Light module configured to project at least one cut-off light beam

Abstract

The present invention relates to a light module (1) comprising a light source (2), a collimator (4), and a microlens array device (6), wherein the microlens array device (6) comprises a plurality of light passage ducts (14) comprising an entrance microlens (20) and an exit microlens (22), wherein each incident light ray (10) falls within an angular range of incidence (12), and each refracted light ray falls within an angular range of refraction (30), and wherein the entrance microlenses (20) are offset so as to form steps (44), wherein an angle (a) between a step (44) and a reference direction (R) lies between a first bound (36) defining the angular range of incidence (12) and a second bound (42) defining the angular range of refraction (30).

Description

[0001] DESCRIPTION

[0002] Title: Light module configured for the projection of at least one cut-off light beam

[0003] The present invention relates to the field of light modules intended to equip vehicles, and more particularly to such light modules adapted to follow the curve of the bodywork of the vehicles with which they are fitted.

[0004] Vehicles, and in particular motor vehicles, are commonly equipped with headlights that can generate various lighting functions, which in particular allow for road lighting or signaling the vehicle to other users. Lighting corresponds to a main beam function or a cut-off lighting function, namely a dipped beam function. Signaling corresponds, for example, but is not limited to, a position light function or a direction indicator light function.

[0005] For reasons of style and aesthetics, for example, the light modules can be designed to follow certain surfaces of the vehicles they are intended to equip, for example an outer window of the headlight or a front face of the vehicle. These surfaces of the vehicles are not always flat, so it is necessary to adapt the light modules so that they follow these non-flat surfaces. Furthermore, it is also possible to be in the presence of an outer window or a front face that is substantially flat, and to want to create a light module that deviates from it in order to create an impression of depth. In both cases, the light modules are configured in such a way that their output face, that is to say their face intended to be opposite the outer window or the front face, has a controlled and adapted shape.

[0006] In certain applications, the realization of one of the aforementioned light functions is enabled by the emission of light rays by a light source through a microlens array device, also known by the English acronym MLA for microlens array. A microlens array device notably comprises light circulation channels respectively formed by an input microlens and an output microlens, which are respectively focused so that the light rays entering through an input microlens propagate in the microlens array device through a dedicated light circulation channel to exit through the output microlens associated with this light circulation channel.

[0007] In particular, microlens matrix devices are known with an opaque mask within them and on either side of which are attached an array of input microlenses and an array of output microlenses, each array being focused on the mask and openings formed in the mask. Also known are microlens matrix devices without a mask, with an array of output microlenses which is directly attached to the array of input microlenses, and with input microlenses which converge on the corresponding output microlens and output microlenses which are focused on the corresponding input microlens.

[0008] It is of interest to produce a microlens matrix device by plastic injection to give a particular curvature to this microlens matrix device, in particular by offsetting the entry faces of the entry microlenses and / or the exit faces of the exit microlenses from each other. In this, it is particularly advantageous not to have an interposed mask, because this is produced by an opacified glass plate, and this harms the flexibility of the production.

[0009] In the context of plastic injection of the microlens matrix device, it is necessary to provide draft angles from a circulation channel to the adjacent channel to allow the part to be demolded after injection.

[0010] However, the presence of a clearance angle, necessary for mechanical reasons, must not have optical consequences. It is therefore important to avoid, within the microlens matrix device, the propagation of stray light rays which would prevent or disrupt the implementation of the chosen lighting function. The management of stray rays is all the more important in a microlens matrix device without a mask, the mask usually helping to prevent these stray rays.

[0011] The present invention falls within this context and thus has as its main subject a light module for a motor vehicle configured for the projection of at least one light beam along an optical axis of said light module, the light module comprising at least one light source, a collimator and a microlens matrix device, the light source being configured to emit light rays towards the microlens matrix device through the collimator, the microlens matrix device comprising a main input face intended to receive incident light rays from the light source and having passed through the collimator, a main output face opposite the main input face, and a plurality of light circulation conduits comprising an input microlens and an output microlens,each light circulation conduit being delimited by an input face participating in forming the main input face and an output face participating in forming the main output face, the light module being configured so that each incident light ray received by the main input face is included in an angular range of incidence and each light ray refracted through the main input face to propagate within a light circulation channel in the direction of the main output face is included in an angular range of refraction, at least some of the input microlenses being offset relative to the other input microlenses so as to form steps between two adjacent input microlenses,at least one step being configured so that an angle between the step and a reference direction of the light module is between a first terminal delimiting the angular range of incidence relative to this reference direction and a second terminal delimiting the angular range of refraction relative to this reference direction.,

[0012] The light module according to the invention is intended to equip a motor vehicle for the performance of at least one light function, the light beam generated by the light module for the performance of this light function being projected along an optical axis of the light module.

[0013] The light module comprises one or more light sources intended to emit light rays towards a collimator. The role of this collimator is to transform the light rays emitted by the light source and direct them towards a matrix device into a beam of incident light rays parallel to each other. The incident light rays arriving at the matrix device are more precisely parallel to the divergences related to the dimensions and parameters of the different elements forming the light module. Thus, each incident light ray falls within an angular range of incidence delimited by two angular value limits relative to a reference direction. The microlens matrix device, or "microlens array" (MLA), is made of an injectable material, for example a plastic material.The microlens array device comprises a plurality of light circulation conduits intended to propagate the incident light rays arriving at the array device. These light circulation conduits extend between an input face opposite the collimator and an output face, this input face and this output face also respectively fitting into a main input face of the microlens array device and into a main output face of the microlens array device. Each light circulation conduit is composed of an input microlens and an output microlens, with the input microlens comprising the input face of this light circulation conduit and the output microlens comprising the output face of this light circulation conduit.

[0014] The input microlens and the output microlens are here in continuity with each other; in other words, they are attached to each other within the light circulation conduit. More precisely, there is no mask interposed between the input microlens and the output microlens. In this context, each input microlens can be configured to converge the rays on the corresponding output microlens, i.e. configured so that an image focus is substantially positioned on the output microlens and each output microlens can then be configured to image the corresponding input microlens, i.e. configured so that an object focus is substantially positioned on the input microlens.Alternatively, each microlens each input microlens may be configured to have an image focus that is coincident, or substantially coincident taking into account manufacturing tolerances, with an object focus of an output microlens associated with it. Alternatively still, microlenses of each of the preceding types may be located in the same microlens array device.

[0015] The light rays leaving the collimator are received by the main input face, more particularly by the input faces of different light circulation conduits, and they pass through an input face to propagate within the microlens matrix device towards the output faces, a light ray propagating in the thickness of the matrix device being a ray refracted by the input microlens. Within the microlens matrix device, in particular due to the angular range of incidence mentioned above, each refracted light ray falls within an angular range of refraction delimited by two angular value limits relative to a reference direction.

