Spectral Tuning and Daylight - Energy.govLED TRACK DISCUSSION III: LUMINAIRE CONCEPTS Spectral Tuning and Daylight Steve Paolini, Telelumen LLC. 30JAN19. Westin Hotel, Dallas, TX •

LED TRACK DISCUSSION III: LUMINAIRE CONCEPTS

Spectral Tuning and DaylightSteve Paolini, Telelumen LLC

30JAN19

Westin Hotel, Dallas, TX

• Founded 2007 – Saratoga, CA• Purpose – Replicate any spectral power distribution

• Products and services to create and playback light• Privately owned• Products:

• Octa (8 color light player luminaire) • Developer Software• LumenScripts/LightTunes (content)

Copyright Telelumen LLC 2019 All Rights Reserved

Target Applications• Healthcare – faster healing, wake/sleep improvement• Retail – make products more appealing• Workplace – increase productivity, wellbeing• Lighting company – designer spectrum, focus group evaluations• Horticulture – plant growth• Aquariums – fish, coral• Sensors – firmware development• Color quality – metrics, process control• Movie, TV – outdoor scene and filter replication


What is Mood/Human Centric Lighting?• Depends who you ask.• A fundamental aspect is the daylight experience. • Daylight is complex. The SPD changes with:

– time of day– the weather– time of year– place on earth– your immediate environment – window, sidewalk, park, …

• Chromaticity is typically not on the black body or daylight locus and does not define SPD.

• Fire can be relaxing, romantic, frightening


SPD is the definitive signature of light

CCT and chromaticity are not enough

Always provide/ask for the SPD


Tunable spectrum challenges

• Multi-channel drivers– Ideally both AM and PWM under digital control– At least 16-bits of dynamic range (future 20-bits)

• Multi channel color sensors– At least one sensor channel per color channel– Both product embedded and space deployed



• Color mixing – Less challenging for area sources

• Complete mixing may not be desirable in all cases

– More challenging for directed beam sources• No colored shadows



• Missing, inefficient wavelengths – Green gap, amber– No gaps from UV through IR– Efficiency a better metric than efficacy

• Efficient high luminance sources– Narrower beam than lambertian out of chip


Human centric challenges

• Human studies in the field with actual daylight– Track actual SPD exposure during the day over

various applications over various conditions


Efficacy vs. Efficiency

• Efficacy = lumens per electrical watt• Efficiency = optical watts per electrical watt

• Lumens are a weighted measure of optical watts with a peak at 555nm (green) and falling off toward red and blue.


Eye cone response for “standard observer”

Weighting for lumen

visiblespectrum


Octa – direct-green option

Telelumen LLC, copyright 2018, all rights reserved

Octa – violet option

Telelumen LLC, copyright 2018, all rights reserved

Efficacy vs. Efficiency



In general - SPD

• A more continuous spectrum and wider range of wavelengths produce higher color quality light sources.

• A less continuous spectrum and truncated range of wavelengths are often more efficacious.


Copyright Telelumen LLC 2019 All Rights ReservedData courtesy of Roland Connelly, AATCC

Copyright Telelumen LLC 2019 All Rights ReservedData courtesy of Dieter Lang, LEDVANCE, Germany

Reflectance Spectra of Skinhalf is between 600nm – 700nm

From: ”Face colour under varying illumination”, Chapter. 4; http://herkules.oulu.fi/isbn9514267885/html/i1030756.html

CaucasianAsian

African

© 2002 Oulu University Library

http://herkules.oulu.fi/isbn9514267885/html/i1030756.html

In the beginning

• Daylight• Fire

• Continuous spectrum• Intensity and spectrum change with time



Daylight Recording Locations






Como Italy Sky Light – May16


Day of sunlight• Illuminance sensor pointed up at a mostly blue sky in

Saratoga, California

• Starts: 28JUN18 at 05:48Ends: 28JUN18 at 20:48

• Lux range in actual recording: 10,000:1

• Color temperature range: 5,700K to 70,000K






Copyright Telelumen LLC 2018 All Rights ReservedCopyright Telelumen LLC 2018 All Rights Reserved


Summary

• Human centric lighting is rooted in our daylight experience.

• Daylight is complex – continuous spectrum and time are key.

• Multi-spectral luminaires are needed to replicate and maximize the value of the visible spectrum.


Thank [email protected]

mailto:[email protected]

Documents

Spectral Tuning and Daylight - Energy.govLED TRACK DISCUSSION III: LUMINAIRE CONCEPTS Spectral Tuning and Daylight Steve Paolini, Telelumen LLC. 30JAN19. Westin Hotel, Dallas, TX •