Light Emitting Apparatus for Projector Speckle Noise Reduction
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Solution Overview
Problem
Semiconductor lasers with high coherency, used as light sources in projectors, produce speckle noise due to their coherent light emission, which is not effectively reduced by existing technologies.
Innovation Solution
A light emitting apparatus comprising multiple light emitters with different resonance wavelengths, arranged in specific lattice structures to couple light in phase, reducing coherency and speckle noise while maintaining a small radiation angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a semiconductor laser with high coherency is used as a light source, then high luminance and small radiation angle are achieved, but speckle noise is generated
Solution Approach 1:
The invention divides a single high-coherency laser source into multiple independent laser devices arranged in an array. Each device emits laser beams with slightly different wavelengths, and by controlling the phase relationships between these segmented sources, the patent achieves both high luminance through constructive interference and speckle noise reduction through wavelength diversity
Solution Approach 2:
The patent applies local quality by giving each laser device in the array a slightly different resonance wavelength while maintaining specific spatial arrangements. This local variation in wavelength properties allows the system to reduce speckle noise through wavelength diversity while preserving the high luminance and small radiation angle characteristics through controlled phase relationships
2Object-generated harmful factors
If multiple laser devices with different wavelengths are arranged in an array to reduce speckle noise, then coherency is lowered, but radiation angle increases
Solution Approach 1:
The patent employs dynamics by controlling the phase relationships between laser devices dynamically. By adjusting the relative phases of laser beams from devices with different wavelengths, the system can steer and focus the combined beam to maintain a small radiation angle while preserving the wavelength diversity needed for speckle noise reduction
Solution Approach 2:
The patent adds the dimension of phase control to the spatial arrangement of laser devices. By controlling both the spatial positions and the phases of multiple wavelength-differentiated sources, the system achieves constructive interference in specific directions (maintaining small radiation angle) while utilizing wavelength diversity (reducing speckle noise)
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 apparatus effectively reduces speckle noise and achieves a small radiation angle, suitable for projector applications by ensuring the light emitters are in phase and have distinct resonance wavelengths, enhancing the projector's performance.
Implementation Method 1
a plurality of first light emitters E1 and a plurality of second light emitters E2, which differ from the first light emitters E1 in terms of resonance wavelength
Implementation Method 2
a semiconductor laser using nano-columns is expected to achieve high-power light emission at a small radiation angle based on a nano-column photonic crystal effect
Data Source
AI summary
A light emitting apparatus including a plurality of first light emitters and a plurality of second light emitters that differ from the first light emitters in terms of resonance wavelength, in which the second light emitters are each disposed between each adjacent pair of the first light emitters, first light that resonates in the plurality of first light emitters is in phase, and second light that resonates in the plurality of second light emitters is in phase.