Light module with microlens array for motor vehicle

Abstract

The invention relates to a light module (1) comprising at least one microlens array device (2) provided with a microlens input array (8) of and a microlens output array (10), characterised in that at least one input microlens (18) is configured to allow a focusing of the light rays (44, 46, 48) arriving on the array of input microlenses (18) in at least two separate focusing zones (26, 30), the rays passing through a first focusing zone (26) being configured to produce a first portion of an illumination beam that the light module (1) participates in implementing, and the rays passing through a second focusing zone (30) being configured to produce a second portion of the illumination beam.

Description

[0001] DESCRIPTION

[0002] Title of the invention: Microlens matrix light module for motor vehicle

[0003] The present invention relates to the field of lighting devices, in particular those capable of equipping a motor vehicle. The present invention relates more particularly to such lighting devices capable of generating at least one lighting function.

[0004] Vehicles, and in particular motor vehicles, are commonly equipped with headlights to generate various lighting functions such as road lighting or signalling the vehicle to other road users. The lighting functions that can be implemented within the lighting devices consist of a dipped beam function and a main beam function.

[0005] Dipped headlights allow a motor vehicle to be seen by other road users and allow its driver to see the road properly up to 50 meters away, without dazzling other road users. High beam headlights emit light beams with a greater range so that the driver of the motor vehicle can see the road properly, at least 100 meters away in night conditions.

[0006] In some applications, the lighting functions are achieved through a microlens array, also known by the acronym MLA for "microlens array".

[0007] The microlens matrix device consists of a block of transparent material capable of allowing light rays to propagate within it, and it may include an occulting element capable of blocking certain of the light rays so as to modulate the associated light function.

[0008] More particularly, the matrix device comprises an array of input microlenses, an array of output microlenses and, where appropriate, a mask interposed between these arrays. The matrix device is configured to form light circulation channels between one of the input microlenses and one of the output microlenses, the mask comprising mask portions respectively arranged in one of the light circulation channels. Each mask portion is provided with at least one opening capable of allowing light rays to pass from the input microlens to the output microlens. The openings in the mask are configured to give a shape to the rays transmitted by the array of input lenses and to allow the array of output lenses to project this shape onto the road.

[0009] All of the mask portions may have the same opening shape, so that the matrix device allows the same lighting function to be performed, or they may have openings of different shapes, distributed regularly within the matrix device and associated with sets of light sources that can be selectively activated to be able to implement this or that lighting function.

[0010] For example, such a matrix device can be implemented to participate in the realization, according to the selective activation of such or such light sources, of a main beam type lighting function or a dipped beam type lighting function.

[0011] Whether for a main beam or dipped beam lighting function, the beam to be projected onto the road may have zones of different light intensity from one zone to another. For example, depending on the regulations in force, it may be necessary to generate a beam with a central zone of increased light intensity, in order to illuminate the roadway in front of the vehicle as much as possible. The lateral zones of the beam can therefore be produced with a lower light intensity, but they should extend as widely as possible to best cover the verges of the roadway.It is known to produce these lighting beams with variable light intensity by combining the implementation within the same projector of a plurality of separate light modules which each ensure the production of a zone of particular light intensity, but it is understood that this solution does not fit into a context of reducing the size of lighting devices.

[0012] The inventors wish to be able to respond to this problem of providing lighting beams with variable light intensity by implementing a microlens matrix device insofar as these devices offer a desired compactness and make it possible to give the functional illuminating surface a great freedom of shape, and therefore a freedom of style for the projector equipped with the matrix device, by means of a discretization by the unit of surface of the input and output microlenses. In this context, the present invention proposes a light module comprising at least one microlens matrix device provided with an input matrix of input microlenses and an output matrix of output microlenses, the matrix device comprising a main optical axis, light emission means configured to emit light rays propagating within the matrix device,said matrix device being configured to form a light beam from said light rays, the matrix device comprising light circulation channels formed along the direction of the optical axis between an input microlens and an output microlens, the light module being remarkable in that at least one input microlens is configured to allow focusing of the light rays arriving on the matrix of input microlenses into at least two distinct focusing zones, the rays passing through a first focusing zone being configured to produce a first part of an illumination beam that the light module participates in implementing, and the rays passing through a second focusing zone being configured to produce a second part of said illumination beam.,

[0013] The microlens matrix device consists of a block of transparent material capable of allowing light rays to propagate within it in a main propagation direction defined here as longitudinal. The matrix device extends longitudinally between an input microlens matrix and an output microlens matrix.

[0014] Each input and output microlens is defined by a curved surface, facing outward from the matrix device, and by the thickness of material extending inside the matrix device. In other words, the profile of the surface has a monotonic variation from a vertex point of said surface towards the edges of said microlens. Thus, said curved surface is convex at all points. This configuration is advantageous in particular for input microlenses, because it allows rays entering through one of said input lenses to remain inside the associated light circulation channel.

