WO2023099506A1

WO2023099506A1 - Lighting device comprising an array of light-emitting elements for a motor vehicle

Info

Publication number: WO2023099506A1
Application number: PCT/EP2022/083746
Authority: WO
Inventors: Alexandre Val; Pengcheng HU
Original assignee: Valeo Vision
Priority date: 2021-11-30
Filing date: 2022-11-29
Publication date: 2023-06-08
Also published as: FR3129705B1; FR3129705A1

Abstract

Disclosed is a lighting device (1) for a motor vehicle, comprising: - a luminescent display panel (5) comprising an array of light-emitting elements and at least one control circuit (16) for controlling the light-emitting elements; - a housing (3) within which the display panel (5) is placed; - a support (7) secured to the housing (3) and to which the display panel is secured, the support being configured to discharge the heat produced by the display panel, the support comprising a first portion (7A) inside the housing, the first portion being provided with a face (24) in direct or indirect contact with the at least one control circuit, the support comprising a second portion (7B) outside the housing for dissipating heat outside the housing.

Description

Title of the invention: Luminous device for a motor vehicle comprising a matrix of light-emitting elements

Technical field of the invention

[1] The invention relates to the field of lighting devices for motor vehicles. More specifically, the invention relates to a luminous device comprising a luminous display screen comprising a matrix of light-emitting elements.

State of the prior art

[2] Motor vehicles conventionally carry various lights making it possible to illuminate the road and/or to be clearly seen by other motorists. These lights also make it possible to provide information on the direction and/or the speed followed by the vehicle to motorists positioned behind the vehicle. Thus, flashing lights indicate an intention to turn and stop lights indicate a braking action of the vehicle. It is desirable to increase the quantity and the quality of the information provided by a vehicle to other motorists, in particular to motorists positioned at the rear of the vehicle. To this end, vehicles equipped with a light device comprising a display screen provided with a matrix of light-emitting elements are known.

[3] Such luminous devices must meet many technical requirements, including:

- they must remain below a critical operating temperature even when all the light-emitting elements of the matrix are switched on simultaneously.

- they must be both robust with regard to electromagnetic disturbances and not themselves generate electromagnetic disturbances which could disturb the operation of other electronic equipment of the vehicle.

- they must be compact so as to integrate easily and harmoniously into the silhouette of the vehicle.

- the display screens must offer the largest possible display surface, without loss of space.

- Finally, they must be resistant to mechanical stresses, in particular vibrations, linked to the use of the vehicle.

[4] The luminous devices known from the state of the art do not make it possible to achieve all of these requirements at the same time.

Presentation of the invention

[5] The object of the invention is to provide a light device remedying the above drawbacks and improving the light devices known from the prior art.

[6] More specifically, a first object of the invention is to provide a luminous device comprising a display screen provided with a matrix of light-emitting elements which allows efficient evacuation of the heat produced. [7] A second object of the invention is to provide a light device equipped with a display screen having a large display surface.

[8] A third object of the invention is to provide a light device that is compact, resistant to mechanical stress and electromagnetic stress.

Summary of the invention

[9] The invention relates to a lighting device for a motor vehicle comprising:

- a luminous display screen comprising a matrix of light-emitting elements and at least one circuit for driving the light-emitting elements, the light-emitting elements being arranged on a first face of the display screen, the at least one driving circuit being arranged on a second face of the display screen, the second face being opposite the first face, the display screen comprising at least one floating edge,

- a box inside which the display screen is arranged, the box being configured to be fixed to a body part of a motor vehicle,

- a support fixed to the housing and on which the display screen is fixed, the support being configured to evacuate the heat produced by the display screen, the support comprising a first part inside the housing, the first part being provided with a face in direct or indirect contact with the at least one control circuit, the support comprising a second part outside the casing to dissipate heat outside the casing.

[10] The light device, in particular its housing, can be configured to be fixed to a rear wing of a motor vehicle or to a trunk door of a motor vehicle, and/or to the front of a motor vehicle , and/or to a side part of a motor vehicle, and/or inside the passenger compartment of a motor vehicle.

[11] The light device can for example be configured to display a light function for automotive lighting or signaling, and/or a pictogram, in particular a pictogram corresponding to information on a state of the vehicle, and/or a traffic state surrounding the vehicle, and/or a state of the road on which the vehicle is moving, such as the presence of rain, snow, ice, an obstacle, or a degraded or damaged area, and/or a emblem of recognition of the vehicle or the vehicle manufacturer, such as a brand logo.

[12] The second part of the support may comprise a heat exchanger, in particular a set of cooling fins.

[13] The housing may comprise a wall sandwiched between the first part of the support and the second part of the support.

