Lighting device, in particular for a motor vehicle

Abstract

The invention relates to a lighting device (100) comprising, in a stack: - a luminous structure (1) arranged to emit light, - a light-emitting array (10) comprising a set of emitting features (11) by which the light of the luminous structure (1) is emitted, - a light-transmitting array (3) comprising a set of transmitting features (33) through which the light emitted by the emitting array (10) passes, - wherein the emitting array (10) and the transmitting array (3) have spatial distributions chosen to disrupt spatial interference due to the stacking of the transmitting and emitting arrays.

Description

[0001] DESCRIPTION

[0002] Title: Lighting device, particularly for motor vehicles

[0003] [1] The field of the present invention is that of lighting devices, in particular for motor vehicles.

[0004] [2] Heating panels are known which comprise a plurality of electrodes configured to deliver heat by Joule effect by supplying an electric current to a conductive coating. See, for example, document U S2016 / 0059669.

[0005] [3] Furthermore, it is known to use lighting devices in the passenger compartment of motor vehicles. These interior lighting devices are increasingly in demand by car manufacturers.

[0006] [4] In certain types of lighting devices, when two periodic structures with similar spatial frequencies are superimposed, a Moiré effect is observed. Such a Moiré effect is observed when attempting to backlight an automotive decoration surface by combining at least two of the following: a microstructured light guide and a perforated decoration surface or textile, a light guide with a perforated radiant heating panel, a perforated radiant heating panel with a perforated decorative surface or textile.

[0007] [5] The Moiré effect is triggered by the superposition of two periodic structures. With three periodic structures, the Moiré effect is also present.

[0008] [6] The spatial interference between the patterns of these overlapping structures results in a Moiré effect that we wish to avoid.

[0009] [7] The invention aims in particular to avoid this Moiré effect on superimposed structures.

[0010] [8] The invention thus relates to a lighting device comprising, in a stacking arrangement: a light structure arranged to emit light, a light emission network comprising a set of emission patterns through which the light from the light structure is emitted, a light transmission network comprising a set of transmission patterns through which the light emitted by the emission network passes, wherein the emission network and the transmission network have spatial distributions chosen to break spatial interferences due to the stacking of the emission and transmission networks.

[0011] [9] By spatial distribution, we mean here the spatial distribution of emission patterns within the emission network, and the spatial distribution of transmission patterns within the transmission network.

[0012]

[0010] By spatial interference, we mean here the superposition of the emission patterns of the transmission network and the superposition of the transmission patterns caused by the stacking of said networks.

[0013]

[0011] According to one aspect of the invention, at least one of the transmission network or the emission network comprises emission patterns or transmission patterns following a periodic distribution, and the other of the transmission network or the emission network comprises emission patterns or transmission patterns following an aperiodic distribution chosen to break spatial interferences due to the stacking (or superposition) of the emission and transmission networks.

[0014]

[0012] By periodic distribution, we mean here that the motifs of the lattice are arranged with regular spacing between them. By aperiodic distribution, we mean here that the motifs of the lattice are arranged with spacings that vary depending on the pairs of motifs considered. In other words, two adjacent motifs are arranged with varying spacings. By aperiodic, we mean here at least a partial absence of periodicity in the lattice.

[0015]

[0013] When at least one of the networks comprises a set of patterns distributed in two dimensions, the network includes a fictitious reference point associated with each pattern, and each pattern is spaced from its associated reference point by a random distance and / or angle along a statistical distribution curve (for example, a Gaussian curve). When at least one of the networks comprises a set of patterns distributed in one dimension, the network includes a fictitious reference point associated with each pattern, and each pattern is spaced from the reference point by a random distance along a statistical distribution curve. In other words, each pattern is arranged with a spatial offset from its associated reference point. The statistical distribution curve may be a Gaussian curve or have a random component, regardless of its statistical distribution (or probability distribution).

[0016]

[0014] According to one aspect of the invention, the luminous structure forms the light-emitting array. For example, the luminous structure comprises a light guide with light-extraction microstructures that form the light-emitting array. In this case, the light-emitting array is notably distinct from primary light sources.

[0017]

[0015] In the present invention, the light emission network is understood in particular as defining a first light emission surface, and does not necessarily include one or more light sources.

