Lighting device for a motor vehicle

Abstract

The invention relates to a lighting device (10) for a motor vehicle (1), the lighting device being configured to perform at least one lighting function and comprising: - a support (11); - a plurality of light sources (14) attached to the support (11); - a grid (12) comprising a plurality of cells (13), each cell (13) being positioned facing a light source (14) attached to the support (11); - an output lens (15) covering the grid (12), the grid (12) extending between the support (11) and the output lens (15); the lighting device (10) being characterised in that it comprises an optical film comprising a microstructure configured to modify the distribution of the light coming from at least one light source (14) and / or in that at least one light source (14) is off-centre with respect to a central axis (C) of the cell (13) with which the light source (14) is associated.

Description

Luminous device for motor vehicle

[0001] The present invention relates to a lighting device for a motor vehicle configured to perform at least one lighting function. The technical context of the present invention relates to the field of signaling devices for motor vehicles. Generally speaking, these signaling devices comprise one or more lighting devices and make it possible to signal the presence of a motor vehicle. They are also used to transmit certain messages to other motor vehicles. Signaling devices equipped with lighting devices also make it possible to provide signaling functions or even to offer a stylish lighting function.

[0002] In the prior art, lighting devices for a motor vehicle are known, comprising light sources configured to emit light rays, each light source being optically coupled to a light guide so that at least a portion of the light rays generated by each light source is injected into the associated light guide and forms, at an output face, a matrix network of cells. Each cell is thus controlled so as to be able to individually generate one or more light zones with defined contours, such as "light pixels" making it possible to create numerous lighting functionalities on motor vehicles. Such lighting functionalities make it possible in particular to indicate to a neighboring motor vehicle one or more pieces of information relating, for example, to a state of the motor vehicle equipped with such a signaling device and / or equipped with such a lighting device.For example, such light devices can indicate information relating to the state of charge of an electric traction battery, a breakdown, a speed and / or a future trajectory of the motor vehicle.

[0003] A disadvantage of these lighting devices concerns their arrangement on the motor vehicle. Generally, these lighting devices are arranged at a front face of a motor vehicle and / or at a rear face, and sometimes on at least one lateral side of the motor vehicle. However, the front and / or rear faces of a motor vehicle are generally curved, so that the normal of one of these faces is not always parallel to the direction in which the motor vehicle is to move. In other words, the angle of inclination between the normal of the faces on which the lighting devices are intended to be arranged and the axis of the direction of travel of the motor vehicle leads to light rays from said lighting devices not always being oriented in the same direction as that of the presumed trajectory of the motor vehicle, which can cause weakened lighting.

[0004] The aim of the invention is to provide a device improving the lighting devices known from the prior art. In particular, the invention proposes a simple, compact, economical and reliable device, which makes it possible to provide a solution or at least elements of a solution to the technical problem formulated above.

[0005] To this end, the invention relates to a lighting device for a motor vehicle, said lighting device being configured to perform at least one lighting function, the lighting device comprising:- a support;- a plurality of light sources fixed to the support;- a grid comprising a plurality of cells, each cell being positioned opposite a light source fixed to the support;- an outlet glass covering the grid, said grid extending between the support and the outlet glass;

[0006] the light device comprising an optical film comprising a microstructure configured to modify the distribution of light from at least one light source and / or at least one light source being eccentric relative to a central axis of the cell with which said light source is associated.

[0007] According to one embodiment, the grid comprises a bottom wall and partitions configured to delimit the plurality of cells, and the bottom wall comprises openings intended to be positioned opposite the light sources fixed to the support.

[0008] According to one embodiment, the grid is obtained by molding, each cell of the grid has a cell height, and at least part of the partitions have a draft angle so as to define a draft margin which satisfies the equation x = h / tan(α), in which x designates the draft margin, h designates the cell height and α designates the draft angle.

[0009] According to one embodiment, each cell of the grid has a cell width and an offset distance for a light source eccentric with respect to the central axis of the cell with which it is associated satisfies the following inequality: d ≤ w / 2 + x, in which d denotes the offset distance, w denotes the cell width and x denotes the clearance margin.

