Optical Imaging Lens Coating for Wide-Angle Reflection Control
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Solution Overview
Problem
Conventional anti-reflective coating techniques fail to effectively reduce reflections across a wide field of wavelengths, especially at large angles, and lack sufficient anti-oxidation properties, particularly in optical systems with complex surface shapes, leading to reduced image quality and inadequate protection against moisture and oxygen.
Innovation Solution
An optical imaging lens assembly featuring a high-low refractive coating with alternating layers of high and low refractive coating layers, combined with a gradient refractive coating containing holes, and a gradient refractive index, which is made of metal oxide, providing a porous structure to enhance anti-reflectivity and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional anti-reflective coating techniques are used, then the coating process is simple, but the anti-reflectivity is insufficient especially at large angles and long wavelengths
Solution Approach 1:
The anti-reflective coating is divided into multiple functional layers: a gradient refractive index coating layer with continuously varying refractive index, and a high-low refractive index multilayer coating system with alternating high and low refractive index layers. Each layer serves specific optical functions to collectively reduce reflections across wide wavelength ranges and large angles.
Solution Approach 2:
The gradient refractive index coating layer features a refractive index that changes continuously from the substrate surface outward, creating an optimized optical path. The high-low refractive index layers use materials with specifically selected refractive indices to achieve destructive interference of reflected light waves across different wavelengths and angles.
2Manufacturing precision
If glass materials with small dispersion are used, then image quality improves, but anti-oxidation ability against moisture and oxygen deteriorates
Solution Approach 1:
The coating system combines multiple materials with complementary properties: the gradient refractive index layer uses metal oxides with controlled porosity for optical performance, while the high-low refractive index layers use materials like aluminum oxide and other metal oxides that provide both optical functionality and chemical resistance. This composite structure achieves both image quality and durability.
3Ease of manufacture
If conventional coating techniques are used on lens elements with extreme surface shape changes, then the coating application is straightforward, but the uniformity and anti-reflectivity requirements for high-end optical systems cannot be satisfied
Solution Approach 1:
The gradient refractive index coating layer is designed with spatially varying properties, where the refractive index changes continuously from the substrate surface outward. This local variation in optical properties allows the coating to adapt to different incident angles and wavelengths across the lens surface, achieving uniform anti-reflective performance even on complex surfaces.
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 reflections across a wide wavelength range, improves image quality, and enhances the anti-oxidation and anti-corrosion properties of optical lens elements, especially in high-end systems with complex surface shapes.
Implementation Method 1
the high-low refractive coating includes at least one high refractive coating layer and at least one low refractive coating layer, the high refractive coating layer and the low refractive coating layer are stacked in alternations
Implementation Method 2
the gradient refractive coating includes a plurality of holes, the holes away from the optical lens element including the anti-reflective coating are relatively larger than the holes close to the optical lens element including the anti-reflective coating
Implementation Method 3
the gradient refractive coating is mainly made of metal oxide... providing a porous structure to enhance anti-reflectivity
Implementation Method 4
When the incident angle increases, the difference of track lengths of the incident light between the coating layers is insufficient to achieve the conditions for destructive interference
Data Source
AI summary
An optical imaging lens assembly includes at least one optical lens element. The optical lens element includes an anti-reflective coating, and the anti-reflective coating is arranged on at least one surface of the optical lens element. The anti-reflective coating includes a high-low refractive coating and a gradient refractive coating, and the high-low refractive coating is arranged between the optical lens element and the gradient refractive coating. The high-low refractive coating includes at least one high refractive coating layer and at least one low refractive coating layer, which are stacked in alternations. The low refractive coating layer is in contact with the optical lens element. The gradient refractive coating includes a plurality of holes, and the holes away from the optical lens element are relatively larger than the holes close to the optical lens element.