Lighting device comprising a micro-lens array device

Abstract

A lighting device (1) comprising a micro-lens array device (2), with at least one input micro-lens array (21) and one output micro-lens array (22), the device being characterized in that at least one light passage channel (5) arranged along the main optical axis (10) is formed continuously by an input micro-lens (20) and at least one output micro-lens (24, 241, 242), the input micro-lens (20) being configured to cause the beams of substantially parallel rays coming from the collimator (3) to converge in a convergence zone on the output face of the at least one output micro-lens (24, 241, 242) associated with this light passage channel, the at least one output micro-lens (24, 241, 242) being configured to image the input face of the input micro-lens (20) associated with this light passage channel (5).

Description

[0001] DESCRIPTION

[0002] Title of the invention: Luminous device comprising a microlens matrix device

[0003] The present invention relates to the field of lighting devices, in particular suitable for equipping a motor vehicle.

[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, including daytime running light functions or direction indicator light functions.

[0005] Headlights must be increasingly compact and it may be sought to have within these headlights a single light module capable of generating several light functions and in particular a lighting function and a signaling function. In this context, it is sought to emit light beams specific to each of the light functions generated by the module through the same lighting surface. In other words, in a search for a visual identity for the lighting of a vehicle, it is desired that an observer outside the vehicle sees the same illuminated surface whether it is a lighting function or a signaling function which is provided by the headlight.

[0006] Furthermore, motor vehicle lighting devices can also be used to perform interior lighting functions and / or to perform road marking functions, in particular aimed at projecting pictograms onto the roadway in the immediate vicinity of the vehicle.

[0007] In some applications, light rays emitted by a light source are directed into a microlens array (MLA) to shape a beam to perform a light function.

[0008] The matrix device comprises an array of input microlenses, an array of output microlenses and 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] The mask is made in particular by a glass plate on which an opaque perforated coating is placed, this glass plate forming a support for two optical blocks respectively forming the input microlens matrix and the output microlens matrix. In particular, the microlens matrices can be molded and hardened on the glass plate.

[0010] It is therefore appropriate to provide a lighting device which offers the same optical advantages as those of a microlens matrix, and in particular the possibility of giving the functional illuminating surface a great deal of freedom of form, and therefore freedom of style for the projector equipped with the matrix device, by means of discretization by the unit of surface of the input and output microlenses, while proposing a lighting device which is simple to produce and which allows the production, where appropriate, of two or more lighting functions on the same illuminating surface.

[0011] In this context, the present invention provides a light device comprising at least one light emitting means, a collimator and a microlens matrix device, the light emitting means being configured to emit light rays towards the matrix device via the collimator, the matrix device comprising at least one input microlens matrix having an input face facing the outside of the matrix device opposite the collimator, an output microlens matrix having an output face facing the outside of the matrix device opposite the input microlens matrix, and a main optical axis intersecting the two microlens matrices, the device being remarkable in that at least one light circulation channel arranged along the main optical axis is formed continuously by an input microlens and at least one output microlens,the input microlens being configured to converge the substantially parallel beams of rays coming from the collimator into a convergence zone on the output face of the at least one output microlens associated with this light circulation channel, the at least one output microlens being configured to image the input face of the input microlens associated with this light circulation channel.,

[0012] The light-emitting means may comprise one or more semiconductor photoemissive elements, which may for example be light-emitting diodes respectively.

[0013] Each input and output microlens has a domed surface, facing outward from the array device, and the thickness of material extending from the domed surface to the other input microlens.

[0014] The channels are defined as a strip of the material of the matrix device formed by an input microlens and at least one output microlens arranged opposite the input microlens if the principal optical axis is considered, and there is no structural element within the matrix device, such as a partition for example, to generate a physical delimitation between two neighboring channels.

[0015] The matrix device comprises a single input microlens for a given light circulation channel. According to the embodiments, an input microlens is associated, in a given light circulation channel, with an output microlens or with a plurality of output microlenses.

[0016] The association of an input microlens with a plurality of output microlenses makes it possible, in particular when there is only one light source, to improve the lit appearance of the microlens matrix. It is understood that thus, whatever the angle from which an observer observes the light device, the whole or the majority of the microlens matrix device appears lit, that is to say that the lit microlenses in a given observation direction are distributed over the whole of the microlens matrix device.

[0017] Due to the convergence of rays from an input microlens to an output microlens, the light can be propagated fully to the output microlens array, from light circulation channel to light circulation channel, which allows the efficient realization of a light function. In other words, the output microlens makes it possible to generate a beam portion that has the same contour as the associated input microlens in the same light circulation channel. The light is propagated fully because for a given light circulation channel, the size of the output microlens(es) is chosen so that this size is greater than or equal to the size of the image of the light source formed by the action of the collimator and the input microlens on the output microlens.

[0018] In order to avoid having an unlit area on the input face of the matrix device, with the exception, where appropriate, of opaque elements added to this input face to clearly distinguish the boundary between two neighboring input microlenses, it is understood that if an input microlens is given a smaller dimension than the average of this dimension for all the microlenses, this implies a correspondingly larger dimension for one of the neighboring microlenses, in order to compensate. It follows from this, in certain cases, that one or more channels within the matrix device are theoretically delimited by boundaries linking the edges of an input microlens to the edges of the associated output microlens(es) which are not parallel to the main optical axis.

[0019] The collimator is configured to redirect the rays passing through it so as to form at the output a beam of rays essentially parallel to each other and thus to direct these light rays homogeneously towards the microlenses of the input microlens matrix. Mention is made of a beam of essentially parallel rays to the extent that the dimension of the light source, which is wider than a theoretical point, may imply a slight angle between the rays deflected by the collimator. By "continuously", it is understood that there is a continuity of material from one face to the other, so that the microlens matrix can be obtained in one injection step, without it being necessary to produce it in two parts arranged on either side of a glass plate configured to form a mask in the thickness of the matrix device.

[0020] By "converge", we mean that we aim to ensure that all the rays passing through the input microlens pass through the output microlens, so as not to lose luminous efficiency.

[0021] By "imaging", we understand that the output microlens is configured to present an object focal length as close as possible to the entrance face of the input microlens and to consequently project to infinity the rays passing through this input microlens.

[0022] Whether for convergence or focusing, it should be understood that throughout the description, a margin of error is provided for the location of the object or image foci of the different optical elements formed by the microlenses in particular.

[0023] Each input microlens is configured so that the entire beam converges on the output face of the output microlens arranged at the other end of the flow channel, but the convergence point can be before or after the output face.

[0024] On the other hand, it is important that the focal length of the output microlens is positioned as close as possible to the input microlens.

[0025] According to a characteristic of the invention, for a given circulation channel, the focal length of the output microlens is closer to the input face of the input microlens than the focal length of this input microlens is to the output face of the output microlens.

[0026] The input microlens array and the output microlens array are composed of microlenses whose dimensions are of the order of a millimeter, between 0.025 mm and 10 mm. More specifically, the microlenses 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 microlenses, and thus to limit the mass of the part. Furthermore, the microlenses all have a size, in diameter, height and / or width, in front view, greater than or equal to 0.1 mm for the output microlenses and 0.5 mm for the input microlenses. This allows the lenses to be small enough not to be distinguished at the usual observation distance, while allowing the optical device to be manufactured by a simple injection process to implement.

[0027] According to an optional feature of the invention, the input microlenses have an aspect ratio corresponding in a vertical and transverse plane to a horizontally elongated rectangle. The ratio between the largest dimension, i.e. the transverse dimension, and the smallest dimension, i.e. the vertical dimension, is at least 2 to 1. As a non-limiting example of the invention, this ratio may more particularly be of the order of 3 or 4 to 1, in particular when it is a question of projecting onto the road a cut-off beam of the dipped beam type.

[0028] According to various optional features of the invention, to be considered alone or in combination, the largest dimension, i.e. the transverse dimension, is between 0.1 mm and 10 mm and the smallest dimension, i.e. the vertical dimension, is between 0.025 mm and 2.5 mm. More particularly, the input microlenses may have a vertical dimension of the order of 0.01 mm and the output microlenses may have a vertical dimension of the order of 0.25 mm.