[14] The light device may comprise a first electronic card electrically connected to the at least one control circuit, the electronic card being positioned outside the housing and fixed to the second part of the support.

[15] The second part of the support can cover the first electronic card so as to form electromagnetic shielding of the first electronic card. [16] The light device may comprise an electrical connection means connecting the display screen to the first electronic card, the electrical connection means comprising a second electronic card electrically connected to a first electrical connector arranged on the second face of the display screen, the second electronic card being positioned inside the case and fixed to the first part of the support, the second electronic card being connected to the first electronic card via a second electrical connector and a third electrical connector connected to each other, the second electrical connector being arranged on the second electronic card, and the third electrical connector being arranged on the first electronic card.

[17] The first electronic card can extend against a wall of the housing.

[18] The first part of the support and the second part of the support can be two separate elements fixed to each other, in particular by screwing and/or by gluing.

[19] The first part of the support and the second part of the support can form a one-piece assembly.

[20] The display screen may comprise one or more studs projecting from the second face, each stud comprising a blind and tapped opening, the support comprising one or more pillars facing each stud, each pillar comprising further a through opening cooperating with an opening of a stud and with a screw to fix the display screen to the support.

[21] The array of light emitting elements may be a passive array of light emitting elements or an active array of light emitting elements.

The light-emitting elements can be mini-LEDs or micro-LEDs.

The array of light emitting elements may include at least 10,000 light emitting elements.

Each pilot circuit can be able to control the selective ignition of at least 3000 light-emitting elements.

The display screen may comprise a substrate on which is arranged the matrix of light-emitting elements, the substrate being made of glass or the substrate being a printed circuit board.

[22] Said face of the first part of the support may be in contact with the at least one control circuit by means of an electrically insulating and thermally conductive glue.

[23] The display screen may comprise a substrate provided with a thermal interface, the thermal interface being arranged on the second face of the display screen, said face of the first part of the support being in direct contact or indirect with the thermal interface.

[24] Said face of the first part of the support may extend in a plane substantially parallel to a plane of the display screen, said face of the first part of the support comprising a perimeter whose shape is inscribed in the shape of a perimeter of the display screen.

[25] The support may comprise a peripheral edge, continuous or discontinuous, in electrical contact with a perimeter of the display screen.

Presentation of figures

[26] Figure 1 is a perspective and front view of a light device according to a first embodiment of the invention.

[27] Figure 2 is a schematic sectional view of the light device of Figure 1.

[28] Figure 3 is a perspective and rear view of a display screen of the light device of Figure 1.

[29] Figure 4 is a perspective and front view of a support of the light device of Figure 1.

[30] Figure 5 is a schematic sectional view of a light device according to a second embodiment of the invention.

detailed description

[31] Figure 1 illustrates a light device 1 according to a first embodiment of the invention. The luminous device 1 is integrated into a motor vehicle, an element 2 of which is represented in FIG. 1. The element 2 of the vehicle can be, for example, a part of the bodywork of the vehicle. In particular, the light device 1 is a rear light device, ie it is arranged at the rear of the vehicle. The light device can for example be integrated into a left rear wing, a right rear wing or else into a trunk door of the vehicle. The light device is capable of producing and emitting light rays towards the rear of the vehicle so as to make the vehicle clearly visible to motorists positioned behind the vehicle, but also so as to transmit information to these motorists.

[32] To facilitate the description and understanding of the figures, an orthogonal reference frame formed of the X, Y and Z axes is defined as follows: The X axis is an axis parallel to a longitudinal axis of the vehicle, i.e. say the axis in which the vehicle is moving in a straight line. The X axis is oriented from the front to the rear of the vehicle. The Y axis is an axis parallel to a transverse axis of the vehicle. It is oriented from left to right according to the driver's point of view when seated in the normal driving position in the vehicle. The X and Y axes are perpendicular to each other and parallel to the plane on which the vehicle is resting. It is assumed that the vehicle rests on a horizontal plane. The Z axis is a vertical axis. The Z axis is perpendicular to the X and Y axes. The terms "lower" and "upper" qualify a positioning relative to the vertical axis. As a side note, as the luminous device is a rear luminous device, it comprises a main direction of illumination oriented globally towards the rear, that is to say at least roughly in the direction of the axis X. As a variant, the embodiment presented could be adapted to equip a light device intended to be integrated into the front of a motor vehicle. [33] The light device comprises a housing 3 closed by a glass 4 transparent or translucent through which light rays can pass. The light device is fixed directly or indirectly to a body element. In particular, the casing 3 can comprise fixing means such as for example openings to allow the fixing of the luminous device to the vehicle. The housing 3 can, for example, be made of plastic.

