Backlight Unit Resin Layer Eliminates Light Guide Plate
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Solution Overview
Problem
Conventional liquid crystal display (LCD) backlight units are limited in thickness reduction due to the presence of a light guide plate, which degrades image quality, especially in large-area displays, and face issues with luminance variation and heat resistance.
Innovation Solution
A backlight unit is designed without a light guide plate, using a resin layer composed of oligomers, monomers, and additives, which diffuses and reflects light emitted by side-view LEDs, providing a thinner and more heat-resistant solution with improved optical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a light guide plate is used in the backlight unit, then light can be uniformly transferred to the LCD surface, but the thickness of the backlight unit increases and cannot be reduced further
Solution Approach 1:
The patent removes the light guide plate from the backlight unit structure and replaces it with a resin layer having specific refractive index characteristics. This extraction of the light guide plate directly reduces the overall thickness of the backlight unit while the resin layer maintains the light uniformity function through its optical properties
Solution Approach 2:
The patent changes the optical parameters of the resin layer, specifically setting the refractive index difference between the resin layer and air to be 0.05 or more. This parameter change enables the resin layer to effectively guide and uniformize light without requiring the traditional light guide plate structure
2Area of stationary object
If a light guide plate is used in large-area backlight units, then light coverage is achieved, but image quality is degraded
Solution Approach 1:
By removing the light guide plate from large-area backlight units and replacing it with the resin layer structure, the patent eliminates the image quality degradation issues associated with light guide plates while maintaining full area coverage through the optical characteristics of the resin layer
3Temperature
If conventional resin materials are used in the backlight unit, then ease of manufacture is achieved, but heat-resistant property and optical property are insufficient
Solution Approach 1:
The patent specifies particular refractive index parameters for the resin layer (difference of 0.05 or more from air) and uses UV-curable resin compositions. These parameter specifications ensure both heat resistance and optical performance while maintaining compatibility with standard UV curing manufacturing processes
Solution Approach 2:
The patent employs UV-curable resin compositions that combine specific refractive index characteristics with heat-resistant properties. These composite resin materials achieve both the required optical performance and thermal stability while remaining manufacturable through conventional UV curing techniques
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 resin layer effectively reduces luminance variation and enhances heat-resistant and optical properties, allowing for a thinner backlight unit with increased reliability and freedom in design, while maintaining even luminance and image quality.
Implementation Method 1
a resin layer which is laminated on the printed circuit board and forwardly induces diffusion of the emitted light
Implementation Method 2
light L entered to the light guide plate 30 is reflected upwardly from fine reflection patterns or a reflection sheet 40
Data Source
AI summary
Provided is a back light unit comprising a plurality of LED light source formed on a printed circuit board and a resin layer which is laminated on the LED light source and forwardly induces diffusion of the emitted light wherein the resin layer is made of synthetic resin comprising an oligomer. According to the present invention, an essential light guide plate for a general back light unit configuration is removed and a resin layer mainly consisting of an oligomer is used to guide the light source, and thereby decreasing the number of the light source, minimizing luminance variation when the unit is lighted at a high temperature and kept it for a predetermined time period, and implementing excellent heat-resistant property and optical property.