[0018]

[0016] The invention thus makes it possible to provide a lighting device in which the pattern networks avoid the Moiré effect, by adding a random component in the network of at least one of the structures.

[0019]

[0017] In one aspect according to the invention, the lighting device includes a heating structure arranged to produce heat.

[0020]

[0018] In one aspect according to the invention, the lighting device includes a decoration.

[0021]

[0019] In one aspect according to the invention, the lighting device includes an emission mask arranged to form, with the light structure, the light emission network, said emission mask being in particular attached to the light structure.

[0022]

[0020] According to one aspect of the invention, the mask is made of a material which at least partially blocks the light from the light structure and includes openings to allow this light to pass through according to the emission patterns conferred by these openings.

[0023]

[0021] In one aspect according to the invention, the mask is formed by the heating structure. In other words, emission patterns are arranged on the heating structure through which the light from the luminous structure attached to the heating structure is emitted. That is to say, the heating structure comprises light emission patterns arranged for the emission of light emitted by the luminous structure, and areas arranged for absorbing the light emitted by the luminous structure. The emission mask function is performed by the heating structure.

[0024]

[0022] In one aspect according to the invention, the emission mask is disposed between the light structure and the heating structure. In other words, the emission mask function is performed by a structure having no other functions.

[0025]

[0023] In one aspect according to the invention, the lighting device includes a transmission mask arranged to form the light transmission network.

[0026]

[0024] In one aspect according to the invention, a transmission mask is formed by the decoration. In other words, the transmission patterns are arranged on the decoration through which the light emitted by the light-emitting grid is transmitted. That is to say, the decoration comprises light-transmitting patterns arranged to allow the transmission of light emitted by the light-emitting grid, and areas arranged to absorb the light emitted by the light-emitting grid.

[0027]

[0025] In one aspect according to the invention, the transmission mask is formed by the heating structure. In other words, the transmission patterns are arranged on the heating structure through which the light emitted by the emission grating is transmitted. That is to say, the heating structure comprises light transmission patterns arranged to allow the transmission of light emitted by the light emission grating, and areas arranged to absorb the light emitted by the light emission grating.

[0028]

[0026] In one aspect according to the invention, the transmission mask is disposed between the light structure and the decor, more particularly between the heating structure and the decor.

[0029]

[0027] In one aspect according to the invention, the lighting device comprises at least two light emission networks, in particular a light emission network formed by the heating structure, and a light emission network formed by the light structure, and / or a network formed by the stacking of the light structure and an emission mask disposed between the heating structure and the light structure.

[0030]

[0028] In one aspect according to the invention, the lighting device comprises at least two light transmission networks, in particular a light transmission network formed by the heating structure and a network formed by the decor, and / or a network formed by the stacking of a transmission mask and the heating structure or the decor, said transmission mask being disposed between the light structure and the decor.

[0031]

[0029] In one aspect according to the invention, the transmission patterns have a shape chosen from among a polygon, a circle, a disk, an oval, an ellipse, a line.

[0032]

[0030] In one aspect according to the invention, the emission patterns have a shape chosen from among a polygon, a circle, a disk, an oval, an ellipse, a line.

[0033]

[0031] In one aspect according to the invention, the transmission patterns and the emission patterns have the same form.

[0034]

[0032] In one aspect according to the invention, the transmission patterns and the emission patterns have a different form.

[0035]

[0033] In one aspect according to the invention, the at least one emission network comprises periodically distributed emission patterns, and the at least one transmission network comprises aperiodically distributed transmission patterns.

[0036]

[0034] According to one aspect of the invention, the lighting device comprises a functional face towards which the light produced by the light structure can be sent, this functional face being configured to diffuse the light thus received towards the outside of the lighting device, for example towards an area of ​​a vehicle interior.

[0037]

[0035] According to one aspect of the invention, the functional face is thus a face of the lighting device on which the lighting function manifests itself, for example to illuminate an area of ​​this passenger compartment or to create a luminous effect visible from the passenger compartment.

[0038]

[0036] According to one aspect of the invention, the heating and lighting structures form stacked layers.

[0039]

[0037] According to one aspect of the invention, the lighting device has a panel shape.