[34] The light device 1 comprises a light display screen 5, and a support 7 on which the display screen 5 is fixed. The display screen 5 is arranged, in other words positioned, inside of the housing 3. As is clearly visible in FIG. 1, the display screen 5 comprises a substantially polygonal shape: it comprises a set of rectilinear edges 8, 9 connected by vertices. The display screen extends in a plane P which is at least roughly perpendicular to the axis X. More precisely, as can be seen in FIG. 2, the plane P forms with the plane YZ, defined by the axes Y and Z, a non-zero angle Al, of the order of a few degrees or a few tens of degrees. The plane P is thus slightly inclined upwards, which makes it possible to orient the display screen in the line of sight of an observer or a motorist positioned above the level of the luminous device 1.

[35] Among the edges 8, 9 forming the outline of the display screen 5, there are on the one hand floating edges 8, or in other words free edges, and on the other by hidden edges 9, or in other words technical edges. The floating edges 8 are not covered by any component of the light device and are visible through the glass 4. On the contrary, the masked edges 9 are covered by other elements of the light device, in particular by a mask 6, and are not not visible through glass 4. Masked edges 9 may be in contact with other components of the light device.

[36] According to the embodiment shown, the display screen mainly comprises an upper edge, a lower edge and two side edges on the right and on the left. The upper edge as well as the upper ends of the side edges form a single hidden edge 9. The other edges of the display screen, in particular the bottom of the side edges and the lower edge of the display screen form the floating edge 8. Display screen 5 therefore comprises a visible part 10 through crystal 4 and a masked part 11. A limit L separating the visible part from the masked part is represented by a dotted line in FIG. 3. As a variant, the display screen could include a second masked edge, or even a third masked edge provided that it includes at least one floating edge representing 50% of the periphery of the screen. At least one masked edge could be arranged on a side side of the display screen and/or on a bottom side of the display screen. According to another embodiment, the display screen could include no masked edge, that is to say that the entire periphery of the display screen would be visible through glass 4. The display screen would thus be mounted completely floating in the light device 1. [37] Mask 6, which could also be called "style support", is positioned directly behind display screen 5. Mask 6 is therefore visible through glass 4 along floating edges of the display screen 4. The mask 6 makes it possible to obtain a contrasting background which improves the visibility of the display screen while providing support for ornaments of the light device. As can be seen in FIG. 1, these ornaments can be made with ribs 13. These ribs contribute both to the aesthetics of the mask and to its rigidity. In addition, the mask 6 hides any other element of the light device positioned behind it.

[38] The display screen 5 comprises a matrix of light-emitting elements, that is to say a set of light-emitting elements forming a grid arranged in rows and columns. The number of light-emitting elements on each row or on each column is not necessarily identical. Thus, the matrix of light-emitting elements can take any shape such as a polygonal shape. The electroluminescent elements can be distributed over the whole of the visible part 10 of the display screen, up to the floating edge 8. More precisely, the display screen can comprise a strip along the floating edge 8 which is devoid of light-emitting element and whose width is advantageously between 0.3mm and 3mm, for example of the order of approximately one millimeter. The light-emitting elements are arranged on a first face 14 of the display screen 5 facing the crystal 4, so as to make them visible from outside the vehicle. The light rays produced by the light-emitting elements are emitted directly towards the lens 4, without being reflected or shaped by a lens or any other optical component.

[39] Light-emitting elements are components capable of emitting light rays when an electric current passes through them. In particular, the light-emitting elements can be mini-LEDs, that is to say light-emitting diodes with a dimension of less than 350 μm on a side. The light-emitting elements can even be micro-LEDs, that is to say light-emitting diodes with a side dimension of less than 80 μm. Each electroluminescent element can be turned on or off individually and thus forms a pixel of an image displayed on the display screen 5. This image can be for example a pictogram or a symbol such as a letter or a number. This image can also be composed of a word or even a set of words. Each electroluminescent element can emit monochrome light rays or, conversely, of different colors.

[40] The display screen comprises a substrate 15 on which is arranged the matrix of light-emitting elements. This substrate extends globally in a plane and has a thickness of the order of 500 μm or one millimeter. When the substrate is a printed circuit board, electrical connections with the light-emitting elements can be established through the thickness of the substrate. The screen can be obtained by laser cutting after the light-emitting elements have been assembled on the first face 14 as well than other electronic components on its opposite side. The cutting occurs after all the electrical and optical tests necessary to verify the proper functioning of the screen.

[41] Alternatively, the substrate 15 may for example be made of glass or ceramic. In this case, electrical connections can be established in the thickness of the substrate. The thickness of the substrate is then advantageously between 100 μm and 500 μm in order to make it possible to produce metallized through-holes between the two faces of the substrate.

