Light module of a signaling device of a motor vehicle.

Abstract

The invention relates to a light module (1) of a signaling device of a motor vehicle comprising a plurality of selectively controllable light sources (2), all of the light sources (2) are mounted on the same common support (3) and are encapsulated on this support in a layer of transparent material (4), and in that said layer of transparent material (4) comprises, between each pair of neighboring light sources (2), a first groove (5) filled with at least a first opaque material (51) forming a first wall (52) separating the light sources (2) of said pair. Figure to be published with the abstract: Fig. 1

Description

Title of the invention: Light module of a signaling device of a motor vehicle.

[0001] The invention relates to the field of automotive lighting and light signaling. More specifically, the invention relates to the field of screens integrated into light modules for lighting or light signaling of motor vehicles.

[0002] In the field of automotive signaling, it is known to integrate into light modules of motor vehicles, such as rear lights, screens which can be produced by means of matrices comprising a significant number of light sources.

[0003] The plurality of light sources is generally selectively controllable and comprises sufficiently small dimensions to be able to display on said screens information, which may be in the form of a message or even a pictogram, with an acceptable resolution.

[0004] The information provided by the screens makes it possible to improve the signaling of the motor vehicle, by contextualizing or even accompanying a given signaling function with a message.

[0005] In order to obtain a homogeneous screen appearance, and in particular to avoid perceiving pixels clearly separated from one another, namely the so-called dotted effect according to which the shape of the light sources is perceptible, called the "dotty effect" in English, it is known to reduce the size of the light sources and the pitch separating two neighboring light sources, called the "pitch".

[0006] Beyond the increase in screen resolution that is thus generated, it is therefore possible to reduce the width of the area separating two neighboring pixels. Although this area appears dark, it becomes imperceptible as its width decreases.

[0007] However, it is not possible to reduce the separation pitch below a certain threshold, except by significantly increasing the cost and complexity of producing the screen.

[0008] In this context, in order to maintain good resolution and a uniform lit appearance of the screen, without a “dotty effect”, it is also known to add to the screen an element diffusing the light emitted by each light source to form pixels of dimensions larger than those of the light sources, which then makes it possible to reduce the width of the zone separating two neighboring pixels. The diffusion must also be such that the luminance within each pixel is uniform, and that the screen sharpness and contrast qualities are respected.

[0009] However, the reduction of the pitch between neighboring light sources combined with a diffusion of the light emitted by the light sources can create parasitic effects between the different light sources, in particular neighboring light sources. Indeed, the light emitted by a light source can, if the pitch separating them is reduced, overflow onto the pixel produced by a neighboring light source.

[0010] This effect, also called "cross-talk", has the effect of reducing the screen resolution. In fact, the pixels generated by neighboring light sources partially overlap and it is therefore no longer possible to manage these pixels independently of each other.

[0011] In order to be able to respond to these different constraints, it is known to equip the screen with a grid whose walls define cells each containing a light source. It is thus possible to reduce the pitch between the light sources, to retain the diffusing element and to avoid cross-talk, the light emitted by a light source remaining confined by the walls of the cell containing this light source so that it does not overflow onto a neighboring pixel.

[0012] However, the question of the design and assembly of the screen arises. Indeed, the reduction in the dimensions of the light sources and the pitch separating two neighboring light sources makes the assembly of the grid with the matrix of light sources complex. Indeed, taking into account the manufacturing tolerances of the grid and of this matrix of light sources as well as the phenomena of differential expansion as a function of temperature, it is possible that certain light sources are found at the level of a wall of the grid, or even outside the cells for which they are intended, during the assembly of the matrix and the grid to form the screen.

[0013] Thus, there is also a need to provide a light module for a motor vehicle, intended to form a screen having good resolution, without a "cross-talk" effect, and a homogeneous lit appearance, without a "dotty effect", and which can be assembled without generating a defect despite the reduction in the dimensions of the light sources and the pitch separating two neighboring light sources.

[0014] The present invention is placed in this context and aims to meet this need.

[0015] For these purposes, the invention relates to a light module of a signaling device The invention relates to a motor vehicle, comprising a plurality of selectively controllable light sources.

