WO2021063979A1

WO2021063979A1 - Optical system

Info

Publication number: WO2021063979A1
Application number: PCT/EP2020/077289
Authority: WO
Inventors: Fabrice EGAL
Original assignee: Valeo Vision
Priority date: 2019-09-30
Filing date: 2020-09-30
Publication date: 2021-04-08
Also published as: FR3101391B1; FR3101391A1

Abstract

The invention relates to an optical projection system that comprises: - an input optical group (10) with a first lens (11) and a second lens (12), receiving light rays from a light source (1) and making them converge; - an intermediate optical group (20) comprising a lens (21), the intermediate optical group (20) receiving rays from the input optical group (10) in order to make them diverge; - an output optical group (30) comprising at least one lens (31), the output optical group (30) receiving light rays from the intermediate optical group (20) in order to make them converge.

Description

Title of the invention: Optical system

[0001] TECHNICAL FIELD

The present invention relates in particular to an optical projection system and to a light module for a vehicle.

A preferred application relates to the automotive industry, for vehicle equipment, in particular for the production of devices capable of emitting light beams, also called lighting and / or signaling functions, generally responding to regulations. For example, the invention may allow the production of a light beam of the segmented type, in particular for participation in lighting functions at the front of a vehicle and / or possibly signaling.

[0004] The invention can in particular make it possible to generate a supplementary driving beam (associated with a basic beam totally or at least mainly projected below a horizontal cut-off line of the type used for the low beam function, the main beam complementing the basic beam so as to complete it above the cut-off line); advantageously, this additional high beam is adaptive to turn on or off certain parts of the projected overall beam, for example for anti-glare functions. The invention can also be applied to writing functionalities on the road, or to light projections of welcome scenarios for which lighting is generated in particular when the user is approaching his vehicle.

STATE OF THE ART

[0006] In the automotive sector, there are known devices capable of emitting light beams, also called lighting and / or signaling functions, generally meeting regulations.

[0007] Recently, technologies have been developed which make it possible to produce a segmented beam, also called pixelated, to achieve advanced lighting functions. This is particularly the case for a lighting function of the “roadside” type generally based on a plurality of illumination units. each comprising a light-emitting diode, these diodes being able to be driven individually.

[0008] The beam, resulting from the various beam segments from the diodes, is projected by means of a projection optical system generally comprising one or more lenses. For example, it is possible to produce a main beam, associated with a basic beam totally or at least mainly projected below a horizontal cut-off line of the type used for the low beam function, the main beam adding to the base beam so as to complete it above the cut-off line; advantageously, this additional high beam is adaptive to turn on or off certain parts of the projected overall beam, for example for anti-glare functions. The acronym ADB (for Adaptive Driving Beam meaning adaptive high beam) is used for this type of function.

It will be noted that the invention is in no way limited to the ADB type beams mentioned above but finds an application in the projection of all beams having a segmentation of which one wishes preferably sufficiently precise imaging while keeping a large aperture . These may be bundles with more or less segments, which may be arranged in whole or in part above a cut-off line or below. Some features include dynamic adaptation of beam directions in the event of bends, for example the function known by the acronym DBL (Dynamic Bending Light, for dynamic lighting in curves).

In the present description, called segmented beam, a beam whose projection forms an image composed of beam segments, each segment can be lit independently. A pixelated light source can be used to form these segments. Such a source comprises a plurality of selectively activatable emissive zones.

For reasons of cost price and size, it is necessary to optimize the optical systems for automotive implementations; however, specialized applications such as the production of an ADB beam require sufficient sharpness, in particular to properly isolate the segments of the beam to be switched off, so as to achieve precise shaping of the dark zone without, however, penalizing the general illumination, which itself requires a large numerical aperture.

[0012] An object of the present invention is therefore to provide an optical system which achieves a compromise between the complexity and the optical efficiency, in particular in terms of aperture and sharpness, of the optical system.

[0013] The other objects, characteristics and advantages of the present invention will become apparent on examination of the following description and the accompanying drawings. It is understood that other advantages can be incorporated.

[0014] SUMMARY

To achieve this objective, according to one embodiment there is provided an optical projection system, in particular for a vehicle light module, comprising:

- an input optical group comprising at least a first lens and a second lens, the input optical group being able to receive light rays from a light source and to make them converge;

- an intermediate optical group comprising at least one lens, the intermediate optical group receiving light rays from the input optical group and being configured to make them diverge;

an output optical group comprising at least one lens, the output optical group receiving light rays from the intermediate optical group and being configured to make them converge.

