EP2390562B1 - Lighting module for headlights of an automobile - Google Patents

Description

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

The lighting modules of the state of the art generate a beam allowing the production of a light beam, allowing the illumination of the road, alone or in combination with the beam or beams of other modules. They generally include a set of optical elements associated to form the beam. Some of these beams are cut-off beams, in particular of the anti-fog or code type. Some modules, generating cutoff beams, use imaging lenses and a bender, i.e. a reflective plate or horizontal reflective cover, to create the cutoff.

Dual-function lighting modules are also known, in particular from FR 2 860 280 or after US 7,387,416 . The document EP 1 610 057 A1 also describes such a lighting module.

In some dual-function modules, the folding machine is used both for the upper cut-off of the code beam and for the lower cut-off of the additional beam, making it possible, in association with the code beam, to produce a high beam. The image of the leading edge forms a dark separation line between the beams given by the two transmitters to produce the driving beam. To avoid this dark band, it has been planned to make the common cut-off blurry by defocusing the folder or the lens, or by adding patterns to the latter. The merger of the two beams, taking place by means of blurred areas, also leaves a darker area between the two beams. The modifications tending to make the cut-off fuzzy reduce the value of the maximum intensity of the high beam. These drawbacks are present in the beams produced with the devices of the two patents mentioned above.

The object of the invention is to produce projectors that are simpler in design.

An object of the invention is a lighting module for a motor vehicle headlight, suitable for providing, in particular according to the command applied to it, a first cut-off beam, the lighting module is defined in claim 1.

Forward is understood to mean forward according to the direction of propagation of the light, from the light emitter towards the lens.

Such a module makes it possible to create a cut-off beam without the aid of a horizontal or vertical cover. 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 dual-function module, able to generate a cut-off beam, for example a code or a horizontal cut-off beam, and a second beam. with cut-off, which superimposed on the first produces a high beam. In fact, in this case, the absence of a cover, in particular horizontal, will make it easier to produce a dual-function lighting module giving a high beam not including a dark band between the superimposed beams. The presence of mechanisms necessary when the cache is mobile to pass from the route function to the code function is also avoided.

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-off and to bring the maximum intensity of the first beam closer to the cut-off of this first beam.

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

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

A variant of the invention relates to a lighting module comprising a lighting unit, as defined in claim 3.

The beam obtained by this embodiment also makes it possible to create a cut-off beam without the aid of a horizontal or vertical mask.

When this lighting unit is associated with a lighting module according to the invention, said given point of the emitter is a point on the front or rear edge of the emitter depending on whether the control curve respectively constitutes 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 thus also has 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 strip of zero thickness, having a front face coinciding with its rear face, consisting of a fraction of a cylinder 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 face as an infinite vertical extent; so that following a reverse path of light, light rays parallel to an arbitrary direction, for example chosen in a plane parallel to the plane of the emitter, after passing through and deflection by the lens, after passing through the rear face front then of the front rear face of the blade, and reflection on the reflector, meet the emitter at a point in the vicinity of its center;

this allows an alternative embodiment of the reflector of the lighting unit, in particular for producing a beam without cutoff; by neighborhood of the center of the transmitter is meant a point which is closer to its center than to its edges; preferably, the distance to the edge is 3 times greater than the center distance; more preferably, the distance to the edge is 10 times greater 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): $$\mathrm{d}1+\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="imgf0002.png,imgf0003.png"\; state="\{\{state\}\}">d</figure-callout>}2=\mathrm{K}$$
  
  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 characteristics stated in the previous paragraph, one or more of the following additional characteristics, any combination of these additional characteristics, to the extent where they are not mutually exclusive, constituting an advantageous example of embodiment of the invention:

• the lighting module further comprises a lighting unit according to the invention, the emitter of this lighting unit corresponding to a second emitter of the lighting module according to the invention, the reflector of the lighting unit lighting corresponding to a second reflector of the lighting module, the first reflector and the lens being arranged so as to form the first cut-off beam, and the second reflector and this lens being arranged so as to form the second light beam; the lens is therefore optically associated with the first reflector and with the second reflector; this makes it possible to reduce the bulk by having a single module to produce two light beams; it is thus possible to perform two lighting functions, for example by lighting the first beam alone, for a first function, and by superimposing the second beam on it, for a second function.
• the reflecting faces of the first reflector and of the second reflector face each other; such a module is more compact; preferably the first emitter emits to the first reflector and the second emitter emits to the second reflector; preferably, the lighting module comprises a common support for the first emitter and the second emitter, each of the emitters being located on either side of this support;