[0016] According to the invention, all of the light sources are mounted on the same common support and are encapsulated on this support in a layer of transparent material, and said layer of transparent material comprises, between each pair of neighboring light sources, a first groove filled with at least one first opaque material. forming a first wall separating the light sources of said pair.

[0017] The invention thus proposes to form a first wall separating the light sources, so as to form a grid directly on the support of the light sources or on a substrate extending from this common support. Thus, the fact that each light source is arranged between the first walls makes it possible to create an enclosure in which the light emitted by said light sources is contained, or even reflected, in order to reduce the cross-talk phenomenon. It is thus possible to reduce the dimensions of the light sources as well as the spacing separating two neighboring light sources, while using an element to diffuse the light emitted by each light source, in order to avoid a “dotty effect”.In addition, since the grid is produced by overmolding, it is thus freed from the constraints of positioning the grid in relation to the matrix of light sources during assembly, which could be generated by a variation in the dimensions of the grid due to manufacturing tolerances or a phenomenon of thermal expansion.

[0018] In a preferred embodiment, the layer of transparent material is a transparent silicone resin, or transparent silicone.

[0019] Preferably, the layer of transparent material has a thickness of less than 1 millimeter, or even 0.20 millimeter.

[0020] In a particular embodiment, the first grooves comprise dimensions ranging from 300 to 500 micrometers in width.

[0021] The same common support is a printed circuit board, also called PCB for “Printed Circuit Board”.

[0022] The printed circuit board, or PCB, has a first face and a second face opposite the first face. The light sources are mounted on the first face of the PCB, which faces the outside of the signaling device in which the light module is integrated.

[0023] In a preferred embodiment, the light sources may be arranged on the common support so as to be spaced apart from each other by a distance of less than 1000 micrometers, or even less than 200 micrometers. Here, the term "distance between two light sources" means the distance separating one edge of a light source from the other edge facing it of another light source.

[0024] Preferably, the light module is arranged so that the fill factor of the pixels of the screen, also called in English "fill factor", is greater than 50%, preferably greater than 70%, or even greater than 80%.

[0025] The term “fill factor” means the ratio between the surface area of ​​the pixel for which the luminance is greater than a given percentage, in particular 10%, of the maximum luminance of the pixel and the total surface area of ​​the pixel

[0026] In a particular embodiment, the lateral surfaces of each first wall are in contact with the layer of transparent material.

[0027] The invention therefore proposes to form first grooves filled with opaque material framing the light sources in order to reduce the interference effect from one light source to another by intercepting the light emitted by one light source towards a neighboring light source.

[0028] Therefore, the wall reduces interference or cross-talk effects and increases the efficiency of the light module.

[0029] In the same way, the dimensions of the light sources can be reduced, which allows a reduction in the albedo of the light sources but also a reduction in the spacing separating neighboring light sources.

[0030] In addition, the filling surface can be increased and the pitch reduced in order to reduce the “dotty effect”, namely the fact that the pitch separating two neighboring light sources is visible when the screen is lit.

[0031] In the invention, the light sources may be light-emitting semiconductor chips. The semiconductor may be a gallium nitride, or GaN, capable of emitting, by electroluminescence and in response to an electric current passing through it, rays of blue light. The photoluminescent element may, for example, be in the form of a resin comprising a cerium-doped yttrium aluminum garnet, or CE:YAG, capable of absorbing blue light and, by photoluminescence and in response to the excitation produced by this light, of emitting rays of white light for example. The photoluminescent element is arranged on the generator so that a portion of the blue light rays excites this element so that it emits, by photoluminescence, rays of white light. The other portion of the blue light rays passes through this element.Thus, the light source simultaneously emits, when electrically powered, rays of wavelength in the blue and white spectrum, the light thus formed appearing white to the human eye.

[0032] Advantageously, all of the first grooves of the layer of transparent material are arranged so that all of the first walls, formed by the first opaque material filling said first grooves, form a grid, each light source of said plurality of light sources being arranged in a cell of this grid.

[0033] Thus, the fact that all of the light sources are arranged in cells of this grid makes it possible to create an enclosure in which the light emitted by said light sources is reflected in order to reduce the cross-talk phenomenon.

[0034] According to the invention, each first groove extends in the layer of transparent material so that the first wall formed by the first opaque material filling said first groove extends substantially to the common support.