[42] In some cases, no electrical connection can be established within the thickness of the substrate. The electrical connection of the light-emitting elements is then obtained by electrical connection means bypassing the substrate at the level of at least one of its edges. It is then preferable for the display screen 5 to include at least one masked edge so as to hide the electrical connection means of the light-emitting elements. Advantageously, this masked edge can be specified for any type of substrate.

[43] The light emitting element array may be a passive light emitting element array or an active light emitting element array. In an active matrix of light-emitting elements, the ignition of each light-emitting element is controlled by an ignition circuit specific to it. In a passive array of light emitting elements, the light emitting elements are electrically connected to their neighbors. The selective ignition of an electroluminescent element is obtained by activating the passage of an electric current in a column and in a row of the matrix.

[44] The display screen 5 further comprises at least one driver circuit 16 configured to selectively turn on one or more light-emitting elements. The at least one driver circuit 16 is arranged on a second face 17 of the display screen, the second face 17 being opposite the first face 14. The second face 17 is therefore a face not visible through the glass 4. It is represented in particular in FIG. 3. According to the embodiment shown, the light device comprises eight separate driver circuits 16, however this number could be different. The driver circuits 16 are distributed over the second face 17 of the display screen 5. Each driver circuit can be integrated into a case of substantially parallelepiped shape. The thickness of these casings along an axis perpendicular to the plane P can be of the order of one millimeter. The width and the length of these casings along axes parallel to the plane P can be of the order of ten millimeters. These boxes therefore protrude with respect to the substrate 15 on which they are fixed.

[45] Each driver circuit can be configured to control a given number of light-emitting elements, for example of the order of 3000, or even 4000 light-emitting elements. Each driving circuit can in particular be configured to drive up to 4096 light-emitting elements. This value corresponds to 2 raised to the power of 12, which is a simple configuration to implement. So the matrix of light-emitting elements may comprise at least 10,000 light-emitting elements, or even at least 20,000 light-emitting elements, or even at least 30,000 light-emitting elements. The light device is thus capable of displaying a very high resolution image. For example, for a matrix having a rectangular shape with a dimension of 200mm by 80mm, and for a pitch of 350pm between the center of two adjacent light-emitting elements, the total number of light-emitting elements is approximately 130,000. It will then be possible to use 32 circuits driver to drive all of these light-emitting elements. It should be noted that this value is given for monochrome light-emitting elements, that is to say emitting a single color, for example red or amber. Each electroluminescent element can also be configured to emit several colors, in particular RGB for red/green/blue (Red/Green/Blue in English). Each electroluminescent element then comprises a plurality of emitters, each corresponding to one of the colors emitted. Each electroluminescent element can comprise a single emitter for each color. For example, an RGB electroluminescent element may comprise an emitter for red, one for green and one for blue, in particular a single emitter for each of the colors. Each driving circuit is adapted to drive components, that is to say light-emitting elements and/or emitters, of a given color. Thus, in the case where several colors are emitted, this can lead to an increase in the number of piloting circuits necessary. For example, for a given number of light-emitting elements, three times more driver circuits are required in the RGB case with three emitters per light-emitting element, than for the same number of monochrome light-emitting elements. An alternative for having several colors is to use only monochromatic electroluminescent elements, divided into several batches each dedicated to one of the colors. In this case, the light-emitting elements of the different batches are advantageously interleaved. Thus, any portion of the surface of the screen, of square shape and of a size corresponding to a few light-emitting elements, for example a number of light-emitting elements corresponding to two or three times the number of colors, is able to emit all the colours. It is then possible to obtain a screen capable of emitting all the colors over its entire surface. The brightness of the display screen can be at least equal to 4000 Cd/m2, or even at least 5000 Cd/m2 for wavelengths around 640 nm providing a dark red color. In a lower wavelength in the red, this luminosity can be greater than 10000 Cd/m ² or even greater than 15000 Cd/m ² . The red color is obtained for a wavelength between 609nm and 780nm. Other colors are possible, such as white, or amber. The amber color is obtained for wavelengths between 587nm and 597nm. In operation, the heat dissipated by all the elements electroluminescent and by the driver circuits can reach of the order of several watts, for example between 5 and 10 watts.

[46] In connection with Figures 2 and 3, it is observed that the control circuits 16 of the display screen 5 are electrically connected to an electronic control board 18 via an electrical connection means 19 , in particular an electrical sheet. This electronic card 18 can itself be connected upstream to an energy source of the vehicle and in particular to an on-board computer. The tablecloth, also called flexboard, is a flexible printed circuit. As a variant, this electrical connection means 19 could take a different form such as an electrical cable or a set of electrical cables arranged in a bundle. The electrical connection means 19 is connected to the display screen 5 via a connector 20 positioned at its masked edge 9. The electrical connection means 19 therefore remains invisible through the glass 4.

