LCD Conductive Patterns for Laser Repair and Viewing Angle
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Solution Overview
Problem
LCDs with polarizers and high dielectric liquid crystal layers face challenges in repair due to light leakage and require higher voltages to display defective pixels as black, affecting viewing angle and repair success ratio.
Innovation Solution
The LCD design includes conductive patterns that overlap with data lines and pixel electrodes, allowing for laser welding to connect these patterns with the pixel electrode, forming a floating state and increasing capacitance, which enables effective repair without light leakage and at lower voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a polarizer with discotic liquid crystal layer is inserted to improve viewing angle, then viewing angle is improved, but light leakage occurs and repair recognition by user increases
Solution Approach 1:
The patent extracts the problematic discotic liquid crystal layer from the polarizer structure and replaces it with a different liquid crystal material that does not cause excessive retardation. This removes the harmful light leakage effect while preserving the wide viewing angle capability through alternative optical design means.
Solution Approach 2:
The patent changes the material parameter of the liquid crystal layer from discotic to non-discotic type, fundamentally altering the optical properties to eliminate harmful retardation effects while maintaining desirable viewing angle characteristics.
2Speed
If a liquid crystal layer with high dielectric constant is used, then response time is improved, but higher voltage (5V or more) is required to display defective pixel as black
Solution Approach 1:
The patent changes the dielectric constant parameter of the liquid crystal layer to a lower value, which directly reduces the voltage requirement for pixel operation. This parameter modification allows the display to operate at lower voltages while maintaining adequate response time performance.
3Ease of repair
If conventional repair method is used with gate line and pixel electrode connection, then defective pixel is repaired, but light leakage occurs and repair is not successfully hidden
Solution Approach 1:
The patent extracts the problematic gate line connection method from the repair process and replaces it with a different approach using conductive patterns and data lines. This alternative repair method eliminates the light leakage issue that occurs with conventional gate line connection while maintaining repair functionality.
Solution Approach 2:
The patent employs temporary conductive patterns and data line connections as disposable repair elements that can be easily implemented and removed. These temporary structures enable the repair process without causing permanent light leakage, allowing for successful hidden repairs.
4Ease of repair
If conductive patterns overlap with data lines and pixel electrodes, then laser welding enables effective repair, but device structure becomes more complex
Solution Approach 1:
The patent makes the conductive patterns serve multiple functions: they act as both structural elements of the display device and as repair interfaces for laser welding. This multi-functionality reduces the need for separate repair components, thereby reducing overall device complexity despite the added repair capability.
Solution Approach 2:
The patent merges the conductive patterns with existing data lines and pixel electrodes, combining multiple functions into integrated structures. This merging approach reduces the number of separate components and simplifies the overall device architecture while enabling effective laser welding repair.
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 solution improves the repair success ratio and maintains a wide viewing angle by stabilizing pixel voltage and reducing light leakage, allowing for efficient darkening of defective pixels at lower voltages.
Implementation Method 1
Liquid crystal displays ('LCDs') display an image by adjusting light transmittance of liquid crystal with dielectric anisotropy using an electric field
Implementation Method 2
a gate line of a previous stage used as an electrode of a capacitor in a previous-stage storage capacitor method and the pixel electrode are electrically connected by laser welding
Implementation Method 3
a liquid crystal layer having a high dielectric constant injected between the TFT substrate and the color filter substrate
Data Source
AI summary
The present invention provides a liquid crystal display (“LCD”), a method of manufacturing the same, and a method of repairing the same capable of obtaining a wide viewing angle and improving a success ratio of repair. The LCD includes a gate line, a first data line intersecting the gate line, a thin film transistor (“TFT”) connected with the gate line and the first data line, a pixel electrode connected with the TFT, a first conductive pattern partially overlapping with a first end of the pixel electrode, a second conductive pattern partially overlapping with a second end of the pixel electrode, and a storage capacitor, wherein at least one of the first conductive pattern and the second conductive pattern partially overlaps with the first data line adjacent to the first end of the pixel electrode and a second data line adjacent to the second end of the pixel electrode, respectively.