Lighting Device that Deactivates Dangerous Pathogens While Providing Visually Appealing Light

1 . A lighting device configured to deactivate pathogens in an environment, the lighting device comprising:

at least one first light-emitting element configured to emit light having a wavelength of between 400 nm and 420 nm, wherein the light emitted by the at least one first light-emitting element is configured to deactivate the pathogens in the environment; and

at least one second light-emitting element configured to emit light having a wavelength of greater than 420 nm,

wherein a first combined light output of the light emitted by the at least one first light-emitting element and the light emitted by the at least one second light-emitting element comprises visible light that is perceived as white light, the white light having u′, v′ coordinates on the 1976 CIE Chromaticity Diagram that lie on a curve that is between 0.035 Duv below and 0.035 Duv above a planckian locus defined by the ANSI C78.377-2015 color standard, and the white light having a color rendering index of at least 60 and a first color temperature of between approximately 1500K and 7000K.

2 . The lighting device of claim 1 , wherein the at least one first light-emitting element is configured to emit at least 4 watts of light.

3 . The lighting device of claim 1 , wherein the light emitted by at least one first light-emitting element has a minimum integrated irradiance of 0.05 mw/cm 2 measured from any unshielded point in the environment that is 1.5 m from any point on any external-most luminous surface of the lighting device.

4 . The lighting device of claim 1 , wherein the light emitted by the at least one second light-emitting element has a greater luminous flux than the light emitted by the at least one first light-emitting element.

5 . The lighting device of claim 1 , wherein a radiometric power at 20 degrees from a center axis of light distribution that is equal to 50% of a radiometric power at the center axis of light distribution, wherein the radiometric power at 20 degrees and the radiometric power at the center axis are measured at equal distances from the at least one first light-emitting element or the at least one second light-emitting element.

6 . The lighting device of claim 5 , wherein a radiometric power at 30 degrees from a center axis of light distribution is equal to 50% of a radiometric power at the center axis of light distribution, wherein the radiometric power at 30 degrees and the radiometric power at the center axis are measured at equal distances from the at least one first light-emitting element or the at least one second light-emitting element.

7 . The lighting device of claim 1 , wherein the combined light output has a luminous flux above a cone angled downward from the lighting device at 60 degrees circumferentially around nadir of the lighting device, and wherein the luminous flux is greater than 15%, 20%, 25%, or 30% of a total luminous flux of the combined light output.

8 . The lighting device of claim 1 , wherein the at least one second light-emitting element is configured to emit light having a wavelength of greater than 500 nm.

9 . The lighting device of claim 1 , wherein the white light has a color rendering index of above 80.

10 . The lighting device of claim 1 , wherein the white light has a color temperature of between approximately 1800 degrees and approximately 5000 degrees Kelvin.

11 . The lighting device of claim 1 , wherein the curve is between 0.02 Duv below and 0.02 Duv above a planckian locus.

12 . The lighting device of claim 1 , further comprising:

a controller configured to control the light emitted by the at least one first light-emitting element and the at least one second light-emitting element; and

at least one power source electrically connected to the controller and configured to power the at least one first light-emitting element and the at least one second light-emitting element,

wherein the controller is configured to:

receive a dimmer light setting comprising a ratio of a second combined light output of the light emitted by the at least one first light-emitting element and the light emitted by the at least one second light-emitting element to the first combined light output, the second combined light output being less than the first combined light output; and

responsive to receiving the dimmer light setting, cause the at least one power source to power the at least one first light-emitting element and the at least one second light-emitting element according to the dimmer light setting, the second combined light output having a second color temperature less than the first color temperature.

13 . The lighting device of claim 12 , wherein the at least one power source comprises:

at least one first driver configured to power the at least one first light-emitting element; and

at least one second driver configured to power the at least one second light-emitting element.

14 . The lighting device of claim 12 , wherein the first combined light output comprises a first ratio of a first level of light emitted by the at least one first light-emitting element to a second level of light emitted by the at least one second light-emitting element, and wherein the second combined light output comprises a second ratio of a third level of light emitted by the at least one first light-emitting element to a fourth level of light emitted by the at least one second light-emitting element, the second ratio being different than the first ratio.

