Lamp

Abstract

A lamp is disclosed. In an embodiment, the lamp includes a first light source and a second light source embodied as a light-emitting reflector, with a reflective layer and an electroluminescent layer sequence. The second light source is deformable such that an emission pattern of light emitted by the first light source and reflected by the light-emitting reflector is modifiable.

Claims

1-10. (canceled)

11. A lamp comprising: a first light source; and a second light source embodied as a light-emitting reflector with a reflective layer and an electroluminescent layer sequence, wherein the second light source is deformable such that an emission pattern of light emitted by the first light source and reflected by the light-emitting reflector is modifiable.

12. The lamp according to claim 11, wherein the electroluminescent layer sequence comprises an organic functional layer stack with at least one organic light-emitting layer.

13. The lamp according to claim 12, wherein the organic functional layer stack is arranged between two electrodes.

14. The lamp according to claim 13, wherein the reflective layer comprises one of the electrodes.

15. The lamp according to claim 12, wherein the organic functional layer stack is formed in a large-area fashion over the reflective layer.

16. The lamp according to claim 11, wherein the electroluminescent layer sequence comprises an organic light-emitting diode.

17. The lamp according to claim 11, wherein the first light source is spaced apart from the second light source.

18. The lamp according to claim 11, wherein the first light source is a point light-type light source.

19. The lamp according to claim 18, wherein the first light source comprises an inorganic light-emitting diode.

20. The lamp according to claim 18, wherein the first light source comprises an incandescent lamp.

21. The lamp according to claim 18, wherein the first light source comprises a gas discharge lamp.

22. The lamp according to claim 11, wherein the lamp is part of a motor vehicle headlight.

23. The lamp according to claim 11, wherein the lamp is part of a flashlight.

24. The lamp according to claim 11, wherein the lamp is part of a head torch or headlamp.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Further advantages, advantageous embodiments and further developments are revealed by the exemplary embodiments described below in connection with the figures, in which:

[0023] FIG. 1 shows a schematic representation of a lamp with a first and a second light source according to one exemplary embodiment,

[0024] FIGS. 2 and 3 show schematic representations of second light sources for lamps according to further exemplary embodiments,

[0025] FIG. 4 shows a schematic representation of a lamp according to a further exemplary embodiment,

[0026] FIGS. 5A and 5B show schematic representations of a lamp according to a further exemplary embodiment, and

[0027] FIGS. 6A to 6B show schematic representations of a lamp according to a further exemplary embodiment.

[0028] In the exemplary embodiments and figures, identical, similar or identically acting elements are provided in each case with the same reference numerals. The elements illustrated and their size ratios to one another should not be regarded as being to scale, but rather individual elements, such as, for example, layers, components, devices and regions, can have been made exaggeratedly large to illustrate them better and/or to aid comprehension.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0029] FIG. 1 shows an exemplary embodiment of a lamp 100 which comprises a first light source 101 and a second light source 102 spaced therefrom. The lamp 100 can, for example, be at least part of a motor vehicle headlamp, a torch or a head torch. Depending on the function and application of the lamp 100, the first and second light sources 101, 102 can emit the same or different light.

[0030] The first light source 101 is a point light-type light source, which comprises or consists of an inorganic light-emitting diode, an incandescent lamp, a gas discharge lamp or a plurality or combination of these. For example, the first light source 101 can comprise one or more light-emitting diodes in the form of light-emitting diode chips which are arranged on a carrier or in a package. Furthermore, the first light source 101 can, for example, also comprise or consist of a conventional incandescent bulb, a tungsten-halogen lamp, a metal-halide lamp and/or a xenon gas discharge lamp.

[0031] The second light source 102 is embodied as a light-emitting reflector. In this way, the second light source 102 can serve on the one hand as a reflector for the light emitted by the first light source 101 and, on the other hand, the second light source 102 can be used as an area light source separate from the first light source 101. To this end, the second light source 102 comprises a reflective layer 1 with a reflective surface 11 facing the first light source 101 for its reflection properties and an electroluminescent layer sequence 10 for its light emission properties. Detailed configurations of the second light source 102 are described in relation to FIGS. 2 and 3.

[0032] Depending on the application of the lamp 100, for example, as a motor vehicle headlamp, a torch or a head torch, the second light source 102 embodied as a light-emitting reflector can be embodied as a collimator or be only partly collimating or indeed non-collimating in relation to the first light source 101. If the second light source 102 is embodied as a collimating light-emitting reflector, the first light source 101 can be located in a focal point of the light-emitting reflector.

[0033] For example, the second light source 102 embodied as a light-emitting reflector and thus in particular the reflective surface 11 of the reflective layer 1 can be embodied at least in part as an elliptical paraboloid, at least in part as a rotational paraboloid, at least in part as part of an ellipsoid or a sphere or indeed as a freeform surface.

[0034] The second light source 102 can be rigid or deformable. If the second light source 102 and thus in particular the reflective layer 1 is deformable, the shape of the reflective surface 11 of the reflective layer 1 can be modified, such that the light path can be modified in relation to the light of the first light source 101, so making different emission patterns possible. In the case of a motor vehicle headlamp, an adaptive front-lighting system or a fog light can be achieved thereby, for example.