[0015] Alternatively, output lenses may have a concave or locally concave surface. Said curved surface is concave at all points, or at certain points only. For example, the surface may have a neck shape, that is, having a concave profile in one direction, and a convex profile in a direction perpendicular to the previous one. One family of surfaces with this characteristic is that of hyperbolic paraboloids.

[0016] Advantageously, each input and output microlens is defined by a continuous surface.

[0017] Advantageously, each input and output microlens is defined by a derivable surface. This feature makes it easier to produce the tool for manufacturing the microlenses.

[0018] Advantageously, each input and output microlens is defined by a second-order differentiable surface. This feature prevents accumulations of light in the resulting beam, thus leading to a beam with good homogeneity.

[0019] According to an optional feature of the invention, certain input and / or output microlenses are defined by a surface having a symmetry of revolution. Advantageously, each input and output microlens is defined by a surface having a symmetry of revolution. The symmetry of revolution makes it possible to simplify the design of said lenses, as well as, in particular when it applies to the output microlens, to ensure good sharpness in the resulting beam.

[0020] The light circulation channels are defined as a strip of the material of the matrix device formed by an input microlens and an output microlens arranged opposite the input microlens if the longitudinal direction is considered. There may not be, within the matrix device, a structural element, such as a partition for example, to generate a physical delimitation between two neighboring channels, but it should be noted that such a partition could be provided, without departing from the context of the invention, in particular to avoid the passage of stray rays from one circulation channel to the other.

[0021] If light flowing through a flow channel is propagated toward the output microlens array, a light function can be performed. If this light comes from a first light source, a first light function can be performed, and if this light comes from a second light source, a second light function can be performed. In both cases, the light involved in performing the light function exits from a common illumination surface, formed by an output surface of the output microlens array.

[0022] According to the invention, and as just mentioned, at least one input microlens is configured to allow focusing of the light rays arriving on the input microlens matrix into at least two distinct focusing zones. This results in at least two distinct projection zones on the target surface of the illumination beam, and therefore the production of different portions of the same illumination beam. By "distinct projection zones" is meant zones having different characteristics, such as for example their shape and / or their luminous intensity, such zones being able to overlap at least partially.A first focusing zone participates in forming a defined portion of the lighting beam implemented by the matrix device and the at least one light source, and a second focusing zone participates in forming another defined portion of this same lighting beam, since implemented by the same matrix device and the same at least one light source. It is thus possible to produce a lighting beam with variable light intensity, by positioning the distinct focusing zones at precise locations of the light module allowing either the projection of a portion of the focused image and therefore at higher light intensity or the projection of a portion of the diffuse image and therefore at lower light intensity.

[0023] By way of non-limiting example, it is thus possible to generate via this matrix device a lighting beam with a high concentration zone, which ensures good visibility for the driver in the center of the lighting beam, and a wide area, which allows the entire width of the road to be illuminated, it being understood that the zones arranged laterally to the high concentration zone and corresponding to the wide area previously mentioned are of lower light intensity.

[0024] According to an optional characteristic of the invention, the input microlens array and the output microlens array are composed of microlenses whose dimensions are of the order of a millimeter, between 0.5 mm and 5 mm.

[0025] More specifically, the projection microlenses may all have a size, in diameter, height and / or width, in front view, less than or equal to 10mm. This makes it possible to limit the thickness of the microlenses, and thus to limit the mass of the part. Furthermore, the projection microlenses may all have a size, in diameter, height and / or width, in front view, greater than or equal to 0.3mm. This makes it possible to manufacture the optical device by a simple injection process to implement. Also, the projection lenses may all have a size, in diameter, height and / or width, in front view, between 1 and 5mm. This allows the projection lenses to be small enough not to be distinguished at the usual observation distance.

[0026] According to an optional feature of the invention, the input microlens is configured to allow focusing on a first focusing zone located inside the light circulation channel and at a distance from the output microlens and on a second focusing zone located in the vicinity of the output microlens and / or beyond the output microlens.

[0027] The interest of this positioning of the focusing zones is notably a function of the configuration of the output microlens associated with the input microlens within the same light circulation channel and the position of the object focus of the output microlens.

[0028] The concepts of "at a distance from" and "in the vicinity of" are to be understood in relation to the longitudinal dimension of the light circulation channel within which the light rays propagate, that is to say the longitudinal dimension between the input microlens and the output microlens associated with this light circulation channel. By "at a distance from", it is understood that an axial distance greater than 10% of the axial dimension of the light circulation channel is meant and by "in the vicinity of", conversely, an axial distance less than or equal to 10% of the axial dimension of the circulation channel.