[0029] According to an optional feature of the invention, the at least one output microlens has an off-center cutout.

[0030] By off-center cutting, it is intended to protect in particular the fact that the at least one output microlens is a portion of lens which is cut to the dimensions of the light circulation channel on the basis of an aspherical lens with an optical axis which is substantially parallel to the general optical axis of the optical system but offset from the center of the light circulation channel and a portion of spherical lens.

[0031] According to an optional feature of the invention, within a light circulation channel, the at least one output microlens is focused on an edge of the input face of the input microlens.

[0032] This is implemented in particular for traffic channels intended to be crossed by light rays participating in forming a lighting function, and in particular a dipped headlight function for which it is desired to have a clear cut-off of the beam, the cut-off of the beam then being achieved by said border delimiting the opening on which the object focus evoked is arranged.

[0033] The output microlens is configured to have an optical axis aligned vertically with said edge, i.e. the lower edge, of the input microlens

[0034] It is further configured so that the optical axis intersects the entrance face of the entrance microlens in an area around a specific point on this edge, whether the center of the edge or a projection provided on this edge.

[0035] The edge in question of the entrance face is a lower edge when it comes to producing a portion of the dipped beam, because the cutting of the projected beam must be clear in its upper part.

[0036] Alternatively, the edge in question of the entry face is an upper edge when it is a question of producing an additional portion of the main beam, which must complement a lower portion of the main beam, or else be a lateral edge when it is a question of producing a portion of the matrix lighting beam, the beam being divided into juxtaposed lateral bands which can be selectively activated.

[0037] According to an optional characteristic of the invention, the edge of the entrance face of the entrance microlens on which the at least one exit microlens is focused has a projection.

[0038] According to an optional feature of the invention, the at least one light circulation channel is arranged along the main optical axis by being formed on one side by a single input microlens and on the other side by a plurality of adjacent output microlenses.

[0039] According to an optional feature of the invention, adjacent output microlenses may extend in offset elongation planes, with a step that is formed from one output microlens to the other.

[0040] According to an optional feature of the invention, at least one average dimension of an input microlens participating in delimiting a light circulation channel is a multiple of a corresponding average dimension of the output microlenses participating in delimiting this light circulation channel. By average dimension, it is understood that a particular dimension of the input microlens or the output microlens is considered, whether it is a height, a width, a diagonal or an area, and that an average value of this particular dimension is calculated from one longitudinal end to the opposite longitudinal end.For example, when a light circulation channel extends between an input microlens and two output microlenses, the average area of ​​the input microlens, i.e. the average of the areas projected in the vertical and transverse elongation plane, is equal to the sum of the corresponding dimensions, here the areas, projected in the same plane, of the two adjacent output microlenses.

[0041] According to an optional characteristic of the invention, the output microlenses of the same light circulation channel are juxtaposed along a vertical direction and the projection is formed on a vertical end edge of the entry face, the projection being substantially centered on this edge in a transverse direction perpendicular to the vertical direction.

[0042] According to an optional feature of the invention, the output microlenses of the same light circulation channel are juxtaposed along a transverse direction and the projection is formed on a vertical end edge of the entrance face, the projection being positioned on this edge by being transversely off-centered to be opposite the output microlens configured to image the edge of the entrance microlens. The optical axis of the output microlens can be centered on the projection, but it can also be offset, in particular to find a compromise between the centering on the projection necessary for better sharpness of the cutoff in the projected beam and the opening on the outside of the projected beam.

[0043] According to an optional feature of the invention, the output microlenses of the same light circulation channel are configured to have object foci positioned differently on the input face of the input microlens of this light circulation channel. This feature is advantageous in particular for more easily producing different parts of the beam of the light function.

[0044] According to an optional feature of the invention, one of the output microlenses is focused on the edge of the input microlens and in which the other output microlens is focused substantially on the center of the input face of the input microlens. In this way, it is possible in each light circulation channel to image the input face with sharpness in different areas.

[0045] By substantially in the center, it should be understood that this object focus is arranged far from an edge delimiting the second 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 second opening. This is notably implemented for traffic channels intended to be crossed by light rays participating in forming a signaling function.

[0046] When a first light source is activated, the light rays are made convergent by each input microlens within their associated circulation channel onto a first output microlens present in this channel. When the second light source is activated, the light rays are made convergent by each input microlens within their associated circulation channel, onto a second output microlens present in this channel. Each of the output microlenses present in the same channel is focused on different areas of the input microlens associated with this channel. The second output microlenses are offset relative to the first input microlenses according to the direction of offset of the light sources relative to each other.It is notable that the light rays are capable of being directed after passing through an input microlens, such that the light rays can propagate entirely in the direction of one of the output microlenses. There are thus no or few light rays blocked within the matrix device and no loss of light intensity, in particular for the implementation of a signaling function.

[0047] According to an optional feature of the invention, only one output microlens of the plurality of output microlenses of the same light circulation channel is configured to have an object focus on the input face of the input microlens of this light circulation channel. In other words, at least one of the output microlenses is not focused on the input face, so that this output microlens does not generate a sharp image of the input lens. This may in particular be the case because the focusing plane of this output microlens is offset from the plane of the input face of the input microlens in a longitudinal direction, or because this output microlens has no focusing plane.

[0048] According to an optional feature of the invention, at least two of the microlenses have different focal lengths, from one light circulation channel to another.

[0049] In other words, for a first light circulation channel, the microlenses, and in particular the output microlens(es), have focal length values ​​which are different from the focal length values ​​of the microlenses, and in particular the output microlens(es), of a second light circulation channel.

[0050] According to an optional feature of the invention, at least two of the light circulation channels have a longitudinal dimension that varies from one light circulation channel to another. This makes it possible in particular to configure the output face in such a way that it follows a curve adapted to the installation and / or the style of the lighting device. The variation in the longitudinal dimension, from one channel to an adjacent channel, along the matrix device, may be linear, or present changes, for example so as to be faster on one side of the matrix device compared to the opposite side.

[0051] According to an optional feature of the invention, the output face which is associated with a first light circulation channel longer than a second light circulation channel is flatter than the output face associated with this second light circulation channel. The fact that one output face is flatter than another is determined more particularly by the curvature of these output faces. A so-called flatter output face has a smaller curvature.

[0052] According to an optional characteristic of the invention, the dimension of a projection within an input microlens varies as a function of the longitudinal dimension of the light circulation channel associated with this input microlens and / or the focal length of the output microlens configured to image the input face of said input microlens.

[0053] According to an optional feature of the invention, the optical axis of at least one output microlens is offset relative to a central longitudinal axis of the associated light circulation channel.

[0054] According to an optional feature of the invention, the optical axis of an output microlens can be positioned so that it intersects the input face of the input microlens with a transverse offset relative to the projection formed on the edge of the input face of this microlens.

[0055] According to an optional feature of the invention, the position of a projection formed on an edge of the input microlens relative to a central longitudinal axis of the associated light circulation channel is different from one input microlens to an adjacent input microlens.

[0056] According to an optional feature of the invention, the channels are arranged side by side so as to form transverse rows which overlap one another along a vertical dimension, and the channels of one row are transversely offset relative to the channels of an adjacent row. According to an optional feature of the invention, the input microlens array and the output microlens array form a single-piece matrix device.

[0057] In other words, the input and output microlenses are made of one material and form a single-piece assembly. The matrix device does not include a partially opaque mask in the thickness between the two microlens matrices and on which each of the two matrices is attached. One longitudinal end of the input microlens matrix is ​​directly pressed against one longitudinal end of the output microlens matrix, without any material discontinuity.

[0058] According to an optional feature of the invention, the two microlens matrices are produced in a single injection operation.

[0059] According to an optional feature of the invention, the light device comprises opaque elements arranged against the input face of the matrix device so as to overlap an edge common to two neighboring input microlenses. For example, an opaque plastic may be bonded to the face of the matrix device opposite the collimator, to form clear demarcations between the input faces of each input microlens. This optical plastic may also be etched, printed or overmolded onto the input face of the matrix device. It is notable that in all cases, these opaque elements are not present in the thickness of the matrix device.

