Backlight Unit Light Guide Plate Segmentation for Thermal Expansion
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Solution Overview
Problem
The existing backlight units for liquid crystal display devices suffer from luminance variations due to thermal expansion differences between the light guide plate and the reflector, leading to wrinkles and defects in the display screen.
Innovation Solution
A backlight unit design featuring a light guide plate with a first set of geometric shapes to direct light uniformly and a second set of geometric shapes at the peripheral portion to prevent sticking to the reflector, with the second set having a lower density and larger size to manage static electricity and thermal expansion issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the light guide plate and reflector are placed adjacent to each other to form the backlight unit, then the device structure is compact and functional, but static electricity causes the light guide plate to stick tightly to the reflector
Solution Approach 1:
The bottom surface of the light guide plate is divided into multiple regions with different geometric shape patterns. The first region has a first pattern of geometric shapes while the second region has a second pattern, creating segmented functional zones that address different problems (light direction vs. sticking prevention) in different areas.
Solution Approach 2:
Different regions of the light guide plate bottom surface are given different local properties through distinct geometric shape patterns. The first region optimizes for light guidance while the second region optimizes for preventing static electricity sticking, allowing each area to have the specific quality needed for its function.
2Device complexity
If the light guide plate and reflector are placed adjacent to each other, then the device structure is compact, but thermal expansion differences cause the reflector to wrinkle and produce luminance variations
Solution Approach 1:
The bottom surface of the light guide plate is divided into multiple regions with different geometric shape patterns. The first region has a first pattern of geometric shapes while the second region has a second pattern, creating segmented functional zones that address different problems (light direction vs. sticking prevention) in different areas.
Solution Approach 2:
Different regions of the light guide plate bottom surface are given different local properties through distinct geometric shape patterns. The first region optimizes for light guidance while the second region optimizes for preventing static electricity sticking, allowing each area to have the specific quality needed for its function.
3Manufacturing precision
If geometric shapes are added to the light guide plate to prevent sticking and control thermal expansion, then display quality is improved, but the device structure becomes more complex
Solution Approach 1:
The geometric shape patterns are integrated directly into the light guide plate structure during manufacturing, merging the sticking prevention function and light guidance function into a single component rather than requiring separate elements. This reduces overall device complexity while achieving the desired luminance uniformity.
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 ensures uniform luminance across the LCD device, preventing luminance differences and improving display quality by preventing the light guide plate from sticking to the reflector, even under heat expansion, thus maintaining consistent display performance.
Implementation Method 1
a light guide that guides light from the lamp toward the optical sheets
Implementation Method 2
a first plurality of geometric shapes at the rear surface thereof that substantially directs the light incident on the light guide toward the optical sheets
Implementation Method 3
a second plurality of geometric shapes at a peripheral portion of the rear surface thereof to prevent the reflector from sticking to the light guide
Implementation Method 4
The backlight unit produces heat during operation, and the heat expands the light guide plate 30 and the reflector 22
Data Source
AI summary
A backlight unit for a liquid crystal display panel includes a lamp, a plurality of optical sheets, a light guide that guides light from the lamp toward the optical sheets, and a reflector facing a rear surface of the light guide. The light guide includes a first plurality of geometric shapes at the rear surface thereof that substantially directs the light incident on the light guide toward the optical sheets, and a second plurality of geometric shapes at a peripheral portion of the rear surface thereof to prevent the reflector from sticking to the light guide, a density of the second plurality of geometric shapes is less than the density of the first plurality of geometric shapes.