FR3061537A1 - LUMINOUS EMISSION MODULE WITH IMPROVED GUIDE RAIL - Google Patents

Abstract

The guide ply has an inlet portion (16) arranged at one end of the guide ply, said end extending along a path (T), the inlet portion having a coupling profile adapted to optically coupling the input portion to the light emission source for the penetration of at least a portion of the light rays from the source into the guide sheet, the coupling profile extending over at least part of the path (T), the guide web further comprising a guide portion (18) optically coupled to the input portion and adapted to guide therein at least a portion of the light rays coming from the input portion and for forming a light beam from said light rays coming from the input portion.

Description

Holder (s): folded.

VALEO VISION Joint-stock company simO Extension request (s):

Agent (s):

VALEO VISION Limited company.

* 54) LIGHT EMISSION MODULE WITH IMPROVED GUIDANCE TABLE.

FR 3,061,537 - A1 (57) The guide ply has an inlet portion (16) arranged at one end of the guide ply, said end extending along a path (T), the portion d input comprising a coupling profile suitable for optically coupling the input portion to the light emission source for the penetration of at least a portion of the light rays coming from the source into the guide ply, the coupling profile s 'extending over at least part of the path (T), the guide sheet further comprising a guide portion (18) optically coupled to the inlet portion and adapted to guide within it at least part of the light rays itself arriving from the inlet portion and to form a light beam from said light rays reaching it from the inlet portion.

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Light emission module with improved guide ply

The invention relates to the field of light emission modules, in particular for a motor vehicle.

In terms of light emission, in particular in the automotive field, light emission devices are used in particular to perform various lighting and signaling functions.

One category of these devices is based on the use of a light guide, which is an optical part capable of guiding light by total internal reflection of this light, for example from an entry area to an exit area. of the guide. The guide is in the form of a guide ply having a general plate configuration. The sheet is intended to be optically coupled to a light emission source for the injection of light rays into the guide and their guidance within the guide in the direction of at least one exit face of the latter.

The configurations currently used for this type of light emission system components have drawbacks, however.

Indeed, it is difficult to obtain a homogeneous luminous rendering, in particular for guides having large dimensions. This homogeneity can be increased, but generally involves the multiplication of the light sources coupled to the guide ply, which is not acceptable. Indeed, on the one hand, the use of a multitude of sources entails significant costs, on the other hand, a minimum residual space between two sources must be respected to ensure the electrical connections but also taking into account the size of the boxes that encapsulate the sources.

In addition, the optical coupling of the light emission source to the guide sheet is generally a source of substantial losses.

The invention improves the situation.

To this end, the invention relates to a guide sheet adapted to guide light rays coming from a light emission source intended to be optically coupled to said guide sheet, the guide sheet having an inlet portion arranged at one end of the guide ply, said end extending along a path, the inlet portion comprising a coupling profile adapted to optically couple the inlet portion to the light emission source for the penetration of '' at least part of the light rays coming from the source in the guide ply, the coupling profile extending over at least part of the path, the guide ply further comprising a guide portion optically coupled to the portion d entry and adapted to guide within it at least part of the light rays reaching it from the entry portion and to form a light beam from said light rays x reaching him from the entrance portion.

According to one aspect of the invention, the coupling profile defines a cavity for the optical coupling of the light emission source with the input portion, the coupling profile comprising a first portion configured to deflect at least part of the rays luminaries reaching it from the light emission source by refraction, and at least a second portion configured to deflect at least part of the light rays by reflection, the first and second portions delimiting the cavity.

According to one aspect of the invention, the first portion has a wall delimiting the cavity, the wall having a curved shape whose concavity is oriented away from the cavity.

According to one aspect of the invention, the second portion comprises a first wall adapted for the penetration into the guide ply of at least a portion of the light rays coming from the light emission source, and a second wall adapted to deviate from the minus part of the light rays reaching it from the first wall by total internal reflection.

According to one aspect of the invention, the guide portion comprises an outlet portion having at least one outlet face for the exit of the light rays from the guide sheet.