[0016] For a given point on an input face of the matrix device, the angular range of incidence illustrates the fact that several incident light rays can arrive on this input face with a variable angle of incidence, and the angular range of refraction illustrates the fact that several refracted light rays can propagate within the light circulation channel from this input face with a variable angle of refraction. The presence of these angular ranges is mainly due to the fact that the light sources are not point-like but have an extended surface. More precisely, the divergence generating this angular range is defined by the lateral dimension of the light source related to the focal length of the collimator. This divergence, or angular range of incidence, is the angle under which the light source is seen at the distance of the focal length of the collimator.Thus, the larger the source, the greater the divergence, for the same focal length. Alternatively, for the same source size, the shorter the focal length, the greater the divergence. Possible optical aberrations may be a secondary cause contributing to the enlargement of these angular ranges.

[0017] It is notable that the angular range of refraction may be an angular range of different extent from that of the angular range of incidence, due to the refraction of the rays included in this angular range of incidence on the entry face, the angle of refraction depending on the curvature of this entry face and the index of the material forming the microlens matrix device.

[0018] It should also be noted that for incident rays, the directions are all parallel, except for the divergence. The divergence is the same regardless of the area of ​​incidence on the entrance face. For refracted rays, the divergence is also the same regardless of the area on the entrance face, but the directions can change. The reference direction corresponds, within the light module, to a direction parallel to the optical axis and passing through an entry point of a given light ray in a given entrance microlens. We thus understand that there is a reference direction associated with each light ray.

[0019] The main input face of the microlens matrix device is not planar; in fact, the input microlenses do not all extend in the same plane and at least some of them are offset relative to the others. In one embodiment, it may be envisaged that each of the input microlenses is offset relative to the other input microlenses, and alternatively it may be envisaged that certain adjacent microlenses are not offset, in particular when several, for example a pair, of these input microlenses are associated with the same light circulation channel.

[0020] In this way, there is an offset, or step, between two adjacent input microlenses, and in particular between two adjacent input faces. This offset is to be considered axially, with reference to the optical axis of the light module or to the reference direction previously mentioned. More particularly, this offset from one input face to the other is to be considered in the main elongation direction of the light circulation conduit.

[0021] In the context of producing a light module by injection, these steps must have an angle relative to the main elongation direction of the light circulation conduits, which has a sufficient value to allow the part to be demolded. The orientation of these steps must therefore meet mechanical requirements requiring the existence of an angle, known as the draft angle.

[0022] In order to limit the presence of stray light rays within the microlens array device, preferably to prevent any stray light rays, this step between two adjacent input microlenses has a predefined angle depending on the orientation of the incident and refracted rays. The orientation of the steps must therefore meet optical requirements.

[0023] The angle is configured to prevent the passage of light rays through the step, either directly by an incident light ray without having encountered an entry face or indirectly by a refracted light ray after it has been deflected upon passing an entry face. Thus, the light module is configured so that the light rays enter through the entry faces of the entry microlenses rather than through the steps, and propagate within the light circulation channel after passing through an entry face without being reflected at the step.

[0024] The characteristic of the invention, according to which an angle between the step and a reference direction of the light module is between a first terminal delimiting the angular range of incidence relative to this reference direction and a second terminal delimiting the angular range of refraction relative to this reference direction, is particularly valid for refracted rays originating from incident rays arriving on the entry face in the immediate vicinity of the step. Immediate proximity means a distance of value less than 10% of the dimension, in the corresponding direction, of the entry face considered.

[0025] In the foregoing, and throughout the document, microlenses are referred to, but it should be noted that minilenses can be referred to in a similar manner, without departing from the context of the invention. According to an advantageous embodiment of the invention, the projection lenses, whether called microlenses or minilenses, all have a size, in diameter, height and / or width, in front view, less than or equal to 10 mm. This makes it possible to limit the thickness of the lenses, and thus to limit the mass of the part. According to an advantageous embodiment of the invention, these projection lenses all have a size, in diameter, height and / or width, in front view, greater than or equal to 0.3 mm. This makes it possible to manufacture the optical device by an injection process that is simple to implement.Furthermore, according to an advantageous embodiment of the invention, the projection lenses all have a size, in diameter, height and / or width, in front view, of between 1 and 5 mm. This allows the projection lenses to be small enough not to be distinguished at the usual observation distance.

[0026] According to a characteristic of the invention, at least 50% of the steps of the main entrance face have an angle between the first terminal and the second terminal; preferably, at least 80% of the steps of the main entrance face have such an angle between the first terminal and the second terminal.

[0027] The light module can be configured to implement a cut-off lighting function. The lighting function has, for example, an upper horizontal cut-off in the case of dipped beam headlights or a lateral cut-off in the case of an adaptive anti-glare lighting system, also known as a "matrix beam".In this context of a light module comprising a matrix device and allowing the realization of a cut-off lighting function, the fact of controlling the value of the clearance angle between two adjacent microlenses defining adjacent light circulation channels makes it possible to realize this function with a matrix device without a mask without having a function penalized by too large a number of stray light rays, which are blocked by the presence of the mask in the case of a matrix device with a mask interposed between the input microlenses and the output microlenses.

[0028] According to an optional characteristic of the invention, the first terminal corresponds to an incident light ray of the angular range of incidence closest to the reference direction and the second terminal corresponds to a refracted light ray of the angular range of refraction closest to the reference direction.

[0029] The first terminal corresponds to the incident light ray, for a given angular range of incidence, likely to form the smallest angle with the reference direction. The second terminal is the refracted light ray, for a given angular range of refraction, likely to form the smallest angle with the reference direction. Depending on the upward or downward inclination of the incident light rays, that is to say depending on whether these incident rays form an angle with the reference direction, measured from this reference direction towards one of the incident light rays, which is respectively a negative angle or a positive angle, the first terminal can form a negative or positive angle with the reference direction and the second terminal forms an angle with the reference direction in the opposite direction.

[0030] According to an optional characteristic of the invention, the inlet faces of the light circulation conduits are offset relative to each other in a direction parallel to the reference direction.

[0031] In other words, the input faces of the light circulation conduits are offset relative to each other along a main elongation direction of the light circulation conduits. The input faces are, for example, offset relative to each other along a direction parallel to the optical axis. Within the main input face of the microlens matrix device, it is the presence of the steps that induces the offset between the input faces of the different light circulation conduits.

[0032] According to an optional characteristic of the invention, the inlet faces of the light circulation conduits are offset according to a monotonic function.

[0033] It is understood that the input faces receiving the incident light rays from the light source follow either an increasing function or a decreasing function. According to the embodiments, and in particular in the presence of a plurality of light sources, the input faces of the light circulation conduits are shifted according to a piecewise monotonic function.

[0034] According to an optional characteristic of the invention, the inlet faces of the light circulation conduits are respectively arranged symmetrically around an axis parallel to the reference direction.

