Reflective Polarizer Module Light Recycling Improving Sheet
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Solution Overview
Problem
The luminance of liquid crystal displays is restricted due to specific polarized light being recycled inside the backlight unit, rather than being transmitted to the liquid crystal panel, resulting in reduced overall display brightness.
Innovation Solution
A reflective polarizer module is introduced, featuring a light recycling improving sheet positioned at the bottom of the reflective polarizer sheet, which randomly changes the polarized direction of non-transmitted light, allowing it to be reflected and transmitted back through the polarizer, enhancing light recycling and overall luminance. This module includes a first light collecting sheet with a progressive cross-sectional area reduction and a high-polymer light recycling improving sheet with birefringence properties, such as polyester or polycarbonate, to diffuse and redirect light effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a reflective polarizer sheet is used to transmit only specific polarized light, then the luminance of the liquid crystal display is enhanced, but the light that is not transmitted is reflected downward and recycled inside the backlight, restricting the overall luminance
Solution Approach 1:
The patent introduces a light recycling improving sheet with specific optical parameters (birefringence, diffusion properties) to change the polarization state of reflected light. This parameter change enables the recycled light to be transmitted through the reflective polarizer again, converting previously wasted reflected light into useful transmitted light and thereby resolving the contradiction between luminance enhancement and light energy loss.
Solution Approach 2:
The light recycling improving sheet acts as an intermediary element between the reflective polarizer sheet and the light guide plate. It modifies the polarization state of reflected light before it re-enters the optical path, enabling efficient light recycling without compromising the polarizer's selective transmission function, thus resolving the energy loss issue while maintaining luminance enhancement.
2Illumination intensity
If a light recycling improving sheet is added to change the polarized direction of reflected light, then light recycling and overall luminance are enhanced, but the thickness of the backlight unit increases
Solution Approach 1:
The patent employs a light recycling improving sheet in the form of a thin film with optimized optical properties. This thin film structure provides the necessary polarization modification function while minimizing thickness increase, allowing the backlight unit to achieve enhanced light recycling and overall luminance without significant increase in overall thickness.
3Illumination intensity
If conventional light collecting sheets with prisms are used, then light collection is achieved, but Newton rings and other optical issues occur
Solution Approach 1:
The patent applies a light recycling improving sheet with locally optimized optical properties at the bottom of the reflective polarizer sheet. This local intervention modifies the polarization state of reflected light without requiring conventional prism structures, achieving effective light collection and recycling while eliminating Newton rings and other optical interference issues associated with traditional light collecting sheets.
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 enhances light recycling and transmission, increasing the overall luminance of the display while reducing the thickness of the backlight unit and eliminating issues like Newton rings, thereby improving the display's brightness and slimness.
Implementation Method 1
a light recycling improving sheet with birefringence properties, such as polyester or polycarbonate, to diffuse and redirect light effectively
Implementation Method 2
selectively transmitting the light by having a plurality of stacked layers having mutually different refractive indices
Implementation Method 3
a first light collecting sheet including a first structuring pattern having a first unit light collector, a cross-sectional area of which is reduced progressively upward, which is disposed continuously in a repetitive manner, and collecting a light transmitted from below
Implementation Method 4
a reflection plate stacked on a lower surface of the light guide plate and reflecting the light transmitted through the light guide plate upwardly
Data Source
AI summary
The present disclosure provides a reflective polarizer module characterized by comprising: a first light collecting sheet including a first structuring pattern having a first unit light collector, the cross-sectional area of which is reduced progressively upward, which is disposed continuously in a repetitive manner, and collecting a light transmitted from below; a reflective polarizer sheet disposed in a stacked configuration on the top of the first light collecting sheet, and selectively transmitting the light by having a plurality of stacked layers having mutually different refractive indices; and a light recycling improving sheet disposed at the bottom of the reflective polarizer sheet, and randomly changing the polarized direction of the light which is not transmitted through the reflective polarizer sheet but is reflected downward.