According to one aspect of the invention, the guide portion comprises deflection elements configured to deflect a part of the light rays reaching said deflection elements towards the exit face.

According to one aspect of the invention, the deflection elements are arranged within the guide portion so that the luminance provided by the outlet face is substantially uniform.

According to one aspect of the invention, the inlet portion and the coupling profile extend over substantially the entire path.

According to one aspect of the invention, the path is curved.

According to one aspect of the invention, the path is straight.

According to one aspect of the invention, the guide portion does not extend along a plane.

According to one aspect of the invention, the ratio between a dimension of the entry portion along the path and a height of the cavity is greater than or equal to 5.

The invention further relates to a light emission module, comprising a guide ply as defined above and a light emission source arranged opposite the coupling profile.

According to one aspect of the invention, the light emission source has a generally linear shape.

According to one aspect of the invention, the light emission source extends over substantially the entire length of the coupling profile along the path.

According to one aspect of the invention, the light emission source has a light emission zone having a height transverse to the path, the ratio between the dimension of the inlet portion along the path and the height of the zone d light emission being greater than or equal to 30.

The invention further relates to a light emission device, in particular for a motor vehicle, comprising a light emission module as defined above.

The invention will be better understood on reading the detailed description which follows, given solely by way of example and made with reference to the appended Figures, in which:

- Figure 1 is a schematic illustration of a light emitting device according to the invention;

- Figure 2 illustrates a guide sheet of a light emission module according to the invention;

- Figure 3 illustrates a longitudinal sectional view of the guide ply of Figure 2;

- Figure 4 illustrates a front view of a light emission source intended to be coupled to a guide ply according to the invention; and

- Figure 5 schematically illustrates a top view of a light emission source according to a particular embodiment.

Figure 1 illustrates a light emitting device 2 according to the invention, hereinafter device 2, configured to emit light.

The device 2 is advantageously a device intended to be integrated into a motor vehicle. In other words, it is a motor vehicle device.

Advantageously, the device 2 is a lighting and / or signaling device for a motor vehicle.

It is for example configured to implement one or more photometric functions.

A photometric function is for example a lighting and / or signaling function visible to a human eye. It is noted that these photometric functions can be the subject of one or more regulations establishing requirements for colorimetry, intensity, spatial distribution according to a so-called photometric grid, or even ranges of visibility of the light emitted.

The device 2 is for example a lighting device and then constitutes a vehicle headlight - or headlight - intended to be arranged at the front of the vehicle. It is then configured to implement one or more photometric functions, for example chosen from a low beam function called "code function", a high beam function called "road function", an anti-fog function.

Alternatively or in parallel, the device is a signaling device intended to be arranged at the front or at the rear of the vehicle.

When it is intended to be arranged at the front, the photometric functions that it is configured to implement (possibly in addition to that (s) that it implements as a lighting device) include a direction change indication function, a daytime running light function known by the acronym DRL, for "Daytime Running Light", a front light signature function, a position light function, a so-called "Side function -marker ", which comes from English and can be translated by side signage.

When it is intended to be arranged at the rear, these photometric functions include a reversing indication function, a stop function, a fog function, a direction change indication function, a rear light signature function, a lantern function, a “Side-marker” function.

Alternatively, the device 2 is provided for lighting the passenger compartment of a vehicle and is then intended to emit light mainly in the passenger compartment of the vehicle.

In what follows, the device 2 is described in a nonlimiting manner in a configuration in which it is intended to emit light outside the vehicle.

Referring to Ligure 1, the device 2 comprises a housing 4 and a closing glass 6 cooperating with each other to internally delimit a cavity 8.

The device 2 further comprises a light emission module 10 according to the invention, hereinafter module 10, arranged in whole or in part in the cavity 8.

The module 10 is configured to emit a light beam E. For example, in the example of Ligure 1, it is arranged to emit the light beam E towards the closing glass (which is transparent for at least part of the light beam emitted by module 10).

