EP2390562A2 - Lighting module for headlights of an automobile - Google Patents

Abstract

The module (M) has a reflector (R1) creating spot light via deflection of rays emitted by a photoemissive emitter (1). A lens (L) is arranged such that a profile of the lens is identical to that of a stigmatic reference lens in an intersection point of a control curve (A) with an orthogonal plane, and infinity in a direction through the intersection of the orthogonal plane and a plane of the curve, where the material of the lenses have same refractive index. The reflector and the lens are arranged to form cutoff beam after refraction of the rays deflected by the reflector via the lens.

Description

The invention relates to a lighting module or a lighting unit for a motor vehicle headlamp.

The lighting modules of the state of the art generate a beam for the realization of a light beam, allowing the illumination of the road, alone or in combination with the beam or beams of other modules. They generally comprise a set of associated optical elements to form the beam. Some of these beams are cut-off beams, especially anti-fog or code type. Some modules, generating cut-off beams, use imaging lenses and a folder, ie a reflective plate or horizontal reflective cover, to create the cut.

Two-function lighting modules are also known, in particular according to FR 2 860 280 or after US 7,387,416 .

In some bi-function modules, the folder serves both for the upper cut of the code beam and for the lower cut of the complementary beam, allowing in association with the code beam to make a road beam. The image of the front edge forms an obscure line of separation between the beams given by the two emitters to produce the road beam. To avoid this dark band, it has been planned to make the common cut blurred by defocusing the folder or the lens, or adding patterns to the latter. The fusion of the two beams, effected by fuzzy areas, also leaves a darker area between the two beams. Changes tending to make the cut blurred decrease the value of the maximum intensity of the road beam. These disadvantages are present in the beams produced with the devices of the two patents mentioned above.

The invention aims to achieve simpler projectors design.

• un premier émetteur de lumière plan, pour donner le premier faisceau, cet émetteur étant par exemple formé par au moins un émetteur photoémissif d'une première diode électroluminescente ou LED ;
• une lentille disposée en avant de l'émetteur,
• un premier réflecteur, caractérisé en ce que :
• le premier réflecteur est déterminé de manière à créer dans un plan comprenant le premier émetteur, une tache lumineuse par déviation des rayons émis par le premier émetteur, ladite tache lumineuse étant limitée par une courbe de contrôle constituant le bord avant ou le bord arrière de la tache, la courbe étant contenue dans le plan comprenant le premier émetteur et située en avant du premier émetteur,
• la lentille est déterminée de telle sorte que sa coupe, par un plan orthogonal à ladite courbe de contrôle, soit identique à celle d'une lentille de référence stigmatique entre le point d'intersection de la courbe de contrôle avec le plan orthogonal, et l'infini suivant la direction donnée par l'intersection du plan orthogonal et du plan de la courbe, le matériau de la lentille dudit module et de ladite lentille de référence ayant le même indice de réfraction, le premier réflecteur et la lentille étant agencés de manière à former le premier faisceau à coupure après réfraction par la lentille des rayons déviés par le premier réflecteur.

An object of the invention is a lighting module for a motor vehicle headlamp, able to provide, in particular according to the command applied to it, a first cut-off beam, the lighting module comprising:

• a first plane light emitter, to give the first beam, this emitter being formed for example by at least one emitter light emitting a first light emitting diode or LED;
• a lens disposed in front of the transmitter,
• a first reflector, characterized in that
• the first reflector is determined so as to create in a plane comprising the first emitter, a light spot by deflection of the rays emitted by the first emitter, said light spot being limited by a control curve constituting the front edge or the rear edge of the stain, the curve being contained in the plane comprising the first emitter and situated in front of the first emitter,
• the lens is determined such that its section, in a plane orthogonal to said control curve, is identical to that of a stigmatic reference lens between the point of intersection of the control curve with the orthogonal plane, and infinite along the direction given by the intersection of the orthogonal plane and the plane of the curve, the material of the lens of said module and said reference lens having the same refractive index, the first reflector and the lens being arranged forming the first cut-off beam after refraction by the lens of the rays deflected by the first reflector.

Forwards, we hear forward in the direction of propagation of light, from the light emitter to the lens.

Such a module makes it possible to create a cut-off beam without the aid of a horizontal or vertical cache. The module thus comprises fewer parts.

Another advantage of such a module is that it can also be associated with another reflector to create a bi-function module, which can generate a cut-off beam, for example a code or a beam with a horizontal cutoff, and a second beam cut, which superimposed on the first realizes a beam route. Indeed in this case, the absence of cache, including horizontal, will make it easier to achieve a dual-function lighting module giving a road beam with no dark band between the superimposed beams. It also avoids the presence of necessary mechanisms when the cache is mobile to move from the route function to the code function.

According to a preferred embodiment, the first reflector is determined in such a way that the images of the first emitter, which it provides in the plane of this emitter, meet the control curve while being entirely on the side of the light spot. This makes it possible to improve the sharpness of the cut and to bring the maximum intensity of the first beam towards the cutoff of this first beam.

Preferably, the cut-off beam is a beam with a higher cutoff, the illuminated zone being located below this cutoff.

This is the case, for example, for a code beam or an anti-fog beam.

• un émetteur de lumière plan, pour donner le premier faisceau ;
• une lentille disposée en avant des émetteurs,
• un réflecteur pour dévier les rayons émis par l'émetteur lumineux, caractérisé en ce que :
• la surface réfléchissante du réflecteur est déterminée de telle sorte que, suivant un trajet inverse de la lumière, des rayons lumineux parallèles à une direction donnée, après traversée et déviation par la lentille et réflexion sur le réflecteur, rencontrent l'émetteur en un point donné de l'émetteur,
• la lentille est déterminée de telle sorte que sa coupe, par un plan orthogonal à une courbe de contrôle, soit identique à celle d'une lentille de référence stigmatique entre le point d'intersection de la courbe de contrôle avec le plan orthogonal, et l'infini suivant la direction donnée par l'intersection du plan orthogonal et du plan de la courbe, le matériau de ladite lentille et de ladite lentille de référence ayant le même indice de réfraction, la courbe de contrôle étant située en avant de l'émetteur, le réflecteur et lentille étant agencés de manière à former ledit faisceau lumineux, après réfraction par la lentille des rayons déviés par le réflecteur.

The subject of the invention is also a lighting unit for a motor vehicle headlamp, capable of supplying, in particular according to the command applied to it, a light beam, the lighting unit comprising:

• a plane light emitter, to give the first beam;
• a lens arranged in front of the emitters,
• a reflector for deflecting the rays emitted by the light emitter, characterized in that:
• the reflective surface of the reflector is determined such that, in a reverse path of light, light rays parallel to a given direction, after crossing and deflection by the lens and reflection on the reflector, meet the emitter at a given point of the issuer,
• the lens is determined so that its section, in a plane orthogonal to a control curve, is identical to that of a stigmatic reference lens between the point of intersection of the control curve with the orthogonal plane, and infinite along the direction given by the intersection of the orthogonal plane and the plane of the curve, the material of said lens and said reference lens having the same index of refraction, the control curve being located in front of the emitter , the reflector and lens being arranged to form said light beam, after refraction by the lens rays deviated by the reflector.

Such a lighting unit corresponds to an alternative embodiment of a light beam.

According to an alternative embodiment of the lighting unit, said given point of the transmitter is a point of the front or rear edge of the transmitter. Thus, the beam obtained by this embodiment also makes it possible to create a cut-off beam without the aid of a horizontal or vertical cache.

When this lighting unit is associated with a lighting module according to the invention, said given point of the transmitter is a point of the front or rear edge of the transmitter depending on whether the control curve constitutes respectively the rear edge or the leading edge of the light spot generated by the first reflector and the first emitter. The beam produced by the lighting unit is thus also a cutoff.

The given direction may be inclined relative to the plane of the emitter of the lighting unit.

• en considérant que le module comprend une lame d'épaisseur nulle, présentant une face avant confondue avec sa face arrière, consistant en une fraction de cylindre de génératrices orthogonales au plan de la courbe de contrôle (A), la face avant admettant cette courbe de contrôle comme section droite ;
• en considérant que la face avant comme une étendue verticale infinie ; de manière à ce que suivant un trajet inverse de la lumière, des rayons lumineux parallèles à une direction arbitraire, par exemple choisie dans un plan parallèle au plan de l'émetteur, après traversée et déviation par la lentille, après traversée de la face arrière avant puis de la face avant arrière de la lame, et réflexion sur le réflecteur, rencontrent l'émetteur en un point au voisinage de son centre ; cela permet une alternative de réalisation du réflecteur de l'unité d'éclairage, notamment pour réaliser un faisceau sans coupure ; par voisinage du centre de l'émetteur, on entend un point qui est plus proche de son centre que de ses bords ; préférentiellement, la distance au bord est 3 fois plus élevée que la distance centre ; préférentiellement encore, la distance au bord est 10 fois plus élevée que la distance centre.

