Illumination unit having an antifogging system

Abstract

The disclosure relates to an illumination unit, in particular an elongated illumination unit, on the outside of a motor vehicle, comprising a housing having at least one light emission opening which is closed by a light-transmissive cover plate, wherein the housing has two end regions, arranged in which in each case is an illumination assembly having at least one light source that is designed to emit light through the cover plate. In a rear housing wall, i.e., in a rear wall of the housing, between the two end illumination assemblies are arranged at least one air inlet opening and, separate therefrom, at least one air outlet opening, wherein the air inlet opening is connected to the vehicle interior of the motor vehicle, whereas the air outlet opening is connected to an outer area of the motor vehicle. This establishes during operation of the motor vehicle an automatic air circulation in the interior of the housing from the air inlet opening to the air outlet opening that is brought about by a pressure difference between vehicle interior and outer area of the motor vehicle.

Claims

1. An illumination unit for a motor vehicle, comprising: a housing including a first end region having a first illumination assembly and a second end region having a second illumination assembly; an air inlet opening formed in a rear housing wall of the housing between the first illumination assembly and the second illumination assembly; and an air outlet opening formed in the rear housing wall of the housing between the first illumination assembly and the second illumination assembly, wherein the air inlet opening is connected to a vehicle interior of the motor vehicle and the air outlet opening is connected to an outer area of the motor vehicle, thereby establishing an automatic air circulation achieved by a pressure difference between the vehicle interior and the outer area.

2. The illumination unit as recited in claim 1, wherein the housing includes a light emission opening closed by a light-transmissive cover plate, and further wherein the first illumination assembly and the second illumination assembly are configured to emit light through the light-transmissive cover plate.

3. The illumination unit as recited in claim 2, wherein the light-transmissive cover plate is located on an opposite side of the housing from the rear housing wall.

4. The illumination unit as recited in claim 1, wherein the illumination unit is an elongated illumination unit that is mounted to a tailgate of the motor vehicle.

5. The illumination unit as recited in claim 4, wherein the elongated illumination unit is a coast-to-coast illumination unit that extends over an entire width of the tailgate.

6. The illumination unit as recited in claim 1, wherein the pressure difference between the vehicle interior and the outer area of the motor vehicle is achieved by an operation of an air conditioning system of the motor vehicle and/or a forward motion of the motor vehicle.

7. The illumination unit as recited in claim 6, wherein the pressure difference is at least 20 Pa.

8. The illumination unit as recited in claim 1, wherein the air inlet opening and the air outlet opening are vertically offset in a Z-direction of the motor vehicle, and further wherein the air inlet opening is vertically higher than the air outlet opening in the Z-direction of the motor vehicle.

9. The illumination unit as recited in claim 1, comprising a ventilation element disposed within each of the air inlet opening and the air outlet opening.

10. The illumination unit as recited in claim 1, wherein the first end region is located adjacent to a first taillight of the motor vehicle, and the second end region is located adjacent to a second taillight of the motor vehicle.

11. The illumination unit as recited in claim 1, wherein the first illumination assembly and the second illumination assembly are each configured to function as a taillight, a rear fog light, and/or a reversing light.

12. An illumination unit for a motor vehicle, comprising: a housing including a first end region having a first illumination assembly and a second end region having a second illumination assembly; an air inlet opening formed in a rear housing wall of the housing between the first illumination assembly and the second illumination assembly; an air outlet opening formed in the rear housing wall of the housing between the first illumination assembly and the second illumination assembly, wherein the air inlet opening is connected to a vehicle interior of the motor vehicle and the air outlet opening is connected to an outer area of the motor vehicle, thereby establishing an automatic air circulation achieved by a pressure difference between the vehicle interior and the outer area; and a third illumination assembly arranged within the housing between the first illumination assembly and the second illumination assembly.

13. The illumination unit as recited in claim 12, wherein the automatic air circulation extends past the third illumination assembly.

14. The illumination unit as recited in claim 12, wherein the third illumination assembly is located between the air inlet opening and the air outlet opening.

15. The illumination unit as recited in claim 12, wherein the third illumination assembly includes an LED light band and/or an illuminated lettering.

16. An illumination unit for a motor vehicle, comprising: a tailgate; an elongated illumination housing mounted to the tailgate and including a first illumination assembly and a second illumination assembly; an air inlet opening formed in a rear housing wall of the elongated illumination housing at a location between the first illumination assembly and the second illumination assembly; and an air outlet opening formed in the rear housing wall at a location between the first illumination assembly and the second illumination assembly.