[0060] According to an optional characteristic of the invention, the light emission means comprise a plurality of light sources, in particular selectively addressable, the collimator being common to the plurality of light sources and configured to conform the light rays emitted by each light source into a beam of substantially parallel rays directed towards the matrix device, with an angle of inclination of the beam of substantially parallel rays relative to the optical axis which is different depending on the activated light source, the light device being remarkable in that it comprises a first light source the activation of which participates in generating a first light function and a second light source the activation of which participates in generating a second light function or an additional portion of the first light function,light rays emitted by the first light source being made convergent by the input microlens of a light circulation channel onto a first output microlens of this light circulation channel, light rays emitted by the second light source being made convergent by this same input microlens onto a second output microlens of this light circulation channel.,

[0061] The possibility of selectively addressing the light sources is advantageous in particular for the emission of several light functions. When the light sources participate in the generation of the same light function, they are advantageously addressable only simultaneously, which makes it possible to simplify the configuration of the control circuit of said light sources, but can also be selectively addressable, for example for a progressive switching on of said light function.

[0062] According to an optional characteristic of the invention, the second output microlenses associated with a light circulation channel have an optical axis whose relative position within the light circulation channel is distinct from the corresponding relative position of the optical axis of the first output microlenses associated with this light circulation channel.

[0063] Thus, providing an off-center exit microlens so that its center is aligned with the aperture or the edge of the aperture helps to appropriately deflect light rays.

[0064] The lighting device according to the invention makes it possible to have two lighting functions, including a daytime running light type signaling function, known by the acronym DRL for Day Running Light in English, and a dipped beam type lighting function. Alternatively, the lighting device could allow the realization of a daytime running light type signaling function and a high beam type lighting function, with the two output microlenses present in the same traffic channel which are both focused on the center of the associated input microlens. Also, and without this being exhaustive of the possibilities offered by the lighting device according to the invention, it would be possible to have a dipped beam type lighting function and a high beam type lighting function.

[0065] The light sources are said to be selectively addressable insofar as they can be activated independently of one another, by an electronic control device. For example, when one of the light sources is activated, the other or other light sources can be deactivated so that only one light source is capable of emitting light rays. Alternatively, to homogenize the lit appearance of the surface depending on the activation of the lights, it may be envisaged to leave lit a source associated with a specific function while another source is lit. In other words, in certain cases, at least some of the light sources, in particular all the light sources, can be lit simultaneously, which makes it possible to simultaneously generate the respectively associated light functions.When all sources are on at the same time, it is possible that some sources are on at varying levels of light intensity for example.

[0066] 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, or an additional portion of the first light function making it possible to generate by combining these two portions a specific light function. In both cases, the light participating in performing the light function exits an illumination surface formed by the output microlens matrix.

[0067] The matrix device according to the invention thus makes it possible to easily and precisely produce different lighting functions with the same lighting surface.

[0068] It should be noted that by participating in generating, it is understood that the light device according to the invention can be the only device allowing the production of the desired lighting or signaling beam or that the light beam generated by this light device can be combined with other light beams generated by other light devices to form said beam, whether or not these other light devices comply with the invention.

[0069] According to an optional feature of the invention, the first light source and the second light source are at a distance from each other, being distributed on either side of a defined plane, the first light source being closer to said defined plane than the second light source. The first source may, if necessary, be arranged partly on this defined plane. The defined plane considered is a plane substantially perpendicular to one and / or the other of the microlens matrices and it comprises the main optical axis of the light device. This defined plane may in particular be a median plane, if necessary a plane of symmetry, of the collimator.By distance from each other, it should be understood that the light sources are not in contact with each other and are sufficiently separated, for example of the order of 0.5 to 10 times the size of the light source, so that the rays can have a different inclination at the exit of the collimator depending on whether they are emitted by one or the other of the light sources.

[0070] According to an optional feature of the invention, the collimator is formed by one or more lenses, or by one or more mirrors. In particular, the lens(es) may be converging lenses.

[0071] According to an optional characteristic of the invention, the input microlenses and the output microlenses respectively have an external face, in particular curved, facing the outside of the matrix device, and the matrix device is configured to have an output surface, formed by the plurality of external faces of the output microlenses, which is inclined relative to a longitudinal direction along which the main optical axis of the light device extends.

[0072] The input microlens array and the output microlens array may remain in a vertical and transverse plane, perpendicular to a longitudinal direction along which the main optical axis of the light device extends, with light circulation channels remaining in this orientation parallel to the optical axis, and the external faces of the input microlenses are axially offset from each other, so as to form transverse rows axially offset from each other and thus staircase steps which create the tilting effect when viewing the screen as a whole.

[0073] The invention also relates to a light module for a motor vehicle, comprising a plurality of light devices respectively in accordance with the present description, each device forming a functional brick.

[0074] Each functional brick has its own light emission means, i.e. one that emits light rays towards the collimator associated with that functional brick. The collimators and matrix devices of each of these different functional bricks can be juxtaposed and made in one piece, these functional bricks not interacting with each other for the projection of the light beam(s) specific to them.

[0075] The invention also relates to a motor vehicle comprising at least one lighting device in accordance with the present description.

[0076] 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:

[0077] [Fig.l] represents a light device according to the present invention, making visible a light source, a collimator and a matrix device, comprising in particular a matrix of input microlenses and a matrix of output microlenses;

[0078] [Fig.2] represents a sectional view of a portion of the matrix device, with three light circulation channels, and a schematic ray trace to illustrate ray convergence and focusing characteristics;

[0079] [Fig.3] represents a perspective view of a part of the matrix device, making visible in particular projections formed on the input microlenses of the matrix device;

[0080] [Fig.4] represents three light circulation channels intended to be adjacent in the matrix device, with a projection formed in the input microlens of Y1 each channel having a different position from one channel to another, the image projected by the output microlens being illustrated at a distance from the light circulation channel;

[0081] [Fig.5] represents a superposition of the images projected by the three output microlenses to illustrate the interest of the shift in the position of the projections seen in figure 4;

[0082] [Fig.6] shows the input microlens array as seen from the collimator to illustrate the offset of the position of the bumps seen in Figure 4;

[0083] [Fig.7] shows a side view of the matrix device of Figure 1, with a ray trace, the matrix device having microlenses having different focal lengths;

[0084] [Fig.8] illustrates the different size of the images projected by the matrix device depending on the focal length of the microlenses of this matrix device;

[0085] [Fig.9] shows a variant of the input microlens array in a view similar to that of Fig. 4;

[0086] [Fig.10] represents a second embodiment of the invention comprising two light sources and a collimator common to these two light sources;

[0087] [Fig. 11] represents a first variant of implementation of the second embodiment of Figure 10;

[0088] [Fig.12] represents a second variant of implementation of the second embodiment of figure 10.

[0089] 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.

[0090] 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.

[0091] In the figures, elements common to several figures retain the same reference.

[0092] 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 12, with the longitudinal axis L corresponding to the general direction of propagation of the light rays 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 device, perpendicular to the longitudinal axis L. More particularly, the vertical axis V and the transverse axis T correspond respectively to the height and width of microlens faces as will be described in more detail below, these faces having a width dimension greater than that of the height.The choice of names for these axes does not limit the orientation that the lighting device can take, particularly when it is installed in a motor vehicle.

[0093] Figure 1 schematically illustrates a light device 1 comprising a matrix device 2 of microlenses, a collimator 3 and a light emission means 4.

[0094] The light emission means 4 generally comprises at least one light source. In the embodiment shown in Figure 1, only one light source is used but other embodiments, shown in particular in Figures 10 to 12, implement a plurality of light sources, here two light sources including a first light source 41 and a second light source 42. As will be mentioned later, the number of light sources can vary as long as the matrix device is configured accordingly. The number of light sources has in particular an effect on the number of light functions which can be implemented by the device according to the invention.

