Undulating Metal Mask Layer for Low-Reflection Microlens Optics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical constructions using metal masks for microlenses suffer from unwanted specular reflection from regions between through openings, leading to inefficiencies and potential curl issues in the optical construction.
Innovation Solution
Employing an undulating metal layer with undulations having a pitch less than the wavelength of visible light, and incorporating an intermediate layer to reduce unwanted reflection and curl, while maintaining a uniform spacing and optical opacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a flat metal mask layer is used in the optical construction, then the structural simplicity is maintained, but unwanted specular reflection occurs from regions between through openings
Solution Approach 1:
The patent applies curvature by transforming the flat metal mask layer into an undulating metal layer with periodic wave-like surface profiles. This curvature modifies the optical interaction by scattering reflected light away from specular directions, thereby reducing harmful reflections while maintaining the metal layer's structural integrity and optical opacity.
Solution Approach 2:
The undulating metal layer introduces local variations in surface geometry while maintaining uniform material composition and thickness. The periodic undulations create localized optical effects that scatter light, while the overall layer retains its function as an opaque mask with defined through openings for the microlenses.
2Reliability
If metal mask layers are used for microlenses, then optical opacity is achieved, but curl issues occur in the optical construction
Solution Approach 1:
The patent modifies the geometric parameters of the metal layer by introducing controlled undulations with specific pitch and amplitude. This parameter change transforms the flat surface into a periodic structure that maintains optical opacity while altering the mechanical stress distribution, thereby preventing curl formation in the optical construction.
3Object-generated harmful factors
If an undulating metal layer is employed to reduce reflection, then harmful reflection is reduced, but the manufacturing complexity increases
Solution Approach 1:
The patent replaces traditional mechanical or chemical methods of reducing reflection (such as anti-reflective coatings or complex multi-layer structures) with a periodic undulating metal layer. This substitution achieves reflection reduction through geometric optics principles, simplifying the manufacturing process while maintaining effectiveness.
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
Substantially reduces unwanted reflection to less than 25% of incident light and minimizes curl, enhancing the performance and stability of the optical construction.
Implementation Method 1
the optical construction reflects less than about 25% of the incident light
Data Source
AI summary
An optical construction includes a lens layer and optically opaque first and second mask layers. The lens layer has a first major surface including a plurality of microlenses arranged along orthogonal first and second directions. The first and second mask layers are spaced apart from the first major surface and define respective pluralities of through first and second openings therein arranged along the first and second directions. The first mask layer is disposed between the structured first major surface and the second mask layer. There is a one-to-one correspondence between the microlenses and the first and second openings. The optical construction includes an intermediate layer disposed between the structured first major surface and the first mask layer and including an undulating second major surface facing, and in substantial registration with, an undulating third major surface of first mask layer so as to define a substantially uniform spacing therebetween.