Toric Lens Antireflection via Two-Stage Hole Pattern
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Solution Overview
Problem
Existing optical components with fine uneven structures for antireflection require high temperature and pressure in injection molding, leading to shape deformation and degraded optical performance due to high aspect ratios.
Innovation Solution
A toric lens with a fine uneven structure featuring a two-stage hole pattern, including a cylindrical shape and a circular truncated cone shape, is manufactured using injection molding with controlled stress relaxation to maintain shape accuracy and reduce reflectance, employing a method that involves forming a NiP plating film, SiO2 film, and photoresist patterns to achieve an optimal aspect ratio and pitch interval for antireflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a fine uneven structure with high aspect ratio is used to reduce reflectance, then antireflection performance is improved, but shape deformation increases during injection molding
Solution Approach 1:
The invention changes the aspect ratio parameter of the fine uneven structure from high to low (0.2 to 0.8 range), and modifies the shape from circular truncated cone to two-stage structure with cylindrical and conical portions. This parameter change allows achieving antireflection performance while avoiding shape deformation during injection molding, as the lower aspect ratio structure is more stable under molding stress.
2Ease of manufacture
If high temperature and pressure are applied during injection molding to form high aspect ratio structures, then fine uneven structure formation is improved, but optical performance degrades
Solution Approach 1:
The invention changes the aspect ratio parameter to a lower range (0.2-0.8), which allows the fine uneven structure to be formed under normal injection molding conditions without requiring extreme temperature and pressure. This parameter modification maintains both manufacturability and optical performance by avoiding the shape deformation that occurs under harsh molding conditions.
3Object-affected harmful factors
If a circular truncated cone shape is used for the fine uneven structure, then antireflection effect is achieved, but manufacturing complexity increases
Solution Approach 1:
The invention segments the fine uneven structure into two distinct stages: a cylindrical portion at the bottom and a conical portion at the top. This segmentation allows each portion to serve a specific function - the cylindrical portion provides structural stability during molding, while the conical portion contributes to the antireflection effect. The two-stage structure simplifies manufacturing compared to a single high aspect ratio conical structure.
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 method results in an optical element with improved antireflection performance and reduced manufacturing costs, while maintaining shape accuracy and reducing reflectance, even at lower aspect ratios, thereby enhancing the optical performance and cost-effectiveness of the toric lens.
Implementation Method 1
An optical component having a fine uneven structure with a period smaller than a wavelength of light expresses an antireflection structure
Implementation Method 2
the fine uneven structure is formed by injection molding
Implementation Method 3
forming a NiP plating film
Implementation Method 4
forming a NiP plating film, SiO2 film
Data Source
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AI summary
In a toric lens comprising a toric surface having a fine uneven structure, the fine uneven structure includes a plurality of holes, the plurality of holes has a hole depth H and a surface opening diameter ϕt which satisfy an expression of 0.3 ≤ H/ϕt ≤ 0.6, and (a) the plurality of holes has a cylindrical shape proximal to a bottom surface and a circular truncated cone shape distal to the bottom surface, the circularly truncated cone shape having a diameter gradually increasing toward a top surface of the toric surface, or (b) an angle θ between the top surface of the toric surface and a side surface of the plurality of holes satisfies 78° ≤ θ ≤ 85°.