US Patent No. 10,257,902

SLEEPY LIGHT


Patent No. 10,257,902
Issue Date April 09, 2019
Title Sleepy Light
Inventorship Marius Leendert Trouwborst, Den Bosch (NL)
Berent Willem Meerbeek, Veldhoven (NL)
Assignee SIGNIFY HOLDING B.V., Eindhoven (NL)

Claim of US Patent No. 10,257,902

1. A lighting device comprisinga first light source configured to provide first light source light,
a second light source configured to provide second light source light and
a control system configured to control the first light source and the second light source to provide said first light source light and second light source light respectively, wherein
the first light source light and the second light source light each have a melanopsin effectiveness factor (MEF) of a maximum 0.40 and wherein MEF is defined as

wherein SPD(?) defines the spectral power distribution of the light source light emitted by the respective light source,
wherein m(?) is the normalized melanopic sensitivity function and
wherein V(?) is the normalized photopic sensitivity function, and wherein
the first light source light and the second light source light have a color rendering index (CRI), the difference between the CRI of the first light source light and the CRI of the second light source light is at least 15 CRI units, and wherein
at least the first light source is arranged to provide the first light source light having a maximum ratio of the total number of photons in the wavelength range of 440-530 nm to the total number of photons in the wavelength range 380-780 nm of 0.2.