FR3084727A1 - LIGHT DEVICE FOR A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a light device (1) for a vehicle comprising a housing (10), a support (12) comprising a light source (13) for emitting light rays, an optical system (14) for forming a light beam from of said light rays, and comprising: - a primary optical element (140) arranged partly facing said light source (13); - a secondary optical element (141) arranged facing said primary optical element (140), connected with it via a connecting bridge (142) and comprising an input face (141a) with Fresnel steps and an output face (141b); Characterized in that said connecting bridge (142) comprises an optical pattern (142a) with an entry face perpendicular to a part of the light rays passing through said primary optical element so that they propagate without refraction or deviation through said connecting bridge to said exit face.

Description

LIGHT DEVICE FOR A MOTOR VEHICLE

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a light device for a motor vehicle.

It finds a particular but non-limiting application in raised brake lights for motor vehicles.

TECHNOLOGICAL BACKGROUND OF THE INVENTION

A light device for a motor vehicle comprises, in a manner known to a person skilled in the art:

- a housing ;

- a support comprising at least one light source configured to emit light rays;

- an optical system configured to form a light beam along an optical emission axis from said light rays, and comprising:

- a primary optical element disposed partly opposite said at least one light source;

- a secondary optical element disposed opposite said primary optical element, connected with said a primary optical element via at least one connecting bridge and comprising an entry face with Fresnel steps and an exit face.

The light device is configured to be mounted on the rear window of a motor vehicle.

A disadvantage of this state of the prior art is that due to the presence of said at least one connecting bridge, the light rays of said at least one light source are deflected which creates areas of shadow, referenced S in the figure 1 (in which the light is represented in black and the shaded areas in white), which can be observed by a person looking at the rear window of the motor vehicle. The connecting bridge is thus the site of light losses as well as inhomogeneities in the light beam formed by the light rays.

In this context, the present invention aims to provide a light device for a motor vehicle which makes it possible to solve the mentioned drawback.

GENERAL DESCRIPTION OF THE INVENTION

To this end, the invention provides a light device for a motor vehicle, said light device comprising:

- a housing ;

- a support comprising at least one light source configured to emit light rays;

- an optical system configured to form a light beam along an optical emission axis from said light rays, and comprising:

- a primary optical element disposed partly opposite said at least one light source;

- a secondary optical element disposed opposite said primary optical element, connected with said a primary optical element via at least one connecting bridge and comprising an entry face with Fresnel steps and an exit face;

Characterized in that said at least one connecting bridge comprises at least one optical pattern with an entry face substantially perpendicular to a part of the light rays passing through said primary optical element.

Thus, thanks to the optical pattern, the light rays which have passed through the primary optical element will propagate through said at least one connecting bridge to the exit face of the secondary optical element with a minimum of refraction so that 'there is very little loss of light and no shadows at the level of the connecting bridge. The light is thus diffused homogeneously.

According to non-limiting embodiments, said light device may also include one or more additional characteristics taken alone or according to all technically possible combinations, among the following:

According to a nonlimiting embodiment, said at least one optical pattern projects from said at least one connecting bridge.

According to a nonlimiting embodiment, said at least one optical pattern forms a fin.

According to a nonlimiting embodiment, said at least one optical pattern is of the same thickness as said at least one connecting bridge.

According to a nonlimiting embodiment, said at least one connecting bridge is full.

According to a nonlimiting embodiment, said exit face of said secondary optical element comprises prisms at said at least connecting bridge so as to straighten along the said optical emission axis the light rays coming from said secondary optical element.

According to a nonlimiting embodiment, the prisms are oriented so as to refract the light rays coming from said at least one connecting bridge along an axis of movement of the motor vehicle.

According to a nonlimiting embodiment, said light device comprises a plurality of light sources and a plurality of link bridges, a link bridge being surrounded by two light sources.

According to a nonlimiting embodiment, each connecting bridge comprises two optical patterns including:

- a first optical pattern with an entry face perpendicular to a part of the light rays emitted by one of the two light sources surrounding said connecting bridge; and

- a second optical pattern with an entry face perpendicular to part of the light rays emitted by the other of the two light sources.