• the reflecting surface of the second reflector is determined such that the second light beam adds to the first cut-off beam to thereby produce a driving beam;
• the second beam has a low cutoff, so that the second beam can complement the first cutoff beam, the low cutoff of the second beam being adjacent or parallel to that of the first cutoff beam, preferably in this case slightly below the cutting of the first beam; as explained above, the production of a cut-off beam without the aid of a mask makes it possible to superimpose these beams while minimizing their overlap or by positioning them adjacent, without having a dark band.
• the second reflector is located either above the second emitter when the latter emits upwards, or below when it emits downwards
• the second transmitter transmits upwards and the first transmitter transmits downwards, or the second transmitter transmits downwards and the first transmitter transmits upwards; this makes it possible to improve the compactness of the module in width;
• the second emitter is offset transversely with respect 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; it is thus possible to bring the emitters closer to one another vertically, without the heat emitted by one of the emitters harming the other emitter; when the lighting module comprises a common support for the first emitter and the second emitter, each of the emitters being located on either side of this support, this also makes it possible to reduce the thickness of this support; furthermore, 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; it is for example possible to improve the efficiency of the beam resulting from the superposition of the first beam and of the second beam by spreading it out relative 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 viewed from the lens, or straight; this embodiment makes it possible to produce the module with a convex lens;
• the first reflector is calculated in such a way that for any point of the reflecting surface of the first reflector, a ray resting on the control curve and reflected at this point arrives after reflection on the front corner of the emitter, located in the side opposite to this point with respect to the vertical plane passing through the optical axis; in the present application by “radius based on the control curve” is meant a radius meeting this curve and contained in the plane perpendicular to the control curve at the point of intersection of the radius considered 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 front edge of the light emitter;
• for any given point on the reflecting surface of the first reflector (R1): $$\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="imgf0005.png,imgf0007.png"\; state="\{\{state\}\}">d</figure-callout>}1+\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="imgf0002.png,imgf0003.png"\; state="\{\{state\}\}">d</figure-callout>}2=\mathrm{K}$$
  
  or
  • d1 is the distance between on the one hand the corner of the emitter located on the side opposite 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 emitter emits upwards, and creates with the associated first reflector a first cut-off beam, the illuminated area of which is situated 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 fraction of a cylinder of generatrices orthogonal to the plane of the control curve, admitting this control curve as a straight section, so that the refracted part of the rays reaching the upper face enter the blade; this variant makes it possible to absorb 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 makes it possible to guide the parasitic rays at the bottom of the blade;
• the refractive index of the blade material is greater than √2; this improves the guiding of parasitic rays in the blade by total reflection;
• the upper front edge of the blade coincides with the control curve, and therefore passes through the focal point of the lens in a vertical section plane;
• the entry 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 such that, following a reverse path of the light, light rays parallel to a given direction, after passing through and deflection by the lens after passing through the front face and then the rear face of the blade, and reflection on the second reflector, meet the second emitter at a point of its center, the front and rear faces being considered to be of infinite vertical extent; in this case the cut in the second beam is not achieved 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, thus playing the role of a reflecting horizontal cover , that is to say, a folding machine;
• the light 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 emitter and parallel on a vertical plane passing through the optical axis, a ray resting on the control curve and reflected at this point arrives after reflection on the rear corner of the emitter, located on the same side as the given point with respect to the plane vertical passing through the optical axis; this embodiment is particularly suitable when the first transmitter transmits downwards; preferably, the first reflector comprises a second portion of reflecting surface calculated so that for any given point of said second portion of reflecting surface located inside the space between two planes passing through the rear corners of the emitter and parallel to a vertical plane passing through the optical axis, a ray resting on the control curve and reflected at this point of said second portion of the reflecting surface, arrives, after reflection, at 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 it emits downwards.

