Microlens Coating Molding for Optical Power Preservation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing optical articles with microlenses suffer from a reduction in optical power when covered with an abrasion-resistant coating due to surface deformations, and reducing coating thickness compromises scratch protection.

Innovation Solution

A method involving molding an abrasion-resistant coating over a base lens substrate with microlenses, ensuring the coating encapsulates each microlens and maintains the same base curve as the substrate, thereby preserving the optical power and enhancing scratch protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If an abrasion-resistant coating is applied over microlenses, then scratch protection is improved, but optical power is reduced

Engineering Contradiction:

Improvescratch protectionVSAvoidoptical power

Core Design Contradiction:

StrengthVSPower

Solution Approach 1:

The microlenses are pre-formed on the base lens substrate before applying the abrasion-resistant coating. The coating is then molded to precisely replicate the microlens geometry, ensuring the optical elements are established before protection is added without compromising their function.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention changes the coating thickness parameter locally - the coating is made thinner at the microlens protrusions (where it encapsulates the lens) and thicker at the base surface. This parameter variation allows the coating to provide scratch protection while maintaining the optical power of the microlenses by minimizing interference with light passage through the lens structures.

Inventive Principle:

Principle #35Parameter changes

2Power

If coating thickness is reduced to preserve optical power, then optical power is maintained, but scratch protection is compromised

Engineering Contradiction:

Improveoptical powerVSAvoidscratch protection

Core Design Contradiction:

PowerVSStrength

Solution Approach 1:

The abrasion-resistant coating is designed with non-uniform thickness - locally thinner at the microlens protrusions to preserve optical power and locally thicker at the base surface to maximize scratch protection. This local quality variation allows simultaneous optimization of both optical performance and mechanical protection.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention moves from a uniform coating thickness approach to a three-dimensional coating profile that varies in thickness across different spatial locations. By utilizing the vertical dimension (thickness variation from base to microlens tip), the coating can provide adequate protection at the base while being sufficiently thin at the microlens structures to maintain optical power.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Strength

If microlenses are covered with abrasion-resistant coating, then scratch protection is improved, but surface curvature is altered

Engineering Contradiction:

Improvescratch protectionVSAvoidsurface curvature

Core Design Contradiction:

StrengthVSShape

Solution Approach 1:

The microlens geometry is pre-established on the substrate before coating application. The coating molding process then uses this pre-formed geometry as a master, ensuring the coating surface curvature matches the microlens shape rather than flattening or deforming it.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention maintains the spherical or aspherical curvature of the microlenses by molding the coating to conform to the pre-formed lens shapes. The coating is designed to follow the curved surface profile of the microlenses rather than imposing a flat or different curvature, preserving the optical surface quality.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 maintains the optical power of microlenses while providing enhanced scratch protection by ensuring the abrasion-resistant coating encapsulates each microlens without altering its shape or power, addressing the limitations of prior art.

Implementation Method 1

filling the volume with a moldable material suitable for forming abrasion resistant coating; and setting the moldable material to form an abrasion-resistant coating over the base lens substrate

Methodology Applied

Scientific EffectMolding:

Implementation Method 2

the abrasion-resistant coating encapsulates each microlens

Methodology Applied

Scientific EffectEncapsulation: Physical Containment

Data Source

PatentEP3896499B1Improved method for forming an optical article comprising microlenses

Publication Date: 2023.11.29 ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D OPTIQUE)

Figure 1a~2b
Figure 3a~3e

AI summary

It is disclosed a method of forming an optical article comprising: providing a base lens substrate (10) having opposite first and second optical surfaces, and at least one microlens protruding from the second optical surface, placing the base lens substrate in a mold (90) comprising first (91) and second (92) mold portions such that the first optical surface is disposed on a molding surface of the first mold portion (91), and that a volume is defined between a molding surface of the second mold portion and the second optical surface, filling the volume with a moldable material suitable for forming abrasion resistant coating; and setting the moldable material to form an abrasion-resistant coating (20) over the base lens substrate (10), wherein the abrasion resistant coating encapsulates each microlens (30).