OLED Touch Panel Integration via Shared TFT Processes
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Solution Overview
Problem
Current organic light emitting diode (OLED) display devices lack an integrated touch panel functionality, limiting their ability to provide both display and touch sensing capabilities in a single device.
Innovation Solution
A method and structure for an OLED touch panel that includes defining pixel and light sensing regions on a substrate, forming thin film transistors and electrodes, and integrating an optical sensor with a silicon-rich dielectric layer to enable touch sensing, allowing for the integration of touch panel functionality into OLED display devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If OLED display device is used, then power saving and wide view angle are achieved, but touch panel functionality is not integrated
Solution Approach 1:
The patent combines the OLED display structure with touch sensor electrodes into a single integrated device. The touch sensor electrodes are formed between the substrate and the OLED structure, allowing both display and touch sensing functions to coexist in one device without requiring separate touch panel layers, thereby achieving functionality integration while controlling structural complexity
Solution Approach 2:
The OLED display device is designed to perform multiple functions: light emission for display and touch sensing through integrated electrodes. The same device structure serves both as the light-emitting display component and as the touch sensor, eliminating the need for separate dedicated touch panel components
2Adaptability or versatility
If separate touch panel is added to OLED, then touch sensing is enabled, but manufacturing complexity increases
Solution Approach 1:
The touch sensor electrodes are formed using the same thin-film transistor fabrication processes as the OLED driving circuits. The electrodes are created during the OLED manufacturing sequence, sharing process steps such as sputtering and patterning, which eliminates the need for separate touch panel manufacturing lines and simplifies production
Solution Approach 2:
The touch sensor electrodes are formed early in the manufacturing process, before the OLED functional layers are deposited. This preliminary formation of electrodes allows subsequent OLED layers to be built around them, enabling both components to be manufactured in a single integrated process flow rather than requiring separate assembly steps
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
Enables the effective integration of touch sensing into OLED display devices, offering improved opto-electronic characteristics, a larger fill factor, and easier manufacturing integration, while maintaining the advantages of OLED technology such as power saving and wide view angles.
Implementation Method 1
integrating an optical sensor with a silicon-rich dielectric layer to enable touch sensing
Data Source
AI summary
A display region and a light sensing region are defined in each pixel region of the OLED touch panel of the present invention. The readout thin film transistor of the light sensing region is formed by the same processes with the drive thin film transistor of the display region. The top and bottom electrodes of the optical sensor are formed by the same processes with the top and bottom electrodes of the OLED. Accordingly, the present invention can just add a step of forming the patterned sensing dielectric layer to the processes of forming an OLED panel to integrate the optical sensor into the pixel region of the OLED panel. Thus, an OLED touch panel is formed.