Light Guide Buffer Plate Prism Pattern for Backlight Uniformity
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Solution Overview
Problem
Edge light-type back light units for liquid crystal displays suffer from poor luminance and uniformity issues, particularly in the end region adjacent to the light source, leading to a poor-visibility zone with unmixing of colors, which deteriorates user visibility.
Innovation Solution
A back light unit is designed with a light guide buffer plate featuring a second prism pattern on its light-emitting surface and a first prism pattern on the light guide panel's light-receiving surface, along with a reflection unit and optical sheets, to uniformly distribute light without altering the light guide panel's structure, enhancing visibility and color mixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional edge light-type back light unit is used with a light guide panel, then the structure is simple and manufacturing is easy, but the luminance and color uniformity are poor in the end region adjacent to the light source
Solution Approach 1:
A buffer plate is introduced as an intermediary component between the light source and the light guide panel. This buffer plate includes a buffer light guide portion with a first refractive index and a first prism pattern on its light emitting surface, which mediates the light distribution to improve luminance uniformity in the end region without requiring changes to the light guide panel structure.
Solution Approach 2:
The lighting system is segmented into distinct functional components: the light source, the buffer plate with buffer light guide portion, and the light guide panel. This segmentation allows the buffer plate to specifically address the luminance uniformity issue in the end region while the light guide panel maintains its original structure for overall light distribution.
2Illumination intensity
If additional LEDs are installed to improve luminance in the end region, then visibility is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
Instead of adding more light sources (LEDs), the invention uses a buffer plate as an intermediary to redistribute existing light more uniformly. The buffer light guide portion and first prism pattern on its light emitting surface redirect light into the end region, improving visibility without the need for additional LEDs or increased manufacturing complexity.
Solution Approach 2:
The invention replaces the mechanical approach of adding more light-emitting components with an optical approach using the buffer plate's refraction and reflection properties. The first prism pattern on the buffer plate's light emitting surface optically redirects light to improve uniformity without requiring additional electrical components or complex wiring.
3Illumination intensity
If the light guide panel structure is modified to improve color mixing, then color uniformity is improved, but manufacturing precision requirements increase
Solution Approach 1:
The buffer plate serves as an intermediary that performs the color mixing function before light enters the light guide panel. The first prism pattern on the buffer plate's light emitting surface and the reflection unit on its bottom surface work together to mix colors uniformly, eliminating the need to modify the light guide panel structure or increase manufacturing precision requirements for the panel itself.
Solution Approach 2:
Color mixing is performed preliminarily in the buffer plate before light enters the light guide panel. The first prism pattern and reflection unit in the buffer plate pre-mix the colors, so that when light reaches the light guide panel, uniform color distribution is already achieved, eliminating the need for complex patterns or high-precision manufacturing in the light guide panel.
4Illumination intensity
If a buffer plate with first prism pattern is added between light source and light guide panel, then luminance and color uniformity are improved, but device complexity increases
Solution Approach 1:
The buffer plate is designed to perform multiple functions: it acts as a light guide (buffer light guide portion), provides refraction through the first prism pattern on its light emitting surface, and enables reflection through the reflection unit on its bottom surface. This multi-functionality allows a single component to address luminance uniformity, color mixing, and light distribution without requiring multiple separate components.
Solution Approach 2:
The buffer plate combines the functions of light guiding, refraction, and reflection into a single integrated component. The buffer light guide portion, first prism pattern, and reflection unit are merged in one piece, reducing the need for multiple separate components and minimizing the increase in device complexity while achieving improved luminance and color 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
The solution effectively improves luminance and color uniformity across the display by uniformly transferring light from the source to the light guide panel, reducing the need for additional LEDs and lowering manufacturing costs while maintaining uniformity.
Implementation Method 1
a first prism pattern on the light guide panel's light-receiving surface and whose light-emitting vertical surface is provided with a second prism pattern
Implementation Method 2
a reflection unit and optical sheets, to uniformly distribute light
Data Source
AI summary
There is provided a back light unit having a light guide buffer plate. The back light unit having a light guide buffer plate includes a light source for generating the light when a power source is applied; a light guide panel whose light-receiving vertical surface that the light emitted from the light source enters is provided with a first prism pattern and whose bottom surface is provided with a refraction pattern, thereby converting the incident light from the light-receiving vertical surface into a surface light source; a reflection unit disposed in a bottom surface of the light guide panel to reflect light toward the light guide panel; and a buffer disposed between the light source and the light guide panel and whose light-emitting vertical surface corresponding to the light-receiving vertical surface of the light guide panel is provided with a second prism pattern. The back light unit can be useful to improve visibility, a mixing property and uniformity by basically removing a poor-visibility zone, which is formed in an end of the light guide panel, without any changes in the structure of the light guide panel.