According to a nonlimiting embodiment, the prisms are divided into two sets, one of which is configured to redirect the light rays coming from the first optical pattern and the other is configured to redirect the light rays coming from the second optical pattern.

According to a nonlimiting embodiment, the optical system is made of synthetic polymer material.

According to a nonlimiting embodiment, said light device is a raised brake light.

BRIEF DESCRIPTION OF THE FIGURES

The invention and its various applications will be better understood on reading the description which follows and on examining the figures which accompany it:

- Figure 1 shows a front view of a light distribution of the light beam generated by a light device for a motor vehicle of the state of the prior art, through an exit glass;

- Figure 2 shows a rear view of a motor vehicle equipped with a light device, according to a non-limiting embodiment of the invention;

- Figure 3a illustrates an assembled view of the light device of Figure 2, according to a non-limiting embodiment;

- Figure 3b illustrates an exploded view of the light device of Figure 3a, said light device comprising a housing, an output lens, at least one light source, and an optical system, according to a non-limiting embodiment;

- Figure 4 illustrates a view of the optical system of the light device of Figure 3b, said optical system comprising a primary optical element and a secondary optical element connected by at least one connection point, according to a non-limiting embodiment;

- Figure 5a is a zoomed view of two light sources and part of the optical system of the light device of Figures 3a to 4, according to a non-limiting embodiment;

- Figure 5b is a zoomed view of two light sources and another part of the optical system of the light device of Figures 3a to 4, according to a non-limiting embodiment;

- Figure 6a shows a perspective view of the two light sources and of the part of the optical system of Figure 5a, according to a non-limiting embodiment;

- Figure 6b shows a perspective view from below of the view of Figure 6a, according to a non-limiting embodiment;

- Figure 7 shows a diagram of the light rays emitted by said at least one light source of the light device and passing through said optical system of said light device of Figure 5a, according to a non-limiting embodiment.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Identical elements, by structure or by function, appear in the different figures keep, unless otherwise specified, the same references.

In the following description, the concepts of verticality and horizontality are expressed when the light device is oriented in a mounting position on the vehicle.

The light device 1 for a motor vehicle according to the invention is described with reference to Figures 2 to 7.

By motor vehicle is meant any type of motor vehicle.

In a nonlimiting embodiment, the light device 1 is a signaling light.

FIG. 2 is a view of the rear of a motor vehicle 2. In a conventional and known manner, the motor vehicle 2 comprises a rear window 3, the latter being able to be fixed to the bodywork or to be on a rear opening such as a tailgate.

In a nonlimiting embodiment, the light device 1 is placed at the top of the rear window 3. In a nonlimiting embodiment, it is a stop light, commonly called "third stop light", or stop light. raised stop light, with reference to the two conventional stop lights arranged lower left and right. The "third brake light" or raised brake light is also designated CHMSL, acronym for the English expression "Center High-Mounted Stop Light".

Such a raised brake light can also be installed at the bottom of the rear window, on the rear shelf or mounted in the bodywork, above the rear window or at the top of the trunk.

In a nonlimiting embodiment, the light device 1 is configured to be placed behind the rear window 3. In this case, it comprises a housing whose opening is closed by the rear window.

In another nonlimiting embodiment, the light device 1 is configured to be integrated into the bodywork. In this case, it includes a housing closed by an exit glass. This nonlimiting embodiment is taken as a nonlimiting example in the following description.

In a nonlimiting embodiment, the light device 1 extends in a main direction Y (illustrated in FIGS. 2 and 3a) which corresponds to the horizontal when it is in the mounting position on the motor vehicle 2. The light device 1 illuminates in a longitudinal direction to the motor vehicle 2 oriented towards the rear and along an optical emission axis X (illustrated in FIG. 4) close to the horizontal, so that an observer being in the optical emission axis X and near this optical emission axis X can see the light beam emitted by the light device 1.

As illustrated in FIGS. 3a and 3b, the light device 1 comprises:

- a housing 10;

- an exit glass 11;

- a support 12 comprising at least one light source 13;

- an optical system 14 comprising:

- a primary optical element 140;

a secondary optical element 141 connected with said primary optical element 140 via at least one connecting bridge 142.

