Lighting module of a vehicle lighting device

Abstract

The present invention relates to a lighting module (2) of a lighting device including an optical element (4), the input surface (14) of which is provided with converging optical patterns (30) and the output surface (18) of which has an at least partially opaque outer face, and having a plurality of apertures (26) forming non-opaque zones (22), each non-opaque zone (22) being located on or near a focusing zone (Z1, Z2) for focusing light rays passing through one of the converging optical patterns (30), the lighting module (2) furthermore being characterised in that at least some of the converging optical patterns (30) are configured to generate a double focus along two orthogonal convergence planes (P1, P2), and in that the apertures (26) have an elongate shape with a main axis of elongation (28) which is perpendicular to a first convergence plane (P1).

Description

Light module of a vehicle lighting system

[0001] The present invention relates to the fields of automotive and optics, and more specifically concerns lighting devices for motor vehicles.

[0002] The lighting devices consist of projectors placed at the front of a motor vehicle and which include one or more light modules whose function is to project a beam of light, intended to illuminate the road scene in front of the motor vehicle, and / or a signaling beam, intended to make the motor vehicle more easily visible to road users or intended to give these same road users an indication on the driving of the vehicle.

[0003] The lighting beams can be either a low beam (dipped headlight) with a range of approximately 70 meters, designed to illuminate the road without dazzling other road users, or a high beam with a greater range of at least 100 meters. Achieving these beams requires high light intensity, and therefore necessitates the inclusion of a specific light source and associated optics within the corresponding lighting module.

[0004] Signaling beams can consist of position lights, daytime running lights (DRLs), or flashing lights, though this list is not exhaustive. Such signaling beams are created using specific light sources and optics, distinct from those used for standard lighting, and it is common to have a dedicated lighting module for creating a signaling beam.

[0005] Today, car manufacturers, particularly due to the use of light-emitting diodes (LEDs) and other optical elements that allow for the creation of light modules in various shapes, want to offer distinctive lighting signatures specific to a manufacturer or car brand. In other words, manufacturers want their car brand to be recognizable by the shape of the illuminated area of ​​the lighting functions when the lighting devices—that is, the headlights at the front of the vehicle—generate a particular beam of light.

[0006] Furthermore, it is also desired that the configuration of the lighting device meet specific aesthetic criteria when the headlight has an off appearance, for example by adding an opaque screen to intensify the dark appearance of the output surface of the lighting device.

[0007] It is in this dual context that the invention is situated, aiming for a lighting device that allows the contradictory technical effects of having on the one hand a regulatory lit appearance or one specific to the aesthetic wishes of a manufacturer and on the other hand an opaque off appearance.

[0008] To this end, the invention proposes a luminous module for a vehicle lighting device, comprising:

[0009] - at least one light ray emission assembly configured to send said light rays towards an input surface of an optical element of said light module,

[0010] - the input surface of the optical element being provided with a plurality of converging optical patterns, configured to respectively direct, along an optical axis of the luminous module, the rays towards at least one focusing zone in the vicinity of an output surface of the optical element opposite to said input surface,

[0011] said luminous module being remarkable in that the optical element is configured to present an external face at least partially opaque, the external face at least partially opaque having a plurality of openings forming non-opaque zones distributed on said external face at a distance from each other, each non-opaque zone being located on or in the vicinity of a focal zone of rays originating from the set of light rays emitting and passing through one of the converging optical patterns,

[0012] said luminous module being moreover remarkable in that at least some of the converging optical patterns are configured to generate a double focusing along two orthogonal convergence planes, with a first focusing zone along a first convergence plane offset along the optical axis relative to a second focusing zone along a second convergence plane, and in that the openings have an elongated shape with a principal elongation axis, said principal elongation axis being oriented perpendicular to the first convergence plane.

[0013] By "principal axis of elongation oriented perpendicular to the first plane of convergence," we mean that the elongated shape of the openings is such that this elongation has a component perpendicular to the first plane of convergence. In other words, when the openings are viewed from the direction corresponding to the intersection of the first and second planes of convergence, they appear elongated along a direction perpendicular to the first plane of convergence.

[0014] The light module has an optical axis corresponding to the general direction of the light beam that passes through the non-opaque areas of the optical element.

[0015] The optical element is a transparent plate, for example made of polycarbonate (PC), coated with a layer of opaque material on its exit surface, the non-opaque areas being perforations distributed within the opaque layer. This embodiment has the advantage of being simple and inexpensive to manufacture.

[0016] The external face of the optical element should be understood as the face of that optical element that faces outwards from both the optical element and the vehicle, towards the road. It should be noted that the external face of the optical element can be formed by a face of the material that constitutes the optical element and allows the propagation of light rays within the optical element, or by a face of a coating layer that contributes to the formation of the optical element, or even by both the face of the material forming the optical element and the face of a coating layer, depending on the point considered on the external face. More specifically, the external face of the optical element can be formed by the face of a coating layer, except in the areas corresponding to the openings, where it is formed by the face of the material forming the optical element.

[0017] The optical element is said to be at least partially opaque on its outer surface due to the presence of non-opaque areas. In other words, the outer surface is opaque except in the areas of the perforations. The overall opacity coefficient of the outer surface is high, with non-opaque areas representing less than ten percent of the output surface. These non-opaque areas allow light from the entire ray emission to pass through. These non-opaque areas allow sufficient light to pass through, the term "opaque" being understood as allowing little or no light to pass through, that is, in all cases less than 5% of the light incident on the opaque area, meaning it has a transmission of less than 5%.Furthermore, a transmission of less than 1% is advantageous to ensure that only the openings appear luminous when the light rays are sent by the light ray emission assembly.

