Liquid Crystal Display Driving Voltage Control for Color Shift
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Solution Overview
Problem
Negative-type VA liquid crystal displays experience color shift when viewed at large angles, and existing solutions to mitigate this issue, such as dividing pixels into sub-pixels, compromise the aperture ratio and increase backlight module costs.
Innovation Solution
A liquid crystal display that provides different pixel voltages of the same polarity to each liquid crystal pixel in two adjacent frames, with the pixel voltage changing based on an average pixel voltage parameter, to deflect liquid crystal molecules and maintain aperture ratio without adding metal wires or thin-film transistors, while ensuring equal luminance products in both frames.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If pixels are divided into Main/Sub secondary pixels to reduce color shift, then color shift is improved, but aperture ratio is reduced and transmittance decreases
Solution Approach 1:
The patent applies parameter changes by providing different pixel voltages to Main and Sub secondary pixels. Specifically, the Sub secondary pixel is provided with a voltage different from the Main secondary pixel (e.g., Main pixel voltage = 5V, Sub pixel voltage = 3V). This voltage differentiation changes the optical parameters of the liquid crystal molecules in Sub pixels, enabling them to compensate for color shift at large viewing angles without requiring additional structural elements that would reduce aperture ratio.
2Object-affected harmful factors
If pixels are divided into Main/Sub secondary pixels to reduce color shift, then color shift is improved, but device complexity increases due to additional metal wires and TFTs
Solution Approach 1:
The patent applies universality by making the existing liquid crystal pixel structure perform multiple functions. The Sub secondary pixel, which is already part of the standard pixel array, is given an additional function of color shift compensation through differentiated voltage application. This eliminates the need for separate compensation structures, metal wires, or TFTs, as the existing pixel infrastructure is made multi-functional by simply changing the voltage parameters applied to different pixel regions.
3Illumination intensity
If backlight module luminance is increased to maintain transmittance, then transmittance is improved, but cost increases
Solution Approach 1:
The patent applies mechanics substitution by replacing the mechanical/optical approach of increasing backlight luminance with an electrical control approach. Instead of physically increasing the backlight module's light output (which would require more powerful LEDs or higher power consumption), the patent uses electrical voltage differentiation to control the liquid crystal molecules' optical properties. This substitutes a purely optical solution with an electro-optical control mechanism, reducing the burden on the backlight module and thereby reducing cost.
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 prevents color shift at large viewing angles without reducing the aperture ratio and eliminates flicker by maintaining consistent luminance across frames, doubling the frame refresh frequency and equalizing luminance in adjacent frames.
Implementation Method 1
the driving module is configured to respectively provide different pixel voltages of the same polarity for each of the liquid crystal pixels in two adjacent frames, so as to deflect liquid crystal molecules of each of the liquid crystal pixels
Data Source
AI summary
A liquid crystal display and a method for driving same, capable of eliminating large viewing angle color shift of a liquid crystal display having VA liquid crystals. The liquid crystal display includes a liquid crystal panel and a driving module. The liquid crystal panel includes a plurality of liquid crystal pixels (Pab, wherein 1≤a≤A, 1≤b≤B, and both a and b are integers) arranged in an array. The liquid crystal display is configured to display a same picture in two adjacent frames. The driving module is used for respectively providing different pixel voltages of the same polarity to each liquid crystal pixel (Pab) in the two adjacent frames to deflect liquid crystal molecules of the liquid crystal pixel (Pab).