Light module intended to be mounted in an optical assembly for a motor vehicle

Abstract

The invention relates to a light module intended to be mounted in an optical assembly for a motor vehicle. The light module comprises a light source (4), an optical reflector (8) reflecting the light emitted by the light source (4) and a screen (12) placed in front of the optical reflector (8). The edge (16) of the optical reflector (8) facing the screen (12) is extended by a rim (18) extending in the direction of the screen (12), and the periphery (20) of the screen (12) facing the optical reflector (8) is curved so as to extend parallel or substantially parallel to the rim (18) of the optical reflector (8), and the rim (18) of the optical reflector (8) is kept at a distance from the screen (12) so as to allow an air flow to pass between the optical reflector (8) and the screen (12).

Description

[0001] The present invention relates to a light module intended to be mounted in an optical unit for a motor vehicle.

[0002] Regulations require that every motor vehicle be equipped with light modules for lighting and signaling, to warn road users of the position and intentions of the motor vehicle.

[0003] A light module consists of a light source combined with its own optics, so as to allow the projection of a light beam that complies with regulations.

[0004] Documents CN 103 994 386 A, JP 2014 157693 A, CN 207 112 688 U describe known light modules.

[0005] To facilitate the installation of light modules on a vehicle, they are first grouped into optical blocks. These optical blocks are then fitted into designated slots in the vehicle's body. A single optical block thus allows for the quick and easy installation of multiple light modules on a vehicle simultaneously.

[0006] To achieve this, an optical unit comprises a standardized optical housing designed to fit perfectly into a housing in the body of a motor vehicle. The light modules are arranged within this optical housing. The optical housing includes an opening that is covered by a transparent lens, allowing the light modules to illuminate the vehicle's surroundings while protecting them from the elements and dust.

[0007] Over time, the arrangement and appearance of light modules within headlight assemblies have become important differentiating factors between motor vehicles. Partially transparent screens have been placed in front of the lenses of the light modules, particularly in front of the reflectors, to produce a strong visual signature.

[0008] However, the more appealing the visual signature, the more difficult it is to guarantee a crisp appearance. Even the slightest bleed around the screen can spoil the final result. This is especially true when the screen is partially opaque due to the application of a metallic layer, which creates a distinctive light pattern when the backlight module is activated. The edges of the light pattern must be sharp, particularly at its periphery. The screen's edges must therefore remain dark when illuminated by the light source.

[0009] To achieve this, it is known to seal the edges of the screen to the optical reflector of the light module in a tight or nearly tight manner, ensuring that no light emitted by the light source can create a halo around the screen. In other words, no airflow occurs between the optical reflector and the screen of the light module.

[0010] This results in a disadvantage when the light module is on, a temperature difference between the inside of the light module and the inside of the optical housing, thus promoting a condensation phenomenon on the surface of the screen of the light module and the surface of the glass sealing the optical block.

[0011] It is then necessary to coat the screen of the light module, as well as the glass of the optical block, with an anti-condensation varnish. However, the use of an anti-condensation varnish is expensive and can lead to surface defects that alter the appearance of the light beams emitted by the optical block.

[0012] The present invention aims to solve this technical problem, by proposing a light module comprising a screen backlit by a light source, preventing a condensation phenomenon on the surface of the screen during the operation of the light module.

[0013] To solve this technical problem, a light module according to the invention as defined in claim 1, intended to be mounted in an optical block for a motor vehicle, comprises a light source, an optical reflector reflecting the light emitted by the light source and a screen placed in front of the optical reflector, the screen being able to transmit at least a part of the light reflected by the optical reflector.

[0014] The invention is remarkable in that the edge of the optical reflector opposite the screen is extended by a rim extending towards the screen, and the perimeter of the screen opposite the optical reflector is curved so as to extend parallel or substantially parallel to the edge of the optical reflector, and the edge of the optical reflector is kept at a distance from the screen so as to allow the passage of an airflow between the optical reflector and the screen.