The subject of the invention is also a motor vehicle headlight, comprising at least one module according to the invention. The headlamp comprises for example a housing closed by a transparent closing glass, this module being inside the space closed by the housing and the glass.

This headlamp can produce a long-range lighting beam, by means of a lighting unit according to the invention, such as a high 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. A uniform dark appearance is thus obtained.

• 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 not claimed, the lighting module according to the invention can be associated with a lighting unit intended to be arranged in the headlight of a motor vehicle and able to provide a light beam, such that:

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

In the present application, the longitudinal direction corresponds to the direction going from the rear to the front of the vehicle, ie approximately the overall direction of emission of the lighting beam of the module or of the unit according to the invention. The vertical direction is perpendicular to the longitudinal direction and corresponds to the verticality when the unit or module is operating in a vehicle on a horizontal road. The transverse direction corresponds to a direction perpendicular to the longitudinal direction and to 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 headlight of a motor vehicle, suitable for providing a light beam, such that:

• the emitter is arranged to emit a beam of light rays generally in an approximately vertical direction,
• 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 along its greatest direction; it is thus possible to have a lighting unit arrangement with a limited overall height.

According to claim 3, it is possible to have a lighting module including a lighting unit. In this case, the lighting module and the lighting unit preferably share the same lens. This not only gains in homogeneous dark appearance, but also in compactness.

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

• 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 qui n'est pas celle revendiquée à partir de la revendication 3 mais qui pourrait être combiné à un module d'éclairage selon la revendication 1, avec une lentille de l'unité d'éclairage 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 set out above, of a certain number of other arrangements which will be dealt with more explicitly below with regard to exemplary embodiments described with reference to the accompanying drawings, but which are not in no way limiting. On these drawings:

• Fig. 1 is a schematic rear three-quarter perspective view from above of a lighting module according to the invention, in this example a dual-function module.
• Fig. 2 is a perspective diagram, with parts broken away, of the module in section through a vertical plane orthogonal to a point on 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 plan diagram showing the reflector calculation for the code transmitter.
• Fig. 5 is a diagram, in plan, illustrating images of the code transmitter given by the associated reflector.
• Fig. 6 is a plan diagram illustrating the calculation of the reflector associated with the second emitter for the high beam.
• Fig. 7 is an illustration of the light spot produced by the coded reflector in the horizontal plane of the emitter.
• Fig. 8 is a diagram of the isolux curves of the coded 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 transmitter for the high beam.
• Fig. 10 is a rear three-quarter perspective view from above of a module similar to that of Fig. 1 but additionally equipped with a blade to avoid stray light coming from the emitter.
• Fig. 11 is a vertical sectional diagram illustrating the module of Fig. 10 .
• Fig. 12 is a perspective view, similar to Fig. 1 , of a module according to the invention with a rectilinear control curve.
• Fig. 13 is also a perspective diagram of a rectilinear control curve module, further equipped with a blade to avoid stray light coming from the emitter.
• Fig. 14 is a top view of a module according to the invention with the beam of the second transmitter laterally offset with respect to the code beam.
• 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 code beam 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 of the front and 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 downwards while the complementary transmitter for the route transmits upwards.
• Fig. 20 is a horizontal 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 which is not that claimed from claim 3 but which could be combined with a lighting module according to claim 1, with a lens of the lighting unit extending vertically.
• Fig. 27 is a front view of the lighting unit according to Fig. 26 .
• Fig. 28 is a side view of the lighting unit according to Fig. 26 .
• Fig. 29 is a light beam produced by the lighting unit illustrated in Fig. 26 .

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

A first reflector R1 is associated with the emitter 1. In the example of Figs. 1-3 , the photoemissive emitter 1 of the first LED emits upwards and the first reflector R1 is arranged above the first LED. Depending on the variant of Fig. 18-19 which will be described later, the photoemissive emitter 1 of the first LED emits downwards and the reflector R'1 is arranged 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. The curve A constitutes the rear edge of the spot S, in particular when the reflector R1 is above the first emitter 1 as in the case of Fig. 1-3 . As a variant, this curve A can 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 emitter 1 and is located in front of this emitter.

