Backlight Unit Air Gap Prevents Green Light Absorption
Solution Overview
Problem
In liquid crystal display (LCD) devices, the overlap of red and green light emission areas leads to reduced luminance due to absorption of green light by red fluorescent materials, resulting in decreased light output.
Innovation Solution
A backlight unit with a color conversion layer that converts blue light into green light, combined with an optical sheet and an air gap between the color conversion layer and the optical sheet, ensures spatial separation of red and green light emission, preventing absorption and enhancing luminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If red fluorescent material is used to generate red light by absorbing blue light, then red light emission is achieved, but green light is absorbed in the overlap area, reducing luminance
Solution Approach 1:
The patent divides the backlight unit into separate emission regions: a red light emission area and a green light emission area. By spatially segmenting these regions and preventing their overlap, the harmful absorption of green light by red fluorescent material is eliminated while maintaining both red and green light emission capabilities.
2Illumination intensity
If green fluorescent material absorbs blue light to generate green light, then green light emission is achieved, but luminance is reduced due to overlap with red color absorption area
Solution Approach 1:
The patent segments the backlight unit into distinct green light emission areas that are spatially separated from red light emission areas. This segmentation prevents the overlap between green light emission and red color absorption, thereby preserving green light intensity and eliminating energy loss.
3Use of energy by moving object
If blue light is used as the primary light source, then white light can be generated through fluorescent materials, but green light is absorbed by red fluorescent material, reducing overall light output
Solution Approach 1:
The patent segments the backlight unit into separate red light emission areas and green light emission areas. This spatial segmentation allows blue light to be efficiently utilized in each region for generating the desired color without the harmful interaction of green light absorption by red fluorescent material, thereby increasing overall light output.
Solution Approach 2:
The patent applies local quality by using different fluorescent material configurations in different regions: red fluorescent material is used only in the red light emission area, and green fluorescent material is used only in the green light emission area. This localized optimization ensures that each material operates without interfering with the other, maximizing light output.
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 solution increases green light emission and luminance by preventing red light from absorbing green light, while also maintaining the light-condensing function of the optical sheet, resulting in improved display performance.
Implementation Method 1
a color conversion layer which is disposed on the light source and converts the first color light into a second color light
Implementation Method 2
an optical sheet which diffuses or condenses the second color light
Data Source
AI summary
The present disclosure is directed to a liquid crystal display device including a display panel having a red pixel, a green pixel, and a blue pixel; and a backlight unit which emits light to the display panel. The backlight unit includes a light source which outputs a first color light; a color conversion layer which is disposed on the light source and converts the first color light into a second color light; an optical sheet which diffuses or condenses the second color light; and an air gap formed between the color conversion layer and the optical sheet.