Luminous motor-vehicle device, and lighting and/or signalling unit equipped with such a device

Abstract

A luminous device including a first row of light sources for generating first unitary beams and a second row of light sources for generating second unitary beams. The first unitary beams have a sloped profile. The first unitary beams and second unitary beams are associated so as to construct a resultant beam provided with a slope and with a section extending laterally from the slope.

Claims

1. 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, wherein the luminous device includes: a first luminous module comprising a row of first illuminating units configured to produce respective first unitary beams, each first unitary beam of the first unitary beams having a first unitary-beam shape that includes an upper section provided with a first lateral edge comprising a slope extending to a top of the upper section of the first unitary beam so that a widthwise dimension of the upper section decreases towards the top; a second luminous module comprising a row of second illuminating units configured to produce respective second unitary beams, each second unitary beam of the second unitary beams having a second unitary-beam shape having a rectangular upper section; wherein each of the first unitary beams is associated with one of the second unitary beams so that an upper corner of the upper section of the one of the second unitary beams coincides with the top of the upper section of the associated one of the first unitary beams and so that the upper section of the one of the second unitary beams extends laterally from the upper corner of the associated one of the first unitary beams opposite the slope of the associated one of the first unitary beams.

2. Device according to claim 1, wherein the upper section of the first unitary-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.

3. Device according to claim 2, wherein the first unitary-beam shape comprises a rectangular lower section in continuity with the second base.

4. Device according to claim 2, wherein the trapezium is isosceles.

5. Device according to claim 2, wherein the width of the first base is equal to that of the upper section of the second unitary beam.

6. Device according claim 5, wherein the height of the upper section of the first unitary beam is equal to the height of the upper section of the second unitary beam.

7. Device according to claim 1, wherein the largest width of the upper section of the first unitary beam is two times larger than the largest width of the second unitary beam.

8. Device according to claim 1, wherein: each first illuminating unit includes 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; 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.

9. Device according to claim 1, wherein the first luminous module is configured to produce, for each first unitary beam, an additional first unitary beam.

10. Device according to claim 9, wherein the additional first unitary beam is located in continuity with and above the first unitary beam.

11. Device according to claim 9, wherein the first luminous module includes at least one row of additional first light sources belonging to the plurality of light sources, and at least one row of additional first optical elements that are each associated with a different one of the additional first light sources, each of the additional first light sources and each associated one of the additional first optical elements being configured to produce the additional first unitary beam.

12. Device according to claim 1, wherein the second luminous module includes at least one row of additional second light sources belonging to the plurality of light sources, and at least one row of additional second optical elements that are each associated with a different one of the additional second light sources, each of the additional second light sources and each associated one of the additional second optical elements being configured to produce an additional second unitary beam.

13. Device according to claim 12, wherein the additional second unitary beam is located in continuity with and above the second unitary beam.

14. Device according to claim 1, including a third luminous module including 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 one of the third light sources and to each transmit a sloped unitary beam as a third unitary beam having 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 thereof 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 one of the second unitary beams coincides with the top of the associated one of the third unitary beams and so that the upper section of the one of the second unitary beams extends laterally opposite the slope of the associated one of the third unitary beams; and wherein the first unitary beams and the third unitary beams that are respectively associated with corresponding second unitary beams are offset laterally.

15. Device according to claim 14, wherein the shape of the first unitary beam and the shape of the third unitary beam are identical.

16. Device according to claim 1, wherein the luminous modules each comprise a field optical element.

17. Device according to claim 16, comprising a projecting optical element that is common to the luminous modules.

18. Device according to claim 1, wherein the light sources are controllable into a low-beam configuration in which only a single light source assigned to the first unitary beam is turned on and a series of at least one light source assigned to a second unitary beam is turned on so as to form a resultant beam section in lateral continuity with the first unitary beam.

