Laser Projector Polarization Alignment for Color Aberration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Laser projection systems suffer from local color aberration phenomena such as 'color speckle' and 'color patch' due to differences in polarization directions of red, blue, and green laser light, leading to poor image quality.
Innovation Solution
A laser projector design that includes a laser assembly with red, blue, and green laser light emitting regions, where the polarization directions are adjusted using phase delaying components like half-wave plates to align with the polarization direction of red laser light, ensuring all laser light is either P-polarized or S-polarized, and a beam combination mirror group to combine and homogenize the light, reducing differences in transmittance and reflectivity across the projection screen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If three-color laser light sources with different polarization directions are used for projection imaging, then the brightness and monochromaticity are improved, but local color aberration phenomena such as color speckle and color patch occur
Solution Approach 1:
The patent changes the polarization state parameter of the laser light by introducing wave plates (half-wave plates or quarter-wave plates) in the optical path. These wave plates transform the linearly polarized light from different polarization directions into circularly polarized light or uniformly polarized light, thereby eliminating the color aberration caused by different polarization directions while maintaining the brightness and monochromaticity benefits of laser light sources
Solution Approach 2:
The patent introduces wave plates as intermediary optical components between the laser light sources and the projection screen. These wave plates act as mediators that transform the polarization state of the light, converting light with different polarization directions into light with uniform polarization characteristics, thus eliminating color speckle and color patch phenomena
2Productivity
If laser light with different polarization directions is used, then the light emission efficiency is improved, but the transmittance and reflectivity uniformity across the projection screen deteriorates
Solution Approach 1:
The patent changes the polarization parameter of the laser light using wave plates to ensure uniform polarization state across all color channels. This parameter transformation maintains the high light emission efficiency of lasers while ensuring uniform transmittance and reflectivity characteristics across the projection screen by eliminating polarization-direction-dependent variations
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 solution effectively eliminates local color aberration, improving the uniformity and brightness of the projected image by ensuring consistent light processing across different polarization directions, thereby enhancing the overall image quality.
Implementation Method 1
a phase delaying component, on a light emitting path of at least one of the red laser light, the blue laser light or the green laser light, and configured to change a polarization direction of the at least one of the red laser light, the blue laser light or the green laser light
Implementation Method 2
a beam combination mirror group configured to combine the red laser light, the blue laser light and the green laser light emitted by the laser assembly
Data Source
AI summary
A laser projector includes a laser assembly, a beam combination mirror group and a phase delaying component. The laser assembly includes a red laser light emitting region, a blue laser light emitting region and a green laser light emitting region. Red laser light is polarized in a first direction, green laser light is polarized in a second direction, and blue laser light is polarized in a third direction. The beam combination mirror group combines the red laser light, the blue laser light and the green laser light. The phase delaying component is on a light emitting path of at least one of the red laser light, the blue laser light the green laser light, and changes a polarization direction of the at least one of the red laser light, the blue laser light or the green laser light before being output by the beam combination mirror group.