Integrated Touch Electrodes in Organic EL Displays
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Solution Overview
Problem
The integration of a touch panel into an organic EL display device increases its thickness, compromising the thinness and flexibility advantages of the self-luminous organic EL display device.
Innovation Solution
An organic EL display device with a built-in touch panel is designed, where a first electrode of the touch panel extends above a pixel on a TFT substrate via an insulation film, and a counter substrate covers it, while a second electrode of the touch panel extends on the outer side of the counter substrate, allowing for capacitance detection without adding significant thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a touch panel is mounted onto the organic EL display device, then touch functionality is achieved, but the device thickness increases
Solution Approach 1:
The patent merges the touch panel structure with the organic EL display device by integrating the first electrode above the pixel and the counter substrate as the second electrode, creating a unified structure that provides both display and touch functionality without requiring a separate mounted touch panel
Solution Approach 2:
The counter substrate serves dual functions as both the protective cover for the organic EL display and the second electrode for touch panel operation, eliminating the need for additional components and maintaining thinness
2Adaptability or versatility
If a separate touch panel is added to the organic EL display device, then touch capability is provided, but the thinning advantage of organic EL display is compromised
Solution Approach 1:
The touch panel electrodes are merged into the display structure itself, with the first electrode positioned above the pixel and the counter substrate serving as the second electrode, creating an integrated thin structure that maintains the inherent thinness advantage of organic EL displays
Solution Approach 2:
The touch panel electrodes are nested within the existing display structure layers, with the first electrode embedded above the pixel and the counter substrate serving dual purposes, allowing touch functionality to be contained within the display thickness rather than adding to it
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 configuration maintains the thinness and flexibility of the organic EL display device while enabling touch functionality by detecting capacitance changes between electrodes, allowing for precise touch position sensing without increasing the device's overall thickness.
Implementation Method 1
a first electrode of a touch panel extends above the pixel in the first direction via an insulation film... allowing for capacitance detection
Data Source
AI summary
An EL display device includes a TFT substrate on which a scanning line extends in a first direction, a video signal line extends in a second direction, and an EL element having an anode, a luminous layer and a cathode. A protective film covers the scanning line, the video signal line and the EL element. A touch panel detection electrode is disposed above the protective film, and connected to a wiring which is disposed under the protective film via a through hole of the protective film. The touch panel detection electrode has an angle to intersect with the video signal line.