[0010] According to one embodiment, the grid comprises a plurality of notches configured to allow flexing of the grid.

[0011] According to one embodiment, the plurality of notches is arranged in the bottom wall of the grid.

[0012] According to one embodiment, the microstructure of the film is isotropic.

[0013] According to one embodiment, the microstructure of the film is anisotropic.

[0014] The invention also relates to a motor vehicle equipped with at least one lighting device as defined previously.

[0015] According to one embodiment, the grid is obtained by molding, each cell of the grid has a cell height, and at least a portion of the partitions have a draft angle so as to define a draft margin which satisfies the equation x = h / tan(α), in which x denotes the draft margin, h denotes the cell height and α denotes the draft angle, and there is an angle of inclination between an axis normal to the surface of the support of the lighting device and a longitudinal axis of the motor vehicle, and the offset distance of a light source of the lighting device relative to the central axis of the cell of the grid of the lighting device satisfies the following equation:

[0016] d ≥ h.tan(θ) – w / a with d > 0, where d denotes the offset distance, h denotes the cell height, θ denotes the angle of inclination between the axis normal to the surface of the light device support and the longitudinal axis of the motor vehicle, w denotes the cell width and x denotes the clearance margin.

[0017] The attached drawings represent, by way of example, an embodiment of a lighting device for a motor vehicle according to the invention. 1 represents a motor vehicle equipped with a lighting device according to the invention. 1 represents a perspective view of a lighting device according to the invention.

[0018] It represents a perspective view of a grid of the light device of the.

[0019] It represents a detail view of the grid of the.

[0020] The figure represents a schematic sectional view of the lighting device of the.

[0021] In this document, the X axis designates the longitudinal axis of the motor vehicle 1. When moving forward and in a straight line, the vehicle 1 moves from the rear to the front, in a direction parallel to its longitudinal axis. The X axis is oriented from the front to the rear of the vehicle 1, that is to say in the direction of reverse travel. The Y axis designates the transverse axis of the vehicle 1. The Y axis is oriented from left to right, with left and right being defined according to the point of view of a driver of the vehicle 1. The Z axis designates the axis perpendicular to the X axis and the Y axis. It is considered that the vehicle 1 is resting on horizontal ground. The Z axis is a vertical axis, oriented from bottom to top. The X, Y and Z axes form an orthogonal reference frame. This same reference, defined by reference to a vehicle 1, will also be used to describe the lighting device 1, even when considered outside the vehicle 1, since it is intended for mounting in a specific orientation in the vehicle 1.

[0022] With reference to the, a motor vehicle 1 is described comprising a signaling device 2 which comprises a lighting device 10 according to the invention. The signaling device 2 may be arranged at the rear of the vehicle as illustrated in the, or on the contrary be arranged at the front of the vehicle 10. The lighting device 10 is configured to perform at least one lighting function and / or one signaling function. The signaling device 2 may be a rear direction indicator or a brake light, or a night-time rear position light or a rear fog light. Alternatively, the signaling device 2 could be a position light, a daytime running light, or a flashing front direction indicator.

[0023] Illustrates a light device 10 according to a first embodiment of the invention. The light device 10 is configured to display one or more pictograms in a pixelated manner in order to communicate information to an observer located at a distance from the light device 10.

[0024] The lighting device 10 comprises a support 11, a plurality of light sources 14 (not visible on the) fixed to the support 11, a grid 12 comprising a plurality of cells 13, each cell 13 being positioned opposite a light source 14 fixed to the support 11 and an outlet glass 15 (also called a closing glass) covering the grid 12, said grid 12 extending between the support 11 and the outlet glass 15 so as to be interposed between the support 11 and the outlet glass 15.

[0025] The light sources 14 are configured to emit light rays in all directions. The light sources 14 may, for example, be in the form of light-emitting diodes. By “light-emitting diodes” is meant any type of light-emitting diode, such as LEDs (“Light Emitting Diodes” in English) or OLEDs (an English acronym meaning “organic LED”), AMOLEDs (an English acronym meaning “Active Matrix Organic LED”), or FOLEDs (an English acronym meaning “Flexible OLED” which translates into French as “Flexible Organic Electroluminescent Diode”).

