Backlight Unit Alternating Light Guide Sections
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In liquid crystal display (LCD) devices, the lamp mura phenomenon occurs due to inadequate overlap of light from LEDs, leading to non-uniform brightness and reduced display quality, which is exacerbated by the need for closer LED spacing to achieve large and thin designs, increasing costs and power consumption.
Innovation Solution
A backlight unit design featuring alternating sections on light guide plates with patterns and reflection sheets, where LEDs are arranged in lines facing opposite sides of the plates, providing a uniform plane light source by scattering and refracting light to prevent hot spots and darkness areas, and allowing for easier manufacturing with reduced power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the distance between LEDs is reduced to achieve large and thin LCD designs, then the display area and thinness are improved, but the lamp mura phenomenon occurs due to inadequate light overlap, causing non-uniform brightness
Solution Approach 1:
The light guide plate is divided into multiple sections with different optical characteristics. Specifically, the plate includes first sections with light scattering particles and second sections without such particles, creating alternating regions that collectively provide uniform light distribution even when LEDs are spaced closely together.
Solution Approach 2:
Different regions of the light guide plate are given different optical properties. The first sections contain light scattering particles to diffuse light and eliminate hot spots, while the second sections maintain higher light transmission efficiency. This local differentiation allows the system to achieve uniform brightness without requiring large LED spacing.
2Volume of moving object
If the distance between LEDs is reduced to decrease device size, then the compactness is improved, but the number of LEDs must be increased to maintain light coverage, increasing cost and power consumption
Solution Approach 1:
The light guide plate is segmented into regions with different optical densities. The first sections with light scattering particles efficiently diffuse light from LEDs, while the second sections allow direct light transmission. This segmentation enables effective light utilization with fewer LEDs, reducing power consumption while maintaining compact device size.
3Volume of moving object
If LEDs are arranged closely to achieve thin design, then the thickness is reduced, but hot spots and darkness areas appear, lowering display quality
Solution Approach 1:
The light guide plate incorporates first sections with light scattering particles positioned at specific locations where hot spots would occur, and second sections without particles where direct light transmission is sufficient. This localized optical modification ensures uniform light distribution across the entire plate even when LEDs are spaced closely together, maintaining high display quality in a thin form factor.
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 design provides a uniform plane light source for large-sized LCDs, preventing the lamp mura phenomenon, ensuring uniform brightness and improved image quality while reducing power consumption and manufacturing complexity.
Implementation Method 1
providing a uniform plane light source by scattering and refracting light
Implementation Method 2
providing a uniform plane light source by scattering and refracting light
Implementation Method 3
a reflection plate, first and second light guide plates over the reflection plate
Data Source
AI summary
A backlight unit for a liquid crystal display device includes a reflection plate, first and second light guide plates over the reflection plate, the second light guide plate disposed between the first light guide plate and the reflection plate, wherein the first light guide plate includes first and second sections alternating with each other, and the second light guide plate includes third and fourth sections alternating with each other, the first and third sections having patterns at rear surfaces, the second and fourth sections excluding patterns, wherein the first section corresponds to the fourth section, and the second section corresponds to the third section, first and second light-emitting diode (LED) assemblies at opposite sides of the first and second light guide plates, each of the first and second LED assemblies including LEDs arranged in first and second lines, and a plurality of optical sheets over the first light guide plate, wherein the LEDs of the first lines of the first and second LED assemblies face opposite side surfaces of the first light guide plate, and the LEDs of the second lines of the first and second LED assemblies face opposite side surfaces of the second light guide plate.