Light Guide Plate Sloped Portion Speckle Reduction
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Solution Overview
Problem
Conventional light guide plates for side-emitting backlight modules suffer from grated speckles near the light-incident surface and dipped beams due to compact diffusive microstructures and high light directivity, leading to uneven light distribution and energy loss.
Innovation Solution
A light guide plate design featuring a light-incident surface with a vertical portion perpendicularly connected to the light exit surface and a sloped portion inwardly inclined towards the reflection surface, where the perpendicular distance between the sloped portion and the light exit surface is smaller than the plate thickness, and the sloped portion has an inclined angle between 3° to 85°, preventing grated speckles and dipped beams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If compact diffusive microstructures are formed on the light-incident surface, then light distribution is improved, but grated speckles occur near the light-incident surface
Solution Approach 1:
The light-incident surface is segmented into two distinct portions: a vertical portion and a sloped portion. This segmentation allows each portion to serve different functions - the vertical portion manages light entry while the sloped portion prevents grated speckles, thereby resolving the contradiction between achieving good light distribution and avoiding harmful visual artifacts.
Solution Approach 2:
Different regions of the light-incident surface are given different geometric properties. The vertical portion has a perpendicular orientation to the light exit surface, while the sloped portion is inclined at a specific angle. This local differentiation allows the surface to simultaneously achieve compact microstructure benefits and eliminate grated speckles in different areas.
2Illumination intensity
If diffusive microstructures with high light directivity are formed on the reflection surface, then luminance is improved, but dipped beams occur in the light exit surface
Solution Approach 1:
Instead of modifying the reflection surface alone to control light directivity, the invention inverts the approach by modifying the light-incident surface geometry. The sloped portion of the light-incident surface redirects light paths in a way that achieves high luminance without creating the harmful dipped beams that result from conventional reflection surface modifications.
Solution Approach 2:
The solution moves from two-dimensional microstructure patterns to a three-dimensional geometric configuration. By introducing a sloped portion with a specific inclination angle, the invention adds a dimensional element that controls light propagation paths, achieving high luminance and preventing dipped beams through spatial geometry rather than surface patterning alone.
3Area of stationary object
If the distance between the visible area and the light-incident surface is reduced, then full screen and narrow bezel requirements are met, but light energy loss increases
Solution Approach 1:
The sloped portion is designed in advance with a specific inclination angle to pre-condition the light paths before they reach the visible area. This preliminary geometric arrangement ensures that light is properly distributed and directed even when the distance to the visible area is minimized, thereby reducing energy loss that would otherwise occur in compact designs.
Solution Approach 2:
The invention changes the geometric parameters of the light-incident surface by introducing a sloped portion with a controlled inclination angle. This parameter modification optimizes light propagation efficiency, allowing the system to achieve narrow bezel dimensions while maintaining low light energy loss through improved optical path management.
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 new design enhances even light distribution and reduces light energy loss by minimizing grated speckles and dipped beams, ensuring improved luminance uniformity and efficiency in backlight modules.
Implementation Method 1
The sloped portion is inwardly inclined from the vertical portion towards the reflection surface
Implementation Method 2
The reflection surface 912 and the light-incident surface 913 are respectively formed with diffusive microstructures so as to more evenly distribute the light exiting from the light exit surface 911
Data Source
AI summary
A light guide plate includes a plate body having a light exit surface, a reflection surface opposite to the light exit surface, and a light-incident surface connected between the light exit surface and the reflection surface and adapted to face a light source. The light-incident surface includes a vertical portion perpendicularly connected to the light exit surface, and a sloped portion connecting the vertical portion and the reflection surface. The sloped portion is inwardly inclined from the vertical portion towards the reflection surface.