Referring to Figure 2, the module 10 includes a guide sheet 12 and at least one light emission source 14 adapted to emit light rays.

The guide ply 12 is configured to guide at least part of the light rays emitted by the source 14 and emit at least part of these light rays to form the light beam F, for example by decoupling the light rays, as described below. after.

The guide ply is a light guide whose thickness is small compared to its length and its width. It can be curved and have a given curve. The tablecloth has two extended faces (its lower and upper faces in Figure 2) separated by a periphery, or edge. This periphery defines a thickness of the sheet, which can be variable, for example decreasing from one longitudinal end to the other. These extended faces form guide faces delimiting a zone of propagation of the light rays, by internal reflection on these faces.

The guide ply 12 is intended to be optically coupled to the light emission source 14 so that at least some of the light rays emitted by the source 14 penetrate into the guide ply 12.

The guide ply 12 is for example made from polymethyl methacrylate (PMMA), polycarbonate (acronym PC), or glass. In practice, any material exhibiting good transparency in the visible range can be used.

The guide ply 12 includes an inlet portion 16 and a guide portion 18 optically coupled to each other.

The inlet portion 16 is suitable for the penetration of light rays from the light emission source 14 into the guide ply 12, and to allow their penetration into the guide portion 18. In addition, it is configured so that the light rays which penetrate into the guide portion penetrate therein with an angle allowing the total internal reflection of the light rays penetrating into the guide sheet in the guide portion.

The inlet portion 16 is located at one end of the ply 12, such as a longitudinal end. For example, as illustrated in Figure 2, it is formed in the corresponding edge of the sheet.

This end of the sheet extends along a path, or direction, T. The inlet portion 16 extends along at least part of the path T. Advantageously, it extends over substantially the entire path T

This path defines the direction in which the entrance portion extends. The path T goes from one end of the longitudinal end here of the ply (for example located at a side edge of the ply 12) to the other (for example also located at the opposite side edge).

In the context of the invention, the path T is arbitrary. More specifically, the route is not necessarily straight or even plan.

For example, the path is curved and / or is not contained in a plane.

However, configurations with a straight path are also envisaged, as are planar configurations. In the example in Figure 2, the path T is straight and planar. In the example in Figure 5, the path is flat and curved.

The dimension 1 of the inlet portion 16 along the path T is large in front of at least one dimension of the inlet portion 16 transverse to the path. Advantageously, this dimension is large compared to the height h of the inlet portion 16 in the sense of the orientation of Figures 2 and 3.

Advantageously, the ratio between the length 1 and the height h of the inlet portion 16 is greater than 5.

Advantageously, the inlet portion 16 has a length 1 along the path greater than 30 mm. For example, this length is several centimeters.

The height h of the inlet portion 16 is for example less than 10 mm, and is advantageously between 1 mm and 8 mm. For example, this height is approximately 4 mm.

The input portion has a coupling profile which is specifically provided for the optical coupling of the input portion and therefore of the guide ply, with the source 14. This coupling profile advantageously extends along the entire entry portion, and therefore advantageously substantially along the entire path T.

By way of example, here, by substantially the entirety, we mean that it extends over a distance greater than 90%, even 95% of the length of the path T.

Referring to Figure 3, advantageously, the coupling profile defines a cavity 20 for the facing of the source 14 and the guide ply 12 and their optical coupling.

The description which is given below is here in a nonlimiting manner for such a configuration.

This cavity 20 extends over part of the thickness of the guide ply 12, that is to say over part of the height of the ply 12 and over part of its length. The cavity is for example open to the outside.

The cavity has a height advantageously between 500 μm and 5 mm. This height corresponds for example to the vertical dimension of the cavity at its mouth (in the sense of the orientation of Figure 3).

The ratio of the length l_ ^e tl ^{to the} height of the cavity is advantageously greater than 5. For example, it is between 5 and 10.

The cavity 20 extends over at least part of the path T. Advantageously, it extends over substantially the whole of this path, as illustrated in FIG. 2.

