Light Source Device Uniform Polarization Compact Projector
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Solution Overview
Problem
Existing projector designs face challenges in reducing size due to the need for polarization conversion devices with narrow pitch, which are difficult to manufacture, especially when using liquid crystal panels with non-uniformly polarized light sources.
Innovation Solution
A light source device emitting uniformly polarized red, green, and blue light beams without the need for narrow pitch polarization conversion elements, utilizing a configuration with polarization split elements, retardation elements, and diffusion elements to separate and align the light beams efficiently, allowing for a compact projector design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conventional light source device with non-uniformly polarized light is used, then the projector can be designed with a single liquid crystal panel, but the size cannot be reduced due to the need for narrow pitch polarization conversion elements that are difficult to manufacture
Solution Approach 1:
The invention changes the polarization state parameter of the light source itself. By using polarization-separating elements to divide light into S-polarized and P-polarized components, and then using wavelength conversion elements with different polarization characteristics, the system achieves uniform polarization without requiring narrow pitch polarization conversion elements in the optical path, thus resolving the manufacturing difficulty while enabling compact projector design
Solution Approach 2:
The invention segments the white light from the light source into different polarization components (S-polarized and P-polarized light) using polarization-separating elements. This segmentation allows each polarization component to be processed independently through wavelength conversion, enabling uniform polarization output without requiring complex narrow pitch polarization conversion devices
2Stability of the object's composition
If narrow pitch polarization conversion elements are used to achieve uniform polarization, then the light can be uniformly polarized, but the device complexity and manufacturing difficulty increase significantly
Solution Approach 1:
Instead of using complex narrow pitch polarization conversion elements to change polarization uniformity, the invention changes the approach by separating light into different polarization states first, then using wavelength conversion elements whose optical characteristics differ by polarization. This parameter-based differentiation achieves uniform polarization output through a simpler system configuration
Solution Approach 2:
The invention introduces polarization-separating elements as intermediaries that divide the incident light into S-polarized and P-polarized components. These separated components then pass through wavelength conversion elements that act as mediators with polarization-dependent optical characteristics, ultimately producing uniformly polarized light without requiring complex polarization conversion devices
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 solution enables a smaller projector size with improved efficiency by eliminating the need for narrow pitch polarization conversion devices and allowing for effective use of semiconductor lasers, reducing speckle and achieving uniform illumination.
Implementation Method 1
a first polarization split element configured to transmit the first light beam and the second light beam having a first polarization direction out of the first light beam, the second light beam, and the third light beam entering the first polarization split element
Implementation Method 2
a first retardation element which is disposed between the first polarization split element and the second polarization split element, and is configured to provide a phase difference to light in the second wavelength band
Implementation Method 3
a first diffusion element which is disposed at the second direction side of the first polarization split element, and configured to diffuse the third light beam which enters the first diffusion element along the second direction from the first polarization split element
Data Source
AI summary
A light source device according to the present disclosure includes a light source unit configured to emit a first light beam, a second light beam, and a third light beam, a first polarization split element configured to transmit the first light beam and the second light beam and reflect the third light beam, a second polarization split element configured to transmit the first light beam and reflect the second light beam, a first retardation element, a first diffusion element configured to diffuse the third light beam, a second diffusion element configured to diffuse the second light beam, and a third diffusion element configured to diffuse the first light beam. The first retardation element converts a polarization direction of the second light beam from the first polarization split element, and converts a polarization direction of the another part of the second light beam from the second polarization split element.