Polarization Conversion Apparatus for Projection Systems
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Solution Overview
Problem
Projection optical systems using LCD and LCOS micro-displays face inefficiencies due to the need for polarized light, which results in 50% light loss when using unpolarized light sources, as conventional methods for polarization conversion are not effective in reusing wasted polarization.
Innovation Solution
A polarization conversion apparatus comprising a first optical device for angle-converting unpolarized light into different linear polarizations, utilizing a Fly Eye Lens with Micro Lens Arrays and optical elements like holograms and wave plates to efficiently convert unpolarized light into usable polarized light without loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a polarization plate is used to produce polarized light from unpolarized light sources, then the required polarization is achieved, but 50% light loss occurs due to absorption or reflection of perpendicular polarization
Solution Approach 1:
The patent changes the polarization state parameters of light through a multi-stage process: first converting unpolarized light to circular polarization, then to linear polarization at a specific angle, and finally adjusting to the required polarization state. This parameter transformation approach eliminates light loss by avoiding direct absorption while achieving the desired polarization orientation.
Solution Approach 2:
The patent employs a composite optical system combining multiple functional elements: a polarization conversion element (PCE) with specific optical properties, quarter-wave plates, half-wave plates, and beam splitters. Each component contributes a specific function, and their combination achieves efficient polarization conversion without the 50% light loss inherent in single polarization plate approaches.
2Productivity
If conventional polarization plates are used in projection optical systems, then polarized light is produced, but light efficiency is reduced due to wasted polarization
Solution Approach 1:
The patent recovers polarization that would otherwise be wasted by implementing a polarization conversion apparatus that transforms the polarization state of light passing through the projection system. The system captures and reuses polarization components that would normally be absorbed or reflected, converting them into useful polarized light for the projection optical system.
Solution Approach 2:
The patent implements a feedback mechanism where the polarization state of light is continuously monitored and adjusted through the PCE and associated optical elements. The system uses wave plates and beam splitters to feedback-control the polarization state, ensuring optimal light efficiency by redirecting and converting polarization components that would otherwise be lost.
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 apparatus effectively converts unpolarized light into linear polarizations, enabling its use in optical systems without light loss, thereby increasing the available light and improving system efficiency.
Implementation Method 1
a first optical device capable of angle-converting incident unpolarized light to allow a polarization direction to be emitted in mutually different first and second linear polarizations
Implementation Method 2
an angle conversion passive element separating the incident unpolarized light to angle-converted right-circular polarization and left-circular polarization
Implementation Method 3
an FEL (Fly Eye Lens) including first and second MLAs (Micro Lens Arrays) arrayed with first and second micro lenses, where first and second linear polarizations of the first optical device incident on the first micro lenses are divided and condensed
Implementation Method 4
first and second linear polarizations of the first optical device incident on the first micro lenses are divided and condensed on an upper side and a bottom side of the second micro lenses
Implementation Method 5
an optical conversion element converting the angle-converted right-circular polarization and left-circular polarization converted by the angle conversion passive element to first and second linear polarizations
Implementation Method 6
a second optical device converting the first and second linear polarizations condensed on the upper side or the bottom side of the second MLA at the FEL to any one polarization of the first and second linear polarizations
Data Source
AI summary
Disclosed is a polarization conversion apparatus, the apparatus including a first optical device capable of angle-converting incident unpolarized light to allow a polarization direction to be emitted in mutually different first and second linear polarizations, an FEL (Fly Eye Lens) including first and second MLAs (Micro Lens Arrays) arrayed with first and second micro lenses, where first and second linear polarizations of the first optical device incident on the first micro lenses are divided and condensed on an upper side and a bottom side of the second micro lenses of the second MLA, and a second optical device converting the first and second linear polarizations condensed on the upper side or the bottom side of the second MLA at the FEL to any one polarization of the first and second linear polarizations and emitting the polarization.