The coupling portion, which advantageously corresponds to the inlet portion itself and the cross section of which is illustrated in FIG. 3, comprises a first portion 22 and at least a second portion 24.

These portions 22 and 24 extend over the entire length of the cavity along the path T and delimit the latter.

The first portion 22 is adapted to deflect at least a portion of the light rays reaching it from the source 14 by refraction. The rays from the source 14 and deflected by the central portion 22 form first rays RI (only one is shown in Figure 3).

The first portion 22 is adjacent to the cavity, and is intended to be arranged opposite the source 14 for their optical coupling.

The first portion 22 has a wall defining the cavity. This wall has a curved shape, the concavity of which is turned away from the cavity. In other words, the convexity of the wall is turned towards the source.

Advantageously, the first portion 22 is located approximately half the thickness of the ply 12.

Advantageously, the section of the first portion transverse to the path T has an axis of symmetry. This axis is for example substantially orthogonal to a substrate of the light emission source described below and which is opposite the first portion. This axis is horizontal in Figure 3.

Advantageously, the first portion 22 is configured so that the first rays RI form a small angle with at least one large face of the guide portion, at least in a region thereof adjacent to the inlet portion. In other words, the first portion 22 is configured to increase the collimation of the rays from the light emission source 14 which reach it and which are deflected by it.

This makes it possible to obtain configurations of propagation of the RI rays allowing total internal reflections at the level of these faces.

In practice, this property is obtained by giving the first portion, and more specifically to its wall delimiting the cavity which forms a diopter with the middle of the cavity, an adapted shape. This form is for example known to a person skilled in the art.

For example, due to the collimation induced by the first portion, the average of the angles formed between the directions of propagation of the rays RI at their entry into the guide portion and at least a portion of a large face of the guide ply near the entrance portion is substantially zero.

Still with reference to FIG. 3, the second portion 24 is configured to deflect at least part of the light rays which reach it from the source 14 at least by reflection. Advantageously, it is configured to do this at least by total internal reflection.

This second portion 24 is adjacent to the first portion 22 and to the cavity.

The second portion 24 comprises a first wall 26 adjacent to the cavity and suitable for the penetration into the guide ply 12 of at least part of the light rays coming from the light emission source 14.

This first wall 26 delimits the cavity 20 together with the wall of the central portion 22. This first wall 26 extends for example from one end of the wall of the first portion delimiting the cavity to a rear end of the cavity 20 .

This first wall 26 is for example planar. Alternatively, it has any shape.

This wall 24 is adapted so as not to deflect the light rays coming from the source 14 and passing through it. Alternatively, it is configured to deflect by refraction. Alternatively still, it comprises a sub-portion adapted so as not to deflect the light rays which pass through it, and a second sub-portion adapted to, conversely, deflect them by refraction.

The second portion 24 further includes a second wall 28 arranged to receive at least a portion of the light rays passed through the first wall 24. This second wall 28 is adapted to deflect at least a portion of the light rays reaching it by reflection. More specifically, this second wall 28 is adapted to deflect a part of the light rays reaching it by total internal reflection.

This second wall 28 extends from the end of the first wall 26 located at the rear of the cavity 20 to the guide portion 18 (the demarcation between the inlet portion 16 and the guide portion 18 is symbolized by a vertical dotted line in Figure 3).

This wall has for example a curved shape, such as for example convex, the convexity being turned towards the outside. The precise shape of this wall is easily determined by a person skilled in the art.

The light rays coming from the source 14 then deflected by the second portion 24 form second light rays R2 (two are shown in Figure 3).

Advantageously, the second portion 24 is configured so that the second rays R2 form a small angle with at least one large face of the guide ply, at least in a region of the latter adjacent to the inlet portion In other words, it is configured to increase the collimation of the light rays coming from the source 14 and which reach it.

This makes it possible to obtain configurations of propagation of the R2 rays allowing total internal reflections at the level of these faces.

For example, due to the collimation induced by the second portion, the average of the angles formed between the directions of propagation of the rays R2 at their entry into the guide portion and at least a portion of a large face of the guide ply near the entrance portion is substantially zero.

