Backlight Color Conversion Sheet Layout for LED Yellow Shift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices using single-color LEDs and color conversion sheets for backlighting often experience uneven color distribution due to variations in the ratio of blue to yellow light, leading to color irregularities, particularly in methods involving quantum dot boxes for each LED, which have a complex structure.
Innovation Solution
A display device design featuring a color conversion sheet with a ring-shaped area devoid of color conversion material surrounding each LED, or with varying QD density, to control light conversion and minimize color irregularities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a color conversion sheet with uniform color conversion material is used, then the structure is simple, but color irregularities occur due to uneven blue to yellow light ratio
Solution Approach 1:
The patent applies local quality by creating a non-uniform distribution of color conversion material within the color conversion sheet. Specifically, the concentration of color conversion particles varies across different regions of the sheet, with higher concentration in certain areas and lower concentration in others. This localized variation in material properties enables different regions to convert blue light to yellow light at different rates, compensating for the non-uniform light emission characteristics of individual LEDs and achieving overall color uniformity across the display panel.
2Manufacturing precision
If quantum dot boxes are arranged for each LED to achieve uniform white light, then color uniformity is improved, but the structure becomes complex
Solution Approach 1:
The patent merges the functions of multiple individual quantum dot boxes into a single integrated color conversion sheet. Instead of having separate quantum dot boxes for each LED, the invention combines all color conversion materials into one continuous sheet with spatially varying concentration. This merging approach maintains the color uniformity function while dramatically simplifying the overall structure, reducing the number of components, and eliminating the need for precise alignment of multiple discrete elements.
3Ease of manufacture
If color conversion material is uniformly distributed, then manufacturing is easy, but blue to yellow light ratio varies causing color irregularities
Solution Approach 1:
The patent applies parameter changes by modifying the concentration parameter of the color conversion material throughout the color conversion sheet. Rather than maintaining a constant concentration, the invention varies the concentration parameter spatially, creating regions with different material densities. This parameter variation enables precise control over the blue to yellow light conversion ratio in different areas, achieving color consistency while remaining compatible with conventional manufacturing techniques for creating gradient or patterned material distributions.
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
The proposed design achieves a more uniform white backlight with reduced color irregularities using a simpler structure by optimizing the distribution of color conversion material, enhancing manufacturing ease and stability.
Implementation Method 1
a color conversion sheet that converts blue to yellow is placed in the direction of the output of a blue LED, white light produced by mixing blue with yellow is emitted from the color conversion sheet
Data Source
AI summary
The objective is to reduce yellow shift around a blue LED in a backlight using the blue LED and a color conversion sheet. To solve this problem, one of the structures of invention is: a display device including a display panel and a backlight, the backlight having a plurality of LEDs arranged on a substrate and a color conversion sheet arranged between the plurality of LEDs and the display panel, the color conversion sheet being formed of color conversion material and a binder, the color conversion sheet having a ring-shaped area without the color conversion material, the ring-shaped area surrounding each of the plurality of LEDs in a plan view.