[0026] Advantageously, the light sources 14 are selectively controlled by a control unit which regulates an electrical supply current for each of said light sources 14 in order to regulate their emission of light rays. It is thus possible to selectively control the light sources 14 in order to obtain the desired light configuration. Multiple light configurations between an “off” configuration, in which all of the light sources 14 are off, and an “on” configuration, in which all of the light sources 14 are on, can be envisaged.

[0027] In the embodiments described here, the light sources 14 are fixed to the support 11, for example by welding. The support 11 forms a mechanical support which may be common to all the light sources 14 of the lighting device 10. By way of non-limiting example, the support 11 may take the form of a plastic plate which notably forms a printed circuit in the manner of an electronic card, or the support 11 may take the form of a flexible printed circuit film, i.e. foldable. In the preferred example where the support 11 is a flexible printed circuit film, the support 11 may be folded so as to form one or more curvatures which may have different radii of curvature.

[0028] The lighting device 10 may further comprise an electrical connection interface for supplying the light sources 14 with electrical energy via electrical connectors. The support 11 is thus configured so as to allow the routing of electrical signals to supply the light sources 14 with electrical energy and to selectively control them.

[0029] The light device 10 also comprises a grid 12 comprising a plurality of cells 13, preferably arranged adjacently. More particularly, the grid 12 may comprise a bottom wall 16 and partitions 17 configured to delimit the plurality of directly adjacent cells 13. The partitions 17 of the grid 12 delimit, for example, laterally and longitudinally a cell 13.

[0030] According to an embodiment illustrated in the, the bottom wall 16 of the grid 12 may comprise openings 18 intended to be positioned opposite the light sources 14 fixed to the support 11. In other words, when the grid 12 is mounted on the support 11 of the lighting device 1, the bottom wall 16 of the grid matches the shape of said support 11 so that each opening 18 of the bottom wall 16 is arranged opposite a light source 14. The openings 18 are for example circular in shape, as illustrated in the. In this way, each cell 13 of the grid 12 is associated with one of the light sources 14 fixed to the support 11 of the lighting device 1.

[0031] The grid 12, illustrated in more detail on the and on the, is preferably made of a flexible material so as to allow deformation of the grid 12 when it is mounted on a curved support 11 of the lighting device 1. The grid 12 is preferably formed of a material comprising silicone or elastomer. Preferably, the grid 12 can be obtained by a molding process.

[0032] According to a preferred embodiment in which the grid 12 is obtained by a molding process, the partitions 17 have a draft angle α so as to define a draft margin x. Thus, the partitions 17 can be inclined relative to the bottom wall 16 of the grid 12, which means that the partitions 17 do not necessarily extend perpendicularly to said bottom wall 16. The draft angle corresponds to the inclination of the walls of the mold necessary to facilitate the demolding of the grid 12 and in particular the demolding at the partitions 17. An example of a draft angle α is illustrated in the. Similarly, an example of a draft margin x is illustrated in the.

[0033] According to a preferred but optional embodiment, the grid 12 may comprise a plurality of notches 19 configured to allow flexion of the grid 12. The plurality of notches 19 is arranged in the bottom wall 16 of the grid 12, as illustrated in the example.

[0034] According to one embodiment, the partitions 17 which delimit the cells 13 may be opaque for the light rays emitted by the light sources 14. The opaque partitions 17 of the grid 12 may be light in color and in particular white in color. Such opaque white partitions 17 make it possible to increase the luminance of the cells 13 and therefore increase the luminance of the lighting device 1. Furthermore, the white color of the partitions 17 makes it possible to obtain a more homogeneous light signal. However, the light coming from a lighting device 10 comprising a grid 12 with opaque white partitions 17 may have a “milky” appearance and the contrast from one cell 13 to a neighboring cell 13 is not optimal.