[0035] Advantageously, the layer of transparent material extends above the upper surfaces of the light sources and in which each first wall formed by the first opaque material filling each first groove extends substantially to the upper surface of said layer of transparent material.

[0036] In a particular embodiment of the invention, the first opaque material is a white-colored material. According to the invention, the white-colored material may be a dielectric material, having a reflection coefficient of between 60 and 99%, in particular substantially equal to 90%. It may, for example, be a silicone resin enriched with titanium dioxide (TiO2). Where appropriate, each wall made of the white-colored material may have a thickness of at most 100 μm.

[0037] Thus, the white colored walls come into contact with the light sources to completely surround them. These walls make it possible, on the one hand, to intercept light emitted by the light source and which would be likely to reach another light source of the light module. Due to their white color, this light is reflected in the enclosure defined by the first walls and in which the light source is located.

[0038] These walls therefore significantly reduce the effects of interference or cross-talk and increase the efficiency of the light module. It is therefore possible to reduce the dimensions of the light sources to reduce the albedo of the light source. In addition, the edges, or thicknesses, of these white walls contribute to the visible, off appearance of the light module and therefore reduce the influence of the color of the photoluminescent element on this off appearance.

[0039] In another embodiment, the first opaque material is a dark-colored material, in particular black or gray.

[0040] Such a color of the first opaque material makes it possible to improve the extinguished appearance of the luminous device.

[0041] In another embodiment, and in order to improve the extinguished appearance of the luminous device, the first opaque material is a colored material.

[0042] Without departing from the scope of the invention, it can be imagined that the first opaque material comprises at least two different colors.

[0043] In a preferred embodiment of the invention, each first wall comprises at least one second groove filled with at least one second opaque material, of a color distinct from the first opaque material, forming a second wall.

[0044] In a particular embodiment, the second grooves of the first wall comprise dimensions ranging from 200 to 500 micrometers in width and a thickness of less than 1 millimeter, or even 0.2 millimeter.

[0045] In order to allow optimal filling of the second opaque material up to the bottom of the second furrows, a ratio of 1 is applied at least between the width of the furrow and its depth.

[0046] Thus, the lateral surfaces of each second wall are in contact with the material of the first wall.

[0047] Advantageously, all of the second grooves of all of the first walls are arranged so that all of the second walls formed by the second opaque material filling said second grooves form a grid, each light source of said plurality of light sources being arranged in a cell of this grid.

[0048] Thus, the fact that all of the light sources are arranged in cells of this grid makes it possible to create an enclosure in which the light emitted by said light sources is reflected in order to reduce the cross-talk phenomenon.

[0049] According to the invention, each second groove of the first wall extends into the layer of transparent material so that the second wall formed by the second opaque material filling said second groove extends substantially to the common support.

[0050] Advantageously, the layer of transparent material extends above the upper surfaces of the light sources and in which each second wall formed by the second opaque material filling each second groove extends substantially to the upper surface of said layer of transparent material.

[0051] Advantageously, the second opaque material is dark in color.

[0052] This layer of dark-colored material thus extends between two neighboring light sources, coming into contact with the external lateral surfaces of the white walls. Given its opacity and its color, it thus makes it possible to further limit the effects of interference or cross-talk which could remain, despite the presence of the white walls, to improve the extinguished appearance of the light module and to reduce its albedo.

[0053] Advantageously, the dark-colored material may be black or gray and have a mass transmission coefficient of between 50% and 95% over a thickness of 1 millimeter. It may, for example, be a polymer, in particular a resin from the epoxy or silicone family, enriched with carbon particles or black pigments. For example, it may be possible to envisage the concentration of carbon particles, namely the mass of carbon relative to the mass of the polymer, being less than 0.05%. This characteristic is particularly suitable when the light module is intended to perform a regulatory signaling function. Otherwise, it may be possible to envisage the concentration of carbon particles being greater than 0.05%, in particular in order to improve the contrast and the off-light appearance of the screen.

[0054] Advantageously, the light module comprises an additional diffusing layer extending above the layer of transparent material.

[0055] In a particular embodiment, the additional diffusing layer comprises a thickness substantially less than the thickness of the layer of transparent material.

[0056] Advantageously, the additional diffusing layer comprises a height of between 50 and 400 micrometers, preferably less than 200 micrometers.

