Lamp for general lighting

Abstract

A lamp includes a lamp housing which has a light exit opening. A light source of a first type is arranged in the lamp housing. A mounting is fastened to the lamp housing and at least one light source of a second type is fastened to the holder. The at least one light source of the second type includes an organic light-emitting diode and the at least one light source of the second type is arranged downstream of the light exit opening in an emission direction.

Claims

1. A lamp comprising: a lamp housing, which has a light exit opening; a light source of a first type arranged in the lamp housing; a lampholder fastened on the lamp housing; and a light source of a second type fastened on the lampholder, the light source of the second type comprising an organic light-emitting diode, and the light source of the second type arranged downstream of the light exit opening in an emission direction, wherein the lamp housing has a first cavity designed as an ellipsoid of revolution, in some places, the light source of the first type being arranged in a vicinity of one focal point of the ellipsoid of revolution that is remote from the light exit opening, and wherein the light exit opening is arranged in a vicinity of another focal point of the ellipsoid of revolution.

2. The lamp according to claim 1, wherein the light source of the second type is designed to be reflective, at least in some places, and light emitted during operation of the light source of the first type impinges on and is reflected by the light source of the second type.

3. The lamp according to claim 1, wherein the light source of the second type is designed to be transmissive to radiation, at least in some places, and light emitted during operation of the light source of the first type impinges on and radiates through the light source of the second type.

4. The lamp according to claim 1, wherein the lamp housing has a first cavity, in which the light source of the first type is arranged, wherein an inner face of the first cavity facing the light source of the first type, is reflective.

5. The lamp according to claim 1, wherein the first cavity is designed in the manner of an ellipsoid which is cut away in the region of its focal planes along the focal planes.

6. The lamp according to claim 1, wherein the lamp housing has a second cavity arranged on a side of the first cavity remote from the light exit opening.

7. The lamp according to claim 1, wherein the lamp housing has a basic body in the form of a truncated cone or a truncated pyramid, at least in some places, wherein the truncated cone or the truncated pyramid tapers in a direction opposite to a direction of the light exit opening.

8. The lamp according to claim 1, wherein the lamp housing has a basic body and at least two cooling disks and/or cooling ribs, the cooling disks and/or the cooling ribs being fastened on the basic body spaced apart from one another and surrounding the basic body laterally.

9. The lamp according to claim 7, wherein an outer face of the lamp housing that surrounds the light exit opening is reflective, at least in some places.

10. The lamp according to claim 1, wherein the lampholder is used for electrically connecting the light source of the second type.

11. The lamp according to claim 1, wherein the light source of the second type is mounted rotatably.

12. The lamp according to claim 11, wherein the lampholder comprises at least two rods, between which the light source of the second type is mounted rotatably.

13. The lamp according to claim 1, wherein the lampholder comprises at least one rod in the shape of a sinusoidal function, at least in some places.

14. The lamp according to claim 1, wherein the lampholder comprises first and second rods, a profile of the second rod proceeding from a profile of the first rod and a rotation about the main axis of extent of the first rod.

15. The lamp according to claim 1, wherein the lampholder is designed in the manner of a two-start screw, the lampholder comprising two rods, which are each in the form of a helix.

16. The lamp according to claim 6, further comprising a drive apparatus arranged in the second cavity, the drive apparatus configured to drive the light sources.

17. The lamp according to claim 1, further comprising a further light source of the second type arranged downstream of the light exit opening in the emission direction.

18. The lamp according to claim 17, wherein the lampholder comprises at least two rods, between which the light source of the second type and the second light source of the second type are mounted rotatably.

19. A lamp comprising: a lamp housing, which has a light exit opening; a light source of a first type arranged in the lamp housing; a lampholder fastened on the lamp housing; a light source of a second type fastened on the lampholder the light source of the second type comprising an organic light-emitting diode, and the light source of the second type arranged downstream of the light exit opening in an emission direction, wherein the lampholder comprises first and second rods, a profile of the second rod proceeding from a profile of the first rod and a rotation about the main axis of extent of the first rod.