19. Device according to claim 1, wherein the plurality of light sources each comprise at least one light-emitting diode.

20. Motor-vehicle lighting and/or signaling unit equipped with at least one device according to claim 1.

Description

(1) Other features and advantages of the present invention will be better understood from the exemplary description and the drawings, in which:

(2) FIG. 1 shows a top view of a section of highway lane and the projection of a low beam in front of a motor vehicle;

(3) FIG. 2 is a perspective view of components of the invention in one embodiment;

(4) FIG. 3 gives a top view of a device according to FIG. 2;

(5) FIG. 4 shows face-on one device portion displaying optical elements taking the form of lenses;

(6) FIG. 4A gives an enlarged example of lens shape;

(7) FIG. 5 illustrates light sources taking the form of LEDs, these sources being associated with the optical elements of FIG. 4;

(8) FIG. 6 schematically shows, in 3 rows, the unitary beams that it is possible to obtain from, in succession, a first module, a third module and a second module, in one embodiment, the third module also producing in this case a beam performing a marking-line function;

(9) FIG. 6A gives a more precise view of a slope-comprising unitary beam able to form a first unitary beam or a third unitary beam;

(10) FIG. 6B provides an example of a second unitary-beam shape;

(11) FIG. 7 shows, on the basis of the possible unitary-beam arrangements in FIG. 6, an example of a cutoff-containing section of a low beam obtained by selectively turning on certain light sources of the modules;

(12) FIG. 8 gives, in projection in a vertical plane in front of the vehicle, an example of a beam envelope resulting from the case in FIG. 7;

(13) FIG. 9 is a projection in a vertical plane in front of the vehicle of a low beam combining the cutoff-containing beam shown in FIG. 8 and an complementary low beam, forming a base of the overall beam;

(14) FIG. 10 is an illustration of complementary unitary beams that the modules may produce, in addition to the first, second and third unitary beams;

(15) FIG. 11 shows how it is possible to modulate the illumination of full-beam headlights, by virtue of selective control of the turn-on of certain light sources.

(16) 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.

(17) 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.

(18) 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.

(19) These functions in particular comprise the following: AFS functions (AFS being the abbreviation of Advanced Frontlighting System), which in particular provide other types of beams. It is in particular a question of the function called BL (Bending Light), which may be subdivided into a function called DBL (Dynamic Bending Light) and a function called FBL (Fixed Bending Light); these functions allow the low beam to be modified whilst the vehicle is being driven and in particular allow the position of the cutoff to be modified in a horizontal direction depending on the driving conditions and in particular on turns in the road. According to one possibility, detection of the angle of rotation of the steering wheel is used to modify the lateral position of the cutoff; it is thus possible to automatically control the direction of the beam emitted by the front headlamps of the motor vehicle depending on an angle of rotation of the steering wheel, this ensuring that the direction of the beam follows the geometry of the road on which the vehicle is being driven, and in particular the path of the vehicle into a corner. the function called the Town Light function. This function widens the low beam while slightly decreasing its range; the function called the Motorway Light function, for its part is used when driving on motorways. This function increases the range of the low beam by concentrating the light flux of the low beam on the optical axis of the headlamp device in question; the function called the Overhead Light function. This function modifies a typical low beam so that sign gantries located above the road are illuminated satisfactorily by means of the low beam; the function called the Adverse Weather Light (AWL) function.

(20) 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.

(21) The device may also serve to form other lighting functions via or separately to those described above.

(22) 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.

(23) 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.

(24) 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.

(25) FIG. 2 gives an example of a device 7 according to the invention with three modules. The first module 10 is intended, in particular in the present case, to produce first unitary beams. It comprises a holder to which lenses 12 forming the optical elements of light sources have been added. The lenses 12 are organized into rows, as are the corresponding sources, as detailed below. A field optical element 13, which may be a biconvex lens, may also be seen in FIG. 2. FIG. 2 also shows a representation of components, which may be similar, for a second module 20: holder 21, lenses 22 and field optical element 23. Likewise, for the third module 30: holder 31, lenses 32 and field optical element 33. Preferably, the three modules 10, 20, 30 share the same projecting optical element (typically a lens).

(26) The modules in question may also be seen from above in FIG. 3. The light produced by a light source of a module is first shaped by a lens of the module, then by the field lens and is lastly projected by the element 8.

(27) 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.