[0040]

[0038] According to one aspect of the invention, the lighting device is flexible, namely it can be shaped to take a predetermined form.

[0041]

[0039] According to one aspect of the invention, the lighting device includes a decoration visible from inside the passenger compartment, this decoration being for example a covering of the passenger compartment, such as for example a fabric, a leather or an aesthetic coating.

[0042]

[0040] According to one aspect of the invention, the heating structure, the lighting structure and the decoration form stacked layers.

[0043]

[0041] The lighting device according to the invention thus makes it possible to perform, in addition to the heating and lighting functions, a decoration function, for example with a predetermined leather or fabric area, visible from the passenger compartment.

[0044]

[0042] According to one aspect of the invention, the light structure includes a light engine.

[0045]

[0043] According to one aspect of the invention, the light engine is an electronic device, in particular a printed circuit board, comprising one or more LEDs (light-emitting diodes) and at least one light guide to guide the light emitted by the LED(s).

[0046]

[0044] According to one aspect of the invention, the light guide of the light engine comprises a plate in which light can propagate, this plate comprising at least one light-emitting face.

[0047]

[0045] According to one aspect of the invention, the plate has, at least locally, a flat shape, and the light-emitting face is, at least locally, flat.

[0048]

[0046] According to one aspect of the invention, the plate has a complex shape different from a flat shape.

[0047] According to one aspect of the invention, the light guide plate extends along a curved surface.

[0049]

[0048] In another aspect according to the invention, the luminous structure comprises a flexible guide sheet including a film in a material having a refractive index, this material being for example a polymer, the film forming a core of the flexible guide sheet, core in which light can propagate, this film being interposed between two layers of materials having refractive indices lower than the refractive index of the film material, this luminous structure further comprising at least one optical decoupling element configured to reflect or diffract locally light propagating in the film towards the outside of the film.

[0050]

[0049] The term "flexible guide sheet" refers to the fact that the flexible guide sheet can deform to take on a predetermined shape. For example, when the flexible guide sheet is placed on a curved (e.g., convex) surface, its deformation allows it to conform to this curved surface. The flexible guide sheet has a thin profile such that its flexibility is preserved.

[0051]

[0050] According to one aspect of the invention, the flexible guide mat has a light-emitting face emitting the light extracted by the optical decoupling element(s).

[0052]

[0051] In one aspect according to the invention, the optical decoupling elements are formed of microstructures.

[0053]

[0052] According to one aspect of the invention, the optical decoupling element(s) are transparent in the absence of guided light in the flexible guide sheet.

[0054]

[0053] According to one aspect of the invention, the optical decoupling element(s) are configured to reflect light directionally, in particular at an angle substantially perpendicular to the emission face of the flexible guide sheet.

[0055]

[0054] According to one aspect of the invention, a plurality of optical decoupling elements are made on the film forming the core of the flexible guide sheet.

[0056]

[0055] According to one aspect of the invention, the optical decoupling elements are integrated into the film.

[0057]

[0056] In one aspect according to the invention, the film is made of polycarbonate (PC), or polymethyl methacrylate (PMMA), or thermoplastic polyurethane (TUP), or polyethylene terephthalate (PET).

[0058]

[0057] The invention further relates to a vehicle comprising a passenger compartment, said passenger compartment comprising said at least one lighting device as described above.

[0058] In one aspect according to the invention, the vehicle comprises a front-end module, said front-end module comprising the lighting device as described above.

[0059]

[0059] Other features, details and advantages of the invention will become clearer upon reading the following description on the one hand, and several illustrative and non-limiting examples of embodiments given with reference to the accompanying schematic drawings on the other hand, in which:

[0060]

[0060] [Fig 1] Figure 1 is a cross-sectional representation of a lighting device according to an example of an embodiment of the invention;

[0061]

[0061] [Fig. 2] Figure 2 is a cross-sectional representation of a lighting device according to another embodiment of the invention;

[0062]

[0062] [Fig. 3] Figure 3 is a cross-sectional representation of a lighting device according to yet another embodiment of the invention;

[0063]

[0063] [Fig. 4] Figure 4 is a representation of the emission network of the lighting device of Figure 1;

[0064]

[0064] [Fig. 5] Figure 5 is a representation of the emission network 10 according to another embodiment of the invention;

[0065]

[0065] [Fig. 6] Figure 6 is a representation of the transmission network of the lighting device of Figure 1;

[0066]

[0066] [Fig. 7] Figure 7 is a schematic representation of a heating structure of the lighting device of Figure 2;

[0067]

[0067] [Fig. 8] Figure 8 is a schematic representation of a luminous structure of the lighting device of Figure 1.