17. The illumination unit as recited in claim 16, wherein the air inlet opening is connected to a vehicle interior of the motor vehicle and the air outlet opening is connected to an outer area of the motor vehicle, thereby establishing an automatic air circulation achieved by a pressure difference between the vehicle interior and the outer area.

18. The illumination unit as recited in claim 17, comprising a third illumination assembly arranged within the elongated illumination housing between the first illumination assembly and the second illumination assembly, wherein the automatic air circulation extends past the third illumination assembly.

19. The illumination unit as recited in claim 16, wherein the elongated illumination housing extends across an entire width of the tailgate.

20. The illumination unit as recited in claim 16, wherein a first end region of the elongated illumination housing is located adjacent to a first taillight of the motor vehicle, and a second end region of the elongated illumination housing is located adjacent to a second taillight of the motor vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantageous refinements of the invention are disclosed in the subclaims and in the following description of the figures. In the figures:

(2) FIG. 1 shows a three-dimensional view of one embodiment of the illumination unit according to the unit from the back,

(3) FIG. 2 shows a front view of the illumination unit according to FIG. 1, and

(4) FIG. 3 shows a rear view of the illumination unit according to FIG. 1.

(5) In the different figures, identical parts are always provided with the same reference signs, for which reason these parts are generally also described only once.

DETAILED DESCRIPTION

(6) FIG. 1 shows one possible embodiment of an elongated illumination unit 10 according to the disclosure in a three-dimensional view. Here, the illumination unit 10 is shown from the back, via which it is mounted on a motor vehicle. It is, for example, a tailgate illumination unit which preferably extends over the entire tailgate of a motor vehicle, i.e. a so-called coast-to-coast illumination unit is shown here. The motor vehicle and further illumination assemblies thereon are not illustrated; however, for example, the two ends of the illumination unit 10 in the installed state are adjacent to further illumination assemblies of the motor vehicle, which can be in particular rear illuminations, for example taillights, reversing lights and/or turn signals. This is shown schematically in FIG. 2.

(7) The illumination unit 10 has an elongated housing 30 which forms in particular the outer contour of the illumination unit 10. The housing 30 has a rear housing wall 32 which acts as a rear wall on the back. On the rear wall, the housing 30 has in particular means for electrical connection of the illumination unit 10 to the electrical system of the motor vehicle; they are, however, only shown exemplarily in the exemplary embodiment of FIG. 1. Furthermore, exemplary means for fastening the illumination unit 10 are also shown. Formed on the side opposite to the rear wall, i.e. on the front of the illumination unit 10, is an elongated light emission opening which is closed by a light-transmissive cover plate 31. The light emission opening can extend in the y-direction over the entire housing 30 and can be closed by the light-transmissive cover plate 31. The tailgate illumination unit 10 is then transparent over its entire width and can contain various light sources.

(8) Arranged in the interior of the housing 30 are, for example, at least two illumination assemblies 20 and 21, these being respectively arranged in the end regions of the housing 30. Light emitted by the illumination assemblies is radiated rearward and is emitted from the housing 30 through the cover plate 31. Each illumination assembly 20, 21 forms, for example, a taillight, a rear fog light and/or a reversing light. These are also shown only schematically in FIG. 2.

(9) The two end illumination assemblies 20, 21 are formed in a known manner and include, for example, one or more light-emitting diodes and a reflector as the light source. Furthermore, apertures and/or lenses may be provided in this region. Provided between the illumination assemblies 20, 21 in the rear wall of the housing 30 is at least one air inlet opening 40. Separate therefrom, an air outlet opening 41 is furthermore likewise provided between the two illumination assemblies 20, 21. The air inlet opening 40 is connected to the vehicle interior of the motor vehicle, which is identified by reference sign 60 in FIG. 1. By contrast, the air outlet opening 41 is connected to the outer area of the illumination unit 10, and the outer area is identified by reference sign 70.

(10) Owing to a positive pressure in the vehicle interior 60, air, which can also be referred to as air inlet flow 51, flows through the air inlet opening 40 into the interior of the housing 30. What forms there is an air flow 50 or air circulation, which flows in particular through the central region of the housing 30 and leaves the housing again via the air outlet opening 41 and flows into the outer area 70. This air flow into the outer area 70 is also referred to as air outlet flow 52. The course of the air flow 50 is merely indicated in basic idealized form without any turbulence. Suitable guide structures not shown in the figures make it possible to achieve, by way of example, the course of the air flow 50 as shown in FIGS. 1 and 2.

