EP2472176A2 - Lighting and/or signalling device, in particular of an automobile - Google Patents

Abstract

The device has an collector mirror for collecting light obtained from a light source e.g. LED, and a non-imaging deflection mirror for producing a first cut-off elementary light beam (20) provided with a cut portion (21) comprising clear and blurred branches (21A, 21B). The elementary light beam is superimposed with a second flat cut-off elementary light beam having a cut portion on a screen perpendicular to an optical axis (Z-Z'). The blurred branch is partially included in the second cut-off elementary light beam.

Description

The present invention relates to a lighting device and / or signaling, including motor vehicle.

Although not exclusively, such a lighting and / or signaling device may be in the form of a motor vehicle light projector, for the purpose of producing for example a coded beam. For such an application, it will be understood that in order to avoid dazzling a motorist arriving in front, it is essential that the projection on the road of the light beam generated by the lighting and / or signaling device does not exceed one predetermined limit.

An already known lighting and / or signaling device is arranged to produce a wide light beam which has a cutoff (namely the transition between a zone illuminated by the beam and a zone not illuminated by said beam, these zones being disposed of both sides of the cut, this transition being realized on a small extent) at once flat and clear.

• une source lumineuse, par exemple sous la forme d'une ou plusieurs diodes électroluminescentes,
• un élément optique de collection lumineuse (ou collecteur), par exemple de type ellipsoïdal, dont un premier foyer est disposé sensiblement au niveau de la source lumineuse de manière à collecter la lumière issue de ladite source,

• une plieuse présentant une surface réfléchissante et un bord de coupure, de manière à recevoir seulement une partie du faisceau lumineux provenant du collecteur et à produire ainsi un faisceau lumineux élémentaire à coupure, et
• un élément optique de renvoi, par exemple de type parabolique, dont le foyer est confondu avec un second foyer du collecteur de manière à projeter vers l'avant le faisceau lumineux élémentaire à coupure ainsi produit.

When it comes to producing a code cut beam (that is to say, whose cut comprises two branches forming between them a non-zero angle, for example an angle between 10 ° and 60 °, especially between 15 ° and 45 °, preferably an angle substantially equal to 15 °) wide, it can be used a lighting and / or signaling device according to that described in the document US 6,966,675 . This device comprises in particular:

• a light source, for example in the form of one or more electroluminescent diodes,
• an optical element of light collection (or collector), for example of ellipsoidal type, of which a first focus is arranged substantially at the light source so as to collect light from said source,

• a folder having a reflective surface and a cutoff edge, so as to receive only a portion of the light beam from the collector and thereby produce a cutoff elementary light beam, and
• an optical return element, for example of parabolic type, whose focus is coincident with a second focus of the collector so as to project forward the elementary light beam cut thus produced.

However, this type of device has a technical limitation in that the cut becomes blurred (fuzzy cut means a light transition between the illuminated area and the unlit area which is carried out over a larger area than the extent of a sharp cut) at the edges, which is undesirable for use on a motor vehicle.

• — un premier faisceau élémentaire à coupure code nette, mais de faible largeur, et
• — un second faisceau élémentaire, plus large, à coupure plate et nette.

Also, in order to produce a code cut beam that is both wide and clean, it is possible to superimpose two elementary beams, namely:

• A first elementary beam with a clean code cut, but of small width, and
• - a second elementary beam, wider, flat and clean cut.

However, with such a device, the flat cutoff portion of the second elementary beam is found in the first elementary beam and, as this flat cutoff portion is sharp, it is visible even while being embedded in the first elementary beam. This is also not desirable for reasons of homogeneity of the overall beam.

The object of the present invention is therefore to provide a lighting and / or signaling device which produces a cut-off light beam whose forward projection (particularly on a screen perpendicular to the optical axis of said device) has a sufficiently sharp delineation and that does not overflow the rest of the road, so that motorists arriving in front are not dazzled, while ensuring that the light intensity distribution of the beam thus produced is otherwise homogeneous.