[0068]

[0068] The features, variants, and different embodiments of the invention can be combined in various ways, provided they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features, described hereafter in isolation from the other described features, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0069]

[0069] Figure 1 shows a lighting device 100 according to an embodiment of the invention, comprising, in a stack: a light structure 1 arranged to emit light, a light emission network 10 comprising a set of emission patterns 11 through which the light from the light structure 1 is emitted, as illustrated in Figure 4, a light transmission network 3 comprising a set of transmission patterns 33 through which the light emitted by the light emission network 10 passes, as illustrated in Figure 6.

[0070]

[0070] The transmission network 10 and the transmission network 3 have spatial distributions chosen to break spatial interferences due to the stacking of the transmission network 10 and the transmission network 3.

[0071]

[0071] By spatial distribution, we mean here the spatial distribution of the emission patterns 11 within the emission network 10, and the spatial distribution of the transmission patterns 33 within the transmission network 3.

[0072]

[0072] By spatial interference, we mean here the superposition of the emission patterns 11 of the emission network 10 and the superposition of the transmission patterns 33 caused by the stacking of said emission network 10 and transmission network 3.

[0073]

[0073] In the invention, at least one of the transmission network 3 or the emission network 10 comprises emission patterns or transmission patterns following a periodic distribution, and the other of the transmission network 3 or the emission network 10 comprises emission patterns or transmission patterns following an aperiodic distribution chosen to break spatial interferences due to the stacking (or superposition) of the emission and transmission networks.

[0074]

[0074] In the example described, it is the set of emission patterns 11 of the light emission array 10 that exhibits the aperiodic distribution chosen to break spatial interference due to stacking. The transmission patterns 33 of the transmission array 3, on the other hand, exhibit a periodic distribution.

[0075]

[0075] By periodic distribution, we mean here that the motifs of the lattice are arranged with regular spacing between them. By aperiodic distribution, we mean here that the motifs of the lattice are arranged with spacings that vary depending on the pairs of motifs considered. In other words, two adjacent motifs are arranged with varying spacings. By aperiodic, we mean here at least a partial absence of periodicity in the lattice.

[0076]

[0076] In the example in Figure 4, the emission patterns 11 of the light emission grating 10 are distributed in two dimensions, and the light emission grating 10 includes a fictitious reference point Af associated with each pattern 11, and each pattern 11 is spaced from the reference point Af associated with it by a random distance and / or angle following a statistical distribution curve, for example a Gaussian curve.

[0077]

[0077] When the lattice 10 comprises a set of patterns 11 distributed along one dimension (as illustrated in Figure 5), the lattice 10 includes a fictitious reference point Af associated with each pattern 11, and each pattern 11 is spaced from the reference point Af by a random distance following a statistical distribution curve. In other words, each pattern is arranged with a spatial offset from its associated reference point Af. The statistical distribution curve may be a Gaussian curve or have a random component, regardless of its statistical distribution (or probability distribution).

[0078]

[0078] In the example of Figure 1, the light structure 1 forms the light-emitting grating 10. Here, the light structure 1 is a light guide with light-extraction microstructures 12 that form the light-emitting grating 10. In this case, the light-emitting grating 10 is notably distinct from primary light sources. Each light-extraction microstructure 12 corresponds to a motif 11.

[0079]

[0079] The invention thus makes it possible to provide a lighting device 100 in which the pattern networks avoid the Moiré effect, by adding a random component in the network 10.

[0080]

[0080] In the example of Figure 1, the lighting device 100 includes a decoration 30, in the form of a layer of decoration.

[0081]

[0081] A transparent support 2 is interposed, in the stack, between the luminous structure 1 and the decoration layer 30.

[0082]

[0082] The lighting device 100 includes a transmission mask 31 arranged to form the light transmission network 3.

