Patent Application
20190264884
The present invention in particular relates to a luminous motor-vehicle device, and to a lighting and/or signalling unit equipped with such a device.
One preferred application relates to the motor-vehicle industry, and regards equipment for vehicles and in particular the production of devices capable of emitting light beams, which are also referred to as lighting and/or signalling functions and which are required in general to meet regulations. The invention may allow a light beam to be produced in front of the vehicle.
Motor-vehicle signalling and/or lighting lights are luminous devices that comprise one or more light sources and an outer lens that closes the light. Simplistically, the light source emits light rays to form a light beam that is directed toward the outer lens in order to produce an illuminating land that transmits the light to the exterior of the vehicle. These functions must meet regulations with respect to light intensity and angles of visibility in particular. Known lighting and signalling modules have up to now been provided for example to emit:
In low-beam mode, as illustrated in
It is known that the second lighting zone 5 contains a cutoff 6 so that the area of the second lighting zone 5 is smaller than the area of the first lighting zone 4. The cutoff 6 makes it possible not to dazzle a driver of a vehicle driving in the lane 3.
A device for emitting a light beam is known from document EP-A1-2306074, said device comprising a plurality of light-emitting diodes that are organized in the form of a matrix array of rows and columns of diodes, each diode being associated with a complex optical element allowing a unitary portion of the overall beam to be projected. Individual and selective control of the diodes allows a resultant beam to be shaped with a great deal of shape-defining freedom. For example, to produce a low beam, only the rows of the matrix array emitting under the horizon are activated contrary to high beams; furthermore, to form a cutoff corresponding to the shape illustrated in
The present invention aims to at least partially remedy the drawbacks of the prior art.
The present invention relates, according to one aspect, to a luminous device for a motor vehicle, said device comprising a plurality of light sources and an optical system that is configured to produce an exit beam from light rays issuing from at least some of the plurality of light sources, characterized in that it includes:
Thus, the sloped shape confers on the resultant projection an inclined cutoff, this corresponding to a more gradual shape than that produced by current pixel matrix arrays, with which the cutoffs are vertical. At the same time, the rest of the upper portion of the resultant beam extends laterally from the slope uniformly by virtue of the rectangular or possibly square shape of at least one second beam starting from the first beam. Furthermore, the device still benefits from the discretization allowed by matrix arrays of LEDs, allowing the projection to be adapted to the desired lighting and/or signalling functions.
It is advantageously also possible to produce a light beam in low-beam mode that follows the geometry of the road, without needing to resort to a pivoting mechanical system and while nonetheless benefiting from a cutoff with an inclined edge.
According to another aspect, the present invention also relates to a motor-vehicle lighting and/or signalling unit equipped with at least one luminous device. This unit may comprise at least one additional device configured to produce a low-beam base beam. For example, the additional device may allow essentially below the horizon line to be uniformly illuminated. The device of the invention may for example allow at the very least the cutoff zone of a low beam to be defined.
Another aspect of the invention is a method for controlling a luminous device.
The present invention also relates to a vehicle equipped with at least one device and/or one unit according to the present invention.
According to one particularly advantageous embodiment, the device is such that the upper section of the unitary first-beam shape is a trapezium defined by the first lateral edge, a second lateral edge opposite to the first lateral edge and comprising a slope, a first base located level with the top and a second base, of width larger than the first base and opposite to the first base.
Thus a shape comprising two slopes is provided making it possible to create a beam cutoff on the right or on the left.
Advantageously, the unitary first-beam shape comprises a rectangular lower section in the continuity of the second base.
It is thus in particular possible to spread the unitary first beam downward, for example to just below the horizon line, preferably so as to create a graded joint with another beam, for example a base portion of a low beam projected in a spread way mainly or entirely under the horizon line.
According to one embodiment, the trapezium is isosceles.
Optionally, the width of the first base is equal to that of the upper section of the second unitary beam.
In this way, the second unitary beam may be located strictly in the continuity of the first base, between the two slopes; the zone of overlap of the two unitary beams is then very small and does not affect the slopes.
Preferably, the height of the upper section of the first beam is equal to the height of the upper section of the second unitary beam.
The concordance in the shape of the two unitary beams is correspondingly increased.
Furthermore, the largest width of the upper section of the first unitary beam is two times larger than the largest width of the shape of the second unitary beam.
The pitch of the pixels corresponding to the row of second unitary beams is thus half as much, providing a higher resolution in this portion for defining the resultant high beam. The number of light sources assigned to the second unitary beams is therefore higher than the number of light sources assigned to the first unitary beams, and preferably about two times higher.
