Light Guide Plate Uniform Brightness Diffuse Reflection Pattern
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Solution Overview
Problem
Conventional liquid crystal display (LCD) devices experience display nonuniformity due to low brightness at both sides of the liquid crystal panel, primarily caused by the non-emissive area of the lamp in the backlight unit, leading to uneven light distribution and brightness across the display area.
Innovation Solution
A light guide plate with a diffuse reflection pattern on its light emitting and lateral surfaces, which diffuses and reflects light to achieve uniform brightness across the display area, including a prism pattern on the rear surface and a reflection pattern to optimize light distribution, reducing the non-emissive area effects and enhancing brightness at corners.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a lamp is used as the light source in the backlight unit, then light can be generated to illuminate the liquid crystal panel, but brightness becomes non-uniform across the display area with lower brightness at both sides and bright lines near the lamp
Solution Approach 1:
The light guide plate is divided into multiple functional regions with different surface characteristics: a first region with a first surface roughness and a second region with a second surface roughness. This segmentation allows different areas to perform different light control functions, with the first region managing light from the lamp area and the second region managing light from the opposite side, thereby achieving uniform brightness distribution across the entire display area.
Solution Approach 2:
Different regions of the light guide plate are assigned different surface roughness values. The first region has a first surface roughness optimized for light extraction near the lamp, while the second region has a second surface roughness optimized for light extraction from the opposite side. This local differentiation of surface properties enables uniform light distribution without requiring a completely uniform structure throughout the entire plate.
2Ease of manufacture
If the light guide plate has a uniform structure throughout, then manufacturing is simple, but brightness is non-uniform at corners and edges due to the non-emissive area of the lamp
Solution Approach 1:
The light guide plate incorporates a second prism pattern in the second region with different prism characteristics (different pitch, height, or shape) compared to the first prism pattern. This local differentiation allows the second region to specifically compensate for the non-emissive area effect at the opposite side, enhancing brightness at corners and edges without requiring complete structural redesign of the entire plate.
Solution Approach 2:
The invention adds a vertical dimension by incorporating prism structures into the light guide plate. The first prism pattern and second prism pattern create three-dimensional light guiding paths that redirect light toward the liquid crystal panel, particularly enhancing light extraction from regions that would otherwise be dark corners and edges.
3Illumination intensity
If the light guide plate uses high surface roughness throughout, then light diffusion is maximized, but light extraction efficiency decreases and brightness overall is reduced
Solution Approach 1:
The light guide plate uses different surface roughness values in different regions. The first region near the lamp uses a first surface roughness optimized for light diffusion in that specific area, while the second region uses a second surface roughness optimized for light extraction from the opposite side. This localized approach allows each region to perform its specific function optimally without compromising overall light extraction efficiency.
Solution Approach 2:
The invention creates a dynamic light management system where different regions of the light guide plate actively control light in different ways. The first prism pattern and second prism pattern work together to dynamically redirect light paths, ensuring that light is efficiently extracted from both the lamp side and the opposite side while maintaining appropriate diffusion characteristics.
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 ensures uniform brightness across the liquid crystal display by diffusing and reflecting light effectively, reducing the brightness disparities at the corners and edges, thus improving the overall display quality and eliminating the bright line defects.
Implementation Method 1
a diffuse reflection pattern is formed on at least any one of the light emitting surface and the lateral surfaces to diffuse-reflect the light incident to the lateral surfaces
Implementation Method 2
a rear surface formed opposite to the light emitting surface and including a prism pattern which reflects the incident light to the light emitting surface
Data Source
AI summary
A light guide plate includes a light incident surface to which light is incident as incident light, an opposite surface formed opposite to the light incident surface, a light emitting surface through which the incident light is emitted, a rear surface formed opposite to the light emitting surface and including a prism pattern which reflects the incident light to the light emitting surface, and lateral surfaces, wherein a diffuse reflection pattern is formed on at least any one of the light emitting surface and the lateral surfaces to diffuse-reflect light incident to the lateral surfaces, thus rendering a brightness at both the opposite surface and the light incident surface substantially uniform.