Display Substrate Blue Light Excitation Fluorescent Layers
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Solution Overview
Problem
Conventional TFT-LCD display technologies have low light-emitting efficiency due to complex structures and high backlight loss, particularly in converting white light from LED backlight sources into usable colors for display, with limited transmittance through color filter substrates.
Innovation Solution
A display substrate with pixel units comprising blue, red, green, and yellow subpixels, each with a transparent color filter layer and fluorescent powder layers that directly excite and emit respective colors under blue light illumination, eliminating the need for YAG fluorescent powders and simplifying the light-emitting process, thereby increasing luminescent efficiency and light utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional TFT-LCD structure with white light backlight source and color filter substrate is used, then full-color display is achieved, but light-emitting efficiency is low and backlight loss is high
Solution Approach 1:
The invention segments the color generation process by dividing the display into blue, red, green, and yellow subpixels, each with dedicated fluorescent powder layers. This allows selective excitation and emission of specific wavelengths, eliminating the need for broad-spectrum white light filtration and improving light-emitting efficiency while reducing backlight loss.
Solution Approach 2:
The invention changes the spectral parameters by using a blue light backlight source (wavelength 440±30nm) instead of white light, and employs fluorescent powders with specific emission wavelengths (red: 700±30nm, green: 530±30nm, yellow: 580±30nm). This parameter optimization enables direct excitation-emission matching, significantly improving light utilization efficiency.
2Illumination intensity
If YAG fluorescent powders are used in conventional LED backlight sources, then white light is generated, but additional filtration steps are required and light utilization is limited
Solution Approach 1:
The invention extracts and eliminates the YAG fluorescent powder layer from the backlight source, replacing it with a pure blue light LED. The color generation is then achieved through fluorescent powders integrated into the display substrate itself, removing the need for additional filtration steps and simplifying the overall structure while maintaining brightness.
Solution Approach 2:
The invention introduces fluorescent powder layers as intermediaries between the blue light source and the final displayed colors. These fluorescent layers convert the blue light into specific colors (red, green, yellow) through photoluminescence, eliminating the need for complex filtration while achieving full-color display.
3Manufacturing precision
If transparent color filter layers are added in red, green, and yellow subpixels, then color purity is improved, but structural complexity increases
Solution Approach 1:
The invention merges the color filter function with the fluorescent powder layers by integrating transparent color filter layers within the same subpixel structures. This combination achieves color purity enhancement while maintaining a unified and relatively simple overall structure, avoiding the need for separate filtering components.
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 significantly enhances light-emitting efficiency and utilization rates, particularly for blue and yellow subpixels, allowing for higher brightness and improved color gamut display without additional filtration steps, optimizing the backlight usage and image quality.
Implementation Method 1
a red fluorescent powder layer arranged in the red subpixel and configured to emit a red light beam under the excitation of the blue light beam; a green fluorescent powder layer arranged in the green subpixel and configured to emit a green light beam under the excitation of the blue light beam; a yellow fluorescent powder layer arranged in the yellow subpixel and configured to emit a yellow light beam under the excitation of the blue light beam
Data Source
AI summary
The present disclosure provides a display substrate and a display device. Each pixel unit includes: a blue sub-pixel, a transparent color filter layer being arranged in the blue subpixel and configured to allow a blue light beam to be transmitted therethrough toward the display substrate; a red subpixel, a red fluorescent powder layer being arranged in the red subpixel and configured to emit a red light beam under the excitation of the blue light beam; a green subpixel, a green fluorescent powder layer being arranged in the green subpixel and configured to emit a green light beam under the excitation of the blue light beam; and a yellow subpixel, a yellow fluorescent powder layer being arranged in the yellow subpixel and configured to emit a yellow light beam under the excitation of the blue light beam.