Liquid Crystal Display with Segmented Scanning and Temporal Light Control
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Solution Overview
Problem
Liquid crystal displays (LCDs) face color accuracy issues due to color mixing phenomena in temporal division processes, where the limited time to charge liquid crystal capacitors results in mixed colors from adjacent frames.
Innovation Solution
The LCD pixels are divided into regions for scanning, with a light source controller managing multiple light sources to turn off adjacent field light sources during different frames, allowing for selective application of data signals and light supply during specific fields, using a frame memory to separate image signals by primary colors and applying monochromatic light during secondary fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If temporal division process is used to present colors sequentially, then color presentation capability is improved, but color accuracy deteriorates due to color mixing from adjacent frames
Solution Approach 1:
The display panel is divided into multiple scanning regions that are scanned sequentially within each frame. This segmentation allows the system to process and display different color fields (red, green, blue) for different spatial regions at different times, preventing color mixing between adjacent frames while maintaining temporal color presentation capability.
Solution Approach 2:
The frame memory stores and separates image signals for each primary color (red, green, blue) in advance before display. This preliminary separation and storage of color signals enables the system to accurately retrieve and display the correct color data for each scanning region without interference from adjacent frame data, thus maintaining color accuracy.
2Productivity
If data signals are applied to all pixels in each field, then productivity is improved, but charging time per pixel deteriorates resulting in less light passing through
Solution Approach 1:
The frame memory and data signal application process is segmented into multiple fields corresponding to different primary colors (red, green, blue). Each field processes only the relevant color data for the current scanning region, allowing sufficient charging time for the liquid crystal capacitors while maintaining overall productivity through sequential processing of all color fields across all regions.
3Illumination intensity
If light sources are turned on for all fields, then illumination intensity is improved, but color mixing from adjacent frames worsens
Solution Approach 1:
Different light sources (red, green, blue LEDs) are selectively activated based on the specific scanning region and color field being displayed. Instead of having all light sources on continuously, the system activates only the appropriate light source for the current region and color, providing sufficient local illumination intensity while preventing color mixing from adjacent frames.
Solution Approach 2:
The light sources operate in periodic cycles corresponding to the sequential scanning of different color fields (red, green, blue) across different scanning regions. Each light source is activated only during its corresponding color field period, maintaining illumination intensity when needed while preventing color mixing between different color fields and frames.
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 mixing, enhances color reproducibility, and improves image quality by increasing the charging time of liquid crystal capacitors and overlapping lighting times, resulting in better resolution and image clarity.
Implementation Method 1
a liquid crystal layer exhibiting dielectric anisotropy located between them
Implementation Method 2
separate sources of the primary colors are provided by light emitting diodes (LEDs)
Data Source
AI summary
The present invention relates to a liquid crystal display. The liquid crystal display includes a liquid crystal panel assembly having a plurality of scanning regions that include a plurality of pixels, respectively; a plurality of light source units that include a plurality of light sources supplying light to the plurality of scanning regions, respectively; a data driver that selects gray voltages corresponding to image signals and applies the selected gray voltages to the plurality of pixels as data signals, respectively; and a light source controller that controls the turning on and off of the light sources. One frame is divided into red, green, blue, and black fields, and the light source controller turns off the light source during the black field. Accordingly, the color mixing phenomenon is reduced, and the lighting time of the light source and the charging time of the pixels increase, thereby improving the image quality.