Light Guide Plate Minute Projection Structures Uniformity
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Solution Overview
Problem
The existing light guide plates in liquid crystal displays suffer from non-uniform light emission due to light absorption, resulting in reduced brightness and dark zones, particularly at locations distant from the light sources, leading to inefficiencies in optical energy transmission.
Innovation Solution
A light guide plate with minute projection structures coated with high reflectivity material on their side faces, arranged to decrease in density with distance from the light sources, enhances light reflection and reduces absorption losses, ensuring uniform light distribution by directing more light towards gaps between sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If microstructures are formed on the light guide plate to improve light guiding effect, then light guiding performance is improved, but optical energy is absorbed causing loss
Solution Approach 1:
The patent applies local quality by coating only specific regions of the light guide plate with high reflectivity material. The first region (near light sources) has high reflectivity coating to reduce absorption loss, while the second region (far from light sources) has different reflectivity characteristics to address brightness non-uniformity. This localized differentiation resolves the contradiction by optimizing each region's properties according to its specific functional requirements.
2Illumination intensity
If spot light sources are used with specific light exiting angles, then light emission is achieved, but dark zones form between light sources making light exit non-uniform
Solution Approach 1:
The patent divides the light guide plate into two distinct regions with different reflectivity characteristics. The first region near the light sources has high reflectivity to redirect light into the light guide plate and reduce absorption loss. The second region far from light sources has adjusted reflectivity to compensate for brightness non-uniformity and eliminate dark zones. This local quality differentiation directly addresses the uniformity problem caused by spot light sources.
Solution Approach 2:
The light guide plate is segmented into multiple regions with different optical properties. By dividing the surface into zones with varying reflectivity material coating, the patent creates distinct functional areas that work together to achieve uniform light exit, resolving the dark zone problem created by discrete spot light sources.
3Loss of energy
If high reflectivity material is coated on minute projection structures, then light reflection is enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent applies high reflectivity material coating selectively to only the first region of the light guide plate, rather than coating the entire surface. This partial action approach reduces manufacturing complexity compared to full-surface coating, while still achieving the primary goal of reducing light absorption loss in the critical region near the light sources.
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 improves light uniformity and reduces optical losses, maintaining brightness across the light exit surface and preventing dark zones, thereby enhancing the overall efficiency of the backlight module and display device.
Implementation Method 1
each of the minute projection structures comprising at least two side faces coated with a high reflectivity material, the at least two high reflectivity material coated side faces forming at least one included angle pointing toward the at least one light incidence surface
Data Source
AI summary
A light guide plate includes a light exit surface, a reflection surface opposite to the light exit surface, and at least one light incidence surface connecting to the light exit surface and the reflection surface. The reflection surface includes a plurality of minute projection structures projecting toward interior of the light guide plate. Each of the minute projection structures includes at least two side faces coated with a high reflectivity material. The at least two high reflectivity material coated side faces form at least one included angle pointing toward the at least one light incidence surface. The minute projection structures have a distribution density that is decreased with an increase of a distance thereof from the light sources.