The elements of the light device 1 are described in detail below.

• Box 10

As illustrated in FIGS. 3a, 3b, the housing 10 is configured to receive the support 12 with said at least one light source 13, and the optical system 14.

In a nonlimiting embodiment, the light device 1 is held in the motor vehicle 2 by means of its housing. The latter is fixed to the body via holes (not shown) made in the body.

• Exit glass 11

The exit glass 11 is configured to close the housing 10 in a dust and moisture tight manner.

It is secured to said housing 10. In a nonlimiting embodiment, said outlet glass 11 is bonded to said housing 10.

The outlet glass 11 is configured to be pressed against the rear window 3. In a nonlimiting embodiment, it is held on the body of the motor vehicle 2 by means of an adhesive film 110 illustrated in FIG. 3a. This keeps the entire light device 1 in the motor vehicle 2.

The exit glass 11 is composed of an outward-facing face through which the light beam from the light device 1 exits.

In a nonlimiting embodiment, the outlet glass 11 is transparent or translucent. It can be tinted red. It has no opaque wall.

o Support 12 and light source 13

The support 12 is illustrated in FIGS. 3b and 4.

It is placed in the housing 10.

The support 12 comprises at least one light source 13 configured to emit light rays R.

It comprises an electrical connector 120 (illustrated in FIG. 4) which makes it possible to connect it electrically to an electrical network of the motor vehicle 2.

In a nonlimiting embodiment, the support 12 is a printed circuit support, also designated PCBA, acronym of the English expression "Printed Circuit Board Assembly".

In a nonlimiting embodiment, said light source 13 is a semiconductor light source. In a nonlimiting alternative embodiment, said semiconductor light source 13 is part of a light emitting diode. By light-emitting diode is meant any type of light-emitting diode, whether in non-limiting examples of LEDs (“Light Emitting Diode”), OLEDs (“organic LEDs”), AMOLEDs (Active-Matrix-Organic LEDs), or FOLED (Flexible OLED).

Said light source 13 is configured to generate a light ray R in a direction parallel to the optical emission axis 12 of the light device 1.

In a nonlimiting embodiment, the light device 1 comprises a plurality of light sources 13. In the nonlimiting example illustrated in FIG. 3b, it comprises 16 light sources 13. This nonlimiting embodiment is taken as an example not limiting in the following description.

The light sources 13 are arranged side by side and distributed in the main direction Y of the light device 1.

The light sources 13 are configured to generate light rays R which will cooperate with the optical system 14 described below. All the light rays R of the light sources 13 form the light beam F of the light device 1. For simplicity, only the light rays R of some light sources 13 have been shown in FIG. 3b.

o Optical system 14

The optical system 14 is illustrated in FIGS. 3b to 7.

It is composed :

- a primary optical element 140 disposed partly opposite said at least one light source 13;

- a secondary optical element 141 disposed opposite said primary optical element 140, connected with said a primary optical element 140 via at least one connecting bridge 142.

The optical system 14 is configured to form a light beam F along the optical emission axis X from the light rays R of the light sources 13.

It is thus configured to distribute the light rays R coming from the light sources 13 so that the light beam F which leaves the exit glass 11 is as homogeneous as possible.

The optical system 14 is secured to the support 12 and kept away from said support 12. In a non-limiting embodiment, it is secured to the support 12 with at least one clip 145 (illustrated in FIGS. 4 and 5b). In a non-limiting variant, it comprises a plurality of fixing clips 145.

In the nonlimiting example illustrated in FIG. 4, it includes 4 fixing clips, two of which are distributed on one side of the optical system and two others on the opposite side, so as to have better fixing of the support 12.

In a nonlimiting embodiment, the optical system 14 is a single piece.

In a nonlimiting embodiment, the optical system 14 is made of synthetic polymer material.

In a nonlimiting embodiment, the optical system 14 is produced by injection molding of synthetic polymer material.

