LCD White Pixels Voltage Optimization to Reduce Side Yellowing
Solution Overview
Problem
Liquid crystal displays (LCDs) with white pixels experience a yellowish phenomenon at the sides due to high refractive anisotropy, particularly when driving voltage increases, leading to reduced blue light transmission and compromised visibility.
Innovation Solution
The implementation of a liquid crystal display design where blue and white pixels operate at lower voltages than red and green pixels, achieved by varying channel widths and lengths of thin-film transistors, voltages applied to storage electrode lines, and subpixel electrode voltages, to reduce the yellowish phenomenon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If driving voltage is increased to improve visibility, then luminance is improved, but yellowish phenomenon at sides occurs due to high refractive anisotropy
Solution Approach 1:
The patent applies different voltage levels to different pixel types (blue and white pixels receive lower voltages than red and green pixels). This local differentiation in voltage application resolves the contradiction by preventing the yellowish phenomenon in pixels that are more sensitive to it, while maintaining adequate luminance in other pixels.
Solution Approach 2:
The patent changes the voltage parameter specifically for blue and white pixels, operating them at lower voltages to reduce the refractive anisotropy effect that causes yellowish phenomenon, while red and green pixels operate at higher voltages to maintain their luminance performance.
2Object-affected harmful factors
If blue light transmission is reduced to minimize yellowish phenomenon, then yellowish phenomenon is reduced, but visibility is compromised
Solution Approach 1:
The patent applies different voltage levels to different pixel types, with blue and white pixels operating at lower voltages to reduce yellowish phenomenon while red and green pixels operate at higher voltages to maintain visibility, thus resolving the contradiction through localized parameter optimization.
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 approach effectively minimizes the side yellowish phenomenon by optimizing the voltage distribution across different pixel types, enhancing visibility and reducing luminance issues at the sides of the LCD.
Implementation Method 1
A channel width of the third thin film transistor included in each of the red and green pixels is larger than a channel width of the third thin film transistor included in each of the blue and white pixels
Implementation Method 2
Liquid crystal displays (LCDs) with white pixels experience a yellowish phenomenon at the sides due to high refractive anisotropy
Data Source
AI summary
A display device includes red, blue, green, and white pixels, a plurality of gate lines, a plurality of data lines, and a plurality of storage electrodes lines. Each of the red, blue, green, and white pixels includes first to third thin film transistors, a first subpixel electrode connected to an output terminal of the first thin film transistor, and a second subpixel electrode connected to the output terminal of the second thin film transistor. A channel width of a third thin film transistor in each of the red and green pixels is larger than that of a third thin film transistor in each of the blue and white pixels, or a channel length of the third thin film transistor in each of the red and green pixels is longer than that of the third thin film transistor in each of the blue and white pixels.