[0016] Thanks to this arrangement, the light emitted by the source is successively processed by the three optical groups of the invention. The sequence of a converging group, a divergent group and a converging group as proposed ensures high definition without requiring the multiplication of lenses. In particular, the invention may be limited to four or five lenses for all of the groups considered. Advantageously, there is no need for an additional projection lens.

Compared to a triplet, optical system typically used, the presence of several lenses, and preferably two lenses, in the input group ensures an increase in the numerical aperture of the projection optical system.

In a preferred embodiment, the output optical group also has several lenses, and in particular two, so that the sharpness is increased, to obtain better resolution.

Advantageously, the angular projection field can be greater than 30 °, which is particularly well suited to the production of ADB type beam.

[0020] Preferably, only spherical components are used, which ensures a reduced manufacturing cost. You can also space the lenses with air knives so that lens bonding is not necessary.

Another aspect relates to a light module, in particular for a motor vehicle, comprising the optical system, and a pixelated light source comprising a plurality of selectively activatable emissive zones. The light module is advantageously configured to produce or participate in producing an ADB beam.

Another aspect relates to a vehicle equipped with at least one module according to the present invention.

[0023] BRIEF DESCRIPTION OF THE FIGURES

The aims, objects, as well as the characteristics and advantages of the invention will emerge better from the detailed description of an embodiment of the latter which is illustrated by the following accompanying drawings in which:

[0025] [Fig.1] Figure 1 shows a schematic view of a module in a first indicative embodiment.

[0026] [Fig.2] Figure 2 shows a schematic view of a module in a second indicative embodiment.

The drawings are given by way of examples and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate understanding of the invention and are not necessarily on the scale of practical applications. [0028] DETAILED DESCRIPTION

Unless specifically indicated to the contrary, technical characteristics described in detail for a given embodiment can be combined with technical characteristics described in the context of other embodiments described by way of example and not by way of limitation.

Options are introduced here that can be implemented, either separately or in any possible combination:

- the distance between the output diopter of the input optical group 10 and the input diopter of the intermediate optical group 20, measured at the edge of said diopters, is less than or equal to 3 mm;

- the distance between the output diopter of the intermediate optical group 20 and the input diopter of the output optical group 30, measured at the edge of said diopters, is less than or equal to 3 mm;

- the input optical group 10, the intermediate optical group 20 and the output optical group 30 are configured so that the system is more open numerically than F / 0.9, and preferably more open than F / 0.75;

- at least all the lenses of the input optical group 10 and of the output optical group 20 are formed of optical glass with a refractive index greater than or equal to 1.7;

the intermediate optical group 20 comprises a single lens 21;

the single lens 21 is bi-concave;

the output optical group 30 consists of a first lens 31 and a second lens 32;

- the optical input group 10 consists of the first lens 11 and the second lens 12;

- all the lenses of the input optical group 10, of the intermediate optical group 20 and of the output optical group 30 are successively spaced apart by an air gap;

- the minimum distance between the light source 1 and the input diopter of the input optical group 10 is greater than or equal to 5 mm.

- the entry face of the first lens of the entry group is flat or concave; a concave surface increases the resolution;

- the second lens, the input group is preferably of biconvex shape; - the input face of the first lens of the output group is flat or concave;

- the input face of the second lens of the output group is flat or convex;

- at least part of the optical surfaces are covered by an antireflection coating;

- the light source is centered on the optical axis of the optical system;

- at least part of the optical surfaces may be microstructured (presence of patterns in relief, the dimensional scale of which is micrometric or nanometric);

- the optical system is included in a box;

- the inner surface of the case has a black diffusive texture;

- all diopters of all lenses of the input optical group, the intermediate optical group and the output optical group are spherical;

