Transparent OLED Touch Sensor Electrode Placement
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Solution Overview
Problem
Transparent OLED devices face challenges in maintaining transparency and reducing thickness while incorporating touch sensor functionality, as opaque metal wirings and touch screen panels increase thickness and affect transmissivity.
Innovation Solution
The design includes a substrate with sub-pixel and transparent regions, where the touch sensor electrode is placed in the transparent region, and touch sensor wiring is used to connect the electrode to an external device, allowing for contact sensing without overlapping with the sub-pixel region, thereby reducing thickness and maintaining transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a touch screen panel is disposed on the transparent OLED device to sense user contact, then the touch sensing function is achieved, but the thickness of the device is increased
Solution Approach 1:
The patent merges the touch sensor electrode with the transparent OLED device structure by directly forming the touch sensor electrode on the transparent region of the OLED device substrate. This integration eliminates the need for a separate touch screen panel, achieving touch sensing functionality while avoiding additional thickness increase.
Solution Approach 2:
The transparent region of the OLED device serves dual functions: it maintains optical transparency for the display function while simultaneously housing the touch sensor electrode for touch sensing. This multi-functionality allows the same structural element to fulfill both display and sensing roles without requiring additional components.
2Reliability
If opaque metal wirings are used to connect touch sensor electrodes, then electrical connection is achieved, but the transmissivity of the device is reduced
Solution Approach 1:
The patent changes the material parameter of the wiring from opaque metal to transparent conductive material. This parameter change allows the wiring to maintain electrical conductivity while being transparent to light, thus preserving the transmissivity of the device in the transparent region.
Solution Approach 2:
The patent employs transparent conductive materials that combine electrical conductivity with optical transparency. These composite materials enable the wiring to function as both an electrical conductor and an optical transmitter, resolving the conflict between electrical connection and light transmission.
3Length of stationary object
If the touch sensor electrode is disposed in the transparent region, then the device thickness is reduced and transparency is maintained, but the wiring resistance may increase
Solution Approach 1:
The patent optimizes the thickness parameter of the transparent conductive wiring to balance transparency and electrical conductivity. By carefully controlling the wiring thickness, the patent achieves both reduced device thickness in the transparent region and acceptable wiring resistance for reliable electrical connection.
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 enables the OLED device to sense user contact while minimizing thickness and preserving transparency, reducing manufacturing costs and wiring resistance, and allowing for simultaneous formation of touch sensor electrodes with existing electrodes.
Implementation Method 1
the touch screen panel of the self-capacitance method may include a plurality of touch sensor electrodes and touch sensor wirings connected to the touch sensor electrodes respectively, and the touch screen panel may sense a change in capacitance which is generated in the touch sensor electrodes
Data Source
AI summary
An organic light emitting display device includes a substrate, a pixel structure, and a touch sensor electrode. The substrate includes a sub-pixel region and a transparent region. The pixel structure is disposed in the sub-pixel region on the substrate. The touch sensor electrode is disposed in the transparent region on the substrate.