[0057] Preferably, the additional diffusing layer is made of a diffusing material and / or comprising diffusing optical structures, which can be, for example, glued to the layer of transparent material or even be in one piece with the layer of transparent material.

[0058] Thus, in another embodiment, the layer of transparent material comprises, for example, at its upper surface a plurality of diffusing optical structures.

[0059] In a particular embodiment, the additional diffusing layer diffuses the light in a direction substantially perpendicular to the layer of transparent material.

[0060] In another embodiment, the additional diffusing layer diffuses the light in a predetermined direction in order to be able to correct the direction of diffusion of the light from the light module.

[0061] In a preferred embodiment, each of the light sources comprises at least one light-emitting semiconductor chip whose dimensions are between 50 micrometers and 1 millimeter, preferably between 100 micrometers and 400 micrometers.

[0062] Such a chip is known in particular as a miniLED. Where appropriate, the light sources can be arranged on the same common support so as to be spaced apart from each other by a distance of less than 1 millimeter.

[0063] In a particular embodiment, each of the light sources comprises at least one light-emitting semiconductor chip whose dimensions are between 5 micrometers and 30 micrometers.

[0064] Such a chip is known in particular as a microLED. Where appropriate, the light sources may be arranged on the same common support so as to be separated from each other by a distance of between 200 and 400 pm, or even less than or equal to 100 pm.

[0065] The term "dimensions" means the length of the light-emitting semiconductor chip whose length is the largest dimension of a rectangle.

[0066] Preferably, the light module comprises a connector for receiving an ins control instruction of said plurality of light sources and at least one controller capable of selectively controlling light sources, wherein the plurality of light sources forms a passive matrix and wherein the controller is arranged to control said passive matrix according to the control instruction received by the connector.

[0067] Advantageously, the light module comprises a connector for receiving a control instruction from said plurality of light sources and at least one controller capable of selectively controlling light sources. Where appropriate, the plurality of light sources forms a passive matrix and the controller is arranged to control said passive matrix as a function of the control instruction received by the connector. For example, the light module may comprise a plurality of devices for controlling the electrical power supplied to the light sources, each control device being mounted on a first face of the printed circuit board, in line with a light source, to control the electrical power supplied to the light source, in particular as a function of an instruction received from the controller intended for it.

[0068] Advantageously, the light module comprises at least 500 light sources, in particular distributed in a matrix manner, the controller being arranged to selectively control each of these light sources.

[0069] Advantageously, the light module comprises an interconnection system connected to the controller and arranged to interconnect the controller to the plurality of light sources. The interconnection system may be integrated into the printed circuit board or be an independent element mounted on this printed circuit board. The interconnection system may comprise a matrix of connectors, such as a ball matrix, also called BGA (from the English "ball grid array") or a matrix of pads, also called LGA (from the English "land grid array"), or a component with pins suitable for surface mounting.

[0070] The plurality of light sources forms a passive matrix where each row and each column of light sources is associated with a control device mounted on the PCB at the right of this row or this column to control the electrical power supplied to the light sources of this row or this column. The controller is thus arranged to control each of the sources of said passive matrix according to the control instruction received by the connector, by successively scanning the rows then the columns of the matrix to control the electrical power supplied to each of the light sources.

[0071] The invention also relates to a signaling device for a motor vehicle, characterized in that it comprises a light module according to the invention, said plurality of light sources forming a light screen of said signaling device. signaling.

[0072] The invention also relates to a method of manufacturing a light source according to the invention, the method comprising the following steps:

[0073] Assembly of a plurality of light sources on the same common support;

[0074] Depositing a layer of transparent material on the common support to encapsulate said plurality of light sources;

[0075] Cutting said layer of transparent material to form a plurality of first grooves, each first groove extending between two neighboring light sources;

[0076] Filling each first groove with a first opaque material to form first walls, each first wall separating two neighboring light sources.

[0077] Preferably, the step of depositing a layer of transparent material on the common support to encapsulate said plurality of light sources is carried out by deposition by molding, in particular by compression molding of the different opaque and transparent materials.

[0078] In a particular embodiment, the manufacturing method comprises the following additional steps:

[0079] Cutting each first wall to form a second groove in said wall;

[0080] Filling each second groove formed in each first wall with a second opaque material of a color distinct from the first opaque material, to form a second wall extending into said first wall.