[0029] The wording "in the vicinity of" and "beyond" should be understood to mean that the second focusing zone is axially offset relative to the first focusing zone in a translational direction along a direction parallel to the main optical axis that runs from the input lens array to the output lens array. The second focusing zone may be in the vicinity of the output microlens, as discussed above, or may be at a greater distance from the output microlens, but outside the array device. According to an optional feature of the invention, the input microlens is configured such that the second focusing zone located in the vicinity of the output microlens is located outside the array device.

[0030] This allows for a homogeneous projected image of the focal plane of the output microlens.

[0031] According to an optional feature of the invention, each output microlens of a light circulation channel is configured to have an object focus located in the vicinity of the first focusing zone in said light circulation channel.

[0032] According to an optional characteristic of the invention, the input microlens comprises at least two distinct portions, including a central portion which ensures the focusing of the rays on the first focusing zone and a peripheral portion which ensures the focusing of the rays on the second focusing zone.

[0033] In other words, the light module is configured such that rays emitted by a light source which encounter the central portion of the input microlens are focused at the output of the input microlens onto the same first focusing zone and the rays emitted by this same light source which encounter the peripheral portion are focused at the output of the input microlens onto the same second focusing zone.

[0034] According to an optional feature of the invention, the input microlens comprises an intermediate portion arranged radially between the central portion and the peripheral portion, said intermediate portion being configured to focus the rays between the first focusing zone and the second focusing zone. It should be noted that all the rays which enter this input microlens at the intermediate portion are focused in an area defined between the first focusing zone and the output microlens, but that rays entering at a first location of the intermediate portion, i.e. at a first radial distance from the center of the input microlens, are focused at a location different from the location at which rays entering at a second location of the intermediate portion are focused, i.e. at a second radial distance from the center of the input microlens.According to an optional characteristic of the invention, the profile of the intermediate portion of the input microlens is such that there is an increasing function between, on the one hand, the radial dimension of impact of the rays emitted by the light source on this intermediate portion and, on the other hand, the axial distance between the focal point of the rays and the first focal zone. Advantageously, said axial distance varies in such a way that said focal point moves from the first focal zone to the second focal zone.

[0035] In other words, the further the rays impact the input microlens from the center, the more the axial distance between the focal point of the rays and the first focusing zone increases. This increasing function can more particularly be strictly increasing and it can consist of an affine function. This increasing function can also start with a horizontal tangent for the rays emitted by the light source having a radial dimension of impact such that they are close to the central portion of the input microlens. Thus, when the distance traveled radially from the edge of said central portion increases, the focused rays first deviate very slowly from the first focusing zone, then more and more quickly.

[0036] According to an optional feature of the invention, said increasing function is continuous. This feature has the advantage, in particular when the axial distance varies such that the focal point moves from the first focal zone to the second focal zone, of producing a beam with an intensity varying progressively from the first part to the second part of said beam. Thus the intensity of the light beam is free from sudden variation, which allows good homogeneity of the light beam.

[0037] According to an optional characteristic of the invention, the light module comprises an optical device associated with the at least one light source, the optical device being configured to direct the light rays emitted by the light emission means which impact it in the direction of the input microlens matrix.

[0038] The optical device may in particular be a reflector, for example of a partially parabolic shape, or consist of a collimator interposed between the light emission means and the matrix of input microlenses. The optical device may in particular be a specific collimator for each input microlens, which allows the light module to perform several light functions, or be a collimator common to all, or a subset, of the input microlenses.

[0039] The optical device is configured to redirect the rays passing through it so as to form at the output a beam of rays substantially parallel to each other and thus to direct these light rays homogeneously towards the associated microlens(es) of the input microlens array. By "substantially parallel" it is understood that the rays may have an angular offset linked to the size of the light source which generates them. After passing through the optical device, the light rays emitted by one or other of the selectively addressable light sources are thus directed homogeneously onto each of the input microlenses.

[0040] According to an optional characteristic of the invention, the matrix device comprises a mask interposed between the input matrix and the output matrix, the mask comprising mask portions respectively arranged in a light circulation channel, each mask portion being provided with an opening capable of allowing light rays to pass from the input microlens to the output microlens associated with this light circulation channel.

[0041] Each input and output microlens is defined by a domed surface, facing outward from the array device, and by the thickness of material extending from the domed surface to the mask, the mask forming the boundary between the input microlens array and the output microlens array.

[0042] If light traveling in a flow channel encounters an opening in the mask portion associated with that flow channel, the light can be propagated toward the output microlens array, thereby performing a light function.

[0043] Conversely, if light traveling in a flow channel does not encounter an opening in the mask portion associated with that channel, the light is blocked by the mask in that channel. It is understood that the mask comprises a plurality of portions and that each of the light flow channels comprises a mask portion that is associated with the flow channel.

[0044] According to an optional feature of the invention, each input microlens is configured so that the first focusing zone is located in the vicinity of the portion of the mask of the associated channel.