In a nonlimiting variant, the material is polycarbonate (PC) or polymethyl methacrylate (PMMA).

o Primary optical element 140

The primary optical element 140 is illustrated in FIGS. 3b to 7.

It is partly arranged opposite the light sources 13 of the support 12. It is formed from a transparent or translucent material, similar to a lens. As illustrated in FIG. 5a, it comprises a windscreen 143 which cooperates with a light source 13 to collimate the light rays R generated in the direction of the secondary optical element 141 and in the direction of the connecting bridges 142 distributed on both sides and d other of the light source 13.

The windshield 143 is arranged opposite a light source 13.

The windshield 143 is curved. In a nonlimiting embodiment, the windshield 143 is curved over a sector of between 90 ° and 180 ° so as to collect a major part of the light rays R emitted by the light source 13.

The windshield 143 includes an inlet face 143a and an outlet face 143b. In a nonlimiting embodiment, the inlet face 143a and the outlet face 143b are smooth. In another nonlimiting embodiment not illustrated, the input face 143a comprises Fresnel steps. The two nonlimiting embodiments allow the light rays R coming from the light sources 13 to be collimated vertically substantially towards the secondary optical element 141, namely perpendicular to the axis Y, and horizontally said light rays R towards the secondary optical element 141, namely along a plane parallel to the Y axis.

In a nonlimiting embodiment, the primary optical element 140 comprises a plurality of windshields 143. In the nonlimiting example illustrated in FIG. 3b, it comprises 16 windshields 143 each cooperating respectively with the 16 light sources 13.

o Secondary optical element 141

The secondary optical element 141 is illustrated in FIGS. 3b to 7.

The secondary optical element 141 is arranged opposite the primary optical element 140 so as to receive the light rays R collimated by the primary optical element 140.

It is disposed between the primary optical element 140 and the exit lens 11. Like the primary optical element 140, it is made of a transparent or translucent material, similar to a lens.

It is substantially planar and extends in the main direction Y of the light device 1.

The secondary optical element 141 comprises:

- an entrance face 141 a

- an outlet face 141b.

The input face 141a is oriented towards the light sources 13. As illustrated in FIG. 5a, it includes Fresnel steps 141c. The latter are configured to vertically collimate the light rays R coming from the light sources 13 and having passed through the lens 143 so that on the exit face 141b the light rays R are oriented parallel to the optical emission axis X.

The Fresnel steps extend substantially vertically relative to the plane of the secondary optical element 141. In other words, they are perpendicular to the main direction Y.

The exit face 141b faces the exit glass 11. Thus, the light beam F formed by the light rays R leaves the exit glass 11 to illuminate at the rear of the rear window 3.

o Link bridge 142

The connecting bridge 142 is illustrated in FIGS. 3b to 7.

The connecting bridge 142 is configured to join the two parts of the optical system 14, namely the primary optical element 140 and the secondary optical element 141.

In a nonlimiting embodiment, the optical system 14 comprises a plurality of connecting bridges 142. In the nonlimiting example illustrated in FIG. 4, it comprises 7 connecting bridges 142.

In a nonlimiting embodiment illustrated in FIGS. 5a, 6a, 6b, 7, said at least one connecting bridge 142 is full. It does not include any opening, as in the case of Figure 5b, which allows it to be more robust and cool evenly. The connecting bridge 142 serves as an injection point for injecting the synthetic polymer material.

It will be noted that the optical system 14 includes other connecting bridges 144 illustrated in FIG. 4 having an opening 148 illustrated in FIG. 5b. These other connecting bridges 144 do not need to have optical patterns 142a because they make it possible to reflect the light rays R coming from the light sources 13 in the direction of the output face 141b which extends said connecting bridges 144 so that 'there are no gray areas at this location.

As illustrated in FIGS. 5a and 7, the connecting bridge 142 comprises at least one optical pattern 142a. As illustrated in FIG. 5a, the optical pattern 142a comprises an entry face 142b substantially perpendicular to a part R1 of the light rays R passing through said primary optical element 140, in particular passing through the windshield 143, so that they propagate with a minimum of refraction through said at least one connecting bridge 142 to said outlet face 141 b.