[0035] Similarly, the outlet faces of the light circulation ducts are respectively arranged symmetrically around an axis parallel to the reference direction. Due to the presence of the steps, and the angle that they form with the reference direction, the parallel axes on which the inlet faces are centered are not confused with the parallel axes on which the outlet faces are centered.

[0036] According to an optional feature of the invention, at least some of the steps that are arranged between input faces of the microlens matrix device intended to receive incident rays coming from the same light source are parallel to other steps. Thus, if the light module is configured to follow exclusively a vertical curve, all the steps are parallel to each other, in a substantially horizontal orientation. Similarly, if the light module is configured to follow exclusively a horizontal curve, all the steps are parallel to each other, in a substantially vertical orientation. If steps are formed within the microlens matrix device so that it can follow both a horizontal curve and a vertical curve, the parallelism of the steps to each other is to be considered in a given section plane, including the reference direction.

[0037] According to an optional characteristic of the invention, the steps become larger and larger as they move away from the optical axis.

[0038] The dimension of a given step extending between a first input microlens and a second adjacent input microlens corresponds in particular to its dimension, measured substantially along the main elongation direction of the light circulation conduit, between the input face of the first input microlens and the input face of the second input microlens.

[0039] According to an optional feature of the invention, at least some of the light circulation conduits have different thicknesses than the other light circulation conduits, the thickness of a light circulation conduit being measured between an inlet face and an outlet face of this conduit.

[0040] Such a thickness is for example measured between a central point of the input face and a central point of the output face, and for example parallel to the reference direction when an axis parallel to this direction passes through the two end faces of the conduit. The different thickness of the light circulation conduits between them helps to facilitate the adaptation of the main output face of the microlens matrix device to a shape of the vehicle.

[0041] According to an optional characteristic of the invention, the light module comprises an additional light source, the incident rays from the light source and the incident rays from the additional light source having, at the collimator output, different angles of incidence.

[0042] The additional light source may allow the same light function to be performed, and in particular the light function with cut-off, as the light source, in which case the light module is single-function. Alternatively, the additional light source may allow the performance of a light function different from the light function with cut-off, in which case the light module is dual-function. This light function is, for example, a signaling light function; in any case, it is a light function without cut-off.

[0043] According to an optional feature of the invention, the light module comprises a partition arranged between the incident rays from the light source and the incident rays from the additional light source. This partition may in particular be opaque.

[0044] According to an optional characteristic of the invention, at least some of the input faces of the light circulation conduits receiving the incident rays from the additional light source are offset relative to the other input faces in a direction parallel to the reference direction, these input faces being offset according to a monotonic function.

[0045] According to an optional feature of the invention, the monotonic function followed by the input faces receiving the incident rays from the light source and the monotonic function followed by the input faces receiving the incident rays from the additional light source are different functions. This is then a piecewise monotonic function for the main input face. The monotonic function followed by the input faces receiving the incident rays from the light source and the monotonic function followed by the input faces receiving the incident rays from the additional light source are, for example, in opposite directions to each other. For example, these monotonic functions may be symmetrical.

[0046] According to an optional characteristic of the invention, the divergence of the collimated beam, i.e. coming from the collimator, is between 1.4 and 3°. More particularly, for characteristic sizes of light-emitting diode between 0.2mm and 2mm and a collimator with a focal length between 10mm and 100mm, the divergence of the collimated beam can be between 0.1° and 12°, with a value of 0.1° for a source of 0.2mm and a focal length of 100mm and a value of 12° for a source of 2mm and a focal length of 10mm. In a common case of light sources having a side between 0.5mm and 1mm and a collimator focal length of approximately 20mm, the divergences are between 1.4 and 3°. The dimensions of the light source and the focal length of the collimator are the parameters that most influence the divergence of the collimated beam.

[0047] According to an optional feature of the invention, the convergence of the input microlenses is between -6° and 6°. In other words, the rays refracted inside the lens are refracted at an angle relative to the optical axis within this range. More particularly, considering the limiting cases where the refracted rays converge on a point located on the output face and where the input surface has almost no optical power, the angles of these refracted rays are within an interval of + / - arctan((lens_height / 2) / lens_thickness). For a lens with a side length of 1mm and a thickness of 5mm, the refracted rays can be between + / -5.7°, or approximately + / -6° if potential aberrations are taken into account.More generally, for a given image focal length of the input lens, the angles of the refracted rays are within an interval of + / - arctan((lens_height / 2) / image focal length of the input lens).

[0048] The convergence of the input microlenses helps to determine an extent of the angular range of refraction for the refracted light rays. Other characteristics, details and advantages of the invention will emerge more clearly from reading the description which follows on the one hand, and from exemplary embodiments given for informational and non-limiting purposes with reference to the appended drawings on the other hand, in which:

[0049] [Fig. 1] illustrates, schematically, a first embodiment of the light module according to the invention, the light module comprising a light source, a collimator and a microlens matrix device, light rays arriving on the microlens matrix device being plunging light rays;

[0050] [Fig. 2] illustrates, schematically, a ray tracing as it passes through a main input face of the microlens matrix device, with in particular the representation of different beams of incident light rays arriving on the input face and different corresponding refracted light rays, the figure also making visible the presence of steps between two adjacent input faces of the matrix device, the inclination of these steps being dependent on the inclination of the incident and refracted light rays;

[0051] [Fig. 3] illustrates, schematically, the light module of figure 1 with an alternative embodiment of its microlens matrix device;

[0052] [Fig. 4] illustrates, schematically, a second embodiment of the light module according to the invention, the light module comprising a plurality of light sources, the collimator and the microlens matrix device.

[0053] [Fig. 5] illustrates, schematically, the light module of the first embodiment with light rays arriving on the ascending microlens matrix device, this figure highlighting an inclination of the steps which is correctly adapted to an inclination of the incident light rays;

[0054] [Fig. 6] illustrates, schematically, the light module of the first embodiment with ascending light rays, this figure highlighting an inclination of the steps which is not adapted to the inclination of the incident light rays and which leads to parasitic rays;

[0055] [Fig. 7] illustrates, schematically, the light module of the first embodiment with ascending light rays, this figure highlighting an inclination of the steps which is correctly adapted to an inclination of the refracted light rays;

[0056] [Fig. 8] illustrates, schematically, the light module of the first embodiment with ascending light rays, this figure highlighting an inclination of the steps which is not adapted to the inclination of the refracted light rays and which leads to a phenomenon of total internal reflection.

[0057] 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 and / or to differentiate the invention from the prior art.

[0058] In the figures, elements common to several figures retain the same reference.

[0059] Figures 1 to 4 thus illustrate, schematically, a light module 1 according to the invention, according to a first embodiment for Figures 1 to 3 and 5 to 8 and according to a second embodiment for Figure 4.

