Programmable LED Light Engine for Uniform Color and Melanopic Flux

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Solution Overview

Problem

LED lighting systems face challenges in achieving uniform color points and sufficient melanopic flux, particularly in the 480-500 nm region, due to material and process variations, leading to inconsistent color output and potential retinal oxidative stress from blue light exposure.

Innovation Solution

A programmable LED light engine with integrated color tuning capability, using a combination of white LEDs and monochromatic LEDs like cyan and hyper-red, adjusts electrical current to match target color points and spectral characteristics, ensuring consistent color output and rich melanopic flux through a nano-tuner circuit and microcontroller-driven switching circuitry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional LED mixing methods are used to produce white light, then a wide variety of color outputs can be achieved, but uniform color points and sufficient melanopic flux cannot be guaranteed due to material and process variations

Engineering Contradiction:

Improvecolor output varietyVSAvoidcolor point uniformity

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent segments the LED system into multiple independently controllable channels, each dedicated to specific wavelength ranges (e.g., 480-500nm for melanopic, 620-680nm for deep red). This segmentation allows precise control over spectral content by adjusting individual channel intensities, ensuring uniform color points and sufficient melanopic flux despite material variations in mass-produced LEDs

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by enhancing specific wavelength regions with targeted LED channels. Instead of relying on broad-spectrum white LEDs with inconsistent spectral power distribution, the system selectively boosts melanopic-rich (480-500nm) and deep red (620-680nm) regions using dedicated monochromatic or narrow-band LEDs, ensuring consistent spectral characteristics across production batches

Inventive Principle:

Principle #3Local quality

2Use of energy by moving object

If blue pump LED with phosphor is used to generate white light, then lighting efficiency can be improved, but melanopic flux in the 480-500 nm region becomes insufficient

Engineering Contradiction:

Improvelighting efficiencyVSAvoidmelanopic flux

Core Design Contradiction:

Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The patent merges a phosphor-converted white LED channel (for general illumination efficiency) with dedicated monochromatic/narrow-band LED channels in the 480-500nm melanopic-rich range. This combination maintains the energy efficiency of phosphor downconversion while supplementing the deficient melanopic flux through additional targeted LED sources, achieving both high lighting efficiency and sufficient melanopic stimulation

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If LED output is increased to provide sufficient melanopic flux, then circadian rhythm entrainment improves, but retinal oxidative stress from blue light exposure increases

Engineering Contradiction:

Improvecircadian rhythm supportVSAvoidretinal oxidative stress

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the spectral parameters by shifting emphasis from peak blue (440-465nm) to cyan/blue-green (480-500nm) wavelengths for melanopic stimulation. This parameter change allows effective circadian rhythm entrainment through melanopic-rich light while reducing the harmful blue light component that causes retinal oxidative stress, as the 480-500nm region is less associated with blue light hazard

Inventive Principle:

Principle #35Parameter changes

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 solution provides uniform and visually appealing illumination with enhanced melanopic flux, reducing retinal oxidative stress and ensuring consistent color temperature, while dynamically adjusting to maintain optimal non-visual stimulus and circadian rhythm entrainment.

Implementation Method 1

Light emitting diode (LED) technology is a maturing technology that continues to show improvements in efficiency, customability and cost reduction

Methodology Applied

Scientific EffectLight emitting diode (LED): Light Emitting Diode

Implementation Method 2

Another method for generating white or near-white light is by using a lumiphor such as a phosphor in conjunction with a blue 'pump' LED

Methodology Applied

Scientific EffectPhosphor conversion: Photoluminescence

Data Source

PatentUS9788387B2Systems and methods for controlling the spectral content of LED lighting devices

Publication Date: 2017.10.10 BIOLOGICAL INNOVATION & OPTIMIZATION SYSTEMS LLC

AI summary

Systems and methods for improving color accuracy and uniformity in LED illumination systems are disclosed including light engines and switching circuits for controlling the addition or subtraction of light from one or more color light sources of the light engines to produce light of a uniform and consistent color. Systems and methods of providing LED light engines and associated illumination spectrums that are both visually appealing and rich in melanopic flux are also disclosed.