[0081] Preferably, the manufacturing method also comprises a step of polishing the upper surfaces of the layer of transparent material, the first walls and, where appropriate, the second walls.

[0082] In a particular embodiment, the manufacturing method comprises a step of depositing an additional diffusing layer on the upper surfaces of the layer of transparent material, of the first walls and, where appropriate, of the second walls.

[0083] In a preferred embodiment, the additional diffusing layer is a diffusing film bonded to the upper surfaces of the transparent material layer.

[0084] In another embodiment, the method comprises a step of depositing a second layer of transparent material, followed by a step of abrading the upper surface of the second layer of transparent material.

[0085] In yet another embodiment, the layer of transparent materials directly undergoes a step of abrasion of its upper surface.

[0086] The present invention is now described using examples which are solely illustrative and in no way limitative of the scope of the invention, and from the drawings attached, drawings on which the different figures represent:

[0087] [Fig.l] represents, schematically and partially, a front view of a light module according to an embodiment of the invention;

[0088] [Fig.2] represents, schematically and partially, a sectional view of the module luminous of [Fig.l];

[0089] [Fig.3] represents, schematically and partially, a sectional view of a light module according to a particular embodiment;

[0090] In the following description, elements that are identical, by structure or by function, appearing in different figures retain, unless otherwise specified, the same references.

[0091] [Fig.l] describes a front view of a light module 1 according to an embodiment of the invention. In the example described, this light module 1 is intended to be integrated into a front or rear light of a motor vehicle, the light module 1 forming a screen. [Fig.2] describes a sectional view of this light module 1.

[0092] The light module 1 comprises a plurality of light sources 2 mounted on the same common support 3 formed in the example described by a printed circuit board.

[0093] In the example described, the light module 1 comprises more than 20,000 light sources 2, arranged so as to create a passive matrix, on 256 columns and 80 rows. The light sources 2 are mini-LEDs, the dimensions of which are between 100 pm and 400 pm. The light sources 2 are separated from each other by a distance less than or equal to 1 millimeter. It should be noted that other dimensions of the light sources 2, other distances between the light sources 2, other numbers of light sources 2 or even other distributions of the light sources 2 could be envisaged, without departing from the scope of the present invention.

[0094] All of the light sources 2 are mounted on the same common support 3 and are encapsulated on this support 3 in a layer of transparent material 4, and said layer of transparent material 4 comprises, between each pair of neighboring light sources 2, a first groove 5 filled with at least a first opaque material 51 forming a first wall 52 separating the light sources 2 of said pair.

[0095] The printed circuit board, or PCB, has a first face and a second face opposite the first face. The light sources 2 are mounted on the first face of the PCB, which faces the outside of the signaling device in which the light module 1 is integrated.

[0096] It should be noted that, in the example described, the printed circuit board is a so-called multi-layer PCB, comprising a stack of layers, between the first and second faces. These layers are in particular intended for the interconnection of the components mounted on the PCB, and may each comprise a plurality of through-vias, blind or buried, arranged in the PCB to be connected to the different interconnection layers. These vias open onto the first or second side of the PCB at the level of metal pads to which they are connected.

[0097] Advantageously, the light module 1 comprises a connector (not shown) for receiving a control instruction from said plurality of light sources 2 and at least one controller 9 capable of selectively controlling light sources 2. Where appropriate, the plurality of light sources 2 forms a passive matrix and the controller 9 is arranged to control said passive matrix as a function of the control instruction received by the connector. For example, the light module 1 may comprise a plurality of devices for controlling the electrical power supplied to the light sources 2, each control device being mounted on a first face of the printed circuit board, in line with a light source, to control the electrical power supplied to the light source, in particular as a function of an instruction received from the controller 9 intended for it.

[0098] It could be envisaged that a single controller 9 controls all of the light sources 2 mounted on the PCB or that a plurality of controllers 9 are provided, each selectively controlling a matrix, for example 64x64, or 4096, light sources 2.

[0099] The instruction may, for example, be an instruction issued by a computer of the motor vehicle or the signaling device for the display of a logo, a message, a pattern or a pictogram.

[0100] Again by way of example, it could be an instruction to display a pictogram intended to inform an outside observer of the opening of a door of the motor vehicle, a pictogram intended to inform a motorist following the motor vehicle of the presence of black ice on the road or even information relating to motor traffic.