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

As shown on Fig. 4 , the reflector R1 for the code is calculated by considering the reverse path of the light coming from a lens L so that a ray r resting on the control curve A and reflected at a point p of the first reflector R1 arrives on the front corner 1a of the emitter 1 , located on the side opposite to the point of the entry face of the lens L, from which the considered ray r originates, with respect to the vertical plane Q1 passing through the optical axis. By "ray based on the curve A" is meant a ray meeting the curve A and contained in the plane perpendicular to the curve A at the point of intersection of the ray considered and of the curve A. The optical axis is by example, as shown 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 ray 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 any given point (p, pb) of the reflecting surface of the first reflector (R1): $$\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="imgf0005.png,imgf0007.png"\; state="\{\{state\}\}">d</figure-callout>}1+\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="imgf0002.png,imgf0003.png"\; state="\{\{state\}\}">d</figure-callout>}2=\mathrm{K}$$

or

• d1 is the distance between on the one hand the corner (1a, 1b) of the emitter located on the side opposite the given point (p, pb), with respect to the vertical plane (Q1) passing through the optical axis and elsewhere 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 ( TO),
• 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 as the point pb to arrive at the front corner 1b located on the opposite side with respect to the plane Q1.

The L lens ( Fig. 1-3 ) is conjugate of the first reflector R1 and is determined such that its cut 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, according to the direction given by the intersection Δc of the plane Vc and 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 a person 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 draw D of any value,
• any entry face, for example plane,
• a thickness in the center of any value.

The draft D, which corresponds to the distance between the focus ac of a vertical section of the lens L and the entry face Le of this lens, is constant, and the section of the entry face Le by the plane Π1 is formed by a curve B parallel to the curve A at the distance D. This draw D, the section of the entry 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 ray e1 parallel to Δc. The ray r1 comes from the front edge of the emitter 1. The other light rays of the emitter 1 will come from a point located behind that which provides the ray r1 so that the reflected ray r2 will be above the ray r1 so as to meet the plane Π1 in front of the line A, in the spot S. This ray r2 will leave the lens L following 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 due to 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 assembly of the first emitter 1, the first reflector R1 and the lens L is a beam with horizontal cut-off, the cut-off line being determined by the curve A, which has no material thickness, and the beam is located below the cut-off line since the rays such as e2 are inclined downwards with respect to the horizontal plane Π1.

As shown on Fig. 5 , the images such as I1, I2 of LED 1 given by the different points of the first reflector R1 are located in front of curve A. One of the vertices of the rectangular image is in contact with curve A.

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

We then consider a second horizontal plane transmitter 2 having a transmission direction opposite to that of the first transmitter 1 and vertically offset with respect to this first transmitter 1 in its own transmission direction. This second emitter 2 can also be offset in top view relative to the first emitter 1 in order to facilitate the physical location of the sources, namely closer to or further from the lens L than the first emitter 1.

The second plane 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 driving beam.

In the case of Fig. 1-3 where the first LED emits upward, the second LED emits downward as shown in 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 which is added to the cut-off beam of the first reflector R1 to produce the driving 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 a reflector R2 located below or above the second emitter 2 is determined, depending on 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 emitter 2 at a point on its edge, front or rear, depending on the configuration of the system. We use the edge located on the same side as in the case of the first transmitter 1, namely in this example the edge forward in the direction of light propagation outside the module.

The second reflector R2 is determined as shown in Fig. 6 so that, following a reverse path of light, 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 from the second emitter 2. Still considering the reverse path of the light, the ray reflected last by the point m3 of the reflector R2 arrives at the corner 2a of the second emitter 2 situated on the side opposite the point m3 with respect to the vertical plane Q1 passing through the optical axis. For the ray 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 located at the other end of the front edge of the second emitter 2.

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

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

The parallel to the control curve A initially chosen, at a distance equal to the sum of the draw D of the stigmatic lens of construction and its thickness at the center, has no cusp or double point. This parallel corresponds to the section of the exit surface of the lens by the plane Π1 of the emitter 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, this must not be convex in the direction of the lens to obtain a flat cut-off;
• 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, the latter must not be concave in the direction.

