Light Guide Plate Mountain-Range Shapes Polarization Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display devices experience significant light loss due to reflections and absorption within the light guide plate, particularly from S-polarized light, which is not effectively utilized for exit emission.
Innovation Solution
The light guide plate features protrusions and recesses with specific mountain-range shapes on its surfaces, converting S-polarized light to P-polarized light upon reflection, thereby reducing internal reflections and enhancing exit light efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light travels inside the light guide plate and reflects off the front surface interface to exit, then light can be emitted from the front surface, but S-polarized light has high reflectivity causing light loss
Solution Approach 1:
The invention changes the polarization state parameter of the light by using the first mountain-range shapes to convert S-polarized light to P-polarized light. This parameter change reduces reflectivity at the front surface interface, thereby reducing light loss while maintaining exit light intensity.
Solution Approach 2:
The invention converts the harmful effect of S-polarized light reflection (which causes light loss) into a beneficial effect by transforming it into P-polarized light through the first mountain-range shapes. The converted P-polarized light has lower reflectivity and can exit more efficiently, turning the original problem into a solution.
2Reliability
If the polarizer transmits only P-polarized light, then the liquid crystal display panel receives properly polarized light, but S-polarized light exiting from the light guide plate is blocked and absorbed
Solution Approach 1:
The invention performs preliminary action by converting S-polarized light to P-polarized light before the light reaches the polarizer. The first mountain-range shapes transform the polarization state in advance, ensuring that the light is already in the desired P-polarized state and will not be blocked or absorbed by the polarizer.
3Illumination intensity
If protrusions and recesses with first mountain-range shapes are formed on the light guide plate, then P-polarized light is increased in exit light, but the device structure becomes more complex
Solution Approach 1:
The invention segments the light guide plate surface into specific geometric patterns (first mountain-range shapes with paired side surfaces at defined angles). This segmentation creates the necessary optical function for polarization conversion while maintaining a structured, manufacturable form rather than a random complex structure.
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 significantly increases the proportion of P-polarized light exiting the plate, minimizing light loss and improving the efficiency of the liquid crystal display device by optimizing the polarizer's transmission properties.
Implementation Method 1
the formation of the first mountain-range shapes enables the increase in P-polarized light in the exit light from the front surface of the light guide plate. The P-polarized light is lower in reflectivity than the S-polarized light and accordingly has a smaller component which reflects off an interface on the front surface side
Data Source
AI summary
A light guide plate is for reflecting incident light from an end surface thereof in an inside to obtain surface emission from a front surface thereof. The light guide plate includes protrusions and recesses formed on one of the front surface and a rear surface on an opposite side of the front surface. The protrusions and recesses are formed of a shape in which first mountain-range shapes each including a first ridge continuing along a first direction, which is a direction toward the inside from the end surface, and second mountain-range shapes each including a second ridge continuing along a second direction intersecting with the first direction are combined. Each first mountain-range shape includes a pair of first side surfaces on both sides of the first ridge. Each second mountain-range shape includes a pair of second side surfaces on both sides of the second ridge.