LED Backlight Unit Cover Frame Design for Luminance and Power
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Solution Overview
Problem
Conventional backlight units for LCDs, particularly those using Cold Cathode Fluorescent Lamps (CCFLs), face issues with high power consumption, low color reproduction efficiency, and environmental pollution due to mercury usage, necessitating a more efficient and environmentally friendly solution.
Innovation Solution
A backlight unit design incorporating a lightweight and mass-producible cover frame with a light source module, reflectors, and an optical member to create an air guide, utilizing Light Emitting Diodes (LEDs) for improved power efficiency and color reproduction, and featuring a simplified configuration for enhanced reliability and economic efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If CCFLs are used as light sources in backlight units, then sufficient luminance can be achieved, but power consumption increases and color reproduction efficiency decreases to about 70% of CRT
Solution Approach 1:
The patent transitions from CCFL light sources to LED light sources, fundamentally changing the illumination parameter. LEDs consume significantly less power while maintaining or improving luminance output, directly resolving the contradiction between sufficient luminance and high power consumption.
Solution Approach 2:
The patent replaces the gas discharge mechanism of CCFLs with the electroluminescence mechanism of LEDs. This substitution eliminates the need for high voltage ignition and continuous power application required by CCFLs, thereby reducing power consumption while maintaining luminance.
2Illumination intensity
If CCFLs are used as light sources, then luminance can be maintained, but color reproduction efficiency is limited to about 70% of CRT
Solution Approach 1:
The patent changes the spectral characteristics parameter by using LEDs with different color temperatures and phosphor combinations. This enables color reproduction exceeding 100% of the NTSC standard, directly improving color reproduction efficiency while maintaining luminance.
Solution Approach 2:
The patent employs composite phosphor materials in the LED design to achieve broader spectral coverage. By combining multiple phosphors with LEDs, the system achieves superior color reproduction compared to single-phosphor CCFL designs.
3Illumination intensity
If CCFLs are used in backlight units, then sufficient light output is achieved, but environmental pollution occurs due to mercury usage
Solution Approach 1:
The patent replaces the mercury-based gas discharge system of CCFLs with a solid-state LED system. This substitution completely eliminates mercury usage while maintaining light output, directly resolving the environmental pollution issue.
Solution Approach 2:
The patent adopts LEDs which are free from toxic materials like mercury, making them environmentally friendly and safer for disposal compared to CCFLs containing hazardous substances.
4Stability of the object's composition
If a complex cover frame structure is used to support the air guide, then structural stability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent integrates the cover frame structure with the air guide components, merging multiple functions into a single integrated structure. This reduces the number of separate parts and assembly steps while maintaining structural stability, thereby simplifying manufacturing.
Solution Approach 2:
The cover frame is designed to perform multiple functions simultaneously: structural support, air guide formation, and component mounting. This multi-functionality reduces the need for additional specialized components, simplifying the overall manufacturing process.
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 LED-based backlight unit achieves significant power savings, exceeds color reproduction capabilities of traditional systems, and reduces environmental impact, while maintaining uniform luminance and a lightweight, mass-producible design.
Implementation Method 1
first and second reflectors, at least one light source module disposed between the first reflector and the second reflector
Implementation Method 2
an optical member disposed at a predetermined distance from the second reflector to define a space between the optical member and the second reflector
Data Source
AI summary
Disclosed are a backlight unit and a display apparatus using the same. The backlight unit includes first and second reflectors, a light source module, an optical member spaced apart from the second reflector, a first cover to come into contact with the second reflector and optical member, a second cover coupled to the first cover to support the light source module, and a third cover coupled to the first and second covers. The first cover includes a bottom plate, first lateral plates facing each other with respect to a first direction, second lateral plates facing each other in a second direction, a first coupling portion disposed at each first lateral plate and coupled to the second cover, a second coupling portion disposed at each second lateral plate and coupled to the optical member, and a third coupling portion disposed at each second lateral plate and coupled to the third cover.