Another object of the present invention is to provide a lighting and / or signaling device whose design and implementation are both simple and economical.

• un premier faisceau élémentaire présentant, sur un écran perpendiculaire à l'axe optique, une coupure comportant une première branche nette et une seconde branche floue, et
• un second faisceau élémentaire de préférence présentant, sur un écran perpendiculaire à l'axe optique, une coupure,

est remarquable par le fait que la branche floue de la coupure du premier faisceau élémentaire est au moins partiellement incluse dans le second faisceau élémentaire.To this end, according to the invention, the lighting and / or signaling device, especially a motor vehicle, having an optical axis and arranged to produce:

• a first elementary beam having, on a screen perpendicular to the optical axis, a cutoff comprising a first net branch and a second fuzzy branch, and
• a second elementary beam preferably having, on a screen perpendicular to the optical axis, a cut,

is remarkable in that the fuzzy branch of the cutoff of the first elementary beam is at least partially included in the second elementary beam.

Thus, thanks to the invention, a "blur" is generated at the level of the cutoff branch of the first elementary beam, this blur being concealed in the second elementary beam, so that the homogeneity of the overall beam is not disrupted.

A nonlimiting example of distinction between clean cut and fuzzy cut is given below.

et $${\mathrm{\beta }}_{\max }\mathrm{est\; tel\; quel\; G}\left({\mathrm{\beta }}_{\max }\right)\mathrm{=}\max \left(\mathrm{G}\left(\mathrm{\beta }\right)\right)$$

If we consider the function E _η (β), illumination provided by a beam on a screen perpendicular to the optical axis of the module producing the beam, screen located 25 meters from this module, where η is an angle defining a lateral direction by relative to the optical axis of the considered module and β an angle defining a vertical direction with respect to the optical axis of the module, so that E _η (β) is measured at the point of the screen located at 25.tan (η ) meters to the right of the point of intersection of the optical axis of the module and the screen and 25.tan (β) meters above this point, the sharpness and the position of the cutoff of the beam in η are respectively defined by G (β _max ) and β _max where $$\mathrm{BOY\; WUT}\left(\mathrm{\beta }\right)\mathrm{=}\log \left({\mathrm{E}}_{\mathrm{\eta }}\left(\mathrm{\beta }\right)\right)\mathrm{-}\log \left({\mathrm{E}}_{\mathrm{\eta }}\left(\mathrm{\beta }\mathrm{+}\mathrm{0.1}\mathrm{°}\right)\right)$$

and $${\mathrm{\beta }}_{\max }\mathrm{is\; such\; as\; G}\left({\mathrm{\beta }}_{\max }\right)\mathrm{=}\max \left(\mathrm{BOY\; WUT}\left(\mathrm{\beta }\right)\right)$$

It is considered that a cut is sufficiently clear in a zone when G (β _max ) ≥0.13 for all the values of η of the zone. Below this value the cutoff is blurred (or nonexistent).

This distinction between clean cut and fuzzy cut is, for example, of the regulatory type, in the sense that this distinction complies with an official regulation such as No. 112 (Annex 9) on the adoption of uniform technical prescriptions for wheeled vehicles.

According to a particular embodiment, the second elementary beam has a cutoff comprising at least one clean branch, which net branch is substantially coincident, over at least a part of its length, with the net branch of the cutoff of the first elementary beam.

In this case, the cutoff of the second elementary beam may comprise two branches forming between them a non-zero angle, preferably an angle substantially equal to 15 °, said branches being sharp.

According to another particular embodiment, the second elementary beam has a cutoff comprising a first net branch and a second fuzzy branch, the net branches of the first and second elementary beams forming between them a non-zero angle, the fuzzy branch of the cutoff. one of said elementary beams being at least partially included in the other of the beams.

