Laser Light Source System Speckle Reduction via Segmented Scattering
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Solution Overview
Problem
The application of laser diodes in projection and display is hindered by the speckle phenomenon, and existing methods to eliminate speckle either increase costs or reduce light efficiency, often requiring additional laser diodes and complex light source designs.
Innovation Solution
A light source system that includes a laser diode array, a light splitting and combining assembly, a scattering assembly with two separately positioned scattering elements, and a light homogenizing element, which scatters and homogenizes the combined light beam to eliminate speckle while maintaining light efficiency and reducing system volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a scattering sheet is added between the light source and lens to eliminate speckle, then speckle is eliminated, but light efficiency is reduced due to large amount of light reflected back toward the light source
Solution Approach 1:
The patent divides the scattering function into multiple separate scattering elements positioned at different locations in the optical path, rather than using a single scattering sheet. This segmentation allows light to be scattered multiple times in different directions, reducing the amount of light reflected back toward the light source while maintaining speckle elimination effectiveness.
Solution Approach 2:
The patent introduces a light homogenizing element as an intermediary component between the scattering elements and the lens. This homogenizing element further processes the scattered light to improve uniformity and reduce harmful reflections, acting as a mediator that optimizes the interaction between scattered light and the subsequent optical components.
2Object-affected harmful factors
If a scattering element is added for each laser diode to eliminate speckle, then speckle is eliminated, but device complexity increases
Solution Approach 1:
The patent merges the speckle elimination function for multiple laser diodes into a single scattering assembly that processes the combined light beam from all laser diodes. Instead of having separate scattering elements for each laser diode, the system combines the light from multiple sources and applies scattering once to the combined beam, significantly reducing design complexity while maintaining effective speckle elimination.
Solution Approach 2:
The scattering assembly is designed to handle the combined light beam from multiple laser diodes with different colors or wavelengths, making it a universal solution that works for all laser diodes in the array. This multi-functional approach eliminates the need for individualized scattering elements for each laser diode, simplifying the overall system design.
3Illumination intensity
If more laser diodes are added to achieve the same brightness after scattering, then brightness is maintained, but system volume increases
Solution Approach 1:
The patent performs light combining before the scattering process, so that the light from multiple laser diodes is already consolidated into a single combined beam when it reaches the scattering assembly. This preliminary combining action allows the system to maintain brightness efficiency without requiring additional laser diodes, as the scattering process is applied to the already-combined light rather than to individual diode beams separately.
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 speckle while ensuring high light efficiency and reducing the volume of the light source system, compared to traditional methods that require a scattering element for each laser diode.
Implementation Method 1
The scattering assembly is configured to scatter and homogenize the combined light beam
Implementation Method 2
The light homogenizing element is configured for homogenizing light beam incident to the light homogenizing element
Data Source
AI summary
A light source system includes a light source, a light splitting and combining assembly, a scattering assembly, and a light homogenizing element. The light source is configured for generating laser light which includes a first color light and a second color light. The light splitting and combining assembly is configured to combine the laser light to form a combined light beam. The scattering assembly is configured to scatter and homogenize the combined light beam. The scattering assembly includes a first scattering element and a second scattering element, and the first scattering element and the second scattering element are separately positioned. The light homogenizing element is located between the scattering assembly and the light splitting and combining assembly or behind the scattering assembly or between the first scattering element and the second scattering element.