[0060] The light module 1 is configured to be arranged within a motor vehicle, for example behind a closing window of a headlight arranged in a front face of said vehicle. More particularly, the light module 1 is intended to equip the motor vehicle, with a view to performing at least one of its lighting functions, in an area of ​​the vehicle which has a curve and the light module 1 is configured to have an exit face for the light rays participating in performing the lighting function which substantially follows the curve of this area of ​​the vehicle.

[0061] In the first embodiment, the light module 1 is more particularly intended for implementing a cut-off lighting function, which may for example correspond to a dipped beam lighting function, with a cut-off of the beam projected by the light module which is an upper horizontal cut-off. Alternatively, the light function corresponds to a lighting function performed by an adaptive anti-glare lighting system, which makes it possible to obtain a matrix lighting beam comprising vertical strips and which can be selectively switched off so as not to dazzle road users without reducing the light intensity of the rest of the beam, and the cut-off is then a lateral cut-off.Furthermore, the light module as it will be described is particularly advantageous in the case of application for a lighting function with cut-off, insofar as it makes it possible to properly control the appearance of stray rays which can be detrimental for such a function, but it should be noted that this light module making it possible to control the appearance of stray rays could also be implemented for a signaling function or a lighting function without cut-off.

[0062] In the second embodiment, the light module 1 may be either a single-function light module or a dual-function light module. In the presence of a single-function light module, this light function may in particular correspond to the aforementioned cut-off light function. In the presence of a dual-function light module, this light module may in particular be capable of providing, in addition to the cut-off light function, a non-cut-off light function. Such a non-cut-off light function may in particular consist of a signaling function.

[0063] The various components of the light module 1 will now be detailed. The light module 1 comprises at least one light source 2, a collimator 4 and a microlens matrix device 6. In the first embodiment and as can be seen in FIG. 1 in particular, the light module 1 comprises a single light source 2. In the second embodiment and as illustrated in FIG. 4, the light module has this light source 2 as well as an additional light source 8. It is understood from the above that the additional light source 8 is, in the case of a single-function light module 1, assigned to performing the light function with cut-off, in a manner complementary to the role of the first light source 2, and that it is, in the case of a dual-function light module 1, assigned to performing the light function without cut-off.

[0064] Everything that will be described subsequently in relation to the first embodiment, that is to say with only the light source 2, is intended to apply mutatis mutandis to the second embodiment with the light source 2 and the additional light source 8, unless otherwise stated.

[0065] The light source 2, the collimator 4 and the microlens matrix device 6 are arranged relative to each other, with the collimator interposed between the light source 2 and the microlens matrix device 6, such that the rays emerging from the microlens matrix device 6 form a light beam 100 projected along an optical axis O of the light module 1 onto a road scene upstream of the motor vehicle.

[0066] The light beam is produced by the optical processing of the light rays emitted by the light source 2. More particularly, the light source 2 emits a plurality of light rays towards the microlens matrix device 6, through the collimator 4. Within the collimator 4, the light rays coming from the light source 2 are collimated, that is to say they are made parallel to each other. Thus, at the exit of the collimator 4, in other words between this collimator 4 and the microlens matrix device 6, the light rays are in the form of a beam of collimated rays aligned parallel to each other and directed towards an input face of the microlens matrix device. In the remainder of the description, this beam of collimated rays will be considered according to its impact on said input face so that the light rays which form it will be called incident light rays 10.

[0067] Furthermore, it should be noted that, if in the remainder of the description, the collimator will be described with reference to a lens, the collimator can, without departing from the context of the invention, be formed of several lenses, each of these lenses forming a collimator being intended to illuminate a specific zone of the matrix device. Advantageously, the beams coming from different collimators which do not overlap, even partially.

[0068] More particularly, the light source 2 is arranged on a focal plane of the collimator-forming lens 4 so that the light rays exiting the collimator form said beam of collimated rays and the light source and / or the collimator are offset relative to the optical axis so that the beam of collimated rays here has as a whole an angle of inclination relative to the optical axis in its propagation between the collimator 4 and the microlens matrix device 6.

[0069] It should be noted that the parallelism of the incident light rays 10 with respect to each other to form the collimated beam of rays is not perfectly observed within the light module 2. Thus, the incident light rays 10 are considered to be parallel provided that divergences related to the dimensions and parameters of the different components of the light module 2 are omitted. Each incident light ray 10 must thus be considered as being able to extend within an angular range of incidence 12, the extent of which reflects the divergent nature of the optical system as a whole. Such an angular range of incidence 12 is more particularly illustrated in FIG. 2.For a given point of an input face 24, the incident light ray 10 which theoretically arrives at this point with a given angle of incidence may arrive with a different angle of incidence due to the dimensioning tolerances of the optical system and possible optical aberrations, this different angle of incidence being included in said angular range of incidence. This angular range of incidence 12 and the impact that this has on the shape to be given to the microlens matrix device and in particular to a main input face 16 of this microlens matrix device 6 will be detailed below.

[0070] The dimensions and parameters of the light module 2 which can influence the formation of divergences and thus an extent of the angular range of incidence 12 are mainly dimensions of the light source 2 and a focal length of the collimator 4.

[0071] Furthermore, in the presence of a plurality of light sources, namely in the second embodiment with the light source 2 and the additional light source 8 illustrated in FIG. 4, both this light source 2 and this additional light source 8 emit rays through the collimator 4 and the distinct position of these sources on the focal plane involves, independently of the divergence phenomena induced by this collimator 4, incident light rays 10 from the light source 2 which are not parallel to incident light rays 10 from the additional light source 8. In other words, the incident light rays 10 emitted by the light source 2 and the incident light rays 10 emitted by the additional light source 8 form different angles of incidence with respect to a reference direction R, here substantially parallel to the optical axis O.The incident light rays 10 from the light source 2 and the incident light rays 10 from the additional light source 8 therefore extend in intersecting directions. The incident light rays 10 emitted by the light source 2 propagate towards the microlens matrix device 6 at a positive angle to the optical axis O and the incident light rays 10 emitted by the additional light source 8 propagate at a negative angle to this optical axis. The input faces of the matrix device onto which these incident light rays are directed are configured to straighten the rays in a suitable manner to be able to form the desired illumination beam 100 at the output and therefore mainly along the optical axis O, so that input faces which are intended to straighten rays with a positive angle cannot straighten rays with a negative angle of incidence.In this context, as illustrated in the second embodiment, the light module 1 can be equipped with a partition 13. This partition 13 is arranged between the collimator 4 on the one hand and the microlens matrix device 6 on the other hand. The partition 13, advantageously opaque, makes it possible to separate the incident light rays 10 coming from each light source 2, 8 and thus prevents any interaction between incident light rays 10 and a part of the microlens matrix device for which these incident light rays are not intended.