[0083]

[0083] In the example described in Figure 1, the transmission mask 31 is formed by the decoration 30. In other words, the transmission patterns 33 are arranged on the decoration 30 through which the light emitted by the emission grating 10 is emitted. In other words, the decoration 30 comprises the light transmission patterns 33 (for example defined by perforations in the decoration layer 30) arranged to allow the transmission of the light emitted by the light emission grating 10, and areas (here solid areas between the perforations) arranged to absorb the light emitted by the light emission grating 10.

[0084]

[0084] In another example illustrated in figure 2, the lighting device 100 includes an emission mask 14 arranged to form, with the light structure 1, the light emission network 10, said emission mask 14 being attached to the light structure 1.

[0085]

[0085] The mask 14 is made of a material which at least partially blocks the light from the light structure 1 and includes openings (or perforations) to allow this light to pass through according to the emission patterns 11 conferred by these openings (or perforations).

[0086]

[0086] The lighting device 100 includes a heating structure 4 arranged to produce heat. The heating structure 4 will be described in more detail below.

[0087]

[0087] In the example illustrated in figure 2, the mask 14 is formed by the heating structure 4. The emission patterns 11 are arranged on the heating structure 4 through which the light from the light structure 1 attached to the heating structure 4 is emitted.

[0088] In other words, the heating structure 4 includes light emission patterns 11 (defined by perforations in the heating structure 4) arranged for the emission of light emitted by the light structure 1, and areas arranged to absorb the light emitted by the light structure 1. The emission mask function 14 is played by the heating structure 4.

[0089]

[0088] In the example illustrated in figure 2, the transmission mask 31 is formed by the decoration 30 (as in the example in figure 1).

[0090]

[0089] In an unillustrated variant, the emission mask is arranged between the light structure 1 and the heating structure 4. In other words, the emission mask function is played by a structure having no other functions.

[0091]

[0090] In another example illustrated in Figure 3, the transmission mask 31 is formed by the heating structure 4. In other words, the transmission patterns 33 are arranged on the heating structure 4 through which the light emitted by the emission grating 10 is transmitted. In other words, the heating structure 4 comprises the light transmission patterns 33 arranged to allow the transmission of the light emitted by the light emission grating 10, and areas arranged to absorb the light emitted by the light emission grating 10.

[0092]

[0091] In the example illustrated in Figure 3, the light structure 1 forms the light emission network 10. As in the example in Figure 1, the light structure 1 is a light guide with light extraction microstructures 12 that form the light emission network 10.

[0093]

[0092] In an unillustrated variant, the transmission mask is arranged between the heating structure 4 and the decor 30.

[0094] The transmission patterns 33 have a shape chosen from among a polygon, a circle, a disk, an oval, an ellipse, and a line. In the example in Figure 6, these are transmission patterns 33 in the shape of circles.

[0094]

[0095] The emission patterns 11 feature a shape chosen from a polygon, a circle, a disk, an oval, an ellipse, or a line. In the example in Figure 4, the emission patterns 11 feature a circular shape.

[0095]

[0096] The transmission patterns 33 and the emission patterns 11 have the same shape, or different shapes.

[0096]

[0097] In the examples described, the lighting device 100 has a functional face 200 towards which the light emitted by the light structure 1 can be sent, this functional face 200 being configured to diffuse the light thus received towards the outside of the lighting device 100, for example towards an area of ​​a vehicle interior.

[0097]

[0098] The functional face 200 is thus a face of the lighting device 100 on which the lighting function manifests itself, for example to illuminate an area of ​​this passenger compartment or to create a luminous effect visible from the passenger compartment.

[0098]

[0099] In the examples in Figures 2 and 3 in which the lighting device 100 includes a heating structure 4, the entire heating structure 4 is placed between the functional face 200 and the light structure 1 so that light from this light structure 1 passes through the heating structure 4 before reaching the functional face 200.

[0099]

[0100] As illustrated in Figure 7, the heating structure 4 includes a resistive layer 51 arranged to produce heat when an electric current passes through it. This resistive layer 51 defines a masking zone made of a material configured to absorb the light emitted by the light structure 1 and prevent its passage, for example, a carbon-containing material.

