Lighting module, a lighting system and a method of lighting

1. A lighting module comprising:

a plurality of first light sources configured for emitting first light in a first predetermined direction,

at least one second light source configured for emitting second light,

a light guide comprising a first light in-coupling portion for coupling at least a part of the first light into the light guide, a second light in-coupling portion for coupling at least a part of the second light into the light guide, and a plurality of light out-coupling portions for coupling of at least part of the second light out of the light guide,

wherein the light guide is arranged for guiding the second light coupled into the light guide at the at least one light in-coupling portion via total internal reflection to the plurality of light out-coupling portions for generating out-coupled light in a second predetermined direction,

wherein the light guide is mechanically coupled to and extends along the plurality of first light sources,

wherein the light out-coupling portions extend along the plurality of first light sources and cover a larger first area than an second area covered by the plurality of first light sources, and

wherein a total luminous flux generated by the at least one second light source is lower than a total luminous flux generated by the plurality of the first light sources,

wherein the first predetermined direction and the second predetermined direction at least partly overlap, and

wherein the ratio Ei:E1 is 80% or less, wherein Ei1 is the amount of photons emitted by the plurality of first light sources and impinging on the first light in-coupling portion, and E1 is the amount of photons emitted by the plurality of first light sources.

2. A lighting module according to claim 1 , wherein the first term I2/E2 is larger than the second term I1/E1, wherein I1 is the amount of in-coupled photons emitted by the plurality of first light sources and that is coupled into a portion of the light guide, I2 is the amount of in-coupled photons emitted by the at least one second light source and that is coupled into the light guide, E1 is the amount of photons emitted by the plurality of first light sources, and E2 is the amount of photons emitted by the at least one second light source.

3. A lighting module according to claim 1 , wherein the ratio of the first term I2/E2 with respect to the second term I1/E1 is at least 3.

4. A lighting module according to claim 1 , wherein the plurality of first light sources is arranged for emitting the first light in a beam, wherein the light guide is arranged in the path of the beam, and wherein the second term I1/E1 is 0.1 or less.

5. A lighting module according to claim 1 , wherein the second distance (D 2 ) between the light guide and the plurality of first light sources is in the range from 1 to 20 mm.

6. A lighting module according to claim 1 , wherein the light guide is elongated and has a length (L), a width (W) and height (H) wherein the length (L) is at least 30 times the width (W) and the length (L) is at least 50 times the height (H).

7. A lighting module according to claim 1 , wherein the light guide is arranged on top of the light output area of more than 90% of the plurality of first light sources, wherein the light out-coupling portions of the light guide are interleaved with respect to the first light sources.

8. A lighting module according to claim 1 , wherein the light guide comprises a center part and a peripheral part, the refractive index of the center part is at least 1.02 times higher than the refractive index of the peripheral part.

9. A lighting module according to claim 1 , wherein the plurality of first light sources are spaced at a pitch (P) of at least 5 mm.

10. A lighting module according to claim 1 , comprising at least a transparent carrier arranged between the plurality of first light sources and the light guide wherein the light guide is attached to or embedded in the at least partly transparent carrier.

11. A lighting system comprising said lighting module according to claim 1 , further comprising a control unit electrically connected to the plurality of first light sources and the at least one second light source for separately controlling the amount of first light and second light.

12. A lighting system comprising said lighting module according to claim 11 , further comprising at least one sensor configured for sensing the ambient light intensity, color and/or color temperature in a region surrounding the lighting system, and wherein the control unit is communicatively coupled to at least the at least one sensor, the plurality of first light sources and the at least one second light source, the control unit being configured for controlling operation of the plurality of first light sources and the at least one second light source based on information regarding the light intensity, color and color temperature in the region obtained by the at least one sensor for controlling the intensity of the lighting system in dependence on the ambient lighting.

13. A lighting system comprising said lighting module according to claim 11 , further comprising a clock module for supplying the time of a day and the control unit communicatively coupled to the clock module, the plurality of first light sources and the at least one second light source, the control unit being configured for controlling operation of the plurality of first light sources and the at least one second light source based on information regarding the time of the day.

14. A method of lighting using lighting system according to claim 11 comprising switching by the control unit the lighting module between a first state in which the plurality of first light sources emit the first light and the at least one second light source does or does not emit the second light, and a second state in which the plurality of the first light sources do not emit the first light and the at least one second light source emits the second light.