Lighting device with switching material
A lighting device comprises a light-emitting module with light-emitting elements, wherein the light-emitting elements are arranged adjacent to each other and are configured to emit light towards a light-emitting side. The light-emitting module is configured such that the light-emitting elements can be addressed partially independently of each other, such that some may be brought into a switched-on state while others are brought into a switched-off state. A top layer is disposed on the light-emitting module at the light-emitting side. Further comprising a switching material capable of a reversible change in transmittance for the light emitted by changing to a higher transmittance in regions where the top layer situated on light-emitting elements in the switched-on state or to a lower transmittance in regions of the top layer situated in the switched-off state. The invention further refers to methods for producing and operating a lighting device and using a lighting device.
1. A device comprising:
an adjustable-transmittance layer having independently-addressable regions each formed from a thermochromic material that is configured to change states, in response to a temperature change of the region, between a lower transmittance state and a higher transmittance state that has a higher transmittance than the lower transmittance state to light of a predetermined wavelength; and
light-emitting diodes configured to emit light from a light-emitting face opposing the adjustable-transmittance layer, adjacent light-emitting diodes disposed such that cross-talk is present between the adjacent light-emitting diodes due to lateral light diffusion from one of the adjacent light-emitting diodes in a switched-on state to another of the adjacent light-emitting diodes in a switched-off state.
2. The device according to claim 1 , wherein a distance between the adjacent light-emitting diodes is in a same order of magnitude as a dimension of the light-emitting face of each of the adjacent light-emitting diodes.
3. The device according to claim 1 , wherein a distance between the adjacent light-emitting diodes is smaller than a dimension of the light-emitting face of each of the adjacent light-emitting diodes.
4. The device according to claim 1 , wherein side faces of the adjacent light-emitting diodes abut each other.
5. The device according to claim 1 , wherein the light-emitting diodes are configured to emit light of the predetermined wavelength from the light-emitting face.
6. The device according to claim 1 , further comprising wavelength conversion elements disposed between the light-emitting diodes and the adjustable-transmittance layer, the wavelength conversion elements configured to emit light of the predetermined wavelength.
7. The device according to claim 1 , further comprising at least one of a heating device and a cooling device configured to independently adjust a temperature of each of the regions.
8. The device according to claim 1 , wherein:
waste heat of the light-emitting diodes is used to independently adjust a temperature of each of the regions, and
the waste heat is provided to the adjustable-transmittance layer via convection.
9. The device according to claim 1 , wherein:
waste heat of the light-emitting diodes is used to independently adjust a temperature of each of the regions, and
the waste heat is provided to the adjustable-transmittance layer by heat conducting elements.
10. The device according to claim 1 , wherein the thermochromic material in each of the regions is encapsulated, the adjustable-transmittance layer comprising an inner section containing the thermochromic material and an outer section comprising a protective material surrounding the thermochromic material.
11. The device according to claim 1 , wherein the thermochromic material in each of the regions is provided as a coating on a layer disposed between the thermochromic material and the light-emitting diodes.
12. The device according to claim 1 , wherein the light-emitting diodes are independently-addressable.
13. The device according to claim 1 , wherein the device is an automotive headlight.
14. The device according to claim 1 , wherein the device is a camera flash.
15. A method of providing light from a device, the method comprising:
driving light-emitting diodes to emit light from a light-emitting face;
disposing adjacent light-emitting diodes such that cross-talk is present between the adjacent light-emitting diodes due to lateral light diffusion from one of the adjacent light-emitting diodes in a switched-on state to another of the adjacent light-emitting diodes in a switched-off state; and
limiting light emission of the device from the light-emitting diodes using an adjustable-transmittance layer, the adjustable-transmittance layer having independently-addressable regions each formed from a thermochromic material that is configured to change states, in response to a temperature change of the region, between a lower transmittance state and a higher transmittance state that has a higher transmittance than the lower transmittance state to light of a predetermined wavelength.
16. The method according to claim 15 , further comprising independently adjusting a temperature of each of the regions using at least one of a heating device and a cooling device.
17. The method according to claim 15 , wherein:
the light emission is limited using waste heat of the light-emitting diodes to independently adjust a temperature of each of the regions, and
the method further comprising providing the waste heat to the adjustable-transmittance layer via at least one of convection and heat conducting elements.
18. The method according to claim 15 , wherein in each of the regions switching is provided as a coating on a layer disposed between the thermochromic material and the light-emitting diodes, the coating applied to at least one side of the layer as a deposited material, the deposited material selected from a group of deposited materials that include a slurry, powder, solvent-based ink, and resin.
19. A display comprising:
an adjustable-transmittance layer having independently-addressable regions each formed from a thermochromic material that is configured to change states, in response to a temperature change of the region, between a lower transmittance state and a higher transmittance state that has a higher transmittance than the lower transmittance state to light of a predetermined wavelength; and
light-emitting diodes configured to emit light from a light-emitting face opposing the adjustable-transmittance layer, adjacent light-emitting diodes disposed such that cross-talk is present between the adjacent light-emitting diodes due to lateral light diffusion from one of the adjacent light-emitting diodes in a switched-on state to another of the adjacent light-emitting diodes in a switched-off state, waste heat of the light-emitting diodes used to independently adjust a temperature of each of the regions.
20. The display according to claim 19 , wherein the adjustable-transmittance layer comprises another layer having regions of an electrochromic material whose transmittance changes with applied voltage, each region of the electrochromic material overlapping a unique region formed from the thermochromic material.