[0101] The plurality of light sources 2 therefore forms a passive matrix where each row and each column of light sources 2 are associated with a control device (not shown) mounted on the PCB at the right of this row or this column to control the electrical power supplied to the light sources 2 of this row or this column. The controller 9 is thus arranged to control each of the sources of said passive matrix according to the control instruction received by the connector, by successively scanning the rows then the columns of the matrix to control the electrical power supplied to each of the light sources 2.

[0102] In the example described, the controller 9 is mounted on the second face of the PCB and is electrically interconnected to the metal pads provided on this second face. This interconnection can be achieved for example via a matrix of connectors (not shown, such as a matrix of balls, also called BGA (from the English "bail grid array").

[0103] Each light source 2 comprises a light-emitting semiconductor chip 21, forming an elementary light generator. The semiconductor may, for example, be a gallium nitride, or GaN, capable of emitting, by electroluminescence and in response to an electric current passing through it, blue light rays, for example the spectrum of which has a peak centered on a wavelength between 410 nm and 480 nm.

[0104] All of the first grooves 5 of the layer of transparent material 4 are arranged so that all of the first walls 52 formed by the first opaque material 51, filling said first grooves 5 form a grid, each light source of said plurality of light sources 2 being arranged in a cell 6 of this grid.

[0105] The plurality of first walls 52 is made of an opaque material, white in color. The white material may be a dielectric material, having a reflection coefficient of between 60 and 99%, in particular equal to 90%, such as a silicone resin enriched with titanium dioxide (TiO2).

[0106] Each first groove 5 extends in the layer of transparent material 4 so that the first wall 52 formed by the first opaque material 51 of white color filling said first groove 5 extends substantially to the common support 3 and the layer of transparent material 4 extends above the upper surfaces of the light sources 2.

[0107] Thus, each first wall 52 formed by the first opaque material 51 filling each first groove 5 extends substantially to the upper surface of said layer of transparent material 4.

[0108] Each first wall 52, coming into contact with a lateral surface of the layer of transparent material 4, up to an upper surface of the layer of transparent material 4. The walls thus extend against the layer of transparent material 4 until they come flush with the upper surface of the layer of transparent material 4, thus defining an enclosure framing the light sources 2.

[0109] Given the white color of these first walls 52, light rays which would be emitted by the light sources 2 in the direction of another light source 2 are intercepted by these first walls 52 and reflected in the direction of the emitting light source 2, which thus makes it possible to avoid parasitic effects and to increase the efficiency of the light module 1. In addition, the thicknesses of these white walls contribute to the visible appearance of the light module 1 when switched off.

[0110] The set of first walls 52 comprises a second groove 7 filled with at least one second opaque material 71 of dark color, for example black or gray, having a transmission coefficient of between 50% and 95%, on a thickness traveled of 1 millimeter. It could for example be a polymer, in particular a silicone enriched with carbon particles, the concentration of carbon particles being less than 0.05%, the second grooves 7 filled with the second opaque material 71 of dark color form a second wall 72.

[0111] These second walls 72 thus extend between two neighboring light sources 2, coming into contact with the external lateral surfaces of the first white walls 52. Given its opacity and its color, the second walls 72 thus make it possible to further limit the interference effects, and participate in improving the extinguished appearance of the light module 1 and in reducing its albedo.

[0112] Furthermore, the light module 1 comprises an additional diffusing layer 8 extending above the layer of transparent material 4. This characteristic makes it possible to further improve the extinguished appearance of the light module 1 and to reduce its albedo.

[0113] By way of example, it may be provided that each first wall 52 has a width of at most 100 μm, and that the width of the second wall 72 is between 200 μm and 500 μm.

[0114] [Fig. 3] describes an embodiment in which the light module 1 is devoid of a second groove 7.

[0115] Thus, the light module 1 comprises a plurality of light sources 2 mounted on the same common support 3 formed by a printed circuit board.

[0116] All of the light sources 2 are mounted on the same common support 3 and are encapsulated on this support 3 in a layer of transparent material 4, and said layer of transparent material 4 comprises, between each pair of neighboring light sources 2, a first groove 5 filled with at least a first opaque material 51 forming a first wall 52 separating the light sources 2 of said pair.

