Peripheral Micro-LED Illumination for Dental Shade Measurement

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Solution Overview

Problem

Current lighting devices for tooth shade-taking devices face issues with light power loss during guidance, uneven light distribution, and thermal management, particularly with LED lighting, which affects the precision and reproducibility of shade measurement.

Innovation Solution

The solution involves a lighting device with micro-LEDs arranged peripherally on a ring around a lens, coupled with reflective insulation and a polarizing film to ensure even illumination and minimize thermal effects, using a specific refractive index material for the light guide to maintain light quality and reduce manufacturing complexities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If light is guided through a hollow body to reach the measurement point, then the light can be delivered to the distal end, but power loss occurs during light guidance due to transmission coefficient limitations

Engineering Contradiction:
Improvelight powerVSAvoidpower loss during guidance
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The patent replaces the mechanical/optical waveguide system with a direct LED placement system. Instead of guiding light through a hollow body where transmission losses occur, LEDs are positioned directly at the measurement point to eliminate the light guidance path and associated power losses.

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

Solution Approach 2:

The patent introduces a diffuser as an intermediary element between the LED light source and the measurement point. The diffuser distributes the light from the LED uniformly across the measurement area, achieving both high illumination intensity and uniform light distribution without the power losses associated with waveguide transmission.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If image acquisition means are placed in the light beam path, then color measurement can be performed, but the emitting surface area at the exit of the hollow body is reduced

Engineering Contradiction:
Improvecolor measurement capabilityVSAvoidemitting surface area
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent positions the image acquisition means (camera) at an angle to the optical axis, rather than directly in the light beam path. This angular arrangement allows the camera to capture reflected light from the measurement point without blocking the light emission, thereby maintaining full emitting surface area while enabling color measurement.

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

3Illumination intensity

If LED power is increased to compensate for light loss, then illumination intensity can be maintained, but thermal effects and LED lifespan are adversely affected

Engineering Contradiction:
Improvelight outputVSAvoidthermal effects
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The patent eliminates the need for high-power LEDs by removing the light guidance system. By placing low-power LEDs directly at the measurement point with a diffuser for uniform distribution, the system achieves sufficient illumination intensity without the thermal management issues associated with high-power LED operation.

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

4Ease of operation

If a bent distal end is provided for ergonomic application, then the device can be better applied against the tooth, but light guidance is affected by the bend or deformation

Engineering Contradiction:
Improveergonomic applicationVSAvoidlight guidance efficiency
Core Design Contradiction:
Ease of operationVSIllumination intensity

Solution Approach 1:

The patent replaces the light guidance system with direct LED placement at the bent distal end. This eliminates the problem of light guidance being affected by bends or deformations, while maintaining the ergonomic benefits of the bent shape for proper application against the tooth surface.

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

This configuration provides improved lighting homogeneity, reduced power consumption, and increased reproducibility, enhancing the precision and industrial quality of shade-taking processes while managing thermal stability and LED lifespan.

Implementation Method 1

hollow body being capable of transmitting the light from said light source from the proximal end to the distal end

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

protect the lens from photons emitted by said micro-LEDs by positioning reflective isolation means

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3420326B1Illumination device for an apparatus for establishing the color of a tooth, apparatus for establishing the color of a tooth, comprising said illumination device
Publication Date: 2023.04.19 BOREA
  • EP3420326B1 patent drawingFigure 1~2
  • EP3420326B1 patent drawingFigure 3~4
  • EP3420326B1 patent drawingFigure 5~6

AI summary

The invention relates to an illumination device for an apparatus for establishing the color of a tooth, including in the mouth, said illumination device comprising a support (10) with a lens system (12) that includes at least one lens, illumination means (14), image capturing means (16), and a front protection (18), characterized in that the illumination means (14) are arranged at the periphery of the visual field of the lens system (12).