20. The lamp according to claim 19, wherein the first and the second rods follow the shape of a sinusoidal function, at least in some places.

21. The lamp according to claim 19, wherein the first and the second rods follow each the form of a helix.

22. A lamp comprising: a lamp housing, which has a light exit opening; a light source of a first type arranged in the lamp housing; a lampholder fastened on the lamp housing; a light source of a second type fastened on the lampholder the light source of the second type comprising an organic light-emitting diode, and the light source of the second type arranged downstream of the light exit opening in an emission direction, wherein the second type is reflective, at least in some places, and light emitted during operation of the light source of the first type impinges on and is reflected by the light source of the second type.

23. The lamp according to claim 22, wherein the light source of the second type is reflective on a rear side of the light source of the second type remote from an emission side of the light source of the second type.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The lamp described here will be described in more detail below with reference to exemplary embodiments and the associated figures.

(2) FIGS. 1A, 1B, 1C show schematic illustrations of lamp housings for exemplary embodiments of a lamp described here;

(3) FIGS. 2A, 2B, 2C, 2D, 2E, 2F show light sources of a first type that are explained in more detail for exemplary embodiments of lamps described here;

(4) FIG. 3 shows a lampholder for an exemplary embodiment of a lamp described here and explained in more detail; and

(5) FIGS. 4A and 4B show an exemplary embodiment of a lamp described here and explained in more detail.

(6) Identical, similar or functionally identical elements have been provided with the same reference symbols in the figures. The figures and the size ratios of the elements illustrated in the figures with respect to one another should not be considered as being to scale. In fact individual elements may be illustrated as being excessively large to improve illustration and/or understanding.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

(7) FIG. 1A shows a schematic sectional illustration of a lamp housing for an exemplary embodiment of a lamp described here. The lamp housing 1 comprises a basic body 11. The basic body 11 is formed with a metal, for example. The basic body 11 is formed in the manner of a truncated cone, in a first section, and in the manner of a cylinder in a second section.

(8) The basic body 11 comprises cooling disks 14a, which are cylindrical and are fastened on the basic body, spaced apart from one another in a vertical direction. For example, the cooling disks 14a are designed to be integral with the basic body 11. The cooling disks 14a increase the outer surface area of the basic body 11 and therefore the lamp housing 1 and, therefore, serve to dissipate heat generated during operation of the lamp. The cooling disks 14a can surround the basic body 11 laterally in this case, in each case completely in the form of rings.

(9) As a deviation from the exemplary embodiment illustrated in FIG. 1A, it is also possible for cooling ribs 14b to be fastened on the basic body 11, spaced apart radially, and for said cooling ribs to extend in the vertical direction (see the schematic perspective illustration in FIG. 1C). The cooling ribs 14b can in this case each be rectangular, for example. A combination of cooling ribs 14b and cooling disks 14a is also possible.

(10) Furthermore, the basic body 11 comprises a first cavity 13. The first cavity 13 has an inner wall 131, which is designed to be reflective for visible light. The inner wall 131 of the first hollow body 13 is in the form of an ellipsoid of revolution, at least in some places. The ellipsoid of revolution has a first focal point 132 and a second focal point 133. The hollow body 13 is open on its longitudinal sides, i.e., in the region of the focal points 132, 133. The light source of the first type 2 is arranged at the first focal point 132. For example, a light exit opening of the light source 2 lies in the same plane as the first focal point 132.

(11) The light exit opening 12, which is formed, for example, by an opening in the basic body 11 which can be covered by a piece of glass, is located at the second focal point 133. A plane which terminates the light exit opening 12 also comprises the second focal point 133, for example.

(12) The light exit opening 12 has a diameter d, with this being the maximum diameter of the light exit opening, for example. The diameter d is in the range of between 25 mm and 35 mm, in this case 30 mm, for example.

(13) The light source 2 comprises a heat sink 21 and light-emitting diode chips 22, 23 (see FIGS. 2A to 2F in this regard). Electromagnetic radiation generated during operation of the light source of the first type 2 is reflected on the inner walls 131 of the first cavity 13 in the direction of the light exit opening 12 and passes to the outside there.

