EP3721136A1

EP3721136A1 - Discreet lighting device for a motor vehicle

Info

Publication number: EP3721136A1
Application number: EP18830913.2A
Authority: EP
Inventors: Alain Buisson
Original assignee: Marelli Automotive Lighting France SAS
Current assignee: Marelli Automotive Lighting France SAS
Priority date: 2017-12-05
Filing date: 2018-12-04
Publication date: 2020-10-14
Also published as: WO2019110920A1; FR3074566B1; FR3074566A1

Abstract

The invention relates to a discreet lighting device for a motor vehicle. According to the invention, the lighting device (2A, 2B, 2C, 2D) comprises a housing (4), closed at a front face (6) by a screen (10), and a light source (12) arranged in the housing (4) to illuminate the screen (10). The screen (10) comprises a translucent layer (14) configured to diffuse the light emitted by the light source (12) and a metallised layer (16) for reflecting the light originating from outside the housing (4), and the translucent layer (14) and the metallised layer (16) are respectively oriented towards the inside and the outside of the housing (4). The metallised layer helps, in particular, to conceal the inside of the housing (4) so as to give it a more discreet appearance.

Description

DISCRETE LUMINOUS DEVICE FOR MOTOR VEHICLE

TECHNICAL FIELD TO WHICH THE INVENTION REFERS

[01] The present invention relates to a light device for a motor vehicle. It relates more particularly to a lighting device and / or signaling more discreet when off, to preserve the aesthetics of the motor vehicle.

BACKGROUND

[02] The luminous devices make it possible to fulfill various lighting and signaling functions imposed by the regulations in force in the field of the automobile. These include direction indicators or flashing lights, brake lights, fog lights, position lights, parking lights, hazard lights and retro-reflectors. In practice, these light devices are integrated into the vehicle structure so as to be visible to other road users.

[03] The presence of these luminous devices significantly modifies the appearance of motor vehicles. Over time, the position and shape of lighting devices have become differentiating factors for motor vehicles. The use of light-emitting diodes has allowed a greater variety of shapes of light devices for less space. This has made it possible to make these lighting devices more discreet and more aesthetic.

[04] Nevertheless, the current lighting devices incorporate optical elements of complex shapes and colors, protected from the external environment by means of a transparent screen in order to preserve the lighting properties of the luminous device. These optical elements are thus visible by an observer, thus modifying locally and significantly the aesthetic appearance of the motor vehicle. The presence of luminous devices are all the more visible by day, whereas these are generally little or not used.

[05] The present invention aims to provide an original way to make more discreet day light devices on motor vehicles, to preserve the aesthetic appearance of said vehicles.

OBJECT OF THE INVENTION

[06] In order to overcome the aforementioned drawbacks, the present invention proposes a light device for a motor vehicle comprising a housing, closed at a front face by a screen, and a light source arranged in the housing to illuminate the screen .

[07] The invention is remarkable in that the screen has a translucent layer configured to diffuse the light emitted by the light source and a metallized layer to reflect light from outside the housing, and that the translucent layer and the metallized layer are oriented respectively inside and outside the housing.

[08] In other words, the screen placed in front of the light source comprises at least two distinct superposed layers: a translucent layer and a metallized layer at least partially covering the translucent layer. The metallized layer is oriented toward the exterior of the housing and configured to reflect ambient ambient light so that at least a portion of the interior of the housing is not visible by day by an observer. Preferably, the metallized layer completely covers the translucent layer so that the elements contained in the housing are not apparent when the light device is off. In other words, thanks to the presence of the metallized layer, the screen conceals the contents of the housing behind a surface reflecting daylight. The appearance of the light device is therefore apparently much less complex for an observer, compared to the light devices described above. The invention thus makes it possible to limit the visual impact of light devices on a motor vehicle. Therefore, the invention provides a more discreet light device day. The translucent layer advantageously makes it possible to opacify the metallized layer visible from outside the light device, while allowing to homogenize the light beam emitted by the light source present in the housing, so as to allow a more uniform illumination by the light device.