• Fig. 7 est une illustration de la tache lumineuse S qui est produite dans le plan horizontal du premier émetteur 1. Cette tache lumineuse S pourrait être observée après retrait de la lentille L et mise en place d'un écran horizontal dans le plan du premier émetteur 1. La limite arrière de la tache S est formée par la courbe A, tandis que la limite avant B correspond à l'intersection de la face d'entrée de la lentille Le par le plan horizontal de la tache S.
• Fig. 8 illustre les courbes isolux du premier faisceau à coupure horizontale obtenu avec la première LED (premier émetteur 1), le réflecteur R1 et la lentille L. L'ensemble des lignes isolux du faisceau F1, c'est-à-dire sa zone éclairée, est situé sous la coupure horizontale, au-dessous de la ligne horizontale H de coupure.
• Fig. 9 illustre les courbes isolux du faisceau F2 obtenues avec la seconde LED 2, le réflecteur R2 et la lentille L, cet ensemble correspondant à l'unité d'éclairage précédemment décrite. Les courbes isolux du faisceau F2 sont situées au-dessus de la ligne H de coupure.

The properties stated 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 quantities: curve, draft, thickness at the center, and refractive index of the material of the stigmatic lens. 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 on the edge of the first emitter 1 and, for the second emitter 2, between the appropriate points on its edge and a surface d plane output wave, direction chosen beforehand.

• 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 removing the lens L and placing a horizontal screen in the plane of the first emitter 1. The rear limit 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 beam with horizontal cut-off 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 below the horizontal cutoff, below the horizontal cutoff line H.
• Fig. 9 illustrates the isolux curves of the beam F2 obtained with the second LED 2, the reflector R2 and the lens L, this assembly corresponding to the lighting unit described above. The isolux curves of the beam F2 are located above the cut-off line H.

Two possible improvements are now envisaged. In these two improvements, the second reflector R2, the emitter 2 and the lens L, form variants of the lighting unit 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 rays r3, r4 that is not horizontal and in particular inclined upwards is chosen if the beam created by the first emitter 1 is located above its cut-off line, or tilted down if this beam is located below its cut-off line. This arrangement makes it possible to guarantee, already for a low angle of inclination, of 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 the Fig. 1-3 and which corresponds to the case where the first emitter 1 radiates upwards and creates a beam located below its horizontal cut-off line ( Fig. 1-4 ).

Some LEDs may have weakly bright areas near the edges of their emitters 1. If an LED of this type is used to make the first emitter 1, noise appears above the cutoff, which, depending on the function performed ( and in particular the horizontal spread of the beam) can reduce the quality of the beam to a greater or lesser extent (these parasites potentially correspond to glare).

If the LED cannot be changed for a more suitable model, a blade made of transparent material 4 can be added to the system ( Fig.11 ) having an upper planar face 4a contained in the plane of the first emitter 1 and a front face consisting of a fraction of a cylinder of vertical generatrices admitting the control curve A for cross section. The rear face, located closer to the transmitter 1 than the front face, can 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 focal point of the lens L in a vertical section plane. The input face 4e of the blade 4 is convex towards the front and the output face 4s is parallel to the face 4e, the thickness of the blade being constant.

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

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

Such a device therefore ensures the absence of parasites above the cutoff. The fraction of energy lost by guidance is negligible. For example 0.58 Im for an LED at 600 Im - with 380 Im 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 into account the deviations (or, which is equivalent , the modification of optical path) introduced by this plate 4. In this calculation, the upper face of the guide is neglected and its front face is considered as an infinite vertical extent; in addition, we consider a single source point that must meet the construction rays, located in the center of the second emitter 2.

The second reflector R2 is determined such that, following a reverse path of the light, light rays r3, 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 then the front face of the plate, 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 blade thickness 4.

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

Variant

It is possible to obtain a variant with the two reflectors R1, R2 without a transparent blade, where the second reflector R2 is constructed by means of the calculations carried out for 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, un-cut 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. Although this variant results in a sending additional rays of light under the cut-off, it has the advantage of making it possible to obtain a much more intense beam than the image-aligned beam. In addition, it is possible to limit this quantity of rays sent under the cut-off by the second reflector R2 by shifting the second emitter 2 backwards.

