Passive LED vehicle light ventilation device

Abstract

Ventilation device (1) for a LED vehicle light module (100), wherein the device (1) comprises an air channel (10) having an input opening (11), an output opening (12), and a bleed opening (13), wherein the air channel (10) comprises a nozzle section (14) which comprises a tapered cross-section such that the cross-section is bigger (14.1) coming from the input opening (11) and getting smaller (14.2) in direction to the output opening (12), wherein the bleed opening (13) is positioned in the nozzle section (14) and configured to direct bleed air through the bleed opening (13) out of the device (1) due to a pressure gradient between air in the nozzle section (14) flowing through the air channel (10) and air outside the device (1).

Description

[0001] The invention relates to the field of ventilation systems for LED vehicle lights. LED front lights are facing major problem with humidity condensation especially during cold and humid part of the year. In comparison to classical bulbs, LED light sources are not radiating the heat from the light source towards covering glass, but to the heatsinks, which are placed on the opposite side, close to the engine compartment. Due to small thermal waste production, the covering glass is coldest surface in the lamp and causes water humidity condensates on it. The condensed water needs to be removed in certain time after a car is turned on and running.

[0002] Related art for led vehicle light ventilation devices relates to open ventilation systems and closed ventilation systems.

[0003] Open systems have one or more openings in the back of the light module housing, which are covered by a. Plastic tubes filled with a filtration material (foam, etc.) b. Plastic labyrinths filled with filtration materials.

[0004] Open systems are used mostly in simplified versions of headlights due to bad dust protection. Open systems are passive, there is no forced air circulation by a fan or something similar.

[0005] Closed systems can be divided into passive systems and active systems.

[0006] Passive systems use different types of membranes as a cover for openings which function is to ventilate air humidity, stabilize pressure difference between inner and outer environment. There is no forced air circulation in the inner environment. An example of a passive system is described in JP 2007 201110 A.

[0007] Active systems, an example of which is described in JP 2002 124123 A, using a fan are used in two different conditions. If a heatsink itself is not able to sufficiently cool down the LED chips, or if forced air circulation is needed.

[0008] Closed systems are used in majority of production worldwide, however a problem is the low air circulation if no additional electric devices are used.

[0009] The inventors found it disadvantageous that passive systems, especially passive closed systems, are not very effective while active systems are relatively complex and expensive.

[0010] The problem underlying the invention was to improve this disadvantage. The problem is solved by the invention, in particular according to the independent claims. Further relevant embodiments of the invention are described in further devices according to the invention.

[0011] In particular, this problem is solved by a passive ventilation device for a LED vehicle light module, wherein the device comprises an air channel, preferably defined by walls made of air-impermeable material, having an input opening, an output opening, and a bleed opening, wherein the air channel comprises a nozzle section which comprises a tapered cross-section such that the cross-section is bigger coming from the input opening and getting smaller in direction to the output opening, wherein the bleed opening is positioned in the nozzle section, preferably laterally, sideward of the air channel and configured to direct bleed air through the bleed opening out of the device due to a pressure gradient between air in the nozzle section flowing through the air channel and air outside the device.

[0012] Hereby, a passive ventilation device is achieved with a forced pressure gradient that can be achieved by the mere air movements due do the motion of the car when driving. Hence the effectiveness of an existing passive system is improved.

[0013] In a further device according to the invention, the bleed opening is covered by a filter mesh or an air- and steam permeable membrane.

[0014] Hereby, the device is configured as a closed device, with protection against dust. As the air is "pressed" through the mesh or membrane, the disadvantage of less air circulation by closing the opening is not so significant anymore. For example, the membrane could be a Tetratex ®< (by Donaldson) or a TEMISH ®< (by Nitto Denko) membrane.

[0015] In a further device according to the invention, the channel is made of a base and a cover, which are separated by one or more spacers which are at least partially tapered in order to form the nozzle section.

[0016] Hereby, the manufacture of the device is simple.

[0017] In a further device according to the invention, the base and / or the cover are made of a plastic foil.

[0018] Hereby, the manufacture of the device is simple and cost efficient.

[0019] In a further device according to the invention, the one or more spacers are made of a foam.

[0020] Hereby, the manufacture of the device is simple and cost efficient.

[0021] In a further device according to the invention, the base, the cover and / or the one or more spacers are joined together by an adhesive.

[0022] Hereby, the manufacture of the device is simple and cost efficient.

[0023] In a further device according to the invention, the base outside surface comprises an adhesive, preferably a self-adhesive layer, such that the device is configured to be adhered to the LED vehicle light module.

[0024] Hereby, the mounting of the device to the LED vehicle light module is fast and uncomplicated.

[0025] In a further device according to the invention, the base features the bleed opening. Hereby, the manufacture of the device is simple.

[0026] According to the invention, this problem is solved by a LED vehicle light module, wherein the module comprises the passive ventilation device described above.

