Optical Element Marking With Directional Groove Visibility

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Solution Overview

Problem

Existing methods for creating marks on optical elements, such as ophthalmic lenses, often result in marks that are observable during normal use, causing optical distortions and are not permanently visible as intended.

Innovation Solution

A method involving irradiating the optical element's surface with laser radiation to form parallel and aligned elongated grooves, which are then covered with a clear film, allowing the mark to be unobservable when viewed parallel to the grooves' direction and observable when viewed orthogonal to it, due to refractive index differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If physical engraving, chemical leeching, or laser methods are used to introduce a mark into an optical element, then the mark can be made permanent and observable under certain conditions, but the mark becomes visually observable during normal use causing optical distortion

Engineering Contradiction:
Improvepermanency of markVSAvoidoptical distortion
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating grooves with specific dimensional characteristics (depth of 0.1-2 micrometers, width of 10-60 micrometers) and orientation (parallel to optical axis) in specific locations. The grooves are configured to be invisible when viewed from the front surface during normal use, but become observable when viewed from the edge or at specific angles, thus providing different optical properties in different locations and viewing conditions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent resolves the contradiction by transitioning the mark from a two-dimensional surface feature to a three-dimensional subsurface structure. The grooves extend vertically into the optical element parallel to the optical axis, creating a depth dimension that allows the mark to be invisible from the front during normal use but observable from the edge or when the element is tilted, thus adding a vertical dimension to the marking process.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Loss of information

If a mark is made observable under certain conditions, then information can be accessed, but the mark cannot remain unobservable during normal use

Engineering Contradiction:
Improveinformation accessibilityVSAvoidvisual observability during normal use
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the mark's observability conditional rather than static. The grooves are designed to be invisible during normal use but become observable when specific conditions are met (edge viewing, tilting the element, or applying vapor). This dynamic characteristic allows the mark to adapt its visibility based on the viewing conditions, providing information only when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent utilizes optical property changes similar to color changes, where the mark transitions from invisible to visible based on viewing angle and conditions. The grooves create optical effects that make the mark invisible under normal lighting and viewing conditions, but cause it to become observable when viewed from the edge or when vapor is applied, effectively using optical property transformation to control information disclosure.

Inventive Principle:
Principle #32Color changes

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 ensures that the mark is substantially unobservable during normal use while being controllable and observable under specific conditions, enhancing the functionality and usability of optical elements.

Implementation Method 1

irradiating at least a portion of a surface of the optical element with laser radiation, thereby forming a plurality of elongated grooves in the portion of the surface

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

the portion of said surface has a first refractive index, and said clear film has a second refractive index, and a difference between said first refractive index and said second refractive index has an absolute value of from 0.01 to 1.2

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2807517B1Method of producing an optical element having a mark
Publication Date: 2024.03.06 TRANSITIONS OPTICAL INC
  • EP2807517B1 patent drawingFigure 1
  • EP2807517B1 patent drawingFigure 2
  • EP2807517B1 patent drawingFigure 3~4

AI summary

The present invention relates to a method of forming an optical element that includes a mark. The method involves, irradiating at least a portion of a surface of the optical element with laser radiation, thereby forming a plurality of substantially parallel elongated grooves in the portion of the surface, which are each aligned substantially parallel with a common longitudinal direction that extends from a center point of the plurality of elongated grooves. The plurality of elongated grooves together define the mark. A clear film is formed over at least the portion of the surface and the plurality of elongated grooves. Depending on the orientation of a source of electromagnetic radiation as viewed through the optical element relative to the common longitudinal direction of the grooves, the mark is either observable or unobservable. The present invention also relates to an optical element having a mark, as described above.