• une source lumineuse,
• un élément optique de collection agencé pour collecter la lumière issue de ladite source,
• une plieuse présentant une surface réfléchissante et un bord de coupure en vue de recevoir seulement une partie du faisceau provenant de l'élément optique de collection et de produire ainsi un faisceau lumineux à coupure, et
• un élément optique de renvoi, agencé pour produire vers l'avant ledit faisceau lumineux à coupure.

Preferably, the part of the device according to the invention capable of producing the first elementary beam comprises:

• a light source,
• a collection optical element arranged to collect light from said source,
• a folder having a reflective surface and a cutoff edge for receiving only a portion of the beam from the collection optical element and thereby producing a cutoff light beam, and
• an optical return element, arranged to produce forward said light beam cutoff.

In this case, according to a first variant, the optical return elements consist of non-imaging optical elements.

According to a second variant, the optical return element consists of an imaging optical element such as a lens.

Preferably, the cutting edge of the folder has, on the side intended to produce the first branch, a main portion, the end of which is in the extension of the side of the cutting edge intended to produce the second branch, and a peripheral portion. , whose end is with said portion an angle corresponding to the angle of inclination of said first branch.

In this case, this part of the device capable of producing the first elementary beam is rotated by a rotation angle of opposite sign and absolute value substantially equal to the angle of inclination of the first branch.

According to a particular embodiment, the projection on a screen perpendicular to the optical axis of the cutoff of the second elementary beam is wider than the projection on the same screen of the cutoff of the first elementary beam.

• la figure 1 est un schéma représentant la projection sur un écran perpendiculaire à l'axe optique d'un faisceau lumineux produit par un module de l'art antérieur ;
• la figure 2 est un schéma représentant la projection sur un écran perpendiculaire à l'axe optique d'un faisceau lumineux produit par un ensemble de deux modules selon la présente invention ;
• la figure 3 représente schématiquement en vue de dessus une forme de réalisation de la première partie du dispositif d'éclairage selon l'invention ;
• la figure 4 représente schématiquement en vue de coupe la première partie du dispositif d'éclairage de la figure 4 ;
• la figure 5 est un schéma représentant la projection sur un écran perpendiculaire à l'axe optique d'un faisceau lumineux produit par la première partie du dispositif d'éclairage des figures 3 et 4 ;
• la figure 6 est un schéma représentant la projection orthogonale d'un faisceau lumineux produit par le module de la figure 4 après rotation ;
• la figure 7 est un schéma représentant la projection sur un écran perpendiculaire à l'axe optique d'un faisceau lumineux produit par la seconde partie du dispositif selon l'invention ;
• la figure 8 est un schéma représentant la projection sur un écran perpendiculaire à l'axe optique du faisceau lumineux résultant de la superposition des faisceaux élémentaires produits respectivement par les première (figure 6) et seconde (figure 7) parties ;
• la figure 9 est un schéma représentant une seconde forme de réalisation de l'invention, intégrant une lentille ;
• la figure 10 est un schéma représentant la projection sur un écran perpendiculaire à l'axe optique d'un faisceau lumineux produit un dispositif d'éclairage selon une autre forme de réalisation de l'invention ; et
• la figure 11 est un schéma représentant la projection sur un écran perpendiculaire à l'axe optique du faisceau lumineux résultant de la superposition des faisceaux produits par les modules des figures 10 et 7.

The figures of the appended drawing will make it clear how the invention can be realized, in which:

