Optical Component Additive Manufacturing with Coating-Based Surface Smoothing
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Solution Overview
Problem
Additive manufacturing of ophthalmic lenses results in a stepped pattern due to the deposition of predetermined volumes of material, leading to high roughness and an unacceptable surface for optical applications.
Innovation Solution
A method involving additive manufacturing to create an unfinished surface with a relief pattern, followed by applying and hardening a layer of hardenable coating liquid to fill depressions and smooth the surface, promoting improved wetting and adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If additive manufacturing is used to manufacture optical elements, then manufacturing precision and productivity are improved, but surface roughness increases due to stepped pattern
Solution Approach 1:
The patent applies preliminary action by creating an unfinished surface with controlled relief pattern during the additive manufacturing process, then subsequently applying a coating layer to smooth the surface. This two-stage approach allows the manufacturing process to maintain high productivity while achieving the required surface smoothness for optical applications.
Solution Approach 2:
The patent uses a coating layer as an intermediary substance that fills the depressions and smooths the stepped pattern created by additive manufacturing. This intermediate coating transforms the rough manufactured surface into a smooth optical surface without requiring complex post-processing mechanical operations.
2Manufacturing precision
If a film or membrane is used to spread resin to smooth the surface, then surface smoothness is improved, but the optical element may deform or the resin may not spread homogeneously
Solution Approach 1:
The patent changes the physical and chemical parameters of the coating material and application conditions to ensure homogeneous spreading. By controlling the viscosity, surface tension, and curing characteristics of the coating layer, the patent achieves uniform resin distribution without deformation or incomplete coverage.
Solution Approach 2:
The patent replaces mechanical spreading methods with a chemical curing process. The coating layer is applied in a liquid state and then cured to form a smooth surface, eliminating the need for mechanical spreading pressure that could cause deformation or non-homogeneous distribution.
3Manufacturing precision
If the coating liquid is applied to fill depressions, then surface smoothness is improved, but air inclusions may be formed
Solution Approach 1:
The patent uses hydraulic principles by applying the coating liquid in a liquid state that flows into and fills the depressions of the relief pattern. The liquid state allows complete penetration into depressions without trapping air, and the subsequent curing locks in the smooth surface without air inclusions.
Solution Approach 2:
The patent performs preliminary action by applying the coating layer before the additive manufacturing is completely finished, while the surface is still in an unfinished state. This timing allows the coating to fill depressions effectively and bond to the unfinished surface, preventing air inclusion formation.
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 effectively smooths the external surface of optical elements, enhancing their ability to meet desired optical functions by reducing the stepped pattern and improving surface roughness.
Implementation Method 1
The coating liquid hardens with the unfinished part of the unfinished surface thereby improving adhesion
Implementation Method 2
the improved wettability enables to use a coating liquid with self-leveling properties that can smooth said depressions of the relief pattern
Implementation Method 3
the spreading of the hardenable material over the unfinished surface is improved as compared to spreading over a finished or hardened surface due to improved wetting properties
Implementation Method 4
applying and spreading said unfinished surface with a layer of hardenable coating liquid configured to at least partially fill the at least one depression; hardening the layer of hardenable coating liquid
Data Source
AI summary
A method of manufacturing an optical component having at least one optical function, comprising: —manufacturing using an additive manufacturing process at least part of an optical element (40) by depositing a plurality of predetermined volume elements (14) of polymerizable material, a part of the optical element (40) being configured to provide at least a part of the optical function of an optical component, said additively manufacturing being performed such that the optical element (40) comprises an unfinished peripheric surface (42), said unfinished peripheric surface (42) having a relief pattern (44) formed by traces of the additive manufacturing process and having at least one depression (18) with regard to another part of the peripheric surface (42), —coating said unfinished peripheric surface (42) with a layer (50) of coating liquid (46) configured to at least partially fill the at least one depression (18).