[0018] The presence of non-opaque areas on or near a focal point means that an optical pattern on the input surface converges the light rays it encounters into at least one focal point. This focal point is located on the output surface at the level of a non-opaque area, or is positioned near this output surface, opposite a non-opaque area. At least one focal point may be centered on the non-opaque area on the surface of the optical element.

[0019] More particularly, according to the invention, and as previously mentioned, the light module is configured so as to generate, for light rays focused by a given convergent optical pattern, a double focusing of these light rays according to respective convergence planes which are perpendicular to each other and with focalization zones offset along the optical axis and thus positioned more or less close to the output surface of the optical element.

[0020] In particular, double focusing can be defined such that, according to the first plane of convergence, the light rays from the light ray emission set converge in the vicinity of the output surface, and more particularly in the vicinity of the external face of the optical element, and such that, according to the other of said planes of convergence, the second plane of convergence, the light rays from the light ray emission set converge at a distance from said output surface.

[0021] By "at a distance" from the output surface, we mean, for example, that the rays converge at a distance from the output surface that is at least 15% of the optical element's thickness. By comparison, we can define "in the vicinity" of the output surface as a convergence of the rays at a distance from the output surface that is less than 5% of the optical element's thickness. We should therefore understand from this latter value that the focal zone can be moved away from the output surface, along the first plane of convergence, as long as all the converging rays pass through the slit formed by the aperture, even if the opaque nature of the outer face is achieved by a coating that forms part of the optical element and is applied to the output surface of that optical element.

[0022] In this context, the focusing of light rays by a converging optical pattern can be achieved on the output surface, and specifically on one of the apertures of the output surface. Considering the first plane of convergence, this ensures that the rays pass through the apertures in a narrow portion. This allows, on the one hand, for limiting the size of the apertures in a direction perpendicular to the optical axis and parallel to the first plane of convergence, and on the other hand, for a large initial angular opening of the beam projected onto the road. This prevents the rays from scattering within the optical element before reaching the aperture, which would result in the output face impacting an area covered by an opaque material.Furthermore, the focusing of these light rays by the same converging optical pattern can be done at a distance, for example beyond, the exit surface by considering the second plane of convergence, to give the beam a second angular aperture reduced compared to the first angular aperture, this implying increasing the size of the aperture in a direction perpendicular to the optical axis and parallel to the second plane of convergence.

[0023] Dual focusing allows for the formation of a beam with a wider angular aperture in one of the two directions considered. For example, convergence near the projection surface produces a first angular aperture, and convergence further from the projection surface produces a second angular aperture that is smaller than the first. This makes it possible to achieve regulatory or aesthetic requirements, with different angular apertures depending on the projection plane, while minimizing losses in luminous efficacy.

[0024] Thus, according to the invention, a lighting function, whether regulatory or aesthetic, is achieved by passing light rays through openings whose dimensions are optimized to provide, on the one hand, a particularly opaque, off-screen appearance when no lighting function is implemented, and on the other hand, to limit the loss of luminous efficacy that could result from blocking light rays by openings that are too small. The size of the opening is limited in the direction associated with the plane of convergence along which the focus is made on the output surface, in order to minimize the impact of the opening's size on the off-screen appearance of the output surface, and a sufficient size is ensured for the opening in the other direction so that light rays focused downstream of the output surface are not blocked by an opaque surface.

[0025] The shape of the light beam is defined when this beam is projected onto a screen positioned at least 10 meters in front of the vehicle, the device being its standard mounting position on the vehicle, specifically a screen perpendicular to the optical axis of the light module. This light beam may have a shape wider than it is tall, particularly when implementing a signaling function, or any other beam shape, for example, taller than it is wide, which may be the case, for instance, when implementing an aesthetic function, or even of equal height and width.

[0026] The lighting module may include one or more of the following features, taken alone or in combination.

[0027] According to an optional feature of the invention, each opening is associated with a unique converging pattern.

[0028] According to an optional feature of the invention, at least one aperture is associated with several converging patterns. In other words, the non-opaque area thus formed is located on or near several focal zones, each focal zone corresponding to a specific converging pattern. In particular, said non-opaque area may have a principal elongation axis oriented perpendicular to the first convergence plane. In other words, the converging patterns such that said non-opaque area is located on or near the focal zones of said optical patterns are arranged in a direction having a component perpendicular to said first convergence plane.

[0029] According to an optional feature of the invention, along the second convergence plane, the light rays from the light ray emission assembly converge beyond said output surface, outside the optical element.

[0030] According to an optional feature of the invention, along the second convergence plane, the light rays emanating from the light-ray emission assembly converge at a distance from said output surface, inside the optical element. This can be advantageous for maintaining sufficient material thickness of the optical element when the beam angle is high.

[0031] The apertures are oblong or rectangular in shape, with varying dimensions depending on their elongated direction. The elongated shape, for example oblong, allows these apertures to be precisely positioned around the point of impact of the light rays on the output face. Advantageously, the oblong shapes are oriented to allow the emission of a light beam with the correct angular apertures in the correct directions.

[0032] It follows from the above that the aperture has an elongated shape, with a principal axis of elongation that defines its orientation on the output surface. The aperture is said to have a horizontal, or vertical, orientation if its principal axis of elongation is horizontal or vertical. The orientation of the aperture is defined by the offset of the two focal points. In particular, the principal axis of elongation is perpendicular to the orientation of the first plane of convergence when the latter is associated with the focusing of light rays onto the output surface.

