Ambient lighting system for motor vehicles

Abstract

The invention relates to an ambient lighting device (1) comprising two lighting modules, each comprising a respective tubular light guide (110, 210) supplied, at one of its ends called the inlet, by a corresponding light source, each said guide comprising a connecting section extending from its inlet end and intended to be concealed behind a trim panel (3), as well as a working section intended to be arranged opposite a respective portion of an elongated opening (2) provided in said panel, said guides crossing by overlapping at the junctions between their respective connecting and working sections, so that the working sections extend in line with each other; said device also comprising a diffusing screen (400) arranged in front of said guides and having at least a first area of ​​extra thickness (420) located opposite the crossing area between said guides.Figure to be published with the abbreviation: Fig. 3.

Description

Title of the invention: Ambient lighting device for motor vehicles. Technical field

[0001] The present invention relates to ambient lighting devices for motor vehicles. More particularly, it relates to those intended to be integrated into interior trim elements of such a vehicle, such as the dashboard, doors, or headliner. Prior art

[0002] The passenger compartment of a motor vehicle includes a set of interior lighting means which, for some, perform useful lighting functions and, for others, perform so-called ambient lighting functions, giving the driver and other passengers of the vehicle an impression of comfort and calm.

[0003] Ambient lighting improves the perception of comfort for the driver and passengers, and contributes to the aesthetics and attractiveness of the vehicle at the time of the purchase decision.

[0004] For this purpose, the vehicle is equipped with ambient lighting devices diffusing a low intensity light, coloured or not, often adjustable, and installed on various interior trim elements of the vehicle such as the dashboard, the doors, or even the roof.

[0005] Such an ambient lighting device typically comprises a lighting module including a tubular light guide designed to be positioned opposite an elongated opening in a trim panel of the interior trim element. This guide is supplied, at one of its ends, referred to as the input end, by a light source typically consisting of one or more light-emitting diodes. A diffuser screen is also typically arranged in front of this light guide.

[0006] The ambient lighting is switched on for example as soon as the exterior lighting of the vehicle is switched on, or according to the measurement taken by a light sensor, or when one of the vehicle's openings is opened (side door or trunk lid).

[0007] The arrangement of a single light source at one end of the light guide is problematic, particularly when the latter has a significant length, due to the loss of luminous flux along this guide.

[0008] In order to overcome this drawback when it is desired to obtain a light strip of considerable length (typically greater than 500 millimeters), ambient lighting devices are known comprising two lighting modules each comprising a respective tubular light guide supplied, at one of its so-called input ends, by a corresponding light source.

[0009] Each said light guide includes a connecting section extending from its entry end and intended to be concealed behind a trim panel of an interior trim element of said vehicle, as well as a working section intended to be arranged opposite a respective portion of an elongated opening provided in said trim panel.

[0010] The two light guides cross by overlapping at the junctions between their respective connecting and useful sections, so that the useful sections of said guides extend in line with each other along said opening in order to generate a continuous light band visible from inside the passenger compartment of said vehicle.

[0011] Unfortunately, the overlap of the two light guides in this crossing area locally causes an overintensity of light generating the appearance of a "hot spot" degrading the perceived quality level of the vehicle.

[0012] We also know from patent application FR 3 051 539 Al, an ambient lighting device comprising a single light guide including a useful section intended to be arranged opposite an elongated opening made in a trim panel of an interior trim element, as well as two connecting sections made from a single piece of molding with the useful section and converging at one of their ends at the same point of this useful section.

[0013] Each of these connecting sections is powered, at its second end, called the input end, by a corresponding light source. These two connecting sections thus allow the light rays emitted by the two light sources to be guided, by successive internal reflections, towards the interior of the useful section.

[0014] Due to the section transition occurring at the junction between the connecting sections and the useful section, it unfortunately turns out that some light rays from these connecting sections do not propagate inside the useful section and leak outside the light guide, generating visual defects. Description of the invention

[0015] The present invention aims to provide homogeneous lighting without "hot spots" over the entire length of the light strip.

