Polarization Conversion Element Gap Tolerance via Film Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polarization conversion efficiency in polarization separation units degrades due to manufacturing variations causing gaps between polarization separation surfaces, leading to light not entering the polarization conversion area.
Innovation Solution
A polarization conversion element design where the first and second polarization separation films are terminated at positions separate from the light incidence surfaces, with the first surface and second surface opposed to each other, reducing gaps and enhancing light entry, and optionally including a reflecting element between the optical blocks to inhibit light transmission through gaps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If polarization separation surfaces are disposed separately from each other in the light incidence surface due to manufacturing variations, then the structure allows for manufacturing flexibility, but the polarization conversion efficiency degrades because light entering the gap area fails to enter the polarization separation surface
Solution Approach 1:
The patent extends the polarization separation surfaces beyond the light incidence surface into the bonding surface region. By adding this dimensional extension, light that would otherwise enter gaps at the light incidence surface is redirected to enter the polarization separation surfaces through the extended regions, thereby maintaining high polarization conversion efficiency while preserving manufacturing flexibility
Solution Approach 2:
The patent introduces a reflecting film as an intermediary element positioned between the polarization separation surfaces. This reflecting film redirects light that enters the gap region between polarization separation surfaces, ensuring that the light eventually reaches the polarization separation surfaces and undergoes polarization conversion, thus preventing efficiency degradation
2Reliability
If polarization separation surfaces are disposed in contact with each other in the light incidence surface, then the polarization conversion efficiency is maximized, but the manufacturing precision requirements increase due to sensitivity to manufacturing variations
Solution Approach 1:
The patent resolves the precision-efficiency contradiction by extending the polarization separation surfaces into the bonding surface dimension. This dimensional extension creates a larger effective area for light entry, making the system less sensitive to misalignments at the light incidence surface while maintaining high polarization conversion efficiency
Solution Approach 2:
The patent designs the polarization separation surfaces to extend beyond the light incidence surface into the bonding surface region, creating a buffer zone that compensates for potential manufacturing variations. This beforehand cushioning ensures that even if alignment is not perfect, light can still enter the polarization separation surfaces through the extended regions
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 reduces light loss and maintains high polarization conversion efficiency even with manufacturing variations, and can reduce manufacturing costs by ensuring equal substrate thicknesses.
Implementation Method 1
a first polarization separation film... a second polarization separation film... the first polarization separation film is disposed so as to be opposed to the second polarization separation film
Implementation Method 2
a first reflecting film... a second reflecting film... light entering an area between the polarization separation surfaces
Data Source
AI summary
An aspect of the polarization conversion element according to the invention is directed to a polarization conversion element including a first optical block including a first polarization separation film, a first reflecting film, a first surface, and a first light incidence surface, and a second optical block including a second polarization separation film, a second reflecting film, a second surface, and a second light incidence surface, wherein the first optical block and the second optical block are bonded to each other so that the first surface and the second surface are opposed to each other, the first polarization separation film is disposed so as to be opposed to the second polarization separation film via the first surface and the second surface, and the first polarization separation film is terminated at a position in the first surface separate from the first light incidence surface.