(14) As a deviation from this, it is also possible for the inner walls 131 to be designed to be non-reflective. The light source of the first type 2 may then be a light module which itself comprises an optical element for beam shaping and/or beam guidance, for example. The first cavity 13 is then a container which accommodates the light module.

(15) The outer face 16 of the basic body 11 which surrounds the light exit opening 12 can be designed to be reflective. The width of the lamp housing B is between 110 mm and 130 mm, in this case 120 mm, for example. The height H1 of the lamp housing 1, i.e., the distance between the outer face 16 and that face of the lamp housing 1 which is opposite the outer face, is between 250 mm and 270 mm, in this case 260 mm, for example.

(16) The basic body 11 of the lamp housing 1 has a second cavity 15. For example, a drive apparatus 5 for electrically operating and driving the light sources of the lamp can be provided in the second cavity 15.

(17) In conjunction with the schematic sectional illustration in FIG. 1B, a lamp housing 1 for a further exemplary embodiment of a lamp described here will be explained in more detail. In this exemplary embodiment, the entire basic body 11 is in the form of a truncated cone which tapers in the opposite direction to the direction of the light exit opening 12. In conjunction with FIG. 1B, the design of the first cavity 13 in the form of an ellipsoid of revolution is also described in more detail. The ellipsoid of revolution has the axes a, b, which are selected to have a ratio of 2:1, for example. The ratio of the focal distance f in relation to the small axis b is then approximately 1.73:1. The eccentricity of the ellipsoid of revolution is then e=0.866.

(18) Owing to the choice of the cavity 13 with its reflective inner wall 131 in the form of an ellipsoid, the light from the light source 2 is mixed particularly well before the light exit through the light exit opening 12. In addition, the light exit opening 12, which is arranged in the region of the second focal point 133, can be selected to be relatively small. For example, the maximum diameter d of the light exit opening 12 is at most twice as great as the maximum diameter d2 of the light exit face of the light source of the first type 2.

(19) FIG. 2A shows a schematic plan view of a light source of the first type 2, as is used in an exemplary embodiment of a lamp described here. The light source 2 comprises four first light-emitting diode chips 22 and three second light-emitting diode chips 23.

(20) The schematic plan view in FIG. 2B shows an alternative light source 2 with in each case four first light-emitting diode chips 22 and four second light-emitting diode chips 23. For example, the light source of the first type 2 can comprise eight light-emitting diode chips, for example, four light-emitting diode chips 23 emitting red light and four light-emitting diode chips 22 emitting green-blue light. It is also conceivable for the light source of the first type 2 to comprise seven light-emitting diode chips, for example, two light-emitting diode chips emitting red light, two light-emitting diode chips emitting amber-colored light and three light-emitting diode chips emitting blue-green light.

(21) The light source of the first type 2 is operated with a current of 700 mA, for example, and generates waste heat of at least 10 W, for example approximately 15 W. The lamp housing 1 is suitable for dissipating this waste heat, for example, owing to the cooling rings 14b on the basic body 11.

(22) In FIGS. 2C to 2F, spectra are plotted graphically in each case, with the intensity I in arbitrary units being plotted against the wavelength λ in nm.

(23) FIG. 2C shows, plotted graphically, the spectrum of second light-emitting diode chips 23, which have a peak wavelength λP in the region of red light. FIGS. 2D and 2E show two possibilities for the first light-emitting diode chips 22, which each have peak wavelengths in the region of blue light λP1 and green light λP2. FIG. 2F shows a resultant spectrum, for example, given the combination of light-emitting diode chips 22, 23 which are arranged as shown in FIG. 2B and have the spectra in FIGS. 2C and 2D. The color rendering index Ra of such a light source of the first type 2 is approximately 86. Preferably, the light emitted by the light source of the first type 2 has a color rendering index Ra of at least 80. The color temperature of the light emitted by the light source of the first type 2 is at least 2700 K, in this case approximately 2950 K, for example.

(24) In the spectrum shown in FIG. 2F, the peak wavelengths λP1, λP2, λP of the two types of light-emitting diode chips 22, 23 are shown.