(11) The air inlet opening 40 may be connected to the vehicle interior 60 via various ducts and/or hoses in order to bring about the air inlet flow 51 owing to the positive pressure in the vehicle interior 60. The same applies to the air outlet opening 41, which for example is connected to a hose in order to guide the air outlet flow 52 at a suitable point into the outer area 70.

(12) The positive pressure in the vehicle interior 60 may be achieved in various ways, and according to one embodiment, it is produced by operation of the motor vehicle. To this end, the windows and doors of the motor vehicle are ideally closed. The operation of an air conditioning system in the vehicle interior 60, for example, then produces the positive pressure in the vehicle interior. This has the advantage that the supplied air is also dry and heated. Alternatively, or additionally, forward motion of the motor vehicle also produces the positive pressure. The positive pressure causes a pressure difference between vehicle interior 60 and outer area 70 that leads to the aforementioned air flows. To this end, there is no need to provide further components such as fans, blowers, heaters, etc., in order to convey air into the housing 30; instead, the air circulation occurs automatically.

(13) In one embodiment of the disclosure, at least one further illumination assembly 22 is provided in the central region of the illumination unit 10. This is, for example, an LED light band, illuminated lettering or some other light element provided within the illumination unit 10 for illumination reasons. The illumination assembly 22 lies between the two openings 40 and 41, and the supplied air particularly effectively demists the cover plate 31 in this region as well, in the event of fogging of the cover plate 31. But also possible fogging in the region of the end illumination assemblies 20 and 21 is effectively prevented or dispersed by the generated air circulation, since the supplied air flow brings about an air circulation right into the regions, though this is not shown in the figures.

(14) In order to prevent or disperse fogging as effectively as possible, what is therefore realized is an air circulation that is as extensive as possible. The openings 40 and 41 are suitably designed and arranged for this purpose.

(15) FIG. 2 shows schematically, for example, the front of an illumination unit 10 having the two illumination assemblies 20 and 21 on the left and right of the drawing plane. The illumination assemblies 20, 21 in the installed state are adjacent to further illumination assemblies of the motor vehicle, which are however shown only in dashed form in FIG. 2 in order to illustrate their position. FIG. 2 is a schematic view through the cover plate 31 to the rear wall of the housing 30, formed in which are the air inlet opening 40 and, separate therefrom, the air outlet opening 41. The openings lie between the two illumination assemblies 20 and 21, and the distance y between them in the y-direction of the motor vehicle is chosen as greatly as possible, but with account being taken of the other fittings in the housing 30. The distance is thus maximal taking into account these other components, i.e. if further components are required between the two illumination assemblies 20, 21, the former are suitably positioned and the remaining space is used to arrange the openings 40 and 41 at the greatest possible distance y to each other. The same applies to a height difference z between the two openings 40 and 41 in the z-direction. The indicated directions correspond to the customary vehicle coordinate system x, y, z.

(16) FIG. 2 also shows the basic course of a resultant air flow 50 within the housing 30. Although it does not flow directly along the illumination assemblies 20 and 21, it does generate an air circulation throughout the housing 30 that is capable of also removing fogging from the two illumination assemblies 20, 21 or preventing fogging thereof. Furthermore, a possible central illumination assembly 22 is indicated, in the region of which fogging can also be prevented or dispersed.

(17) FIG. 3 shows the illumination unit 10 again from the back, which is mounted on the motor vehicle. What can be seen again is the rear housing wall 32, i.e. the rear wall having the air inlet opening 40, which is at a higher level in relation to the air outlet opening 41, and the lower-level air outlet opening 41. On this side, the air inlet flow 51 and the air outlet flow 52 also enter and exit through the openings in the rear wall of the housing 30, the air flow 50 coursing within the housing 30 being shown in the form of dashes. As can be seen, the course of the air flow 50 shown in the form of dashes in FIG. 3 is different from that in FIGS. 1 and 2, and this is achievable by corresponding guide structures.

(18) Ventilation elements having membranes, which are not shown, may be arranged at the air inlet opening 40 and at the air outlet opening 41, and they allow a continuous air flow, but prevent or reduce the ingress of moisture and dirt. The ventilation elements having membranes are ideally sufficiently permeable for the pressure difference to suffice for an automatic air circulation.

(19) Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments.

(20) It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure.

(21) The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.

LIST OF REFERENCE SIGNS

(22) 10 Illumination unit 20,21 Illumination assembly, end 22 Illumination assembly, central 30 Housing 31 Cover plate 32 Housing wall, rear wall 40 Air inlet opening 41 Air outlet opening 50 Air circulation, air flow 51 Air inlet flow 52 Air outlet flow 60 Vehicle interior 70 Outer area x,y,z Vehicle coordinate system z Height difference y Distance