According to an alternative embodiment of the lighting unit, the reflector is determined:

• considering that the module comprises a blade of zero thickness, having a front face merged with its rear face, consisting of a cylinder fraction of generatrices orthogonal to the plane of the control curve (A), the front face admitting this curve of control as a straight section;
• considering that the front as an infinite vertical extent; so that in a reverse path of light, light rays parallel to an arbitrary direction, for example selected in a plane parallel to the plane of the transmitter, after crossing and deflection by the lens, after crossing the rear face before and then the front front of the blade, and reflection on the reflector, meet the transmitter at a point near its center; this allows an alternative embodiment of the reflector of the lighting unit, in particular to achieve a seamless beam; near the center of the transmitter is meant a point which is nearer to its center than to its edges; preferentially, the distance to the edge is 3 times higher than the center distance; preferentially, the distance to the edge is 10 times higher than the center distance.

• le module d'éclairage comprend en outre une unité d'éclairage selon l'invention, l'émetteur de cette unité d'éclairage correspondant à un deuxième émetteur du module d'éclairage selon l'invention, le réflecteur de l'unité d'éclairage correspondant à un deuxième réflecteur du module d'éclairage, le premier réflecteur et la lentille étant agencés de manière à former le premier faisceau à coupure, et le deuxième réflecteur et cette lentille étant agencés de manière à former deuxième faisceau lumineux ; la lentille est donc optiquement associée au premier réflecteur et au deuxième réflecteur ; cela permet de diminuer l'encombrement en ayant un module unique pour réaliser deux faisceaux lumineux ; il est ainsi possible de réaliser deux fonctions d'éclairage, par exemple en éclairant le premier faisceau seul, pour une première fonction, et en lui superposant le deuxième faisceau, pour une deuxième fonction.
• les faces réfléchissantes du premier réflecteur et du deuxième réflecteur sont en vis-à-vis ; un tel module est plus compact ; préférentiellement le premier émetteur émet vers le premier réflecteur et le deuxième émetteur émet vers le deuxième réflecteur ; préférentiellement, le module d'éclairage comprend un support commun pour le premier émetteur et le deuxième émetteur, chacun des émetteurs étant situé de part et d'autre de ce support ;

• la surface réfléchissante du deuxième réflecteur est déterminée de manière à ce que le deuxième faisceau lumineux s'ajoute au premier faisceau à coupure pour produire ainsi un faisceau route ;
• le deuxième faisceau présente une coupure basse, de manière à ce que le deuxième faisceau puisse compléter le premier faisceau à coupure, la coupure basse du deuxième faisceau étant adjacente ou parallèle à celle du premier faisceau à coupure, de préférence dans ce cas légèrement en dessous de la coupure du premier faisceau ; comme expliqué plus haut la réalisation de faisceau à coupure sans l'aide de cache permet de superposer ces faisceaux en minimisant leur recouvrement ou en les positionnant de manière adjacente, sans avoir de bande sombre.
• le deuxième réflecteur est situé soit au-dessus du deuxième émetteur lorsque ce dernier émet vers le haut, soit au-dessous lorsqu'il émet vers le bas
• le deuxième émetteur émet vers le haut et le premier émetteur émet vers le bas, soit le deuxième émetteur émet vers le bas et le premier émetteur émet vers le haut ; ceci permet d'améliorer la compacité du module en largeur ;
• le deuxième émetteur est décalé transversalement par rapport au premier émetteur, de manière à ce que le faisceau à coupure produit par le premier réflecteur présente un axe optique différent de l'axe optique du faisceau produit par le second réflecteur ; on peut ainsi rapprocher les émetteurs l'un de l'autre verticalement, sans que la chaleur émise par l'un des émetteurs ne nuise à l'autre émetteur ; lorsque le module d'éclairage comprend un support commun pour le premier émetteur et le deuxième émetteur, chacun des émetteurs étant situé de part et d'autre de ce support, cela permet également de diminuer l'épaisseur de ce support ; de plus un tel mode de réalisation est plus efficace en terme de flux lumineux ;
• le faisceau à coupure produit par le premier réflecteur présente un axe optique différent de l'axe optique du faisceau produit par le second réflecteur ; ceci va permettre de positionner le spot, ou zone d'intensité maximale de l'un des faisceau, en le décalant latéralement par rapport à l'autre faisceau ; on peut par exemple améliorer le rendement du faisceau résultant de la superposition du premier faisceau et du deuxième faisceau en l'étalant par rapport à son spot ;
• la lentille du module d'éclairage est également la lentille de l'unité d'éclairage
• la tache lumineuse se trouve en avant de la courbe de contrôle, laquelle courbe de contrôle est de préférence convexe vue depuis de la lentille, ou rectiligne ; ce mode de réalisation permet de réaliser le module avec une lentille convexe ;
• le premier réflecteur est calculé de manière à ce que pour tout point de la surface réfléchissante du premier réflecteur, un rayon s'appuyant sur la courbe de contrôle et réfléchi en ce point arrive après réflexion sur le coin avant de l'émetteur, situé du côté opposé à ce point par rapport au plan vertical passant par l'axe optique ; dans la présente demande par « rayon s'appuyant sur la courbe de contrôle », on entend un rayon rencontrant cette courbe et contenu dans le plan perpendiculaire à la courbe de contrôle au point d'intersection du rayon considéré et cette courbe ; l'axe optique est par exemple, comme illustré en figure 4, l'axe contenu dans le plan de l'émetteur de lumière, passant par le centre de l'émetteur de lumière et sensiblement perpendiculaire au bord avant de l'émetteur de lumière;
• pour tout point donné de la surface réfléchissante du premier réflecteur (R1): $$\mathrm{d}\mathrm{1}\mathrm{+}\mathrm{d}\mathrm{2}\mathrm{=}\mathrm{K}$$
  
  
  où
  d1 est la distance entre d'une part le coin de l'émetteur situé du côté opposé au point donné, par rapport au plan vertical passant par l'axe optique et d'autre part le point donné,
  d2 est la distance entre le point donné et la courbe de contrôle le long du rayon passant par ce point donné et s'appuyant sur la courbe de contrôle,
  K est une constante ;
• le premier émetteur émet vers le haut, et crée avec le premier réflecteur associé un premier faisceau à coupure dont la zone éclairée est située au-dessous de sa ligne de coupure, et en ce que le module comporte une lame en matériau transparent ayant une face plane supérieure contenue dans le plan du premier émetteur, et une face avant consistant en une fraction de cylindre de génératrices orthogonales au plan de la courbe de contrôle, admettant cette courbe de contrôle comme section droite, de manière à ce que la partie réfractée des rayons atteignant la face supérieure entrent dans la lame ; cette variante permet d'absorber les rayons parasites, notamment lorsque l'émetteur lumineux, par exemple l'élément photoémissif d'une LED, n'a pas de bords nets, ou lorsque des rayons parasites sont émis sur le côté de l'émetteur, notamment le bord de l'élément photoémissif de la LED, ;
• la face arrière de la lame est soit parallèle à la face avant de cette lame, soit correspond à une surface résultant d'une translation de la surface de la face avant de cette lame ; ceci permet de guider les rayons parasites en bas de la lame ;
• l'indice de réfraction du matériau de la lame est supérieur à √2 ; ceci améliore le guidage des rayons parasites dans la lame par réflexion totale ;
• le bord supérieur avant de la lame est confondu avec la courbe de contrôle, et passe donc par le foyer de la lentille dans un plan de coupe vertical ;
• la face d'entrée de la lame est convexe vers l'avant et la face de sortie est parallèle à la face, l'épaisseur de la lame étant constante ;
• le second réflecteur est déterminé de telle sorte que, suivant un trajet inverse de la lumière, des rayons lumineux parallèles à une direction donnée, après traversée et déviation par la lentille après traversée de la face avant puis de la face arrière de la lame, et réflexion sur le deuxième réflecteur, rencontrent le second émetteur en un point de son centre, les faces avant et arrière étant considérées comme d'étendue verticale infinie ; dans ce cas la coupure dans le deuxième faisceau n'est pas réalisée par la forme du deuxième réflecteur mais par la surface supérieur de la lame, qui renvoie les rayons émis par le deuxième émetteur vers le bas, jouant ainsi le rôle de cache horizontal réfléchissant, c'est-à-dire de plieuse ;
• la tache lumineuse dans le plan du premier émetteur se trouve en arrière de la courbe de contrôle laquelle est concave vue depuis la lentille, ou rectiligne ;
• le premier réflecteur comprend une première portion de surface réfléchissante calculée de manière à ce que pour tout point de la première portion de surface réfléchissante du réflecteur située en dehors de l'espace compris entre deux plans passant par les coins arrières de l'émetteur et parallèles à un plan vertical passant par l'axe optique, un rayon s'appuyant sur la courbe de contrôle et réfléchi en ce point arrive après réflexion sur le coin arrière de l'émetteur, situé du même côté que le point donné par rapport au plan vertical passant par l'axe optique ; ce mode de réalisation est particulièrement adapté lorsque le premier émetteur émet vers le bas ; préférentiellement, le premier réflecteur comprend une deuxième portion de surface réfléchissante calculée de manière à ce que pour tout point donné de ladite deuxième portion de surface réfléchissante située à l'intérieur de l'espace compris entre deux plans passant par les coins arrières de l'émetteur et parallèles à un plan vertical passant par l'axe optique, un rayon s'appuyant sur la courbe de contrôle et réfléchi en ce point de ladite deuxième portion de surface réfléchissante, arrive, après réflexion, sur le point du bord arrière de l'émetteur situé dans le plan qui d'une part contient ce point donné de ladite deuxième portion de surface réfléchissante, et d'autre part est parallèle au plan vertical passant par l'axe optique.
• le premier réflecteur est situé soit au-dessus du premier émetteur lorsque ce dernier émet vers le haut, soit au-dessous lorsqu'il émet vers le bas.