[0016] To this end, it proposes an ambient lighting device for motor vehicles, comprising two lighting modules, each including a guide to respective tubular light powered, at one of its ends called the input, by a corresponding light source, each said light guide comprising a connecting section extending from its entry end and intended to be concealed behind a trim panel of an interior trim element of said vehicle, as well as a working section intended to be arranged opposite a respective portion of an elongated opening provided in said trim panel, said light guides intersect by overlapping at the junctions between their respective connecting and useful sections, so that the useful sections of said guides extend in line with each other along said opening in order to generate a continuous light strip visible from inside the passenger compartment of said vehicle, said device also comprising a diffuser screen arranged in front of said light guides; characterized in that said diffusing screen has at least a first area of ​​extra thickness located opposite the crossing area between said light guides.

[0017] The addition of this thicker area thus allows the diffusing screen to locally absorb a larger part of the light rays it receives, so as to reduce the "hot spot" phenomenon occurring at the level of this crossing area due to the overintensity of light caused by the superposition of the two light guides in this area.

[0018] The invention thus makes it possible to obtain a relatively homogeneous ambient light band over the entire length of the opening, which contributes to significantly improving the perceived quality level of the vehicle.

[0019] According to preferred characteristics of said ambient lighting device according to the invention: - said first zone of extra thickness extends opposite a proximal portion of the useful section of each of the two light guides; - said proximal portion of each useful section of said light guide extends over a length between 0.5 and 2 centimetres; - said first zone of extra thickness also extends in relation to the connecting sections of said light guides; - said diffusing screen also has several secondary areas of extra thickness, each located opposite surface irregularities present on said light guides; - the difference in thickness between the said thickened area(s) and the rest of the said diffusing screen is between 1 and 3 millimeters; - said diffusing screen advantageously comes from one-piece molding from a translucent thermoplastic polymer such as polycarbonate (PC) or polymethyl methacrylate (PMMA); and / or - said diffuser screen is made of Tarflon® V1700R (W3032E).

[0020] The invention also relates, in a second aspect, to an interior trim element of a motor vehicle comprising such an ambient lighting device.

[0021] The invention finally relates, in a third aspect, to a motor vehicle comprising at least one such interior trim element. Brief description of the drawings

[0022] The description of the invention will now be continued by a detailed description of an example embodiment, given below by way of illustration but not limitation, with reference to the accompanying drawings, on which: - [Fig.1] is a perspective view of an ambient lighting device for a motor vehicle according to the invention; - [Fig.2] represents a perspective view of the ambient lighting device of [Fig.1], without the diffuser screen; - [Fig.3] is a section view of the ambient lighting device of [Fig.1], taken at the crossing of the two light guides; - [Fig. 4] represents an enlargement of detail IV of [Fig. 2], showing the area where the two light guides intersect; and - [Fig.5] is a rear view enlargement of the portion of the diffuser screen covering the crossing area of ​​the light guides. Description of the implementation methods

[0023] Figures 1 to 3 illustrate an ambient lighting device 1 according to the invention, intended to be integrated into an interior trim element of a motor vehicle (such as, for example, the dashboard, a side door or the roof lining) to form a continuous luminous strip along an elongated opening 2 provided in a trim panel 3 of this trim element (this trim panel 3 and this opening 2 being shown only on [Fig.3]).

[0024] The lighting device 1 comprises two lighting modules 100, 200 each comprising a tubular light guide with a respective circular cross-section 110, 210 supplied, at one of its ends called the entrance, by a corresponding light source not visible in the figures and arranged so that its emission axis is substantially perpendicular to the face forming the entrance end of this light guide 110, 210.

[0025] The light rays entering through the inlet end of each light guide 110, 210 thus propagate along the latter by successive reflections on its outer envelope in the direction of its opposite outlet end.

[0026] Each light guide 110, 210 is preferably made in one piece by molding from a transparent thermoplastic material, possibly dyed in mass such as polycarbonate (PC) or polymethyl methacrylate (PMMA).

[0027] The light source of each lighting module 10, 20 is advantageously made up of one or more light-emitting diodes (LEDs) or laser, mounted on an electronic control board with printed circuit boards (or PCB for "Printed Circuit Board") not visible in the figures and housed in a respective plastic housing 120, 220 also intended to be concealed behind the trim panel 3 of the interior trim element of the vehicle.