.In practice, this property results from the combined shapes and relative arrangements of the first and second walls, which are then chosen in an appropriate manner. As before, these forms and arrangements are easily determined by a person skilled in the art.

In the description given above, the inlet portion 16 has been described as comprising a second portion 24. Advantageously, it comprises two such second portions. As illustrated in FIG. 3, these portions are located on either side of the first portion 22. In the sense of the orientation of FIG. 3, they are therefore located below the first portion for one, and above for the other.

Ees two second portions 24 present are for example symmetrical with respect to each other relative to a plane.

However, alternatively, they have respective non-symmetrical configurations. For example, the first walls 26 have different respective configurations in terms of flatness and / or inclination relative to the first portion. Alternatively or in parallel, the respective shapes of the second walls 28 of the two second portions are different.

The guide portion 18 is configured to guide the light rays reaching it from the entry portion within it. It is further configured to form the output beam F.

To this end, and as indicated above, the guide portion 18 is optically coupled to the inlet portion 16.

Advantageously, these portions have come together from one another. In other words, they are adjacent, one being an extension of the other. They are preferably made from the same material.

The guide portion 18 is in the general form of a plate. In other words, it has a small thickness compared to its other dimensions. For example, its thickness corresponds to the height h of the entrance portion. This thickness is for example substantially constant over the entire guide portion. Alternatively, this thickness varies along the guide portion 18.

For example, the guide portion has a length L greater than 20 mm. For example, it is also less than 400 mm

In addition, its dimension along the path T, that is to say its width, advantageously corresponds to the length 1 of the inlet portion (along the path T) over at least part of the length L.

In some embodiments, the width of the guide portion varies along it.

In an embodiment such as that of Figures 2 and 3, the guide portion extends substantially along a plane. Alternatively, it does not extend according to a plan.

For example, it has a general broken line configuration, or a curved or wavy configuration.

With reference to FIGS. 2 and 3, the guide portion 18 has an upper face 30, a lower face 32 and free ends, or end faces, 34.

The top and bottom sides are facing each other. These surfaces are flat or not.

The free ends of the guide portion 18 are in the form of slices. These sections are advantageously configured so that the rays which reach them are totally reflected.

The sections are for example contained in respective plans. Alternatively, at least one of the franks is not contained in a plan. It has for example a generally curved, wavy or broken line shape.

The guide portion 18 further comprises an outlet portion 36 for the exit of the light rays from the guide sheet 12 and the formation of the beam F.

The outlet portion 36 comprises at least one outlet face 37 formed by at least part of one of the faces of the guide portion.

In a first configuration, the outlet portion 36 is made up of all or part of the section 34 of the guide portion which is opposite to the entry portion (this section is reference 34E in FIG. 3). In other words, the outlet portion 36 is limited to the edge of the guide ply which is opposite to the inlet portion 16.

In a second configuration such as that of FIGS. 1 to 3, the outlet portion 36 comprises at least part of a section of the guide portion other than the section opposite the inlet portion. For example, the outlet portion 36 then comprises several outlet faces, or else just one.

In this second configuration, the guide portion 18 comprises, in addition to the elements described above, deflection elements 38, or decoupling elements, configured to deflect, or decouple, at least part of the light rays guided in the guide portion towards the corresponding output face.

Preferably, the deflection elements are configured to deflect the rays reaching them by total internal reflection.

These deflection elements 38, sometimes called decoupling elements, are advantageously in the form of reliefs. These reliefs have for example a general serrated shape, of streaks or portions of the external surface of a torus. These reliefs are in the form of projections or depressions.

For each outlet face 37 other than the face of the guide portion 16 opposite to the inlet portion, the face opposite to this outlet face comprises deflection elements 38 formed therein. In other words, the deflection elements are formed in the face opposite to the outlet face considered.

In the example of FIG. 3, the upper face 30 is an outlet face 37, deflection elements being provided in the lower face 32 for deflecting part of the light rays from the guide in the direction of the upper face 30.