(28) The organization of the lenses and of the light sources may be clearly seen in FIGS. 4, 4a and 5 in particular. In FIG. 4, the front face of the lenses 12, 22, 32 is shown. These lenses are located downstream of the light sources (which are masked in FIG. 4) but borne by electronic boards 14, 24, 34 that may be seen. Regarding the first module 10, two rows of superposed lenses 12 may be seen. Similar rows are formed for the third module. In this example, the second module 20 comprises three rows of superposed lenses 32.

(29) 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.

(30) Regarding the first and third modules 10, 30, FIG. 4a gives an example of the shape of these lenses or more generally of these optical elements. A row of first optical elements 17 is organized in a way ensuring the cutoff slopes. Another row of additional optical elements is also present, for delivering additional beams, in particular for a high-beam portion, in a matrix-beam function. In the illustrated case, the elements 17 and 18 are the same in number and are associated pairwise so as to be vertically aligned; each pair of elements 17, 18 is of rectangular envelope and the element 18, which forms the counter of element 17, here comprises a trapezium-shaped section. They are preferably integrally formed from the same materialsuch as PMMA. The lenses forming the second optical elements of FIG. 4 are generally of simpler shape because the beam shapes are here preferably rectangular (this including square shapes). Advantageously, their width is half the width of the lenses of the other modules (at the very least, the second-unitary-beam lenses 22 are two times less wide than the lenses 12 and 32). It will be seen that this choice of dimensions ensures a particular distribution of the projected beams.

(31) FIG. 5 shows the organization of the light sources of the three modules 10, 20, 30. In alignment with the lenses 12 forming the first optical elements 17, the first module 10 comprises a row of first sources 15 taking the form of laterally aligned LEDs. A row of additional LEDs 16 is in alignment with the row of elements 18. Equivalently, the third module 30 includes a row of third sources 35 and a row of additional sources 36, in association with the row of third optical elements 37 and with the third row of additional optical elements 38, respectively. Since the second module 20 comprises three rows of optical elements in this embodiment, it comprises in alignment three rows of light sources. The row 25 allows the second unitary beams to be produced. The second row 26 produces matrix-beam unitary beams, as in the case of the rows 16 and 36. The row 27 produces unitary beams, in association with the third row of optical elements of the second module, for an additional lighting function, for example a marking-line function. Preferably, the row 27 is located above the row 25, opposite to the row 26. At the very least, the row 25 of the second module 20 has a resolution that is twice (a pitch of half as much between the sources) that of the sources forming the slope-comprising beams.

(32) FIGS. 6 to 11 illustrate the illuminations that it is possible to produce by virtue of the invention.

(33) FIG. 6 shows the result of a projection assuming that all the first, second and third unitary beams are projected simultaneously in addition to all the marking beams.

(34) 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.

(35) 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.

(36) 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.

(37) FIG. 6 furthermore shows that one pixel 42 in two is advantageously aligned with the small base of a trapezium as regards one of the rows of pixels 41, 43 (the row of pixels 41 in FIG. 6) and preferably provision is made for the small base of the trapeziums to coincide with the upper side of the pixel 42 corresponding to this alignment. The other pixels 42 are preferably aligned with the small base of a trapezium of a pixel 43. Preferably, the height of that portion of the pixels 42 which is located above the horizon line 40 is identical to the height of the upper section of the pixels 41, 43. The row of pixels 42 is advantageously symmetric about the line 46. There may be therein nine pixels 41, 43 and nineteen pixels 42.

(38) The shape of a pixel 41 (which shape is advantageously identical to the shape of the pixels 43) is illustrated in detail in FIG. 6a. The upper section 41a is a trapezium the lateral edges 41b and 41c of which are symmetrical. The inclination is here of 45 so that the width of the first base 41d, i.e. the small base, is half the width of the second base 41e, i.e. the large base. The first base 41d forms the top of the shape of the first unitary beam. The pixel 41 here includes a rectangular lower section an upper edge of which is formed by the second base 41e. The base 41e is here located on the horizon line. It is not absolutely necessary according to the invention for the pixel 41 to include a lower section; in particular, the pixel 41 may consist solely of the upper section. The lower section may however soften the transition between the pixel 41 and another beam portion, in particular the edge of a so-called flat beam that is complementary to the pixels 41, 42, 43, which are activated to form a complete low beam. Moreover, the trapezium shape is nonlimiting and recourse could be made to other shapes having at least one slope on one lateral edgefor example a triangle and possibly an isosceles triangle.

