Wavelength Selective Polarization Splitter for Image Projection Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image projection apparatuses face challenges in achieving high image quality due to unintended mixing of blue light with yellow or other colors, leading to image quality degradation and reduced brightness.
Innovation Solution
The apparatus incorporates a wavelength-selective polarization splitter and a color wheel with specific spectral transmittance characteristics, along with an optical component having tailored reflectance and transmittance properties, to switch optical paths and separate blue light from generated fluorescence, ensuring pure color projection and enhanced brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional illumination system is used to project images, then the system structure is simple, but blue light mixes with yellow or other colors causing image quality degradation
Solution Approach 1:
The patent segments the optical path into multiple distinct paths: a first optical path for blue light transmission and a second optical path for yellow light transmission. The wavelength selective polarization splitter divides the illumination light into these separate paths based on wavelength and polarization state, preventing blue light contamination in the yellow light path and thereby improving image quality while managing system complexity through structured segmentation
Solution Approach 2:
The patent introduces a wavelength selective polarization splitter as an intermediary component between the light source and the projection optical system. This mediator selectively transmits and reflects different wavelengths based on polarization, enabling precise control over which wavelengths reach which optical path, thus preventing unwanted color mixing and improving image quality
2Manufacturing precision
If blue light is transmitted directly without separation, then the system is simple, but blue light contamination reduces color accuracy
Solution Approach 1:
The patent applies local quality by giving different optical components different spectral transmission characteristics. The wavelength selective polarization splitter has specific transmittance and reflectance properties for different wavelengths and polarization states, allowing blue light to be transmitted in the first path while yellow light is reflected to the second path, ensuring each path receives only the intended wavelengths for optimal color accuracy
Solution Approach 2:
The patent employs dynamic optical path switching based on the polarization state of light. The quarter wavelength plate converts linearly polarized blue light to circularly polarized light, which then interacts differently with the wavelength selective polarization splitter, enabling the system to dynamically route different wavelengths through different paths based on their polarization properties
3Illumination intensity
If optical paths are not switched, then the device is simple, but brightness is reduced due to light mixing
Solution Approach 1:
The patent segments the optical system into distinct first and second optical paths that are spatially separated. The wavelength selective polarization splitter directs blue light through the first path and yellow light through the second path, preventing light mixing and ensuring that each path delivers maximum brightness for its intended color without contamination from other wavelengths
Solution Approach 2:
The wavelength selective polarization splitter serves multiple functions simultaneously: it acts as a beam splitter, a wavelength selector, and a polarization controller all in one component. This multi-functionality enables the system to achieve high brightness through efficient light routing while minimizing the number of separate components needed, thereby managing device complexity
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 effectively reduces image quality degradation by minimizing blue light contamination and enhancing brightness, resulting in improved color accuracy and projection quality.
Implementation Method 1
a fluorescence generator to generate, with excitation light of the first light, fluorescence having a wavelength longer than a wavelength of the first light
Implementation Method 2
a polarization converter to alternately change the first light between linearly polarized light and circular polarized light
Implementation Method 3
The wavelength selector has a first area to transmit the first light through the first area, and a second area to reflect the first light and transmit the fluorescence through the second area
Data Source
AI summary
An image projection apparatus includes an illumination device, an optical-path forming section, an image forming element, a projection optical section, and an optical component. The illumination device includes a fluorescence generator; a wavelength selector having a first area and a second area; and a polarization converter; and an optical-path switcher. The wavelength selector alternately sets the first area and the second area in an optical path of the first light in a temporal manner. The illumination device switches a first optical path and a second optical path based on a setting of the wavelength selector.