Three-Layer Black Electrode Structure for LCD Touch Displays
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Solution Overview
Problem
Existing liquid crystal display devices with touch sensing functions face challenges in achieving high aperture ratio, low reflectance, and improved visibility due to issues with light shielding properties and alignment of black matrix patterns, particularly in high-definition displays, where thin line widths and precise photolithography are difficult to maintain, leading to reduced transmittance and increased noise in touch sensing operations.
Innovation Solution
A liquid crystal display device configuration featuring a three-layer black electrode structure comprising a light absorptive resin layer, a metal layer, and a second light absorptive resin layer, with the metal layer patterned in a frame shape to enhance light shielding and reduce reflectance, and transparent electrode patterns aligned perpendicular to the metal layers to improve touch sensing accuracy and visibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a black matrix is formed with a large thickness to obtain high light shielding properties, then light shielding performance is improved, but the line width must be increased which reduces manufacturing precision for high-definition displays
Solution Approach 1:
The patent uses a composite structure consisting of a light absorptive resin layer and a metal layer. The light absorptive resin layer provides light shielding properties while the metal layer enhances both light shielding and electrical conductivity for touch sensing. This composite approach allows achieving high light shielding performance without increasing the overall thickness beyond manufacturing capabilities for thin line widths
Solution Approach 2:
The patent changes the material composition parameters by introducing a metal layer with specific optical and electrical properties. The metal layer has high reflectance that, when combined with the light absorptive resin layer, creates a black appearance with enhanced light shielding. This parameter change allows maintaining thin line widths while achieving required light shielding performance
2Manufacturing precision
If the line width of black matrix is reduced to achieve high definition, then pixel density is improved, but light shielding properties deteriorate
Solution Approach 1:
The composite structure of light absorptive resin layer and metal layer works synergistically to provide enhanced light shielding in a thin configuration. The metal layer's high reflectance combined with the resin layer's absorption creates effective light blocking without requiring increased thickness, thus maintaining thin line widths for high-definition displays
Solution Approach 2:
The metal layer serves multiple functions: it provides light shielding enhancement, electrical conductivity for touch sensing, and structural support. This multi-functionality allows a single thin layer to compensate for the reduced light shielding capability caused by thinner dimensions, achieving both high definition and adequate light shielding
3Device complexity
If a single layer structure is used for touch sensing electrode, then device complexity is reduced, but electrical conductivity and touch sensing performance deteriorate
Solution Approach 1:
The metal layer is designed to serve dual purposes: as part of the black matrix structure for light shielding and as the touch sensing electrode. This multi-functionality reduces the need for separate electrode layers while maintaining touch sensing performance through the inherent electrical conductivity of the metal material
Solution Approach 2:
The composite structure provides both optical functions (light shielding through resin layer and reflection through metal layer) and electrical function (touch sensing through metal layer conductivity). This integration of multiple functions in a composite structure achieves adequate touch sensing performance without significantly increasing device complexity
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 configuration increases the aperture ratio, enhances transmittance, and provides improved visibility and accuracy in touch sensing by reducing retroreflection and diffused reflection, while supporting higher definition pixel sizes and stylus input capabilities.
Implementation Method 1
a plurality of first light absorptive resin layer patterns 1, a plurality of metal layer patterns 2, and a plurality of second light absorptive resin layer patterns 3 are laminated in this order on a main surface 10a of a first transparent substrate 10
Implementation Method 2
the metal layer patterned in a frame shape to enhance light shielding and reduce reflectance
Implementation Method 3
the touch sensing function at least includes setting the plurality of the transparent electrode patterns 6 to a constant electrical potential, applying a touch driving voltage across the plurality of transparent electrode patterns 6 and the plurality of metal layer patterns 2, and detecting a change in electrostatic capacitance across the metal layer patterns 2 and the transparent electrode patterns 6
Implementation Method 4
a liquid crystal layer 24; and an array substrate 23 laminated in this order
Data Source
AI summary
In a liquid crystal display device, a plurality of first light absorptive resin layer patterns, a plurality of metal layer patterns, a plurality of second light absorptive resin layer patterns, a transparent resin layer, and a plurality of transparent electrode patterns are laminated in this order on a surface of a first transparent substrate facing a liquid crystal layer; the plurality of the first light absorptive resin layer patterns, the plurality of the metal layer patterns, and the plurality of the second light absorptive resin layer patterns have openings formed therein, and are formed into the same shape when viewed in a laminating direction; the plurality of the metal layer patterns are arrayed in a first direction, being insulated from each other, the plurality of the transparent electrode patterns are arrayed in a second direction perpendicular to the first direction, being insulated from each other.