[0035] Alternatively, the opaque partitions 17 of the grid 12 may be dark in color, particularly black. With opaque partitions 17 of black color, the contrast from one cell 13 to a neighboring cell 13 is better than with opaque partitions 17 of white color. Better contrast may contribute to better clarity of the light signal emitted by the signaling device using the light device 1. However, the light from a light device 10 comprising a grid 12 with opaque partitions 17 of black color may appear less homogeneous. Furthermore, the luminance of a light device 10 comprising a grid 12 with opaque partitions 17 of black color is lower than that of a light device 10 comprising a grid 12 with opaque partitions 17 of white color.

[0036] The partitions 17 of the grid 12 can have any shape and any size. In the various illustrated embodiments, the cells 13 delimited by the partitions 17 of the grid 12 have a polygonal shape, such as triangles, quadrilaterals, pentagons or hexagons. A grid 12 with cells 13 of polygonal shape has the advantage of being particularly stable and strong. Alternatively, the partitions 17 can be arranged so as to form cells 13 of elliptical shape, in particular in the shape of ovals and / or circles.

[0037] The cells 13 of the grid 12 may be arranged in a matrix manner, i.e. so as to form rows and columns, or the cells 13 may be arranged in a staggered manner. It is also possible for the cells 13 of the same grid 12 to have different shapes from one another and / or different sizes from one another. Having cells 13 of different shapes and / or different sizes in the same grid 12 may allow for a higher fill rate for the grid 12, i.e. a higher number of cells 13 for the grid 12.

[0038] According to a particular embodiment of the light device 10 envisaged according to the invention, at least one light source 14 may be eccentric relative to a central axis C of the cell 13 with which said light source 14 is associated. The central axis C of a cell designates an axis which passes through the middle of the cell 13 considered and which extends perpendicular to the surface of the support 11 on which the grid 12 is mounted. Thus, the central axis C of a cell is also perpendicular to the bottom wall 16 of the grid 12. An example of a central axis C is notably illustrated by a close dotted line on the.

[0039] In this particular embodiment, the eccentricity of a light source 14 of the light device 10 results in an offset distance d between said light source 14 and the central axis C of the cell 13 at the level of the support 11 on which the light source 14 considered is fixed. This offset distance d therefore corresponds to the distance between the central axis C of the cell 13 and the actual position of the light source 14 fixed on the support 11. According to a preferred embodiment, several light sources 14 are eccentric relative to the central axis C specific to each cell 13 with which the light sources 14 considered are associated.

[0040] The offset distance d for a light source 14 eccentric with respect to the central axis C of the cell 13 with which it is associated depends greatly on the geometry of said cell 13. Each cell 13 of the grid 12 may in particular have a cell width w and / or a cell height h. The width of a cell w corresponds to the distance between the partitions 17 of a cell 13 at the level of the exit glass 15. In other words, the cell width w is measured at the level of the exit glass 15.

[0041] The cell height h corresponds to the size of the partitions 17 along an axis normal N to the surface of the support 11 of the lighting device 1. In the case where the grid 12 touches the support 11 of the lighting device 10 on one side and the exit glass 15 on the other side, the cell height h can correspond to the distance between the support 11 and the exit glass 15.

[0042] The width w of a cell 13, the height h of a cell and the clearance margin x of at least one partition 17 which delimits a cell 13 are notably represented on the. In the example illustrated on the, the clearance margin x verifies the following equation: x = h / tan(α).

[0043] The offset distance d for a light source 14 eccentric with respect to the central axis C of the cell 13 with which it is associated may in particular depend on the width w of said cell 13 and the clearance margin x of at least one partition 17 which delimits said cell 13. More specifically, in a cell 13 with a partition 17 which has a clearance with a clearance margin x, the offset distance d for the light source 14 with respect to said partition 17 verifies the following inequality: d ≤ w / 2 + x. In the case where the equality is verified, this means that the light source 14 is located as close as possible to the partition 17 having the clearance angle defined previously.

