LCD Subpixel Voltage Control for Gray Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal displays (LCDs) in vertical alignment mode face challenges in maintaining accurate gray expression and preventing transmittance deterioration, especially at low gray levels, leading to color tone changes and side visibility issues.
Innovation Solution
The design includes a liquid crystal display with first and second pixels displaying different colors, each featuring sub-pixel electrodes on a substrate with specific voltage ratios and overlapping regions, along with insulating layers and switching elements, to control the electric field intensity across the liquid crystal layer, ensuring accurate gray representation and minimizing transmittance differences between front and side visibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If one pixel is divided into two subpixels with different transmittance to create side visibility, then side visibility is improved, but luminance increases at low gray and high gray levels making gray expression difficult
Solution Approach 1:
The pixel is divided into two subpixels with different transmittance characteristics. The first subpixel has higher transmittance and the second subpixel has lower transmittance, allowing independent control of luminance levels to achieve both side visibility and accurate gray expression
Solution Approach 2:
Different regions of the pixel (subpixels) are given different optical properties (transmittance). The first subpixel region has higher transmittance while the second subpixel region has lower transmittance, enabling localized optimization for both side visibility and gray level accuracy
2Ease of operation
If different transmittance is applied to subpixels to improve side visibility, then side visibility is improved, but color tone changes due to color display deviation
Solution Approach 1:
Different subpixel regions are assigned different transmittance values to optimize side visibility while maintaining color accuracy. The first subpixel has higher transmittance and the second subpixel has lower transmittance, with voltages controlled to prevent color tone changes
Solution Approach 2:
The transmittance parameter is varied across different subpixel regions by applying different voltages. This allows optimization of side visibility while maintaining accurate color display by controlling the voltage ratios applied to each subpixel
3Measurement precision
If voltage ratios are adjusted to improve gray expression, then gray expression accuracy is improved, but transmittance deterioration occurs
Solution Approach 1:
The voltage parameters applied to subpixels are optimized to achieve accurate gray expression. By controlling the ratio of voltages applied to the first and second subpixels, the system achieves precise gray levels while maintaining stable transmittance characteristics
Solution Approach 2:
The system controls voltages to first and second subpixels based on desired gray levels and transmittance requirements. The voltage ratio control provides feedback mechanism to maintain both gray expression accuracy and transmittance stability
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 allows for precise gray expression in low gray regions while maintaining side visibility close to front visibility, preventing color display deviation and transmittance deterioration, thus enhancing overall display quality.
Implementation Method 1
The liquid crystal display generates an electric field in a liquid crystal layer by applying voltages to the field generating electrodes
Implementation Method 2
to determine orientations of liquid crystal molecules of the liquid crystal layer and to thereby control polarization of incident light
Implementation Method 3
VA mode liquid crystal displays are one in which the longitudinal axes of the liquid crystal molecules are arranged to be perpendicular to the upper and lower display panels when no electric field is applied
Data Source
AI summary
A liquid crystal display includes: a first pixel and a second pixel for displaying different colors, the first pixel and the second pixel each including a first sub-pixel electrode receiving a first voltage; a second sub-pixel electrode receiving a second voltage; an insulating layer disposed between the first sub-pixel electrode and the second sub-pixel electrode; and a common electrode receiving a common voltage. A first portion of the first sub-pixel electrode and a second portion of the second sub-pixel electrode overlap each other, a difference between the first voltage and the common voltage is larger than a difference between the second voltage and the common voltage, and a ratio of the second voltage to the first voltage for the first pixel is different from a ratio of the second voltage to the first voltage for the second pixel.