Advantageously, for at least one given outlet face 37, the associated deflection elements are arranged within the guide portion so that the luminance provided by the outlet face 37 is substantially uniform.

The resulting arrangement is variable depending on the configuration of the guide ply.

In practice, this property is conditioned - all other things being equal - by the size of the deflection elements, the efficiency of the deflection elements and / or the density of their distribution.

For example, the size of the deflection elements increases as one moves away from the source.

Alternatively or in parallel, the efficiency of the deflection elements increases the further we get from the source

Alternatively or in parallel, the concentration of the deflection elements increases when one moves away from the source (i.e. their number per unit area increases as one moves away from the source ).

For example, in a particular case, the deflection elements 37 considered are arranged in a matrix arrangement with two directions, including a direction substantially orthogonal to the path T.

For a row of deflection elements along this direction, the deflection elements have variable spacing along the path of this direction. For example, this spacing decreases as you move away from the entrance portion.

However, other arrangements are envisaged. For example, for at least one outlet face, the corresponding deflection elements are arranged in a regular matrix arrangement.

Note that in an advantageous embodiment, the guide portion comprises a single outlet face 37 other than the edge of the sheet opposite to the inlet portion (and which is therefore associated with elements 38).

With reference to Figures 4 and 5, the light emission source 14 is configured to emit light rays. Advantageously, it is semiconductor, that is to say that it comprises a semiconductor element suitable for emitting light rays.

The source 14 is arranged opposite the cavity 20, or else within the cavity 20 at least in part.

In the context of the invention, the source 14 has a general linear configuration extending along all or part of the path T. More specifically, it advantageously extends along substantially the entire coupling profile and the cavity 20.

For example, thus, it extends over a length greater than 90% of the dimension of the cavity along the path T, or even 95%.

It has a general shape corresponding to that of at least part of the path T, and advantageously of the entirety of this path T. In other words, it is arranged in the cavity (or around it) so that its shape follows that of the cavity along the path (or the corresponding portion of the path).

Referring to Figure 4, the source 14 is configured to emit light. Advantageously, it is semiconductor, that is to say that it comprises a semiconductor element adapted to emit light.

The source 14 advantageously comprises electroluminescent units 40 of submillimetric dimensions adapted to emit light when supplied with electrical energy, and a substrate 42 from which these units extend. Only a few units are shown in Figure 5.

Advantageously, the units are sticks.

The description which follows is given in a nonlimiting manner in this sense.

The substrate 42 forms a support for the rods 40. The substrate 42 is suitable for supplying electrical energy to the rods 40. For this purpose, it comprises one or more metallized tracks suitable for conveying electrical energy from a electric power source (not shown) to the sticks 40. This or these tracks are advantageously configured to connect all or part of the sticks together so as to define one or more subgroups of sticks 40, and to allow selective feeding of these subgroup (s). The control of the power supply of the sub-groups is advantageously carried out by means of a control module forming part of the module 10.

The substrate 42 is in the form of a flat plate.

The substrate is for example made from silicon or silicon carbide.

The substrate comprises an upper face in contact with which the rods 40 are arranged from which they extend. The rods 40 are for example arranged on a central zone of this face, which then optionally has edges not carrying a rod.

The rods 40 are configured to emit light. For example, the sticks 40 are configured to emit light of blue, red or green color.

The rods 40 are in the form of studs of small dimensions having one or more lateral faces and a free end opposite the substrate. This end is for example in the form of an end face. The rods are adapted to emit light from their side faces. Optionally, they also emit light from the end face.

The rods 40 extend projecting from the upper face of the substrate 42. The rods 40 extend for example substantially parallel to each other. For example, they extend perpendicular to the substrate.

Each rod has for example a generally cylindrical shape extending along a longitudinal axis. For example, they have a circular or polygonal section. Alternatively, they have a section of any shape.

The rods 40 are of submillimetric dimensions. In other words, their dimensions are less than a millimeter. In addition, they have a height greater than or equal to one micrometer. For example, this height is between 1 and 10 pm. For example, the rods have a diameter of about 1 µm. In addition, the spacing between the rods is between 3 pm and 10 pm.

