OLED Panel Touch Sensing via Waveguide Frustrated Total Internal Reflection
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Solution Overview
Problem
Existing touch-screen technologies for flat panel displays are cumbersome due to mechanical mounting, increase the number of parts, weight, and manufacturing cost, and fail to accurately sense multi-touch positions.
Innovation Solution
An organic light-emitting diode (OLED) panel with a waveguide and integrated OLED sensors that utilize frustrated total internal reflection to detect touch positions, allowing for multi-touch recognition without additional mechanical components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate touch-screen device is mechanically mounted to the display panel, then touch-screen functionality is achieved, but the number of parts, weight, manufacturing cost, and thickness increase
Solution Approach 1:
The patent combines the touch-screen sensing function with the OLED display panel by integrating OLED sensors into the same substrate. The OLED sensors are positioned adjacent to sub-pixel regions and share the same structural layer (including electrodes and organic layers), eliminating the need for separate mechanical mounting of touch-screen devices.
Solution Approach 2:
The OLED panel serves dual functions: display functionality through sub-pixel OLEDs and touch sensing through sensing region OLEDs. Both functions are achieved within a single integrated structure, allowing the panel to act as both display and touch-screen device simultaneously.
2Reliability
If a separate touch-screen device is mechanically mounted to the display panel, then touch-screen functionality is achieved, but weight increases
Solution Approach 1:
The touch-screen sensing function is merged with the display panel structure, eliminating the need for separate touch-screen components that would add weight. The OLED sensors are integrated into the same substrate and share structural elements with the display OLEDs.
3Reliability
If a separate touch-screen device is mechanically mounted to the display panel, then touch-screen functionality is achieved, but manufacturing cost increases
Solution Approach 1:
The patent integrates touch sensing and display functions into a single manufacturing process. Both sub-pixel OLEDs and sensing OLEDs are fabricated on the same substrate using the same structural layers (first electrode, organic layers, second electrode), reducing manufacturing complexity and cost compared to assembling separate components.
4Reliability
If a separate touch-screen device is mechanically mounted to the display panel, then touch-screen functionality is achieved, but thickness increases
Solution Approach 1:
The touch sensing function is integrated within the same structural layers as the display function. The OLED sensors share the substrate, electrodes, and organic layers with the display OLEDs, eliminating the need for additional thickness from separate touch-screen components.
5Reliability
If related art touch-screen displays are used, then touch sensing is achieved, but multi-touch positions cannot be accurately sensed
Solution Approach 1:
The patent divides the OLED panel into multiple independent sensing regions, each with its own OLED sensor that can independently detect touch events. This segmentation allows simultaneous detection of multiple touch positions across different regions of the panel.
Solution Approach 2:
Each sensing region has localized OLED sensors positioned adjacent to specific sub-pixel regions, enabling precise determination of touch positions. The local sensing capability allows accurate identification of where touches occur on the display surface.
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
The OLED panel achieves accurate multi-touch recognition while being lightweight and cost-effective, reducing the number of mechanically attached parts and enabling thin, efficient flat panel displays.
Implementation Method 1
a waveguide with a light substantially totally reflected therein
Implementation Method 2
the second light-emitting device responsive to a scattering of the light from the waveguide for outputting a signal indicative of a contact on the waveguide
Data Source
AI summary
A display device includes a waveguide with a light propagating therein, and a panel including a first organic light-emitting device in a sub-pixel region and a second organic light-emitting device in a sensing region adjacent to the sub-pixel region, the first organic light-emitting device for displaying a data on the panel, and the second light-emitting device responsive to a scattering of the light from the waveguide for outputting a signal indicative of a contact on the waveguide.