[0117] The light module 1 comprises a connector (not shown) for receiving a control instruction from said plurality of light sources 2 and at least one controller 9 capable of selectively controlling light sources 2. Where appropriate, the plurality of light sources 2 forms a passive matrix and the controller 9 is arranged to control said passive matrix as a function of the control instruction received by the connector.

[0118] All of the first grooves 5 of the layer of transparent material 4 are arranged so that all of the first walls 52 formed by the first opaque material 51, filling said first grooves 5 form a grid, each light source of said plurality of light sources 2 being arranged in a cell 6 of this grid. The plurality of first walls 52 is made of an opaque material, white in color.

[0119] Each first groove 5 extends in the layer of transparent material 4 so that the first wall 52 formed by the first opaque material 51 of white color filling said first groove 5 extends substantially to the common support 3 and the layer of transparent material 4 extends above the upper surfaces of the light sources 2.

[0120] Thus, each first wall 52 formed by the first opaque material 51 filling each first groove 5 extends substantially to the upper surface of said layer of transparent material 4.

[0121] Each first wall 52, coming into contact with a lateral surface of the layer of transparent material 4, up to an upper surface of the layer of transparent material 4. The walls thus extend against the layer of transparent material 4 until they come flush with the upper surface of the layer of transparent material 4, thus defining an enclosure framing the light sources 2.

[0122] Given the white color of these first walls 52, light rays which would be emitted by the light sources 2 in the direction of another light source 2 are intercepted by these first walls 52 and reflected in the direction of the emitting light source 2, which thus makes it possible to avoid parasitic effects and to increase the efficiency of the light module 1.

[0123] An example of a method for manufacturing a light source 2 of a light module 1 according to the embodiment of [Fig.l] to [Fig.3] will now be described.

[0124] In a first step, a plurality of light sources 2 is assembled on the same common support 3. A layer of transparent material 4 is deposited on the common support 3 to encapsulate said plurality of light sources 2.

[0125] In a second step, the layer of transparent material 4 is cut to form a plurality of first grooves 5, each first groove 5 extending between two neighboring light sources 2 and said first grooves 5 are filled with a first opaque material 51 of white color to form first walls 52, each first wall 52 separating two neighboring light sources 2.

[0126] Then, optionally, the first walls 52 are cut to form a second groove 7 in said first walls 52 in order to be filled with a second opaque material 71, of a color distinct from the first opaque material 51, namely a dark-colored material, to form a second wall 72 extending into said first wall 52.

[0127] Then, the upper surfaces of the layer of transparent material 4, of the first 52 and second walls 72 are polished.

[0128] Finally, the method ends with the deposition of an additional diffusing layer 8 on the upper surfaces of the layer of transparent material 4, on the first walls 52 and the second walls 72.

[0129] The preceding description clearly explains how the invention makes it possible to achieve the objectives it has set itself, namely to propose a light module capable of forming a screen having a good resolution, without a "cross-talk" effect, and a homogeneous lit appearance, without a "dotty effect", and which can be assembled without generating a defect despite the reduction in the dimensions of the light sources and the pitch separating two neighboring light sources.

[0130] It is thus understood that these objectives are achieved in particular by forming, directly on the support of the light sources or on a substrate extending over this support, a first wall separating the light sources, so as to form an opaque grid defining cells each containing a light source and each allowing the interception of light rays likely to interfere with a pixel formed by a neighboring light source. This grid can thus limit the “cross-talk” effect and therefore makes it possible to reduce the dimensions of the light sources as well as the pitch separating two neighboring light sources, while using an element to diffuse the light emitted by each light source, in order to avoid a “dotty effect”.In addition, since the grid is produced by overmolding, it is thus freed from the constraints of positioning the grid in relation to the matrix of light sources during assembly, which could be generated by a variation in the dimensions of the grid due to manufacturing tolerances or a phenomenon of thermal expansion.

[0131] In any event, the invention cannot be limited to the embodiments specifically described in this document, and extends in particular to any equivalent means and to any technically effective combination of these means. In particular, it may be possible to replace the printed circuit board with another support, such as a ceramic or glass substrate, rigid or flexible, straight or curved. It may also be possible to provide for the light sources to form an active matrix. It may also be possible to provide other types of light sources than those described, and in particular light sources of smaller dimensions, for example between 5 pm and 150 pm, such as micro-LEDs.It will also be possible to consider materials other than those described, or to exchange the different materials of the embodiments which have been described, in particular to produce walls of grey, white or black color, or even to produce alternations or variations in the color of the walls in the same embodiment.

