Light Source Apparatus Polarization Uniformity
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Solution Overview
Problem
Existing light source apparatuses using laser light sources suffer from uneven distribution of intensity for different colors due to the orientation of the polarization plane, leading to non-uniformity in light intensity across the light source plane.
Innovation Solution
Incorporating a polarization conversion element with a p/s-polarizing beam splitter film and a fluorescent substance excited by a laser beam, along with a supporting member that positions the polarization plane of the laser beam between p- and s-polarized light components, ensuring an optimal angle for equal distribution of p- and s-polarization components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If laser light is used as the light source, then the brightness and color reproduction are improved, but the uniformity of light intensity distribution deteriorates due to polarization effects
Solution Approach 1:
The patent changes the polarization state parameter of the laser light by introducing a polarization conversion element that transforms the linearly polarized laser light into circularly polarized light. This parameter change ensures that when the light passes through the scattering element, both p-polarized and s-polarized components are equally distributed, resolving the uniformity issue while maintaining the brightness benefits of laser light.
2Manufacturing precision
If a polarization conversion element is added to convert polarization, then the uniformity of light distribution is improved, but the device complexity increases
Solution Approach 1:
The polarization conversion element serves multiple functions: it converts the polarization state of laser light to circular polarization, ensures uniform distribution of p- and s-polarized components, and maintains compatibility with existing optical systems. This multi-functionality justifies the addition while minimizing the impact on overall system complexity.
3Illumination intensity
If fluorescence is used to convert laser light, then the color reproduction is improved, but the optical loss increases due to random polarization
Solution Approach 1:
The patent applies preliminary action by converting the laser light to circularly polarized light before it enters the scattering element containing fluorescence. This preliminary polarization conversion ensures that the fluorescence is excited uniformly in all polarization directions, maximizing light utilization efficiency and reducing optical losses that would otherwise occur with randomly polarized fluorescence.
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 ensures a uniform distribution of light intensity across the light source plane, reducing non-uniformity and enhancing image quality in projectors by evenly distributing the intensity of each color.
Implementation Method 1
a p/s-polarizing beam splitter film capable of separating polarization components of incident light into p-polarization component and s-polarization component
Implementation Method 2
a fluorescent substance capable of emitting visible light as the incident light that is incident on the p/s-polarizing beam splitter film, which visible light is generated by that the fluorescent substance is excited by excitation light
Implementation Method 3
a light source element capable of emitting a laser beam having a predetermined wavelength as the excitation light to irradiate the fluorescent substance with the excitation light
Data Source
AI summary
A light source apparatus includes a polarization conversion element, a fluorescent substance and a light source element. The polarization conversion element has a p/s-polarizing beam splitter film to separate polarization components of incident light into p-polarization component and s-polarization component. The fluorescent substance emits visible light as the incident light that is incident on the p/s-polarizing beam splitter film, which visible light is generated by that the fluorescent substance is excited by excitation light, and has a wavelength of longer wavelength region than a wavelength of the excitation light. The light source element emits a laser beam having a predetermined wavelength as the excitation light to irradiate the fluorescent substance with the excitation light so that a laser beam having a polarization plane between the polarization plane of p-polarized light and the polarization plane of s-polarized light exiting from the fluorescent substance is emitted as the incident light.