- all the lenses of the input optical group 10, of the intermediate optical group 20 and of the output optical group 30 have a "thickness at the center of the lens / useful lens diameter" ratio which does not exceed 1/4 or 0.25 , which means that the useful diameter is at least four times greater than the thickness at the center; the useful surface is the part of the lens through which passes all of the rays contributing to the performance of the system. In the present case, it is typically a circle, because everything is advantageously symmetry of revolution. This useful diameter is generally different from the mechanical diameter: a width of a few millimeters is typically left around the useful diameter to hold the lens or to facilitate its manufacture, the exact value of the mechanical diameter then not having any importance. an optical point of view. Such a ratio makes it possible to ensure optical performance of the optical system, while maintaining a reduced weight and size, which facilitates mounting of the housing of the optical system on a pixelized source support; in particular, the housing of the optical system can be held by simple gluing to a pixelated source support. In this case, precise positioning of the optical system relative to the pixelated source is ensured, even when the housing is cantilevered and / or when subjected to automotive vibratory environments, while manufacturing costs remain low. . Motor vehicle headlights are often provided with one or more light modules arranged in a housing closed by a glass so as to obtain one or more lighting and / or signaling beams at the outlet of the headlight. In a simplified manner, a light module of the housing comprises in particular a light source which emits a light beam, an optical system comprising one or more lenses and, in certain cases, an optical element, for example a reflector, for orienting the light rays coming from light sources, in order to form the output light beam of the optical module. The situation is the same for the rear lights.

The invention can participate in a main beam function which is used to illuminate the scene in front of the vehicle over a large area, but also over a substantial distance, typically around two hundred meters. This light beam, by virtue of its illumination function, is mainly located above the horizon line. It may have a slightly ascending optical axis of illumination, for example. In particular, it can be used to generate a lighting function of the “road supplement” type which forms a portion of a main beam complementary to that produced by a near-field beam, the road supplement seeking entirely or at least mainly to illuminate above the horizon line while the near-field beam (which may have the characteristics of a low beam) seeks to illuminate all or at least mainly below the horizon line.

The device can also be used to train other lighting functions via or outside of those described above in relation to adaptive beams. Notably, a writing function on the ground, particularly at the front of the vehicle, is another potential use. Any other type of beam and any other lighting or signaling function may be affected by the module of the invention.

The module of the invention incorporates at least a light source 1 for generating a segmented type beam to be projected via the optical system.

As shown schematically in Figure 1, the light module according to the invention can successively comprise a light source 1 and an optical system comprising, and preferably consisting of, three lens groups, namely an input optical group 10, an intermediate optical group 20 and an output optical group 30. Rays 2 emitted by the source 1 are processed by the optical system so as to produce projected rays 4. The entire optical system can be organized along an optical axis 3, and the source 1 is preferably centered on the latter.

[0036] The light source 1 can in particular be designed in the form of a matrix of emissive elements in the activation can be controlled individually, to turn off or turn on any of the emissive elements. The shape of the resulting beam is thus varied with a very wide flexibility. For purely illustrative purposes, it is possible to implement a matrix of nine emissive elements, forming nine pixels, arranged in three rows and three columns.

In a manner known per se, the present invention can use light sources of the light-emitting diode type also commonly called LEDs. It may possibly be organic LED (s). In particular, these LEDs can be equipped with at least one chip using semiconductor technology and capable of emitting light. Furthermore, the term light source is understood here to mean a set of at least one elementary source such as an LED capable of producing a flux leading to the generation of at least one light beam at the output of the module of the invention. In an advantageous embodiment, the output face of the source is of rectangular section, which is typical for LED chips.

Preferably, the light-emitting source comprises at least one matrix of monolithic light-emitting elements, also called a monolithic matrix. In a monolithic matrix, the light emitting elements are grown from a common substrate and are electrically connected so as to be selectively activatable, individually or by subset of light emitting elements. The substrate can be predominantly made of a semiconductor material. The substrate can comprise one or more other materials, for example non-semiconductor. Thus each electroluminescent element or group of electroluminescent elements can form a luminous pixel and can emit light when its or their material is supplied with electricity. The configuration of such a monolithic matrix allows the arrangement of selectively activatable pixels very close to each other, compared to conventional light-emitting diodes intended to be soldered onto printed circuit boards. The monolithic matrix within the meaning of the invention comprises electroluminescent elements of which a main dimension of elongation, namely the height, is substantially perpendicular to a common substrate, this height being at most equal to one micrometer.

Advantageously, the monolithic matrix (s) capable of emitting light rays can be coupled to a unit for controlling the light emission of the pixelated source. The control unit can thus control (we can also say control) the generation and / or the projection of a light beam pixelated by the lighting device. The control unit can be integrated into the lighting device. The control unit can be mounted on one or more of the dies, the whole forming a light module. The control unit may include a central processing unit coupled with a memory on which is stored a computer program which includes instructions allowing the processor to perform steps generating signals allowing control of the light source. The control unit can thus, for example, individually control the light emission of each pixel of a matrix. Further, the luminance obtained by the plurality of electroluminescent elements is at least 60Cd / mm2, preferably at least 80Cd / mm2.