[09] Preferably, the metallized layer comprises a support layer based on polymethyl methacrylate, supporting a layer based on one or more metal elements. The support layer is configured to allow the covering of flat or curved surfaces, to allow the presence of a homogeneous or substantially homogeneous layer on a translucent screen of convex and / or concave shape. In other words, the metallized layer may be in the form of a coating film applied against the translucent layer. Preferably, the coating film is able to deform when heated, to facilitate its application against the translucent layer.

[10] According to another embodiment of the invention, the housing is opaque to the external light. This embodiment aims to promote greater darkness in the housing to allow better concealment behind the screen elements contained in the housing.

[11] According to another embodiment of the invention, the translucent layer closes the housing. This embodiment aims to promote greater darkness within the housing.

[12] According to another embodiment of the invention, the translucent layer and the metallized layer are in contact. According to an alternative embodiment, the translucent layer and the metal layer may be distant.

[13] According to another embodiment of the invention, the thickness of the translucent layer is equal to or greater than twice the thickness of the metallized layer. In other words, the translucent layer can serve as a support for the metallized layer. The thickness of the metallized layer is chosen so as to reflect the light of day while allowing the passage of a light beam emitted by the light source present in the housing. By way of nonlimiting example, the thickness of the metallized layer is equal to or less than 7 miti, preferably between 3 pm and 5 pm or between 4 pm and 5 pm.

[14] According to another embodiment of the invention, the translucent layer is formed from acrylonitrile butadiene styrene (ABS).

[15] According to another embodiment of the invention, the translucent layer has a thickness of between 200 μm and 250 μm. In this thickness range, it is advantageous to use thermoforming techniques to produce screens in three dimensions. [16] According to another embodiment of the invention, the metallized layer is colored. According to a preferred embodiment, the translucent layer is non-uniformly colored, with one or more distinct colors to form patterns visible to an observer from outside the light device. [17] According to another embodiment of the invention, the metallized layer is made from one of the following materials: chromium, stainless steel, bronze, aluminum or tungsten. Of course, this list is not limiting so that the skilled person can cover the translucent screen with a metal of another nature fulfilling the same functions. [18] According to another embodiment of the invention, the translucent layer has through passages said layer, whose dimensions are configured to form areas illuminated by the light source more intensely at the metallized layer. This embodiment aims at forming patterns on the surface of the metallized layer when the light source is turned on. Preferably, the smallest dimension of a passage is between 1 mm and 5 cm, preferably between 1 cm and 3 cm.

[19] According to another embodiment of the invention, the translucent layer is screen printed on at least one of its faces, so as to modify locally its transmittance when it is illuminated by light source.

[20] According to another embodiment of the invention, a face of the translucent layer is completely covered by the metallized layer.

[21] According to another embodiment of the invention, the light device comprises a transparent layer placed in front of the metallized layer, so that the metallized layer is present between the translucent layer and the transparent layer.

[22] According to another embodiment of the invention, the transparent layer is in contact with the metallized layer. This embodiment is particularly advantageous when it is desired that the screen forms an outer shell or a light of a traffic light.

[23] According to another embodiment of the invention, the transparent layer is colored, preferably red.

[24] According to another embodiment of the invention, a light device described above may be a lighting and / or signaling device such as a taillight.

[25] Of course, the various features, variations and embodiments mentioned above may be associated with each other in various combinations, to the extent that they are not incompatible or exclusive of each other.

[26] The invention also relates to a shock park for a motor vehicle with a metallised surface, comprising a housing in which is inserted the screen of a light device according to one of the preceding claims, and in that the metallized layer is of similar or identical color to the shock park. It should be noted that the invention is not limited to a shock park but to any element constituting a part of the bodywork of a motor vehicle, such as a tailgate, a wing, a door, etc. [27] The invention also relates to a body for a motor vehicle comprising a housing in which is present a light device described above, the screen being oriented towards the outside of the body and the metallized layer being of similar or identical color to the bodywork.

