Polarizing Light Guide Plate for Transparent Backlight Module
Solution Overview
Problem
Existing liquid crystal display devices with transparent backlights lack true transparency due to limitations in their backlight modules, particularly with four-color pixel designs like RGBW technology, which do not effectively allow both display and visibility through the display.
Innovation Solution
A backlight module incorporating a polarizing light guide plate, such as a Glan prism, that converts incident light into first and second polarized lights with perpendicular polarization directions, eliminating the need for additional polarizers and enhancing transparency by using a transparent medium with high transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional backlight module with four-color pixel design (RGBW) is used, then display functionality is achieved, but transparency is insufficient and light loss occurs
Solution Approach 1:
The patent combines the backlight module and polarizer into a single integrated polarizing light guide plate. The light guide plate simultaneously performs light guiding, polarization generation, and transparency functions, eliminating the need for separate polarizer components and reducing light loss at multiple interfaces.
Solution Approach 2:
The patent changes the optical parameters of the light guide plate by incorporating birefringent materials or specific structural designs that enable polarization generation while maintaining high light transmittance. This allows the plate to convert incident light into polarized light without significantly reducing overall transparency.
2Ease of operation
If additional polarizers are added to achieve proper polarization, then polarization control is improved, but device complexity and light loss increase
Solution Approach 1:
The light guide plate is designed to perform multiple functions simultaneously: light guiding, polarization generation, and structural support. This multi-functional design eliminates the need for separate polarizer components, reducing overall device complexity while maintaining effective polarization control.
Solution Approach 2:
The patent merges the functions of the light guide plate and polarizer into a single integrated component. This combination reduces the number of optical interfaces and alignment requirements, simplifying the overall structure while maintaining precise polarization control.
3Illumination intensity
If a polarizing light guide plate is used to improve transparency, then light transmittance is enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent achieves polarization functionality by modifying the optical parameters of conventional light guide plate materials through birefringence or specific structural geometries. This approach allows manufacturing using existing light guide plate fabrication processes while adding polarization capability, rather than requiring entirely new manufacturing techniques.
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 transparency and luminance in display devices by reducing light loss and allowing visibility through the display, enabling true transparent display functionality without additional polarizers.
Implementation Method 1
the first polarized light is generated by the reflection of the incident light within the polarizing light guide plate
Implementation Method 2
the first polarized light exits from the first bottom surface of the first prism after being reflected at the inclined surface
Data Source
AI summary
A backlight module and a display device are provided. The backlight module includes a polarizing light guide plate configured to convert incident light into first polarized light and second polarized light, a polarization direction of the first polarized light being perpendicular to a polarization direction of the second polarized light.