[0095] The lighting device 1 of Figure 1 allows the realization of a single lighting function. More particularly, the device is advantageous for the implementation of a dipped beam type lighting function, with a projection onto the road scene upstream of the vehicle of a beam with a higher cut-off making it possible not to dazzle other road users, but it could be implemented for the realization of other functions, such as a main beam type lighting function, without cut-off, a signaling function, an interior lighting function or even a road marking function consisting of a projection of pictograms.

[0096] The light device 1 has a main optical axis 10, the light device being configured to carry out the projection of a light beam to infinity with this optical axis as projection reference, here parallel to a longitudinal axis.

[0097] The at least one light source 4 is arranged on or in the vicinity of a defined plane comprising this main optical axis 10 of the light device.

[0098] The collimator 3 and the light emission means 4 are positioned relative to each other so that the light rays emitted by the light source(s) 41, 42 pass through the collimator 3. This collimator 3 is configured to capture light rays emitted by each of the light sources and to orient them essentially parallel to each other and to direct them towards the matrix device 2, and more specifically towards an input microlens matrix 21.

[0099] By "essentially parallel" we understand that the rays may have an angular offset linked to the size of the light source that generates them. In other words, in the embodiment with a light source, the collimator 3, which here has the shape of a converging lens, but which could alternatively be made up of several lenses and / or several mirrors for example, is configured to generate at the output, in the direction of the matrix device 2, a first beam of parallel rays visible in FIG. 7 in particular.

[0100] 11 It should be understood that when the light source is made active, the rays may have an angle of inclination relative to the main optical axis 10 of a first value, if the position of the light source is offset relative to a plane comprising this main optical axis. 11 It should also be understood that this collimator 3 is configured to generate at the output a beam of parallel rays, but completely different, that is to say with a different inclination, if the activated light source is changed. The collimator 3 is then able to generate at the output, in the direction of the matrix device 2, another beam of parallel rays when another light source is made active, the rays all or almost all having an angle of inclination relative to the main optical axis of another value, different from the first value, as will be explained below with reference to FIG. 10.

[0101] The microlens matrix device 2 comprises said input microlens matrix 21 and an output microlens matrix 22, each matrix having an external face, respectively an input face 210 for the input microlens matrix 21 and an output face 220 for the output microlens matrix 22, facing away from the external face of the other matrix.

[0102] In the illustrated example, each microlens matrix 21, 22 extends mainly along a vertical and transverse plane, perpendicular to a longitudinal direction L along which the main optical axis 10 of the light device 1 extends. Alternatively, the matrix 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 matrix device as a whole or by forming steps at the output face of the matrix device formed by the output face, that is to say the external face of the output microlens matrix.

[0103] The output face of the matrix device 2, i.e. the output face 220 of the matrix of output microlenses 22, forms a lighting surface of the lighting device 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 lighting functions capable of being performed by the lighting device.

[0104] The input microlens array 21 is formed from a plurality of input microlenses 20 juxtaposed next to each other, both in the vertical direction and in the transverse direction, as can be seen in FIG. 1. These input microlenses 20 each have a curved surface whose juxtaposition, if necessary with a longitudinal offset which generates a step from one curved surface to the other, forms the input face 210 of the input microlens array 21, and they each have a thickness of material extending between the curved surface and the output lens array 22 to be able to propagate the light from one to the other.

[0105] In accordance with the arrangement of the input microlens array 21, the output microlens array 22 is formed of a plurality of output microlenses 24 juxtaposed next to each other, both in the vertical direction and in the transverse direction as can be seen in FIG. 1.

[0106] These output microlenses 24 each have a curved surface whose juxtaposition, where appropriate with a longitudinal offset which generates a step from one curved surface to the other, forms the output face 220 of the matrix of output microlenses 22, that is to say the output face of the matrix device, and they each have a thickness of material extending between the matrix of input microlenses 21 and the curved surface to be able to propagate the light from one to the other.

[0107] Each microlens matrix, input or output, thus has an external face, facing away from the other matrix and formed by the plurality of external faces of the microlenses making up this matrix, and an internal volume, formed by the thickness of material which extends from the external face to the other matrix.

[0108] In this figure 1, a junction plane P between the input microlenses 20 and the output microlenses 24 has been represented in dotted lines, but it should be noted that this junction plane is indicative, the matrix device 2 extending according to the invention continuously between the matrix of input microlenses 21 and the matrix of output microlenses 22, without interposed mask.

[0109] The matrix device 2 according to the invention is configured to comprise within it light circulation channels 5, extending respectively, in a direction parallel to that of the main optical axis 10, between an input microlens 20 and at least one output microlens 24, where appropriate several adjacent output microlenses as will be described below, the number of adjacent output microlenses 24 participating in delimiting the same light circulation channel depending on the number of different light sources capable of being activated opposite the same collimator. In the example illustrated in FIGS. 10 to 12, where two light sources are provided, each light circulation channel 5 extends between an input microlens 20 and two adjacent output microlenses 24, among which a first input microlens 241 and a second output microlens 242 can be distinguished.

[0110] 11 It is notable in the figures schematically representing the matrix device that only the external face 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 to the other microlens arranged opposite along the main optical axis 10.

[0111] In Figure 1, the outer face of the input and output microlenses has different curvatures from one light circulation channel to another, and the lengths of the output microlens 24 is variable, so that a longer light circulation channel 5 implies a more flattened face. But it should be noted that this is given as an example and that this configuration is also different in the following figure.

[0112] According to the invention, the matrix device 2 is particular in that for a given light circulation channel 5, the output microlens 24 is focused on the input microlens 20 and the input microlens 20 converges the light rays onto the output microlens 24. More particularly, each input microlens 20 is configured within the matrix device 2 in such a way that it forms a converging lens whose image focus forms a convergence point Pc positioned in the vicinity of the output face of the output microlens 24 which is arranged directly opposite the input microlens 20 in the associated light circulation channel 5. The light rays coming from the collimator 3 and passing through an input microlens 20 converge towards this convergence point Pc in the vicinity of the output microlens in this light circulation channel.

[0113] By the vicinity, it should be understood that this convergence of the rays can be axially offset since almost all of the rays pass through the exit face 220 of the exit microlens 24 and remain in the circulation channel 5 dedicated to it. In other words, the convergence point Pc of the rays deflected by the entrance microlens can be on or before or after the exit face of the exit microlens, considering the longitudinal direction, since this offset is of a minimal value compared to the longitudinal elongation dimension of the light circulation channel, and for example at least less than 10% of this elongation dimension.

[0114] Furthermore, the convergence point Pc is substantially centered on the exit face of the exit microlens 24, if we consider a projection of this exit face in a plane perpendicular to the longitudinal direction.

[0115] In this way, the light rays shaped by the collimator 3 which are made to pass through an input microlens 20 propagate essentially in the light circulation channel 5 associated with this input microlens 20 and they emerge from the matrix device 2 essentially through one of the output microlenses 24 associated with this light circulation channel, in particular thanks to the convergence of rays on the output microlens 24 which is made by the input microlens 20.

[0116] In the illustrated example, the input microlenses 20 are identical to each other.

[0117] Each output microlens 24 is configured within the matrix device 2 such that it has an object focus F on the input microlens 20 associated with its light circulation channel 5. The light rays propagating within the matrix device 2 and passing through this object focus F are reoriented by the corresponding output microlens 24 into a light beam to be projected towards the outside of the vehicle to participate in forming a lighting beam on the road scene or a signaling beam.

[0118] In other words, the contour of an input microlens 20 is imaged by the output microlens 24 present in the same light circulation channel 5. This results in the need for a precise contour of the input microlenses 20 whose images, projected to infinity by their respective associated output microlens 24, are juxtaposed to form the overall beam of the light function. The input face of the matrix device is thus worked so that there is no continuity from one input microlens face to another.

