Optical Element Coating Identification via Wavelength-Specific Reflectivity

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Solution Overview

Problem

Existing methods fail to reliably distinguish between identical-looking but differently coated optical elements, leading to confusion and logistical errors during lens assembly, particularly in optics production where similar geometric properties mask coating differences.

Innovation Solution

A measuring device with a light source providing multiple light beams of defined wavelengths, focused onto the optical element, and an image sensor to measure reflectivity, determining if the intensity of reflected light exceeds or is below a threshold, allowing differentiation based on wavelength-specific coating suitability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If visual inspection or simple geometric measurement is used to identify optical elements, then the inspection process is simple and fast, but identical-looking elements with different coatings cannot be distinguished

Engineering Contradiction:
Improveinspection simplicityVSAvoidcoating differentiation accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent uses wavelength-specific light beams to interact with the optical element's coating, causing the coating to reflect or transmit light in a manner that reveals its wavelength-specific properties. The image sensor detects these optical responses, enabling differentiation between coatings that appear identical visually but have different wavelength characteristics.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent changes the wavelength parameter of the light beam to match the specific wavelength for which the optical element is coated. By comparing the optical response at the coated wavelength versus other wavelengths, the system can identify whether the element has the correct coating, thus differentiating between identical-looking elements with different coatings.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If multiple wavelength-specific light beams and evaluation components are added to distinguish coatings, then coating differentiation accuracy improves, but device complexity increases

Engineering Contradiction:
Improvecoating differentiation accuracyVSAvoidmeasuring device structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses a single image sensor that can detect multiple wavelengths by analyzing the intensity of reflected or transmitted light at different wavelengths. The evaluation device processes the optical responses to determine both the presence of coating and the specific wavelength for which the element is coated, allowing one component to perform multiple measurement functions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces an evaluation device as an intermediary that receives optical responses from the image sensor and automatically determines whether the optical element has the correct coating. This intermediary processes the raw optical data and provides clear identification results, simplifying the overall system while maintaining high measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If thorough coating verification is performed to prevent assembly errors, then assembly reliability improves, but inspection time increases

Engineering Contradiction:
Improveassembly correctnessVSAvoidinspection duration
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent uses periodic or sequential illumination with different wavelength-specific light beams, where the light source emits light at specific wavelengths in sequence and the image sensor captures the optical response at each wavelength. This periodic measurement approach allows rapid verification of coating properties without requiring continuous or prolonged inspection.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent performs coating verification as a preliminary step before final assembly, using quick wavelength-specific optical measurements to identify and separate correctly coated elements from incorrectly coated ones. By conducting this verification early in the process, the system prevents assembly errors before they occur, maintaining high reliability while minimizing total inspection time.

Inventive Principle:
Principle #10Preliminary action

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

Enables quick and cost-effective identification of the correct coating for optical elements, reducing assembly errors and follow-up costs by distinguishing between coatings through simple, inexpensive components and a few seconds of testing time.

Implementation Method 1

an image sensor to sense at least one intensity of the light beams reflected by the optical element

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4165394B1Measuring device and method for measuring a reflectivity of coated optical elements
Publication Date: 2023.11.01 TRIOPTICS GMBH
  • EP4165394B1 patent drawingFigure 1
  • EP4165394B1 patent drawingFigure 2
  • EP4165394B1 patent drawingFigure 3

AI summary

The invention relates to a measuring device (100) for measuring a reflectivity of a coated optical element (105) for an objective lens. The measuring device (100) has a light providing unit (107), at least one measuring device objective lens (110) and at least one image sensor (115). The light providing unit (107) has at least one light source (117) which is designed to provide at least two light beams (120), each of which has a different defined wavelength. The measuring device objective lens (110) is formed to focus the light beams (120) onto the coated optical element (105). The image sensor (115) is arranged and designed to sense at least an intensity and/or reflection wavelength of the light beams (125) reflected from the optical element (105) in order to measure the reflectivity in response to the sensed intensity and/or reflection wavelength of the light beams (125) reflected from the optical element (105).