[0072] The incident light rays 10 which exit from the collimator 4, whether they come from the light source 2 or from the additional light source 8, are intended to pass through the microlens matrix device 6 before exiting from the light module 1 in the form of an illumination beam, and in particular a cut-off illumination beam. This microlens matrix device 6 is composed of a plurality of light circulation conduits 14, arranged next to each other and above each other, which extend between a main input face 16 of the microlens matrix device 6 and a main output face 18 thereof. The main input face 16 of the microlens matrix device 6 is arranged opposite the collimator 4 while its main output face 18 is opposite it.

[0073] Each light circulation conduit 14 is more particularly formed of an input microlens 20 and an output microlens 22 which are here attached to each other. In other words, the microlens matrix device 6 is devoid of a mask which would otherwise be interposed between the input microlens 20 and the output microlens 22. It follows from this that the microlens matrix device 6 is formed of a matrix of input microlenses and a matrix of output microlenses attached to each other.

[0074] In this configuration, each light circulation conduit 14 extends in a main elongation direction while being delimited by an entry face 24, which belongs to its entry microlens 20 and which participates in forming the main entry face 16 of the microlens matrix device 6, as well as by an exit face 26 which belongs to its exit microlens 22 and which participates in forming the main exit face 18 of the microlens matrix device 6. A thickness E of the light circulation conduits 14 corresponds to their dimension measured between their entry face 24 and their exit face 26. Such a thickness E is different from one circulation conduit 14 to another.A reduction or increase in the thickness E of the light circulation conduits 14 leads to variant embodiments of the microlens matrix device 6, with for example a first variant embodiment shown in FIG. 1 in which the microlens matrix device 6 is less thick than the microlens matrix device 6 of FIG. 3, which corresponds to a second variant embodiment.

[0075] As can be seen in the figures, the inlet faces 24 of all the light circulation conduits 14 are centered on axes parallel to the reference direction R and to the optical axis O. By centered, it should be understood here that the inlet faces are arranged substantially symmetrically around an axis parallel to the reference direction. In the same way, the outlet faces 26 of all the light circulation conduits 14 are centered on axes parallel to the reference direction R. And the main elongation direction of each of the light circulation channels 14, respectively formed between an inlet face 24 and an outlet face 26, is substantially parallel to this reference direction R and to the optical axis O.

[0076] The incident light rays 10 enter the microlens matrix device 6 by refraction at the main input face 16 of the microlens matrix device 6, more particularly via the input faces 24 of its various light circulation conduits 14. The light rays propagate within the various light circulation channels of the microlens matrix device 6 and then exit from the latter via its main output face 18, more precisely via the output faces 26 of its various light circulation conduits 14.

[0077] The input microlenses 20 are configured such that the light rays 28 refracted by an input face 24 of an input microlens 20 converge towards the output face 26 of the output microlens 22 associated with said input microlens. More particularly, in the application of a light module intended to produce a cut-off beam without a mask interposed between the input and output microlenses, each input microlens 20 is configured to converge, within the light circulation conduit 14, the refracted light rays 28 towards the output microlens 22 associated with it, and each output microlens 22 images the input face 24 of the corresponding input microlens 20.It is understood that these refracted light rays 28 are not strictly parallel to each other, in particular due to the fact that the incident light rays 10 at the origin of these refracted rays can have a variable angle of incidence depending on the aberration and optical tolerances of the system. For a given point on an input face of the microlens matrix device, a theoretical incident light ray, impacting the input face with a theoretical angle of incidence, is refracted into a theoretical refracted light ray, with a theoretical angle of refraction, but a real incident light ray, impacting this given point on the input face with an angle of incidence different from the theoretical angle of incidence can generate a refracted light ray with an angle of refraction different from the theoretical angle of refraction.This results, for each refracted light ray 28 coming from a given point of an input face of the matrix device, in an angular range of refraction 30 which comprises, around said refracted light ray 28, a plurality of possible refraction angles that the refracted ray coming from the given point can take. The value of such an angular range of refraction 30, particularly visible in FIG. 2, can also be impacted by the convergence of the input microlenses 20. For example, the convergence of the input microlenses 20 is between -6° and 6°.

[0078] The angular range of incidence 12 and the angular range of refraction 30 will now be detailed in relation to FIG. 2. As explained above, an angular range of incidence 12 surrounds each incident light ray 10 and an angular range of refraction 30 surrounds each refracted light ray 28. The angular range of incidence 12 illustrates the fact that several light rays leaving the collimator can arrive at the same point on the entrance face 24 of a given entrance microlens 20 with a variable angle of incidence, in particular due to optical aberrations and specific dimensions of the light module. Similarly, the angular range of refraction 30 illustrates the fact that several light rays can propagate within the light circulation channel from the same point on the entrance face 24 of the given entrance microlens 20, with refraction angles that vary.

[0079] The angular range of incidence 12 is delimited by two limits, which correspond to the two extreme incident light rays 32, 34 most inclined with respect to the theoretical incident light ray 10, represented in solid lines in particular in FIG. 2. These two extreme incident light rays 32, 34 are respectively represented in mixed lines and in dashed lines, and they are located on either side of a given incident light ray 10. These two extreme incident light rays 32, 34 are the collimated rays likely to impact the entry face at the same point as the theoretical incident light ray 10 with respectively the angle of incidence, measured with respect to the reference direction R, the largest and the smallest.More precisely, one of the extreme incident light rays, here a first extreme incident light ray 32, forms a smaller angle than the other with the reference direction R, so that it is likely to arrive flatter on the entrance face, that is to say with an angle of inclination which tends to bring this first ray closer to the optical axis compared to the inclination of the theoretical incident ray. This first extreme incident light ray 32 which forms the angle of the smallest absolute value with the reference direction R corresponds to a first terminal 36 of the angular range of incidence 12, which will be used subsequently to define shapes of the microlens matrix device 6, the other extreme incident light ray serving to define the other terminal of this angular range of incidence 12. The first terminal 36 is defined as forming a first angle α1 with the reference direction R.

[0080] In the same way, the angular range of refraction 30 is delimited by two limits which correspond to the two most divergent refracted light rays 38, 40 which are located on either side of a theoretical refracted light ray 28, represented in solid lines in particular in FIG. 2. These two most divergent refracted light rays 38, 40, respectively represented in mixed lines and dashed lines, result here from the refraction of the extreme incident light rays 32, 34 previously mentioned. These two most divergent refracted light rays 38, 40 are the refracted rays capable of propagating from the entry face at the same point as the theoretical refracted light ray 28 with respectively the largest and smallest refraction angle, measured relative to the reference direction R.More precisely, one of the diverging refracted light rays, here the first diverging refracted light ray 38, has the largest angle with the reference direction R and forms a boundary of the angular range of refraction 30 and the other of the diverging refracted light rays, here the second diverging refracted light ray 40, has the smallest angle with the reference direction R and corresponds to another boundary of the angular range of refraction, here a second boundary 42 which will be used subsequently to define shapes of the microlens matrix device 6. The second boundary 42 is defined as forming a second angle a2 with the reference direction R.As can be seen in the figures, the main input face 16 of the microlens matrix device 6 is not planar; the input microlenses 20 are offset from each other, and therefore the input faces 24 of the light circulation conduits 14 are also offset from each other. More particularly, the input faces 24 of the light circulation conduits 14 are offset from each other in a direction parallel to the reference direction R and to the optical axis O.