According to the first object of the invention, the lighting module according to the invention may also have, in addition to the main features set forth in the preceding paragraph, one or more of the following additional features, any combination of these complementary features, in so far as where they are not mutually exclusive, constituting an advantageous embodiment of the invention:

• the lighting module further comprises a lighting unit according to the invention, the transmitter of this lighting unit corresponding to a second transmitter of the lighting module according to the invention, the reflector of the unit of illumination corresponding to a second reflector of the illumination module, the first reflector and the lens being arranged to form the first cut-off beam, and the second reflector and this lens being arranged to form a second light beam; the lens is thus optically associated with the first reflector and the second reflector; this makes it possible to reduce the bulk by having a single module for producing two light beams; it is thus possible to perform two lighting functions, for example by illuminating the first beam alone, for a first function, and by superimposing the second beam, for a second function.
• the reflecting faces of the first reflector and the second reflector are vis-à-vis; such a module is more compact; preferentially the first transmitter transmits to the first reflector and the second transmitter transmits to the second reflector; preferentially, the lighting module comprises a common support for the first transmitter and the second transmitter, each of the emitters being located on either side of this support;

• the reflective surface of the second reflector is determined so that the second light beam is added to the first cut beam to thereby produce a road beam;
• the second beam has a low cutoff, so that the second beam can complete the first cutoff beam, the low cutoff of the second beam being adjacent to or parallel to that of the first cutoff beam, preferably in this case slightly below the cutting of the first beam; as explained above, making a cut-off beam without using a cache makes it possible to superimpose these beams by minimizing their overlap or positioning them in an adjacent manner, without having a dark band.
• the second reflector is located either above the second emitter when the latter emits upwards or below when emitting downwards
• the second emitter transmits upwards and the first emitter emits downwards, ie the second emitter emits downwards and the first emitter emits upwards; this makes it possible to improve the compactness of the module in width;
• the second emitter is shifted transversely relative to the first emitter, so that the cut-off beam produced by the first reflector has an optical axis different from the optical axis of the beam produced by the second reflector; the emitters can thus be brought closer to one another vertically, without the heat emitted by one of the emitters adversely affecting the other emitter; when the lighting module comprises a common support for the first transmitter and the second transmitter, each of the emitters being located on either side of this support, this also makes it possible to reduce the thickness of this support; moreover, such an embodiment is more efficient in terms of luminous flux;
• the cut-off beam produced by the first reflector has an optical axis different from the optical axis of the beam produced by the second reflector; this will make it possible to position the spot, or zone of maximum intensity of one of the beams, by shifting it laterally with respect to the other beam; for example, the efficiency of the beam resulting from the superposition of the first beam and the second beam can be improved by spreading it with respect to its spot;
• the lens of the lighting module is also the lens of the lighting unit
• the light spot is in front of the control curve, which control curve is preferably convex seen from the lens, or rectilinear; this embodiment makes it possible to produce the module with a convex lens;
• the first reflector is calculated so that for any point of the reflective surface of the first reflector, a ray based on the control curve and reflected at this point arrives after reflection on the front corner of the transmitter, located from the opposite side at this point with respect to the vertical plane passing through the optical axis; in the present application by "radius based on the control curve" means a radius meeting this curve and contained in the plane perpendicular to the control curve at the point of intersection of the radius in question and this curve; the optical axis is for example, as illustrated in figure 4 the axis contained in the plane of the light emitter, passing through the center of the light emitter and substantially perpendicular to the leading edge of the light emitter;
• for any given point of the reflective surface of the first reflector (R1): $$\mathrm{d}\mathrm{1}\mathrm{+}\mathrm{d}\mathrm{2}\mathrm{=}\mathrm{K}$$
  
  
  or
  d1 is the distance between, on the one hand, the corner of the transmitter situated on the opposite side to the given point, with respect to the vertical plane passing through the optical axis and, on the other hand, the given point,
  d2 is the distance between the given point and the control curve along the radius passing through this given point and based on the control curve,
  K is a constant;
• the first transmitter emits upwards, and creates with the first associated reflector a first cut-off beam whose illuminated zone is located below its cut-off line, and in that the module comprises a blade made of transparent material having a face upper plane contained in the plane of the first emitter, and a front face consisting of a cylinder fraction of generatrices orthogonal to the plane of the control curve, admitting this control curve as a cross section, so that the refracted part of the radii reaching the upper face enter the blade; this variant makes it possible to absorb the parasitic rays, in particular when the light emitter, for example the photoemissive element of an LED, does not have sharp edges, or when parasitic rays are emitted on the side of the emitter , in particular the edge of the photoemissive element of the LED,
• the rear face of the blade is either parallel to the front face of this blade or corresponds to a surface resulting from a translation of the surface of the front face of this blade; this helps to guide the parasitic rays at the bottom of the blade;
• the refractive index of the material of the blade is greater than √2; this improves the guidance of parasitic rays in the blade by total reflection;
• the upper front edge of the blade coincides with the control curve, and thus passes through the focus of the lens in a vertical section plane;
• the entrance face of the blade is convex towards the front and the exit face is parallel to the face, the thickness of the blade being constant;
• the second reflector is determined so that, in a reverse path of light, light rays parallel to a given direction, after crossing and deflection by the lens after passing through the front face and the rear face of the blade, and reflection on the second reflector, meet the second emitter at a point in its center, the front and rear faces being considered as infinite vertical extent; in this case the cut in the second beam is not made by the shape of the second reflector but by the upper surface of the blade, which returns the rays emitted by the second emitter downwards, thereby acting as a horizontal reflective cover , that is to say, folder;
• the luminous spot in the plane of the first emitter is behind the control curve which is concave seen from the lens, or rectilinear;
• the first reflector comprises a first reflective surface portion calculated so that for any point of the first reflective surface portion of the reflector located outside the space between two planes passing through the rear corners of the transmitter and parallel at a vertical plane passing through the optical axis, a radius based on the control curve and reflected at this point arrives after reflection on the rear corner of the transmitter, located on the same side as the given point relative to the plane vertical passing through the optical axis; this embodiment is particularly suitable when the first emitter emits downwards; preferably, the first reflector comprises a second reflective surface portion calculated so that for any given point of said second reflective surface portion located inside the space between two planes passing through the rear corners of the transmitter and parallel to a vertical plane passing through the optical axis, a radius based on the control curve and reflected at this point of said second reflective surface portion, arrives, after reflection, on the point of the rear edge of the emitter located in the plane which on the one hand contains this given point of said second surface portion reflective, and on the other hand is parallel to the vertical plane passing through the optical axis.
• the first reflector is located either above the first emitter when the latter emits upwards, or below when emitting downwards.

The invention also relates to a motor vehicle headlamp, comprising at least one module and / or a lighting unit according to the invention. The projector comprises for example a housing closed by a transparent closure glass, this module and / or this lighting unit being inside the space closed by the housing and the ice.

This projector can realize a long-range lighting beam, by means of a lighting unit according to the invention, such as a road beam, and also a cut-off lighting beam, by means of the lighting module. according to the invention.

The lighting unit and the module can also be separate each having its own lens. These lenses can be, according to the invention, very close and be placed adjacent. This gives a uniform off-white appearance.

• l'émetteur est agencé pour émettre un faisceau de rayons lumineux globalement selon une direction transversale,
• le réflecteur est agencé pour collecter l'ensemble de ce dit faisceau de rayons,
• ledit plan orthogonal est orthogonal à un plan vertical, de préférence contenant la direction longitudinale ; par exemple la lentille s'étend verticalement selon sa plus grande direction ; on peut ainsi avoir un agencement d'unité d'éclairage avec un encombrement limité en largeur ; de préférence le faisceau lumineux formé est un faisceau route.

According to an alternative embodiment, the lighting unit according to the invention is intended to be arranged in the motor vehicle headlamp, capable of providing a light beam, such that:

• the transmitter is arranged to emit a beam of light rays generally in a transverse direction,
• the reflector is arranged to collect all of this said ray beam,
• said orthogonal plane is orthogonal to a vertical plane, preferably containing the longitudinal direction; for example, the lens extends vertically in its greatest direction; it is thus possible to have a lighting unit arrangement with a space limited in width; preferably the light beam formed is a road beam.