[0100]

[0101] The heating structure 4 comprises, on a substrate 58 (for example in non-woven material), two electrodes 52, which are in electrical contact with the resistive layer 51 so as to allow an electric current to flow through the resistive layer 51 between these two electrodes 52. The resistive layer is for example deposited on the substrate by printing, screen printing, lamination of several materials or by physical vapor deposition (well known as PVD for "Physical Vapor Deposition" in English).

[0102] These electrodes 52 have parallel sections 53 between which is the resistive layer 51, and transverse sections 54 which are connected to electrical supply wires 55.

[0101]

[0103] The heating structure 50 includes light-filled areas 59 formed, for example, by perforations in the heating structure 50, and a deposit of an electrically conductive material in these perforations, configured to allow light to pass through. The light-filled areas 59 are configured to allow the passage of electric current within said light-filled areas 59.

[0102]

[0104] The clear areas 59 are transparent or translucent and configured to allow light from the light structure 1 to pass through and form light emission patterns 11 or light transmission patterns 33, as appropriate.

[0103]

[0105] The lighting device 100 has a panel shape, and is flexible, namely it can be conformed to take a predetermined shape.

[0104]

[0106] Decor 30 is visible from inside the passenger compartment, this decor 30 being for example a trim of the passenger compartment, such as for example a fabric, a leather or an aesthetic covering.

[0105]

[0107] The lighting device 100 according to the invention thus makes it possible to perform, in addition to the heating and lighting functions, a decorative function, for example with a predetermined leather or fabric area, visible from the passenger compartment.

[0106]

[0108] Figure 8 shows an example of a luminous structure 1 comprising a flexible guide sheet 110, said sheet having a film 111 at its core. This film 111 is capable of receiving light rays through a light injection edge 114 and of reflecting the light rays in the direction along the Ox axis substantially perpendicular to the surface of the flexible guide sheet 111 through a light-emitting face.

[0107]

[0109] A flexible guide sheet is defined as an optical guiding element in which one dimension is significantly smaller than the other two dimensions in space, for example, smaller by one or more orders of magnitude. Here, we consider a flexible guide sheet whose thickness along the Ox axis is at least two orders of magnitude smaller than its dimensions along the Oxy plane in which the flexible guide sheet 110 extends.

[0108]

[0110] The film 111 comprises a set of optical decoupling elements 113 formed by microstructures on one face of the film 111 extending along the Oy axis. The microstructures 113 are capable of reflecting light rays guided in the flexible film 111 away from the flexible guide sheet 110, in particular in a direction along the Ox axis perpendicular to the surface of the sheet 110.

[0109]

[0111] Microstructures 113 define emission patterns

[0110]

[0112] The film is made of polycarbonate (PC), or polymethyl methacrylate (PMMA), or thermoplastic polyurethane (TUP), or polyethylene terephthalate (PET).

[0111]

[0113] The flexible film 111 can have a thickness, i.e., the dimension along the Ox axis, of between 10 and 1000 micrometers. More precisely, the thickness of the flexible film 111 can be between 50 and 1000 micrometers, for example, between 100 and 500 micrometers, preferably 150 micrometers. Alternatively, the flexible guide sheet 110 has a thickness between 10 and 1000 micrometers. More precisely, the thickness of the flexible film 111 can be between 50 and 1000 micrometers, for example, between 100 and 500 micrometers, preferably 150 micrometers.

[0112]

[0114] The aforementioned materials, combined with a low thickness as described above, allow the production of a flexible and transparent film 111. Other materials may be used for the composition of the flexible film 111. However, according to the invention, it is preferable to use deformable and transparent materials.

[0113]

[0115] The flexible guide sheet 110 further includes one or two protective layers 112.1 and 112.2, which provide mechanical protection for the flexible film 111.

[0114]

[0116] Since the guide sheet 110 is flexible, it is not necessarily contained in a plane but can be curved or shaped, depending on the position in which it is placed and the mechanical stresses applied to it.

[0115]

[0117] The propagation of light rays in the flexible film 111 is done by total internal reflection thanks to the difference between the refractive index of the flexible film 111 and that of at least one adjacent layer, here an adhesive layer applied on at least one face of the flexible film.