In a nonlimiting embodiment, the entry face 142b is perpendicular to the light rays R11 joining the light source 13 at the corner of the connecting bridge 142 with the upper face of the Fresnel steps 141c. For the sake of simplification, a single light beam R11 has been illustrated. These R11 light rays are not deflected by refraction. The other light rays of part R1 are very little deflected by refraction so that there is very little loss of light on the output face 141 c.

In a nonlimiting embodiment, the optical pattern 142a projects from said at least one connecting bridge 142. This allows, while retaining the mass and therefore the resistance of said connecting bridge 142, to add to it a function of capturing a part R1 of the light rays R to direct them without refraction to an exit face 141 b.

In a nonlimiting embodiment, the added shape projecting from the optical pattern 142a has a fin shape with three sides. One of these sides is attached to the connecting bridge 142. Another side is the entry face 142b such that a part R1 of the light rays R arrives thereon substantially perpendicularly. This allows the part R1 of the light rays R not to be deflected by refraction when they enter the material of the connecting bridge 142. The last side is configured to be parallel to the part R1 of the light rays R. This allows that the light rays R do not strike this face and therefore do not modify their trajectory in the connecting bridge 142.

The optical pattern 142a is made of the same material as the connecting bridge 142 so that the light rays R1 that they pass through are not generally deflected by refraction. Thus, only a small fraction of the light rays R1 will be deflected.

Thus, the part R1 of the light rays R coming from the light source 13 and having passed through the primary optical element 140 propagates substantially in a straight line with a minimum of refraction through said connecting bridge 142 to the exit face 141b of the secondary optical element 141.

In a nonlimiting embodiment illustrated in FIGS. 6a, 6b, said at least one optical pattern 142a is of the same thickness e as said at least one connecting bridge 142. This makes it possible to recover all the light rays R propagating in the connecting bridge 142 and preventing their deflection by refraction so that there are no longer any shadow zones observed at the level of the exit glass 11, due to the absence of light rays R at the level of the bridge of connection 142 on the exit face 141b of the secondary optical element 141. The light rays R exit well through the exit face 141 b which extends the connection bridge 142.

In a nonlimiting embodiment illustrated in FIG. 4, when the light device 1 comprises a plurality of light sources 13, a connecting bridge 142 is surrounded by two light sources 13. In the case of a plurality of connecting bridges 142, each connecting bridge 142 is surrounded by two light sources 13.

In a nonlimiting embodiment, said at least one connecting bridge 142 comprises two optical patterns 142a of which:

a first optical pattern 142a with an entry face 142b perpendicular to a part R1 of the light rays R emitted by one of the two light sources 12 surrounding said connecting bridge 142; and

a second optical pattern 142a with an input face 142b perpendicular to a part R1 of the light rays R emitted by the other of the two light sources 13.

Thus, on the outlet face 141b which extends a connecting bridge 142, there are no longer any shaded areas due to the refraction of the light rays R coming from the two light sources 13 distributed on each side of the connecting bridge 142 .

In a nonlimiting embodiment illustrated in FIGS. 5a, 6a, 6b, 7, the outlet face 141b comprises prisms 143 at the level of the connecting bridge 142 so as to straighten the rays along the optical emission axis X light R1 coming from the secondary optical element 141. As can be seen in FIG. 7, the light rays R1 which have crossed the connecting bridge 142 arrive on the exit face 141b and are rectified by the prisms 143 and oriented in parallel to the optical emission axis X.

This makes it possible to be able to orient towards the exit the part R1 of the light rays R which had entered the connecting bridge 142 but which did not have the orientation of the optical emission axis X and thus avoid an area of lower brightness at this location.

Said prisms 143 are located on the outlet face 141b, on the side opposite to that where the connecting bridge 142 is joined to the inlet face 141a. In a nonlimiting embodiment illustrated in FIG. 6a, said prisms 143 have the same thickness e as said at least one connecting bridge 142. This makes it possible to recover all of the light rays R1 coming from the connecting bridge 142.