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 emitter 2 and the lens L1, form a variant of the lighting unit according to the invention.

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

Referring to Fig. 14 , we can see, in plan, an M3 module with beam offset laterally. The cut-off beam produced by reflector R1 has an optical axis Y1 different from the optical axis Y2 of the beam produced by reflector R2 for the high beam. The lateral offset angle α of the high beam of axis Y2 with respect to the axis Y1 of the cut-off beam may be 14 °. The whole of the 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 laterally offset in the direction opposite 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 performance of the high 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 emitter 2 of Fig. 14 , beam which is located on either side of the horizontal cut-off line.

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

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

To improve the beam obtained by merging the two elementary beams, the additional beam F'2 "driving" should be placed with its maximum located 1% higher than the cut-off 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 associated first reflector R'1 is located below the LED 1. The LED 2 for the high beam emits upwards and the associated second 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.

The control curve A '( Fig. 20 ) is concave in the direction of the lens L '. The exit face L'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 rest on the curve A 'which corresponds to the focus of the stigmatic lens in a vertical section plane, similarly to what has been explained about Fig. 3 .

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

The rear edge of the second emitter 2 emits rays which, after reflection by the second reflector R'2, rest on the curve A 'or are situated 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 with respect to the horizontal.

In case the lens L 'is concave, as shown in Fig. 18 , with the transmitter code 1 emitting downwards, the first reflector R'1 is determined as illustrated on Fig. 21 so that the light rays r'4, r'6 considered following the reverse path of the light, converge towards the rear corners 1c, 1d of the rectangular plane 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 rear corners of transmitter 1.

When the intersection m'5 of a ray r'5, considered following the reverse path of the light, with the reflector R'1 is located between the planes Q2 and Q3 of the figure 22 , it reaches 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, we solve the equation describing the constancy of the optical path (according to Fermât's theorem) of the curve A 'at the corresponding source point of the emitter for three possible cases of hypothetical source points:

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

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

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 cut-off line, the first reflector R1 is determined so that it gives a spot of light located behind the control curve A, instead to be ahead in the example which has been described.

In the case of Figs. 18 and 19 , to obtain a cut-off beam situated above the cut-off, the first reflector R'1 is determined so that it gives a spot of light situated in front of the concave control curve A '.

Whatever solution is adopted, a cut-off beam is obtained by only controlling the ignition of the first emitter 1, and a high beam type beam by controlling the ignition of the two emitters 1 and 2. The two beams are merged. then in good conditions, without the presence of a dark band between them since there is no material edge of the folder. This fusion takes place without the need to control a mechanical movement of a folding machine.

The invention makes it possible to have a module with a toric lens rather than an elliptical one. 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 a sharp cut-off, and does not have a complex bender shape to compensate, always partially, for lens aberrations.

There is no risk of solar rays focusing on the surface of the reflector or the LEDs, causing 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, including when the size of the object tends towards 0. Good yields are obtained for the driving beam and for the coded beam compared to more conventional folding solutions. There are no difficult 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 present description, said module and said unit being two sets of distinct optical systems, with a separate lens. This use can be carried out in the same vehicle headlight, the lighting unit and the lighting module being placed in the headlight housing. The housing is preferably closed, preferably by a transparent closing 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 can be a lighting module according to the invention. In the example shown in figures 23 to 25 , this corresponds to a module such as the one illustrated in figure 1 , but without the reflector R2 or the emitter 2. The module Ma comprises a first reflector R1, deflecting the rays emitted by an LED 1 towards the lens La, to create a first beam in an overall direction X1.

The first reflector R1 and the lens La have a determined shape and are arranged like 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 can be a lighting unit according to the present description. In the example shown in figures 23 to 25 , this corresponds to a lighting unit such as the one illustrated in figure 1 , without a first reflector R1, nor a first emitter 1. The lighting unit Mb comprises a second reflector R2, deflecting the rays emitted by an LED 2 towards the lens Lb, to create a second beam in an overall direction X2.