[0081] As illustrated in Figures 1 and 2, the input faces 24 of the light circulation conduits 14 are shifted following a monotonic function, which tends either to bring them closer to the collimator 4 or to move them away from it. In the particular case of the second embodiment shown in Figure 4, the input faces 24 of the light circulation conduits 14 are shifted following a piecewise monotonic function; thus, the input faces 24 receiving the light rays from the light source 2 are shifted according to a first monotonic function and the input faces 24 receiving the light rays from the additional light source 8 are shifted according to a second monotonic function.Here, the first monotonic function is for example increasing starting from the optical axis O, that is to say that it tends to bring the input microlenses 20 closer to the collimator 4 as it moves away from the optical axis O, and the second monotonic function which corresponds to the part of the matrix device extending on the other side of a plane passing through the optical axis O is also increasing starting from the optical axis O, since it also tends to bring the input microlenses 20 closer to the collimator 4 as it moves away from the optical axis O. The main input face 16 is thus substantially symmetrical on either side of a plane passing through the optical axis O.The output faces 26 of the light circulation conduits 14 follow the same monotonic or piecewise monotonic function as the corresponding input faces 24, except in the case of the variant embodiment illustrated in FIG. 3 for which, due to the different thickness of the light circulation conduits 14, the output faces 26 do not follow a monotonic function.

[0082] The offset between the input microlenses 20 is such that the main input face 16 has a staircase-shaped profile, with a step 44 formed between two directly adjacent microlenses 20. More particularly, in this staircase-shaped profile, the input faces 24 form risers which extend mainly in a plane perpendicular to the optical axis, and the steps 44 connect the input faces two by two.

[0083] Each step 44 thus corresponds to a portion of the input microlens which forms a connection between the input face 24 of an input microlens 20 and the input face 24 of the input microlens 20 which is adjacent to it.

[0084] It should be noted that the input microlens matrix is ​​obtained by injection, into a suitable mold, of a transparent plastic or thermoplastic material, such as polycarbonate (PC) for example. The steps 44 must thus have a draft angle oc, relative to the main elongation direction of the light circulation channel, that is to say relative to the reference direction R, which has a sufficient value to allow the injection-molded part to be extracted from its mold during a demolding operation. For example, the minimum value of the draft angle a can be of the order of 1°.

[0085] In this, the inclination of the steps responds to mechanical constraints of manufacturing the part. As will now be described, this inclination is also provided according to the invention to respond to optical constraints, so as to advantageously limit the appearance of parasitic rays within the microlens matrix device due to the presence of these steps.

[0086] As is particularly visible in Figure 2, the steps 44 are substantially parallel to the incident light rays 10. In the presence of a plurality of light sources, as is the case for the second embodiment of Figure 4, the steps 44 of the entry faces 24 receiving the incident light rays 10 from the light source 2 are substantially parallel to these incident light rays 10, while the steps 44 of the entry faces 24 receiving the incident light rays 10 from the additional light source 8 are substantially parallel to said incident light rays 10.

[0087] Generally, the steps 44 formed between input faces intended to receive incident rays from the same beam of collimated rays are substantially parallel to each other. For the second embodiment, the steps 44 of the input faces 24 receiving the incident light rays 10 from the light source 2 are parallel to each other and the steps 44 of the input faces 24 receiving the incident light rays 10 from the additional light source 8 are parallel to each other. However, due to the symmetry of the monotonic functions followed by the input faces 24 associated with each light source 2, 8, the steps 44 of the input faces 24 receiving the incident light rays 10 emitted by the light source 2 and the steps 44 of the input faces 24 receiving the incident light rays 10 emitted by the additional light source 8 are not parallel to each other.

[0088] Furthermore, in the embodiments shown, it is notable that the steps 44 become larger and larger as they move away from the optical axis O, in particular to accompany the characteristic of difference in thickness and more particularly an increase in thickness as they move away from the optical axis O. Such a dimension of the steps 44 is for example measured between the entrance face 24 of a given entrance microlens 20 and the entrance face 24 of the entrance microlens 20 which is directly adjacent to it.

[0089] As mentioned, within the light module 1, the presence of steps 44 could induce interference which would be due either to parasitic light rays resulting from the entry of the incident rays into the microlens matrix device 6 via said steps 44 and not via the entry faces, or else from the entry of the incident rays via an entry face but with an angle implying that they encounter a step within the microlens matrix device and are totally reflected upon encountering this step 44. In order to avoid such interference, the angle of inclination α formed between a given step 44 and the reference direction R must, according to the invention, be considered as a function of the inclination of the rays propagating upstream and downstream of one of the entry faces adjacent to said step.

[0090] More precisely, the angle a formed between a given step 44 and the reference direction R is between the first terminal 36, defined by the inclination of an extreme incident ray on a given contact point of the entry face, and the second terminal 42, defined by the inclination of an extreme refracted ray from said given contact point of the entry face. It is understood from the above that the angle a formed between a given step 44 and the reference direction R must have a value between the first angle a1 and the second angle a2, that is to say between the smallest angle formed between an incident light ray of the angular range of incidence 12 and the reference direction R on the one hand, and the smallest angle formed between a refracted light ray of the angular range of refraction 30 and the reference direction R on the other hand.

[0091] It should be noted that in the context of the first embodiment, Figures 1 to 3 illustrate a light module 1 for which the incident light rays 10 are plunging or descending, that is to say that each of these incident light rays 10 forms an angle, measured from the reference direction R to said incident light ray 10, which is a positive angle. Figures 5 to 8 will now be described in more detail, in which within the light module 1 the incident light rays 10 are represented as being ascending rays; in other words, each of these incident light rays 10 forms an angle, measured from the reference direction R to said incident light ray 10, which is a negative angle.

[0092] In accordance with what has been mentioned previously, the inequality, according to which the angle a of the step 44 is included on the one hand between the first angle al formed between the first terminal 36 and the reference direction R and on the other hand between the second angle a2 formed between the second terminal 42 and this reference direction R, is always verified, whether the orientation of the incident light rays 10 is plunging or ascending. The orientation of the incident light rays 10 however has an impact on the orientation of the steps 44, which are substantially parallel to these incident light rays 10 and which therefore have in the case illustrated in Figures 5 to 8, with ascending rays, an inclination such that the step angle, or clearance angle, is a negative angle if we consider the angle starting from the reference direction R.