In the present application, the longitudinal direction corresponds to the direction from the rear to the front of the vehicle, or about the overall direction of emission of the lighting beam of the module or the unit according to the invention. The vertical direction is perpendicular to the longitudinal direction and corresponds to verticality when the unit or module operates in a vehicle on a horizontal road. The transverse direction corresponds to a direction perpendicular to the longitudinal direction and the vertical direction.

• l'émetteur est agencé pour émettre un faisceau de rayons lumineux globalement selon une direction environ verticale,
• le réflecteur est agencé pour collecter l'ensemble de ce faisceau de rayons,
• ledit plan orthogonal est orthogonal à un plan horizontal ; par exemple la lentille s'étend horizontalement selon sa plus grande direction ; on peut ainsi avoir un agencement d'unité d'éclairage avec un encombrement limité en hauteur.

According to an alternative embodiment, the lighting unit according to the invention is intended to be arranged in the motor vehicle headlamp, capable of providing a light beam, such that:

• the transmitter is arranged to emit a beam of light rays generally in a direction that is approximately vertical,
• the reflector is arranged to collect all of this beam of rays,
• said orthogonal plane is orthogonal to a horizontal plane; for example, the lens extends horizontally in its greatest direction; it is thus possible to have a lighting unit arrangement with a space limited in height.

One can also have a single lighting module according to the invention, including the lighting unit. In this case, the lighting module and the lighting unit preferably share the same lens. We thus gain not only homogeneous, but still compact appearance.

The invention also relates to a motor vehicle containing such a projector.

• Fig. 1 est une vue schématique en perspective de trois-quarts arrière et d'en haut d'un module d'éclairage selon l'invention, dans cet exemple un module bi-fonction.
• Fig. 2 est un schéma en perspective, avec parties arrachées, du module en coupe par un plan vertical orthogonal en un point de la courbe de contrôle, pour illustrer la construction de la lentille.
• Fig. 3 est un schéma en coupe verticale d'un module d'éclairage semblable à celui de Fig. 1, avec une section verticale de lentille légèrement différente.
• Fig. 4 est un schéma en plan illustrant le calcul du réflecteur pour l'émetteur code.
• Fig. 5 est un schéma, en plan, illustrant des images de l'émetteur code données par le réflecteur associé.
• Fig. 6 est un schéma en plan illustrant le calcul du réflecteur associé au deuxième émetteur pour le faisceau route.
• Fig. 7 est une illustration de la tache lumineuse produite par le réflecteur code dans le plan horizontal de l'émetteur.
• Fig. 8 est un schéma des courbes isolux du faisceau code dans un plan vertical orthogonal à l'axe du faisceau.
• Fig. 9 illustre les courbes isolux du faisceau produit par le deuxième émetteur pour le faisceau route.
• Fig. 10 est une vue en perspective de trois-quarts arrière et d'en haut d'un module semblable à celui de Fig. 1 mais équipé en outre d'une lame pour éviter la lumière parasite provenant de l'émetteur.
• Fig. 11 est un schéma en coupe verticale illustrant le module de Fig. 10.
• Fig. 12 est une vue en perspective, semblable à Fig. 1, d'un module selon l'invention avec courbe de contrôle rectiligne.
• Fig. 13 est également un schéma en perspective d'un module à courbe de contrôle rectiligne, équipé en outre d'une lame pour éviter la lumière parasite provenant de l'émetteur.
• Fig. 14 est une vue de dessus d'un module selon l'invention avec le faisceau du deuxième émetteur décalé latéralement par rapport au faisceau code.
• Fig. 15 est un schéma des courbes isolux produites par le deuxième émetteur avec le deuxième réflecteur de Fig.14.
• Fig. 16 est un schéma des courbes isolux données par le faisceau code de Fig.14.
• Fig. 17 est un schéma des courbes isolux obtenues par fusion des faisceaux des Fig. 15 et 16.
• Fig. 18 est une vue en perspective schématique, de l'avant et de côté d'un module à lentille concave.
• Fig. 19 est un schéma du module bi-fonction de Fig.18 selon lequel l'émetteur code émet vers le bas tandis que l'émetteur complémentaire pour la route émet vers le haut.
• Fig. 20 est un schéma en coupe horizontale du module de Fig. 19, avec courbe de contrôle concave orientée vers l'avant.
• Fig. 21 est un schéma illustrant le calcul du réflecteur dans le cas d'une courbe de contrôle concave selon Fig. 19, et
• Fig. 22 est un schéma complémentaire du calcul du réflecteur de Fig. 21.
• Fig. 23 est un mode de réalisation particulier selon l'invention vu en perspective.
• Fig. 24 est une vue de face du mode de réalisation de la figure 23.
• Fig. 25 est une vue de dessus du mode de réalisation de la figure 23.
• Fig. 26 est une vue en perspective schématique, de l'avant et de côté d'une unité d'éclairage selon l'invention, avec une lentille s'étendant verticalement.
• Fig. 27 est une vue de face de l'unité d'éclairage selon la Fig. 26.
• Fig. 28 est une vue de côté de l'unité d'éclairage selon la Fig. 26.
• Fig. 29 est un faisceau lumineux réalisé par l'unité d'éclairage illustré en Fig. 26.

The invention consists, apart from the arrangements described above, in a certain number of other arrangements which will be more explicitly discussed hereinafter with regard to exemplary embodiments described with reference to the appended drawings, but which are not in no way limiting. On these drawings:

• Fig. 1 is a schematic perspective view of three-quarter rear and top of a lighting module according to the invention, in this example a dual-function module.
• Fig. 2 is a perspective diagram, with parts torn off, of the module in section by an orthogonal vertical plane at a point of the control curve, to illustrate the construction of the lens.
• Fig. 3 is a vertical sectional diagram of a lighting module similar to that of Fig. 1 , with a slightly different vertical lens section.
• Fig. 4 is a schematic diagram illustrating the calculation of the reflector for the code transmitter.
• Fig. 5 is a diagram, in plan, illustrating images of the transmitter code given by the associated reflector.
• Fig. 6 is a plan diagram illustrating the calculation of the reflector associated with the second transmitter for the road beam.
• Fig. 7 is an illustration of the light spot produced by the reflector code in the horizontal plane of the transmitter.
• Fig. 8 is a diagram of the isolux curves of the code beam in a vertical plane orthogonal to the axis of the beam.
• Fig. 9 illustrates the isolux curves of the beam produced by the second emitter for the road beam.
• Fig. 10 is a perspective view of three-quarter rear and top of a module similar to that of Fig. 1 but also equipped with a blade to prevent stray light from the transmitter.
• Fig. 11 is a diagram in vertical section illustrating the module of Fig. 10 .
• Fig. 12 is a perspective view, similar to Fig. 1 , a module according to the invention with rectilinear control curve.
• Fig. 13 is also a perspective diagram of a rectilinear control curve module, further equipped with a blade to prevent stray light from the transmitter.
• Fig. 14 is a top view of a module according to the invention with the beam of the second emitter offset laterally with respect to the beam code.
• Fig. 15 is a diagram of the isolux curves produced by the second emitter with the second reflector of Fig.14 .
• Fig. 16 is a diagram of the isolux curves given by the beam code of Fig.14 .
• Fig. 17 is a diagram of the isolux curves obtained by fusion of the beams of Fig. 15 and 16 .
• Fig. 18 is a schematic perspective view, from the front and from the side of a concave lens module.
• Fig. 19 is a diagram of the bi-function module of Fig.18 according to which the code transmitter transmits down while the complementary transmitter for the road transmits upwards.
• Fig. 20 is a horizontal cross-sectional diagram of the Fig. 19 , with concave control curve facing forward.
• Fig. 21 is a diagram illustrating the calculation of the reflector in the case of a concave control curve according to Fig. 19 , and
• Fig. 22 is a complementary diagram of the calculation of the reflector of Fig. 21 .
• Fig. 23 is a particular embodiment according to the invention seen in perspective.
• Fig. 24 is a front view of the embodiment of the figure 23 .
• Fig. 25 is a top view of the embodiment of the figure 23 .
• Fig. 26 is a schematic perspective view, from the front and from the side of a lighting unit according to the invention, with a lens extending vertically.
• Fig. 27 is a front view of the lighting unit according to the Fig. 26 .
• Fig. 28 is a side view of the lighting unit according to the Fig. 26 .
• Fig. 29 is a light beam made by the lighting unit shown in Fig. 26 .

Referring to Fig. 1-3 drawings, one can see a bi-function lighting module M for a motor vehicle headlight comprising a first planar emitter formed by the emitter 1 of a first light emitting diode or LED to give a cut-off beam. For example, a fog beam is a beam with an upper cut that is flat and horizontal. The plan Π1 ( Fig. 2 ) of the LED, ie the plane containing the emissive emitter of the LED, is generally horizontal when the module is installed in the vehicle. For example, this plane Π1 can be tilted 0.57 ° (1%) below the horizontal, once mounted on a vehicle. We can then take the flat cut on the horizontal.