Due to the presence of these rods 40, the source 14 is a three-dimensional semiconductor light source, as opposed to light sources composed of photoemissive elements of the light emitting diode type, which form substantially planar sources occur. in the form of a thin layer, their thickness being of the order of a few nanometers.

The rods 40 are for example made from gallium nitride (GaN), an alloy of aluminum nitride and gallium nitride (AlGaN), or from an alloy of aluminum, indium, gallium and / or phosphorus (AlInGaP).

For example, they are formed on the substrate 42 by epitaxial growth.

The rods 40 comprise a core, for example made of gallium nitride, around which are arranged quantum wells formed by a superposition of layers of different materials, for example gallium nitride and gallium-indium nitride. In addition, they include a shell surrounding the quantum wells, for example also made of gallium nitride. This shell is for example coated with a layer of transparent conductive oxide (OCT) which forms an anode of the rod complementary to the cathode formed by the substrate 42.

In the context of the invention, the substrate advantageously has a height less than the height of the cavity to allow its presence in the cavity or in its immediate surroundings.

In addition, the rods are arranged on the substrate so as to define at least one emission zone Z, for example covered with rods, having a height h _z less than or equal to 500 μm. This height is for example between 50 and 500 μm. Furthermore, the ratio between the length 1 of the inlet portion 16 along the path T and this height is advantageously greater than 30.

Advantageously, the length of the substrate corresponds substantially to the length of the cavity 20 of the inlet portion. In addition, zone Z extends substantially over the entire length of the substrate. This is particularly advantageous for obtaining good homogeneity for the device 2.

The source 14, and more specifically the rods 40, is arranged opposite the first portion 22 of the inlet portion 16.

In certain embodiments illustrated in FIG. 5, in particular those in which the path T is curved or non-planar, the source 14 is advantageously in the form of a plurality of sub-sources I4 |, ..., 14 _n each comprising a substrate and sticks as described above. The flat substrates each have a length strictly less than the length of the entry portion along the path. Each sub-source 14; is arranged opposite or in the cavity 18, the rods facing the first portion 22 of the inlet portion 16, the sources being arranged one after the other so as to provide a substantially continuous overall light source in the cavity along the way. In practice, with substantially each section of cavity along the path T is associated a sub-source 14; which is located opposite or in the considered section. The substrates of two consecutive sub-sources are then arranged in relation to each other to follow the path of the cavity along the path.

The operation of the light emission module 10 according to the invention will now be described with reference to the Figures.

Putting the light emission device 2 into operation results in the emission, by the light emission source 14, of light rays within the cavity 20 delimited by the first portion 22 and the first walls 26 of the second portions .

At least part of these light rays penetrates into the inlet portion 16 while being deflected by the first portion 22 by refraction. Another part enters it by the second portions 24, and is deflected by them. Once deflected by the entry portion, the resulting spokes pass through the guide portion 18, which is optically coupled to the entry portion.

They then propagate in the guide portion 18.

At least part of these rays then leaves the sheet 12 through the outlet face 36.

For this purpose, if necessary, these radii are deflected by the deflection elements towards the exit face 36. If not, they propagate in the guide ply up to the exit face, which they cross to exit the tablecloth.

The rays leaving the guide ply form the exit beam (which may have several sub-beams having different directions, in particular if the exit portion has different exit faces).

The invention has several advantages.

First of all, the configuration of the input portion of the guide ply makes it possible to obtain very good efficiency for orienting the light in a preferred direction, in particular when coupled to a source of substantially linear light emission. In addition, the guide ply is simple and robust, and is easily adapted to many configurations of use.

In the above description, the module 10 is shown as arranged inside a housing at least in part 10. As a variant, the device 2 has no housing. The guide ply is arranged within the vehicle in its configuration of use, for example by means of a frame.

In addition, optionally, the device 2 is also devoid of closing glass. The outlet face (s) 37 of the guide ply 12 are arranged so that the beam (s) F is oriented in the desired direction.