[0045] According to an optional feature of the invention, each output microlens of a light circulation channel is configured to present an object focus at the opening formed in the mask portion associated with said light circulation channel.

[0046] According to an optional characteristic of the invention, the object focus of an output microlens of a light circulation channel is arranged substantially on an edge delimiting said opening. This is notably implemented for circulation channels intended to be crossed by light rays participating in forming a lighting function of the dipped beam type for which it is desired to have a clear cutoff of the beam, the cutoff of the beam then being achieved by said edge delimiting the opening on which the object focus mentioned is arranged.

[0047] According to an optional characteristic of the invention, the openings on one edge of which the object focus of an output microlens is arranged have a raised edge forming a cut-off edge of an illumination beam.

[0048] According to an optional feature of the invention, the object focus of an output microlens of a light circulation channel is arranged substantially in the center of said opening. By substantially in the center, it should be understood that this object focus is arranged far from an edge delimiting said opening, which includes for example a position in which the object focus is arranged at two-thirds of a distance between two opposite edges delimiting this opening. This is notably implemented for circulation channels intended to be crossed by light rays participating in forming a high beam lighting function.

[0049] According to an optional feature of the invention, the mask is formed by a glass slide comprising at least one opaque layer deposited on one face of the glass slide, the openings being formed by cutouts in this opaque layer. More particularly, the opaque layer is deposited on the face of the glass slide which is opposite the input microlens array.

[0050] According to an optional characteristic of the invention, the matrix device comprises a plurality of light circulation channels with mask portions, respectively arranged in each of the circulation channels, which have openings of different sizes and / or shapes and which are associated with different and selectively addressable light sources, or sets of light sources.In other words, a first light source, or a set of first light sources, can emit light rays within the matrix device in first light circulation channels in which the mask portions comprise a first type of opening, capable of letting through all or part of the light rays emitted by this first light source, and a second light source, or a set of second light sources, can emit light rays within the matrix device in second light circulation channels in which the mask portions comprise a second type of opening, capable of letting through all or part of the light rays emitted by this second light source.For example, the mask portions present in the first circulation channels have an opening with a cut-off edge to participate in performing a dipped beam lighting function and the mask portions present in the second circulation channels have a wider opening to participate in performing a high beam lighting function.

[0051] The light sources are said to be selectively addressable insofar as they can be activated independently of one another, by an electronic control device. More particularly, when one of the light sources is activated, the other or other light sources are deactivated and only one light source, or only one set of lights, is capable of emitting light rays. In other cases, at least some of the light sources, in particular all the light sources, are switched on simultaneously, which makes it possible to simultaneously generate the respectively associated light functions.

[0052] Light sources can include light-emitting diodes.

[0053] The invention also relates to a lighting device comprising a housing and a glass for closing the housing, the housing and the glass for closing defining an internal volume within which a light module in accordance with the present description is arranged, the light module being arranged inside the internal volume in such a way that the rays which it emits exit through the glass for closing.

[0054] Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and examples of embodiment given for informational and non-limiting purposes with reference to the appended schematic drawings on the other hand, in which:

[0055] [Fig.l] represents a light module according to the present invention, making visible a light source, an optical device and a matrix device, comprising in particular a matrix of input microlenses, a mask and a matrix of output microlenses;

[0056] [Fig.2] represents a detail of the light module of figure 1, namely a light circulation channel formed within the material of the matrix device, figure 2 making visible collimated ray tracings at the input of the matrix device, in the context of the realization of a lighting function of a first type;

[0057] [Fig.3] represents a view similar to that of figure 2, in the context of the realization of a lighting function of a second type;

[0058] [Fig.4] represents an affine function defining the profile of an input microlens of the input microlens array;

[0059] [Fig.5] represents the projection of a portion of the lighting beam implemented by the circulation channel of figure 3, making visible a first central portion of the high intensity lighting beam and a second peripheral portion of the lighting beam.

[0060] It should first be noted that while the figures set out the invention in detail for its implementation, these figures can of course be used to better define the invention, where appropriate. It should also be noted that these figures only set out examples of embodiments of the invention.

[0061] The features, variants and different embodiments of the invention may be combined with each other in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the state of the art.

[0062] In the figures, elements common to several figures retain the same reference.

[0063] In the following description, reference will be made to an orientation that is a function of the Longitudinal, Vertical and Transverse axes as defined by the trihedron L, V, T shown in Figures 1 to 3, with the longitudinal axis L corresponding to the general direction of propagation of the light rays, i.e. the optical axis, and the vertical and transverse axes V, T participating in defining a main elongation plane of the microlens matrix device forming part of the light module, perpendicular to the longitudinal axis L. The choice of names for these axes is not limiting of the orientation that the light module can take, in particular when it is installed in a motor vehicle.

[0064] Figure 1 schematically illustrates a light module 1 comprising a matrix device 2 of microlenses, an optical device 4 and light emission means 6.

