Backlight Reflecting Sheets for Uniform Luminance
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Solution Overview
Problem
Liquid crystal display devices using light emitting diodes (LEDs) suffer from non-uniform luminance due to variations in light distribution, leading to hot spots near the light source and dark regions farther away, which affects image quality and manufacturing costs.
Innovation Solution
A backlight assembly with reflecting sheets of different surface roughness and strategically positioned holes, combined with lenses to direct light uniformly across the display panel, ensuring consistent luminance and reducing the number of light sources and lenses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If light sources are positioned below the liquid crystal display panel in a direct type display, then the light source can be efficiently integrated into the display structure, but non-uniform luminance occurs with hot spots near the light source and dark regions farther away
Solution Approach 1:
The patent applies local quality by using reflecting sheets with different surface roughness at different locations. The first reflecting sheet has a first surface roughness and the second reflecting sheet has a second surface roughness different from the first, allowing each region to optimize light reflection according to its distance from the light source, thereby achieving uniform luminance across the display panel
Solution Approach 2:
The patent changes the surface roughness parameter of the reflecting sheets to control light reflection characteristics. By adjusting the surface roughness of different reflecting sheets, the light distribution is optimized to eliminate hot spots and dark regions while maintaining efficient light source integration
2Ease of manufacture
If reflecting sheets with uniform surface roughness are used, then the manufacturing process is simplified, but luminance uniformity across the display panel deteriorates
Solution Approach 1:
The patent implements local quality by specifying that the first reflecting sheet and the second reflecting sheet have different surface roughness values. This local differentiation allows each reflecting sheet to be optimized for its specific position relative to the light source, improving luminance uniformity while maintaining manufacturing feasibility through standardized production of each sheet type
3Illumination intensity
If multiple light sources are used to improve luminance uniformity, then hot spots and dark regions are reduced, but manufacturing cost and device complexity increase
Solution Approach 1:
The patent changes the surface roughness parameter of existing reflecting sheets rather than adding more light sources or lenses. This parameter modification optimizes the light distribution from the existing light sources, achieving uniform luminance without increasing device complexity or manufacturing cost
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 uniform luminance across the liquid crystal display device, reducing manufacturing costs and improving image quality by optimizing light distribution and reducing hot spots and dark regions.
Implementation Method 1
reflecting sheets having a first surface roughness and a second surface roughness that are different from each other
Data Source
AI summary
Disclosed herein are a backlight assembly and a liquid crystal display device including the same, which is capable of producing more uniform luminance. The liquid crystal display device includes: a backlight assembly, and a liquid crystal display panel positioned above the backlight assembly. The backlight assembly includes: reflecting sheets having a first surface roughness and a second surface roughness that are different from each other; and light source disposed adjacent to the reflecting sheets.