DESCRIPTION OF THE FIGURES

[28] The invention will be better understood, thanks to the following description, which relates to preferred embodiments, given by way of non-limiting examples, and explained with reference to the appended diagrammatic drawings, in which:

- Figure 1A shows a daylight and a cross section of a light device according to the invention;

- Figure 1 B shows at night and lit a cross section of a light device according to the invention;

- Figure 2 shows a day and extinguished a front view of a shock-chromed park incorporating a light device shown in Figure 1;

- Figure 3A shows a daylight and a cross section of a variant of a light device according to the invention;

FIG. 3B shows at night and on a cross section of the light device illustrated in FIG. 3A;

- Figure 4A shows a daylight and a cross section of a variant of a light device according to the invention;

- Figure 4B shows a night and lit a cross section of the light device shown in Figure 4A;

- Figure 5A shows a daylight and a cross section of a variant of a light device according to the invention;

- Figure 5B shows at night and lit a cross section of the light device shown in Figure 5A.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT

[29] As a reminder, the invention aims to provide an original way to make more discreet day light devices present on motor vehicles, to preserve the aesthetic appearance of said vehicles. [30] As illustrated in Figure 1A, a light device 2A according to the invention comprises a housing 4 open at a front face 6. The housing is opaque in nature so as not to let the outside light. According to the present example, the housing is made from a plastic material of acrylonitrile butadiene styrene (ABS), polycarbonate (PC) type or a mixture of both. The inner surface 8 of the housing is dark or light in color.

[31] A screen 10 is pressed against the front face 6 by known means, so as to close the housing 4 to protect the external environment a light source 12 in said housing. The light source 12 is arranged to illuminate at least a part of the screen 10 by light beams shown in Figure 1 B. According to the present example, the light source 12 comprises a light emitting diode.

[32] The screen 10 has a translucent layer 14 facing the inside of the housing 4. In other words, the translucent layer is in contact with the front face 6 of the housing. By the term "translucent" is meant a layer configured to pass the light beam emitted by the light source 12 as shown in Figure 1 B, without it being possible to clearly distinguish the contours of said beam. According to the present example, the translucent layer 14 is made from acrylonitrile butadiene styrene (ABS), polycarbonate (PC) or polymethyl methacrylate (PMMA). Preferably, the translucent layer is grained, sandblasted or grooved to increase its ability to diffuse the light beam emitted by the light source 12. Its thickness is between 1 mm and 3 mm, preferably between 200 μm and 350 μm. .

[33] The screen 10 also comprises a metallized layer 16 superimposed on the translucent layer 14. The metallized layer is oriented towards the outside of the housing 4. By the term "metallized" is meant a layer composed of a metal element like chrome, stainless steel, bronze, aluminum or tungsten. Its thickness is between 7 μm, preferably between 3 μm and 5 μm or between 4 μm and 5 μm. [34] Advantageously, the metallized layer 16 makes it possible to reflect the light coming from the outside of the light device 2A as illustrated by FIG. 1A, so that the elements present in the housing 4 are not visible when the source of light 12 is off. Thus, by day, the appearance of the light device is similar to a more or less homogeneous surface of a metallic color as shown in FIG. 2. Conversely, when the light source 12 is on, the light beam emitted by said source passes through the translucent layer and the metallized layer so that the light device can be used as direction indicators or flashing lights, stop lights, fog lights, parking lights, parking lights or hazard lights.

[35] The light device 2A described above is intended to be integrated with a bodywork element of a motor vehicle, such as a shock park 18 illustrated in FIG. 2. According to the present example, the shock park comprises a housing 20 in which is inserted the light device 2A so that its screen 10 is flush with the surface of the shock park. The surface of the shock park is chromed and the metallized layer 16 of the screen 10 is composed mainly of chromium, so that the appearance of the screen 10 is similar or identical to that of the shock park 18. Thus, Advantageously, the light device 2A is discreetly integrated in the shock-park without locally changing its aesthetic appearance. Of course, when the light source is activated, its light beam passes through the screen 10 in order to be visible by an observer. According to the present example, the light source 12 emits a red or white beam to form respectively a stop light or a recoil light.

[36] Figures 3A and 3B show an alternative embodiment of the light device 2A described above. According to this variant, the light device 2B comprises a transparent layer 22 placed in front of the screen 10 so that the metallized layer 16 is present between the translucent layer 14 and the transparent layer 22. It should be noted that the identical elements are designated by the same references in the figures. The transparent layer 22 may for example form the outer shell or a lantern or a parking light for a motor vehicle. By the term "transparent" is meant a layer configured to pass the light beam emitted by the light source 12 as shown in Figure 3B, so that one can clearly distinguish the contours of said beam. According to the present example, the thickness of the transparent layer 22 is between 2 mm and 3 mm.