[0015] The invention also relates to the following embodiments: the length of the rim of the optical reflector, defined according to a direction parallel or substantially parallel to the direction of emission of the light beam emitted by the light module, is between 2 mm and 20 mm, preferably between 5 mm and 15 mm; the smallest distance between the rim of the optical reflector and the perimeter of the screen opposite the optical reflector is between 0.5 mm and 10 mm, preferably between 0.5 mm and 2 mm;

[0016] According to the invention, the rim of the optical reflector has a smaller thickness than the thickness of the edge of the optical reflector, so as to form a riser delimiting the edge of the rim of the optical reflector, and the height of the riser is greater than the thickness of the screen's perimeter, and the screen's perimeter is kept opposite the riser so as not to exceed the riser;

[0017] According to the invention, the riser is adjacent to an external face of the optical reflector, the external face being opposite an internal face of the optical reflector illuminated by the light source .

[0018] The invention also relates to the following embodiments The perimeter of the screen opposite the optical reflector is extended by several retaining appendages, each retaining appendage is able to attach to a lug present on the edge of the optical reflector; the perimeter of the screen opposite the optical reflector is extended by several centering appendages, each centering appendage is configured to fit into a slot present on the edge of the optical reflector.

[0019] The invention also relates to a vehicle headlight assembly, comprising an optical housing with an opening covered by a glass panel. The headlight assembly includes a light module as described above, and the optical reflector of the light module has a retaining appendage that cooperates with an internal wall of the optical housing to hold the optical reflector to the internal wall.

[0020] According to one embodiment, the perimeter of the screen opposite the optical reflector has a notch, and the optical reflector and / or the optical housing has a notch opposite the notch of the optical reflector, so as to allow or promote the passage of an airflow between the inner wall of the optical housing, the optical reflector and the screen.

[0021] According to another embodiment, the perimeter of the screen opposite the optical reflector includes a riser resting against a wall of the optical housing.

[0022] Other advantages and features will become clearer from the description that follows.

[0023] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the drawings in which: [ Fig. 1 ] represents a schematic view of a longitudinal section of an optical block comprising a light module according to the invention; [ Fig. 2 ] represents a schematic view of a partial longitudinal section of a light module illustrated on the figure 1 ; [ Fig. 3 ] represents a schematic view from below of the block illustrated on the figure 1 ; [ Fig. 4 ] represents a schematic view of a partial longitudinal section of a light module illustrated on the figure 1 showing a clipping system; [ Fig. 5 ] represents a schematic view of a partial longitudinal section of a light module illustrated on the figure 1 showing a guidance system to facilitate alignment between the screen and the optical reflector of the light module; [ Fig. 6 ] represents a schematic view of a partial longitudinal section of a light module illustrated on the figure 1 including notches to facilitate the circulation of airflow within the optical block.

[0024] In these figures, the same references are used to designate the same elements.

[0025] As a reminder, the invention proposes a light module comprising a screen backlit by a light source, making it possible to prevent a condensation phenomenon on the surface of the screen of the light module during its operation.

[0026] THE figures 1 à 6 illustrate a non-limiting embodiment of a light module 2 according to the invention, mounted in a vehicle optical unit. As illustrated by the figure 1 The light module 2 includes a light source 4 capable of emitting a light beam 6 that meets regulatory specifications. In this example, the light source 4 is capable of emitting a white, red, or amber light beam 6.

[0027] The light module 2 includes an optical reflector 8 arranged opposite the light source 4, so that an inner face 10 of the optical reflector reflects at least a part of the light beam 6 emitted by the light source 4 towards a screen 12.

[0028] According to this example, the inner face 10 of the optical reflector is concave in shape. The optical reflector is made from one of the following materials: polycarbonate, acrylonitrile butadiene styrene, poly(methyl methacrylate).

[0029] The inner face 10 of the optical reflector is preferably coated with a metallized layer to enhance its reflective properties. The optical reflector has an outer face 14 connected to the inner face 10 by means of an edge 16 facing the screen 12. In this example, the outer face 14 is substantially parallel to the inner face 10.

[0030] The edge 16 of the optical reflector, located opposite the screen 12, is extended by a rim 18. The rim extends towards the screen 12. In this example, the rim extends parallel or substantially parallel to the direction of emission of the light beam emerging from the light module 2. The length of the rim 18 of the optical reflector 8, defined along a direction parallel or substantially parallel to the direction of emission of the light beam 6 emitted by the light module, is between 2 mm and 20 mm, preferably between 5 mm and 15 mm. The thickness of the rim 18, defined along a direction normal or substantially normal to the inner face 10 of the optical reflector, is between 10 mm and 40 mm, preferably between 15 mm and 25 mm.