(39) FIG. 6b gives an example of a second pixel 42. It is here a question of a square of sides 42a, 42b that are of identical length to the width of the first base 41d. This dimension is preferably also equal to the height of the first pixel 41. This shape defines an upper edge that may coincide with the first base of the trapezium. Generally, provision is made for a corner of the rectangular shape to fit perfectly with one of the ends of the top of the slope-comprising shape (preferably the trapezium).

(40) 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 FIG. 7. The cutoff 48 is given by one of the edges of the trapezium of the activated pixel 41, 43. The rest of the resulting beam is given by pixels 42; there is a certain overlap between the pixels 42 and the activated pixels 41, 43.

(41) 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 linesuch 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.

(42) 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.

(43) The discretization into slope-comprising shapes, and particularly into trapeziums, also allows a high beam that does not dazzle another vehicle to be formed.

(44) 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.

(45) 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.

(46) An example of placement of the cutoff-comprising beam zone permitted by the invention is given in FIG. 8. FIG. 9 gives an example of a complete low beam resulting from the combination of the section obtained in FIG. 8 by the modules 10, 20, 30 with a complementary flat bottom beam.

(47) According to one embodiment, the modules 10, 20, 30 may also be used to generate other beams, in a matrix-beam setup. Thus, FIG. 10 schematically shows the definition of other additional unitary beams with pixels 51, 52, 53. The latter allow a top portion of a complete beam to be generated, for example in order to produce a high beam by simultaneously turning on the pixels 41, 42, 43, 51, 52 and 53. The pixels 51, 52, 53 are in this regard respectively in the continuity of and above a pixel 41, 42, 43. FIG. 10 also shows the marking-line function with the pixels 44 this time directed below the horizon line 40.

(48) FIG. 11 shows the high-beam shape resulting from turning on pixels 41, 42, 43, 51, 52, 53. As shown, all the pixels may not be activated simultaneously in order to isolate one section of the light, taking the form of a vertical strip, for example for an anti-dazzle vignetting function. For example, it is possible to deactivate two adjacent pixels 41, two adjacent pixels 43 and two adjacent pixels 42 in order to not illuminate a zone of width corresponding to two pixels 42. There is furthermore a soft transition between the turned-off zone and the turned-on zone because of the fact that a connecting zone 49 is illuminated only by the pixels 42 from the limit of overlap 50. In this example, the illumination extends 5 above the horizon line. The lateral angular sector is 41 with 23 on the side not upwardly illuminated (here the left-hand side) and 18 on the right-hand side.

(49) The invention is not limited to the described embodiments but encompasses any embodiment according to its spirit.

REFERENCES

(50) 1. Motor vehicle 2. Highway lanes 3. Other lane 4. First lighting zone 5. Second lighting zone 6. Cutoff 7. Device 8. Projecting optical element 10. First module 11. Holder 12. Lenses 13. Field optical element 14. Electronic board 15. First sources 16. Additional first sources 17. First optical element 18. Additional first optical element 20. Second module 21. Holder 22. Lenses 23. Field optical element 24. Electronic board 25. Second sources 26. Additional second sources 27a Row of marking sources 27b. Marking optical element 28. Second optical element 29. Additional second optical element 30. Third module 31. Holder 32. Lenses 33. Field optical element 34. Electronic board 35. Third sources 36. Additional third sources 37. Third optical element 38. Additional third optical element 40. Horizon line 41. First-beam pixel 41a. Upper section 41b. First slope 41c. Second slope 41d. First base 41e. Second base 41f. Lower section 42. Second-beam pixel 42a. Upper corner 42b. First lateral edge 43. Third-beam pixel 44. Marking-beam pixel 46. Median axis 47. Pitch 48. Cutoff 49. Connecting zone 50. Overlap limit 51. Additional-first-beam pixel 52. Additional-second-beam pixel 53. Additional-third-beam pixel