Quantum Dot Backlight Layout for Uniform White Display Color
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Solution Overview
Problem
Existing backlight systems using single-color LEDs and color conversion sheets often suffer from color unevenness when attempting to produce white light, due to variations in the proportions of blue and yellow light emission.
Innovation Solution
A backlight configuration featuring blue LEDs arranged in a matrix with a color conversion sheet containing red and green quantum dots, where blue quantum dots are strategically positioned to overlap with short-wavelength LEDs and the color conversion sheet has regions with a higher proportion of green quantum dots, particularly in a ring shape around the blue LEDs, to enhance light mixing and reduce color unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a color conversion sheet with red and green quantum dots is used to convert blue LED light into white light, then the structure remains relatively simple, but color unevenness occurs due to variations in the proportions of blue and yellow light emission
Solution Approach 1:
The patent applies local quality by creating regions with different quantum dot compositions within the color conversion sheet. Specifically, a first region contains red and green quantum dots, while a second region contains green and blue quantum dots. This spatial variation in material composition allows different portions of the backlight to emit light with adjusted color characteristics, thereby achieving uniform white light output across the entire display area while maintaining a relatively simple overall structure.
2Manufacturing precision
If blue quantum dots are arranged at positions overlapping short-wavelength LEDs and green quantum dots are concentrated in ring-shaped regions around blue LEDs, then light mixing is enhanced and color unevenness is reduced, but the device complexity increases
Solution Approach 1:
The patent implements local quality by defining specific spatial zones with tailored quantum dot compositions. The first region (overlapping short-wavelength LEDs) contains blue quantum dots to compensate for excessive blue light, while the second region (ring-shaped areas around blue LEDs) concentrates green quantum dots to enhance yellow light generation. This localized material differentiation optimizes light mixing and color uniformity without requiring complex additional components.
Solution Approach 2:
The patent applies parameter changes by varying the quantum dot composition and spatial distribution within the color conversion sheet. By adjusting the types and concentrations of quantum dots in different regions, the emission spectrum is locally modified to achieve uniform white light output. This approach changes the optical parameters (wavelength distribution, intensity ratios) across different zones to resolve color unevenness.
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 effectively minimizes color unevenness by ensuring consistent white light emission across the display area, maintaining a uniform color output without the need for complex structures or additional light sources.
Implementation Method 1
red quantum dots that emit red light in response to blue light and green quantum dots that emit green light in response to blue light are dispersed in the color conversion sheet
Implementation Method 2
blue quantum dots that emit blue light in response to the short-wavelength light are arranged in the color conversion sheet, at positions overlapping the short-wavelength LEDs in plan view
Data Source
AI summary
The present invention has been made to reduce a yellow shift around blue LEDs in a backlight including the blue LEDs and a color conversion sheet. Provided is a backlight including a light source including blue LEDs arranged in a matrix, on a plane, at first intervals, and a color conversion sheet arranged to cover the light source, in which red quantum dots that emit red light in response to blue light and green quantum dots that emit green light in response to blue light are dispersed in the color conversion sheet, short-wavelength LEDs that emit light of a shorter wavelength than that of blue light are arranged near the blue LEDs, and blue quantum dots that emit blue light in response to the short-wavelength light are arranged in the color conversion sheet, at positions overlapping the short-wavelength LEDs in plan view.