Backlight Unit Reflecting Surfaces with Varying Inclination Angles
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Solution Overview
Problem
In direct-type backlight units, the non-uniform arrangement of light sources leads to variations in light reflection, resulting in uneven light distribution and optical characteristics, which can cause display irregularities in liquid crystal displays.
Innovation Solution
The implementation of reflecting surfaces with varying inclination angles, where light sources closer to the edge have a larger inclination angle and those farther away have a smaller inclination angle, ensuring uniform light distribution across the radiation area by effectively reflecting light to the edges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If light sources are arranged in a line on the lower plate, then the assembly process is simplified, but the arrangement precision deteriorates making it difficult to accurately position light sources equidistant from side walls
Solution Approach 1:
The side walls are divided into multiple segments with different inclination angles (first inclination angle and second inclination angle) instead of being uniform. This segmentation allows each segment to serve a specific function in compensating for light source position variations, resolving the contradiction between simplified assembly and precise positioning.
Solution Approach 2:
Different portions of the side walls are assigned different local properties (different inclination angles) based on their position and function. The first side walls have a first inclination angle while the second side walls have a second inclination angle, creating local quality variations that compensate for non-uniform light source arrangement.
2Manufacturing precision
If the distance between light source and side wall is large, then the assembly tolerance is easier to achieve, but the amount of light reflected from the side wall is reduced
Solution Approach 1:
The inclination angle parameter of the side walls is changed to compensate for the increased distance between light sources and side walls. By adjusting the inclination angle, the reflection path is modified to maintain adequate light intensity in the radiation area even when light sources are positioned farther from the side walls.
3Illumination intensity
If the distance between light source and side wall is small, then the amount of light reflected is increased, but the arrangement precision becomes more difficult to achieve
Solution Approach 1:
The side walls are segmented into different sections with different inclination angles. This segmentation allows the system to achieve high light reflection efficiency without requiring extremely precise light source positioning, as the varying angles compensate for position variations.
4Device complexity
If uniform inclination angles are used for all side walls, then the structure is simplified, but the light distribution uniformity deteriorates
Solution Approach 1:
Different sections of the side walls are assigned different local properties (different inclination angles) to optimize light distribution. The first and second side walls have different inclination angles that are specifically designed to compensate for variations in light source arrangement, achieving uniform light distribution across the radiation area.
Solution Approach 2:
The side walls are designed with asymmetric inclination angles rather than uniform symmetric angles. This asymmetry is intentionally introduced to compensate for the non-uniform arrangement of light sources, achieving overall uniform light distribution in the radiation area.
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 configuration ensures uniform light emission to the edges of the radiation area, improving optical characteristics and preventing display irregularities, while also allowing for reduced power consumption and a compact design by utilizing space for electronic components.
Implementation Method 1
a plurality of reflecting surfaces that are formed at a plurality of ends of the arrangement surface and reflect light emitted from the plurality of light source
Data Source
AI summary
A direct-type backlight unit includes: an arrangement surface on which a plurality of light sources are arranged; and a plurality of reflecting surfaces that are formed at a plurality of ends of the arrangement surface and reflect light emitted from the plurality of light source. Light emitted from the light sources and light reflected from the plurality of reflecting surfaces irradiate to a radiation area surrounded by the plurality of reflecting surfaces. The plurality of reflecting surfaces are inclined at an angle that is smaller than 90 degrees with respect to an extension surface of the arrangement surface that extends toward the outside of the reflecting surface. The plurality of reflecting surfaces include reflecting surfaces having a large inclination angle and reflecting surfaces having an inclination angle that is smaller than the large inclination angle. The light sources that are arranged along the reflecting surfaces having the large inclination angle are closer to the edge of the radiation area than the other light sources that are arranged along the reflecting surfaces having the small inclination angle, in a plan view of the radiation area.