Liquid Crystal Display Touch Electrode with Light Absorptive Resin
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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 good visibility due to issues with light shielding properties, electrode resistance, and alignment accuracy, particularly in high-definition displays.
Innovation Solution
A liquid crystal display device configuration with a transparent substrate, light absorptive resin layer patterns, and metal layer patterns of equal line width, aligned and laminated to form a black electrode, combined with transparent electrode patterns for touch sensing, using copper-based alloys for low resistance and high light shielding, and a control unit for differential voltage frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a black matrix with large thickness (1 μm or more) is used to achieve high light shielding properties, then optical density improves, but aperture ratio deteriorates
Solution Approach 1:
The patent uses a composite structure combining a light absorptive resin layer (containing carbon black or other pigments) with a transparent conductive oxide layer (such as ITO or IZO). This composite approach allows the light absorptive layer to provide optical density while the transparent conductive layer provides electrical conductivity for touch sensing, eliminating the need for thick opaque black matrices and thereby improving aperture ratio while maintaining light shielding properties.
Solution Approach 2:
The patent changes the optical parameters by using light absorptive resin layers with controlled thickness (0.5-2.0 μm) and specific optical density values (0.5-1.5), combined with transparent conductive oxide layers. This parameter optimization allows achieving sufficient light shielding without the need for thick opaque layers, thus improving aperture ratio while maintaining display contrast.
2Manufacturing precision
If black matrix lines are made thinner (4 μm or less) to achieve high definition, then pixel density improves, but light shielding properties deteriorate
Solution Approach 1:
The patent employs a composite structure where a light absorptive resin layer (providing optical density) is combined with a transparent conductive oxide layer. This allows thin line widths (4 μm or less) to be used for high-definition displays while maintaining sufficient light shielding properties through the light absorptive material, rather than relying solely on increased thickness.
Solution Approach 2:
The patent optimizes parameters by controlling the thickness (0.5-2.0 μm) and optical density (0.5-1.5) of the light absorptive resin layer, allowing thin black matrix lines to achieve adequate light shielding performance for high-definition displays with 200 ppi or more.
3Illumination intensity
If a transparent conductive oxide layer is used for touch sensing, then transparency improves, but electrical conductivity deteriorates
Solution Approach 1:
The patent uses a composite structure where a transparent conductive oxide layer (such as ITO or IZO) is combined with a light absorptive resin layer. The transparent conductive oxide provides both transparency and electrical conductivity, while the light absorptive layer provides optical density. This composite approach overcomes the limitation of transparent conductive oxides having insufficient conductivity alone, enabling effective capacitive touch sensing with low resistance.
4Manufacturing precision
If two-step photolithography is used to form thin black matrix lines, then alignment accuracy improves, but manufacturing complexity increases
Solution Approach 1:
The patent forms the black matrix and touch sensing electrode simultaneously as a composite structure using single-step photolithography. The light absorptive resin layer and transparent conductive oxide layer are patterned together, eliminating the need for complex two-step photolithography processes while maintaining alignment accuracy and reducing manufacturing complexity.
Data Source
AI summary
A liquid crystal display device with a surface of a first transparent substrate, the surface of the substrate facing a liquid crystal layer, a plurality of light absorptive resin layer patterns, a plurality of metal layer patterns, a transparent resin layer, and a plurality of transparent electrode patterns are laminated in this order; the plurality of light absorptive resin layer patterns and the plurality of metal layer patterns have openings formed therein and formed into the same shape when viewed in a laminating direction; the plurality of metal layer patterns are arrayed in a first direction, being insulated from each other; the plurality of transparent electrode patterns are arrayed in a second direction perpendicular to the first direction, being insulated from each other; each metal layer pattern has at least one of an alloy layer mainly containing copper, and a copper layer.