The second reflector R2 and the lens Lb have a determined shape and are arranged like 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 can be a module such as that M4 illustrated in figure 18 , without the second reflector and without the second emitter. The lighting unit can then be a unit such as that R'2, 2, L ', illustrated in figure 18 , without the first reflector and without the first emitter.

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

In the example shown in figures 23 to 25 , in a nonlimiting manner, the first emitter 1 and the second emitter 2 are mounted on separate supports 3 ′ and 3 ". The first cut-off beam and the second beam can be beams such as previously described and be combined as previously described. The arrangement of the first reflector R1 relative to the second reflector R2 and / or the offset between the first emitter 1 and the second emitter 2 can be as described previously.

The invention also covers vehicle headlamps using lighting modules according to the invention but without a lighting unit as defined by claim 3, for example a module such as the lighting module Ma previously described and illustrated, without limitation, 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 produce an additional high beam, either in addition to or alternatively to the lighting of the first module which is still according to the invention.

The invention does not cover the lighting unit M5, as illustrated in Fig. 26 to Fig. 29 . This lighting unit can however be associated with a lighting module according to the present invention. For example, this unit is similar to the lighting module Mb 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 with respect to the mounting of the lighting unit Mb of the 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, suitable for providing a light beam, such 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 coordinate system has been placed to schematically represent the vertical "V", a transverse direction "T", and a longitudinal direction "L".

It is therefore observed that the planes along 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, along its greatest direction. . In the case of a toric lens, the directing curve is therefore vertical.

According to an alternative embodiment, this lighting unit M5 is produced so as to generate a beam with a cut-off, as described above for the formation of the complementary driving beam. This allows for a vertically cut beam when placed in the spotlight, since the lighting unit is rotated 90 ° compared to the units described in other modes.

According to another variant embodiment, this lighting unit M5 is produced so as to be able to generate a beam without cut-off, as described above, while placing the lens vertically. Surprisingly, the lens makes it possible to generate a high beam, as illustrated in 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, situated approximately entirely on one side of the vertical and longitudinal plane passing through the LED 2.

The advantage of this M 5 lighting unit is that it allows installation in a projector with a small transverse bulk. It also makes it possible to follow a curve in a vertical plane, and thus to produce high beams with a strong return to the top of the fender of the vehicle. It also allows for a different orientation for stylistic reasons.

Claims (15)

1. Lighting module for a motor vehicle headlight, specifically for providing a first beam with cut-off, said lighting module comprising:

   - a first, flat light emitter (1), giving the first beam;

   - a lens (L, L1, L', La) disposed in front of the emitter,

   - 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 rear 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 in such a way that its section (Lc), through a plane (Vc) orthogonal to said control curve (A) at any point, is identical to that of a stigmatic reference lens between the point of intersection of the control curve with the orthogonal plane, and the infinity in the direction given by the intersection of the orthogonal plane and of the plane of the curve, the material of the lens (L, L1, L', La) of said module and of said reference lens having the same refractive index, the first reflector and the lens being arranged so as to form the first beam with cut-off after refraction by the lens of the rays deflected by the first reflector, the cut-off line of the first beam with cut-off being determined by the control curve.
2. 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 (I1, 12) of the first emitter (1) that it provides in the plane of this emitter, encounter the control curve (A, A'), while being located entirely on the side of the light spot.
3. Module according to one of the preceding claims, further comprising a lighting unit for a motor vehicle headlight, specifically for providing a light beam, said lighting unit comprising:

   - a second flat light emitter (2), for giving the second beam;

   - a second reflector (R2, R'2) for deflecting the rays emitted by the second light emitter,

   characterized in that:

   - the reflecting surface of the reflector (R2, R'2) is determined in such a way that following a reverse path of the light, the light rays (r3, r4) parallel to a given direction, after having passed through and having been deflected by the lens (L, Lb) and reflected on the second reflector (R2, R'2), encounter the second emitter (2) at given points of the emitter,

   the second reflector (R2, R'2) and this lens (L, L1, L') being arranged so as to form a second light beam.
4. Module according to Claim 3, wherein the lighting unit is characterized in that said given points of the second emitter (2) are either points of the front edge or points of the rear edge of the emitter.
5. Module according to one of Claims 3 and 4, 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 beam with cut-off to thus produce a high beam.
6. Module according to Claim 5, characterized in that either the second emitter (2) emits upwards and the first emitter (1) emits downwards, or the second emitter (2) emits downwards and the first emitter (1) emits upwards.
7. Module according to either one of Claims 5 and 6, characterized in that the second emitter (2) is offset transversely with respect to the first emitter (1), so that the beam with cut-off produced by the first reflector (R1) has an optical axis (Y1) that is different from the optical axis (Y2) of the beam produced by the second reflector (R2).
8. Module according to one of Claims 1 and 2 or 3 and 4 or 5 to 7, characterized in that the light spot (S) is located in front of the control curve (A), which control curve (A) is convex when seen from the lens, or rectilinear.
9. Module according to one of Claims 1 and 2 or 3 and 4 or 5 to 8, characterized in that the first reflector (R1) is calculated in such a way that, for any point (p, pb) of the reflecting surface of the first reflector, a ray (r, rb) based on the control curve (A), and contained in the plane at right angles to the control curve at the point of intersection of the ray considered and of this curve, and reflected at this point (p, pb), arrives after reflection on the front corner (1a, 1b) of the emitter (1), situated on the side opposite this point (p, pb), with respect to the vertical plane (Q1) passing through the optical axis.
10. Module according to any one of Claims 1 and 2 or 3 and 4 or 5 to 9, characterized in that the first emitter (1) emits upwards, and creates, with the first associated reflector (R1), a first beam with cut-off of which the illuminated zone is situated below its line of cut-off, and in that the module includes a plate (4) made of transparent material having a flat top face (4a) contained in the plane of the first emitter, and a front face (4s) consisting of a fraction of cylinder of generatrices orthogonal to the plane of the control curve (A), admitting this control curve as cross-section, so that the refracted part of the rays (5r), coming from stray rays emitted on the side of the emitter, and reaching the top face, enter into the plate (4).
11. Module according to one of Claims 3 and 4 taken in combination with one of Claims 8 to 10, characterized in that the second reflector (R2) is determined in such a way that, following a reverse path of the light, the light rays (r3, r4) parallel to a given direction, after having passed through and been deflected by the lens (L), after having passed through the front face (4s) then the rear face (4e) of the plate, and having been reflected on the second reflector (R2), encounter the second emitter (2) at a point of its centre, the front and rear faces being considered to be of infinite vertical extent.
12. Module according to any one of Claims 1 and 2 or 3 and 4 or 5 to 7, characterized in that the light spot (S') in the plane of the first emitter is located behind the control curve (A') which is concave when seen from the lens, or rectilinear.
13. Module according to any one of Claims 1 and 2, 3 and 4 or 5 to 7 or according to Claim 12, characterized in that the first reflector (R'1) comprises a first portion of reflecting surface calculated in such a way that, for any point (m'4, m'6) of the first portion of reflecting surface of the reflector situated outside of the space included between two planes (Q2 and Q3) passing through the rear corners (1c, 1d) of the emitter (1) and parallel to a vertical plane (Q'1) passing through the optical axis, a ray (r'4, r'6) based on the control curve (A'), and contained in the plane at right angles to the control curve at the point of intersection of the ray considered and of this curve, and reflected at this point (m'4, m'6) arrives after reflection on the rear corner (1c, 1d) of the emitter (1), situated 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.
14. Module according to Claim 13, characterized in that the first reflector (R'1) comprises a second portion of reflecting surface calculated in such a way that, for any given point (m'5) of said second portion of reflecting surface situated inside the space included between two planes (Q2 and Q3) passing through the rear corners (1c, 1d) of the emitter (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 contained in the plane at right angles to the control curve at the point of intersection of the ray considered and of this curve, and reflected at this point (m'5) of said second portion of reflecting surface, arrives, after reflection, on this point (1e) of the rear edge of the emitter (1) situated in the plane which, on the one hand, contains this given point (m'5) of said second portion of reflecting surface, and, on the other hand, is parallel to the vertical plane (Q'1) passing through the optical axis.
15. Motor vehicle headlight, comprising at least one lighting module according to one of the preceding claims.

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