[0093] Figures 5 and 6 provide a better schematic understanding of the benefit of respecting the inequality with regard to incident light rays 10, while Figures 7 and 8 provide a better schematic understanding of the benefit of respecting the inequality with regard to refracted light rays 28.

[0094] Figure 5 thus illustrates a case in which the angle α between the step 44 and the reference direction R is correctly chosen with respect to an angle measured between one of the incident light rays 10 and the reference direction R, this angle corresponding here to the first angle α1. Conversely, Figure 6 illustrates a case for which the choice of the angle α between the step 44 and the reference direction R is not adapted with respect to the first angle α1. Similarly, for the refracted light rays 28, Figure 7 represents a case where the angle α between the step 44 and the reference direction R is correctly chosen with respect to the second angle α2 measured between one of the refracted light rays 28 and the reference direction R, while Figure 8 shows a choice of step angle α which is not adapted with respect to this second angle α2.It is understood from the above that figures 5 and 7 correspond to cases in which the light module 1 correctly implements its light function due to compliance with the inequality specific to the invention, by virtue of which the angle a is between the angle al of the first terminal 36 and the angle a2 of the second terminal 42, whereas conversely figures 6 and 8 present cases in which this inequality is not respected and present the resulting parasitic rays, which is likely to lead to a malfunction of the light module 1.

[0095] In Figure 5, the angle a measured between the step 44 and the reference direction R is less than the angle al measured between the first terminal 36 and the reference direction R, this first terminal 36 corresponding as a reminder to the first extreme incident light ray 32 which forms the angle of the smallest absolute value with the reference direction R. As a result, the incident light rays 10 arriving on the main input face 16 of the microlens matrix device 6 cannot penetrate into the microlens matrix device 6 via the step 44, thus preventing the formation of stray light rays. The incident light rays 10 all penetrate into the microlens matrix device 6 via one of the input faces 24 and almost all of the incident light rays 10 are refracted by these input faces 24 to propagate in the light circulation channel dedicated to them.

[0096] On the contrary, in Figure 6 the angle a measured between the step 44 and the reference direction R is greater than the angle a1. The angle of the step is thus unsuitable here because the incident light rays 10 can enter the microlens matrix device 6 via the step 44. Such light rays likely to enter via the step 44, which are in this Figure 6 illustrated in the form of white arrows, are undesirable because they are not correctly straightened by the entry face 24 of one of the entry microlenses 20 and they subsequently propagate in a direction not conforming to the desired propagation direction, that is to say by converging towards the exit face associated with the entry face. As such, these rays entering via the step 44 risk disturbing the formation of a homogeneous and regulatory light beam 100, and therefore hindering the implementation of the light function performed by the light module 1.

[0097] Thus, when the inequality according to which the angle a is less than the angle al is not respected, an adequate functioning of the light module 1 is disturbed.

[0098] In Figure 7, the angle a measured between the step 44 and the reference direction R is greater than the angle a2 measured between the second terminal 42 and the reference direction R, this second terminal 42 corresponding as a reminder to the second extreme refracted light ray 40 which forms the angle of the smallest absolute value with the reference direction R. As a result, the inclination of the step 44 is sufficiently open to prevent the refracted light rays 28 having penetrated into the microlens matrix device 6 from meeting this step 44 directly after the entry face at the level of which they were refracted. A total internal reflection of the refracted light rays 28 against said step 44 is therefore advantageously avoided.

[0099] On the other hand, in Figure 8 the angle a measured between the step 44 and the reference direction R is less than the angle a2. The step angle a is thus unsuitable because some of the refracted light rays 28, and in particular those having a refraction angle a2, are likely to encounter the step 44 and consequently to undergo the phenomenon of total internal reflection. In this Figure 8, a refracted light ray 28 being totally reflected within the microlens matrix device 6 after having struck the step 44 is illustrated in the form of a white arrow. The formation of such light rays is undesirable within the light module 1 because it poses a risk of degradation of the light beam 100 and consequently of the light function implemented by the light module 1.

[0100] Therefore, when the inequality that angle a is greater than angle α2 is not satisfied, the proper operation of the light module 1 is hampered.

[0101] According to the invention, it is thus sought that at least one step 44, if possible all the steps, is configured with a clearance angle, that is to say an angle a between this step and the reference direction R, which satisfies the following inequality: al < a < a2, with a: angle between the step 44 and the reference direction R, being equal to the clearance angle, al: angle of the first terminal 36 delimiting the angular range of incidence 12 relative to the reference direction R, a2: angle of the second terminal 42 delimiting the angular range of refraction 30 relative to the reference direction R.

[0102] In the context of the embodiments shown in relation to the light source 2, namely for a microlens matrix device 6 whose input faces 24 are offset according to an increasing monotonic function which tends to bring the input faces 24 closer to the collimator as they move away from the optical axis O, for incident light rays 10 which form positive angles with respect to the reference direction R, that is to say plunging incident light rays 10, the steps 44 correspond to an addition of material with respect to a light circulation conduit 14 which would be straight, that is to say substantially parallel to the reference direction R. The steps 44 thus follow the positive inclination of the incident light rays 10.Similarly, when the input faces 24 are shifted according to an increasing monotonic function but the incident light rays 10 form negative angles with respect to the reference direction R, that is to say ascending incident light rays 10, as is the case for the incident light rays 10 coming from the additional source 8 of FIG. 4, the steps 44 correspond to an addition of material with respect to a straight light circulation conduit 14.Conversely, in a case not illustrated here where the input faces 24 of the microlens matrix device 6 would be offset according to a decreasing monotonic function tending to move the input faces 24 away from the collimator as they move away from the optical axis O, incident light rays 10 with positive angles relative to the reference direction R would give rise to steps 44 which would correspond to a withdrawal of material relative to a straight light circulation conduit 14.

[0103] The incident and refracted rays shown in the figures correspond to certain particular configurations. For example, in Figure 2 the incident rays are included in a downward angular range, and the refracted rays are included in an upward angular range. In other words, all the incident rays are oriented downwards and all the refracted rays are oriented upwards, when considered in the direction of travel of the light. However, other configurations are possible. The incident rays can, for example, be included in an angular range distributed around the reference direction R. Thus, some incident rays are downward and other incident rays are upward.In other words, the two extreme incident light rays 32, 34 of the angular range are distributed on either side of the reference direction R, that is to say that one forms a positive angle and the other forms a negative angle with respect to said reference direction R. Similarly, the refracted rays can be included in an angular range distributed around the reference direction R. Furthermore, the incident rays can also be included in an ascending angular range. Furthermore, the refracted rays can also be included in a descending angular range.

[0104] In Figure 2, the path of the rays is oriented from the right to the left of the figure, that is, the optical axis O is oriented positively from the right to the left of the figure, and the reference direction as well. We place ourselves according to this orientation, the angles being measured in the trigonometric direction (also counterclockwise).

