LED Module Optical Inspection via Waveguide Intermediary

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current diagnostic methods for LED light modules primarily assess electrical functionality, failing to detect optical errors, and existing solutions for evaluating optical function are costly and limited in diagnostic capability.

Innovation Solution

A method using optical waveguides to connect LEDs within a module, allowing one LED to serve as a light source and the other as a photodetector, with a measuring device to assess the luminous flux, and reversing the energization and measurement to identify defective modules.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If electrical parameter measurement is used for LED diagnosis, then the diagnostic method is simple and low-cost, but optical errors cannot be detected

Engineering Contradiction:
Improvediagnostic method simplicityVSAvoiderror detection capability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

An optical waveguide is introduced as an intermediary component to transmit light between LEDs. The waveguide enables optical signal transmission from a driven LED to a measuring LED, allowing optical functionality detection without requiring complex external optical equipment, thus maintaining simplicity while enabling optical error detection

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The LED modules themselves are used to generate and detect optical signals. One LED in the pair serves as the light source while the other acts as the detector, allowing the system to self-diagnose optical functionality using its own components rather than requiring separate external testing equipment

Inventive Principle:
Principle #25Self-service

2Reliability

If optical inspection systems with photodetectors or cameras are used, then optical functionality can be evaluated, but acquisition costs are high and diagnostic options are limited

Engineering Contradiction:
Improveoptical function evaluation capabilityVSAvoidsystem cost and complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of using expensive external optical sensors or cameras, the invention uses LEDs themselves to generate and detect optical signals. The optical waveguide transmits the light signal, creating a simplified copy of the optical path that can be measured electrically, thereby avoiding the need for costly optical inspection equipment while maintaining diagnostic capability

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The invention replaces complex mechanical/optical inspection systems (photodetectors, cameras) with an electrical measurement system. By converting the optical detection function into an electrical measurement through the waveguide-transmitted light signal, the system achieves optical functionality evaluation using simpler electrical components

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 reliable and cost-effective testing of LED modules by evaluating their optical functionality, increasing error detection rates while maintaining low component costs.

Implementation Method 1

the two LEDs of a pair are optically connected to one another via an optical waveguide

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

one of the two LEDs of the pair is selected and connected to at least one power source

Methodology Applied
Scientific EffectLight emitting diode effect: Light Emitting Diode

Implementation Method 3

the physical change generated in the other of the two LEDs is measured

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3414581B1Method and ict device for inspecting modules of a lighting device, said lighting device containing at least two leds
Publication Date: 2020.01.01 ZKW GRP GMBH
  • EP3414581B1 patent drawingFigure 1~2
  • EP3414581B1 patent drawingFigure 3~4a
  • EP3414581B1 patent drawingFigure 5~6a

AI summary

The invention relates to a method for inspecting LED modules (1) of a lighting device, said lighting device containing at least two LEDs (2-1...2-4), wherein at least one pair (2-1, 2-2; 2-3, 2-4) of LEDs of a module (1) is selected, the two LEDs of said pair are connected to each other optically, preferably via a light conductor (7-1, 7-2), one (2-2; 2-4) of the two LEDs of the pair is connected to at least one power source (11-1; 11-2) and the other (2-1; 2-3) of the two LEDs is connected to at least one electrical measurement device (12-1; 12-2), one of the two LEDs is energized with a specified current strength and the physical change generated in the other of the two LEDs is measured, and then the energizing and measuring on the two LEDs of the pair are switched and the module is identified as faulty if the value identified by the measurement device lies outside of a specifiable range in at least one measurement. In an ICT device for carrying out the method according to the invention, an ICT adapter means (5) has at least one fiber optic cable (7) for the optical connection of two LEDs (2-1, 2-2; 2-3, 2-4).