[0033] The invention thus enables the performance of seemingly contradictory functions: the implementation of a lighting function that must comply with precise regulatory or aesthetic constraints, and the ability to have an opaque surface that appears homogeneous, without imperfections and therefore without apparent perforations, when the vehicle's lights are switched off. Furthermore, an effective signaling function can be implemented that saves energy by limiting, within the context of a homogeneous-looking opaque surface, the amount of light rays that are unable to exit the optical element due to the opaque coating. This results in reduced electrical consumption and / or a decrease in the number of light sources required to perform the desired signaling function.

[0034] It should be understood that at least some of the converging optical patterns are configured to exhibit dual focusing insofar as, without leaving the context of the invention, some of the converging optical patterns may exhibit only single focusing, with vertical and horizontal focusing targeted on the same area, for example on the periphery of the optical element.

[0035] According to one feature of the invention, at least one opening has a large dimension along the main elongation axis which is at least three times greater than the dimension along the direction perpendicular to the main elongation axis.

[0036] By way of non-limiting example of the invention, the opening has a large dimension, along the principal elongation axis, of between 0.3 mm and 1.4 mm, and more preferably between 0.6 mm and 0.7 mm, and a small dimension, in the direction perpendicular to the principal elongation axis, of between 0.05 mm and 0.3 mm, and more preferably between 0.1 mm and 0.2 mm. More particularly, all the openings may have an elongated shape and this characteristic dimensional ratio between length and width. The numerical ranges throughout this description are to be understood inclusive.

[0037] Regarding the small size mentioned, it can be advantageous to have a dimension between 0.05 mm and 0.15 mm, so that the apertures are barely visible or even impossible to distinguish for an outside observer. It can also be advantageous to choose a larger dimension, between 0.15 mm and 0.3 mm, to facilitate the manufacturing of the optical element, and in particular to allow for satisfactory absorption of manufacturing tolerances. This latter choice can also allow the use of diodes with a larger emitting surface, and therefore less expensive, or collimators, as described below, with a shorter focal length.

[0038] Regarding the large dimension mentioned, the preferred ratio mentioned between 0.6mm and 0.7mm is a compromise between a large dimension allowing to reduce the opening of the beam in the associated direction and a small dimension advantageous to reduce the visibility of the openings.

[0039] According to an optional feature of the invention, the adjacent apertures may have, along the main elongation axis, a large dimension such that the adjacent apertures merge so as to form a long aperture covering the associated converging optical patterns.

[0040] According to an optional feature of the invention, the optical element comprises a layer of opaque material coating the exit surface of the optical element and which forms said external face of the optical element, except in the areas of the openings where applicable.

[0041] According to an optional feature of the invention, the opaque material layer can be a layer of paint. The paint layer can be sprayed onto a transparent plate to form a layer between 30 and 50 microns thick, a thickness sufficient to allow for perforations, for example, by laser ablation. Using a paint with a thickness of approximately 30 to 50 microns ensures a uniform appearance with the surrounding bodywork. For example, it is possible to use the same type of paint as the bodywork, particularly in terms of color and / or finish, such as a matte or metallic appearance.

[0042] According to an optional feature of the invention, the opaque material layer is an ink layer. The ink layer can be deposited by inkjet printing, so as to form a layer thinner than the previously mentioned paint layer, for example on the order of 10 micrometers.

[0043] According to an optional feature of the invention, the opaque material layer can be a layer of a metal oxide. In this case, the thickness can be on the order of 1 micrometer or less. Such a layer can be obtained by vacuum deposition of a metal oxide, for example chromium oxide, to give the desired opacity.

[0044] It is understood that the more the thickness of the opaque material layer is reduced, the more the width of the opening can be reduced, because the thickness of the opaque material does not penalize or only slightly penalizes the propagation of rays passing through the opening in this material and which have an angle relative to the optical axis higher than other rays.

[0045] Furthermore, the use of ink eliminates the need for laser ablation to create the perforations necessary for light transmission. The ink deposit allows for the direct application of the correct shape by drawing it around the perforations. The manufacturing process is thus simpler, as it avoids an additional laser ablation step, and more reliable, as it prevents damage to the optical element's surface from the laser light.

[0046] According to an optional feature of the invention, the opaque material layer coating the output surface of the optical element is covered by a transparent or translucent varnish layer suitable for filling the gaps.

[0047] According to an optional feature of the invention, the light module is capable of emitting a signaling beam. In particular, the signaling beam is a daytime running light (DRL) type beam. By way of example, a DRL signaling beam has a horizontal beam angle of approximately 40° and a vertical beam angle of approximately 20°.

[0048] In this context, the first convergence plane is horizontal, and it is the light rays made to converge horizontally by a converging optical pattern that are focused onto the output surface. The size of the aperture in the horizontal direction can then be limited since the majority of rays are focused onto the aperture in this direction. The second convergence plane is vertical, and it is the light rays made to converge vertically by a converging optical pattern that are focused downstream of the output surface, so the size of the aperture in the vertical direction must be larger than the size of the aperture in the horizontal direction to block a minimum number of light rays. The main axis of elongation of the aperture is then vertical, perpendicular to the first convergence plane.

[0049] Also, without these examples forming an exhaustive list, the beam emitted by the light module is a signaling beam of the flashing light type, direction indicator.