[0119] This can in particular be implemented by the presence of sufficiently marked fillets from one edge of an input microlens 20 to an adjacent edge of a neighboring input microlens 20. The discontinuity from one input microlens to the other is a discontinuity in tangency, as shown in Figure 2, which comes from the fact that there are two converging input lenses with optical axes distinct from each other. This is reflected in particular by the presence of an angle. A slight axial, longitudinal offset may appear locally at the level of the projection, due to the cutting of the shape of the projection on a lens, when this is provided on an edge of an input microlens, but no axial offset is provided if the edges of the input microlenses do not have a projection.

[0120] Advantageously, in order to clearly mark the demarcation between the input faces, it may be envisaged to form a sealing coating on the input face of the matrix device 2, in particular by a deposit of opaque plastic material, it being understood that this coating cannot be considered as a mask of the prior art present in the thickness of the mask between the microlens matrices. This coating also makes it possible to limit stray rays, since it makes it possible to mask manufacturing irregularities on the sharp edges of the contour of the input microlenses, and / or it makes it possible to mask possible steps on the input face of the matrix device due to a contour cut with the projection shape. In the latter case, it is thus possible to avoid generating steps on the input face, which makes it possible to limit stray light within the light circulation channels.Such steps should be avoided on the input face, while they may be present on the output face at the output microlenses, in an area where the light converges to a point away from the edges.

[0121] As discussed, each output microlens 24 has an object focus F located on or in close proximity to the input microlens 20. More particularly, at least one output microlens 24, and each output microlens in this example of FIG. 1, has an object focus F located on an edge 200 delimiting the input face 210 of the input microlens 20, such that this edge forms a sharp cut-off edge in the projected image. In the case of application of a dipped beam type lighting function, the edge 200 of the input microlens 20 on which the corresponding output microlens 24 is focused is more particularly a lower edge of the input microlens 20 so that in the projected beam, it is the upper rays which exit parallel to the optical axis 11 of the output microlens 24, and here parallel to the main optical axis 10, and have greater sharpness than the other rays.In other words, by aligning the optical axis of an output microlens with a low edge of the corresponding input microlens, we ensure that the high edges of the images are projected to infinity, so that it is also thanks to this alignment of the optical axis with a precise zone of the input microlens, and in particular here on an edge, that the high cut-off of the overall projected beam remains clear.

[0122] It is thus possible to achieve a clean cut-off that complies with the standards imposed for producing a cut-off lighting beam. In contrast, as will be described below, the lighting device is configured to have blurring means, aimed at misaligning the bottom of the images projected by each output microlens with respect to infinity, in order to create a blurred edge, by gently decreasing the light intensity.

[0123] Of course, if the edge of the input microlens on which the output microlens is focused is a lateral edge or an upper edge, it is understood that it is consequently a lateral edge or a lower edge of the projected beam which is particularly sharp. This can be particularly interesting in the case of producing a matrix lighting function, with juxtaposed vertical strips which form the beam and which can be switched on and off selectively, or in the case of producing a light beam of high beams, with an upper part of the beam which is projected in a manner complementary to the projection of a lower part of the beam.

[0124] In projection in a plane perpendicular to the main optical axis 10, the light circulation channels 5 all have a size, in diameter, height and / or width, in front view, less than or equal to 10 mm and greater than or equal to 0.1 mm, and it should be noted that the shape of the input and output microlenses should be considered accordingly.

[0125] The input microlenses advantageously have an aspect ratio corresponding in a vertical and transverse plane to a horizontally elongated rectangle. The ratio between the largest transverse dimension and the smallest vertical dimension is determined to correspond to the dimensions of the overall beam to be projected onto the road scene, and may in particular be at least 2 to 1, and more particularly of the order of 3 or 4 to 1 when it is a question of projecting onto the road a cut-off beam of the dipped beam type.

[0126] As will be described in more detail below, the output microlenses 24 may have a different configuration depending on the light circulation channel 5 in which they are arranged. In particular, certain output microlenses 24 may have, relative to the light circulation channel specific to them and to the light function that they must participate in generating, a symmetrical or asymmetrical configuration, or more particularly centered or off-centered, with an optical axis of the output microlens which is coincident with or offset relative to a median axis of the associated light circulation channel.

[0127] Figure 2 illustrates in particular in detail the essential characteristics of the invention making it possible to achieve a luminous function without a mask within the matrix device while having optimal luminous efficiency of the ZI system, namely the combination of a convergence of output microlenses and an appropriate focusing of output microlenses.

[0128] 11 It should be noted that this figure 2 illustrates a slightly different embodiment from that of figure 1, with output microlenses 24 of the same size, and therefore a step from one output microlens 24 to the other, but this embodiment nevertheless presents the same concept as what has been previously described at the level of the ray tracings, their convergence and their focusing.

[0129] Each output microlens 24 has an output face whose shape is a portion of a sphere whose optical axis 11 is substantially parallel to the main optical axis 10, here parallel to the longitudinal axis L, of the device as a whole. In the example illustrated, each output microlens is an aspherical lens, of the "Descartes oval" type, that is to say a stigmatic lens imaging an object in the material. Of course, each output microlens could have another shape. The cutting of the portion of the sphere, from one edge to the other of the corresponding light circulation channel 5, is such that the optical axis 11 of the output microlens 24 is aligned with a precise point of the input microlens 20 at the other end of the light circulation channel 5 and more particularly with a precise point of the lower edge 200 of this input microlens 20 as will be described below.

[0130] This results in a lower end 240 of an output microlens 24 which is offset axially, or longitudinally, relative to an upper end 245 of this output microlens 24, and this results in the presence of return edges 25 between two adjacent output microlenses 24, extending in a longitudinal and transverse plane arranged between the neighboring vertical ends of these two adjacent output microlenses 24.

[0131] This figure 2 illustrates a portion of the matrix device 2 with four sets of input microlenses and output microlenses, forming two by two longitudinally between them a circulation channel 5, shown in dotted lines in the figure.

[0132] The rays are illustrated with double arrows to distinguish them from the construction lines of the microlenses. Solid lines represent the actual rays which successively pass through the collimator (not visible here) and arrive essentially parallel to the input microlens. These rays are deflected by the input microlens 20 towards a convergence point Pc provided in the vicinity of the exit face 220 of the output microlens 24. In this way, it is ensured that almost all of the rays remain in the light circulation channel 5 associated with the input microlens 20 and the luminous efficiency is increased.

[0133] Here, the view is a sectional view in a vertical and longitudinal plane, and the point of convergence is substantially halfway up the output microlens. It should be understood that in a transverse and longitudinal sectional plane, the point of convergence is substantially halfway up the width of the output microlens. Furthermore, it should be understood that only the rays coming from a source point have been represented here, but that since the light source has a certain size, there will be a convergence spot on the output microlens instead of a point, and that it is this convergence spot, which will be assimilated to a point in the rest of the description to simplify reading, that we seek to center on the output microlens so that all the rays pass through the correct output microlens.

[0134] In the illustrated example, the convergence point Pc is slightly after, if we consider the longitudinal direction, the output microlens 24, that is to say slightly outside the microlens array, in particular to illustrate that by the notion of "convergence in the vicinity of", we aim to cover both a convergence point on the output face and slightly before or after.

[0135] The axial offset of the convergence point Pc relative to the exit face 220 may in particular be a few millimeters without this preventing the luminous efficiency previously mentioned. The greater the thickness of the exit microlens 24, that is to say its axial dimension, the closer the convergence point Pc must be to the exit face 220 of this exit microlens 24.

[0136] The hatched lines illustrate the focusing characteristic of the output microlenses, which are here focused on an edge 200 of the input face 210 of the corresponding input microlens 20. Each of the rays previously passing through this edge 200, here the lower edge of the input microlens, emerges parallel to the optical axis 11 of the output microlens 24.

[0137] Of course, the rays passing through this edge 200 are intended to converge towards the point of convergence Pc as explained previously. But it should be noted that in practice, rays passing through this edge 200 can be spread around the point of convergence Pc, forming a spot on the exit face around this point, in particular due to the geometric dimension of the light emission means, which cannot be infinitely small. However, it is notable that each of these rays passing through this edge emerges in all cases substantially parallel to the optical axis 11 of the exit microlens. The edge 200 of the entry microlens 20 on which the exit microlens 24 is focused is thus particularly sharp in the projected image, the optical axis 11 of each exit microlens being substantially parallel to the main optical axis 10.