A first reflector R1 is associated with the transmitter 1. In the example of Figs. 1-3 , the emitter emitter 1 of the first LED emits upwards and the first reflector R1 is disposed above the first LED. According to the variant of Fig.18-19 which will be described later, the emitter emitter 1 of the first LED emits down and the reflector R'1 is disposed below the LED.

This first reflector R1 is determined so as to create in the horizontal plane of the first emitter 1 a light spot S ( Fig. 2 ) limited by a control curve A which can be chosen arbitrarily. Curve A constitutes the trailing edge of spot S, especially when reflector R1 is above first transmitter 1, as in the case of Fig. 1-3 . As a variant, this curve A may constitute the front edge of the spot S, in particular when the first reflector R'1 is below the emitter, as in the case of Fig. 19 .

The curve A, which is not materialized, is contained in the plane Π1 of the transmitter 1 and is located in front of this transmitter.

The terms "front" and "rear" are to be understood according to the propagation direction of the light which goes from the reflector R1 towards the front, that is to say towards the lens.

As illustrated on Fig. 4 , the reflector R1 for the code is calculated in considering the inverse path of light coming from a lens L so that a radius r based on the control curve A and reflected at a point p of the first reflector R1 arrives on the front corner 1a of the transmitter 1 , located on the opposite side to the point of the input face of the lens L, from which the radius r is derived, relative to the vertical plane Q1 passing through the optical axis. By "radius based on the curve A" is meant a radius meeting the curve A and contained in the plane perpendicular to the curve A at the point of intersection of the radius considered and the curve A. The optical axis is example, as illustrated in figure 4 , the axis contained in the plane of the light emitter and passing through the center of the light emitter and substantially perpendicular to the front edge of the light emitter. The same condition is applied to another point p 'of the first reflector R1 which reflects a radius r' also towards the corner 1a.

où
d1 est la distance entre d'une part le coin (1a, 1b) de l'émetteur situé du côté opposé au point donné (p, pb), par rapport au plan vertical (Q1) passant par l'axe optique et d'autre part le point donné (p, pb),
d2 est la distance entre le point donné (p, pb) et la courbe de contrôle (A) le long du rayon (r, rb) passant par ce point donné (p, pb) et s'appuyant sur la courbe de contrôle (A),
K est une constante.The constancy of the optical path is taken into account for the calculation of the first reflector R1 with for every given point (p, pb) of the reflecting surface of the first reflector (R1): $$\mathrm{d}\mathrm{1}\mathrm{+}\mathrm{d}\mathrm{2}\mathrm{=}\mathrm{K}$$

or
d1 is the distance between on the one hand the corner (1a, 1b) of the transmitter located on the opposite side to the given point (p, pb), with respect to the vertical plane (Q1) passing through the optical axis and d the other hand the given point (p, pb),
d2 is the distance between the given point (p, pb) and the control curve (A) along the radius (r, rb) passing through this given point (p, pb) and based on the control curve ( AT),
K is a constant.

For the part of curve A located on the left side of plane Q1 according to Fig. 4 , the rays are reflected at points of the first reflector R1 such that the point pb to arrive on the front corner 1b located on the opposite side relative to the plane Q1.

The L lens ( Fig. 1-3 ) is conjugated with the first reflector R1 and is determined so that its section Lc ( Fig.2 ) by a plane Vc orthogonal to the control curve A at any point ac is identical to that of a stigmatic reference lens between the point of intersection ac with the plane Vc, and infinity, in the direction given by the intersection Δc of the plane Vc and of the plane Π1 of the curve A.

• un matériau de même indice de réfraction que celui de la lentille L selon la présente invention,
• un tirage D d'une valeur quelconque,
• une face d'entrée quelconque, par exemple plane,
• une épaisseur au centre d'une valeur quelconque.

The reference lens can be easily calculated by those skilled in the art by choosing for this reference lens:

• a material of the same refractive index as that of the lens L according to the present invention,
• a print D of any value,
• any input face, for example plane,
• a thickness in the center of any value.

The draw D, which corresponds to the distance between the focus ac of a vertical section of the lens L and the input face Le of this lens, is constant, and the section of the input face Le by the plane Π1 is constituted by a curve B parallel to the curve A at the distance D. This draw D, the section of the input face Le, and the thickness at the center for this section are identical to those of the reference lens.

In the example shown, the curve A is located in a horizontal plane which is that of the LED 1. The plane Vc is therefore vertical and orthogonal to the tangent to the curve A at the point ac. The intersection Δc is horizontal and itself orthogonal to the tangent to the curve A at the point ac. A light ray r1 reflected by the first reflector R1 and passing through the point ac leaves the lens L along the radius e1 parallel to Δc. The ray r1 comes from the front edge of the transmitter 1. The other light rays of the transmitter 1 will come from a point situated behind the one that provides the ray r1 so that the reflected ray r2 will be above the radius r1 so as to meet the plane Π1 in front of the line A, in the spot S. This ray r2 will emerge from the lens L according to an emerging ray e2 inclined downwards with respect to the direction Δc and to the horizontal plane Π1.

The lens L makes it possible to spread the beam because of the convex shape of the curve A towards the front; the shape of the lens L is substantially toric with a convex exit face Ls.

The beam given by the set of the first transmitter 1, the first reflector R1 and the lens L is a horizontal cut beam, the cut line being determined by the curve A, which has no material thickness, and the beam is located below the cutoff line since the rays such as e2 are inclined downwardly relative to the horizontal plane Π1.

As illustrated on Fig. 5 , the images such as 11, 12 of the LED 1 given by the different points of the first reflector R1 are located in front of the curve A. One of the vertices of the rectangular image is in contact with the curve A.

The device thus formed creates a flat-cut beam whose horizontal distribution (and in particular the width) is controlled by the curve of plane control A initially chosen. Depending on the configuration considered, the light may be above the cutoff line, the first emitter 1 emitting upwards and control curve A constituting the leading edge of the light spot, or first emitter 1 emitting downwards and control curve A constituting the trailing edge of the light spot, or below the cut-off line, the first emitter 1 emitting upwards, and control curve A constituting the trailing edge of the spot S, or emitter 1 emitting down and control curve constituting the front edge of the spot of light.

Then consider a second horizontal plane transmitter 2 having an emission direction opposite that of the first transmitter 1 and offset vertically with respect to the first transmitter 1 in its own transmission direction. This second emitter 2 can also be shifted in view from above with respect to the first emitter 1 in order to facilitate the physical implantation of the sources, namely closer to or further from the lens L than the first emitter 1.

The second planar emitter 2 is formed by the photoemissive element of a second LED and is intended to contribute to the establishment of a second beam which, in combination with the beam of the first emitter 1, gives a road beam.

In the case of Fig. 1-3 where the first LED emits up, the second LED emits down as illustrated on Fig. 3 . The LEDs 1, 2 are arranged on the two opposite parallel faces of the same support 3, the second LED 2 being located behind the LED 1.

A second reflector R2 is located below the LED 2 to provide the beam that is added to the cut beam of the first reflector R1 to produce the road beam. The second reflector R2, the emitter 2 and the lens L, form a variant of the lighting unit according to the invention.

We choose an arbitrary horizontal direction.

We consider all the light rays parallel to the chosen direction ( Fig. 6 ) reaching the exit face Ls of the lens L calculated previously, and determining a reflector R2 located below or above the second emitter 2, in its direction of emission, such as the rays considered, after deflection by the lens L and reflection on the second reflector R2, meet the second transmitter 2 at a point on its edge, front or rear, depending on the configuration of the system. The edge on the same side as in the case of the first emitter 1 is used, ie in this example the edge forward in the direction of propagation of light outside the module.

The second reflector R2 is determined as illustrated in Fig. 6 such that, in a reverse path of light, rays r3, r4 parallel to the arbitrary direction chosen in a plane parallel to the parallel planes of the emitters 1, 2, after deflection by the lens L and reflection at a point m3 , m4 of the second reflector R2, meet the second emitter 2 at a point 2a, 2b of its front edge, preferably located at an angle of the second emitter 2. Always considering the reverse path of the light, the ray reflected last by the point m3 of the reflector R2 arrives on the corner 2a of the second emitter 2 situated on the opposite side to the point m3 with respect to the vertical plane Q1 passing through the optical axis. For the radius r4 which is on the other side of this plane Q1 with respect to r3, the ray reflected by m4 comes from the corner 2b situated at the other end of the front edge of the second emitter 2.

The plane Π2 orthogonal to the r3, r4 rays is a wave surface for the parallel beam coming out of the lens L and coming from the reflector R2. The second reflector R2 is calculated by expressing that the optical path is constant for rays such that r3, r4 between the plane Π2 and the point 2a, 2b of the second emitter 2 from which the radius originates.

The device thus formed creates a concentrated beam whose light is located on the opposite side (vertically) of the horizontal cut of the beam created with the first transmitter 1.