[0050] Alternatively, the light beam emitted by the light module is an aesthetic beam, the orientation of which differs from that of a daytime running light beam. When the light module serves a purely aesthetic function, meaning it is configured according to the invention to present a homogeneous, off-glow appearance when the light sources are off, notably due to the presence of an opaque coating on the optical element, and to present a specific, non-regulatory configuration of the projected light beam when the light sources are on, the height and width of the projected beam may differ from those described above, and in particular, the height may be equal to or greater than the beam width. In this context, the orientation of the perforations is modified.For example, a light beam used for aesthetic purposes may have a greater vertical dimension than its horizontal dimension when projected onto a wall 25 meters from the vehicle. In this context, it is understood that the converging optical patterns are configured so that focusing along the vertical convergence plane is achieved on the output surface of the optical element, and focusing along the horizontal convergence plane is achieved downstream of the output surface, outside the optical element. Simultaneously, the perforations formed in the output surface are oriented so that the principal elongation axis is horizontal.

[0051] According to an optional feature of the invention, the optical element has a thickness of approximately 2mm, the thickness being measured between the apex of a convergent optical pattern of the input surface and the outer face of the output surface, excluding the thickness of the opaque coating, and the opaque coating has a thickness of less than 50 microns.

[0052] It is understood that the thickness of the opaque coating affects the smallest dimension of the aperture, since this narrow dimension of the aperture, or aperture width, is defined as small as possible based on focusing the light rays onto the output surface. To prevent rays diverging beyond the output surface from being blocked by the opaque walls delimiting the aperture through which the rays propagate outwards from the light module, the aperture width can be slightly increased. For example, for an opaque coating thickness of approximately 40 microns, the aperture width can be increased by about 30%, thus increasing it by about 20 microns for an initial aperture width of approximately 0.1 millimeters.

[0053] According to an optional feature of the invention, the cumulative surface area of ​​the openings at the outlet is less than or equal to ten percent of the total surface area of ​​said outlet. It is understood that the openings must allow for a lighting function by letting through sufficient light emitted by the light source(s), but that they must be sized so as not to detract from the appearance when the lights are off, that is, not to negatively impact the vehicle's aesthetics when the lights are switched off.

[0054] According to an optional feature of the invention, the converging optical patterns are made in the form of bumps on said input surface.

[0055] According to an optional feature of the invention, the converging optical patterns exhibit curvature in at least two directions, with at least a first curvature defined to focus the light rays onto the first focal zone along the first convergence plane and at least a second curvature defined to focus the light rays onto the second focal zone along the second convergence plane. The converging optical patterns have a freeform surface, and more particularly a polynomial surface in two variables.In the case where the focusing along the first plane of convergence is more pronounced than the focusing along the second plane of convergence, with the light rays focused along the first plane of convergence being directed onto the exit surface and the light rays focused along the second plane of convergence being directed downstream of the exit surface, the first curvature is stronger than the second curvature.

[0056] According to an optional feature of the invention, the light beam emission assembly comprises at least one light beam source and an optical guiding element configured to collect light beams emitted by said source and to direct them towards the optical element.

[0057] The light emission system comprises at least one primary light source and, optionally, an optical device, such as a reflector or collimator, positioned opposite the primary light source to collect the light rays and focus them into a beam directed towards the entrance surface of the optical element. The light emission system generates a beam of substantially parallel rays directed towards the optical element. The term "substantially parallel" means that the beam may have an angular aperture due to the size of the light source.

[0058] According to an optional feature of the invention, the light emission assembly comprises several first light sources and several optical guiding elements, each of said optical guiding elements being configured to collect light rays from a corresponding light source among said sources. This increases the power of the rays arriving at the entrance surface of the optical element.

[0059] According to an optional feature of the invention, said optical guiding elements are deflectors forming portions of a parabolic mirror, offset from one another. The deflectors are, for example, offset along the optical axis of the light rays arriving at the entrance surface of the optical element. This arrangement makes it possible to reduce the size of the light module. In an alternative embodiment, the optical guiding elements are collimators that are at least partially refractive, such as dioptric collimators, or other types of deflectors.

[0060] The invention also relates to a lighting device, comprising a housing defining a cavity in which at least one lighting module, as just mentioned, is disposed.

[0061] According to an optional feature of the invention, the external face of the optical element helps to close the cavity of the housing.

[0062] According to an optional feature of the invention, the lighting device comprises a transparent closing panel, separate from the optical element, capable of closing the housing and allowing the rays emanating from said optical element to pass through it. The closing panel is, for example, a glass or a transparent plastic cover externally protecting the lighting module according to the invention and thus defining an illuminated surface representative of the vehicle's visual signature.

[0063] The lighting device is typically a light or a spotlight, usually located at the front of the vehicle.

[0064] Other features and advantages of the invention will become apparent from the following description on the one hand, and from several illustrative and non-limiting examples of embodiments given with reference to the attached schematic drawings on the other hand, in which:

[0065] schematically represents a light module according to the invention, in a preferred embodiment of the invention.

[0066] illustrates the path of light rays through an optical element of the light module according to the invention, in this preferred embodiment of the invention,

[0067] illustrates an output surface of the optical element of the,

[0068] illustrates the path of light rays through the optical element viewed from a different angle than that shown in the image, and

[0069] illustrates a detailed view of a light module according to the invention, showing a cutout formed in the thickness of the optical element and the presence of a varnish covering an opaque coating in which the cutout is formed.

[0070] The invention relates to a light module 2 of a light device for a vehicle, as illustrated in the figure, said light module being configured to generate in particular a signaling beam.