The control unit can form an electronic device capable of controlling the electroluminescent elements. The control unit can be an integrated circuit. An integrated circuit, also called an electronic chip, is an electronic component reproducing one or more electronic functions and being able to integrate several types of basic electronic components, for example in a reduced volume (ie on a small plate). This makes the circuit easy to set up. The integrated circuit can be for example an ASIC or an ASSP. An ASIC (acronym for "Application-Specific Integrated Circuit") is an integrated circuit developed for at least one specific application (that is to say for a customer). An ASIC is therefore a specialized integrated circuit (microelectronics). In general, it brings together a large number of unique or tailor-made features. An ASSP (acronym for "Application Specifies Standard Product") is an integrated electronic circuit (microelectronics) grouping together a large number of functionalities to satisfy a generally standardized application. An ASIC is designed for a more particular (specific) need than an ASSP. The monolithic matrices are supplied with electricity via the electronic device, itself supplied with electricity using, for example, at least a connector connecting it to a source of electricity. The source of electricity can be internal or external to the device according to the invention. The electronic device supplies the light source with electricity. The electronic device is thus able to control the light source.

[0041] According to the invention, the light source preferably comprises at least one monolithic matrix, the electroluminescent elements of which project from a common substrate from which they have grown respectively. Different arrangements of light-emitting elements can meet this definition of a monolithic matrix, provided that the light-emitting elements have one of their main dimensions of elongation substantially perpendicular to a common substrate and that the spacing between the pixels, formed by a or more electroluminescent elements grouped together electrically, is small compared to the spacings imposed in known arrangements of flat square chips soldered to a printed circuit board.

In particular, the light source according to one aspect of the invention may comprise a plurality of electroluminescent elements distinct from the others and which are grown individually from the substrate, being electrically connected so as to be selectively activatable, if necessary. by subsets within which rods can be activated simultaneously.

According to an embodiment not shown, the monolithic matrix comprises a plurality of electroluminescent elements, of submillimeter dimensions, which are arranged projecting from a substrate so as to form rods of hexagonal section. The electroluminescent rods extend parallel to the optical axis of the light module when the light source is in position in the housing. These electroluminescent rods are grouped together, in particular by electrical connections specific to each assembly, in a plurality of selectively activatable portions. The electroluminescent rods originate on a first face of a substrate. Each electroluminescent rod, here formed by using gallium nitride (GaN), extends perpendicularly, or substantially perpendicularly, projecting from the substrate, here made from silicon, other materials such as silicon carbide being able to be used without go beyond the context of the invention. For example, the electroluminescent rods could be made from an alloy of aluminum nitride and gallium nitride (AIGaN), or from an alloy of aluminum phosphides, indium and gallium (AlInGaP). Each electroluminescent rod extends along an axis of elongation defining its height, the base of each rod being disposed in a plane of the upper face of the substrate.

The electroluminescent rods of the same monolithic matrix advantageously have the same shape and the same dimensions. They are each delimited by an end face and by a circumferential wall which extends along the axis of elongation of the rod. When the electroluminescent rods are doped and subjected to polarization, the resulting light at the output of the semiconductor source is emitted essentially from the circumferential wall, it being understood that light rays can also emerge from the face. terminal. It follows that each electroluminescent rod acts as a single light-emitting diode and that the luminance of this source is improved on the one hand by the density of the light-emitting rods present and on the other hand by the size of the illuminating surface defined by the circumferential wall. and which therefore extends over the entire circumference, and the entire height, of the rod. The height of a rod can be between 2 and 10 μm, preferably 8 μm; the largest dimension of the end face of a rod is less than 2 μm, preferably less than or equal to 1 μm.

It is understood that, during the formation of the electroluminescent rods, the height can be changed from one zone of the light source to another, so as to increase the luminance of the corresponding zone when the height average of the sticks constituting it is increased. Thus, a group of electroluminescent rods may have a height, or heights, different from another group of electroluminescent rods, these two groups being constitutive of the same semiconductor light source comprising electroluminescent rods of submillimeter dimensions. The shape of the electroluminescent rods can also vary from one monolithic matrix to another, in particular on the section of the rods and on the shape of the end face. The rods have a generally cylindrical shape, and they may in particular have a shape of polygonal section, and more particularly hexagonal. It is understood that it is important that light can be emitted through the circumferential wall, whether the latter has a polygonal or circular shape.

