common electrode layer, along with an opposite substrate including light-shielding patterns and touch electrode patterns, which prevents touch signal disturbance from display signals, enhancing touch sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional touch panel designs are used, then the structure is simple, but the touch sensitivity is limited due to interference from display signals
Solution Approach 1:
The touch panel is divided into distinct functional regions: a first region containing scan lines, data lines, and pixel electrodes for display functions, and a second region containing touch electrode patterns for touch sensing functions. This spatial segmentation allows independent optimization of display and touch performance, improving touch sensitivity by isolating touch signals from display signal interference.
Solution Approach 2:
The patent introduces a vertical layering dimension by placing the common electrode layer between the pixel array substrate and the opposite substrate, with touch electrode patterns on the opposite substrate. This three-dimensional arrangement separates touch and display functions in the vertical direction, enabling improved touch sensitivity without compromising display performance.
2Reliability
If the common electrode layer is integrated with the pixel array substrate, then the manufacturing process is simplified, but the touch signal is disturbed by display signals
Solution Approach 1:
The device is segmented into two separate substrates: the pixel array substrate containing display elements and the opposite substrate containing touch electrode patterns. The common electrode layer is positioned on the pixel array substrate but electrically isolated from pixel electrodes, creating distinct functional zones that prevent signal interference while maintaining manufacturability through standard multi-substrate assembly processes.
Solution Approach 2:
The common electrode layer acts as an intermediary element that is structurally connected to the pixel array substrate but electrically isolated from pixel electrodes through insulation layers. This intermediary structure prevents display signals from interfering with touch signals while maintaining the structural integrity and simplifying the manufacturing process.
3Reliability
If metal common lines are placed between scan lines, then the common voltage distribution is improved, but the touch area is reduced
Solution Approach 1:
The patent moves the common electrode functionality from the planar level (metal common lines on the same layer as scan lines) to a vertical level by placing the common electrode layer between the pixel array substrate and the opposite substrate. This vertical relocation eliminates the need for metal common lines that would occupy touch area, as the common electrode can be positioned in the inter-substrate space, maintaining voltage stability without reducing touch area.
Solution Approach 2:
The common electrode layer replicates the function of metal common lines for voltage distribution but does so in a different spatial location (between substrates rather than on the pixel array substrate). This copying approach maintains the essential function of common voltage distribution while eliminating the harmful occupation of touch area.
Data Source
AI summary
A touch display device including scan lines, data lines, metal common lines, pixel sets, a common electrode layer, light-shielding patterns and touch electrode patterns is provided. Each metal common line is located between two adjacent scan lines. Each pixel set is located between two adjacent metal common lines. The common electrode layer includes common electrode portions disposed corresponding to the metal common lines. A vertical projection of each metal common line is completely located within a vertical projection of the corresponding common electrode portion. The light-shielding patterns are disposed corresponding to the metal common lines, and a vertical projection of each metal common line and the scan lines adjacent thereto is completely located within a vertical projection of the corresponding light-shielding pattern. The touch electrode patterns are disposed corresponding to the metal common lines, and a vertical projection of each touch electrode pattern is completely located within a vertical projection of the corresponding common electrode portion.