Furthermore, it preferably includes, for each first illuminating unit, a first light source belonging to the plurality of light sources, and a first optical element associated with said first light source and configured to receive light from said associated first light source and to transmit one of the first unitary beams.
Optionally, each second illuminating unit includes a second light source belonging to the plurality of light sources, and a second optical element, which is associated with said second light source and configured to receive light from said associated second light source and to transmit one of the second unitary beams.
Advantageously, the first luminous module is configured to produce, for each first unitary beam, an additional first unitary beam.
Preferably, the additional first unitary beams are each located in the continuity of and above a first unitary beam.
According to one nonlimiting embodiment, the first luminous module includes at least one additional row of additional first light sources belonging to the plurality of light sources, and at least one additional row of additional first optical elements that are each associated with a different one of the additional first light sources, each additional first light source and the associated additional first optical element being configured to produce an additional first unitary beam.
Advantageously, the association of the additional row of additional first light sources and of the additional row of additional first optical elements is configured to produce an exit-beam projection that is mainly or even completely above the horizon line, in order to produce or participate in the production of a portion of a high beam.
Preferably, the second luminous module includes at least one additional row of additional second light sources belonging to the plurality of light sources, and at least one additional row of additional second optical elements that are each associated with a different one of the additional second light sources, each additional second light source and the associated additional second optical element being configured to produce an additional second unitary beam.
Advantageously, the association of the additional row of additional second light sources and of the additional row of additional second optical elements is configured to produce an exit-beam projection that is mainly or even completely above the horizon line, in order to produce or participate in the production of a portion of a high beam.
According to one nonlimiting example, the additional secondary unitary beams are each located in the continuity of and above a second unitary beam.
Furthermore, a third luminous module includes a row of third light sources belonging to the plurality of light sources, and third optical elements, which elements are individually associated with a different one of the third light sources and are configured to receive light from said associated third source and to each transmit a sloped unitary beam formed by a third unitary beam, with a third unitary-beam shape determined by a shape of the third optical elements, the third unitary-beam shape having an upper section provided with a first lateral edge comprising a slope extending to a top of the third unitary-beam shape so that a widthwise dimension of the upper section tends to decrease toward the top; and wherein each of the third unitary beams is associated with one of the second unitary beams so that an upper corner of the upper section of the second unitary beam of said one of the second optical elements coincides with the top of the third unitary beam of the associated third optical element and so that the upper section extends laterally opposite the slope of the third unitary beam of the associated third optical element; and wherein the first unitary beam and the third unitary beam that are associated with a given second unitary beam are offset laterally.
By virtue of the third module, an additional element for generating sloped unitary beams is provided. The delivery of these additional slopes increases the resolution of definition of the border of the envelope of the resultant beam; when it is a question of the cutoff of a low beam, there is then a larger number of potential cutoff edges along the width of the possible complete beam.
Preferably, the shape of the first unitary beam and the shape of the third unitary beam are identical.
Advantageously, the luminous modules each comprise a field optical element.
According to one example, a projecting optical element is common to the luminous modules.
Preferably, control means comprise a low-beam control configuration in which the control means are configured to turn on only a single light source assigned to a slope-comprising unitary beam and to turn on a series of at least one light source assigned to a second unitary beam so as to form a resultant beam section in the lateral continuity of said slope-comprising unitary beam.
In this way, the row of first sources and optionally the row of third sources serves only to generate a single unitary beam at a time, whereas the row of second sources serves to generate the rest of the width of the beam to be formed (in particular that low-beam zone which includes the cutoff). By limiting the superposition of the illumination of the slope-comprising unitary beams and the illumination of the third unitary beams, the localized overbrightness effects that could occur if more beams of slope-comprising shape were simultaneously activated may be limited or even avoided. The low-beam portion generated by the slope-comprising unitary beam and by the second unitary beams may form the low-beam section located in the vicinity of the horizon line (the top portion of the low beam); the rest of the low beam may be formed by a complementary beam, such as a so-called flat beam, i.e. a beam that is straight and uniform, essentially under the horizon line.
Optionally, one of the luminous modules, and particularly advantageously the second luminous module, comprises a row of marking light sources each source of which is associated with a marking optical element. This assembly allows a plurality of marking unitary beams to be generated, said beams being able to be used to produce a discrete projection element below the horizon line, either so as to form a base section of a low beam, or so as to create extra illumination in the base section of a low beam that is moreover generated. For example, a marking-line function allowing a zone in front of the vehicle to be more brightly illuminated may be produced in this way. In this configuration, a series of at least one marking light source may alone be turned on in order to produce a strip of extra brightness in the bottom portion of the low beam.