In addition, as suggested above, the guide ply may have a plurality of outlet faces respectively associated or not with deflection elements. However, in certain usage configurations, a single outlet face may be preferred.

Claims (17)

Claims: 1. Guide sheet adapted to guide light rays coming from a light emission source (14) intended to be optically coupled to said guide sheet (12), the guide sheet having an inlet portion (16) arranged at one end of the guide ply, said end extending along a path (T), the input portion comprising a coupling profile adapted to optically couple the input portion to the emission source light for the penetration of at least part of the light rays coming from the source into the guide ply, the coupling profile extending over at least part of the path (T), the guide ply further comprising a portion guide (18) optically coupled to the input portion and adapted to guide within it at least part of the light rays reaching it from the input portion and to form a light beam (F) from said light rays coming from the entrance portion. 2. Guide sheet according to claim 1, in which the coupling profile defines a cavity (20) for the optical coupling of the light emission source with the input portion, the coupling profile comprising a first portion (22 ) configured to deflect at least part of the light rays reaching it from the light emission source by refraction, and at least a second portion (24) configured to deflect at least part of the light rays by reflection, the first and second portions delimiting the cavity ,. 3. Guide sheet according to claim 2, wherein the first portion (22) has a wall delimiting the cavity, the wall having a curved shape whose concavity is oriented away from the cavity. 4. Guide sheet according to claim 2 or 3, wherein the second portion comprises a first wall (26) adapted for the penetration into the guide sheet of at least part of the light rays coming from the light emission source. , and a second wall (28) adapted to deflect at least part of the light rays reaching it from the first wall by total internal reflection. 5. Guide sheet according to any one of the preceding claims, in which the guide portion comprises an outlet portion (36) having at least one outlet face (37) for the exit of the light rays from the guide sheet. 6. Guide sheet according to claim 5, in which the guide portion comprises deflection elements (38) configured to deflect a part of the light rays reaching said deflection elements in the direction of the exit face. 7. Guide sheet according to claim 6 wherein the deflection elements are arranged within the guide portion so that the luminance provided by the outlet face (37) is substantially uniform. 8. Guide sheet according to any one of the preceding claims, in which the inlet portion and the coupling profile extend over substantially the entire path (T). 9. Guide sheet according to any one of the preceding claims, in which the path is curved. 10. Guide sheet according to any one of claims 1 to 8, in which the path is rectilinear. 11. Guide sheet according to any one of the preceding claims, in which the guide portion (18) does not extend in a plane. 12. Guide sheet according to claim 2, in which the ratio between a dimension of the inlet portion (12) along the path and a height of the cavity is greater than or equal to 5. 13. Light emission module, comprising a guide ply (12) according to any one of the preceding claims and a light emission source (14) arranged opposite the coupling profile. 14. Light emission module according to claim 13, wherein the light emission source has a generally linear shape. 15. Light emission module according to claim 14, wherein the light emission source extends over substantially the entire length of the coupling profile along the path (T). 16. Light emission module according to any one of claims 13 to 15, in which the light emission source has a light emission zone having a height transverse to the path, the ratio between the dimension of the portion of entry along the path and the height of the light emission zone being greater than or equal to 30. 17. Light emission device, in particular for a motor vehicle, comprising a light emission module (10) according to any one of claims 13 to 16. Light emission module with improved guide ply Guide sheet adapted to guide light rays coming from a light emission source (14) intended to be optically coupled to said guide sheet (12). 5 The guide ply has an inlet portion (16) arranged at one end of the guide ply, said end extending along a path (T), the inlet portion comprising a suitable coupling profile for optically coupling the input portion to the light emission source for the penetration of at least part of the light rays coming from the source into the guide ply, the coupling profile extending over at least part of the path (T), the guide sheet further comprising a guide portion (18) optically coupled to the inlet portion and adapted to guide within it at least part of the light rays reaching it from the inlet portion and to form a light beam from said light rays reaching it from the inlet portion.