[0105] In Figure 2, each of the two extreme incident light rays 32, 34 makes a positive angle with the reference direction R. As seen previously, the first extreme incident angle 32 makes a smaller angle with the reference direction R than the angle that the second extreme incident angle 34 makes with said reference direction R.

[0106] Likewise, it has been seen previously that the first extreme refracted ray 38 makes a larger angle with the reference direction R than the angle that the second extreme refracted angle 40 makes with said reference direction R, that is to say that the absolute value of the angle of the first extreme refracted ray 38 is larger than the absolute value of the angle of the second extreme refracted ray 40. However, these two angles being negative, the angle of the first extreme refracted ray 38 is smaller than the angle of the second extreme refracted ray 40, when their values ​​are considered as real numbers.

[0107] Thus, in general, the angular range of incidence has a lower angular limit of incidence formed by the first extreme incident ray 32 and an upper angular limit of incidence formed by the second extreme incident ray 34. Each of the angular limits may have a positive or negative value, or one of them may be zero, i.e. the corresponding extreme incident ray is parallel to the reference direction R. Similarly, in general, the angular range of refraction has a lower angular limit of refraction formed by the first extreme refracted ray 38 and an upper angular limit of refraction formed by the second extreme refracted ray 40. Each of the angular limits may have a positive or negative value, or one of them may be zero, i.e. the corresponding extreme refracted ray is parallel to the reference direction R.

[0108] The angle that the step 44 makes with the reference direction R must then be between a first terminal 36, called the upper terminal, corresponding to the lower angular incidence terminal, and a second terminal 42, called the lower terminal, corresponding to the upper angular refraction terminal. For this, the lower angular incidence terminal must be greater than the upper angular refraction terminal.

[0109] This is valid in the case where the input microlenses 20 forming the step 44 are offset relative to each other so that the input microlens located above the step 44 is placed behind the input microlens located below the step 44, in the direction of the optical axis O.

[0110] In the case where the input microlenses 20 forming the step 44 are offset from each other so that the input microlens located above the step 44 is placed in front of the input microlens located below the step 44, in the direction of the optical axis O, the description is similar with an up-down symmetry of Figure 2. For example, positive values ​​become negative values ​​and vice versa, and lower limits become upper limits and vice versa.

[0111] It should be noted that when the microlens matrix device is formed from injectable plastic material, it can be demolded along an axis which forms a non-zero angle with the optical axis O. The clearance angle must then have a sufficient value relative to this inclined demolding axis, the orientation of the step 44 relative to the reference direction R remaining in accordance with the angular range defined above. However, the microlens matrix device can also be manufactured by methods other than injection, in particular methods not requiring the presence of a clearance relative to a demolding angle. In this case, the range of orientation of the step 44 relative to the reference direction R as described above remains valid.The present invention thus proposes a light module which comprises a microlens matrix device within which steps are arranged between adjacent input microlenses to give a curved profile to the microlens matrix device, said steps being configured to have a predefined angle responding equally well to optical problems, because the inclination of the steps makes it possible to limit stray light rays, as to manufacturing problems linked to the demolding of the microlens matrix device, the angle of the steps allowing demolding of the microlens matrix device without difficulty.

[0112] The present invention cannot, however, be limited to the means and configurations described and illustrated here and it also extends to any equivalent means and configuration as well as to any technically effective combination of such means.

Claims

CLAIMS 1. Light module (1) for a motor vehicle configured for the projection of at least one light beam along an optical axis (O) of said light module (1), the light module (1) comprising at least one light source (2), a collimator (4) and a microlens matrix device (6), the light source (2) being configured to emit light rays towards the microlens matrix device (6) through the collimator (4), the microlens matrix device (6) comprising a main input face (16) intended to receive incident light rays (10) coming from the light source (2) and having passed through the collimator (4), a main output face (18) opposite the main input face (16), and a plurality of light circulation conduits (14) comprising an input microlens (20) and an output microlens (22),each light circulation conduit (14) being delimited by an input face (24) participating in forming the main input face (16) and an output face (26) participating in forming the main output face (18), the light module (1) being configured so that each incident light ray (10) received by the main input face (16) is included in an angular range of incidence (12) and so that each light ray refracted through the main input face (16) to propagate within a light circulation channel in the direction of the main output face (18) is included in an angular range of refraction (30), at least some of the input microlenses (20) being offset relative to the other input microlenses so as to form steps (44) between two adjacent input microlenses (20),at least one step (44) being configured so that an angle (a) between the step (44) and a reference direction (R) of the light module (1) is between a first terminal (36) delimiting the angular range of incidence (12) relative to this reference direction (R) and a second terminal (42) delimiting the angular range of refraction (30) relative to this reference direction (R)., 2. Light module (1) according to the preceding claim, in which the first terminal (36) corresponds to an incident light ray (32, 34) of the angular range of incidence (12) closest to the reference direction (R) and the second terminal (42) corresponds to a refracted light ray (38, 40) of the angular range of refraction (30) closest to the reference direction (R).

3. Light module (1) according to any one of the preceding claims, wherein the inlet faces (24) of the light circulation conduits (14) are offset from each other in a direction parallel to the reference direction (R).

4. Light module (1) according to the preceding claim, in which the entry faces (24) of the light circulation conduits (14) are offset according to a monotonic function.

5. Light module (1) according to any one of the preceding claims, wherein the inlet faces (24) of the light circulation conduits (14) are respectively arranged symmetrically around an axis parallel to the reference direction (R).

6. Light module (1) according to any one of the preceding claims, in which at least some of the steps which are arranged between input faces of the microlens matrix device intended to receive incident rays coming from the same light source are parallel to other steps.

7. Light module (1) according to any one of the preceding claims, in which at least some of the light circulation conduits (14) have thicknesses (E) different from that of the other light circulation conduits, the thickness (E) of a light circulation conduit being measured between an inlet face (24) and an outlet face (26) of this conduit.

8. Light module (1) according to any one of the preceding claims, comprising an additional light source (8), the incident rays (10) coming from the light source (2) and the incident rays (10) coming from the additional light source (8) having, at the exit of the collimator (4), different angles of incidence.

9. Light module (1) according to the preceding claim, comprising a partition (13) arranged between the incident rays (10) coming from the light source (2) and the incident rays (10) coming from the additional light source (8).

10. Light module (1) according to any one of claims 8 or 9, in which at least some of the inlet faces (24) of the light circulation conduits (14) receiving the incident rays (10) from the additional light source (8) are offset relative to the other input faces in a direction parallel to the reference direction (R), these input faces (24) being offset according to a monotonic function, the monotonic function followed by the input faces (24) receiving the incident rays (10) from the light source (2) and the monotonic function followed by the input faces (24) receiving the incident rays (10) from the additional light source (8) being different functions.

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