[0031] As mentioned above, the light module includes a screen 12, arranged opposite the inner face 10 of the optical reflector, so as to be backlit by the light beam 6 emitted by the light source 4. In this example, the screen is transparent. The screen 12 is made from one of the following materials: poly(methyl methacrylate) or polycarbonate.

[0032] The screen 12 is partially covered by a layer opaque to the light beam 6 emitted by the light source 4, so that a luminous pattern appears and is visible to an observer when the light module 2 is activated. In particular, the edge of the screen is covered by the opaque layer in such a way as to highlight the luminous pattern. The opaque layer may be present on an inner or outer face of the screen. The term "inner face" refers to a face of an object directly illuminated by the light beam 6.

[0033] As mentioned above, the invention proposes an original solution to preserve the dark outline of the screen 12, by avoiding a phenomenon of light beam leakage 6 around the screen when the light source 4 is activated, while limiting the risk of formation of a condensation layer on the surface of the screen 12.

[0034] To achieve this, the invention proposes an original arrangement between the optical reflector 8 and the screen 12. More precisely, as illustrated by the figure 2 The perimeter 20 of the screen located opposite the optical reflector 8 is curved so as to extend parallel or substantially parallel to the edge 18 of the optical reflector 8, and the edge 18 of the optical reflector is kept at a distance from the screen 12 so as to allow the passage of an airflow between the optical reflector 8 and the screen 12. In other words, this particular tile-like assembly, between the edge 18 of the optical reflector 8 and the perimeter 20 of the screen, delimits a sinuous, chicane-like passage so as to completely prevent the light beam 6 emitted by the light source 4 from reaching the outside of the light module 2, while allowing the circulation of an airflow between the outside and the inside of the light module 2.

[0035] According to the present example, the smallest distance between the rim 18 of the optical reflector 8 and the perimeter 20 of the screen opposite the optical reflector is between 0.5 mm and 10 mm, preferably between 0.5 mm and 2 mm, to promote sufficient air circulation between the inside and outside of the light module 2 in order to prevent condensation on the screen 12.

[0036] In a direction parallel or substantially parallel to the light beam transmitted by the screen 12, the perimeter 20 of the screen 12 overlaps the edge 18 of the optical reflector 8, over a distance between 5 mm and 50 mm, preferably between 5 mm and 15 mm, in order to strongly attenuate the intensity of a light beam propagating between the screen 12 and the optical reflector 8, preferably to attenuate the intensity completely.

[0037] It should be noted that the rim 18 of the optical reflector 8 is thinner than the edge 16 of the optical reflector, thus forming a riser 22 that separates the edge 16 from the rim 18 of the optical reflector. The riser 22 is perpendicular or substantially perpendicular to the inner face 10 of the optical reflector. The height of the riser is greater than the thickness of the screen's perimeter 20, so that the screen's perimeter remains aligned with the riser 22 without extending beyond it. In other words, the riser 22 is formed so that the perimeter 20 of the screen 12 is a continuation of the outer face 14 of the optical reflector 8, thereby preserving the homogeneity of the outer surface of the light module 2.

[0038] As illustrated by the figures 3 And 4The screen 12 is held to the optical reflector by means of retaining appendages 24. Each retaining appendage 24 comprises a tab 26 extending parallel to the outer face 14 of the optical reflector. Each tab includes an opening 28 designed to cooperate with a lug 30 present on the outer face 14 of the optical reflector 8, so as to ensure that the perimeter 20 of the screen is held to the edge 16 of the optical reflector 8 by a reversible clipping technique.

[0039] To facilitate the alignment of the tabs 26 with the lugs 30, the screen 12 also includes centering appendages 32 visible on the figures 3 And 5Each centering appendage 32 consists of a tab 34 extending parallel to the outer face 14 of the optical reflector. The free ends of the tabs 34 are narrow, V-shaped or U-shaped, to fit more easily into dedicated recesses 36 on the outer face 14 of the optical reflector.

[0040] In this example, the light module 2 is arranged in an optical housing 38 of an optical unit 40, intended for mounting on a motor vehicle. The optical housing 38 has an opening covered by a lens 42. The lens is transparent and protects the light module from weathering and external dust. The light module 2 is arranged so that its screen 12 is opposite the lens 42.