[0044] Such an eccentricity of at least one light source 14 relative to the central axis C of the cell 13 with which said light source 14 is associated makes it possible more particularly to correct the orientation of the light rays coming from the light source 14 considered so as to bring this orientation closer to the direction of the presumed trajectory of the motor vehicle 1 on which the light device 10 is mounted. Such an eccentricity can in particular modify the inclination of the light rays coming from the light source 14 considered by around ten degrees.

[0045] In the case where the light device 10 comprises a curved support 11 and the entire light device 10 is curved so as to match the shape of a curved front face or rear face of a motor vehicle, an angle of inclination θ can be defined between the normal axis N to the surface of the support 11 of the light device 10 and the longitudinal axis X of the motor vehicle. In this case, the offset distance d of a light source 14 of the light device 10 satisfies the following inequality: d ≥ h.tan(θ) – w / a with d > 0.

[0046] Alternatively, the offset distance d of a light source 14 of the light device 10 can verify the following equation: d = ½(h.tan(θ) – w / a + w / 2 +x) ± w / 4 with d > 0, in which w / 4 corresponds to a margin which is proportional to the width w of the cell 13 considered.

[0047] In the case where the bottom wall 16 of the grid 12 comprises openings 18 intended to be positioned opposite the light sources 14 fixed to the support 11, and in particular openings 18 of circular shape, the central axis C of a cell 13 passes for example through the middle of the opening 18 while the light source 14 associated with said cell is not located in the middle of the opening 18; but at an offset distance d as defined previously.

[0048] Furthermore, the light device 10 may comprise an optical film comprising a microstructure configured to modify the distribution of the light coming from at least one light source 14 of the device. The optical film may for example be overmolded over the output glass 15 of the light device 1, or it may be laminated onto the output glass 15 of the light device 1. Alternatively, the optical film may for example be in contact with an upper part of the grid 12. The optical film may for example be arranged between the upper part of the grid 12 and the output glass 15 of the light device 1.

[0049] The microstructure of the optical film gives particular optical properties to the light ray at the exit of the exit window 15. More particularly, the microstructure of the optical film of the light device 1 can make it possible to correct the orientation of the light rays coming from the light source 14 and passing through the optical film so as to bring this orientation closer to the direction of the presumed trajectory of the motor vehicle 1 on which the light device 10 is mounted. Such an eccentricity can in particular modify the inclination of the light rays which pass through this optical film by an angle of between 10° and 45°.

[0050] According to some non-limiting examples, it may in particular be an optical film with an isotropic microstructure, or a film with an anisotropic microstructure called "symmetrical", or even a film with an anisotropic microstructure called "asymmetrical".

[0051] In the case where the lighting device 10 is equipped with an anisotropic film with a so-called “symmetrical” microstructure, this film can for example make it possible to alter the shape of the light beam coming from the exit face of the exit glass 15; the light beam is for example flattened along one axis and lengthened along another axis. More particularly, the optical film with a so-called “symmetrical” anisotropic microstructure which equips the lighting device 10 can be configured to lengthen the light beam coming from the exit face along a horizontal axis; and / or configured to nuance this same light beam along a vertical axis. Such a film is called a “symmetrical” anisotropic film because the light beam deformed by such a film retains a certain symmetry in its deformation.

[0052] In the case where the lighting device 10 is equipped with a film with a so-called “asymmetric” anisotropic microstructure, this film can, for example, make it possible to alter the shape of the light beam coming from the exit face 1 of the exit window 15 so that said light beam no longer has any symmetry after its deformation. This optical film also makes it possible to maximize the light intensity in the X axis of the vehicle while retaining light in the other axes, which allows the lighting device 10 to have a large lighting angle.

[0053] It is entirely possible to envisage a light device 1 which does not comprise an optical film, but in which at least one light source 14 is eccentric relative to the central axis C of the cell 13 with which said light source 14 is associated, so as to modify the inclination of the light rays coming from the light source 14 considered by about ten degrees to bring the orientation of the light beam coming from the light device 10 closer to the direction of the presumed trajectory of the motor vehicle 1 on which said light device 10 is mounted.

