Color Temperature Lighting Control for Melanopic Ratio Tuning

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Solution Overview

Problem

Conventional lighting systems do not adequately consider the influence on human circadian rhythms and melanopic effects, which are crucial for creating a healthy indoor environment as per the WELL Standard.

Innovation Solution

A lighting device comprising at least three light emitting devices with different chromaticity coordinates, allowing for control of color temperature within a specific range to optimize melanopic ratio and circadian response, using nitride semiconductors and fluorescent materials to emit light along the black body radiation locus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional lighting systems are used, then good luminous efficiency and high color rendering properties are achieved, but the influence on human circadian rhythms is not adequately considered

Engineering Contradiction:
Improveinfluence on human circadian rhythmsVSAvoidcolor temperature control range
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The lighting system is divided into multiple independent light emitting devices with different chromaticity coordinates (first, second, and third light emitting devices). Each device can be controlled independently to adjust the overall color temperature and melanopic ratio, enabling separate optimization of circadian impact and color rendering properties

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent combines multiple light emitting devices with different spectral characteristics to create a composite lighting system. This composite approach allows the system to achieve both high color rendering (Ra≥80) and significant melanopic ratio variation (≥0.35) across the color temperature range, simultaneously addressing color rendering requirements and circadian rhythm considerations

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If lighting systems focus on color rendering properties, then high color rendering index is achieved, but melanopic ratio control for circadian rhythm is insufficient

Engineering Contradiction:
Improvemelanopic ratio controlVSAvoidnumber of light emitting devices
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Each light emitting device is designed with specific chromaticity coordinates that serve multiple functions: the first device (x1≤0.15, y1≤0.25) contributes to both color temperature adjustment and melanopic ratio control, the second device (x2≥0.45, y2≤0.55) provides color rendering and color temperature stabilization, while the third device (x3≤0.60, y3≥0.40) enhances color rendering and adjusts the overall spectral distribution. This multi-functional design enables the system to achieve both circadian rhythm control and high color rendering with a manageable number of components

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

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 lighting device effectively changes the melanopic ratio over a wide color temperature range, enhancing the circadian rhythm influence and providing a healthier lighting environment while maintaining comparable luminous efficiency and color rendering properties.

Implementation Method 1

first light emitting device (101), second light emitting device (102), and third light emitting device (103), respectively, emit lights with different chromaticity coordinates

Methodology Applied
Scientific EffectLight Emitting Diode: Light Emitting Diode

Implementation Method 2

using nitride semiconductors and fluorescent materials to emit light along the black body radiation locus

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP4054294B1Lighting device and color temperature control system
Publication Date: 2025.03.19 NICHIA CORP
  • EP4054294B1 patent drawingFigure 1
  • EP4054294B1 patent drawingFigure 2
  • EP4054294B1 patent drawingFigure 3

AI summary

Provided is an illumination in consideration of influence on a human body. A lighting device including a first light emitting device that emits light of first chromaticity coordinates and has a high melanopic ratio, a second light emitting device that emits light of second chromaticity coordinates, and a third light emitting device that emits light of third chromaticity coordinates and has a low melanopic ratio, wherein light in a range from a first temperature to a second temperature on the black body radiation locus is included in a triangular area surrounded by a straight line connecting the first chromaticity coordinates and the second chromaticity coordinates, a straight line connecting the second chromaticity coordinates and the third chromaticity coordinates, and a straight line connecting the third chromaticity coordinates and the first chromaticity coordinates, in the chromaticity diagram of the CIE1931 color system.