15 . A lighting device configured to deactivate pathogens in an environment, the lighting device comprising:

at least one first light-emitting element configured to emit light having a wavelength of between 400 nm and 420 nm, wherein the light emitted by the at least one first light-emitting element is configured to deactivate the pathogens in the environment; and

at least one second light-emitting element configured to emit light having a wavelength of greater than 420 nm,

wherein a first combined light output of the light emitted by the at least one first light-emitting element and the light emitted by the at least one second light-emitting element comprises visible light that is perceived as white light, the white light having u′, v′ coordinates on the 1976 CIE Chromaticity Diagram that lie on a curve that is between 0.035 Duv below and 0.035 Duv above a planckian locus defined by the ANSI C78.377-2015 color standard, and the white light having a color rendering index of at least 60 and a first color temperature of between approximately 1500K and 7000K, and

wherein the light emitted by at least one first light-emitting element has a minimum integrated irradiance of 0.05 mw/cm 2 measured from any unshielded point in the environment that is 1.5 m from any point on any external-most luminous surface of the lighting device.

16 . The lighting device of claim 15 , wherein the minimum integrated irradiance comprises 0.10, 0.15, 0.20, 0.25, or 0.30 mw/cm2.

17 . The lighting device of claim 15 , wherein the at least one first light-emitting element is configured to emit at least 4 watts of light.

18 . The lighting device of claim 15 , wherein the light emitted by the at least one second light-emitting element has a greater luminous flux than the light emitted by the at least one first light-emitting element.

19 . The lighting device of claim 15 , wherein a radiometric power at 20 degrees from a center axis of light distribution that is equal to 50% of a radiometric power at the center axis of light distribution, wherein the radiometric power at 20 degrees and the radiometric power at the center axis are measured at equal distances.

20 . The lighting device of claim 15 , wherein the combined light output has a luminous flux above a cone angled downward from the lighting device at 60 degrees circumferentially around nadir of the lighting device, and wherein the luminous flux is greater than 15%, 20%, 25%, or 30% of a total luminous flux of the combined light output.

21 . The lighting device of claim 15 , wherein the white light has a color rendering index of above 80 and a color temperature of between approximately 1800 degrees and approximately 5000 degrees Kelvin.

22 . The lighting device of claim 15 , wherein the lighting device comprises a sealingly enclosed housing, and wherein each of the at least one first light-emitting element and the second light-emitting element is arranged on or within the enclosed housing.

23 . The lighting device of claim 15 , further comprising:

a controller configured to control the light emitted by the at least one first light-emitting element and the at least one second light-emitting element; and

at least one power source electrically connected to the controller and configured to power the at least one first light-emitting element and the at least one second light-emitting element,

wherein the controller is configured to:

receive a dimmer light setting comprising a ratio of a second combined light output of the light emitted by the at least one first light-emitting element and the at least one second light-emitting element to the first combined light output, the second combined light output being less than the first combined light output; and

responsive to receiving the first light setting, cause the at least one power source to power the at least one first light-emitting element and the at least one second light-emitting element according to the dimmer light setting, the second combined light output having a second color temperature less than the first color temperature.

24 . The lighting device of claim 23 , wherein the first combined light output comprises a first ratio of a first level of light emitted by the at least one first light-emitting element to a second level of light emitted by the at least one second light-emitting element, and wherein the second combined light output comprises a second ratio of a third level of light emitted by the at least one first light-emitting element to a fourth level of light emitted by the at least one second light-emitting element, the second ratio being different than the first ratio.

25 . A method of providing visually appealing light while deactivating pathogens in an environment, the method comprising:

emitting a first level of visible light from a plurality of light-emitting elements of a lighting device installed in the environment, the first level of visible light having u′, v′ coordinates on the 1976 CIE Chromaticity Diagram that lie on a curve that is between 0.035 Duv below and 0.035 Duv above a planckian locus defined by the ANSI C78.377-2015 color standard, and the first level of visible light having a color rendering index of at least 60 and a first color temperature of between approximately 1500K and 7000K, wherein a component of the first level of visible light comprises light having a wavelength of between 400 nm and 420 nm and configured to deactivate the pathogens in the environment, and wherein the component of the first level of visible light has a minimum integrated irradiance of 0.05 mw/cm 2 measured from any unshielded point in the environment that is 1.5 m from any point on any external-most luminous surface of the lighting device.

26 . The method of claim 25 , further comprising:

receiving a dimmer light setting comprising a ratio of a second level of visible light emitted by the plurality of light-emitting elements to the first level of visible light, the second level of visible light being less than the first level of visible light; and

causing at least one power source to power the plurality of light-emitting elements according to the dimmer light setting, the second level of visible light having a second color temperature less than the first color temperature.