[0054] It is also possible to envisage a light device 1 which comprises an optical film comprising a microstructure configured to modify the distribution of the light coming from at least one light source 14 of the device and in which the light sources 14 are not eccentric relative to the cells 13. In this embodiment, only the optical properties of the microstructure of the optical film make it possible to modify the inclination of the light rays coming from the light sources 14 and passing through the optical film to bring the orientation of the light beam coming from the light device 10 closer to the direction of the presumed trajectory of the motor vehicle 1 on which said light device 10 is mounted.

[0055] Finally, it is also possible to envisage a lighting device 1 which combines these two characteristics, that is to say a lighting device 1 in which one or more light sources 14 are eccentric relative to the central axes C of the cells 13 with which the light sources 14 considered are associated, and which comprises an optical film comprising a microstructure configured to modify the distribution of the light coming from at least one light source 14. The effects of the eccentricity of the light source(s) 14 on the one hand and the effects of the microstructure of the optical film on the other hand can then be added and / or complemented to bring the orientation of the light beam coming from the lighting device 10 closer to the direction of the presumed trajectory of the motor vehicle 1 on which said lighting device 10 is mounted.

Claims

A lighting device (10) for a motor vehicle (1), said lighting device (10) being configured to perform at least one lighting function, the lighting device comprising: - a support (11); - a plurality of light sources (14) fixed to the support (11); - a grid (12) comprising a plurality of cells (13), each cell (13) being positioned opposite a light source (14) fixed to the support (11); - an output glass (15) covering the grid (12), said grid (12) extending between the support (11) and the output glass (15); the lighting device (10) being characterized in that it comprises an optical film comprising a microstructure configured to modify the distribution of the light coming from at least one light source (14) and / or in that at least one light source (14) is eccentric relative to a central axis (C) of the cell (13) with which said light source (14) is associated. Lighting device according to claim 1, characterized in that the grid (12) comprises a bottom wall (16) and partitions (17) configured to delimit the plurality of cells (13), and in that the bottom wall (16) comprises openings (18) intended to be positioned opposite the light sources (14) fixed to the support (11). Luminous device according to claim 2, characterized in that the grid (12) is obtained by molding, in that each cell (13) of the grid (12) has a cell height (h) and in that at least part of the partitions (17) have a clearance angle (α) so as to define a clearance margin (x) which satisfies the equation x = h / tan(α), in which x denotes the clearance margin, h denotes the cell height and α denotes the clearance angle. Lighting device according to claim 3, characterized in that each cell (13) of the grid (12) has a cell width (w) and in that an offset distance (d) for a light source (14) eccentric with respect to the central axis (C) of the cell (13) with which it is associated satisfies the following inequality: d ≤ w / 2 + x, in which d denotes the offset distance, w denotes the cell width and x denotes the clearance margin. A light device according to any preceding claim, characterized in that the grid (12) comprises a plurality of notches (19) configured to allow bending of the grid (12). Luminous device according to the preceding claim and according to claim 2, characterized in that the plurality of notches (19) is arranged in the bottom wall (16) of the grid (12). Luminous device according to any one of the preceding claims, characterized in that the microstructure of the film is isotropic. Luminous device according to any one of claims 1 to 6, characterized in that the microstructure of the film is anisotropic. Motor vehicle (1) characterized in that it is equipped with at least one lighting device (10) according to any one of the preceding claims. Motor vehicle characterized in that it is equipped with at least one light device (10) according to claim 3 and characterized in that there is an angle of inclination (θ) between an axis normal (N) to the surface of the support (11) of the light device (10) and a longitudinal axis (X) of the motor vehicle, and in that the offset distance (d) of a light source (14) of the light device (10) relative to the central axis (C) of the cell (13) of the grid (12) of the light device (10) satisfies the following equation: d ≥ h.tan(θ) – w / a with d > 0, in which d denotes the offset distance, h denotes the cell height, θ denotes the angle of inclination between the axis normal (N) to the surface of the support (11) of the light device (10) and the longitudinal axis (X) of the motor vehicle, w denotes the cell width and x denotes the clearance margin.

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