The prisms 143 are oriented so as to refract the light rays R1 coming from the connecting bridge 142 along an axis of movement of the motor vehicle 2, which is parallel to the optical emission axis X. To this end, the prisms 143 s 'extend perpendicular to the main direction Y. It will be noted that the rays R11 seen previously are unfortunately lost.

In a nonlimiting embodiment illustrated in FIG. 5a, the outlet face 141b comprises prisms 143 distributed in two sets 143a, 143b one of which 143a is configured to redirect the light rays R1 coming from the first optical pattern 142a and l the other 143b is configured to redirect the light rays R1 coming from the second optical pattern 142a. Thus, in FIGS. 5a, 6a and 7, the right group 143b redirects the light rays R1 coming from the optical pattern 142a on the left, and the left group 143a redirects the light rays R1 coming from the optical pattern 142a on the right.

Of course, the description of the invention is not limited to the embodiments described above.

Thus, in another nonlimiting embodiment, said light device 1 is an interior lighting device comprising a housing closed by a transparent or translucent glass.

Thus, the invention described has the following advantages in particular:

- It allows the light device to have good uniformity in the distribution of light on the output face 141b of the secondary optical element 141;

- It allows an observer located substantially in the axis of optical emission X to see the light beam without shadows.

Claims (12)

1. Light device (1) for a motor vehicle (2), said light device (1) comprising: - a housing (10); - a support (12) comprising at least one light source (13) configured to emit light rays (R); - an optical system (14) configured to form a light beam (F) along an optical emission axis (X) from said light rays (R), and comprising: - a primary optical element (140) disposed partly opposite said at least one light source (13); - a secondary optical element (141) disposed opposite said primary optical element (140), connected with said a primary optical element (140) via at least one connecting bridge (142) and comprising an inlet face (141a) with Fresnel steps (141 c) and an outlet face (141 b); Characterized in that said at least one connecting bridge (142) comprises at least one optical pattern (142a) with an entry face (142b) substantially perpendicular to a part (R1) of the light rays (R) passing through said optical element primary (140). 2. Light device (1) according to claim 1, wherein said at least one optical pattern (142a) projects from said at least one connecting bridge (142). 3. A light device (1) according to claim 1 or claim 2, wherein said at least one optical pattern (142a) forms a fin. 4. Light device (1) according to any one of the preceding claims, in which said at least one optical pattern (142a) is of the same thickness (e) as said at least one connecting bridge (142). 5. Light device (1) according to any one of the preceding claims, wherein said at least one connecting bridge (142) is full. 6. Luminous device (1) according to any one of the preceding claims, in which said outlet face (141b) of said secondary optical element (141) comprises prisms (143) at the level of said at least one connecting bridge (142) so as to straighten along said optical emission axis (X) the light rays (R1) coming from said secondary optical element (141). 7. Light device (1) according to the preceding claim, wherein the prisms (143) are oriented so as to refract the light rays (R1) coming from said at least one connecting bridge (142) along an axis of movement of the motor vehicle (2). 8. Light device (1) according to any one of the preceding claims, in which said light device (1) comprises a plurality of light sources (13) and a plurality of connecting bridges (142), a connecting bridge (142 ) being surrounded by two light sources (13). 9. Light device (1) according to the preceding claim, in which each connecting bridge (142) comprises two optical patterns (142a) of which: - A first optical pattern (142a) with an input face (142b) perpendicular to a part (R1) of the light rays (R) emitted by one of the two light sources (12) surrounding said connecting bridge (142) ; and - a second optical pattern (142a) with an input face (142b) perpendicular to a part (R1) of the light rays (R) emitted by the other of the two light sources (13). 10. Light device (1) according to claim 6 and claim 9, wherein the prisms (143) are distributed in two sets (143a, 143b) one of which (143a) is configured to redirect the light rays (R1) from the first optical pattern (142a) and the other 5 (143b) is configured to redirect the light rays (R1) from the second optical pattern (142a). 11 .Light device (1) according to any one of the preceding claims, in which the optical system (14) is made of synthetic polymer material. 10 12.Light device (1) according to any one of the preceding claims, wherein said light device (1) is a raised brake light.