[0041] To ensure better retention of the light module 2 in the optical housing 38, the optical reflector 8 has, on its outer face 14, a retaining appendage 44 visible on the figure 5 cooperating with a dedicated housing 46 present on an internal face 48 of the optical housing 38.

[0042] Preferably, the perimeter 20 of the screen opposite the optical reflector 8 has one or more notches 50, and the optical reflector 8 and / or the optical housing 38 also has one or more notches 50 opposite the notch of the optical reflector, so as to allow the passage of an airflow between the inner face 48 of the optical housing 38, the optical reflector 8, and the screen 12. This embodiment is visible in the figure 6 promotes greater air circulation in the optical block 40.

[0043] Preferably, the notches 50 are present at the areas of the screen least illuminated by the light beam 6, for example at the corners of the screen 12.

[0044] Possibly, as illustrated by the figure 2 , the perimeter 20 of the screen opposite the optical reflector 8 may include a riser 52 bearing against a wall 54 of the optical housing 38, so as to ensure greater support of the screen 12 against the optical housing 38.

Claims

1. / Light module (2) intended to be mounted in an optical unit (40) for a motor vehicle, comprising a light source (4), an optical reflector (8) reflecting the light emitted by the light source (4) and a screen (12) placed in front of the optical reflector (8), the screen (12) being capable of transmitting at least part of the light reflected by the optical reflector (8), characterized in that the edge (16) of the optical reflector (8) opposite the screen (12) is extended by a rim (18) extending in the direction of the screen (12), and in that the periphery (20) of the screen (12) opposite the optical reflector (8) is curved so as to extend parallel or substantially parallel to the rim (18) of the optical reflector (8), and in that the rim (18) of the optical reflector (8) is kept at a distance from the screen (12) so as to allow the passage of an air flow between the optical reflector (8) and the screen (12), and in that the edge (18) of the optical reflector (8) has a thickness smaller than the thickness of the edge (16) of the optical reflector (8), so as to form a riser (22) delimiting the edge (16) of the edge (18) of the optical reflector (8), and in that the height of the riser (22) is greater than the thickness of the perimeter (20) of the screen (12), and in that the perimeter (20) of the screen (12) is held opposite the riser (22) so as not to exceed the riser (22), and in that the riser (22) is adjacent to an external face (14) of the optical reflector (8), the external face (14) being opposite an internal face (10) of the optical reflector (8) illuminated by the light source (4).

2. / Light module (2) according to claim 1, characterized in that the length of the edge (18) of the optical reflector (8), defined in a direction parallel or substantially parallel to the direction of emission of the light beam (6) emitted by the light module (2), is between 2 mm and 20 mm.

3. / Light module (2) according to claim 1 or 2, characterized in that the smallest distance between the edge (18) of the optical reflector (8) and the periphery (20) of the screen (12) opposite the optical reflector (8), is between 0.5 mm and 10 mm.

4. / Light module (2) according to one of claims 1 to 3, characterized in that the periphery (20) of the screen (12) opposite the optical reflector (8) is extended by several holding appendages (24), each holding appendage is capable of being fixed to a lug (30) present on the edge (16) of the optical reflector (8).

5. / Light module (2) according to one of claims 1 to 4, characterized in that the periphery (20) of the screen (12) opposite the optical reflector (8) is extended by several centering appendages (32), each centering appendage is configured to be inserted into a housing (36) present on the edge (16) of the optical reflector (8).

6. / Optical unit (40) for a motor vehicle, comprising an optical housing (38) having an opening closed by a glass (42), characterized in that it comprises a light module (2) according to one of claims 1 to 5, and in that the optical reflector (8) of the light module (2) comprises a holding appendage (44) cooperating with an internal face (48) of the optical housing (38), so as to hold the optical reflector (8) on the internal face (48).

7. / Optical unit (40) according to claim 6, characterized in that the perimeter (20) of the screen (12) facing the optical reflector (8) comprises a notch (50), and in that the optical reflector (8) and / or the optical housing (38) comprises a notch (50) facing the notch of the optical reflector (8), so as to allow the passage of an air flow between the internal wall of the optical housing (38), the optical reflector (8) and the screen (12).

8. / Optical unit (40) according to claim 6 or 7, characterized in that the perimeter (20) of the screen (12) facing the optical reflector (8) comprises a riser (52) bearing against a wall (54) of the optical housing (38).

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