Optionally, the plurality of sources each comprise at least one light-emitting diode.
Advantageously, at least one among the row of first optical elements, the row of second optical elements, the row of third optical elements and any additional rows of optical elements is produced from a single piece of one material, in particular an optical material such as PMMA (polymethyl methacrylate), the optical elements of a given row being juxtaposed edge-to-edge in the widthwise direction of the beam to be produced.
The invention also relates to a motor-vehicle lighting and/or signalling unit equipped with at least one device such as described above.
Other features and advantages of the present invention will be better understood from the exemplary description and the drawings, in which:
Unless specifically indicated otherwise, technical features described in detail for one given embodiment may be combined with technical features described in the context of other embodiments described by way of nonlimiting example.
In the features described below, terms relating to verticality, horizontality and transversality, or the equivalents thereof, are to be understood with respect to the position in which the lighting module is intended to be mounted in a vehicle. The terms “vertical” and “horizontal” are used in the present description to designate directions, the term “vertical” indicating an orientation perpendicular to the plane of the horizon, and the term “horizontal” indicating an orientation parallel to the plane of the horizon. They are to be understood with respect to the operating conditions of the device in a vehicle. The term “width” is understood to mean a dimension oriented in the horizontal direction and the term “height” is understood to mean a dimension oriented along the vertical. The word “lateral” is understood to mean a position of an element relative to another in the widthwise dimension. The use of these various words does not mean that slight variations about the vertical and horizontal directions are excluded from the invention. For example, an inclination relative to these directions of about + or −10° is here considered to be a minor variation about the two preferred directions.
In the context of the invention, by low beam what is meant is a beam employed in the presence of oncoming and/or followed vehicles and/or other elements (individuals, obstacles, etc.) on the road or close by. This beam has a downward average direction. It may possibly be characterized by an absence of light above a plane inclined 1% downward on the side of oncoming traffic, and above another plane inclined by 15° with respect to the preceding one on the side of traffic driving in the same direction, these two planes defining a cutoff that meets European regulations. The aim of this downward upper cutoff is to avoid dazzling other users present in the road scene in front of the vehicle or on the sides of the road. The low beam, which at one time was generated by a single headlamp, has seen changes, the low-beam function now being able to be coupled with other lighting features that are also considered to be low-beam functions in the context of the present invention.
These functions in particular comprise the following:
In contrast, the function of a basic high beam is to illuminate a large extent of the scene in front of the vehicle, but also to a substantial distance, typically about 200 metres. This light beam, because of its lighting function, is mainly located above the horizon line. It may for example have a slightly ascending optical axis of illumination.
The device may also serve to form other lighting functions via or separately to those described above.
As is known per se, light sources are used. Generally, the present invention may use light-emitting diodes (LEDs) as light sources. It may optionally be a question of one or more organic LEDs. In particular, these LEDs may be provided with at least one chip employing a semiconductor technology and suitable for emitting light of an intensity that is advantageously adjustable depending on the lighting and/or signalling function to be produced. Moreover, the term “light source” is here understood to mean a set of at least one elementary source such as an LED able to produce a flux leading at least one light beam to be generated as output from the module of the invention. In one advantageous embodiment, the exit face of the source is of rectangular cross section, this being typical for LED chips.
The invention comprises a plurality of modules each allowing at least one type of unitary beam to be emitted. They are preferably juxtaposed, i.e. arranged in a horizontal direction of alignment. The term “module” does not mean that the modules are necessarily completely separate units; it simply means that they are units for forming distinct beams; they may share common portions, such as a holder, a projecting optic or electronic elements, such as electronic control elements for example.
“Unitary beam” is here understood to mean an elementary beam that may be generated alone or in association with other unitary beams of the same type (i.e. advantageously of the same shape) and optionally with one or more unitary beams of at least one other type. In one embodiment of the invention, these unitary beams, which are activatable at will, allow, in the desired location in front of the vehicle, a cutoff-containing beam to be produced by association of a slope-comprising unitary beam (providing the shape of a sloped cutoff) and of at least one rectangular unitary beam; the desired location may be modified, in particular depending on curves in the highway lane, by modifying the activated unitary beams while the vehicle is moving. The slope-comprising unitary beam is a beam at least one portion of the lateral border of which is inclined, preferably in a straight line, relative to the horizon line, this inclination being such that the slope-comprising beam makes, in this location, an acute angle to the horizon line. An example of the invention will be given below in which the slope-comprising unitary beams are produced by two modules, the first and third modules, but a single module may be enough.
