Reflective Metal OLED Lines for Sensor Light Transfer
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Solution Overview
Problem
In organic light emitting diode (OLED) displays, light emitted from pixels is often extinguished when transferred to an optical sensor unit for analysis and correction, leading to ineffective pixel deterioration compensation.
Innovation Solution
The OLED display incorporates a substrate with a gate line, data line, and driving voltage line formed from multiple layers, including a reflective metal layer and a transparent metal layer, along with light reflection patterns, to reflect and transfer light emitted from pixels to the optical sensor unit without absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional single-layer metal line structure is used, then the device complexity is low, but light emitted from pixels is extinguished during transfer to the optical sensor unit
Solution Approach 1:
The metal line structure is segmented into multiple layers with different functions: a lower reflective metal layer (aluminum, silver, or copper) to reflect light upward, and an upper transparent conductive oxide layer (ITO or IZO) to maintain electrical conductivity while allowing light transmission. This segmentation resolves the contradiction by preventing light extinction while maintaining structural functionality.
Solution Approach 2:
The patent employs composite material structure combining reflective metal (for light reflection) and transparent conductive oxide (for electrical conductivity and light transmission). This composite approach enables the line structure to simultaneously achieve light preservation and electrical functionality, resolving the technical contradiction between reducing light loss and maintaining device simplicity.
2Measurement precision
If light is transferred to the optical sensor unit for pixel analysis, then pixel deterioration can be detected, but light may be extinguished during transfer
Solution Approach 1:
The reflective metal layer acts as an intermediary element that redirects light from downward-emitting pixels upward toward the optical sensor unit. This intermediary structure ensures light reaches the sensor for accurate pixel deterioration detection without being extinguished, resolving the contradiction between measurement precision and light loss.
3Loss of energy
If the lowest layer of the line structure is made of reflective metal, then light is reflected to the optical sensor unit, but the structure becomes more complex
Solution Approach 1:
The multi-layer line structure serves multiple functions simultaneously: the reflective metal layer reflects light upward to prevent loss, the transparent conductive oxide layer maintains electrical conductivity, and the combined structure enables both display functionality and optical sensing. This multi-functionality justifies the increased structural complexity by resolving the light loss issue while integrating multiple capabilities.
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 prevents light loss, allowing for accurate detection and correction of deteriorated pixels by ensuring that light is efficiently transferred to the optical sensor unit, thereby maintaining image quality.
Implementation Method 1
a lowest layer of the plurality of layers comprises a first metal layer made of a reflective metal
Data Source
AI summary
An organic light emitting diode display includes: a substrate; a gate line on the substrate; a data line crossing the gate line; a driving voltage line extending parallel with at least one of the gate line and the data line; a first thin film transistor coupled to the gate line and the data line and comprising a first semiconductor layer; a second thin film transistor coupled to the first thin film transistor and the driving voltage line and comprising a second semiconductor layer; and an organic light emitting element coupled to the second thin film transistor, wherein at least one of the gate line, the data line, and the driving voltage line comprise a plurality of layers, and the lowest layer of the plurality of layers comprises a first metal layer made of a reflective metal.