Title: Vehicle lighting device

[0001] This invention is related to the field of the internal design of vehicle lighting devices, to avoid excessive temperature increase therein.

[0002] Current light devices are mainly based on solid-state light sources, such as Light Emitting Diodes (LED). These light sources are usually arranged in a matrix structure and the lighting device comprises a plurality of lens to project the light pattern produced by the light sources.

[0003] These lenses are arranged in a metallic barrel which provides structural support and dimensional stability. However, the position of the lens near the light source makes that light absorption increases the temperature of the lenses, thus reaching a temperature which is very close or even above the limit operation temperature of the lens. This overheating can deteriorate the optical properties of the lenses, so a solution for this problem is sought.

[0004] In a first inventive aspect, the invention provides a solution for the aforementioned technical problem by means of a vehicle lighting device comprising:

- a housing;

- a light source installed in the housing, configured to emit a light pattern;

- a support barrel, with a barrel surface and a first barrel contact area protruding from the barrel surface;

- a holder element comprising a first holder contact area, the first holder contact area being arranged to connect the first barrel contact area to the housing; and

- a plurality of lenses supported in the support barrel, the lenses being configured to project the light pattern; wherein the support barrel further comprises at least a second barrel contact area which is in thermal contact with a second holder contact area of the holder element. [0005] In a preferred embodiment, the light source comprises a plurality of solid- state light sources.

[0006] The term "solid state" refers to light emitted by solid-state electroluminescence, which uses semiconductors to convert electricity into light. Compared to incandescent lighting, solid state lighting creates visible light with reduced heat generation and less energy dissipation. The typically small mass of a solid-state electronic lighting device provides for greater resistance to shock and vibration compared to brittle glass tubes/bulbs and long, thin filament wires. They also eliminate filament evaporation, potentially increasing the lifespan of the illumination device. Some examples of these types of lighting comprise semiconductor light-emitting diodes (LEDs), organic light-emitting diodes (OLED), or polymer light-emitting diodes (PLED) as sources of illumination rather than electrical filaments, plasma or gas.

[0007] The support barrel is a part which is commonly used in some solid-state light source devices. This barrel is used as a support for a plurality of lenses which project the light pattern emitted by the light sources. This barrel tends to overheat due to light absorption and this invention provides a way of avoiding this overheating.

[0008] In some particular embodiments, the surface of the second barrel contact area is greater than the surface of the first barrel contact area.

[0009] This provides a greater heat exchange between the barrel and the holder element, so that the heat dissipation is more effective.

[0010] In some particular embodiments, at least a portion of the second barrel contact area is in direct contact with the second holder contact area.

[0011 ] This direct contact ensures a good thermal contact, and saves space in the interior of the lighting device.

[0012] In some particular embodiments, at least a portion of the second barrel contact area is in thermal contact with the second holder contact area by the interposition of an additional conductive element. [0013] The interposition of an additional conductive element is useful when the geometry of the lighting device does not allow a direct contact, or when the additional conductive element has a higher thermal conductivity than the holder element itself.

[0014] In some particular embodiments, the additional conductive element is a conductive glue. In other particular embodiments, the additional conductive element is a metallic ring.

[0015] These solutions are interesting because there is no need of modifying the existing holder element, and just by the interposition of any of these two additional conductive elements, the heat dissipation is increased.

[0016] In some particular embodiments, at least a portion of the second barrel contact area forms between 2 ^Q and 5 ^Q with at least a portion of the second holder contact area.

[0017] This is useful to allow regulation movements between the barrel and the holder.

[0018] Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealised or overly formal sense unless expressly so defined herein.

[0019] In this text, the term “comprises” and its derivations (such as “comprising”, etc.) should not be understood in an excluding sense, that is, these terms should not be interpreted as excluding the possibility that what is described and defined may include further elements, steps, etc.

[0020] To complete the description and in order to provide for a better understanding of the invention, a set of drawings is provided. Said drawings form an integral part of the description and illustrate an embodiment of the invention, which should not be interpreted as restricting the scope of the invention, but just as an example of how the invention can be carried out. The drawings comprise the following figures: [0021 ] [Fig. 1 ] shows a section view of a particular embodiment of a vehicle lighting device according to the invention.