[0138] In Figure 3, the concept as just mentioned is represented in the case of a dipped beam function, that is to say with a lighting function with an upper beam cut-off so as not to dazzle other road users, with a detail of a matrix device illustrating here four juxtaposed rows of two adjacent light circulation channels. Of course, the characteristics which will be described here can be reflected on the adjacent light circulation channels on the entire matrix device.

[0139] The output microlenses 24 here have a shape similar to that illustrated in FIG. 2, with each output microlens 24 being formed by a cutout of an aspherical lens with an optical axis 11 which is off-center with respect to the median axis of the light circulation channel 5, and with return edges 25 arranged between the neighboring vertical ends of two adjacent output microlenses 24.

[0140] The overall beam 100 to be projected to perform the dipped headlight function must have a clear upper cut-off, so as not to dazzle other road users, and this clear cut-off typically has a step 101 making it possible to increase the height of the beam projected on the right side of the beam, or on the left side when the vehicle concerned is intended for driving on the left side of the road.

[0141] As mentioned, the overall beam 100 projected onto the road using the device of the invention is a superposition of images of the input microlenses. More particularly, the step 101 in the overall projected beam is formed by the superposition of images, projected by each output microlens, of a projection 201 made on each lower edge 200 of an input microlens 20.

[0142] The projection 201 comprises in particular an inclined plane which generates a difference in level between a first lateral portion 20a of the entrance microlens and a second lateral portion 20b of this entrance microlens. The second lateral portion 20b extends longitudinally only locally, the remainder of the light circulation channel being formed in the continuity of this first lateral portion 20a.

[0143] Figure 3 shows in particular that the second lateral portion 20b formed by the projection 201 of a first light circulation channel 5a encroaches into the volume dedicated to a second light circulation channel 5b directly arranged under the first light circulation channel 5a.

[0144] In this way, it being understood that the image projected onto the road by the light device is the inverse of the shape of the input microlens that one seeks to image, the image of the input microlens 20 projected by this second light circulation channel 5b has a step 101 in the upper part, due to the presence of the projection 201 formed on the lower edge 200 of the input microlens 20 of this circulation channel, but also in the lower part, due to the presence of the projection imposed by that formed in the adjacent circulation channel.

[0145] In the context of a global beam 100 projected onto the road which is the superposition of all the images projected by the output microlenses, the superposition of an image with an unwanted jump in the lower part of the beam can generate an annoying perception for the driver, even if this part of the beam is more blurred than the upper part of the beam.

[0146] Means can advantageously be implemented to prevent the bottom of the dipped beam from having a level visible to the driver. A first means of managing this is to modify the dimension of one input face of the input microlens 20 relative to another, so that the dimension of the projected image is different. The dimension of the image projected by each output microlens 24 is thus different from one image to another and the superposition of these images generates in the overall projected beam 100 edges of the beam that are more blurred because they are less intense, due to the fact that fewer images are superimposed in these beam edge areas.The optical axis 11 of each output microlens 24 being always aligned with the lower edge 200 of the corresponding input microlens 20 and in particular with the projection 201 formed on this lower edge, the dimension of the step 101 in the overall projected image 100 resulting from the superposition of all the images remains the same and this step 101 remains clear.

[0147] Other means of blurring the bottom of the beam can also be implemented, where appropriate combined with each other and / or with the means just mentioned.

[0148] A first means of blurring is illustrated in Figure 4, in which three circulation channels arranged one above the other in the matrix have been shown in top view and next to each other. Of course, what will be described for three channels arranged successively could be applied to more channels.

[0149] This first blurring means consists of a positioning of the projection 201 of an input microlens, relative to the center of the corresponding light circulation channel 5, which differs from one input microlens 20 to another, and in a specific shape of output microlens 24 associated with this light circulation channel.

[0150] This specific shape is notably due to the fact that the optical axis 11 specific to the output microlens 24 is aligned with the projection 201 formed in the corresponding input microlens 20 to ensure that the image thereof is well positioned in the direction of the main optical axis. The output microlens 24 keeps a partially spherical shape with the optical axis 11 which forms a diameter of the sphere and the portion of the sphere which is formed by a cutout of the sphere in the volume formed by the light circulation channel 5 specific to this output microlens 24.

[0151] 11 results from this, as visible in FIG. 4, a first light circulation channel 5a in which the projection 201a is in a first position, laterally offset in a first direction SI by a first distance relative to the center of the light circulation channel, a second light circulation channel 5b in which the projection 201b is in a second position, laterally offset in a second direction S2 by a second distance relative to the center of the light circulation channel, and a third light circulation channel 5c in which the projection 201c is in a third position, laterally offset in the first direction SI by a third distance relative to the center of the light circulation channel.

[0152] For each of these channels, the rays passing through the lateral ends of the input microlens 20 of this channel and the ray passing through the projection 201, coincident with the optical axis 11, are represented. These three rays converge on the point of convergence Pc in the vicinity of the exit face 220 of the output microlens 24, this point of convergence Pc being located on the optical axis 11 specific to the output microlens in the light circulation channel, namely opposite the position of the projection. 11 As a result, at a given distance from the vehicle, the image of the projection 201a, 201b, 201c in the upper part of the projected image, here shown diagrammatically on the right of the figure, forms a clear step 101a, 101b, 101c positioned on the main optical axis 10 of the matrix device, the superposition of which in the overall projected beam 100 makes it possible to generate a clear image of a step 101, but the lateral terminals of the beam are different from one image to another.

[0153] Furthermore, it should be noted that laterally shifting the projection 201 on the lower edge 200 of an input microlens has the effect of laterally shifting the projection on the upper edge of the input microlens arranged under the latter. This is particularly visible in Figure 5, which is a front view of the matrix device seen from the collimator. For each light circulation channel 5, the axial offset Dx between the optical axis 11 of the output microlens and the projection that it is desired to attenuate in the lower portion of the overall projected beam, that is to say the projection present in the upper edge of the input microlens, differs from one light circulation channel.11 This results in the image of the overall beam projected onto the road, visible in Figure 6, a superposition of the images in which several steps are visible at the bottom of the beam, but with a lower intensity which makes them not annoying for the driver.

[0154] Figures 7 and 8 illustrate a second means of blurring the bottom of the beam.

[0155] This second blurring means consists of a modification of the focal length, that is to say a modification of the distance between the focal point, or object focus, F and the exit face 220 of an exit microlens 24, from one exit microlens to the other. This implies a modification of the length of the exit microlens 24 since each exit microlens remains, in accordance with the invention, focused on the entry microlens associated with it in the light circulation channel, and more particularly here on an edge 200 of this entry microlens 20.

[0156] In Figure 7, in accordance with what was done in Figure 1, a junction plane P between the input microlenses 20 and the output microlenses 24 has been illustrated, in particular to illustrate the variation in the lengths of one output microlens relative to the other, but it should be recalled that the matrix device 2 extends according to the invention continuously between the matrix of input microlenses 21 and the matrix of output microlenses 22, without an interposed mask.

[0157] In the illustrated example, the length of the output microlenses 24 increases progressively from one vertical end to the other of the matrix device 2, so that the design of the matrix device of FIG. 1 is found here, but it should be noted that the goal would be achieved in the same way with a more random distribution of the large and small lengths of the output microlenses.

[0158] Increasing the focal length of the output microlens 24 makes it possible to maintain a central and sharp position of the point on which the output microlens is focused, i.e. the area of ​​the projection 201, but it has the effect of reducing the size of the projected image. Figure 8 illustrates the impact of the focal length value on the size of the projected image. In the case of a small focal length Fp, of the order of one to two times the largest dimension of the input microlens entrance face, the image projected by the corresponding light circulation channel is larger than in the case of a large focal length Fg, of the order of at least ten times the dimension of the input microlens entrance face.In order to ensure that the step formed in the projected overall beam image is sharp, it may be advantageous, as illustrated in this figure 8, to provide a projection 201 in the lower edge 200 of an input microlens 20 whose size is a function of the length of the corresponding light circulation channel 5, the projection being larger from one channel to the other when the focal length of the output microlens is larger, and therefore the projected image correspondingly smaller.