[0071] The lighting device housing the light module according to the invention can be mounted on the front side end of a vehicle and take the form of a vehicle headlight. The vehicle's lighting device may also include other light modules, possibly of different types, provided that it comprises at least one light module as described below.

[0072] The lighting device comprises a housing, here schematically represented in dotted lines, which forms a cavity in which various optical components of a lighting module 2 are housed, including at least one light ray emission assembly and an optical element 4. In the illustrated example, the cavity of the housing is closed by a transparent closing wall, without this being a limitation of the invention, this closure of the housing being able to be effected by the optical element itself.

[0073] Each light-emitting assembly includes a light source, here a light-emitting diode (LED) 5, 6 mounted on a printed circuit board 8 that supplies power to the diode. Each LED 5, 6 contributes to generating a signaling beam, for example, a direction indicator beam, a position light, or a daytime running light. For example, this LED 5, 6 can be considered a first light source with a low temperature, capable of emitting sufficient luminous flux to create a signaling beam.

[0074] In the illustrated example, the light module 2 comprises two light emission sets, each with a light-emitting diode (LED) 5, 6, and these LEDs are positioned opposite each other, being arranged on opposite faces of the printed circuit board. Alternatively, the light module comprises a single emission set, or more than two emission sets. Furthermore, although in this embodiment each emission set comprises a single LED, alternatively each emission set comprises one or more LEDs.

[0075] Each light-emitting assembly of the light module 2 also includes an optical guiding element 10, 12 configured to deflect the light rays emitted by the corresponding light-emitting diode towards the optical element, which will be described below. The presence of an optical guiding element, as well as its configuration, is not a limitation of the invention, provided that the emission assembly directs light rays towards the optical element.

[0076] In the illustrated example, the optical guiding element 10, 12 is a parabolic reflector, and the light-emitting diode 5, 6 associated with the light-emitting diode assembly is positioned at the focal point of the parabolic reflector 10, 12, respectively associated with each light-emitting diode. Thus, the rays emitted by the light-emitting diodes 5, 6 are collected by the respective parabolic reflectors 10, 12, which direct them to an entrance surface 14 of the optical element 4, mentioned previously and also part of the light-emitting module 2. Here, the parabolic reflector 10 collects the rays emitted by the diode 5 and directs them to the entrance surface 14, while the parabolic reflector 12 collects the rays emitted by the diode 6 and directs them to the entrance surface 14.

[0077] The emission assemblies, and in particular the parabolic reflectors 10 and 12, are configured so that the emitted light rays are directed towards this entrance surface 14, along an optical axis 100 substantially parallel to a longitudinal direction X corresponding to the longitudinal direction in the vehicle's frame of reference, that is, a direction parallel to the direction of travel of the vehicle. A vertical direction Z orthogonal to the longitudinal direction X corresponds to the vertical direction in the vehicle's frame of reference, that is, a direction perpendicular to the road on which the vehicle is traveling. Finally, a transverse direction Y orthogonal to the horizontal direction X and the vertical direction Z corresponds to a transverse direction in the vehicle's frame of reference.

[0078] Using two parabolic reflectors 10 and 12, each associated with one of the LEDs 5 and 6, on either side of a printed circuit board 8, with a longitudinal offset of the LEDs 5 and 6, allows for a compact lighting module to perform one or more signaling functions. As mentioned earlier, alternatively, a single LED or more than two LEDs can be used, and similarly, a single optical guiding element or more than two optical guiding elements could be implemented to generate a signaling beam directed onto the input surface 14 of the optical element 4.

[0079] In another variant, instead of parabolic reflectors 10, 12, each light ray emission set of the light module 2 includes collimators, or other optical devices, which collect the rays from the light-emitting diodes 5, 6 to send them in a beam of substantially parallel rays onto the entrance surface 14 of the optical element 4.

[0080] The optical element 4 takes the form of a plate extending parallel to the transverse direction Y, positioned across the longitudinal direction of propagation of the light rays from the emitting assembly. The optical element is arranged along the path of the light rays from the emitting assembly. In the illustrated example, the optical element is positioned between this emitting assembly and the transparent closing wall 16 of the lighting device.

[0081] The optical element 4 has, opposite the previously mentioned inlet surface 14, an outlet surface 18 which is turned towards the outside of the vehicle, and here towards the transparent closing wall 16 of the lighting device.

[0082] In the first embodiment, the optical element 4 is inclined with respect to a plane perpendicular to this longitudinal direction. In particular, this optical element 4 can be inclined to follow a curve of the vehicle in which the lighting device is located. Here, the optical element 4 is inclined at 45° around the transverse axis with respect to such a perpendicular plane, the upper edge of the optical element 4 being brought closer to the light-emitting assembly by this inclination.

[0083] The optical element 4 is made of transparent material, for example glass, polycarbonate (PC) or polymethyl methacrylate (PMMA), and has an external face of the exit surface 18 that is at least partially opaque.

[0084] As mentioned previously, opaque areas 20 of the optical element 4 are considered as such when they allow little or no light to pass through, i.e. in all cases less than 5% of the light entering the optical element in an area of ​​equivalent surface area.

[0085] In the illustrated example, the opacity of the output surface 18 is achieved by the presence of an opaque layer 24 on the outer face of the output surface. This opaque layer 24 has a thickness of approximately 30 to 50 microns, while the corresponding thickness of the optical element can be approximately 2 millimeters. These thicknesses are measured along parallel directions, with the thickness of the optical element being measured from the outer face of the input surface to the outer face of the output surface.

[0086] The opaque material layer 24 can be a film glued to the output surface 18 or, as is the case here in the illustrated example, this opaque material layer 24 is made by a paint deposit on the output surface 18, notably visible on laou la.