[0035] FIG. 2 shows an exemplary embodiment of a second light source 102 comprising a reflective layer 1 with a reflective surface 11 and an electroluminescent layer sequence 10. In the exemplary embodiment shown, the reflective layer 1 is embodied as part of the electroluminescent layer sequence 10.

[0036] In the exemplary embodiment shown, the electroluminescent layer sequence 10 comprises an organic functional layer stack 3 on the reflective surface 11 of reflective layer 1, said stack having at least one organic light-emitting layer 4 arranged between the reflective layer 1 as first electrode and a transparent further electrode 2. The reflective layer 1 can serve as a carrier layer and thus as a substrate for the further layers applied thereto. Alternatively, it can also be possible for the reflective layer 1 to be applied in the form of a coating to an additional substrate, not shown here, which can, for example, comprise one or more of the following materials: glass, plastics, metal, semiconductor material, ceramics.

[0037] The electroluminescent layer sequence 10 and thus the second light source 102 embodied as a light-emitting reflector is embodied in particular as an organic light-emitting diode (OLED) which, when in operation, emits light through the transparent electrode 2 in the direction of the first light source and in particular into the surrounding environment. The organic functional layer stack 3 can comprise layers with organic polymers, organic oligomers, organic monomers, organic small, non-polymeric molecules (small molecules) or combinations thereof. Materials suitable for the organic light-emitting layer 4 are materials which have radiation emission based on fluorescence or phosphorescence, for example, polyfluorene, polythiophene or polyphenylene, or derivatives, compounds, mixtures or copolymers thereof. The organic functional layer stack 3 can comprise, in addition to the at least one organic light-emitting layer 4, charge carrier transport layers and/or charge carrier blocking layers such as for instance hole transport layers, electrode transport layers, hole blocking layers, electron blocking layers and further organic functional layers.

[0038] The reflective layer 1 embodied as an electrode of the electroluminescent layer sequence 10 comprises a metal, which can be selected from aluminum, barium, indium, silver, gold, magnesium, calcium and lithium as well as compounds, combinations and alloys. In particular, the reflective layer 1 can comprise Ag, Al or alloys therewith, for example, Ag:Mg, Ag:Ca, Mg:Al.

[0039] The transparent electrode 2 can, for example, comprise a transparent conductive oxide (TCO). TCOs are transparent conductive materials, generally metal oxides such as, for example, zinc oxide, tin oxide, cadmium oxide, titanium oxide, indium oxide, indium tin oxide (ITO) or aluminum zinc oxide (AZO). In addition to binary metal-oxygen compounds, such as, for example, ZnO, SnO.sub.2 or In.sub.2O.sub.3, ternary metal-oxygen compounds, such as, for example, Zn.sub.2SnO.sub.4, CdSnO.sub.3, ZnSnO.sub.3, MgIn.sub.2O.sub.4, GaInO.sub.3, Zn.sub.2In.sub.2O.sub.5 or In.sub.4Sn.sub.3O.sub.12 or mixtures of different transparent conductive oxides also belong to the TCO group. Furthermore, TCOs do not necessarily correspond to a stoichiometric composition and can also be p- or n-doped. Furthermore, the transparent electrode 2 can comprise a metal layer with a metal or an alloy, for example, with one or more of the following materials: Ag, Pt, Au, Mg, Ag:Mg. The metal layer in this case exhibits a thickness which is small enough to be at least partly transmissive to light, for example, a thickness of less than or equal to 50 nm or less than or equal to 20 nm. Furthermore, the transparent electrode 2 can comprise or consist of silver nano wires (SNW). Furthermore, the transparent electrode 2 can also comprise or consist of a metal grid combined with a highly conductive hole injection layer or a conductive polymer. The transparent electrode 2 can also comprise or consist of a combination of layers with the stated materials.

[0040] In the exemplary embodiment shown, when viewed from the reflective layer 1 an encapsulation 5 is further applied over the organic functional layer stack 3 and the electrode 2 which is suitable for forming a barrier relative to atmospheric substances, in particular relative to moisture and oxygen and/or relative to further harmful substances such as for instance corrosive gases, for example, hydrogen sulfide. Particularly preferably, the encapsulation 5 can take the form of thin-film encapsulation. The encapsulation 5 can to this end comprise one or more layers each with a thickness of less than or equal to a few 100 nm. In particular, the thin-film encapsulation can comprise or consist of thin layers which are applied, for example, by means of an atomic layer deposition (ALD) method. Suitable materials for the layers of the encapsulation 5 are, for example, aluminum oxide, zinc oxide, zirconium oxide, titanium oxide, hafnium oxide, lanthanum oxide or tantalum oxide. The encapsulation 5 can, for example, comprise a layer sequence with a plurality of the thin layers which each comprise a thickness of between one atomic layer and 10 nm, limit values included. As an alternative or in addition to thin layers produced by ALD, the encapsulation 5 can comprise at least one or a plurality of further layers, i.e., in particular barrier layers and/or passivation layers, which are deposited by thermal vapor deposition or by a plasma-enhanced process, for instance sputtering or plasma-enhanced chemical vapor deposition (PECVD). Suitable materials for this purpose can be the above-stated materials together with silicon nitride, silicon oxide, silicon oxynitride, indium tin oxide, indium zinc oxide, aluminum-doped zinc oxide, aluminum oxide and mixtures and alloys of the stated materials. The one or more further layers can, for example, each have a thickness of between 1 nm and 5 ?m and preferably between 1 nm and 400 nm, limit values included.