[47] The support 7 is particularly clearly visible in Figures 2 and 4. The support 7 combines several functions including maintaining the position of the display screen 5, the evacuation of the heat produced by the screen of display 5 and the electromagnetic protection of the display screen 5. For this purpose, the support 7 is advantageously a piece of metal, in particular aluminum. The support 7 comprises a first part 7A positioned inside the casing 3 and a second part 7B positioned outside the casing. The first part 7A of the support is configured to support the display screen 5. The second part 7B is configured to dissipate the heat produced by the display screen 5.

[48] According to the first embodiment presented, the first part 7A and the second part

7B are two separate pieces attached to each other. The first part 7A and the second part 7B comprise a set of surfaces 46 in contact in order to allow heat transfer from the first part 7A to the second part 7B. The surfaces 46 therefore form thermal bridges between the first part 7A and the second part 7B of the support. The first part 7A can be in direct or intimate contact with the second part 7B (that is to say without any element interposed between these two parts) or in indirect contact, for example by means of a conductive paste of the heat. The use of such a paste makes it possible to overcome any lack of flatness between the respective surfaces of the first part 7A and of the second part 7B and thus guarantee a large heat exchange surface between the first part and the second part. Whether it is a direct or indirect contact, this contact is provided to allow heat transfer (or in other words heat evacuation) from the display screen 5 to the second part 7B of the support. It should be noted that the notion of direct or indirect contact applies to other elements, when a heat exchange between these elements is desired.

[49] The support 7 is fixed to the housing 3. For this purpose several fixing means can be considered. Referring to Figure 2, the fixing of the support 7 to the housing 3 can be obtained by clamping a wall 47 of the housing 3 between the first part 7A and the second part 7B of the medium. The two parts 7A, 7B can be clamped together, for example by screwing. Such a fixing means makes it possible to secure the two parts 7A and 7B of the support together while fixing the support 7 to the box 3. The wall 47 is a partition of the box positioned behind the display screen 5. The wall 47 can be extend substantially perpendicular to the X axis. It comprises sufficient rigidity to support the support 7 and the display screen 5 fixed to the support. In addition, the wall 47 comprises a set of openings 48 through which the first part 7A and/or the second part 7B of the support extend to allow contact between these parts. These openings 48 are positioned behind the display screen 5 and can have any shape. As can be seen in FIG. 2, the first part comprises protuberances 49 or crenellations which extend through the openings 48 to come into contact with a flat surface of the second part 7B. The openings 48 have a shape identical to the shape of the protrusions 49. As a variant, these protrusions or slots could be formed in the second part 7B and come into contact with a flat surface of the first part 7A. In Figure 2, three protrusions 49 are shown, however, this number could be any number. The number and the surface of the protuberances can be adapted so as to obtain the best compromise between a large contact surface between the first part 7A and the second part 7B to ensure good heat transfer towards the outside of the casing 3 and a number or a limited area of the openings 48 in the wall 47 of the case so that the latter retains sufficient rigidity to support the support 7 and the display screen 5.

[50] Alternatively other means of fixing the two parts 7A and 7B of the support between them or the support 7 on the housing 3 could be considered. For example, the first part 7A could be glued to the second part 7B by means of a heat-conducting glue. According to another variant, the two parts 7A, 7B could be fixed to one another by interlocking or by hooping. Finally, other techniques such as crimping, clipping, or fixing by magnetic means could be envisaged.

[51] The first part 7A of the support 7 comprises a face 24 extending parallel to the plane P. This face 24 comprises first zones 25 intended to come into direct or indirect contact with the control circuits to evacuate the heat that the latter produce during their operation. As seen previously, a direct contact is established when the support 7 is in intimate contact with the casing containing the pilot circuit 16, without an intervening element. An indirect contact is established when the support 7 is in contact with the casing enclosing the pilot circuit 16 by means of a heat-conducting element, in particular by means of an electrically insulating and thermally conductive adhesive. The use of such an adhesive is advantageous in that it makes it possible to guarantee a large contact surface between the support 7 and the control circuits 16 while forming a fixing means between the support 7 and the screen of display 5. The first zones 25 can possibly be provided in depression or in relief with respect to a reference plane of the face 24.

[52] Advantageously, the support 7 is also in direct or indirect contact with the substrate. As is clearly visible in FIG. 5, the second face 17 of the display screen 5 comprises a thermal interface 26 in the shape of an L, and positioned substantially towards the center of the second face. This thermal interface 26 is also in direct or indirect contact with the support 7. For this purpose, the support 7 comprises a second zone 27 of a shape substantially identical to the shape of the thermal interface 26. This second zone can be provided projecting with respect to the reference plane of the first zone 12. As a variant, the display screen could comprise any number of thermal interfaces and these could adopt any geometric shape. The direct or indirect contact of the support on the substrate makes it possible to cool the light-emitting elements by thermal conduction. In the embodiment presented, the positioning of the thermal interface 26 towards the center of the display screen is advantageous because the light-emitting elements of the center of the display screen are generally activated more often and the heat than they dissipate is more difficult to evacuate.