[0087] Openings 26 are formed in the opaque material layer, here in the thickness of the paint layer, so as to form non-opaque areas 22 and allow the passage of light rays through the opaque material layer 24 when a lighting function is required.

[0088] In the diagram, the optical element is schematically represented with opaque zones 20, shown here hatched, which represent a major portion of the output surface 18 of the optical element 4, and non-opaque zones 22, two in number here, which form the only areas through which light rays can pass. The dimensions and number of the non-opaque zones 22 are not representative of reality, but it is noticeable from this schematic representation that the perforations 26 forming the non-opaque zones 22 are arranged at a distance from each other, notably to distribute the perforations over the output surface and allow for a visually similar, if not identical, appearance to a completely opaque area, without any perforations.

[0089] Figures 2 and 3 illustrate more specifically the optical element 4, and in particular the outer face of its output surface 18, that is, the face facing outwards of the optical element. The opaque material layer 24 has openings 26 distributed over the output surface 18, which form areas in which the transparent material of the optical element is not covered by an opaque material.It is understood that the presence of opaque material on the output surface 18 can prevent the propagation of light rays from the light emission assemblies, in particular here light-emitting diodes 5, 6, and which arrive on the input surface 14 of the optical element 4 and it is understood in this context that the openings 26 made in this opaque material have the effect of locally allowing the light from these light emission assemblies to pass through the optical element 4, via these openings 26, and subsequently exit the housing, if necessary via a transparent closing wall 16. These openings 26 are for example formed by laser cutting on the layer of opaque material 24.

[0090] The perforations 26 in the opaque material layer 24 are small enough not to alter the "off" appearance of the lighting device. For example, they represent less than 10% of the opaque surface of the optical element 4. Obtaining the perforations by laser cutting the opaque material layer, as described above, makes it possible to obtain perforations of small dimensions, thus meeting this requirement for the overall size of the perforations, and in a simple manner. For example, an optical element made of two materials, with an opaque material injected throughout the thickness of the optical element and a transparent material injected at specific points within the opaque material, would be more difficult to manufacture and would not allow for perforations of such small dimensions.For example, the openings in the light module according to the invention do not have dimensions, in length or in width, that is to say along the direction of a principal elongation axis 28 of the opening or along a direction perpendicular to this principal elongation axis 28, which are greater than 1 millimeter.

[0091] The plate forming the optical element also has converging optical patterns 30 on its entrance surface 14. These patterns serve to direct as many rays as possible from the light emission sets, as they pass through the optical element 4, towards the openings 26. More specifically, a converging optical pattern 30 is configured to deflect the light rays appropriately towards the exit surface 18 of the optical element in the area of ​​one of the openings 26 specifically associated with it. These converging optical patterns 30 are here implemented as raised areas on the entrance surface 14 of the optical element 4. The corresponding surface area is calculated so that the rays from the light emission sets, which arrive at these raised areas parallel to each other along the longitudinal direction X, converge towards the openings 26.As will be detailed below, the bosses forming the converging optics 30 are configured to converge the light rays in the vicinity of the openings 26, but in different areas depending on the plane considered, and more particularly with two focal areas Z1, Z2 offset axially, along the optical axis 100 of the light module, as will be described below.

[0092] It should be noted that in one variant, the emission sets each generate a converging beam, these beams not being parallel to each other. In this case, some converging optical patterns 30 are oriented and / or configured differently from the others on the entrance face 14, to allow the converging beams from their respective emission set to pass through the openings 26 in the opaque material layer 24.

[0093] The bosses forming the converging optical patterns 30 are positioned at a distance from one another, with a flat surface between each boss. The bosses can be contiguous, which allows for good photometric efficiency by avoiding wasted rays in intermediate areas. By contiguous, it is understood that the bosses are touching, but that a transition radius may exist between them, this radius being intrinsically linked to the manufacturing of the optical element.

[0094] Finally, a possible embodiment of the optical element 4 is shown, obtained by assembling two parts pressed together to form a contact surface 32 between them. These two parts respectively comprise the entrance surface and the exit surface. Such an embodiment allows the position of the apertures relative to the emission assembly to be adjusted as needed on the production line. The contact surface 32 is flat to allow adjustment of the position of the parts relative to each other.

[0095] As previously mentioned, the light module 2 is remarkable in that the light rays are deflected by the converging optical patterns 30 in such a way that they are focused distinctly on a first focal zone Z1 according to a first convergence plane P1 and on a second focal zone Z2 according to a second convergence plane P2, perpendicular to the first convergence plane P1.

[0096] Dual focusing allows the formation of a beam with a wider angular aperture in one of the two directions considered. For example, the convergence of light rays, along a convergence plane, on a first focusing zone Z1 centered on the output surface 18 results in a first angular aperture of the projected beam when considering this convergence plane. Converging the light rays on a second focusing zone Z2 beyond the output surface 18, along a different convergence plane, results in a second angular aperture of the projected beam when considering this other convergence plane, which is smaller than the first angular aperture. This notably allows for the implementation of a regulatory or aesthetic function, with different angular apertures depending on the projection planes.

[0097] In particular, we can define double focusing so that according to the first convergence plane P1, the light rays from the light ray emission set converge on the first focusing zone Z1 and the output surface 18, and more particularly on the external face of this output surface, and so that according to the other of said convergence planes, the second convergence plane P2, the light rays from the light ray emission set converge on the second focusing zone Z2, beyond said output surface 18, outside the optical element.