• the figure 1 is a diagram showing the projection on a screen perpendicular to the optical axis of a light beam produced by a module of the prior art;
• the figure 2 is a diagram showing the projection on a screen perpendicular to the optical axis of a light beam produced by a set of two modules according to the present invention;
• the figure 3 schematically shows in plan view an embodiment of the first part of the lighting device according to the invention;
• the figure 4 schematically shows in sectional view the first part of the lighting device of the figure 4 ;
• the figure 5 is a diagram showing the projection on a screen perpendicular to the optical axis of a light beam produced by the first part of the lighting device of the figures 3 and 4 ;
• the figure 6 is a diagram representing the orthogonal projection of a light beam produced by the module of the figure 4 after rotation;
• the figure 7 is a diagram showing the projection on a screen perpendicular to the optical axis of a light beam produced by the second part of the device according to the invention;
• the figure 8 is a diagram representing the projection on a screen perpendicular to the optical axis of the light beam resulting from the superposition of the elementary beams produced respectively by the first ( figure 6 ) and second ( figure 7 ) parties;
• the figure 9 is a diagram showing a second embodiment of the invention, incorporating a lens;
• the figure 10 is a diagram showing the projection on a screen perpendicular to the optical axis of a light beam produces a lighting device according to another embodiment of the invention; and
• the figure 11 is a diagram representing the projection on a screen perpendicular to the optical axis of the light beam resulting from the superposition of the beams produced by the modules of the figures 10 and 7 .

In these figures, identical references designate similar technical elements.

The scheme of the figure 1 corresponds to a code beam produced by a lighting device of the prior art, as described for example in the document US 6,966,675 . This device, which has an optical axis Z-Z ', produces a light beam whose projection on a screen (XX'; Y-Y ') perpendicular to the optical axis ZZ' of the device has a cutoff edge in V, this cutting edge having a first branch, located on one side of the screen and which is parallel to the horizontal XX ', and a second branch, on the other side of the screen and which rises to above the horizontal XX 'of a non-zero angle, approximately equal to 15 °.

More specifically, the coded beam produced by this prior art lighting device comprises a central portion 1 with more intense lighting limited by a cutting edge 2 V whose first branch 2A is substantially horizontal, that is to say -dire confused with the axis XX 'of the horizontal plane, and the second branch 2B rises at an angle α relative to the horizontal, that is to say above this axis XX' of the horizontal plane.

The coded beam further comprises a wider portion 3, which overflows on the right and the left of the central portion 1. The wide portion 3 has a horizontal flat cut 4, located at the same level as the first branch 2A (horizontal) of the cut 2 in V. The lighting in part 3 is less intense than in part 1, but sufficient to illuminate the side areas.

The cutoff 2 in V of the central portion 1 of the light beam produced by this type of lighting device has the disadvantage of being fuzzy when one moves away laterally from the optical axis, because of the presence of geometric aberrations. These fuzzy areas are represented on the figure 1 for the two branches 2A and 2B of the cutoff 2, respectively at 5A and 5B. Due to this blur, a luminous flux rises beyond the cutoff edge 2 in V, which may dazzle at least partially motorists arriving in front of the vehicle equipped with this device.

The invention proposes to eliminate these fuzzy areas at the cutoff edge 2 of the beam produced by the lighting and / or signaling device.

• le bord de coupure en V est net, et
• il n'existe aucune zone lumineuse à intensité discontinue.

For this, the lighting device according to the invention is arranged to produce a first elementary beam which, in superposition with a second elementary beam, has the following characteristics:

• the V cut edge is sharp, and
• there is no discontinuous light zone.

The orthogonal projection on a vertical plane of such a beam, produced by a lighting and / or signaling device according to the invention, is represented on the figure 2 . This beam comprises a cutting edge 2 in V whose first branch 2A (left on the figure 2 ) is substantially horizontal and whose second branch 2B (to the right on the figure 2 ) rises at an angle of about 15 ° to the horizontal, these two branches being sharp. In addition, the portion 6 located under the second branch 2B is blurred. The value of this angle α is not limiting and can generally be between 10 ° and 60 °.

According to a first variant of the invention, to obtain an elementary light beam whose cutoff has the characteristics mentioned above in projection on a perpendicular to the optical axis Z-Z ', a first part of the lighting device and / or signaling is schematically represented on the figures 3 and 4 .

This first part M comprises a light source S, constituted for example by at least one incandescent lamp, a Xenon lamp or advantageously by at least one light emitting diode, comprising planar emitters which are located on one and the same plane support in order to facilitate the manufacture of the lighting device and have only one radiator. This source S is arranged to illuminate forwards and upwards. The terms "front" and "rear" are to be understood by considering the normal direction of forward movement of the vehicle equipped with the first part M of the lighting device according to the invention.