[0159] Figure 9 illustrates a third means of blurring the bottom of the beam.

[0160] This figure illustrates a viewing angle similar to that of Figure 5, with the matrix device 2 seen from the front from the collimator 3. This third means consists of providing a lateral offset of the light circulation channels 5 from one row to the other, with the position of the projections 201 remaining centered on the associated light circulation channel. Having the light circulation channels arranged in a staggered pattern means that the centered position of a projection on the lower edge of a light circulation channel is naturally off-centered on the upper edge of the adjacent light circulation channel. In the example illustrated, where the circulation channels return to their position every two rows, it is thus possible to halve the light intensity of the overall beam projected onto the area imaging the projection and this makes it possible to reduce the potential inconvenience for the driver.

[0161] Figures 10 to 12 illustrate a second embodiment which differs from what has been previously described insofar as the lighting device no longer comprises a single light source but a plurality of light sources 41, 42, here two in number, and a plurality of output microlenses 24, in a number equivalent to the number of light sources, in the same circulation channel. This second embodiment makes it possible in particular to produce, for the same lighting surface formed by the output face of the matrix of output microlenses, a plurality of light functions.

[0162] Each of the light sources is selectively addressable. In particular, each of the first and second light sources 41, 42 is thus capable of being switched on and off independently of one another, for example by means of an electronic control device.

[0163] In the example illustrated, two output microlenses 241, 242 are present in the same channel 5 and two light functions are provided by the light device 1 of the invention with the first light source 41 which participates, when it is activated, in generating a first light function and with the second light source 42 which participates, when it is activated, in generating a second light function.

[0164] In the illustrated example, the first light function is a lighting function and more particularly here a non-blinding lighting for other road users, known as "dipped beam headlights", which involves a beam with a sharp cut-off, in accordance with what has been described previously. The second light function may be a position light function, for which the power of the light source is reduced, or a signaling function and more particularly here a signaling of the presence of the vehicle, known as "daytime running lights".

[0165] 11 results from the choice of the light functions to be provided by the light device from the characteristics concerning the light sources 41, 42 and / or concerning in particular the focusing of the output microlenses.

[0166] The light source associated with the performance of this or that type of light function is thus chosen according to the light intensity that this light function must or must not provide in order to comply with automobile regulations. Furthermore, the position of a light source relative to a defined plane comprising the main optical axis may depend on the light function to be performed and in particular on the sharpness of the contours of the light beam to be provided. In particular, in the exemplary embodiment where the first light function is a “low beam” type lighting function and where the second light function is a signaling function, the first light source 41 allowing the performance of the first light function may be closer to the defined plane than the second light source 42 allowing the performance of the second light function.

[0167] More particularly, the distance of the light sources from the defined plane can be determined as a function of the angle from the main optical axis 10 that one wishes to give to the light rays leaving the collimator when one or other of the light sources is activated. Thus, the light sources are distant from each other, in the vertical direction as illustrated in Figure 10 in particular, but also in the transverse direction depending on the number and arrangement of the light sources. By distant from each other, it is understood that the light sources are not in contact with each other.

[0168] The light device 1 is thus particular in this second embodiment in that the light emission means 4 comprises a plurality of selectively addressable light sources 41, 42, in that the collimator 3 common to these light sources reorients the light rays emitted into a beam of parallel rays which impacts each input microlens 20 with an angle of incidence specific to the activation of such or such light source, in that within each light circulation channel 5 the input microlens 20 is configured to converge the rays towards a first output microlens 241 or towards a second output microlens 242 according to the inclination of the rays entering this light circulation channel 5, each output microlens 241, 242 on which the rays converge being focused on the input microlens 20.

[0169] It is notable that for a given light circulation channel 5 there is a single input microlens 20 which has an effect on the propagation of the rays, regardless of the light function implemented. In this second embodiment, the first output microlens 241 differs in particular from the second output microlens 242 associated in the same light circulation channel 5 in that the output microlenses focus on different zones of the same input microlens 20 or in that, for a given circulation channel, one of the output microlenses does not have a focusing point or plane while one of the output microlenses is configured as mentioned previously to focus on the input face of the input microlens of this light circulation channel.In this way, at least one of the microlenses creates a sharp image of the input microlens, and for example of one of the edges of the input microlens, while another output microlens does not create a sharp image of an edge or does not create a sharp image of the shape of the input microlens, i.e. is not imaging. In particular, the focusing of the first output microlens 241 is carried out on the edge 200 of the input face of the input microlens 20 which forms a cut-off of the projected beam, while the second output microlens 242 is focused substantially at the center of the input microlens 20.

[0170] In the various ray tracings schematically produced in Figures 10 to 12 to illustrate the description, the rays emitted by the first light source 41 are represented in bold lines and rays emitted by the second light source 42 are represented in thinner lines.

[0171] The collimator 3 is configured such that, when the light rays come from the first light source 41, these light rays emerge from the collimator 3 with a main inclination of a first angle α1 relative to the main optical axis 10, taking into account, as specified, a delta of divergence of the rays due to the fact that the source is not point-like. This results in a first angle of incidence of the light rays arriving at each of the input microlenses. In this context, and as can be seen in FIGS. 11 and 12, the light rays are deflected by each input microlens 20 of a light circulation channel 5 to converge in the vicinity of a first output microlens 241 arranged at the end of this light circulation channel 5.The first output microlens 241 has an object focus Fl located on the lower edge 200 of the input microlens 20, and more particularly as illustrated in FIG. 11 on the projection 201 formed on this lower edge 200.

[0172] In this way, all the rays emitted by the first light source 41 are directed towards a first output microlens 241, since all the rays entering a circulation channel of the matrix are made to converge towards a first output microlens 241 and therefore do not escape from one light circulation channel to another. Therefore, all these rays participate in forming the overall projected beam corresponding to the first light function, so that the light efficiency of the function is optimal.

[0173] Furthermore, for each projected image, intended to be superimposed on the others to form the overall projected beam, one portion is sharper than the others, namely the portion corresponding to the lower edge of the input face of the input microlens on which the output microlens is focused. This sharper portion advantageously forms the cutoff of the beam.

[0174] The second light source 42 is made active by appropriate control of an electronic control device associated with the light device. The second light source 42 emits rays towards the collimator 3, 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.

[0175] The collimator 3 is configured such that, when the light rays come from the second light source 42, these light rays emerge from the collimator 3 with a main inclination of a second angle a2 relative to the main optical axis 10, again taking into account, as specified, a delta of divergence of the rays due to the fact that the source is not point-like. This results in a second angle of incidence of the light rays arriving at each of the input microlenses. In this context, the light rays are deflected by each input microlens 20 to be focused on a second output microlens 242 arranged at the end of the light circulation channel 5. The second output microlens 242 has an object focus F2 centered on the input microlens 20, at a distance from the edges of this input microlens.In this way, the edges of the input microlens are not sharp in the image projected by the output microlens and this makes it possible not to create any hindrance in the performance of a signaling function.

[0176] According to the invention, it is thus possible to project two distinct light beams onto the same lighting surface, by passing through the first output microlens 241 of a light circulation channel the rays focused by the input microlenses 20 when a first light function is desired and by passing through the second output microlens 242 of this same light circulation channel the rays focused by the input microlenses 20 when a second light function is desired.

[0177] The first output microlens 241 thus participates in generating, by superimposing all the images projected by the first output microlenses, a light function of cut-off lighting, as previously mentioned, and in particular a lighting function of the dipped beam type.

[0178] The second output microlens 242 participates in generating, again by superimposing all the images projected by the second output microlenses, a light function without a clear outline and for example a signaling function of the daytime running light type.