[0098] The double focusing along perpendicular convergence planes P1, P2 is made possible by an appropriate shape of each of the converging optical patterns 30. In particular, a converging optical pattern 30 configured to generate this double focusing may have a complex shape with at least two curvatures among which a first curvature defined to generate the focusing of the light rays along the first convergence plane and a second curvature defined to generate the focusing of the light rays along the second convergence plane.

[0099] According to the invention, this double focusing, with focusing zones Z1, Z2 offset along the optical axis 100 according to the chosen convergence plane, is accompanied by an appropriate shape of the openings 26 to allow the realization of the desired luminous function, limit the impact on the off appearance of the luminous module and limit to the maximum the losses of luminous efficiency.

[0100] In this context, the focusing of light rays by a converging optical pattern 30 can be performed on the output surface 18, and specifically on one of the perforations 26 of the output surface, considering the first convergence plane P1. This ensures that the rays pass through the perforations in a narrow portion, which allows, on the one hand, for limiting the size of the perforations in a direction perpendicular to the optical axis and parallel to the first convergence plane P1, and on the other hand, for a large initial angular aperture of the beam projected onto the road. This prevents the rays from scattering within the optical element before reaching the perforation, which would result in rays impacting the output face in an area covered by an opaque material and thus being lost, reducing the optical efficiency of the lighting device.Furthermore, the focusing of these light rays by the same converging optical pattern 30 can be done beyond the exit surface 18 by considering the second convergence plane P2, to give the beam a second angular aperture reduced compared to the first angular aperture, this implying increasing the dimension of the aperture 26 in a direction perpendicular to the optical axis and parallel to the second convergence plane P2.

[0101] It follows that, as illustrated in Figure 1, the perforations 26 have elongated slot shapes on the exit surface 18. The perforations could be elliptical, with one dimension larger than the other, corresponding to the shape of the elongated slot. Generally, the perforations 26 have an elongated shape with a principal elongation axis 28 that defines the orientation of a principal dimension of the perforation 26, that is, a dimension larger than the dimension measured along a perpendicular direction. By way of a non-limiting example of the invention, the converging patterns 30 form bosses extending over a square surface with sides of one millimeter, and the perforations 26 have a width D1 of 0.12 millimeters and a length D2 of 0.6 millimeters, measured in the plane of the exit surface of the optical element 4.In this context, the main dimension of the opening 26, or length D2, is about five times greater than the dimension of the opening 26, or width D1, measured in a direction perpendicular to the direction of the main elongation axis.

[0102] To take into account the thickness of the opaque material layer 24 in which the openings 26 are formed and to prevent rays propagating out of the optical element 4 within the opening 26 from impacting an opaque wall participating in delimiting the opening, and in the context of the dimensions mentioned above, the width of the openings 26 can be increased to be about 0.2 millimeters, so that the main dimension of the opening is at least three times greater than the dimension of the opening measured in a direction perpendicular to the direction of the main elongation axis.

[0103] The double focusing of the light rays as previously described is linked to the elongated dimension of the openings 26 and their orientation, insofar as the width D1 of the opening 26, i.e. the small distance of the latter, is oriented in a direction corresponding to that of the large angular opening of the projected beam, and therefore in a direction parallel to the first plane of convergence P1 in which the light rays are focused on the exit surface 18. If the light rays are focused on the exit surface when the first plane of convergence P1 considered is horizontal, then the large angular opening of the projected beam is horizontal with a projected beam which is wider than it is tall, and in this context the opening has a width D1 which is horizontal and a length D2 which is vertical, the main elongation axis 28 of the opening 26 being oriented vertically, perpendicular to the first elongation plane.

[0104] In the illustrated example, the lighting function implemented is a DRL-type signaling beam, with a beam that is wider than it is tall when projected onto a wall in front of the vehicle. Specifically, such a beam can have an angular opening of approximately 40° horizontally and 20° vertically. In this context, the focusing of the light rays along the first convergence plane P1, horizontal, is done on the output surface 182, within the openings 26, as seen from the front, and the focusing of the light rays along the second convergence plane P2, vertical, is done downstream of the optical element 4, beyond the openings 26, as seen from the rear. The width of a 26 opening then extends horizontally, since the convergence along this plane takes place at the level of the 26 opening and the horizontal dimension of the 26 opening can be reduced to the maximum while minimizing the risk of light rays being blocked by opaque material.And the length of an opening 26 then extends vertically, or at least in a direction representative of the projection of a vertical axis onto the output surface of the optical element, that is to say an axis inscribed in the output surface 18 and orthogonal to a horizontal plane.

[0105] Figure 1 shows the view of the output surface when viewing optical element 4 from an angle of view along an axis substantially perpendicular to the plane of elongation of the optical element. In this figure, each converging optical motif 30 is represented in transparency by dashed lines on the output surface 18 of optical element 4. It can be seen that, from this angle of view, each converging optical motif 30 is located above the aperture 26 towards which it deflects the light. This is due to the fact that the rays from the light-emitting diodes 5 and 6 do not arrive parallel to the optical axis specific to each converging optical motif, since this axis is inclined, here at an angle of approximately 45 degrees, with respect to the longitudinal direction X.

[0106] Alternatively, particularly when the curvature of the vehicle on which the lighting device is mounted does not require the inclination of the optical element as previously described, the optical element can be positioned substantially perpendicular to the optical axis. A converging optical motif 30 and a perforation 26 could then be substantially aligned along the direction of the optical axis and superimposed when the optical element is viewed from an angle of vision along an axis substantially perpendicular to the plane of elongation of the optical element.

