Tunable Circadian Light System with Consistent Color

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Solution Overview

Problem

Conventional light sources with tunable circadian effects often have varying color characteristics, leading to undesirable color perception and sub-optimal user experience due to widely different correlated color temperature (CCT) values and low color rendering index (CRI) values.

Innovation Solution

A light-emitting system comprising multiple light-emitting regions, each configured to emit light with specific melanopic ratios and CCT values, where the difference in melanopic ratios is significant (at least 0.1) while maintaining similar CCT values (within 1000 K) and CRI values (within 10), allowing for tunable circadian effects with consistent color characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional light sources adjust circadian effects by changing spectral content, then circadian effects are tuned, but color characteristics vary significantly

Engineering Contradiction:

Improvecircadian effectsVSAvoidcolor characteristics

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The light source is divided into multiple independent light-emitting regions, each with distinct spectral power distributions tailored to produce different circadian effects. This segmentation allows independent control of circadian impact for each region while maintaining consistent overall color characteristics when combined.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the light source are assigned different spectral qualities optimized for specific circadian functions. For example, certain regions emit light with higher melanopic ratios for alertness promotion, while others emit light with lower melanopic ratios for relaxation, yet all regions are designed to emit within a constrained CCT range to maintain color consistency.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If light sources emit different CCT values to achieve tunable circadian effects, then circadian effects are adjusted, but color perception becomes inconsistent

Engineering Contradiction:

Improvecircadian effectsVSAvoidcolor perception

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The invention changes the spectral power distribution parameters within constrained boundaries. Specifically, it adjusts the melanopic ratio and spectral content to achieve different circadian effects while maintaining the correlated color temperature parameter within a narrow range (e.g., 2000K to 10000K), thereby preserving consistent color perception across different circadian modes.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If conventional light sources prioritize circadian tuning, then circadian effects are optimized, but color rendering quality decreases

Engineering Contradiction:

Improvecircadian effectsVSAvoidcolor rendering index

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The light source employs a composite spectral approach by combining emissions from multiple light-emitting regions with different spectral power distributions. This composite approach allows the overall light output to achieve high melanopic ratios for circadian optimization while simultaneously maintaining high color rendering index values through the complementary spectral contributions of different regions.

Inventive Principle:

Principle #40Composite materials

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 system provides improved user experience by maintaining consistent color characteristics and high-quality light emission, reducing disruption and promoting health benefits by mimicking natural circadian rhythms, suitable for applications like night shift work.

Implementation Method 1

The light source comprises a first light-emitting diode and a second light-emitting diode

Methodology Applied

Scientific EffectLight Emitting Diode: Light Emitting Diode

Implementation Method 2

a first wavelength-converting material configured to convert light emitted by the first light-emitting diode to light having a first spectral power distribution

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentUS20200405997A1Systems for emitting light with tunable circadian effects and substantially consistent color characteristics and methods of making and/or operating the same

Publication Date: 2020.12.31 SHAN QIFENG

AI summary

Aspects of the present disclosure relate to systems for emitting light (e.g., substantially white light) with tunable circadian effects and substantially consistent color characteristics, and methods of making and/or operating the same. Certain embodiments described herein are systems comprising a plurality of light-emitting regions configured to emit light having certain circadian effects (e.g., melanopic ratio) and certain color characteristics (e.g., corrected color temperature (CCT), color rendering index (CRI)). According to some embodiments, the difference between the circadian effects of the light-emitting regions may be relatively large, and the difference between the color characteristics of the light-emitting regions may be relatively small. Each light-emitting region may comprise one or more light-emitting diodes (LEDs), each of which may be associated with one or more wavelength-converting materials (e.g., phosphors).