[37] Figures 4A and 4B show another alternative embodiment of the light device 2A described above. According to this variant, the light device 2C comprises a transparent layer 22 placed against the screen 10 so that the metallized layer 16 is present between the translucent layer 14 and the transparent layer. The translucent layer 14 is then configured to protect the metallized layer from the weather conditions so that the screen 10 can be used as an outer shell or sight of a lantern, or a position light for a motor vehicle. According to the present example, the thickness of the transparent layer 22 is between 2 mm and 3 mm.

[38] Figures 5A and 5B show another alternative embodiment of the light device 2A described above. According to this variant, the 2D light device comprises a transparent layer 22 placed in front of the screen 10 so that the metallized layer 16 is present between the translucent layer 14 and the transparent layer 22. The transparent layer 22 may for example form the outer shell or sight, a lantern or a position light for a motor vehicle. The transparent layer 22 also serves as a support for the metallized layer 16, so as to no longer be in contact with the translucent layer 14 as in the examples described above. According to the present example, the thickness of the transparent layer 22 is between 2 mm and 3 mm.

[39] Of course, the invention is not limited to the embodiments described above, so that the skilled person can make various modifications without departing from the scope of the invention.

Claims

1. Light device (2A, 2B, 2C, 2D) for a motor vehicle comprising a housing (4), closed at a front face (6) by a screen (10), and a light source (12) arranged in the housing (4) for illuminating the screen (10), characterized in that the screen (10) has a translucent layer (14) configured to diffuse light emitted from the light source (12) and a metallized layer (16) for reflecting light from outside the housing (4), the metallized layer (16) comprises a polymethylmethacrylate-based support layer supporting a layer based on one or more metal elements, and the translucent layer (14) and the metallized layer (16) are respectively oriented towards the inside and the outside of the housing (4).

2. Light device (2A, 2B, 2C, 2D) according to the preceding claim, characterized in that the housing (4) is opaque to the external light.

3. Light device (2A, 2B, 2C, 2D) according to one of the preceding claims, characterized in that the translucent layer (14) closes the housing (4).

4. Light device (2A, 2B, 2C) according to one of the preceding claims, characterized in that the translucent layer (14) and the metallized layer (16) are in contact.

5. luminous device (2A, 2B, 2C, 2D) according to one of the preceding claims, characterized in that the thickness of the translucent layer (14) is equal to or greater than twice the thickness of the metallized layer ( 16).

6. Light device (2A, 2B, 2C, 2D) according to one of the preceding claims, characterized in that the translucent layer (14) is formed from acrylonitrile butadiene styrene.

Light device (2A, 2B, 2C, 2D) according to one of the claims previous, characterized in that the translucent layer (14) has a thickness of between 200 μm and 250 μm.

8. Light device (2A, 2B, 2C, 2D) according to one of the preceding claims, characterized in that the metallized layer (16) is colored.

9. Light device (2A, 2B, 2C, 2D) according to one of the preceding claims, characterized in that the metallized layer (16) is made from one of the following elements: chrome, stainless steel, bronze, aluminum or tungsten.

10. Luminous device (2A, 2B, 2C, 2D) according to one of the preceding claims, characterized in that the translucent layer (14) comprises through passages said layer, whose dimensions are configured to form areas illuminated by the light source (12) more intensely at the metallized layer (16).

11. Luminous device (2A, 2B, 2C) according to one of the preceding claims, characterized in that a face of the translucent layer is completely covered by the metallized layer.

12. Luminous device (2B, 2C) according to one of the preceding claims, characterized in that it comprises a transparent layer (22) placed in front of the metallized layer (16), so that the metallized layer is present between the layer translucent (14) and the transparent layer (22).

13. Light device (2C, 2D) according to the preceding claim, characterized in that the transparent layer (22) is in contact with the metallized layer (16).

14. Luminous device (2B, 2C) according to claim 12 or 13, characterized in that the transparent layer is colored, preferably red.

15. Bodywork for a motor vehicle comprising a housing (20) in which is present a light device (2A, 2B, 2C) according to one of the preceding claims, and in that the screen (10) is oriented towards the outside of the body and the metallized layer (16) is colored similar or identical to the bodywork.