vehicle light

Abstract

A vehicle lamp (3), comprising: a lamp housing (4) with an opening (5), a lens (6) which is attached to the opening (5) and is configured to close the opening (5) and to delimit a space (7) in the lamp housing (4) in which a light source (8) is arranged, wherein the lamp housing (4) is coated with a diffusion barrier (18) which has a greater resistance to the diffusion of moisture than the lamp housing (4) itself and which is configured to prevent moisture from diffusing from outside the vehicle lamp (3) into the space (7), characterized in that a protective agent (19) is applied to a surface of the diffusion barrier (18), which is configured to prevent oxidation of the surface of the diffusion barrier (18).

Description

[0001] The invention relates to a vehicle lamp and a vehicle with a lamp. A vehicle lamp of this type is known from US 2010 / 0 232 167 A1.

[0002] Vehicles such as cars, trucks, and buses can have various lights (colloquially: lamps), such as headlights, brake lights, indicator lights, and parking lights. Such lights typically have a lamp (light source) in a sealed housing, preventing water, dirt, and the like from reaching the lamp, reflective surfaces, and translucent areas of the light. However, thermal fluctuations during use of the lamp, thermal fluctuations due to environmental changes, or thermal fluctuations due to vehicle operation can lead to moisture condensation inside the housing, reducing the light output of the lamp. It is therefore desirable to prevent moisture from penetrating a lamp housing.

[0003] German patent application DE 10 2013 213 542 A1 describes how the amount of water bound in the interior of the housing of a vehicle lamp can be kept to a minimum. The approach is based on a situation in which moisture has already penetrated the vehicle lamp. To this end, the inner surface of the lamp housing and / or another component of the vehicle lamp is at least partially hydrophobized to reduce its wettability. This prevents droplets from running down the surface and the formation of a surface film on the inner surface of the lamp housing.

[0004] The invention aims to overcome or at least mitigate the above problems. In particular, one goal of the invention is to reduce the occurrence of condensation in a vehicle lamp and to ensure long-term functional reliability of such a vehicle lamp.

[0005] According to the invention, this object is achieved with a vehicle lamp having the features specified in claim 1.

[0006] According to an optional embodiment of the invention, the diffusion barrier is applied to the lamp housing using at least one of the following techniques: vacuum metallization, adhesive bonding, mechanical bonding, or insert molding. This allows the coating to be applied to the lamp housing in a relatively reliable and simple manner.

[0007] According to another optional embodiment of the invention, the diffusion barrier is made of metal, preferably aluminum. A metal barrier has been proven effective in eliminating or at least reducing diffusion.

[0008] According to a further optional embodiment of the invention, an outer surface of the luminaire is coated with the diffusion barrier. This prevents moisture absorption on and in the lamp housing and thus also prevents moisture from penetrating the lamp housing.

[0009] According to a further optional embodiment of the invention, an inner surface of the lamp housing is coated with the diffusion barrier. This also effectively prevents moisture from penetrating the lamp housing.

[0010] According to a further optional embodiment of the invention, an outer surface and an inner surface of the lamp housing are coated with diffusion barriers. This effectively prevents the lamp housing from absorbing moisture and therefore also from penetrating the lamp housing.

[0011] According to a further optional embodiment of the invention, the lens is coated with a diffusion barrier. This also prevents moisture from penetrating the lamp housing via the lens.

[0012] The invention also teaches a vehicle with one of the lights described above.

[0013] The above general description and the following detailed description are exemplary and serve to explain the claimed invention. Other advantages and benefits of the invention will become more apparent from the claims and the detailed description with reference to the figures. BRIEF DESCRIPTION OF THE CHARACTERS

[0014] The invention will now be described in more detail with reference to the figures: Fig. 1 is a side view of a vehicle with a lamp. Fig. 2 is a section through a luminaire according to some embodiments. Fig. 3 is a cross-sectional view of a lamp according to some embodiments. Fig. 4 is a cross-sectional view of a lamp according to some embodiments. DESCRIPTION OF DETAILS

[0015] The invention will now be described with reference to the figures, which show some exemplary embodiments. Known functions or designs are not described in detail in order to illustrate the invention more clearly.