The parallel to the control curve A initially chosen, at a distance equal to the sum of the draft D of the stigmatic lens of construction and its thickness in the center, has no cusp point or double point. This parallel corresponds to the section of the exit surface of the lens by the plane Π1 of the transmitter 1.

• dans le cas où la tache de lumière dans le plan du premier émetteur 1 est située derrière la courbe de contrôle A, celle-ci ne doit pas être convexe dans la direction de la lentille pour obtenir une coupure plate ;
• dans le cas où la tache de lumière dans le plan du premier émetteur 1 est située en avant de la courbe de contrôle A, celle-ci ne doit pas être concave dans la direction.

According to an alternative embodiment:

• in the case where the spot of light in the plane of the first emitter 1 is located behind the control curve A, it must not be convex in the direction of the lens to obtain a flat cut;
• in the case where the spot of light in the plane of the first emitter 1 is located in front of the control curve A, it must not be concave in the direction.

The properties set out above make it possible to establish the equations of the surfaces of the reflectors R1, R2 and of the lens L, as a function of the control variables: curvature, pulling, thickness at the center, and refractive index of the material of the stigmatic lens. of construction, and two additional arbitrary quantities of the optical path type, such as the distance from the bottom of the reflector to the source. The calculations are based on considerations of constancy of the optical path between the points of the control curve A and the appropriate points of the edge of the first emitter 1 and, for the second emitter 2, between the appropriate points of its edge and a surface d plane exit wave, direction previously chosen.

Fig. 7 is an illustration of the light spot S which is produced in the horizontal plane of the first emitter 1. This light spot S could be observed after removal of the lens L and establishment of a horizontal screen in the plane of the first emitter 1. The trailing edge of the spot S is formed by the curve A, while the front limit B corresponds to the intersection of the entrance face of the lens Le by the horizontal plane of the spot S.

Fig. 8 illustrates the isolux curves of the first horizontally cut beam obtained with the first LED (first emitter 1), the reflector R1 and the lens L. The set of isolux lines of the beam F1, that is to say its illuminated zone, is located under the horizontal cut, below the horizontal line H of cut.

Fig. 9 illustrates the isolux curves of the beam F2 obtained with the second LED 2, the reflector R2 and the lens L, this set corresponding to the previously described lighting unit. The isolux curves of the beam F2 are located above the cut line H.

Two possible improvements are now being considered. In these two improvements, the second reflector R2, the emitter 2 and the lens L, form light unit variants according to the invention.

Improvement 1

For the construction of the second reflector R2 associated with the second emitter 2, a direction of the emerging radii r3, r4 which is not horizontal and in particular inclined upwards is chosen if the beam created by the first emitter 1 is situated above its cutoff line. or inclined downwards if this beam is below its cutoff line. This arrangement makes it possible to guarantee, already for a low angle of inclination, a few degrees, a good fusion of the beams created by the two emitters 1, 2.

Improvement 2

Fig. 10 and 11 show a module of the same type as that of Fig. 1-3 and which corresponds to the case where the first emitter 1 radiates upward and creates a beam located below its horizontal cutoff line ( Fig. 1-4 ).

Some LEDs may have weakly bright areas in the vicinity of the edges of their emitters 1. If an LED of this type is used to make the first emitter 1, noise appears above the cut, which, depending on the function performed ( and in particular the horizontal spreading of the beam) can decrease the quality of the beam more or less strongly (these parasites potentially correspond to dazzling).

In the case where the LED can not be changed for a better model, we can add to the system a blade of transparent material 4 ( Fig.11 ) having an upper planar face 4a contained in the plane of the first emitter 1 and a front face consisting of a cylinder fraction of vertical generators admitting the control curve A for cross section. The rear face, located closer to the transmitter 1 than the front face, may be the result of a translation of the front face or a parallel surface.

The upper front edge of the blade 4 coincides with the control curve A, and therefore passes through the focus of the lens L in a vertical section plane. The input face 4e of the blade 4 is convex towards the front and the exit face 4s is parallel to the face 4e, the thickness of the blade being constant.

In the absence of parasites, no ray emitted by the first emitter 1 and reflected by the associated reflector R1 reaches this blade 4.

On the other hand the parasitic rays such as 5, shown in dashed lines, reach the upper face 4a of the blade and undergo both a partial reflection and a refraction. The radius 5r, reflected by the reflector R1 from the radius 5, falls on the upper face 4a of the blade 4 behind the front edge and therefore behind the focus of the lens for the plane considered. The portion 5r2 reflected by the face 4a reaches the lens L and is returned along the radius 5s in the beam, below the cut due to the phenomenon of "folding". If the refractive index of the material of the blade 4 is greater than √2, the refracted portion is guided downwardly of the blade 4 where a means is provided for it to be absorbed.

Such a device thus ensures the absence of parasites above the cut. The fraction of energy lost by guidance is negligible. For example 0.58 lm for an LED at 600 lm - with 380 lm in the beam beyond the lens, in one of the exemplary embodiments.

In this variant, a large part of the rays reflected on the second reflector R2 associated with the second emitter 2 meets the transparent plate 4. It is then preferable, when calculating the second reflector R2 to take account of the deviations (or, which is equivalent , of the modification of optical path) introduced by this blade 4. In this calculation, we neglect the upper face of the guide and we consider its front face as infinite vertical extent; in addition, we consider a single source point that must meet the building radius, located in the center of the second transmitter 2.

The second reflector R2 is determined so that, along a reverse path of light, light r3 r4, r4 parallel to an arbitrary direction, chosen in a plane parallel to the parallel planes of the emitters 1,2, after crossing and deflection by the lens L, after crossing the rear face and then the front face of the blade, and reflection on the second reflector R2, meet the second emitter 2 at a point in its center, the front face being considered as an infinite vertical extent and considering a given thickness of blade 4.

The upper face 4a of the guide 4 then acts as a folder in total reflection and creates a partial low cut in the concentrated beam. The thicker the guide 4, the fewer rays passing above the guide, hence the light below this partial low cut, but the less the second reflector R2 is extended, since it is physically limited by the face back of the guide 4.

Variant

It is possible to obtain a variant with the two reflectors R1, R2 without a transparent plate, where the second reflector R2 is constructed by means of the calculations carried out for the improvement 2, applied to the case of a guide 4 of zero thickness. The second reflector R2 and the second emitter 2 thus give an intense uninterrupted beam which can be used for a road-type function and which has a large overlap with the cut-off beam created by the first emitter 1. sending additional light rays under the cut, it has the advantage of allowing to obtain a beam much more intense than the image alignment beam. In addition, it is possible to limit this quantity of rays sent under the cut by the second reflector R2 by shifting the second emitter 2 towards the rear.

This variant is compatible with improvement 1 above. The second reflector R2, the emitter 2 and the lens L, form a variant of the lighting unit according to the invention.

Fig. 12 shows in perspective, similar to Fig. 1 , a module M1 according to the invention, in which the control curve A is rectilinear horizontal so that the lens L1 has an entry face L1e which is flat, vertical. The second reflector R2, the transmitter 2 and the lens L1, form a lighting unit variant according to the invention.

Fig. 13 shows, similarly to Fig. 12 , an M2 module with a control curve formed by a straight line, and furthermore equipped with a blade 4.1 with parallel vertical plane faces adapted to avoid the parasites due to rays coming from the edges of the plane emitter 1. The second reflector R2 , the transmitter 2 and the lens L1, form a lighting unit variant according to the invention.

Referring to Fig. 14 , we can see, in plan, a module M3 with beam shifted laterally. The cut-off beam produced by the reflector R1 has an optical axis Y1 different from the optical axis Y2 of the beam produced by the reflector R2 for the road beam. The lateral offset angle α of the Y2 axis beam relative to the Y1 axis of the cut beam can be 14 °. The entire module M3 is rotated by the same value, in the opposite direction, so that the optical axis Y2 is parallel to the axis of the vehicle. The second emitter 2 is shifted laterally in the opposite direction to the offset of the beam. For example -10 mm in the transverse direction of the vehicle, before rotation of the module to optimize the efficiency of the road beam. The second reflector R2, the emitter 2 and the lens L, form a variant of the lighting unit according to the invention.

Fig. 15 is a diagram of the isolux curves of the beam F'2 obtained with the second transmitter 2 of Fig. 14 , which is located on either side of the horizontal line of cut.

Fig. 16 illustrates the isolux curves of the beam F'1 obtained with the first transmitter 1 of Fig. 14 , which is shifted laterally with respect to the beam of Fig. 15 .

Fig. 17 illustrates the isolux curves of the beam resulting from the fusion of the wide-width beam F'1 for the code and the road complement F'2.

To improve the beam obtained by melting the two elementary beams, the F'2 complement "road" beam should be placed with its maximum located at 1% higher than the cutoff line.

