Laser Source Assembly Polarization Adjustment Speckle Reduction
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Solution Overview
Problem
Projection apparatuses experience a significant speckle phenomenon due to strong coherence of laser beams, leading to poor display effects in projection images.
Innovation Solution
A laser source assembly is designed with a polarization direction adjustment component that adjusts the polarization direction of laser beams, reducing coherence by ensuring different polarization directions for portions of the same color laser beams, thereby reducing speckle and improving image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If laser beams with strong coherence are used for projection, then the projection apparatus can achieve high brightness and clear images, but the speckle phenomenon occurs significantly degrading the display effect
Solution Approach 1:
The patent segments the laser beam by dividing it into multiple sub-beams with different polarization directions. The polarization direction adjustment component (such as a half-wave plate or liquid crystal variable retarder) splits the original coherent laser beam into multiple beams with different polarization states, which then interfere with each other to reduce the speckle phenomenon while maintaining projection brightness.
Solution Approach 2:
The patent changes the polarization parameter of the laser beam by using a polarization direction adjustment component. This component adjusts the polarization direction of different portions of the laser beam, creating a distribution of polarization angles that reduces coherence-induced speckle while preserving the overall intensity and projection quality.
2Object-affected harmful factors
If the polarization direction of laser beams is adjusted to reduce coherence, then the speckle phenomenon is reduced, but the complexity of the laser source assembly increases
Solution Approach 1:
The polarization direction adjustment component serves multiple functions: it adjusts the polarization direction of laser beams, controls the distribution of polarization angles, and reduces speckle phenomenon. By integrating these functions into a single component, the patent minimizes the increase in device complexity while achieving the desired reduction in coherence effects.
Solution Approach 2:
The patent uses adjustable polarization components (such as liquid crystal variable retarders or half-wave plates) that can be controlled electronically to change polarization parameters. This allows for dynamic adjustment of the polarization distribution without requiring complex mechanical structures, thereby reducing the overall complexity of the laser source assembly.
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 effectively minimizes the speckle phenomenon, enhancing the display effect of projection images by reducing laser beam coherence and improving the uniformity of the combined laser beams.
Implementation Method 1
The at least one polarization direction adjustment component is configured to adjust a polarization direction of at least a portion of the laser beams of the plurality of colors, so as to obtain a target laser beam. A laser beam of at least one color in the target laser beam satisfies that a polarization direction of a portion of the laser beam of a same color is different from a polarization direction of another portion of the laser beam of the same color.
Data Source
AI summary
A laser source assembly and a projection apparatus are provided. The laser source assembly includes a laser device, a combining lens group, and a polarization direction adjustment component. The laser device is configured to emit laser beams of a plurality of colors. The combining lens group is configured to combine the laser beams of the plurality of colors and propagate the combined laser beams in a first direction. The polarization direction adjustment component is configured to adjust a polarization direction of at least a portion of the laser beams of the plurality of colors to obtain a target laser beam. A laser beam of at least one color in the target laser beam satisfies that the polarization direction of a portion of the laser beam of a same color is different from the polarization direction of another portion of the laser beam of a same color.