A collector mirror R1 is disposed in front of the source S and is turned towards the rear. This mirror R1 comprises a first focus F1 at which (or in the vicinity of) is disposed the center of the source S which illuminates towards the mirror R1, and a second focus F2 located on the optical axis ZZ 'of the first part M of the device.

This first part M also comprises a folder P, whose upper edge P2 constitutes the cutting edge of the beam and passes through the (or in the vicinity of) second focus F2 collector mirror R1.

A reflection mirror R2 is located essentially below the collector mirror R1. The reflective surface of the mirror R2 is turned forward to produce the cutoff output beam. The reflecting mirror R2 has a focus coincident with the (or near the) second focus F2 of the collector mirror R1. The optical axis of the mirror R2 coincides with the optical axis Z-Z 'of the device. The edge of the cut P2 of the folder P also passes through the focus of the mirror R2 (or in its vicinity).

An ice (not shown), of transparent material, can be arranged in front of the elements of the first part M of the lighting device.

The surfaces of the collector mirror R1, the folder P and the deflection mirror R2 are conjugate surfaces. This conjugation may consist in that the collection mirror R1 is designed to transform a spherical wave surface from the center of the source S into an arbitrary wave surface that is reduced to a two-dimensional line P1-P2-P3 . In practice, one can choose for the arbitrary wave surface a toric wave surface, and the line P1-P2-P3 is then in an arc. This solution allows an analytical calculation and offers a parameter that facilitates the horizontal spread corresponding to the major radius of the torus. One can choose the convex line P1-P2-P3, seen from the outside of the projector, which admits a plane of symmetry common with the emitter of the source S. The reflecting mirror R2 is determined to transform this wave surface toric in a cylindrical wave surface of vertical axis admitting any curve for cross section. This curve, which characterizes the wave emerging from the first part M of the device, is chosen so as to compensate at least in part the horizontal inclination of the plane of the source S with respect to the axis ZZ 'of the vehicle, and makes it possible to adjust the horizontal spreading of the beam. This first part M thus makes it possible to create a wide outgoing beam with a clean cut-off line by using the folder with the cutting edge P1-P2-P3, despite the horizontal inclination of the source S.

In order to obtain a V-cut light beam according to the invention with this type of device, it is desirable, in a nonlimiting manner, to use a folder edge of small curvature, at least in the vicinity of the axis, of the side corresponding to the first branch of the cut, and larger curvature on the other side, so that there is a section of the bending edge through which pass little or no radius that are then returned by the output reflector on the side opposite of the optical axis Z-Z '.

So, a first side of the folder P1 (right on the figure 3 ) is substantially rectilinear or of slight curvature, while the second side (left on the figure 3 ) has a first portion P2, close to the center and which extends the right side P1, and finally a zone P4 (or cutting edge portion) which forms a determined angle of inclination with the extension P3 (immaterial) portions P1 and P2, for example 15 °.

The width D of the portion P2 is chosen as small as possible so that the rays passing below the cutoff portion P4 are not returned to the opposite side of the axis ZZ 'to infinity. To determine the value of this width, it is possible to calculate the normal at any point of the collecting reflector by exploiting the following property: a ray coming from the center of the source S and reaching a point of the collector R1 is returned towards the point of the Folder edge P such that the plane normal to the edge of folder in this second point contains the first point.

The normal to the collector R1 at the first point is the bisector of the line connecting the first and the second point and of the line passing through the first point and the center of the source S. In particular, it is possible to calculate the normal to the points from the edge of the collector R1 located in the plane of the source S and deduce therefrom (calculation of the rays reflected for four incident rays coming from each point considered on the collector of the four corners of the source) the horizontal dimensions at the edge of the folder P of the transmitter images formed at these points (for each reflected ray, it is determined the point of the closest folding edge of the line segment carrying the radius which, in general, does not meet the edge of the folder , and the two extreme points from the point of view of their lateral position on the edge of the folder P are preserved). These dimensions correspond to the "widest" images having a given center.