[0022] [Fig. 2] shows a section view of an alternative particular embodiment of a vehicle lighting device according to the invention.

[0023] [Fig. 3] shows a perspective view of some of the elements of the particular embodiment of Figure 2.

[0024] [Fig. 4] shows a thermal analysis of the embodiment of Figure 2.

[0025] In these figures, the following reference numbers have been used:

[0026] 1 Flousing

[0027] 2 LEDs

[0028] 3 Barrel

[0029] 30 Barrel surface

[0030] 31 First barrel contact area

[0031 ] 32 Second barrel contact area

[0032] 4 Holder element

[0033] 41 First holder contact area

[0034] 42 Second holder contact area

[0035] 5 Lens

[0036] 6 Thermal ring

[0037] 10 Lighting device

[0038] 100 Automotive vehicle

[0039] The example embodiments are described in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternate forms and should not be construed as limited to the examples set forth herein. [0040] Accordingly, while embodiment can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed. On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included.

[0041] Figure 1 shows a section view of a particular embodiment of a vehicle lighting device 1 according to the invention. In this figure, the vehicle lighting device 10 comprises

- a housing 1 ;

- a plurality of LEDs 2 installed in the housing 1 ;

- a support barrel 3;

- a holder element 4; and

- a plurality of lenses 5 supported in the support barrel 3.

[0042] The plurality of LEDs 2 are installed in the housing and are configured to emit a light pattern, due to their particular arrangement. This light pattern is received and projected by the plurality of lenses 5, which are arranged to as to provide a final pattern to perform a particular lighting functionality.

[0043] The support barrel 3 is intended to provide a support for the plurality of lenses 5. This support barrel 3 comprises a barrel surface 30 and a first barrel contact area 31 which protrudes from the barrel surface 30. This first barrel contact area 31 is used to attach the support barrel to the first holder contact area 41 of the holder element 4, which is in turn attached to the housing 1. Hence, the first barrel contact area 31 is the attachment point of the support barrel 3 to the housing 1 , via the holder element 4.

[0044] The support barrel 3 further comprises a second barrel contact area 32, with a surface greater than the surface of the first barrel contact area 31. This second barrel contact area 32 is in thermal contact with a second holder contact area 42 of the holder element 4, thus creating a thermal path for heat dissipation between the barrel 3 and the holder 4. [0045] Heat coming from the light absorption performed by the barrel 3 is conducted along the conductive surface of the barrel and then dissipated by the holder 4, due to the thermal contact between the second barrel contact area 32 and the second holder contact area 42, so that the lenses 5 do not reach a dangerous temperature.

[0046] In this figure, the second barrel contact area 32 is in contact with the second holder contact area 42, by the mere interposition of a conductive glue layer. This contact saves space and provides the barrel 3 with a good heat dissipation path. The shape and size of the contact zone may be designed as a function of the heat dissipation needs of the lighting device.

[0047] At least a portion of the second barrel contact area 32 forms between 2 ^Q and 5 ^Q with at least a portion of the second holder contact area 42.

[0048] Figure 2 shows a section view of an alternative embodiment of a lighting device according to the invention.

[0049] This figure also illustrates an embodiment with a housing 1 , a plurality of LEDs 2 installed in the housing 1 , a support barrel 3, a holder element 4 and a plurality of lenses 5, with the same operation functionalities as in the embodiment of Figure 1.

[0050] In this case, there is a difference between the thermal conduction between the support barrel 3 and the holder element 4. The second barrel contact area 32 and the second holder contact area 42 are not in direct contact, but thermally connected by an additional metallic ring 6. This metallic ring 6 is interposed between the two contact areas 32, 42 and ensures a good heat dissipation for the support barrel 3.

[0051 ] Figure 3 shows a perspective view of some of the elements of the particular embodiment of Figure 2.

[0052] In this figure, the barrel 3 and the holder 4 are shown. The contact surfaces are hidden by the holder 4 itself, since the contact surfaces are present in the inner side of the holder 4. This figure is only presented to provide a complete view of some of the elements involved in the present invention. [0053] Figure 4 shows a thermal analysis of the embodiment of Figure 1.

[0054] In this figure, it may be seen how the heat is transferred from the support barrel 3 to the holder element 4, so that the final temperature in the lenses 5 is lower than the risk threshold temperature.