[0016] Fig. Figure 1 shows a side view of a vehicle 1 with a cabin 2 and an externally mounted light 3. The vehicle 1 may be a truck. The light 3 may be a (head)light.

[0017] Fig. 2 shows a cross-section through the lamp 3. The lamp 3 has a lamp housing 4 with an opening 5, a lens 6 which is attached to the opening 5 to close the opening 5 and which delimits a space 7 in the housing 4, wherein a lamp (light source) 8 is arranged in the space 7. The lamp 8 can have at least one device selected from a group containing an LED (light-emitting diode), an OLED (organic light-emitting diode), a laser diode, a halogen lamp, a xenon lamp or an incandescent lamp. In some embodiments, the lamp can be a solid-state light source, such as an LED or an OLED. The lamp 8 can be connected to a socket 12. The socket 12 (e.g. base) has connections 13 for the electrical connection of the lamp 8 to an electrical system (not shown) of the vehicle. A reflector 14 is arranged in the lamp housing 4.The optics of the luminaire 3 are at least partially integrated into the reflector 14 to shape the light beam 15 emitted by the light source 8 and exiting via the lens 6, which may be transparent. The luminaire housing 4 may be bowl- or cup-shaped. In some embodiments, the luminaire housing 4 is made of plastic. In some embodiments, the luminaire 3 may be a sealed luminaire in which the lens 6 and the luminaire housing 4 are hermetically bonded and sealed during manufacture. The luminaire 8 may also be sealed within the luminaire 3. In such sealed luminaires, the space 7 may be completely protected against contamination unless the lens 6 or the luminaire housing 4 is damaged.

[0018] The luminaire housing 4 can absorb moisture to varying degrees. Moisture can also diffuse into the space 7, where condensation can occur, e.g., due to changes in temperature. The rate at which moisture migrates or diffuses through a material depends on two factors: the difference between the water vapor pressure in the air outside the luminaire 3 and inside the space 7, and the resistance the material offers to the migration of moisture by diffusion. Since luminaire housings are often made of relatively porous material, such as plastic, there is a risk of diffusion.

[0019] The luminaire housing 4 is therefore coated with a diffusion barrier 18, which offers greater resistance to the diffusion of moisture than the luminaire housing 4 itself, in order to prevent moisture from outside the luminaire 3 from diffusing into the space 7. The moisture can be water vapor. In some embodiments, the diffusion barrier 18 is attached to the luminaire housing 4 using at least one of the following techniques: vacuum metallization, adhesive bonding, mechanical bonding, or insert molding. In some embodiments, the diffusion barrier 18 is made of metal. In some embodiments, the diffusion barrier 18 is made of aluminum. In some embodiments, the diffusion barrier 18 is made of a polyethylene film. In some embodiments, the diffusion barrier can be a lacquer layer.In some embodiments, the diffusion barrier 18 has a thickness of 4 to 8 microns (micrometers).

[0020] A protective agent 19 is applied to a surface of the diffusion barrier 18 to prevent oxidation of the surface. In some embodiments, the protective agent 19 may be a polymer. In some embodiments, the protective agent 19 may be a paint layer. In some embodiments, the protective agent 19 may be a lacquer layer. In some embodiments, the lacquer may be transparent.

[0021] Fig. 2 shows an embodiment in which an inner surface 20 of the luminaire housing 4 is coated with the diffusion barrier 18 in order to prevent moisture from diffusing from outside the luminaire 3 into the space 7.

[0022] Fig. 3 shows an embodiment in which an outer surface 21 of the luminaire housing 4 is coated with the diffusion barrier 18 in order to prevent moisture from diffusing from outside the luminaire 3 into the space 7.

[0023] Fig. 4 shows an embodiment in which both the inner surface 20 and the outer surface 21 of the luminaire housing 4 are coated with a diffusion barrier 18 to prevent moisture from diffusing from outside the luminaire 3 into the space 7.