[0027] In the module according to the invention, the module comprises a housing enclosing a LED vehicle light unit, wherein the housing comprises a ventilation opening, wherein the bleed opening is connected to the ventilation opening such that air from the air channel can enter the housing via the bleed opening and the ventilation opening. Preferably, the housing comprises an air outlet opening, preferably covered by a filter mesh or an air- and steam permeable membrane, preferably located in a side of the housing opposite to the side featuring the ventilation opening.

[0028] The present invention will now be described - by way of example - with reference to the accompanying drawings, whereby Fig. 1a-cshow a first embodiment of a device according to the invention, Fig. 2shows a module according to the invention with a device according the second embodiment.

[0029] Now follows a more detailed description of Fig. 1a-c. Fig. 1a shows a cross-sectional top view, Fig. 1b a first cross-section and Fig. 1c a second, shifted cross-section. The device 1 comprises an air channel 10, here defined by walls made of air-impermeable material, having an input opening 11, an output opening 12, and a bleed opening 13, wherein the air channel 10 comprises a nozzle section 14 which comprises a tapered cross-section such that the cross-section is bigger 14.1 coming from the input opening 11 and getting smaller 14.2 in direction to the output opening 12, wherein the bleed opening 13 is positioned in the nozzle section 14, here laterally, sideward of the air channel 10 and configured to direct bleed air through the bleed opening 13 out of the device 1 due to a pressure gradient between air in the nozzle section 14 flowing through the air channel 10 and air outside the device 1.

[0030] Furthermore, the channel is made of a base 16 and a cover 17, which are separated by two spacers 18 which are partially tapered in order to form the nozzle section 14. The base 16 and the cover 17 are made of a plastic foil. The spacers 18 are made of a foam. The base 16, the cover 17 and the two spacers 18 are joined together by an adhesive. The base 16 outside surface comprises an adhesive, here a self-adhesive layer 16.1, such that the device 1 is configured to be adhered to the LED vehicle light module, wherein the base 16 features the bleed opening 13.

[0031] The bleed opening 13 is covered by an air- and steam permeable membrane 15 (Fig. 1b).

[0032] Now follows a more detailed description of Fig. 2, which is a cross-section as Fig. 1c. The module 100 comprises a device 1 according to the foregoing embodiment, wherein the module 100 comprises a housing 101 enclosing a LED vehicle light unit 103, wherein the housing 101 comprises a ventilation opening 102, wherein the bleed opening 13 is connected to the ventilation opening 102 such that air from the air channel 10 can enter the housing 101 via the bleed opening 13 and the ventilation opening 102. The housing 101 comprises an air outlet opening 104, covered by an air- and steam permeable membrane 105, located in a side of the housing 101 opposite to the side featuring the ventilation opening 102.Reference signs

[0033] 1device14nozzle section10air channel14.1bigger cross section11input opening14.2smaller cross section12output opening15air- and steam permeable mem-13bleed openingbrane16base102ventilation opening16.1self-adhesive layer103LED vehicle light unit17cover104air outlet opening18spacer105air- and steam permeable mem-brane100LED vehicle light module101housing

Claims

1. A vehicle light module (100), comprising a passive ventilation device (1) for a LED vehicle light module (100), wherein the device (1) comprises an air channel (10) having an input opening (11), an output opening (12), and a bleed opening (13), wherein the air channel (10) comprises a nozzle section (14) which comprises a tapered cross-section such that the cross-section is bigger (14.1) coming from the input opening (11) and getting smaller (14.2) in direction to the output opening (12), and in that the bleed opening (13) is positioned in the nozzle section (14) and configured to direct bleed air through the bleed opening (13) out of the device (1) due to a pressure gradient between air in the nozzle section (14) flowing through the air channel (10) and air outside the device (1), such that the passive ventilation device (1) ventilates during motion, without forced air circulation, through the pressure gradient, and wherein the module (100) comprises a housing (101) enclosing a LED vehicle light unit (103), wherein the housing (101) comprises a ventilation opening (102), wherein the bleed opening (13) is connected to the ventilation opening (102) such that air from the air channel (10) can enter the housing (101) via the bleed opening (13) and the ventilation opening (102).

2. A module (100) according to claim 1, wherein the bleed opening (13) is covered by a filter mesh or an air- and steam permeable membrane (15).

3. A module (100) according to one of claims 1 or 2, wherein the channel is made of a base (16) and a cover (17), which are separated by one or more spacers (18) which are at least partially tapered in order to form the nozzle section (14).

4. A module (100) according to claim 3, wherein the base (16) and / or the cover (17) are made of a plastic foil.

5. A module (100) according to one of claims 3 or 4, the one or more spacers (18) are made of a foam.

6. A module (100) according to one of claims 3 to 5, wherein the base (16), the cover (17) and / or the one or more spacers (18) are joined together by an adhesive.

7. A module (100) according to one of claims 3 to 6, wherein the base (16) outside surface comprises an adhesive, such that the device (1) is configured to be adhered to the LED vehicle light module (100).

8. A module (100) according to one of claims 3 to 7, wherein the base (16) features the bleed opening (13).

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