[53] Advantageously, heat exchange surfaces are located at the level of the electronic components, for example at the level of the control circuits 16 to extract the thermal energy, but also on surfaces of the second face 17 not populated by electronic components. . Thus, the heat transfer is optimized.

[54] The face 24 of the first part 7A of the support 7 further comprises a perimeter whose shape is inscribed in the shape of a perimeter of the display screen 5. Thus, the support 7 remains hidden behind the display screen 5. According to the embodiment described, the first face of the support comprises a circumference of shape substantially identical to the shape of a circumference of the display screen. Thus, the support 7 remains hidden by the display screen 5 while providing a maximum contact surface with the display screen. Therefore, face 24 also includes a polygonal shape with straight sides connected by vertices. The edge of the support 7 can even be beveled to make the support invisible regardless of the angle from which the luminous device is observed through the glass. According to another embodiment, the periphery of the support could be smaller than the periphery of the display screen. The support could then have a shape substantially homothetic to that of the display screen or even a different shape from the display screen. In an advantageous embodiment, the periphery of the support is configured so that the support is in contact with all the pilot circuits, in order to ensure good heat dissipation.

[55] In addition, the support 7 comprises a cutout 28 arranged at its upper edge, substantially in the center of the upper edge. This cutout 28 comprises a shape substantially complementary to that of the connector 20. This cutout 28 makes it possible to avoid interference between the support 7 and the connector 20 and facilitates the connection operation electrical connection of the electrical connection means 19 to the connector 20. The absence of contact of the support 7 against the connector 20 is not a problem because the connector 20 is not an element likely to heat up considerably.

[56] Furthermore, the support 7 comprises means for positioning the display screen. These positioning means block the display screen in rotation and in translation in the plane P. In this case, these positioning means are formed by two lugs 29 cooperating respectively with two openings 30 of the display screen positioned on either side of the connector 20. The lugs 29 and the corresponding openings 30 are therefore positioned in the hidden part of the display screen. They are therefore not visible through the glass 4.

[57] The support 7 also includes a peripheral flange 31, projecting from the face 24, and in electrical contact with a perimeter of the display screen 5. The flange 31 forms a bead at the periphery of the support and has a substantially constant section. On the principle of a Faraday cage, this rim 31 forms a shield against electromagnetic waves. For this purpose, the flange 31 can be continuous or discontinuous. According to the embodiment presented, the flange 31 comprises a discontinuity at the level of the upper edge and two discontinuities at the level of the lower edge of the support. The presence of discontinuities allows better air circulation between the face 24 of the support and the second face 17 of the display screen. The electromagnetic protection obtained makes it possible to block the electromagnetic waves emitted by the display screen so as not to disturb the operation of other electronic equipment of the vehicle and also forms a barrier preventing external electromagnetic waves from disturbing the operation of the display screen. Furthermore, as the rim 31 rests on the periphery of the display screen, it forms a means of orienting the display screen. The combination of the two lugs 29 and the rim 31 therefore makes it possible to precisely define the position and the orientation of the display screen. Incidentally, part of the heat generated by the display screen can be transferred to support 7 via rim 31.

[58] The second part 7B of the support 7 comprises a heat exchanger, that is to say a member configured to dissipate the heat accumulated by the support 7. In particular, this heat exchanger comprises a set of cooling fins 50 . These fins extend into the air and provide a large contact surface with the air compared to the volume they occupy. According to the embodiment presented, the fins extend perpendicular to the wall 47 of the housing 3. The fins 50 are attached to a common base 51 which extends parallel to the wall 47 and by which the first part 7A is fixed to the second part 7B.

[59] As is clearly visible in Figure 2, the electronic card 18 is positioned outside the housing 3, that is to say on the other side of the wall 47 with respect to the screen d display 5. Thus, the heat produced by the electronic card 18 during its operation does not contribute to heating the interior volume of the box 3. The first electronic card 18 extends against a wall of the box, parallel to the wall 47. Thus, the electronic card 18 does not increase or only slightly increases the overall size of the light device. Advantageously, the electronic card 18 is fixed to the second part 7B of the support 7. In other words, the second part 7B of the support 7 also serves as a support for the electronic card 18. The electronic card 18 can thus be effectively cooled: in particular, the heat exchanger integrated in the second part 7B can dissipate the heat produced by the electronic card 18.