[0028] Managing the operation of the light sources, the electronic control boards are, for example, capable of automatically varying the light intensity emitted by these sources according to certain parameters measured by sensors, such as ambient light. Each connected to the vehicle's electrical circuit via a power supply harness (not shown), these electronic control boards are also advantageously coupled to ensure synchronous operation of the two lighting modules 110 and 210.

[0029] The housings 120, 220 are each advantageously made by assembling two parts, each molded from a thermoplastic polymer such as polyamide (PA), optionally reinforced with mineral fibers to enhance their mechanical strength. As illustrated in [Fig. 4], each housing 120, 220 comprises a cylindrical shaft 121, 221 receiving the inlet end of a respective light guide 110, 210 so as to optically couple it to a corresponding light source.

[0030] Still referring to [Fig. 4], the light guides 110, 210 each comprise: - a connecting section 111,211 extending from its entry end and intended to be concealed behind the trim panel 3 (shown in [Fig.3]); and - a useful section 112, 212 intended to be arranged opposite a respective portion of the elongated opening 2 provided in this trim panel 3.

[0031] As illustrated by figures 2 to 4, the two light guides 110, 210 cross by overlapping at the junctions J between their respective connecting sections 111,211 and useful 112, 212, so that the useful sections 112, 212 of these two guides 110, 210 extend in line with each other along this opening 2 in order to generate a continuous light band visible from inside the vehicle's passenger compartment.

[0032] Using two light guides 110, 210 associated with two light sources thus makes it possible to generate a luminous flux of more homogeneous intensity along the aperture 2 (the loss of luminous flux between the two ends of each light guide 110, 210 being less compared to a lighting device comprising a single light guide extending over the entire length of this aperture 2).

[0033] The ambient lighting device 1 also includes a support 300 having two receiving grooves 310, 320 (see [Fig.4]) into which the two light guides 110, 210 are inserted fixedly by snapping and joining at the crossing area between these guides 110, 210 as illustrated by [Fig.3].

[0034] Advantageously made from a single piece molding of an opaque thermoplastic material such as a polypropylene advantageously reinforced with natural and / or synthetic fibers (for example, a talc-filled polypropylene such as PPTD40), the support 300 also includes two housings 330, 340 in which the two housings 120, 220 are fixedly housed by snap-fit ​​(see [Fig.4]).

[0035] Each lighting module 100, 200 may also advantageously include a collimator (not visible in the figures) housed in the cylindrical shaft 121, 221 of the housing 120, 220 between the light source and the light guide 110, 210, so as to direct and concentrate the light beam from this light source towards the light guide 110, 210.

[0036] The lighting device 1 further comprises a diffuser screen 400 arranged in front of the light guides 110, 210, which it completely covers. The term "in front" should be understood here as meaning that the diffuser screen 400 is interposed between these light guides 110, 210 and the eyes of a passenger seated in the vehicle's passenger compartment, so that the light rays reaching them have previously passed through this diffuser screen 400.

[0037] The 400 diffuser screen is advantageously produced by molding in one piece from a translucent thermoplastic polymer such as polycarbonate (PC) or polymethyl methacrylate (PMMA). Even more preferably, it is made of a polycarbonate marketed under the reference Tarflon® V1700R (W3032E) and produced by Idemitsu Kosan Co., Ltd.

[0038] Having a shape and profile complementary to those of the support 300, the diffuser screen 400 is fixedly attached by snapping against the front face of this support 300. To do this, this diffuser screen 400 includes several elastically deformable snapping tabs 410 provided along its peripheral edge (one of them being visible on [Fig.5]) and cooperating by snapping with corresponding teeth 350 provided along the peripheral edge of the support 300 (one of them being visible on [Fig.4]).

[0039] According to the invention and as illustrated by [Fig.5], this diffusing screen 400 has at least a first area of ​​extra thickness 420 located opposite the crossing area between the two light guides 110, 210. The addition of this area of ​​extra thickness 420 allows the diffusing screen 400 to locally absorb a greater part of the light rays it receives, so as to reduce the "hot spot" phenomenon occurring at the crossing area due to the overintensity of light caused by the superposition of the two light guides 110, 210 in this area.