If we consider that at first order the horizontal power of the reflecting mirror R2 is zero (this system is content to project the images to infinity without changing their horizontal angular extent), it is possible to calculate from the radii reflections determined in the manner indicated above, the horizontal angular extent of the images and the position of their horizontal ends (angles of maximum and minimum horizontal algebraic deflection) to infinity.

In addition, for each point of the folder P corresponding to the end of an image, it is also possible to calculate the position at infinity of the center of the images whose center at the folder is the point considered (the direction is the vector of zero vertical component contained in the plane normal to the edge of folder at the considered point).

Thus, from the abscissa of the positions on the edge of the folder P of the ends of the widest image whose center passes through the point considered, as well as extreme horizontal directions after reference to infinity of the widest image whose center passes through the point considered, it is possible to determine the "central" horizontal deviations at the ends (at the level of the folder) of the widest image whose center passes through the point considered .

The abscissae such as the infinite ends of the largest images and the central directions at the ends of these images at the edge of the folder are on the same side (left or right) of the vertical plane containing the optical axis as the point of the Bending edge considered are those for which the folder can be cut to raise light without creating glare.

Referring to Figures 4A and 4B , which respectively represent sectional views of the first part M of the device along the axes ZZ 'and B-B', which respectively correspond to portions PA and PB of the folder P, one can see different possible cases for the paths of the light rays.

The Figure 4A represents the first part M of the device in a section at the portion PA of the cutting edge of the folder P, this portion PA being located at the portions P1 and P2.

The ray i1, coming from a point of the source situated above its center (and thus from the first focus F1 of the mirror R1, itself located at the center of the source S), is reflected along a ray that strikes the PA folder above its lower edge, and thus above the F2 fireplace. This ray is then reflected along a ray which is itself reflected by the mirror R2 according to a descending ray.

The radius i2, emitted from the center of the source S (and hence from the focus F1), is reflected along a radius that tangents the lower edge of the folder PA without being deflected and is reflected by the mirror R2 along a horizontal radius, which corresponds to the cutting edge 11 B of the beam 10 thus produced, which is in the horizontal direction.

The radius i3, coming from a point of the source S situated below its center (and therefore of the focus F1), is reflected by the mirror R1 along a radius which passes below the lower edge of the folder PA, and therefore below the focus F2. This ray is then reflected by the mirror R2 along a descending ray.

Thus, with this portion PA of the folder P, a portion of the right portion of the beam 10, the cutoff 11 B ( figure 5 ) is horizontal and clean.

The Figure 4B represents the first part M of the device in a section at the portion PB of the cutting edge of the folder P, this portion PB being located at the portion P3, itself located in the inclination of the cutting edge of the folder P of an angle α. This portion PB is distinguished in particular from the portion PA (represented in dashed lines on the Figure 4B ) by a different length and possibly by an angle of inclination relative to the mirror R1 different, for example lower.

The radius i4, coming from the same point as the radius i1 of the Figure 4A , is reflected along a radius which, instead of striking the folder PB above its lower edge as the radius i1, tangents said lower edge of the folder PB, without being deflected and is reflected by the mirror R2 following a ascending ray, which corresponds to the cutting edge 11A of the beam 10 thus produced, which rises above the horizontal.

The rays i5 and i6, respectively emitted from the same points as the rays i2 and i3 of the Figure 4A (ie respectively from the center of the source S and a point of the source S situated below its center), are reflected by the mirror R1 according to rays which pass below the lower edge of the PA folder. These rays are then reflected by the mirror R2 in radii respectively horizontal and downward.

Thus, with this portion PB of the folder P, a portion of the left part of the beam 10 whose cutoff 11A ( figure 5 ) rises by an angle α on the horizontal and is likely to be substantially blurred on a portion 12 covering said cut 11A.