[60] The second part 7B of the support 7 can cover the electronic card 18 so as to form electromagnetic shielding of the latter. For example, the second part 7B can comprise a housing whose shape corresponds to the shape of the electronic card and inside which the electronic card 18 is positioned. According to one embodiment, only one of the two faces of the electronic card 18 can be covered by the second part 7B of the support 7. According to another embodiment, the two opposite faces of the electronic card 18 can be covered by the second part 7B of the support 7. In this case, the electronic card 18 can be assembled to the second part 7B of the support by a slot provided on one of the sides of the support 7. In general, the second part 7B of the support advantageously comprises dimensions in the plane comprising the Y and Z axes which are greater or equal to the dimensions of the electronic board 18.

[61] According to another original aspect of the invention, the electrical connection means 19 connecting the display screen 5 to the electronic card 18, called the first electronic card 18, comprises a second electronic card 52. The second electronic card 52 is electrically connected to the electrical connector 20, said first electrical connector. The second electronic card 52 is positioned inside the casing 3 and fixed to the first part 7A of the support 7. The second electronic card 52 is electrically connected to the first electronic card 18 via a second electrical connector 53 and a third electrical connector 54. The second electrical connector 53 is arranged, in particular fixed, on the second electronic card 52 and the third electronic connector is arranged, in particular fixed, on the first electronic card 18. The second electrical connector 53 is connected to the third electrical connector 54.

[62] The second electronic card 52 may have dimensions substantially corresponding to the dimensions necessary to integrate the second electrical connector 53 therein. The second electronic card 52, the second electrical connector 53, and the third electrical connector 54 may form a superimposed structure which is positioned at the interface between the first part 7A and the second part 7B of the support 7, in particular in a housing formed inside one of the protrusions 49. This superimposed structure can in particular be positioned at the height of one of the openings 48 provided in the wall 47 of the box 3. Advantageously, this superposed structure is surrounded by the first part 7A and/or by the second part 7B which thus form electromagnetic shielding.

[63] As a side note, as shown in Figure 1, the light device further comprises different compartments Cl, C2, C3 in which are arranged light sources providing different light functions. By light function, we understand here a lighting and/or signaling function, in particular taken from a lantern light, a position light, a flashing light, a brake light, a reversing light, a fog light, a daytime running light also called DRL (Daytime Running Lamp in English), a side light such as a side-marker, a low beam or a high beam. By misuse of language, the light function and the device making it possible to ensure this light function are referred to here in the same way. A first compartment Cl, occupying most of the volume of the light device, receives the display screen 5. A second compartment C2, positioned in the upper part of the light device, receives a flashing light, that is to say a regulated light source used to indicate to other motorists an intention of the vehicle to turn right or left. A third compartment C3 receives a brake light, that is to say a regulated light source used to indicate to other motorists an activation of a braking system of the vehicle. The flashing and stop lights are given solely by way of non-limiting examples. Any other light function mentioned above can also take place in one of the compartments C2 or C3. In addition, the light functions can be different or identical between these two compartments. The third compartment C3 is positioned vertically above the second compartment C2. The compartments C2 and C3 are positioned substantially opposite the masked part 11 of the display screen 5. It is precisely these compartments C2 and C3 which hide the masked part 11 of the screen. Compartments Cl, C2 and C3 are isolated from each other by a set of walls. Advantageously, these walls form separations blocking the light rays so that the light rays emitted in a given compartment do not disturb the operation or the appearance of the light sources arranged in the other compartments. As a variant, the luminous device could comprise any other number of compartments. In particular, the light device could comprise only a first and a second compartment, the display screen being arranged in the first compartment, the flashing light and/or the brake light being arranged in the second compartment. A compartment may itself be subdivided into several sub-compartments.

[64] Figure 5 illustrates a second embodiment of the invention. We only attempt to describe the differences of the second embodiment compared to the first embodiment of the invention. In FIG. 5, the elements common to the first embodiment are designated with the same references. The first part 7A of the support comprises one or more pillars 54 extending parallel to the axis X. These pillars 54 support the display screen 5 and conduct the heat produced by the display screen 5 towards the second part 7B of the support 7. The pillars 54 are connected to a common base 58 which extends parallel to the wall 47. As before, the contact between the first part 7A and the second part 7B of the support can be an indirect contact, that is to say by means of a heat-conducting paste or a direct contact.