Referring to Figs. 18 and 19 , we can see a module M4 according to the invention in which the LED 1 for the cut-off beam emits downwards and the first associated reflector R'1 is located below the LED 1. The LED 2 for the road beam emits upwards and the second associated reflector R'2 is located above this emitter 2. The second reflector R'2, the emitter 2 and the lens L, form a variant of the lighting unit according to the invention. invention.

The control curve A '( Fig. 20 ) is concave towards the lens L '. The exit face The s of this lens is also concave as visible on Fig. 18 .

The reflector R'1 is determined so as to create a spot of light S '( Fig. 20 ) located behind the control curve A 'and admitting this curve as the front limit. The rays such as 6 coming from the rear edge of the first emitter 1 are reflected at 6a by the reflector R'1 so as to rely on the curve A 'which corresponds to the focus of the stigmatic lens in a vertical sectional plane, similar to what was explained about Fig. 3 .

Under these conditions, the rays coming from points situated in front of the rear edge of the transmitter 1, after passing through the lens L ', will be inclined downwards on the horizontal plane. The beam produced by the first transmitter 1 and the first reflector R'1 will be a cut-off beam located below the cutoff line.

The rear edge of the second emitter 2 emits rays which, after reflection by the second reflector R'2, rely on the curve A 'or are located behind this curve. The other points of the second emitter 2 will give rays which, after passing through the lens L ', will be directed upwards relative to the horizontal.

In the case where the lens L 'is concave, as illustrated on Fig. 18 , with the emitter coding 1 emitting downwards, the first reflector R'1 is determined as illustrated in FIG. Fig. 21 in order for the light rays r'4, r'6 considered along the inverse path of the light, to converge towards the rear corners 1c, 1d of the plane rectangular emitter 1, on the same side of the vertical plane Q'1 passing through the optical axis that their point of intersection m'4, m'6 with the reflector R'1, in the case where m'4, m'6 is outside the space between two planes Q2 and Q3 parallel to Q '1 and passing through the back corners of the transmitter 1.

When the intersection m'5 of a radius r'5, considered along the inverse path of light, with the reflector R'1 is located between the planes Q2 and Q3 of the figure 22 , it reaches the point 1e of the rear edge of the transmitter located in the plane parallel to Q'1 containing m'5.

• les deux extrémités du segment arrière de l'émetteur, et
• le point de la droite support de ce segment de même projection sur cette droite que le point du réflecteur recherché.

To determine a point of the reflector, the equation describing the constancy of the optical path (according to Fermat's theorem) of the curve A 'at the corresponding source point of the transmitter is solved for three possible cases of hypothetical source points:

• both ends of the back segment of the transmitter, and
• the point of the line of support of this segment of the same projection on this line as the point of the reflector sought.

Only one of the three solutions found then complies with the conditions set out above (with respect to the r'4 and r'5 rays).

Other variants with cut-off beam located above the cut-off line are possible.

In the case of Figs. 1-3 , so that the first emitter 1 gives a cut-off beam located above the cutoff line, the first reflector R1 is determined so that it gives a spot of light located behind the control curve A, instead of to be ahead in the example that has been described.

In the case of Figs. 18 and 19 to obtain a cut-off beam located above the cutoff, the first reflector R'1 is determined to give a spot of light ahead of the concave control curve A '.

Whatever the solution adopted, a cut-off beam is obtained by controlling only the ignition of the first transmitter 1, and a road-type beam by controlling the ignition of the two transmitters 1 and 2. The fusion of two beams is effected then in good conditions, without presence of a dark band between them since there is no hardware edge of folder. This fusion takes place without the need to control a mechanical movement of a folder.

The invention provides a module with a toric lens rather than elliptical. It is thus possible to assemble several similar modules with toric lenses, in continuity of tangency of the surfaces of the lenses.

The module produces a wide beam with clean cut, and does not have a complex form of brake to compensate, still partially, the aberrations of the lens.

There is no risk of focusing sun rays on the surface of the reflector or LEDs, resulting in degradation of these elements. Indeed, the lens is non-imaging, that is to say that it does not form the image of an object located at its focus in any real or virtual plane, even when the size of the object tends towards 0. Good yields for the road beam and for the coded beam are obtained with respect to more conventional folding solutions. There are no hard parts to make.

According to the present invention, it is possible to use a first lighting module according to the invention with a lighting unit according to the invention, said module and said unit being two sets of distinct optical systems, with a separate lens. This use can be performed in the same vehicle headlight, the lighting unit and the lighting module being placed in the housing of the projector. The casing is preferably closed, preferably by a transparent closure glass.

For example, Figures 23 to 25 illustrate the lateral juxtaposition of a first lighting module Ma with a lighting unit Mb, each having its own lens, respectively La and Lb.

The first lighting module Ma may be a lighting module according to the invention. In the example shown in Figures 23 to 25 , it corresponds to a module such as the one illustrated in figure 1 , but without the reflector R2 or the transmitter 2. The module Ma comprises a first reflector R1, deviating the rays emitted by an LED 1 to the lens La, to create a first beam in a global direction X1.

The first reflector R1 and the lens La have a determined shape and are arranged as the first reflectors and the lenses of the lighting modules according to the present invention described above. Other lighting modules according to the invention could therefore be used, with or without a lighting unit according to the invention, such as for example a module such as that of my figure 4 , with or without the second reflector R2 and the second emitter 2.

The lighting unit Mb may be a lighting unit according to the invention. In the example shown in Figures 23 to 25 , it corresponds to a lighting unit such as that illustrated in figure 1 , without first reflector R1 or first transmitter 1. The lighting unit Mb comprises a second reflector R2, deflecting the rays emitted by an LED 2 to the lens Lb, to create a second beam in a global direction X2.

The second reflector R2 and the lens Lb have a specific shape and are arranged as the second reflectors and the lenses of the lighting modules according to the present invention described above. Other lighting units according to the invention could therefore be used.

Alternatively, the lighting module may be a module such as that M4 shown in FIG. figure 18 , without the second reflector and without the second transmitter. The lighting unit can then be a unit such as R'2, 2, L ', illustrated in FIG. figure 18 , without the first reflector and without the first transmitter.

In the Figures 23 to 25 the lighting module Ma and the lighting unit Mb are aligned transversely, but they could also to be superimposed. The lenses La and Lb can be side by side with little space between them, as illustrated. They can also be adjacent; as the lenses are close in shape, or even identical, it is then possible to have a very homogeneous appearance, or even to place them in continuity from one another transversely, to give a unique lens impression.

In the example shown in Figures 23 to 25 , in a nonlimiting manner, the first transmitter 1 and the second transmitter 2 are mounted on separate supports 3 'and 3 ".The first cut-off beam and the second beam may be beams as previously described and be combined as previously described. The arrangement of the first reflector R1 with respect to the second reflector R2 and / or the offset between the first transmitter 1 and the second transmitter 2 may be as described above.

The invention also covers vehicle projectors using lighting modules according to the invention but without a lighting unit according to the invention, for example a module such as the lighting module Ma previously described and illustrated, in a non-transparent manner. limiting, in Figures 23 to 25 . This module can for example be used to produce a first cut-off beam. It is then possible to have a second module, for example already known, to achieve an additional route beam, either in addition or alternatively to the illumination of the first module.

Similarly, the invention also covers vehicle projectors using lighting units according to the invention but without a first reflector, for example a unit such as the lighting module Mb previously described and illustrated, without limitation, in Figures 23 to 25 . This module can for example be used to make a road beam. It is then possible to have a lighting module, for example already known, to generate a cut-off beam, the lighting unit being switched on either in addition or alternatively to the illumination of the module.

The invention also covers an M5 lighting unit, as illustrated in FIG. Fig. 26 to FIG. 29 . This lighting unit is a lighting unit according to the present invention. For example, this unit is similar to the Mb lighting module previously described and illustrated, without limitation, in Figures 23 to 25 . However, this lighting unit M5 is intended to be mounted in the projector by being rotated 90 ° along a longitudinal axis relative to the mounting of the lighting unit Mb Figures 23 to 25 .

• l'émetteur 2 est agencé pour émettre un faisceau de rayons lumineux globalement selon une direction transversale,
• le réflecteur R"2 est agencé pour collecter l'ensemble de ce faisceau de rayons,
• ledit plan orthogonal Vc est orthogonal à un plan vertical, de préférence contenant la direction longitudinale.

Thus, the lighting unit M5 is intended to be arranged in the motor vehicle headlamp, capable of providing a light beam, so that:

• the emitter 2 is arranged to emit a beam of light rays generally in a transverse direction,
• the reflector R "2 is arranged to collect all of this beam of rays,
• said orthogonal plane Vc is orthogonal to a vertical plane, preferably containing the longitudinal direction.

On the figure 26 , an orthonormal marker has been placed to schematically represent the vertical "V", a transverse direction "T", and a longitudinal direction "L".

It is thus observed that the planes according to which the lens section L "is stigmatic, as previously described, are always orthogonal to a vertical plane In other words, the lens L" extends vertically, in its greatest direction . In the case of a toric lens, the guide curve is vertical.

