Light Source Device Using Segmented Polarization for Projector Miniaturization
Solution Overview
Problem
Existing projector technologies face challenges in reducing the size of light source devices due to difficulties in manufacturing narrow-pitch polarization conversion elements, which are necessary for uniforming the polarization direction of light beams, leading to limitations in miniaturizing the projector.
Innovation Solution
A light source device configuration that emits multiple colored light beams with uniform polarization directions using a first light source section, polarization split elements, a diffusion element, and a wavelength conversion element, eliminating the need for narrow-pitch polarization conversion elements, and includes a second light source section and optical elements to separate and reflect light beams effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a polarization conversion element with narrow pitch is used to uniform the polarization direction of light beams, then the polarization uniformity is improved, but the device size cannot be reduced due to manufacturing difficulties
Solution Approach 1:
The patent divides the light beam into multiple wavelength bands (red, green, blue) using wavelength separation elements, and processes each band separately through dedicated optical paths. This segmentation allows the use of standard-pitch polarization conversion elements for each color channel rather than requiring a single narrow-pitch element for all wavelengths, thereby enabling device size reduction while maintaining polarization uniformity.
Solution Approach 2:
The patent introduces a spatial dimension by separating light beams of different wavelengths into different spatial paths using dichroic mirrors and beam splitters. Each wavelength band is then directed to its own polarization conversion element, transforming the problem from a single narrow-pitch requirement to multiple standard-pitch elements arranged in parallel spatial channels.
2Manufacturing precision
If a polarization conversion element with narrow pitch is used to uniform the polarization direction of light beams, then the polarization uniformity is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent segments the wavelength spectrum into multiple bands (red, green, blue) and assigns dedicated polarization conversion elements to each band. This allows each element to operate at standard pitch dimensions that are easier to manufacture, rather than requiring a single high-precision narrow-pitch element that would be difficult to fabricate and align.
Solution Approach 2:
The patent changes the operational parameters of the polarization conversion system by using multiple elements with standard pitch rather than one element with narrow pitch. This parameter change from pitch dimension to number of elements simplifies the manufacturing of each individual component while achieving the same overall polarization uniformity through the combined system.
3Volume of moving object
If standard-pitch polarization conversion elements are used instead of narrow-pitch elements, then the device size can be reduced, but the polarization uniformity may be compromised
Solution Approach 1:
By segmenting the light into multiple wavelength bands and processing each band through separate standard-pitch polarization conversion elements, the patent achieves both device size reduction and maintained polarization uniformity. Each standard-pitch element provides sufficient polarization conversion for its specific wavelength range, and the combined output maintains overall uniformity.
Solution Approach 2:
The patent applies polarization conversion separately to each wavelength band rather than attempting to convert all wavelengths simultaneously through a single element. This partial action approach allows each standard-pitch element to be optimized for its specific wavelength range, achieving adequate polarization uniformity for each band while using manufacturable standard-pitch components.
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 allows for the reduction in size of the light source device and projector while maintaining efficient light modulation and projection quality, enhancing color reproducibility and luminance with improved light use efficiency.
Implementation Method 1
a first polarization split element configured to transmit the first light beam entering the first polarization split element from the first light source section along a first direction and polarized in the first polarization direction toward the first direction, and configured to reflect the first light beam polarized in the second polarization direction toward a second direction crossing the first direction
Implementation Method 2
a second polarization split element disposed at the first direction side of the first polarization split element, and configured to reflect the first light beam which enters the second polarization split element along the first direction from the first polarization split element, and is polarized in the first polarization direction toward the second direction
Implementation Method 3
a diffusion element configured to diffuse the first light beam entering the diffusion element along the second direction from the first polarization split element, and configured to emit the first light beam diffused toward a third direction as an opposite direction to the second direction
Implementation Method 4
a wavelength conversion element disposed at the second direction side of the second polarization split element, configured to perform wavelength conversion on the first light beam which enters the wavelength conversion element along the second direction from the second polarization split element, and is polarized in the first polarization direction, and configured to emit a second light beam having a second wavelength band different from the first wavelength band toward the third direction
Data Source
AI summary
A light source device according to the present disclosure includes a first light source section for emitting first light in a first wavelength band, a first polarization split element for transmitting the first light polarized in a first polarization direction and reflecting the first light polarized in a second polarization direction, a second polarization split element for reflecting the first light with the first polarization direction, a diffusion element for diffusing the first light from the first polarization split element, a wavelength conversion element for emitting second light in a second wavelength band, a second light source section for emitting third light in a third wavelength band, a first optical element for reflecting the third light, and a second optical element for separating the second light into fourth light in a fourth wavelength band and a fifth light in the third wavelength band.