Single-Imager Projection Engine V-Notch PBS Assembly
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Solution Overview
Problem
Conventional single-imager projection engine assemblies have low light utilization due to the inefficiency in using illumination light in orthogonal polarization states, resulting in limited projection brightness and increased light consumption.
Innovation Solution
A single-imager projection engine assembly is designed with a reflective polarization modulation imager, a pair of polarization beam splitting films in a V-notch configuration, and a reflective quarter wave composite plate, which converts and reflects illumination light in both polarization states to maximize light utilization, allowing almost all light from the source to be used for projection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single PBS assembly and single reflective polarization modulation imager are used in the simplest configuration, then the device complexity is reduced, but the light utilization efficiency deteriorates because only limited portion of illumination light in one polarization state is used
Solution Approach 1:
The PBS assembly is segmented into multiple PBS elements (first PBS, second PBS) with different polarization state selections. Each PBS element selectively transmits or reflects light based on its specific polarization state, enabling the system to process both orthogonal polarization states separately and combine them, thereby improving light utilization efficiency while maintaining reasonable device complexity
Solution Approach 2:
The projection engine assembly is designed to handle multiple polarization states through a unified optical path. By incorporating multiple PBS elements that work together, the system achieves multi-functionality in processing both first and second polarization states, converting previously wasted light into useful projected light without requiring completely separate optical paths
2Device complexity
If only illumination light in one polarization state is utilized for illuminating the reflective polarization modulation imager, then the device structure remains simple, but the projection brightness is limited due to low light utilization
Solution Approach 1:
The system ensures continuous useful action by processing both orthogonal polarization states through the optical path. The first PBS handles the first polarization state while the second PBS handles the second polarization state, and both paths are continuously active, ensuring that all illumination light contributes to projection brightness without interruption or waste
Solution Approach 2:
The system changes the polarization state parameter of illumination light by using PBS elements with different polarization selections. By adjusting which polarization states are transmitted or reflected at different PBS elements, the system converts light that would otherwise be wasted into useful projected light, thereby increasing projection brightness
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 improves light utilization and projection brightness, reducing light consumption while maintaining high image quality and polarization efficiency.
Implementation Method 1
a first polarization beam splitting film and a second polarization beam splitting film in a V-notch pairing configuration. The first polarization beam splitting film reflects the illumination light in first polarization state to the reflective polarization modulation imager
Implementation Method 2
the second polarization beam splitting film and the reflective quarter wave composite plate in conjunction convert the illumination light in second polarization state passing through the first polarization beam splitting film to first polarization state
Implementation Method 3
A reflective liquid-crystal-on-silicon (LCOS) imager is a kind of reflective microdisplay imager, which rotates and modulates the polarization state of incident light
Implementation Method 4
Combined illumination is modulated, polarization rotated and reflected by the reflective polarization modulation imager back to the PBS assembly for projection through the projection lens
Data Source
AI summary
A single-imager projection engine assembly includes a light source, a reflective polarization modulation imager, a reflective quarter wave composite plate, a projection lens system, and a PBS assembly which includes a first polarization beam splitting film and a second polarization beam splitting film in a V-notch pairing configuration. The first polarization beam splitting film reflects the illumination light in first polarization state to the reflective polarization modulation imager, while the second polarization beam splitting film and the reflective quarter wave composite plate in conjunction convert the illumination light in second polarization state passing through the first polarization beam splitting film to first polarization state and reflects the converted to the reflective polarization modulation imager. Combined illumination is modulated, polarization rotated and reflected by the reflective polarization modulation imager back to the PBS assembly for projection through the projection lens.