[0065] The light emission means 6 may comprise one or more light sources, or one or more sets of light sources. As will be mentioned later, the number of light sources may vary provided that the matrix device is configured accordingly, each of the light sources or each of the sets of light sources then being selectively addressable and in particular capable of being switched on and off independently of one another, for example by means of an electronic control device.

[0066] The optical device 4 and the light emission means 6 are positioned relative to each other so that the light rays emitted by the light source(s) pass through the optical device 4. Here, the optical device 4 is a collimator which is configured to capture light rays emitted by the light emission means and to orient them substantially parallel to each other and to direct them towards the microlens matrix device 2, and more specifically towards an input microlens matrix 8. The microlens matrix device 2 comprises said input microlens matrix 8, an output microlens matrix 10 and a mask 12 interposed between the input microlens matrix 8 and the output microlens matrix 10.In the illustrated example, each microlens array 8, 10 and the mask 12 extend mainly along a vertical and transverse plane, perpendicular to a longitudinal direction L along which the main optical axis 14 of the light module 1 extends. Alternatively, the array device can take an inclined position relative to the main optical axis, in particular to adapt to a curve of the vehicle in which it is to be integrated. This inclined position can be taken by tilting the array device as a whole or by forming steps at the output surface of the array device formed by an external surface of the output microlens array.

[0067] Alternatively, the matrix device could also not have a mask.

[0068] The output surface of the matrix device, i.e. the external surface of the output microlens matrix 10, forms an illumination surface of the light module 1, i.e. a surface through which the light rays exit to generate a light beam outside the vehicle, which is common to each of the light functions capable of being performed by the light module.

[0069] The matrix device 2 is configured to comprise within it light circulation channels 16, extending respectively, in a direction parallel to that of the main optical axis 14, between an input microlens 18 and an associated output microlens 20. The light rays shaped by the collimator which are caused to pass through an input microlens 18 propagate essentially in the light circulation channel 16 associated with this input microlens 18 and they exit the matrix device 2 essentially through the output microlens 20 associated with this light circulation channel.

[0070] The light flow channels are defined as a strip of the material of the matrix device formed by the input microlens array and the output microlens array. In other words, a flow channel is defined by a strip of material of an input microlens and by a strip of material of the output microlens extending in continuity, if we consider the principal optical axis, of said input microlens.

[0071] Each microlens array, input or output, has an external surface and an internal volume, formed by the thickness of material extending from the external surface inwards, the mask being able to form a boundary between the input microlens array and the output microlens array.

[0072] The input microlens array 8 is formed from a plurality of input microlenses 18 juxtaposed next to each other, both in the vertical direction, as visible in FIG. 1, and in the transverse direction. These input microlenses each have a curved surface 22 whose juxtaposition, where appropriate with a longitudinal offset which generates a step from one curved surface to the other, forms the external surface of the input microlens array, and they each have a thickness of material extending between the curved surface 22 and the mask to be able to propagate the light from one to the other.

[0073] According to the invention, at least one input microlens 18 is configured within the matrix device 2 to enable focusing of the light rays arriving at this input microlens into at least two distinct focusing zones. This particular configuration of an input microlens enabling at least two different focusing zones to be generated is notably visible in Figure 2 or Figure 3, on which ray tracings have been made visible.

[0074] The input microlens comprises in particular a central portion 24 which ensures the focusing of rays, arriving on this central portion 24, on a first focusing zone 26 and a peripheral portion 28 which ensures the focusing of rays, arriving on this first peripheral portion 28, on a second focusing zone 30.

[0075] The first focusing zone 26 is located inside the matrix device, where appropriate on the mask 12 when the matrix device is equipped with such a mask, and more particularly on the portion of mask present in the light circulation channel associated with this input microlens.

[0076] The second focusing zone is located in the vicinity of the associated output microlens. Light rays coming from the collimator 4 and passing through this input microlens 18 thus converge towards a first focal point present on the mask 12, in particular to participate in the realization of a first lighting function, or more precisely of a first portion of a lighting beam, while other light rays coming from the collimator and also passing through this input microlens 18 converge towards a second focal point arranged in the vicinity and where appropriate beyond the output microlens, in particular to participate in the realization of a second lighting function, or more precisely of a second portion of this same lighting beam.

[0077] In the illustrated example, the input microlenses 18 are identical to each other.

[0078] In accordance with the arrangement of the input microlens array 18, the output microlens array 10 is formed of a plurality of output microlenses 20 juxtaposed next to each other, both in the vertical direction, as visible in FIG. 1, and in the transverse direction.

[0079] These output microlenses 20 each have, in accordance with what could be mentioned for the input microlenses, a curved surface whose juxtaposition, where appropriate with a longitudinal offset which generates a step from one curved surface to the other, forms the external surface of the matrix of output microlenses, that is to say the output surface of the matrix device, and they each have a thickness of material extending between the mask and the curved surface to be able to propagate the light from one to the other.

