Grid Backlight Unit Resolves Hot Spot and Light Leakage
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Solution Overview
Problem
Display devices with narrow bezels face issues of hot spot defects due to close proximity of light sources to the light guide film, leading to brightness differences, and thinner light guide films result in light leakage defects, deteriorating the display quality.
Innovation Solution
A backlight unit with a light emitting array comprising micro-scale light sources arranged in multiple rows on a printed circuit board, a light guide film, a color conversion layer, and an optical member, where the light sources are spaced apart to minimize hot spot and light leakage defects, and the color conversion layer converts light to specific colors using quantum dots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the distance between light sources and light guide film is reduced to achieve slimming, then the thickness of the display device is reduced, but hot spot defects occur due to brightness differences
Solution Approach 1:
The light guide film is divided into multiple sections with different thicknesses (first light guide film portion and second light guide film portion). The first portion has a greater thickness than the second portion, allowing the light guide film to be thinner overall while maintaining sufficient thickness in critical areas to prevent hot spot defects and ensure uniform light distribution.
2Length of moving object
If the thickness of light guide film is reduced to achieve slimming, then the overall size is reduced, but light leakage defects occur
Solution Approach 1:
Different portions of the light guide film have different thicknesses tailored to their specific functional requirements. The first light guide film portion maintains greater thickness to prevent light leakage and ensure uniform light distribution, while the second light guide film portion can be thinner to achieve overall slimming. This local differentiation allows the device to be thin without sacrificing display quality.
3Device complexity
If light sources are arranged in a single row, then the structure is simple, but hot spot defects occur due to large brightness differences between bright zones and dark zones
Solution Approach 1:
The light sources are arranged in a two-dimensional grid pattern across multiple rows and columns rather than a single row. This dimensional expansion allows for more uniform distribution of light sources across the light guide film surface, reducing the brightness difference between adjacent regions and eliminating hot spot defects while maintaining reasonable structural complexity.
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 light output efficiency, reduces hot spot and light leakage defects, and enables slim display designs while maintaining image quality by ensuring uniform light distribution and minimizing defects.
Implementation Method 1
a color conversion layer configured to convert light that has passed through the light guide film into light of a specific color
Data Source
AI summary
A backlight unit is described. The unit includes a light emitting array having a plurality of light sources configured to emit light, and a printed circuit board on which the light sources are arranged; a light guide film configured to guide light emitted from the light sources in one direction; a color conversion layer configured to convert light that has passed through the light guide film into light of a specific color; and an optical member disposed on the color conversion layer. The light sources include first light sources arranged on a first row of the printed circuit board, and second light sources arranged on a second row of the printed circuit board. The first light sources are spaced apart from each other by a predetermined distance, and the second light sources are spaced apart from each other by the predetermined distance.