[0107] In different variations of what has just been mentioned, the converging optical patterns have a surface area different from one square millimeter, but on the order of one square millimeter, and the openings have different dimensions but always less than one millimeter.

[0108] It should be noted that the number of openings 26 and converging optical patterns 30 illustrated in figures 2 to 4 may not be representative of the exact number that would be implemented on optical element 4, in order to simplify the reading of the figures in particular.

[0109] Figure 34 illustrates an embodiment of an optical element according to the invention, in which the opaque material layer 24 is formed by a layer of paint, which is coated with a varnish 34. The varnish serves, in particular, to protect the paint layer forming the opaque material layer 24 and to prevent a large difference in refractive index as light rays pass between the optical element 4 and the outside. The varnish 34 is thus chosen to have a refractive index intermediate between that of air and that of the material chosen, for example, polycarbonate, to form the transparent plate that contributes to the optical element. The varnish 34 is, of course, transparent or translucent, to allow the light rays directed through an aperture to propagate out of the optical element to perform the desired lighting function.

[0110] The optical element 4 is obtained by the successive operations of depositing a layer of paint on a plate of transparent material, laser cutting the layer of paint up to the exit surface to make the openings 26 forming the non-opaque areas 22 on this exit surface, and finally depositing varnish 34 on the layer of paint forming the layer of opaque material 24.

[0111] The varnish 34 is chosen to be liquid so that it can fill the slot made by laser cutting in the paint layer to form the opening 26. The aim is to avoid a film forming on the surface with air trapped at the bottom of the slot.

[0112] In the illustrated example, the external surface of the varnish layer 34 is substantially flat, but one could foresee the presence of a meniscus at the opening 26, which may have the effect of widening the beam angle formed by the light rays that have passed through the opening, this effect being particularly useful in the realization of aesthetic or signaling lighting functions.

[0113] The presence of the varnish, and even more so in the presence of a meniscus at the right of the opening, offers the possibility, according to the first plane of convergence P1, of being less convergent, the convergent optical pattern being able to be configured so that the rays which it deflects according to the first plane of convergence P1 are slightly offset axially with respect to the exit surface, while remaining in the material associated with the optical element, here the material of the varnish.

[0114] It follows from the preceding description that the invention thus achieves its objective, namely to enable a vehicle to be equipped with a lighting device comprising at least one lighting module which has a homogeneous off appearance, while ensuring the performance of lighting functions and in particular regulatory signaling functions and in a context of energy saving.

Claims

Light module (2) of a vehicle lighting device, comprising: - at least one light beam emission assembly configured to direct said light beams towards an input surface (14) of an optical element (4) of said light module (2), - the input surface (14) of said optical element (4) being provided with a plurality of converging optical patterns (30), configured to respectively direct, along an optical axis (100) of the light module, the beams towards at least one focusing zone (Z1, Z2) in the vicinity of an output surface (18) of the optical element (4) opposite said input surface (14), - said light module (2) being characterized in that the optical element (4) is configured to have an at least partially opaque external face, the at least partially opaque external face having a plurality of openings (26) forming non-opaque zones (22) distributed on said external face at a distance from each other,each non-opaque zone (22) being located on or in the vicinity of a focusing zone (Z1, Z2) of rays originating from the light ray emission set and passing through one of the converging optical patterns (30), - said luminous module (2) being further characterized in that at least some of the converging optical patterns (30) are configured to generate a double focusing along two orthogonal convergence planes (P1, P2), with a first focusing zone (Z1) along a first convergence plane (P1) offset along the optical axis (100) with respect to a second focusing zone (Z2) along a second convergence plane (P2), and in that the openings (26) have an elongated shape with a principal elongation axis (28), said principal elongation axis (28) being oriented perpendicular to the first convergence plane (P1). Light module (2) according to claim 1, wherein according to the first convergence plane (P1), the light rays from the light ray emission assembly converge in the vicinity of said output surface (18), and according to the second convergence plane (P2), the light rays from the light ray emission assembly converge at a distance from said output surface (18). Light module (2) according to claim 1 or 2, in which at least one opening (26) has a large dimension along the main elongation axis (28) which is at least three times greater than the dimension along the direction perpendicular to the main elongation axis (28). Light module (2) according to any one of claims 1 to 3, wherein the optical element comprises a layer of opaque material (24) coating the output surface (18) of the optical element (4) and which forms said external face of the optical element. luminous module (2) according to the preceding claim, in which the layer of opaque material (24) coating the output surface (18) of the optical element (4) is covered by a layer of transparent or translucent varnish (34) suitable for filling the gaps (26). Light module (2) according to any one of claims 1 to 5 and capable of emitting a signaling beam. Light module (2) according to any one of claims 1 to 6, wherein the cumulative surface area of ​​the openings (26) at the level of the output surface is less than or equal to ten percent of the overall surface area of ​​said output surface (18). Light module (2) according to any one of claims 1 to 7, wherein said converging optical patterns (30) are made in the form of bosses on said input surface (14). Light module (2) according to any one of claims 1 to 8, wherein the converging optical patterns (30) have a curvature along at least two directions, at least a first curvature being defined to generate the focusing of the light rays on the first focusing zone (Z1) along the first convergence plane (P1) and at least a second curvature being defined to generate the focusing of the light rays on the second focusing zone (Z2) along the second convergence plane (P2). A luminous device comprising a housing defining a cavity in which at least one luminous module (2) according to one of claims 1 to 9 is disposed.

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