[0024] As the Fig. 2, Fig. 3 and Fig. 4, the bowl- or cup-shaped luminaire housing 4 may have a rear wall 19 and side walls 11. Both the rear wall 10 and the side walls 11 may be coated with a diffusion barrier 18. In some embodiments, the lens 6 may be coated with a diffusion barrier 18. The coating may be, for example, a lacquer or a transparent film, for example, a thin film of tin oxide. Fig. 2 shows an example in which an inner surface of the lens 6 is coated with the diffusion barrier 18. Fig. 3 shows an embodiment in which an outer surface 24 of the lens 6 is coated with the diffusion barrier 18 and Fig. 4 shows an embodiment in which both the inner surface 23 and the outer surface 24 of the lens 6 are coated with a diffusion barrier 18.

[0025] In some embodiments, the lamp housing 4 may contain a desiccant to prevent fogging on the interior walls of the lens 6, the lamp housing 4, or the reflector 14. The desiccant absorbs water vapor that may enter the housing, particularly when the lamp is off. When the lamp is on, heat generated by the lamp 8 dries the air and the desiccant, thereby regenerating the desiccant. The desiccant may be packaged silica (silicon dioxide, silicon oxide) in gel form or a similar material.

[0026] The vehicle 1 has been described here as a truck, but it can also be, for example, a bus or a car. The vehicle 1 can be any commercial vehicle or a construction vehicle or the like. The vehicle 1 can also be a semi-trailer or a trailer, etc. The light 3 has been described as a headlight, but it can also be another vehicle light, for example a brake light, a turn signal or a parking light. According to one embodiment, the vehicle light can also be a work light that is to be attached to a vehicle. In a further embodiment, the vehicle light can also be an auxiliary light that is to be attached to a vehicle.

[0027] While the invention has been described in detail above using preferred embodiments, various modifications and variations will be apparent to those skilled in the art without departing from the scope of the invention. The appended claims cover such modifications and variations within the scope of the invention.

Claims

[1] Vehicle lamp (3), comprising: a lamp housing (4) with an opening (5), a lens (6) which is attached to the opening (5) and is designed to close the opening (5) and to delimit a space (7) in the lamp housing (4) in which a light source (8) is arranged, wherein the lamp housing (4) is coated with a diffusion barrier (18) which has a greater resistance to the diffusion of moisture than the lamp housing (4) itself and which is designed to prevent moisture from diffusing from outside the vehicle lamp (3) into the space (7), characterized by that a protective agent (19) is applied to a surface of the diffusion barrier (18), which is designed to prevent oxidation of the surface of the diffusion barrier (18). [2] Vehicle lamp (3) according to claim 1, characterized bythat the diffusion barrier (18) is attached to the luminaire housing (4) by means of at least one of the following techniques: vacuum metallization, adhesive bonding, mechanical bonding and insert molding. [3] Vehicle lamp (3) according to one of claims 1 or 2, characterized by that the diffusion barrier (18) is made of metal. [4] Vehicle lamp (3) according to one of claims 1 to 3, characterized by that the diffusion barrier (18) is made of aluminum. [5] Vehicle lamp (3) according to one of claims 1 to 4, characterized by that an outer surface (21) of the luminaire housing (4) is coated with the diffusion barrier (18). [6] Vehicle lamp (3) according to one of claims 1 to 4, characterized by that an inner surface (20) of the luminaire housing (4) is coated with the diffusion barrier (18). [7] Vehicle lamp (3) according to one of claims 1 to 4, characterized bythat an outer surface (21) and an inner surface (20) of the luminaire housing (4) are coated with the diffusion barrier (18). [8] Vehicle lamp (3) according to claim 1, characterized by that the lamp housing (4) is made of a plastic. [9] Vehicle lamp (3) according to claim 1, characterized by that the illuminant (8) is a solid-state illuminant. [10] Vehicle lamp (3) according to claim 1, characterized by that the lens (6) is coated with a further diffusion barrier (18). [11] Vehicle with a vehicle lamp (3) according to one of claims 1 to 10.

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