The light beam 10, whose projection on a plane perpendicular to the optical axis ZZ 'is represented on the figure 5 , is thus obtained. This elementary beam 10 comprises a cutting edge of which a first branch 11A rises by an angle -α relative to the horizontal and a second branch 11 B substantially horizontal. Furthermore, the area under the branch 11A is blurred when one moves away from the optical axis Z-Z '.

• d'un côté (à gauche sur la figure 6), une première branche 21A, sensiblement confondue avec l'axe X-X' du plan horizontal, et
• de l'autre côté (à droite sur la figure 6), une seconde branche 21 B, nette, qui fait avec l'axe X-X' du plan horizontal un angle non-nul, et plus particulièrement un angle d'inclinaison α sensiblement égal à 15°.

Subsequently, by rotation of the first part M of the device around the optical axis Z-Z ', an angle of rotation - α corresponding in absolute value to the angle of inclination α desired, but of opposite sign , we obtain the elementary light beam 20 of the figure 6 , which has a cutoff 21 whose projection on a screen perpendicular to the optical axis ZZ 'comprises:

• on one side (left on the figure 6 ), a first branch 21A, substantially coincident with the axis XX 'of the horizontal plane, and
• on the other side (right on the figure 6 ), a second branch 21 B, net, which with the axis XX 'of the horizontal plane a non-zero angle, and more particularly an angle of inclination α substantially equal to 15 °.

On this beam 20, the first branch 21A furnishes below it a fuzzy area 22 located completely below the horizontal. In addition, the second branch 21B provides a zone 23 beneath it for at least partially containing another elementary light beam (the beam 30 of the figure 7 described below).

This beam 20 of the figure 6 , superimposed on a flat-cut beam 30 such as that of the figure 7 , the cut 31 has two branches parallel to the horizontal axis, a first branch 31A (left on the figure 7 ) being clean and the second branch 31 B (right on the figure 7 ) being fuzzy, makes it possible to obtain the resulting beam 40 of the figure 8 .

The second part of the lighting and / or signaling device according to the invention, which makes it possible to obtain the flat-cut elementary beam 30 intended to be superposed on the elementary beam produced by the first part M of this same device, is a type of module known to those skilled in the art.

More specifically, one way to achieve this second part is to use the same system as the first part M which produces the elementary beam 20, but by reversing left and right and not turning a given angle around the optical axis Z-Z '.

The resulting beam 40 of the figure 8 , in accordance with the present invention, has a cutoff 41 whose two branches 41A and 41B are sharp, while the beam portions 42 and 43, respectively located under the branches 41A and 41B, are blurred. This gives a beam whose cut V is clear and the light intensity under the cut is homogeneous and without discontinuity, which allows to illuminate as far as possible without exceeding the limits of glare of motorists arriving in the face while ensuring a certain visual comfort. Moreover, the two parts of the device (the first part M of figures 4 and 5 , and the second part that produces the beam of the figure 7 ) which made it possible to obtain the beam of the figure 8 may not consist of any imaging optical element. This makes it possible in particular to make in the elementary beam 30 a sharp cut 31a extending far to the left, whereas with an imaging system, the sharpness at large lateral angles is limited by the aberrations of the projection / return system. In addition, these two parts may be symmetrical to each other, the first part being rotated by a certain angle with respect to the optical axis ZZ 'of the device and not the second part.

According to another embodiment of the invention, a similar result can be obtained by using a projection optical system such as a non-imaging lens. More specifically, as illustrated on the figure 9 , it is possible to realize the first part M of the lighting device and / or signaling according to the invention from a concave reflector R1, a light source (not shown) disposed in the concavity of the reflector R1 to illuminate, and a lens L located in front of the reflector R1 and the light source. The reflector R1 is associated with a folder P, the upper surface of which is reflective for folding the beam coming from the reflector, and has a front end edge of its own to form the cut in the beam produced, this folder P being capable of presenting, for example, a form similar to the folder described above and shown in figures 3 and 4 . In this first part M, the lens L is also determined to give a point of the edge of the folder P, for all the rays contained in the plane perpendicular to the front edge of said folder P at the point considered, an image to the infinite in this plane.

