Piezoelectric Light Scattering Element for Laser Speckle Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image display devices using laser light sources suffer from speckle noise, which degrades image quality, and existing solutions require additional optical elements or driving mechanisms, increasing system size and complexity.
Innovation Solution
A light scattering element with a thin film-like optical element and a piezoelectric element sandwiched between electrodes, which vibrates when an alternating voltage is applied, averaging the speckle pattern to reduce noise without the need for additional lenses or driving mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a light scattering element with a separate driving mechanism is used to vibrate the element for reducing speckle noise, then the speckle noise is reduced, but the device complexity and system size increase
Solution Approach 1:
The patent combines the light scattering element and the piezoelectric actuator into a single integrated structure. The piezoelectric actuator is formed in the same semiconductor substrate as the light scattering element, eliminating the need for separate driving mechanisms and reducing overall device complexity while maintaining the ability to vibrate the scattering element for speckle noise reduction
Solution Approach 2:
The semiconductor substrate serves multiple functions: it acts as the supporting structure for the light scattering element, provides the piezoelectric actuator for vibration, and integrates both optical and mechanical functions in a single component, thereby reducing the number of separate components needed in the system
2Object-affected harmful factors
If additional optical elements or driving mechanisms are added to reduce speckle noise, then the speckle noise is reduced, but the system size increases
Solution Approach 1:
The patent merges the light scattering element and piezoelectric actuator into a single integrated component fabricated on the same semiconductor substrate, eliminating the need for additional separate optical elements or driving mechanisms, thereby reducing the overall system size while maintaining effective speckle noise reduction capability
3Device complexity
If the piezoelectric actuator is integrated with the light scattering element on the same substrate, then the device complexity is reduced, but the driving force may be insufficient
Solution Approach 1:
The patent employs a torsion bar (elastic beam) mechanism that converts the piezoelectric actuator's linear displacement into rotational motion of the mirror. This dynamic mechanical amplification allows a compact piezoelectric actuator to generate sufficient rotational driving force for the mirror despite its small size and integration constraints
Solution Approach 2:
The use of a torsion bar provides mechanical leverage and amplification, where the curved or bent elastic beam structure converts small linear displacements from the piezoelectric actuator into larger rotational movements of the mirror, effectively amplifying the driving force without increasing the actuator size
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 reduces speckle noise by vibrating the light scattering element, improving image quality without increasing the size or complexity of the system, and can be integrated into optical scanning and image projecting devices.
Implementation Method 1
a thin film-like piezoelectric element, which is sandwiched between two electrodes and which is laminated on a surface of the optical element that is different from the scattering surface; wherein a speckle pattern of laser light scattered by the scattering surface and emitted therefrom is averaged by vibration of the piezoelectric element generated when alternating voltage is applied between the two electrodes
Implementation Method 2
a transparent, thin film-like optical element having a scattering surface which scatters incident laser light
Data Source
AI summary
A light scattering element 1 is equipped with a transparent, thin film-like optical element 2 which scatters incident laser light, and a thin film-like piezoelectric element 4, which is sandwiched between two electrodes 3a, 3b and which is laminated on a surface of the optical element 2 that is different from an optical scattering surface 2a. The light scattering element 1 averages a speckle pattern of laser light scatted by the optical scattering surface 2a and emitted therefrom by vibration of the piezoelectric element 4 generated when alternating voltage is applied between the two electrodes 3a, 3b.