[0116]

[0118] In the illustrated example, the flexible film 111 is bonded to the protective layers 112.1 and 112.2 by adhesive bonding. Specifically, an adhesive layer 115.1,

[0117] 115.2, here a layer of glue, is located between the flexible film 111 and each protective layer 112.1, 112.2, and this on both sides of the flexible film 111 to make the protective layers 112.1, 112.2 adhere to the flexible film 111.

[0118]

[0119] The chosen adhesive is transparent and has a different refractive index than the flexible film, thus enabling total internal reflection within the flexible film 111. In other words, due to the difference in refractive index, light rays propagating within the flexible film undergo total internal reflection upon encountering the interface between the flexible film and the adhesive layer at an angle of incidence less than normal. Therefore, the guiding sheet 110 is capable of guiding light by total internal reflection, for example, from an input zone, here slice 114, to an output zone.

[0119]

[0120] A coating of optical decoupling elements 113 formed by microstructures can be applied to one of the faces of the flexible film 111, in particular the light-emitting face, or integrated into the flexible film 111. The coating of microstructures 113 may, in particular, have a thickness along the Ox axis of less than 20 micrometers. These optical decoupling elements are configured 113 to reflect light directionally, in particular at an angle substantially perpendicular to the emission face of the flexible guide sheet 110.

[0120]

[0121] Microstructures are defined as structures, or irregularities in the flexible film, whose dimensions are less than a few micrometers. Microstructures thus also include nanometric structures.

[0121]

[0122] A light source 120 (for example an LED or light-emitting diode in French) linked to a light injection element allows light to be injected into the flexible guide sheet 110.

[0122]

[0123] In another embodiment of the invention, the light sources can be part of a light engine.

[0123]

[0124] According to one aspect of the invention, the light engine is an electronic device, in particular a printed circuit board, comprising one or more LEDs (light-emitting diodes) and at least one light guide to guide the light emitted by the LED(s).

[0124]

[0125] According to one aspect of the invention, the light guide of the light engine comprises a plate in which light can propagate, this plate comprising at least one light-emitting face.

Claims

DEMANDS

1. Lighting device (100) comprising, in a stack: a light structure (1) arranged to emit light, a light emission array (10) comprising a set of emission patterns (11) through which the light from the light structure (1) is emitted, a light transmission array (3) comprising a set of transmission patterns (33) through which the light emitted by the emission array (10) passes, wherein the emission array (10) and the transmission array (3) have spatial distributions chosen to break spatial interferences due to the stacking of the emission and transmission arrays.

2. Lighting device (100) according to the preceding claim, wherein at least one of the transmission network (3) or the emission network (10) comprises emission patterns (11) or transmission patterns following a periodic distribution, and the other of the transmission network (3) or the emission network (10) comprises emission patterns or transmission patterns following an aperiodic distribution chosen to break spatial interferences due to the stacking (or superposition) of the emission and transmission networks.

3. Lighting device (100) according to any one of the preceding claims, wherein the light structure (1) forms the light emission array (10), and in particular the light structure (1) comprises a light guide with light extraction microstructures which form the light emission array (10).

4. Lighting device (100) according to any one of the preceding claims, wherein the lighting device (100) comprises an emission mask arranged to form, with the light structure (1), the light emission network (10), said emission mask being in particular attached to the light structure (1).

5. Lighting device (100) according to the preceding claim, wherein the emission mask is formed by the heating structure (4).

6. Lighting device (100) according to any one of the preceding claims, wherein the lighting device (100) comprises a decoration (30) and a transmission mask is formed by the decoration.

7. Lighting device (100) according to any one of the claims previous, in which the transmission patterns (33) have a shape chosen from a polygon, a circle, a disk, an oval, an ellipse, a line, and the emission patterns (11) have a shape chosen from a polygon, a circle, a disk, an oval, an ellipse, a line.

8. Lighting device (100) according to any one of the preceding claims, wherein the lighting device (100) has a panel shape

9. Lighting device (100) according to any one of the preceding claims, wherein the lighting device (100) is flexible, namely it can be shaped to take a predetermined form

10. Vehicle comprising a passenger compartment, said passenger compartment comprising said at least one lighting device (100) according to any one of the preceding claims.

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