The modules in question may also be seen from above in
The light sources are therefore each associated with one optical element (one lens 12, 22, 32) so as to form in combination an illuminating unit that produces a unitary beam of a shape defined by the optical element.
The organization of the lenses and of the light sources may be clearly seen in
Advantageously, each optical element comprises or is a lens, and, preferably, a microlens. The microlens preferably has dimensions that are of substantially the same order of magnitude as those of an LED. Preferably, the lens is a spherical lens, a focal point of which is placed behind the LED matrix array. This advantageously allows an enlarged virtual image to be generated behind the LED matrix array, which image is projected by a projecting element to infinity. Alternatively, the element for projecting to infinity may image the exit surface of the lens.
Regarding the first and third modules 10, 30,
The first row illustrates the first unitary beams, each of which forms one pixel 41 of the first beam issuing from the first module 10. This pixel 41 comprises a trapezium-shaped upper section forming the slope-comprising portion of the unitary beam. Preferably, the trapezium is isosceles and/or the slope of at least one lateral side is of 45° relative to the horizon line. The upper section is preferably at least partially and possibly completely projected above the horizon line 40. Another portion of each pixel 41 is generated at the base of the trapezium in the form of a rectangle located in the continuity of the large base of the trapezium. The row of pixels 41 may be symmetric about a central pixel 41 through the middle of which a vertical axis 46 of mean projection passes.
The second row shows pixels 43 of unitary beams of identical shape to that of the pixels 41. These beams are third beams generated by the third module 30. The pixels 43 are nevertheless laterally offset relative to the pixels 41, with an offset pitch 47 advantageously corresponding to the length of the small base, i.e. the upper base, of the trapezium-shaped section of the unitary beams.
The third row shows pixels 42, 44 that are produced by the second module 20. The pixels 42 correspond to the second unitary beams described above and the pixels 44 to pixels of the marking-line function. The latter are preferably rectangles located in the downward continuity of the second-unitary-beam pixels.
The shape of a pixel 41 (which shape is advantageously identical to the shape of the pixels 43) is illustrated in detail in
In low-beam mode, only a single portion of the pixels 41, 42, 43 is turned on so as to produce a cutoff-containing top low-beam portion. One of the pixels 41, 43 will define the cutoff; the other pixels 41, 43 are preferably then turned off. A pixel 42 that is coincident with the first base of the two activated pixels 41, 43 is also activated. Advantageously, at least one other pixel 42, in the continuity of the pixel 42 in question, is also activated, to form a set of activated pixels 42 in the continuity of the cutoff slope defined by the activated pixel 41, 43. This configuration is shown in
It will noted that, advantageously, the lighting device also comprises means for slaving the turn-on of the LED matrix array to a sensor of a path parameter of a motor vehicle. The sensor advantageously delivers an angle of rotation of a steering wheel of the motor vehicle, the path parameter indicating a deviation of a road on which the vehicle is being driven relative to a straight line—such as, in particular, a bend. Thus, the present invention has the advantage of being able to generate a light beam for a low-beam light the cutoff of which follows the path of the vehicle on a winding road, because of a discretization of the beam into successive portions of isosceles-trapezium shape.
Furthermore, the discretization according to the present invention may be adapted to a right-hand drive vehicle and to a left-hand drive vehicle, and even allows, for a given vehicle, a change between left-hand drive and right-hand drive.
The discretization into slope-comprising shapes, and particularly into trapeziums, also allows a high beam that does not dazzle another vehicle to be formed.
Thus, the present invention allows various functions to be performed, such as: a directional low beam, left- and right-hand drive, and a non-dazzling high beam.
It will be noted that the rows of pixels 41, 43 associated with pixels 42 of two-times smaller width increases the resolution with which the cutoff may be placed.
An example of placement of the cutoff-comprising beam zone permitted by the invention is given in
According to one embodiment, the modules 10, 20, 30 may also be used to generate other beams, in a matrix-beam setup. Thus,
The invention is not limited to the described embodiments but encompasses any embodiment according to its spirit.
| Number | Date | Country | Kind |
|---|---|---|---|
| 18 51731 | Feb 2018 | FR | national |