[0047] Furthermore, the end face may have a substantially planar shape and perpendicular to the circumferential wall, so that it extends substantially parallel to the upper face of the substrate, or else it may have a domed or pointed shape. at its center, so as to multiply the directions of emission of the light leaving this end face.

The electroluminescent rods are arranged in a two-dimensional matrix. This arrangement could be such that the sticks are staggered. In general, the rods are arranged at regular intervals on the substrate and the separation distance of two immediately adjacent electroluminescent rods, in each of the dimensions of the matrix, must be at least equal to 2 μm, preferably between 3 μm and 10 μm. pm, so that the light emitted by the circumferential wall of each rod can exit from the array of electroluminescent rods. Furthermore, it is expected that these separation distances, measured between two axes of extension of adjacent rods, will not be greater than 100 µm.

According to another embodiment not shown, the monolithic matrix may comprise light-emitting elements formed by layers of epitaxial light-emitting elements, in particular a first layer of n-doped GaN and a second layer of p-doped GaN, on a substrate single, for example made of silicon carbide, and which is cut (by grinding and / or ablation) to form a plurality of pixels respectively originating from the same substrate. The result of such a design is a plurality of electroluminescent blocks all coming from the same substrate and electrically connected so as to be selectively activatable from one another.

In an exemplary embodiment according to this other embodiment, the substrate of the monolithic matrix may have a thickness of between 100 μm and 800 μm, in particular equal to 200 μm; each block can have a width and width, each being between 50 μm and 500 μm, preferably between 100 μm and 200 μm. In one variant, the length and the width are equal. The height of each block is less than 500 μm, preferably less than 300 μm. Finally, the exit surface of each block can be made via the substrate on the side opposite to the epitaxy. The separation distance between two pixels. The distance of the contiguous pixels may be less than 1 μm, in particular less than 500 μm, and it is preferably less than 200 μm.

Concerning the monolithic chips with electroluminescent blocks:

- The number of pixels can be between 250 and several thousand. A typical value around a thousand pixels.

- Their overall shape is usually square, and can also be rectangular. Form ratio generally between 1: 1 and 1: 5.

The size of a unit pixel (square in all known cases, perhaps rectangular) is between 100 and 300 μm in the current state of the art.

According to another embodiment not shown, both with electroluminescent rods extending respectively projecting from the same substrate, as described above, as with electroluminescent blocks obtained by cutting superimposed electroluminescent layers on the same substrate, the monolithic matrix may further include a layer of a polymer material in which the electroluminescent elements are at least partially embedded. The layer can thus extend over the entire extent of the substrate or only around a determined group of electroluminescent elements. The polymer material, which may in particular be based on silicone, creates a protective layer which makes it possible to protect the electroluminescent elements without hindering the diffusion of light rays. In addition, it is possible to integrate in this layer of polymer material means of wavelength conversion, and for example phosphors, capable of absorbing at least part of the rays emitted by one of the elements and of converting at least part of said absorbed excitation light into emission light having a wavelength different from that of the excitation light. It is equally possible to provide that the phosphors are embedded in the mass of the polymer material, or that they are placed on the surface of the layer of this polymer material. The light source may further include a coating of reflective material to deflect the light rays to the output surfaces of the pixelated source.

The light-emitting elements of submillimeter dimensions define in a plane, substantially parallel to the substrate, a determined exit surface. It is understood that the shape of this exit surface is defined according to the number and the arrangement of the electroluminescent elements which compose it. It is thus possible to define a substantially rectangular shape of the emission surface, it being understood that the latter can vary and take any shape without departing from the context of the invention.

The embodiment shown in Figure 1 has five lenses arranged downstream of a light source 1 whose emissive surface is represented by a plane from which rays 2 emerge in the direction of an entrance face of a first lens 11 of an optical input group 10 of lenses.

It will be seen that FIG. 2 shows a variant with four lenses.

Advantageously, an optical glass is used having a refractive index at least equal to 1.7 to produce the lenses, and at least those of the input optical group 10 and of the output optical group 30. The shapes of the lenses The faces of the lenses are described below in more detail, it being generally considered that they are advantageously of circular cross section. Furthermore, it is preferred that the faces of the lenses, forming diopters with the surrounding air, are spherical in nature.

In the case of Figure 1, the optical input group 10 comprises a first lens 11 having an input face (or diopter) (advantageously concave, but may also be planar) and a convex output face. Such as represents the path of the light rays, this lens 11 provides a first convergence.