[65] The display screen 5 can be fixed to the support 7 in different ways. For example, the end of one or more pillars 54 can be glued by means of a heat-conducting adhesive to a pilot circuit 16 or to a thermal interface 26. The two parts 7A and 7B of the support are fixed together by screwing. The wall 47 is thus clamped between the two parts 7A and 7B of the support, which makes it possible to immobilize the support relative to the housing. More precisely, fixing screws 59 engage with base 51 and with base 58. Fixing screws 59 thus pass through wall 47 which is then sandwiched between the two parts 7A and 7B of the support. Advantageously the screws 59 comprise screw heads positioned on the side of the second part 7B of the support, which facilitates their handling. The screws 59 can possibly pass through openings 60 provided in the electronic card 18. The heads of the screws 59 can also be covered by the electronic card 18. Finally the screws can possibly extend into one or more pillars 54.

[66] Finally, a luminous device is obtained equipped with a display screen that is particularly compact and also simple to assemble because it comprises a limited number of elements, each element combining various functions. The display screen is attached to the bracket and the bracket is attached to the housing. The assembly thus obtained is robust and in particular resistant to the vibrations to which the vehicle is subjected. The lighting device is also particularly aesthetic. No electrical connection or fixing element is made visible through the glass 4. Finally, the only elements visible through the glass are on the one hand the display screen which offers a large display surface due to its floating edges, and on the other hand the mask which is easily customizable and provides support for various ornaments.

[67] When the luminous device operates, the heat generated by the light-emitting elements is effectively evacuated away from the display screen via its support. The display screen can thus remain below a critical operating temperature. In addition, the bracket provides electromagnetic shielding, which guarantees stable operation of the light device and other electronic devices on board the vehicle.

Claims

[Claim 1] Luminous device (1) for a motor vehicle comprising:

- a luminous display screen (5) comprising a matrix of light-emitting elements and at least one pilot circuit (16) of the light-emitting elements, the light-emitting elements being arranged on a first face (14) of the display screen , the at least one driver circuit being arranged on a second face (17) of the display screen, the second face being opposite the first face, the display screen comprising at least one floating edge (8 ),

- a box (3) inside which the display screen (5) is arranged, the box being configured to be fixed to a body part (2) of a motor vehicle,

- a support (7) fixed to the case (3) and on which the display screen is fixed, the support being configured to evacuate the heat produced by the display screen, the support comprising a first part (7A) inside the case, the first part being provided with a face (24) in direct or indirect contact with the at least one pilot circuit, the support comprising a second part (7B) outside the case for dissipate heat outside the case.

[Claim 2] Luminous device (1) according to the preceding claim, characterized in that the second part (7B) of the support (7) comprises a heat exchanger, in particular a set of cooling fins (50).

[Claim 3] Luminous device (1) according to one of the preceding claims, characterized in that the housing (3) comprises a wall (47) sandwiched between the first part (7A) of the support (7) and the second part ( 7B) of the support.

[Claim 4] Luminous device (1) according to one of the preceding claims, characterized in that it comprises a first electronic card (18) electrically connected to the at least one pilot circuit (16), the electronic card being positioned outside the housing and fixed to the second part (7B) of the support (7).

[Claim 5] Luminous device (1) according to the preceding claim, characterized in that the second part (7B) of the support (7) covers the first electronic card (18) so as to form electromagnetic shielding of the first electronic card.

[Claim 6] Luminous device (1) according to one of Claims 4 or 5, characterized in that it comprises electrical connection means (19) connecting the display screen (5) to the first electronic card ( 18), the electrical connection means comprising a second electronic card (52) electrically connected to a first electrical connector (20) disposed on the second face (17) of the display screen, the second electronic card being positioned at the inside the case (3) and fixed to the first part (7A) of the support (7), the second electronic card being connected to the first electronic card (18) via a second electrical connector (53) and a third electrical connector (54) connected to each other, the second electrical connector (53) being arranged on the second electronic board (52), and the third electrical connector (54) being arranged on the first electronic board (18).

[Claim 7] Luminous device (1) according to one of the preceding claims, characterized in that the first part (7A) of the support (7) and the second part (7B) of the support are two distinct elements fixed one to the other, in particular by screwing and/or by gluing.

[Claim 8] Luminous device (1) according to one of the preceding claims, characterized in that the display screen (5) comprises a substrate (15) provided with a thermal interface (26), the thermal interface being arranged on the second face (17) of the display screen, said face (24) of the first part (7A) of the support (7) being in direct or indirect contact with the thermal interface.

[Claim 9] Luminous device (1) according to one of the preceding claims, characterized in that the said face (24) of the first part (7A) of the support (7) extends in a plane substantially parallel to a plane of the display screen (5), said face (24) of the first part of the support comprising a perimeter whose shape is inscribed in the shape of a perimeter of the display screen.

[Claim 10] Luminous device (1) according to one of the preceding claims, characterized in that the support (7) comprises a rim (31) peripheral, continuous or discontinuous, in electrical contact with a perimeter of the screen of display.