[0041] By selecting suitable materials, in particular with regard to the reflective layer 1 and optionally an additional substrate, the second light source 102 can be rigid or indeed flexible and thus deformable. The reflective layer 1 can thus, for example, be formed by a flexible metal foil, which serves at the same time as a substrate for the further layers. Furthermore, it is also conceivable for the reflective layer 1 to be applied in the form of a metal layer to a substrate in the form of a plastics film or an at least partly deformable glass film.

[0042] FIG. 3 shows a further exemplary embodiment of a second light source 102 which, compared with the previous exemplary embodiment, comprises an electroluminescent layer sequence 10 with a transparent substrate 6 to which are applied the transparent electrode 2, the organic functional layer stack 3, the reflective layer 1 as further electrode and the encapsulation 5.

[0043] The electroluminescent layer sequence 10 can be manufactured separately as a flexible layer sequence and is applied to a carrier 7 by the encapsulation side. The carrier 7, which can, for example, comprise a plastics material and/or a metal, can in this case form the basic shape of the light-emitting reflector, which is coated with the electroluminescent layer sequence 10 and thus in particular also with the reflective layer 1.

[0044] Alternatively, it can also be possible for the reflective layer of the second light source 102 to be formed by the carrier 7. In this case, the electroluminescent layer sequence 10 comprises a transparent electrode between the organic functional layer stack 3 and the encapsulation 5.

[0045] FIG. 4 shows a further exemplary embodiment of a lamp 100 which can be configured according to the previous exemplary embodiments. In comparison with the exemplary embodiment of FIG. 1, the lamp 100 of the exemplary embodiment of FIG. 4 additionally comprises an exit face 103, via which the light generated respectively by the first light source 101 and the second light source 102 when in operation is emitted. The exit face 103 can, for example, be formed by a glass window.

[0046] While the emission pattern of the light generated by the first light source 101 is determined and, for example, directed by the shape of the second light source 102 embodied as a light-emitting reflector, the emission pattern of the light generated by the second light source 102 corresponds substantially to a Lambertian emission pattern at the exit face 103. In this way, the brightness of the exit face 103 when the second light source 102 is in operation is perceived as the same from all directions of view onto the exit face 103, two of which directions of view 90, 91 are shown by way of example in FIG. 4, since the luminance remains constant. Only the visible luminous area changes.

[0047] In this way, the lamp 100 can, for example, be suitable as a motor vehicle headlamp, in which the first light source 101 can, for example, have the function of a low-beam and/or high-beam headlamp, while the second light source 102 is ideal for providing a daytime running light.

[0048] FIGS. 5A and 5B show a lamp 100 embodied accordingly as a motor vehicle headlamp, with the view directed onto the exit face 103 formed by a headlamp glass. The position of the second light source 102 is indicated by the correspondingly labeled region, while the first light source, which is located inside the lamp 100, is not shown for clarity's sake.

[0049] FIG. 5A shows the lamp 100 with its second light source 102 switched off, the second light source 102 merely adopting the function of a reflector for the first light source. In FIG. 5B, on the other hand, the lamp 100 is indicated with its second light source 102 switched on and thus with a luminous reflector, forming a daytime running light which merges with the design of the headlamp.

[0050] FIGS. 6A and 6B show a lamp 100 according to a further exemplary embodiment, which can, for example, take the form of a torch or head torch. FIG. 6A shows an operating state of the lamp 100 in which the first light source is being operated. The corresponding emission pattern is indicated by means of the beams of light 99. When the first light source is in operation, a high-beam function is thus enabled, for example, for illuminating a remote object. The light of the first light source is directed into the distance via the reflective layer of the second light source and can exit the lamp 100 in parallel or with slight widening.

[0051] FIG. 6B shows an operating state of the lamp 100 in which the second light source is being operated. The corresponding emission pattern is again indicated by means of the beams of light 99. Operation of the second light source allows diffuse and uniform illumination of the surrounding environment, such that the lamp 100 can be used in this operating state, for example, as a reading light or as a safety light for near-field illumination, allowing better visibility.

[0052] In a further operating state, both light sources can also be operated simultaneously, such that the emission patterns indicated in FIGS. 6A and 6B are superimposed. In this way, a strong beam of light produced by the first light source is able to provide distance illumination, while the second light source provides close range lighting.

[0053] The exemplary embodiments described in the figures can additionally or alternatively comprise further features according to the embodiments described above in the general part of the description.

[0054] The description made with reference to exemplary embodiments does not restrict the invention to these embodiments. Rather, the invention encompasses any novel feature and any combination of features, including in particular any combination of features in the claims, even if this feature or this combination is not itself explicitly indicated in the claims or exemplary embodiments.