[0040] The invention thus makes it possible to obtain a relatively homogeneous ambient light band over the entire length of the opening 2, which contributes to significantly improving the perceived quality level of the vehicle.

[0041] In order to further limit this "hot spot" phenomenon and still with reference to figures 4 and 5, the first area of ​​extra thickness 420 is preferentially extended in relation to a proximal portion 112A, 212A of the useful section 112, 212 of each of the two light guides 110, 210.

[0042] For an optimal optical result, this proximal portion 112A, 212A of each useful section 112, 212 extends over a length advantageously between 0.5 and 2 centimeters.

[0043] Furthermore, and in order to avoid the appearance of parasitic light areas due to the reflection of light rays emitted by the connecting sections 111,211 of the light guides 110, 210 on surrounding walls, the first area of ​​extra thickness 420 is also advantageously extended in relation to these connecting sections 111, 211.

[0044] Finally, and in order to avoid the appearance of parasitic light areas due to the reflection of light rays emitted from surface irregularities present on the light guides 110, 210 (for example at the level of the injection areas of the plastic material during molding), the diffusing screen 400 also preferentially presents several secondary overthickness areas 430 located opposite these surface irregularities (one of these secondary overthickness areas 430 being visible on [Fig.5]).

[0045] Advantageously between 1 and 3 millimeters, the difference in thickness between the area(s) of extra thickness 420, 430 and the rest of the diffuser screen 400 can be easily adjusted by removing or adding material in the injection mold used to manufacture this diffuser screen 400 so as to obtain the most homogeneous light band possible.

Claims

Demands

1. Ambient lighting device (1) for a motor vehicle, comprising two lighting modules (100, 200), each comprising a respective tubular light guide (110, 210) supplied, at one of its ends, referred to as the inlet end, by a corresponding light source, each said light guide (110, 210) comprising a connecting section (111, 211) extending from its inlet end and intended to be concealed behind a trim panel (3) of an interior trim element of said vehicle, and a working section (112, 212) intended to be arranged opposite a respective portion of an elongated opening (2) formed in said trim panel (3), said light guides (110, 210) intersecting by overlapping at the junctions (J) between their connecting (111, 211) and working sections (112, 212) respective, so that the useful sections (112, 212) of the said guides (110,210) extend in line with each other along said opening (2) in order to generate a continuous light strip visible from inside the passenger compartment of said vehicle, said device (1) also comprising a diffuser screen (400) arranged in front of said light guides (110, 210); characterized in that said diffuser screen (400) has at least a first area of ​​increased thickness (420) located opposite the area of ​​intersection between said light guides (110, 210).

2. Ambient lighting device (1) according to claim 1, characterized in that said first area of ​​extra thickness (420) extends in relation to a proximal portion (112A, 212A) of the useful section (112, 212) of each of the two light guides (110, 210).

3. Ambient lighting device (1) according to claim 2, characterized in that said proximal portion (112A, 212A) of each useful section (112, 212) of said light guide (110, 210) extends over a length of between 0.5 and 2 centimeters.

4. Ambient lighting device (1) according to any one of claims 1 to 3, characterized in that said first area of ​​extra thickness (420) also extends in relation to the connecting sections (111, 211) of said light guides (110, 210).

5. Ambient lighting device (1) according to any one of claims 1 to 4, characterized in that said diffusing screen (400) further has several secondary overthickness zones (430) each located opposite surface irregularities present on said light guides (110, 210).

6. Ambient lighting device (1) according to any one of claims 1 to 5, characterized in that the difference in thickness between said thickening zone(s) (420, 430) and the rest of said diffusing screen (400) is between 1 and 3 millimeters.

7. Ambient lighting device (1) according to any one of claims 1 to 6, characterized in that said diffusing screen (400) advantageously comes from one-piece molding from a translucent thermoplastic polymer such as polycarbonate (PC) or polymethyl methacrylate (PMMA).

8. Ambient lighting device (1) according to claim 7, characterized in that said diffuser screen (400) is made of Tarflon® V1700R (W3032E).

9. Interior trim element of a motor vehicle comprising an ambient lighting device (1) according to any one of claims 1 to 8.

10. Motor vehicle comprising at least one interior trim element according to claim 9.

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