[0080] It is notable in the figures schematically representing the matrix device that only the external surface of the input and output microlenses is represented, but it should be noted that each microlens is not just formed by the curved surface but indeed includes the thickness of material which goes from this curved surface 22 to the mask, or to the mask support when there is one.

[0081] Each output microlens 20 is configured within the matrix device 2 such that it has an object focus on the mask 12 and more particularly on the portion of mask present in the light circulation channel associated with this output microlens. For a given light circulation channel 5, the light rays propagating within the matrix device and focused on the first focusing zone 26 by the input microlens 18 thus pass through this object focus of the output microlens 20 and are reoriented by the corresponding output microlens 20 into a beam of rays substantially parallel to the optical axis which participates in forming a light beam to be projected onto the road.

[0082] The ray trace visible in Figure 2 also illustrates light rays propagating within the matrix device 2 by being focused onto the second focusing zone 30 by the input microlens 18. These rays subsequently propagate towards the road scene in front of the vehicle by deviating from the optical axis.

[0083] In this way, the rays focused on the first focusing zone 26 are more particularly intended to form a first portion of a high-intensity lighting beam, due to their propagation on the roadway substantially parallel to the optical axis and to a horizontal plane. Conversely, the rays focused on the second focusing zone 30 are more particularly intended to widen the beam and ensure that the verges of the roadway can be correctly lit, for example.

[0084] The position of the mask 12 within the matrix device 2 may be different from one matrix device to another, as illustrated in FIGS. 1 to 3. The mask 12 could, without departing from the context of the invention, be moved along the main optical axis 14 to move closer to the input microlens array 8 or the output microlens array 10, provided that the microlenses are configured to have a focus on the mask as previously mentioned.

[0085] Furthermore, the position of the mask takes into account the thickness, i.e. the dimension along the longitudinal axis L, of the input microlens array and that of the output microlens array, the thickness of the input microlenses being able to be at least twice that of the output microlenses since there are two output microlenses for each channel for one input microlens.

[0086] Each light circulation channel 16 comprises a portion of the mask 12 extending across the matrix device between the input microlens matrix 8 and the output microlens matrix 10, the mask 12 consisting of a plurality of mask portions 38, 40 juxtaposed with each other and respectively arranged in a light circulation channel 16 of their own.

[0087] The mask portions 12 comprise openings 36, shown schematically in FIGS. 2 and 3, through which the rays deflected by the corresponding input microlens 18 are able to pass to continue their propagation through the matrix device 2. These mask portions 12 thus respectively comprise an opaque part, which blocks the propagation of the light rays when they encounter this opaque part, and a transparent part, formed by the opening and allowing the propagation of the light rays brought to encounter this transparent part.

[0088] The matrix device is made of a transparent material, with here the mask 12 which is formed by a glass slide surrounded by a plastic material, the glass slide comprising at least one opaque layer deposited on one face of the glass slide, the opaque layer being cut, for example by an engraving or laser cutting operation, to produce each of the openings 36. The cut part(s) thus form the transparent part of the mask portions 12 and the remainder forms the opaque part.

[0089] Each output microlens 20 is more particularly configured to have an object focus positioned in the opening 36 forming the transparent part of the mask portion 12 arranged in the light circulation channel 16 corresponding to it. As will be described below, the object focus of the output microlenses 20 can be positioned in a central position of the opening 36 or in an off-center position, and in particular on an edge 42 delimiting the opening 36.

[0090] It is understood that the input microlens 18 is configured, and the mask 12 is positioned relative to this input microlens 18, such that the first focusing zone 26 generated by the input microlens 18 is located at the same place as the object focus of the corresponding output microlens 20, and therefore according to the circulation channels 16 and their mask portion, at the center of the opening or on an edge delimiting the opening.

[0091] Figure 2 illustrates a mask portion of a first type 38, in which the opening 36 extends over substantially the entire height of the light circulation channel 16, to allow substantially all of the collimated light rays to pass through this light circulation channel. This arrangement of the matrix device is particularly suitable for a high beam lighting function, in which beam cutoff is not sought.

[0092] Figure 3 illustrates a mask portion of a second type 40, in which the opening 36 extends over a portion of the height of the light circulation channel, so that the opaque portion filling the remainder of the light circulation channel blocks the passage of a determined quantity of light rays. This arrangement of the matrix device is particularly suitable for a dipped beam lighting function, an edge of the opening participating in delimiting a cut-off edge of the beam making it possible to avoid dazzling other road users. The first focusing zone 26 associated with the input microlens 18 and the object focus of the output microlens 20 are located on this edge delimiting the opening which participates in delimiting the cut-off edge of the beam.

