Speckle Reduction Using Vibration Lenslet Integrator
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Solution Overview
Problem
Current methods for reducing speckle in laser-based projection systems often require expensive moving parts, decrease brightness, or compromise reliability, as they attempt to address the high-frequency intensity variations caused by partial coherence in laser light.
Innovation Solution
A lenslet integrator system that includes a first lenslet array with motion, such as vibration, to average multiple speckle patterns, combined with a second lenslet array and an output lens to achieve spatial uniformity and speckle reduction, using mechanical, electrical, or piezoelectric transducers to impart motion that matches the resonance frequency and exceeds the optical wavelength velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional speckle reduction methods are used, then speckle is reduced, but system cost increases due to expensive moving parts
Solution Approach 1:
The patent applies the Dynamics principle by introducing motion to the lenslet array to dynamically average multiple speckle patterns. The lenslet array is vibrated at resonance frequency, creating temporal variation in the speckle pattern that averages out the high-frequency intensity variations. This dynamic approach reduces speckle without requiring complex mechanical moving parts in the traditional sense, as the motion is imparted through resonance excitation of the existing lenslet array structure.
Solution Approach 2:
The patent directly applies Mechanical vibration by vibrating the lenslet array at its resonance frequency to reduce speckle. The vibration causes the lenslet array to move back and forth, creating multiple slightly different speckle patterns that average out over time. This vibration-based approach provides an economical solution compared to conventional methods that require expensive mechanical moving parts, as it utilizes the natural resonance of the lenslet array structure itself.
2Object-affected harmful factors
If conventional speckle reduction methods are used, then speckle is reduced, but brightness decreases
Solution Approach 1:
The Dynamics principle is applied by vibrating the lenslet array to create temporal averaging of speckle patterns while maintaining spatial coherence. This dynamic motion allows the system to reduce speckle without sacrificing brightness, as the vibration occurs rapidly enough to average out speckle but maintains the overall light throughput and illumination intensity.
Solution Approach 2:
The patent appliesParameter changes by adjusting the vibration frequency and amplitude of the lenslet array to optimize speckle reduction while maintaining brightness. By tuning the vibration parameters to match the resonance frequency of the lenslet array, the system achieves effective speckle averaging without losing light throughput, thus maintaining illumination intensity.
3Object-affected harmful factors
If conventional speckle reduction methods are used, then speckle is reduced, but reliability is compromised
Solution Approach 1:
The Mechanical vibration principle is applied by exciting the lenslet array at its resonance frequency, which is an inherent property of the existing structure. This approach improves reliability compared to conventional methods because it does not require additional mechanical moving parts that could fail. The vibration is imparted through the existing lenslet array structure, utilizing its natural resonance characteristics, thereby reducing the introduction of new potential failure points.
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 system effectively reduces speckle by averaging multiple patterns, providing both spatial uniformity and speckle reduction while maintaining optical throughput and system reliability, with the potential for integration with other techniques to enhance performance.
Implementation Method 1
the first lenslet array has motion sufficient to reduce speckle by averaging multiple speckle patterns across its array
Implementation Method 2
the motion of the first lenslet array may be substantially equal to a resonance frequency of a structure holding the first lenslet array
Implementation Method 3
a second lenslet array configured to receive light that is roughly focused from the moving first lenslet array
Implementation Method 4
an output lens configured to receive light focused from the second lenslet array
Data Source
AI summary
Disclosed herein are techniques for the reduction speckle of a projection display system using novel lenslet integrators and related methods. In one embodiment, a lenslet integrator system for reducing speckle on a display screen may comprise a first lenslet array configured to receive incoming light for use in displaying an image on a display screen. Specifically, the first lenslet array has motion sufficient to reduce speckle by averaging multiple speckle patterns across its array. Such an exemplary system may also include a second lenslet array configured to receive light that is roughly focused from the moving first lenslet array, due to the motion of the first array. In addition, such systems may also include an output lens configured to receive light focused from the second lenslet array for output from the system for illumination of the display screen.