According to an alternative embodiment, this lighting unit M5 is made to generate a beam with a cutoff, as previously described for the formation of the complementary road beam. This makes it possible to have a vertical cut beam when it is placed in the projector, since the lighting unit is turned 90 ° compared to the units described in the other modes.

According to another variant embodiment, this lighting unit M5 is designed so as to be able to generate an unbroken beam, as previously described, while arranging the lens vertically. Surprisingly, the lens makes it possible to generate a road beam, as illustrated in FIG. figure 29 while the lens L "extends vertically The reflector R" 2 extends on either side of the horizontal plane passing through the LED 2. The reflector R "2 forms a concavity oriented transversely to the vehicle, for example the reflector R "2 is formed of a half shell, located approximately integrally on one side of the vertical and longitudinal plane passing through the LED 2.

The advantage of this lighting unit M 5 is that it allows installation in a projector with a small transverse size. It also makes it possible to follow a curve in a vertical plane, and thus to realize road lights with a strong return on the top of the wing of the vehicle. It also allows a different orientation for reasons of style.

Claims (19)

A lighting module for a motor vehicle headlamp, capable of providing a first cut-off beam, said lighting module comprising: a first emitter (1) of plane light, to give the first beam; a lens (L, L1, L ', La) disposed in front of the transmitter, a first reflector (R1, R'1), characterized in that the first reflector (R1, R'1) is determined so as to create in a plane comprising the first emitter (1), a light spot (S, S ') by deflection of the rays emitted by the first emitter, said light spot being limited by a control curve (A, A ') constituting the front edge or the trailing edge of the spot, the curve being contained in the plane comprising the first emitter and situated in front of the first emitter, the lens (L, L1, L ', La) is determined so that its section (Lc), by a plane (Vc) orthogonal to said control curve, is identical to that of a stigmatic reference lens between the point of intersection of the control curve with the orthogonal plane, and the infinite along the direction given by the intersection of the orthogonal plane and the plane of the curve, the material of the lens (L, L1, L ', La) of said module and said reference lens having the same refractive index, the first reflector and the lens being arranged to form the first cut-off beam after refraction by the lens of the rays deflected by the first reflector. Module according to one of the preceding claims, characterized in that the first reflector (R1, R'1) is determined in such a way that the images (11, 12) of the first emitter (1), which it supplies in the plane of this transmitter, meet the control curve (A, A '), while being entirely on the side of the light spot. A motor vehicle headlight lighting unit adapted to provide a light beam, said lighting unit comprising: - a transmitter (2) of plane light, to give the first beam; a lens (L, L1, L ', Lb) arranged in front of the emitters, a reflector (R2, R'2) for deflecting the rays emitted by the light emitter, characterized in that : - the reflective surface of the reflector (R2, R'2) is determined so that, in a reverse path of light, light rays (r3, r4) parallel to a given direction, after crossing and deflection by the lens (L, Lb) and reflection on the reflector (R2, R'2), meet the transmitter (2) at a given point of the transmitter, the lens (L, L1, L ', Lb) is determined so that its section (Lc), with a plane (Vc) orthogonal to a control curve (A, A'), is identical to that of a stigmatic reference lens between the point of intersection of the control curve with the orthogonal plane, and the infinite along the direction given by the intersection of the orthogonal plane and the plane of the curve, the material of said lens and said reference lens having the same refractive index, the control curve (A, A ') being located in front of the emitter, the reflector (R2, R'2) and lens (L, L1, L', Lb ) being arranged to form said light beam, after refraction by the lens rays deviated by the reflector. Lighting unit according to claim 3, characterized in that said given point of the transmitter (2) is a point of the front or rear edge of the transmitter. Lighting unit according to Claim 3, characterized in that the reflector (R2) is determined: - considering that the module comprises a blade (4) of zero thickness, having a front face (4s) merged with its rear face, consisting of a cylinder fraction generators orthogonal to the plane of the control curve (A), the front face admitting this control curve as a straight section; - considering that the front as an infinite vertical extent; such that, following a reverse path of light, light rays (r3, r4) parallel to an arbitrary direction, after crossing and deflection by the lens (L, Lb), after passing through the front rear face and then through the front face of the blade, and reflection on the reflector (R2), meet the transmitter (2) at a point near its center. Lighting unit (M5) according to one of claims 3 to 5, characterized in that the lighting unit is intended to be arranged in the motor vehicle headlamp, capable of providing a light beam, so that : the emitter (2) is arranged to emit a beam of light rays generally in a transverse direction, the reflector (R "2) is arranged to collect all of this beam of rays, said orthogonal plane (Vc) is orthogonal to a vertical plane. Lighting module according to claim 1 or 2, characterized in that it further comprises a lighting unit according to one of claims 3 to 5, the transmitter of said lighting unit corresponding to a second transmitter ( 2) of said lighting module, the reflector of said lighting unit corresponding to a second reflector (R2, R'2) of said lighting module, the first reflector (R1, R'1) and the lens (L, L1, L ') being arranged to form the first cut-off beam, and the second reflector (R2, R'2) and this lens (L, L1, L') being arranged to form a second light beam. . Module according to Claim 7, characterized in that the reflecting surface of the second reflector (R2, R'2) is determined in such a way that the second light beam is added to the first cut-off beam to thereby produce a road beam. Module according to any one of Claims 7 to 8, characterized in that either the second transmitter (2) transmits upwards and the first transmitter (1) transmits downwards, or the second transmitter (2) emits downwards. and the first transmitter (1) transmits upwardly. Module according to any one of claims 7 to 9, characterized in that the second emitter (2) is shifted transversely relative to the first emitter (1), so that the cut-off beam produced by the first reflector (R1 ) has an optical axis (Y1) different from the optical axis (Y2) of the beam produced by the second reflector (R2). Module according to claim 7, characterized in that the lighting unit is also according to claim 6. Module according to one of claims 1 to 2 or 7 to 10, characterized in that the light spot (S) is in front of the control curve (A), which control curve (A) is convex seen from the lens, or rectilinear. Module according to one of claims 1 to 2 or 7 to 12, characterized in that the first reflector (R1) is calculated so that for any point (p, pb) of the reflecting surface of the first reflector, a radius (r, rb) based on the control curve (A) and reflected at this point (p, pb) arrives after reflection on the front corner (1a, 1b) of the transmitter (1), located on the side opposite this point (p, pb), with respect to the vertical plane (Q1) passing through the optical axis. Module according to any one of claims 1 to 2 or 7 to 13, characterized in that the first transmitter (1) emits upwards, and creates with the first associated reflector (R1) a first cut-off beam whose illuminated area is located below its cutoff line, and in that the module comprises a blade (4) of transparent material having an upper planar face (4a) contained in the plane of the first emitter, and a front face (4s) consisting of in a fraction of a cylinder of generatrices orthogonal to the plane of the control curve (A), admitting this control curve as a cross section, so that the refracted part of the rays (5r) reaching the upper face enter the blade ( 4). Module according to Claim 7 taken in combination with one of Claims 12 to 14, characterized in that the second reflector (R2) is determined such that, in a reverse path of light, light rays (r3, r4 ) parallel to a given direction, after crossing and deflection by the lens (L), after crossing the front face (4s) and then the rear face (4e) of the blade, and reflection on the second reflector (R2), meet the second transmitter (2) at a point in its center, the front and rear faces being considered as infinite vertical extent. Module according to any one of claims 1 to 2 or 7 to 10, characterized in that the light spot (S ') in the plane of the first emitter is behind the control curve (A') which is concave from the lens, or rectilinear. Module according to any one of claims 1 to 2, 7 to 10 or according to claim 16, characterized in that the first reflector (R'1) comprises a first reflective surface portion calculated so that for any point ( m'4, m'6) of the first reflective surface portion of the reflector located outside the space between two planes (Q2 and Q3) passing through the rear corners (1c, 1d) of the transmitter (1 ) and parallel to a vertical plane (Q'1) passing through the optical axis, a radius (r'4, r'6) based on the control curve (A ') and reflected at this point (m') 4, m'6) arrives after reflection on the rear corner (1c, 1d) of the transmitter (1), located on the same side as the given point (m'4, m'6) with respect to the vertical plane ( Q'1) passing through the optical axis. Module according to claim 17, characterized in that the first reflector (R'1) comprises a second reflective surface portion calculated so that for any given point (m'5) of said second reflective surface portion located at inside the space between two planes (Q2 and Q3) passing through the rear corners (1c, 1d) of the transmitter (1) and parallel to a vertical plane (Q'1) passing through the optical axis , a ray (r'5) based on the control curve (A ') and reflected at this point (m'5) of said second reflective surface portion, arrives, after reflection, on the point (1e) of the rear edge of the transmitter (1) located in the plane which on the one hand contains this given point (m'5) of said second reflective surface portion, and on the other hand is parallel to the vertical plane (Q'1) passing through the optical axis. Motor vehicle headlamp, comprising at least one lighting module and / or a lighting unit according to one of the preceding claims.

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