[0093] It should be noted that a matrix device according to the invention may equally well comprise light circulation channels 16 which are all similar to that illustrated in Figure 2, so that the light module is dedicated to performing the high beam type lighting function, or light circulation channels 16 which are all similar to that illustrated in Figure 3, so that the light module is dedicated to performing the low beam type lighting function, but that a matrix device according to the invention may also comprise a combination of each of these light circulations, with a first set of light circulation channels similar to those of Figure 2 and a second set of light circulation channels similar to those of Figure 3.In the latter case, it is understood that the light sources must in this case be dedicated to the illumination of one or other of the sets of circulation channels and that they are addressed selectively according to the lighting function to be carried out.

[0094] In each of the two cases, namely the formation of a beam participating in achieving the main beam lighting function or the formation of a beam participating in achieving the dipped beam lighting function, the configuration of the input microlens makes it possible to generate at least two different focusing zones.

[0095] Figure 2 and Figure 3 make it possible to account for the interest of these two different focusing zones, to realize two specific portions of the lighting function. As an example, Figure 2 shows the propagation of the light rays for the realization of a high beam lighting function, within a light circulation channel 16, it being understood that this propagation is reproduced in several light circulation channels to form at the output of the matrix device a lighting function of appropriate size. It is noteworthy that what will be described is also valid for Figure 2 and the realization of a low beam lighting function, for a part of the rays not blocked by the opaque part of the corresponding mask portion.

[0096] The light source of the light emitting means 6 associated with the light circulation channel 16 is made active by appropriate control of an electronic control device associated with the light module. The light source emits rays towards the collimator 4, and the latter collects these rays and directs them into a beam of rays parallel to each other towards the input microlens matrix of the matrix device 2.

[0097] The collimator 4, or a portion of a collimator common to several light circulation channels, is configured to distribute the light rays over the entire curved surface 22 of the input microlens 18.

[0098] First rays 44 arrive at the central portion 24 of the input microlens and are thus focused on the first focusing zone 26 located on the mask. In other words, all the rays encountering the input microlens at its central portion 24 are directed towards the first focusing zone 26. This first focusing zone 26 being merged or substantially merged with the object focus of the output microlens 20, the first rays 44 propagate to the output microlens 20 and exit the light circulation channel 16 with an orientation substantially parallel to the optical axis, that is to say here to the main optical axis 14 here longitudinal of the light circulation channel 16, between the input microlens 18 and the output microlens 20.These first rays 44 are thus directed precisely in the direction of the optical axis and participate in creating a first part of the lighting beam with high light intensity in a central part 52 of the lighting beam, directed in front of the vehicle, as can be seen in FIG. 5.

[0099] Second rays 46 arrive at the peripheral portion 28 of the input microlens 18 and are thus focused on the second focusing zone 30 located in the vicinity of the output microlens 20 and here downstream of this output microlens, outside the matrix device. In other words, all the rays encountering the input microlens 18 at its peripheral portion 28 are directed towards the second focusing zone 30. Downstream of the output microlens, the second rays continue to propagate away from the optical axis, so that they participate in forming a peripheral portion 54 of the illumination beam, which makes it possible to widen the extent of the illumination beam, as can be seen in FIG. 5.

[0100] Furthermore, third rays 48 arrive on the curved surface 22 of the input microlens 18 on an intermediate portion 50, arranged radially between the central portion 24 and the peripheral portion 28. These third rays 48 are deflected by the input microlens onto a zone arranged longitudinally between the mask and the output microlens, and they participate in forming the essential part of the lighting function, completed by the central part of the beam 52 and the peripheral part 54 previously mentioned, by illuminating a zone arranged between the center of the over-intensified beam and a peripheral ring.

[0101] Figure 4 illustrates how the profile of the intermediate portion is defined, and illustrates examples of how such an intermediate portion is produced.

[0102] More particularly, the profile of the intermediate portion 50 of the entrance microlens 18, and more particularly of the curved surface 22 forming the external surface of the entrance microlens 18, is such that there is an increasing function, and more particularly here affine, between on the one hand the radial dimension Dr of impact of the rays emitted by the light source on this intermediate portion, that is to say the radial distance between the point of impact and the axis of the microlens, and on the other hand the axial distance Dx between the point of focus of the rays and the mask, that is to say the axial distance between this intermediate point of focus and the first point of focus.

[0103] For microlenses with dimensions of the order of 2 mm on each side, the intermediate portion extends radially over a distance ranging from 0.2 mm from the axis of the microlens to 1 mm from this axis.

[0104] For a point of impact of the third rays 48 at the junction of the central portion 24 and the intermediate portion 50, the third light rays 48 are focused substantially at the first focusing zone. For an input microlens of a given circulation channel, the maximum value of the radius, or radial dimension, of the central zone which makes it possible to focus on the first focusing zone, is defined such that the ray caused to propagate by passing through this junction zone between the central portion and the intermediate portion does indeed pass through the output lens associated with this circulation channel. It is understood that if the central portion were larger, said ray, at the junction between the central portion and the intermediate portion, would be lost by touching the lens of another channel.