This convergence is completed by a second lens 12 of the optical input group 10, the latter being biconvex. The constringence of the input optical group 10 is advantageously high, and at least higher than that of the intermediate optical group 20 described below.

The light rays leaving the input optical group 10, advantageously reach a second group, called the intermediate optical group 20. Preferably, it consists of a biconcave lens 21. The useful edge of the input face of the lens 21 is preferably spaced at most 3 mm from that of the lens which precedes it, that is to say the last lens of the optical input group 10; this limited spacing is favorable to the optical resolution and, the preservation of a space between the lenses facilitates the assembly of the optical system, in particular by sparing gluing.

The intermediate optical group 20 causes the light rays to diverge in the direction of a third group, called the output optical group 30. The latter, like the first, has a convergent function. It comprises a first lens 31 of convergent nature, having an entrance face which is either flat, concave or convex and whose exit face is convex. Preferably, as described in relation to the input optical group 10, the spacing between the intermediate optical group 20 and the output optical group 30 is limited, in particular to 3 mm at the working edge of the adjacent lenses of the two groups.

In the embodiment shown in Figure 1, the output optical group 30 comprises a second lens 32 whose input face may be planar or convex and whose output face is convex.

After this path, the rays 4 leaving the system can be projected, advantageously directly, towards the outside of the vehicle.

FIG. 2 shows an alternative embodiment with four lenses. The first group, optical input group 10, always has two lenses. Likewise, the intermediate optical group 20 here still consists of a lens with two concave faces. However, the optical output group 30 does not include then more than a single lens 31. Obviously, the sharpness obtained is less than the previous case, but the size is also less. Depending on the optical and size requirements of the application, one or the other of these two embodiments can be used, however not limiting the invention.

Thanks to the invention, a clear projection can be obtained, preferably with a numerical aperture greater than or equal to F / 0.9 or even F / 0.75 and over an angular sector advantageously greater than or equal to 30 °.

The invention is not limited to the embodiments described above

Claims

[Claim 1] Optical projection system, in particular for a vehicle light module, characterized in that it comprises:

- an input optical group (10) comprising at least a first lens (11) and a second lens (12), the input optical group (10) being able to receive light rays coming from a light source ( 1) and to make them converge;

- an intermediate optical group (20) comprising at least one lens (21), the intermediate optical group (20) receiving light rays from the input optical group (10) and being configured to make them diverge;

- an output optical group (30) comprising at least one lens (31), the output optical group (30) receiving light rays from the intermediate optical group (20) and being configured to make them converge.

[Claim 2] System according to the preceding claim, in which the distance separating the output diopter of the input optical group (10) and the input diopter of the intermediate optical group (20), measured at the level of the edge of said diopters, is less than or equal to 3 mm.

[Claim 3] A system according to any preceding claim, wherein the distance between the output diopter of the intermediate optical group (20) and the input diopter of the output optical assembly (30), measured at the edge. of said diopters, is less than or equal to 3 mm.

[Claim 4] A system according to any preceding claim, wherein the input optical group (10), the middle optical group (20) and the output optical group (30) are configured so that the system is more numerically open than F / 0.9, and preferably more open than F / 0.75.

[Claim 5] A system according to any preceding claim, wherein all the lenses of at least the input optical group (10) and the output optical group (20) are formed of optical glass with a higher refractive index. or equal to 1, 7.

[Claim 6] A system according to any preceding claim, wherein all of the lenses of the input optical group (10), the middle optical group (20) and the output optical group (30) have a "thickness" ratio. at the lens center / useful lens diameter ”which does not exceed 0.25.

[Claim 7] A system according to any preceding claim, wherein the intermediate optical group (20) comprises a single lens (21).

[Claim 8] A system according to the preceding claim, wherein the single lens (21) is bi-concave.

[Claim 9] A system according to any preceding claim, wherein the output optical assembly (30) consists of a first lens (31) and a second lens (32).

[Claim 10] A system according to any preceding claim, wherein the input optical assembly (10) consists of the first lens (11) and the second lens (12).

[Claim 11] A system according to any preceding claim, wherein all the lenses of the input optical group (10), the intermediate optical group (20) and the output optical group (30) are successively spaced apart by a air blade.

[Claim 12] A light module, in particular for a motor vehicle, comprising a system according to any one of the preceding claims and a pixelized light source (1) comprising a plurality of selectively activatable emissive zones.

[Claim 13] A light module according to the preceding claim, in which the minimum distance separating the light source (1) and the input diopter of the input optical group (10) is greater than or equal to 5 mm.