Backlight Unit Light Path Converters Prevent Halo
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Solution Overview
Problem
Display devices face challenges in reducing thickness while maintaining image quality and preventing the halo phenomenon in local dimming methods, which can lead to deteriorated contrast ratios and increased power consumption.
Innovation Solution
A backlight unit design featuring a printed circuit with light sources, a first base film with specific hole patterns, light source protectors, and light path converters made of different materials, which helps in directing light efficiently and minimizing light diffusion between emitting areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the thickness of the backlight unit is reduced to reduce the thickness of the display device, then the thickness of the display device is reduced, but an optical gap between the light source and the display panel may not be sufficiently secured, so that image quality can be deteriorated
Solution Approach 1:
The base film is segmented into multiple functional regions: light source holder regions that position light sources, light blocking regions that prevent light leakage, and light guiding regions that direct light toward the display panel. This segmentation allows each region to perform its specific function optimally, enabling thin design while maintaining image quality through precise light control
Solution Approach 2:
The base film acts as an intermediary component between the light sources and the display panel. It mediates light propagation by containing light guiding regions with refractive indices different from surrounding materials, thereby controlling light paths and ensuring sufficient optical gap functionality even in thin configurations
2Illumination intensity
If the amount of light provided to the display panel increases to improve luminance, then the luminance of the display panel can be improved, but high power consumption can be needed
Solution Approach 1:
The patent replaces direct increases in light source power with optical structure optimization. By designing light guiding regions with specific refractive indices and geometries, the system efficiently directs and concentrates light toward the display panel, achieving high luminance through optical mechanics rather than increased electrical power input
Solution Approach 2:
The patent changes optical parameters such as refractive index of the light guiding regions and geometric parameters of the base film structure to optimize light extraction and direction. These parameter optimizations enable more efficient light utilization, improving luminance without proportionally increasing power consumption
3Manufacturing precision
If the backlight unit is driven by a local dimming method to improve contrast, then the contrast ratio can be improved, but a halo phenomenon can occur in which light emitted from one light emitting area spreads to other adjacent light emitting areas that are not driven
Solution Approach 1:
The patent extracts and removes harmful light propagation paths by introducing light blocking regions within the base film. These regions actively prevent light from spreading between adjacent light emitting areas, eliminating the halo phenomenon while preserving local dimming contrast benefits
Solution Approach 2:
The base film structure provides different local properties: light guiding regions with specific refractive indices for light emission areas, and light blocking regions for boundary areas. This local differentiation ensures that each region performs its specific function - guiding light where needed and blocking it where unnecessary - thereby preventing halo effects while maintaining contrast
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 enhances image quality by improving light emission directionality, reduces power consumption, and prevents the halo phenomenon, resulting in improved contrast ratios and luminance uniformity.
Implementation Method 1
a plurality of light path converters disposed on the printed circuit, disposed in the plurality of second holes and including a material different from that of the plurality of light source protectors
Implementation Method 2
light path converters disposed on the printed circuit, disposed in the plurality of second holes
Implementation Method 3
a plurality of light sources disposed on the printed circuit
Implementation Method 4
light sources disposed on the printed circuit
Data Source
AI summary
A backlight unit and a display device including the backlight unit are discussed. The backlight unit can include a printed circuit, a plurality of light sources disposed on the printed circuit, and a first base film disposed on the printed circuit and including a plurality of first holes provided in an area where the plurality of light sources are disposed and a plurality of second holes spaced apart from the plurality of first holes, wherein the plurality of second holes surround the plurality of first holes. The backlight unit can further include a plurality of light source protectors disposed on the printed circuit and disposed in the plurality of first holes, a plurality of light path converters disposed on the printed circuit and including a material different from the light source protectors, and a light control film disposed on the light source protectors and the light path converters.