[0105] The intermediate focusing point gradually moves away from the first focusing zone as the radial distance of the impact bridge of the third rays on the intermediate portion of the input microlens increases. For example, as illustrated by point PI in Figure 4, for an impact point of the third rays at a distance of 0.5 mm from the axis of the input microlens, the intermediate focusing zone is approximately 2.6 mm from the mask.

[0106] The invention as just described makes it possible to meet the aim it set for itself, namely to enable the production of a light module implementing a matrix device and making it possible to generate several portions of the same lighting beam, in particular to create regulatory portions of overcurrent in the center of the beam or widening of the beam at the periphery.

Claims

CLAIMS 1. Light module (1), in particular for a motor vehicle, comprising: at least one microlens matrix device (2) provided with an input matrix (8) of input microlenses and an output matrix (10) of output microlenses, the matrix device (2) comprising a main optical axis (14), light emission means (6) configured to emit light rays (44, 46, 48) propagating within the matrix device (2), said matrix device (2) being configured to form a light beam from said light rays (44, 46, 48), the matrix device comprising light circulation channels (16) formed along the optical axis direction (14) between an input microlens (18) and an output microlens (20), characterized in that at least one input microlens (18) is configured to allow focusing of the light rays (44, 46,48) arriving on the input microlens matrix (18) in at least two distinct focusing zones (26, 30), the rays passing through a first focusing zone (26) being configured to produce a first part of a lighting beam that the light module participates in implementing, and the rays passing through a second focusing zone (30) being configured to produce a second part of said lighting beam., 2. Light module (1) according to claim 1, characterized in that the input microlens (18) is configured to allow focusing on a first focusing zone (26) located inside the light circulation channel and at a distance from the output microlens (20) and on a second focusing zone (30) located in the vicinity of the output microlens (20) and / or beyond the output microlens (20).

3. Light module according to claim 2, characterized in that the input microlens (18) is configured such that the second zone of focusing (30) located in the vicinity of the output microlens (20) and / or beyond the output microlens (20) is located outside the matrix device (2).

4. Light module (1) according to one of the preceding claims, characterized in that the input microlens (18) comprises at least two distinct portions, including a central portion (24) which ensures the focusing of the rays on the first focusing zone (26) and a peripheral portion (28) which ensures the focusing of the rays on the second focusing zone (30).

5. Light module (1) according to claim 4, characterized in that the input microlens (18) comprises an intermediate portion (50) arranged radially between the central portion (24) and the peripheral portion (28), said intermediate portion being configured to focus the rays between the first focusing zone and the second focusing zone.

6. Light module (1) according to claim 5, characterized in that the profile of the intermediate portion (50) of the input microlens (18) is such that there is an increasing function between, on the one hand, the radial dimension (Dr) of impact of the rays emitted by the light source on this intermediate portion and, on the other hand, the axial distance (Dx) between the point of focusing of the rays and the first focusing zone.

7. Light module (1) according to one of the preceding claims, characterized in that each output microlens (20) of a light circulation channel (16) is configured to have an object focus located in the vicinity of the first focusing zone (26) in said light circulation channel (16).

8. Light module (1) according to one of the preceding claims, characterized in that it comprises an optical device (4) associated with the at least one light source, the optical device (4) being configured to direct the light rays emitted by the light emission means (6) which impact it in the direction of the input microlens matrix (8).

9. Light module (1) according to one of the preceding claims, characterized in that the matrix device (2) comprises a mask (12) interposed between the input matrix (8) and the output matrix (10), the mask (12) comprising mask portions respectively arranged in a light circulation channel (16), each mask portion being provided with an opening (36) capable of allowing light rays to pass from the input microlens (18) to the output microlens (20) associated with this light circulation channel.

10. Light module (1) according to the preceding claim, characterized in that each output microlens (20) of a light circulation channel (16) is configured to present an object focus at the opening (36) formed in the mask portion associated with said light circulation channel (16).

11. Light module (1) according to claim 9, when it depends on claim 7, or according to claim 10, characterized in that the object focus of an output microlens (20) of a light circulation channel (16) is arranged substantially on an edge (42) delimiting said opening (36).

12. Light module (1) according to claim 9, when it depends on claim 7, or according to claim 10, characterized in that the object focus of an output microlens (20) of a light circulation channel (16) is arranged substantially in the center of said opening (36).

13. Lighting device comprising a housing and a glass for closing the housing, the housing and the glass for closing defining an internal volume within which is arranged a light module (1) according to any one of the preceding claims, the light module (1) being arranged inside the internal volume such that rays which it emits exit through the glass for closing.

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