(25) In order to achieve a desired color locus and/or a desired color temperature of the light emitted by the lamp, however, other light-emitting diodes and light sources of the first type other than those described can also be used.

(26) In conjunction with FIG. 3, a lampholder for an exemplary embodiment of a lamp described here is explained in more detail with reference to a schematic perspective illustration. FIG. 3 shows a lampholder 4, which comprises two rods 41, 42, which extend along their main axis of extent z. The two rods 41, 42 are each in the form of a helix. In this case, the rod 42 proceeds from the rod 41 by a rotation through 180° about the main axis of extent z, for example. The profile of the rod 41 may be described functionally as follows, for example: x=sin(t), y=cos(t), z=t. Overall, the lampholder 4 forms a two-start screw, which is formed by two helices 41, 42.

(27) In conjunction with the schematic perspective illustration in FIG. 4A, it is demonstrated that the lampholder 4 is fastened mechanically on the lamp housing 1. The rods 41, 42 wind in this way around the main emission direction R of the light source of the first type 2, which runs parallel to the main axis of extent z of the rods 41, 42.

(28) In conjunction with the schematic perspective illustration shown in FIG. 4B, an exemplary embodiment of a lamp described here is explained in more detail. The lamp housing 1 with the light exit opening 12 surrounds the lamp. The lampholder 4, which is in the form of a two-start screw, is fastened mechanically on the lamp housing 1. The rods 41, 42 of the lampholder 4 act as power supply lines for the light sources of the second type 3.

(29) The lamp comprises six light sources of the second type, which are each formed by organic light-emitting diodes, for example. In this case, the light sources of the second type 3 comprise an emission side 31, from which electromagnetic radiation is emitted actively from the light sources of the second type 3. For example, the light sources of the second type 3 emit white light at a color temperature of between 2700 K and 2900 K, in this case 2800 K. The light sources of the second type 3 also comprise a rear side 32, which is remote from the emission side and is in this case reflective. The emission side 31 can also be designed to be reflective, with the result that the light sources of the second type 3 reflect light from the light source of the first type 2 which exits through the light exit opening 12 in the lamp housing 1.

(30) The light sources of the second type 3 are mounted rotatably about the rotary spindles 6 and are fastened on both rods 41, 42 of the lampholder 4. Owing to the embodiment of the lampholder 4 in the form of a two-start screw, given a suitable arrangement of the light sources of the second type 3, light from the light source of the first type 2 can pass to each light source of the second type 3.

(31) The height H2 of the lampholder is in this case at least 200 mm, for example 920 mm. The arrangement of the light sources of the second type 3 between the rods 41, 42 of the lampholder 4 also results in mechanical stabilization of the lampholder 4. By rotation about the rotary spindles 6 of the light sources of the second type 3, an emission characteristic of the lamp can be adjusted relatively freely. An adjustment of the color temperature and/or the color locus of the emitted light can also be performed by virtue of driving the light sources of the second type 3 and the light source of the first type 2. For example, it is thus possible to generate white light in the warm-white and cold-white region by means of the lamp.

(32) Owing to the fact that the light from the light source of the first type 2 radiates onto the light sources of the second type 3, the light sources of the second type 3 appear to be overall brighter. This gives the impression that the overall emitted light from the lamp originates from the light sources of the second type 3.

(33) In addition to the exemplary embodiment shown in FIG. 4B, in which the light sources of the second type 3 are designed to be reflective, at least in some places, it is also possible for the light sources of the second type 3 to be designed to be transmissive to radiation and to emit electromagnetic radiation both from their front side 31 and from their rear side 32. The light from the light source of the first type 2 then radiates through the light sources of the second type 3. This also gives the impression that the overall light generated by the lamp during operation originates from the light sources of the second type 3.

(34) The invention is not restricted to the exemplary embodiments by the description with reference to the exemplary embodiments to. Instead, the invention includes any novel feature and any combination of features, which includes in particular any combination of features in the patent claims, even if this feature or this combination itself is not explicitly mentioned in the patent claims or exemplary embodiments.