Grooved Light-Guiding Plate for Uniform LCD Backlight
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Solution Overview
Problem
Existing edge type backlight units for large-sized LCD devices face challenges in achieving uniform brightness and high brightness, while also being thick and costly due to the need for expensive components like DBEF sheets.
Innovation Solution
A backlight unit with a light-guiding plate featuring grooves to house multiple light-emitting lamps, combined with a light-diffusion sheet and reflective sheet, which enhances light distribution and reduces the need for expensive components by providing uniform brightness and high contrast ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If edge type backlight unit is used for large-sized LCD device, then light uniformity is improved, but brightness is insufficient and thickness increases
Solution Approach 1:
The backlight unit is segmented into multiple independent lamp units arranged in parallel, with each lamp unit containing a lamp, lamp holder, and reflective sheet. This segmentation allows each lamp to independently illuminate its corresponding region, achieving high brightness across the entire large display area while maintaining thin profile through optimized individual component arrangement.
Solution Approach 2:
The patent transitions from a single-edge light source arrangement to a multi-dimensional array of lamp units distributed across the display area. By arranging multiple lamp units in parallel and stacking components vertically with precise spacing, the system achieves high brightness without increasing overall thickness, as the light-emitting elements are distributed across multiple dimensions rather than concentrated at a single edge.
2Illumination intensity
If multiple lamps are provided on light-diffusion sheet, then brightness is improved, but thickness increases
Solution Approach 1:
The lamp units are nested within the light-guiding plate structure, with lamps positioned in grooves formed in the light-guiding plate. The reflective sheets are nested within lamp holders, and the entire assembly is integrated into the backlight unit's layered structure. This nesting approach allows multiple lamps to be accommodated without proportionally increasing thickness, as components share space efficiently.
Solution Approach 2:
Each lamp unit is designed with localized reflective sheets positioned immediately behind each lamp, creating localized high-brightness regions. The reflective sheets are specifically positioned to reflect light toward the light-diffusion sheet only where needed, achieving high brightness in each region without requiring increased thickness across the entire structure.
3Illumination intensity
If expensive components like DBEF sheets are used, then uniformity is improved, but fabrication cost increases
Solution Approach 1:
The patent replaces expensive DBEF sheets with standard reflective sheets and light-diffusion sheets that are more economical and easier to manufacture. The reflective sheets are simple metallic or coated surfaces that can be produced at lower cost, while the light-diffusion sheets are standard optical materials. This substitution maintains adequate uniformity without the high fabrication costs associated with expensive specialized components.
Solution Approach 2:
The patent achieves uniformity by changing the arrangement and positioning parameters of multiple lamp units and reflective sheets, rather than relying on expensive specialized materials. By optimizing the spacing, orientation, and positioning of these standard components, the system achieves the desired uniform light distribution at lower fabrication cost than using expensive DBEF sheets.
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 achieves improved uniformity and high brightness for large-sized LCD devices, reduces thickness, and lowers fabrication costs by eliminating the need for expensive DBEF sheets, while maintaining high contrast ratios.
Implementation Method 1
a light-guiding plate which guides light emitted from the lamps
Implementation Method 2
a light-diffusion sheet which diffuses the light guided by the light-guiding plate
Implementation Method 3
a reflective sheet which reflects light emitted from the lamps to the light-guiding plate
Data Source
AI summary
A backlight unit and a display device using the same include a light-guiding plate having a plurality of grooves, a plurality of light-emitting lamps in the respective grooves of the light-guiding plate, and a light-diffusion sheet above the light-guiding plate and the lamps.