Claims

Claims

1. Light module (1) of a signaling device of a motor vehicle, comprising a plurality of selectively controllable light sources (2), characterized in that all of the light sources (2) are mounted on the same common support (3) and are encapsulated on this support in a layer of transparent material (4), and in that said layer of transparent material (4) comprises, between each pair of neighboring light sources (2), a first groove (5) filled with at least a first opaque material (51) forming a first wall (52) separating the light sources (2) of said pair.

2. Light module (1) according to the preceding claim, characterized in that all of the first grooves (5) of the layer of transparent material (4) are arranged so that all of the first walls (52), formed by the first opaque material (51) filling said first grooves (5), form a grid, each light source (2) of said plurality of light sources (2) being arranged in a cell (6) of this grid.

3. Light module (1) according to one of the preceding claims, characterized in that each first groove (5) extends in the layer of transparent material (4) so ​​that the first wall (52) formed by the first opaque material (51) filling said first groove (5) extends substantially to the common support (3).

4. Light module (1) according to the preceding claim, characterized in that the layer of transparent material (4) extends above the upper surfaces of the light sources (2) and in which each first wall (52) formed by the first opaque material (51) filling each first groove (5) extends substantially to the upper surface of said layer of transparent material (4).

5. Light module (1) according to one of the preceding claims, characterized in that the first opaque material (51) is a white-colored material.

6. Light module (1) according to one of claims 1 to 4, characterized in that the first opaque material (51) is a dark-colored material.

7. Light module (1) according to one of the preceding claims, characterized in that each first wall (52) comprises at least one second groove (7) filled with at least one second opaque material (71), of a color distinct from the first opaque material (51), forming a second wall (72).

8. Light module (1) according to the preceding claim, characterized in that the second opaque material (71) is dark in color.

9. Light module (1) according to one of the preceding claims, characterized in that it comprises an additional diffusing layer (8) extending above the layer of transparent material (4).

10. Light module (1) according to one of claims 1 to 8, characterized in that each of the light sources (2) comprises at least one light-emitting semiconductor chip (21) whose dimensions are between 50 micrometers and 1 millimeter, preferably between 100 micrometers and 400 micrometers.

11. Light module (1) according to one of the preceding claims, characterized in that each of the light sources (2) comprises at least one light-emitting semiconductor chip (21) whose dimensions are between 5 qm and 30 qm.

12. Light module (1) according to one of the preceding claims, characterized in that it comprises a connector for receiving a control instruction from said plurality of light sources (2) and at least one controller (9) capable of selectively controlling light sources (2), in which the plurality of light sources (2) forms a passive matrix and in which the controller (9) is arranged to control said passive matrix as a function of the control instruction received by the connector.

13. A method of manufacturing a light source of a light module (1) according to one of the preceding claims, characterized in that it comprises the following steps: a. Assembling a plurality of light sources (2) on a common support (3); b. Depositing a layer of transparent material (4) on the common support (3) to encapsulate said plurality of light sources (2); c. Cutting said layer of transparent material (4) to form a plurality of first grooves (5), each first groove (5) extending between two neighboring light sources (2); d. Filling each first groove (5) with a first opaque material (51) to form first walls (52), each first wall (52) separating two neighboring light sources (2).

14. Method according to the preceding claim, characterized in that it comprises the following steps: a. Cutting each first wall (52) to form at least one second groove (7) in said wall; b. Filling each second groove (7) formed in each first wall (52) with a second opaque material (71) of a color distinct from the first opaque material (51), to form a second wall (72) extending into said first wall (52).

15. Method according to one of claims 12 or 13, characterized in that it comprises a step of polishing the upper surfaces of the layer of transparent material (4), the first walls (52) and, where appropriate, the second walls (72).

16. Method according to one of claims 12 to 14, characterized in that it comprises a step of depositing an additional diffusing layer (8) on the upper surfaces of the layer of transparent material (4), of the first walls (52) and, where appropriate, of the second walls (72).

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