What is it
Enhancing Biological Clock by Circadian Lighting

Circadian lighting is the technology of programming the intensity and color temperature of the light delivered by a luminaire to suit the Circadian Rhythm of human body.  It is also know as human-centric lighting. The employed light source should be able to deliver high dosage of blue-turquoise light within the blue light content to regulate the circadian entrainment.

The average daylight in North America is roughly represented by CIE Standard Illuminant D65. During daytime, sunlight plays the most significant part in regulating the Circadian Rhythm of human body.

Nowadays, people are spending more and more time indoors during the day, and thus the time of the eyes being exposed to blue-enriched sunlight is reduced. Eye exposure to appropriate amounts of sunlight during the daytime is healthful, and it helps cognitive function, elevates moods and synchronizes body-clock.

Medical studies show that the light intensity and blue wavelength suppress Melatonin secretion.  Melatonin is a hormone, which creates the Circadian Rhythm (sleep-wake cycle) and helps people sleep. Higher level of Melatonin makes people sleepy, while lower level makes people alert.  Thus it is more beneficial for the body to have brighter light with cool white color (containing more blue wavelength) in the daytime, while dimmer light with warm white color (containing lesser blue wavelength) may be used in the evening.
Setting scenes in accordance with Circadian Rhythm

The Timer function of DaliTablet is especially suitable to schedule the light intensities and color temperatures in accordance with the user's desired Circadian Rhythm.  Three scenes are set within a 24-hour interval by DaliTablet shown in the photo at the left, and its settings are shown in the below table.  Brighter light with cool white color (containing higher blue light content) is scheduled after waking up in the morning.   Neutral white color (containing lesser blue light content) is scheduled in the afternoon, and dimmer light with warm white color (containing minimum blue light content) is scheduled in the evening.
Scene Time Illuminance CCT
Scene 11 7:00 am 400 lux Bright light 5000K Cool white
Scene 12 2:00 pm 300 lux Bright light 4000K Neutral white
Scene 13 6:00 pm 100 lux Dim light 3000K Warm white
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