Electro-optical Device Light-Shielding Film Transistor Optical Leakage
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Solution Overview
Problem
Existing electro-optical devices with active matrix drive types face challenges in preventing optical leakage currents, which can lead to device malfunctions, due to insufficient optical shielding of TFTs, particularly in the upper layers of storage capacitors.
Innovation Solution
The introduction of a light-shielding film between the pixel electrode and the second capacitor electrode, which is electrically connected and partially overlapped by the transistor, enhances optical shielding capabilities by using a material with higher light-shielding properties than the capacitor electrodes, and is configured to maintain a constant electric potential, forming a high-density storage capacitor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If storage capacitors are formed in the laminated structure with oxidized film electrodes, then pressure-withstanding capability is enhanced, but optical shielding capability deteriorates
Solution Approach 1:
The patent divides the storage capacitor structure into multiple segments: a first capacitor electrode with oxidized film for pressure resistance, and a second capacitor electrode with light-shielding material for optical shielding. This segmentation allows each component to specialize in one function, resolving the contradiction between pressure-withstanding capability and optical shielding capability.
Solution Approach 2:
The first capacitor electrode serves dual purposes: it provides mechanical strength through its oxidized film structure and simultaneously acts as part of the light-shielding system by being positioned between the TFT and the second capacitor electrode. This multi-functionality helps resolve the contradiction by making one component serve both protective roles.
2Object-affected harmful factors
If light-shielding film is added between pixel electrode and second capacitor electrode, then optical shielding capability is improved, but device complexity increases
Solution Approach 1:
The patent merges the light-shielding function with the capacitor electrode structure itself. The second capacitor electrode is formed using a light-shielding material, and the first capacitor electrode is positioned to provide additional shielding. This merging eliminates the need for separate light-shielding layers, reducing overall device complexity while maintaining optical shielding effectiveness.
Solution Approach 2:
The capacitor electrodes themselves provide the light-shielding function without requiring external light-shielding components. The oxidized film and light-shielding material in the capacitor structure serve dual purposes: electrical storage and optical protection. This self-service approach reduces device complexity by making existing components multi-functional.
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 effectively prevents optical leakage currents, thereby enhancing the reliability and image quality of the electro-optical device by providing robust optical shielding for the transistors and maintaining high-density storage capacitors.
Implementation Method 1
a light-shielding film configured to be provided between the pixel electrode and the second capacitor electrode, be located so as to be at least partially overlapped by the transistor
Data Source
AI summary
An electro-optical device includes a pixel electrode provided on a substrate, a transistor provided between the substrate and the pixel electrode, a first capacitor electrode provided between the pixel electrode and the transistor, and be electrically connected to the pixel electrode and the transistor, a second capacitor electrode provided between the pixel electrode and the first capacitor electrode, be located so as to be opposite the first capacitor electrode via a capacitor insulating film, and be supplied with a predetermined electric potential, and a light-shielding film provided between the pixel electrode and the second capacitor electrode, be located so as to be at least partially overlapped by the transistor, and be electrically connected to the second capacitor electrode via a contact hole formed in an insulating film disposed between the second capacitor electrode and the light-shielding film.