According to another embodiment of the invention, it is possible to use a device whose first V-cut part would produce a beam some of which would go up to the right of the optical axis, without exceeding the V cut. , and that would not be turned around its optical axis. In this way it could be possible to increase the value of the 75R (photometric value defined at a screen perpendicular to the optical axis of the device and located 25 meters from the device, at a point on this screen at 25 centimeters below and 50 centimeters to the right of the optical axis) without creating a contrast line under the V inclination zone (at 15 °).

Such a V-cut module may for example produce a beam as shown in FIG. figure 10 , whose central part 50 has a cutting edge 51 which comprises, on one side (on the right on the figure 10 ), a branch 51 B, net, which rises by an angle α substantially equal to 15 ° above the horizontal, and, on the other side (left on the figure 10 ), a branch 51 A, also clean and horizontal. This beam 50, superimposed on a flat-cut beam 30 such as that of the figure 7 , makes it possible to obtain the resulting beam 60 of the figure 11 , which has a break 61 whose two branches 61A and 61B are sharp, while the beam portion 62, located under the branch 61 B, is blurred.

Claims (9)

Lighting and / or signaling device, in particular for a motor vehicle, having an optical axis (Z-Z ') and arranged to produce: - a first elementary beam (20) having, on a screen perpendicular to the optical axis (Z-Z '), a cutoff (21) comprising a first net branch (21 B) and a second fuzzy branch (21 A), and a second elementary beam (30) preferably having, on a screen perpendicular to the optical axis (Z-Z '), a cutoff (31),
characterized in that the fuzzy branch (21A) of the cutoff (21) of the first elementary beam (20) is at least partially included in the second elementary beam (30). Device according to claim 1, wherein the second elementary beam (30) has a cutoff (31) comprising at least one net branch (31A), which net branch (31A) substantially coincides over at least part of its length, with the net branch (21 B) of the cutoff (21) of the first elementary beam (20). Device according to claim 2, wherein the cutoff (31) of the second elementary beam (20) comprises two branches forming between them a non-zero angle, in particular between 10 ° and 60 °, preferably an angle substantially equal to 15 ° said branches being sharp. Device according to claim 1, wherein the second elementary beam (30) has a cutoff (31) comprising a first net branch (31A) and a second fuzzy branch (31B), the net branches (21A, 31A) of the first and second elementary beams forming between them a non-zero angle, the fuzzy branch of the cut of one of said beams elementary elements (20, 30) being at least partially included in the other of the beams. Device according to one of the preceding claims, wherein the portion (M) of said device capable of producing the first elementary beam (20) comprises: a light source (S), an optical collection element (R1) arranged to collect light from said source, a folder (P) having a reflective surface and a cutting edge (P1, P2, P4) for receiving only a portion of the beam from the collection optical element and thereby producing a cut-off light beam (20); ), and - an optical return element (R2; L), arranged to produce forward said light beam cutoff (20). Apparatus according to claim 5, wherein the return optical element (R2) is a non-imaging element. Device according to one of claims 5 to 6, wherein the cutting edge (P1, P2, P3) of the folder (P) has, on the side intended to produce the first branch (31A), a main portion (P2) , whose end is in the extension (P1) on the side of the cut-off edge intended to produce the second branch (31 B), and a peripheral portion (13B), the end of which forms with said main portion (P2) an angle corresponding to the angle of inclination (α) of said first branch. Device according to the preceding claim, wherein the portion of said device capable of producing the first elementary beam (20) is rotated by an angle of rotation (-α) of opposite sign and of absolute value substantially equal to the angle of inclination (α) of the first branch (31 A). Device according to one of the preceding claims, wherein the projection on a screen perpendicular to the optical axis (Z-Z ') of the cut (31) of the second elementary beam (30) is wider than the projection on the same screen of the cutoff (21) of the first elementary beam (20).

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