[0179] Of course, in the second embodiment, means for blurring the bottom of the beam could be provided as mentioned previously and for example consisting of an increase in the focal length of the output microlenses. In this case, the focal length remains the same for the two output microlenses of the same light circulation channel and is modified from circulation channel to circulation channel, when the light device is configured so that the first output microlens images an edge of the input microlens and the second output microlens images the center of this input microlens. As previously mentioned, it can be envisaged that one of the output microlenses, for example having the function of participating in the realization of a signaling function, is not imaging, or imaging but with a focal length which is not equal to the depth of the channel, thus generating a blurred image.In these latter cases, the increase in the focal lengths of the output microlenses mentioned at the beginning of the paragraph is considered as a function of the output microlens imaging the input face.

[0180] Figure 11 illustrates a first implementation of this second embodiment, with the output microlenses 241, 242 of the same light circulation channel 5 which are arranged vertically one above the other. This figure 11 makes it possible to illustrate more particularly a ray tracing within the matrix device, with, in accordance with what was done for figure 10, the rays emitted by the first light source 241 in bold lines and the rays emitted by the second light source 242 in finer lines.

[0181] In the illustrated example, in accordance with what has been described previously for at least certain figures, the lower edge 200 delimiting the entrance face of the entrance microlens 20 comprises a projection 201 which is intended to be imaged to form a step 101 in a projected overall beam 100 with cut-off.

[0182] As mentioned, each input microlens 20 is configured to converge the light rays passing through it onto one or other of the output microlenses 241, 242 arranged at the opposite end of the light circulation channel 5 depending on the inclination of the rays entering the input microlens. In the example illustrated, the first rays arriving at the input microlens with a first inclination when the first light source 41 is activated are directed towards a convergence point substantially at the center of a first output microlens 241 associated with the light circulation channel. In the example illustrated in FIG. 11, the first output microlens 241 is arranged under a second output microlens 242 of the same light circulation channel.

[0183] When the second light source 42 is activated, it is the second rays arriving on the input microlens with a second inclination which are directed towards the output face of the matrix device, here towards a convergence point substantially at the centre of the second output microlens 242 associated with the light circulation channel.

[0184] Figure 12 illustrates a different implementation of the second embodiment with a lateral juxtaposition of the output microlenses common to the same light circulation channel. This figure shows, in top view, two neighboring light circulation channels along this transverse direction of lateral juxtaposition.

[0185] In the example illustrated, the input microlenses 20 are configured to converge the light rays precisely on the output face of the output microlenses 241, 242, without this being limiting of the invention as mentioned previously.

[0186] In this figure, in accordance with what was done for figures 10 and 11, the rays emitted by the first light source 41 are shown in bold lines and the rays emitted by the second light source 42 in finer lines.

[0187] Again, each input microlens 20 is configured to converge the light rays passing through it onto one or other of the output microlenses 241, 242 arranged at the opposite end of the light circulation channel 5 depending on the inclination of the rays entering the input microlens.

[0188] In this embodiment, the first output microlens 241 is also focused on the edge 200 of the input face 210 of the input microlens 20 which comprises the projection 201 while the second output microlens 242 is focused on the center of this input microlens 20.

[0189] It is however notable here that the projection 201 is displaced laterally relative to the central portion of the input microlens 20, to find itself opposite the first output microlens 241. The optical axis 11 of this first output microlens 241 can be aligned with the projection 201, or have a slight lateral offset so as to compromise between the sharpness of the step in the cutoff of the beam and the desired lateral extent of the projected beam.

[0190] The invention as just described makes it possible to meet the aim it set itself, namely to design a light device comprising a matrix device which is easy to produce, and in particular without a mask interposed between the microlens matrices, which allows the production of at least one light function.

Claims

CLAIMS 1. A light device (1) comprising at least one light emitting means (4), a collimator (3) and a microlens matrix device (2), the light emitting means (4) being configured to emit light rays towards the matrix device (2) via the collimator (3), the matrix device (2) comprising at least one input microlens matrix (21) having an input face facing the outside of the matrix device opposite the collimator, an output microlens matrix (22) having an output face facing the outside of the matrix device opposite the input microlens matrix, and a main optical axis (10) intersecting the two microlens matrices (21, 22), the device being characterized in that at least one light circulation channel (5) arranged along the main optical axis (10) is continuously formed by a microlens input (20) and at least one output microlens (24,241, 242), the input microlens (20) being configured to converge the substantially parallel beams of rays coming from the collimator (3) into a convergence zone on the output face of the at least one output microlens (24, 241, 242) associated with this light circulation channel, the at least one output microlens (24, 241, 242) being configured to image the input face of the input microlens (20) associated with this light circulation channel (5)., 2. Light device (1) according to claim 1, characterized in that, within a light circulation channel (5), the at least one output microlens (24, 241) is focused on an edge (200) of the input face of the input microlens (20).

3. Lighting device according to the preceding claim, characterized in that the edge (200) of the entrance face of the entrance microlens (20) on which the at least one exit microlens (24, 241) is focused has a projection (201).

4. Lighting device (1) according to one of the preceding claims, characterized in that the at least one light circulation channel (5) is arranged along the main optical axis (10) being formed on one side by a single input microlens (20) and on the other side by a plurality of adjacent output microlenses (241, 242).

5. Light device (1) according to claim 4, characterized in that the output microlenses (241, 242) of the same light circulation channel (5) are configured to have object foci (F) positioned differently on the input face of the input microlens (20) of this light circulation channel (5).

6. A light device (1) according to the preceding claim, in combination with claim 2 or 3, wherein one of the output microlenses (241) is focused on the edge (200) of the input microlens (20) and wherein the other output microlens (242) is focused substantially on the center of the input face of the input microlens (20).

7. Luminous device (1) according to claim 4, characterized in that only one output microlens of the plurality of output microlenses (241, 242) of the same light circulation channel (5) is configured to have an object focus (F) on the entry face of the entry microlens (20) of this light circulation channel (5).

8. Lighting device (1) according to one of the preceding claims, characterized in that at least two of the microlenses (20, 24, 241, 242) have different focal lengths, from one light circulation channel (5) to the other.

9. Luminous device (1) according to the preceding claim, characterized in that at least two of the light circulation channels (5) have a longitudinal dimension which varies from one light circulation channel to the other.

10. Light device (1) according to one of claims 8 or 9, in combination with claim 3, characterized in that the dimension of a projection (201) within an input microlens (20) varies as a function of the longitudinal dimension of the light circulation channel (5) associated with this input microlens (20) and / or the focal length of the output microlens (24) configured to image the input face of said input microlens (20).

11. Illumination device (1) according to one of the preceding claims, characterized in that the optical axis (11) of at least one output microlens (24, 241, 242) is offset relative to a central longitudinal axis of the associated light circulation channel (5).

12. Lighting device (1) according to one of the preceding claims, in combination with claim 3, characterized in that the position of a projection (201) formed on an edge (200) of the input microlens (20) relative to a central longitudinal axis of the associated light circulation channel (5) is different from one input microlens to an adjacent input microlens.

13. Luminous device (1) according to one of the preceding claims, characterized in that it comprises opaque elements arranged against the input face of the matrix device (2) so as to overlap an edge common to two neighboring input microlenses (20).

14. Lighting device according to one of the preceding claims, characterized in that the light emission means (4) comprises a plurality of light sources (41, 42), in particular selectively addressable, the collimator (3) being common to the plurality of light sources (41, 42) and configured to conform the light rays emitted by each light source into a beam of substantially parallel rays directed towards the matrix device (2), with an angle of inclination of the beam of substantially parallel rays relative to the main optical axis (10) which is different depending on the activated light source, the lighting device (1) being characterized in that it comprises a first light source (41) the activation of which participates in generating a first light function and a second light source (42) the activation of which participates in generating a second light function or an additional portion of the first light function,light rays emitted by the first light source (41) being made convergent by the input microlens (20) of a light circulation channel (5) onto a first output microlens (241) of this light circulation channel, light rays emitted by the second light source (42) being made convergent by the same, input microlens (20) on a second output microlens (242) of this light circulation channel.

15. Motor vehicle comprising at least one light device (1) according to any one of the preceding claims.

Images