Sleepy light

1. A lighting device comprising

a 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

MEF

=

1.22

·

∑

λ

=

380

⁢

⁢

nm

λ

=

780

⁢

⁢

nm

⁢

(

SPD

⁡

(

λ

)

·

m

⁡

(

λ

)

)

∑

λ

=

380

⁢

⁢

nm

λ

=

780

⁢

⁢

nm

⁢

(

SPD

⁡

(

λ

)

·

V

⁡

(

λ

)

)

wherein SPD(λ) defines the spectral power distribution of the light source light emitted by the respective light source,

wherein m(λ) is the normalized melanopic sensitivity function and

wherein V(λ) 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.

2. The lighting device according to claim 1 , wherein the difference between the CRI of the first light source light and the CRI of the second light source light is at least 20 CRI units.

3. The lighting device according to claim 1 , wherein the CRI of the second light source light is equal to or smaller than 60 CRI units.

4. The lighting device according to claim 1 , wherein said second light source is configured to provide said second light source light, having a 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 of 380-780 nm of at maximum 0.01.

5. The lighting device according to claim 1 , wherein said first light source light has a MEF value MEF 1 and wherein said second light source light has a MEF value MEF 2 , wherein MEF 2 <MEF 1 .

6. The lighting device according to claim 5 , wherein said first light source and said second light source are configured to provide said first light source light and said second light source light, respectively, having a difference in MEF of at least 0.05.

7. The lighting device according to claim 6 , wherein said first light source is configured to provide said first light source light having said MEF 1 value selected from the range of 0.2-0.4, and wherein said second light source is configured to provide said second light source light having said MEF 2 value selected of at maximum 0.15.

8. The lighting device according to claim 1 , wherein the first light source comprises one or more solid state light sources, and wherein the second light source comprises one or more solid state light sources, wherein the second light source comprises at least a solid state light source configured to provide amber light.

9. The lighting device according to claim 1 , comprising a light exit window configured to transmit at least part of said first light source light and said second light source light.

10. The lighting device according to claim 1 , wherein the lighting device is configured to provide lighting device light comprising one or more of said first light source light and said second light source light, wherein the control system is configured to control one or more of an intensity of the lighting device light and a spectral composition of said lighting device light as function of one or more of (i) an ambient light sensor signal, (ii) a motion sensor signal, (iii) a sound sensor signal, (iv) a timer signal, (v) a date signal, and (vi) a user interface signal.

11. The lighting device according to claim 1 , further comprising a user interface wherein the user interface comprises one or more of a remote user interface and a user interface integrated in a lighting unit comprising said first light source and said second light source.

12. A lighting system comprising:

the lighting device according to claim 1 , wherein the lighting device is configured to provide lighting device light comprising one or more of said first light source light and said second light source light, and

a user interface functionally coupled to the control system, wherein the control system is configured to control one or more of an intensity of the lighting device light and a spectral composition of said lighting device light as function of a user interface signal.

13. The lighting system of claim 12 , further comprising a timer functionally coupled to the control system, wherein the control system is configured to control one or more of an intensity of the lighting device light and a spectral composition of said lighting device light as function of a timer signal or a date signal.

14. The lighting system of claim 12 , further comprising a sensor functionally coupled to the control system, wherein the control system is configured to control one or more of an intensity of the lighting device light and a spectral composition of said lighting device light as function of one or more of (i) an ambient light sensor signal, (ii) a motion sensor signal and (iii) a sound sensor signal.

15. The lighting device according to claim 1 , wherein the first light source light has a correlated color temperature CCT of at maximum 3000 K and a color rendering index CRI of at least 75, and wherein the second light source light has a dominant wavelength selected from the range of 575-780 nm and a color rendering index of at maximum 70.