EP1739345A1 - Optical module for automotive vehicle - Google Patents

Abstract

The module has a light source (S) placed at an inner focus (Fi) of an ellipsoidal main reflector (1). A convex lens (2) has a primary focal point located near another focus (Fe) of the reflector. A quadric additional reflector (4) with curved surface has a focus merged with the inner focus and parameters different from that of the reflector (1). The reflector (4) is inserted and fixed in the reflector (1) by a leg assembly. The reflector (4) has reduced thickness in its rear zone such that its inner surface is connected tangential to an inner surface of the reflector (1). An independent claim is also included for a motor vehicle lighting device.

Description

• un réflecteur principal, par exemple sous une forme sensiblement ellipsoïdale,
• une source lumineuse placée à un premier foyer interne du réflecteur,
• et un moyen optique convergent dont le foyer est situé au voisinage du second foyer du réflecteur.

The invention relates to a lighting device of the type projector for a motor vehicle, of the kind that include:

• a main reflector, for example in a substantially ellipsoidal form,
• a light source placed at a first internal focus of the reflector,
• and a convergent optical means whose focus is in the vicinity of the second focus of the reflector.

The invention relates more particularly, but not exclusively, to an optical module, in particular of code, fog or highway code called "motorway", intended to produce at least one light beam with a cut in the upper region of the beam, this optical module having a cover located in the vicinity of the second focus of the reflector, cache whose upper edge determines the cut.

A projector optical module, for example road or code projector, must provide a light beam whose photometry meets the requirements imposed by the regulations in force.

However, a light beam while meeting the regulatory requirements may have different photometries. For example, the isolux curves of the beam on a screen located at a distance, generally 25 m, from the headlamp and orthogonal to the optical axis of the headlamp, may be more or less narrowed in the vertical direction or more or less spread in the horizontal direction. . This results in different illumination of the road on which the vehicle is traveling and aisles.

Some car manufacturers or some users can thus find that a light beam obtained with a standard optical module does not suit them because, for example, too wide or too high height.

Although it is possible to make as many optical module with specific ellipsoid-type reflectors adapted to the multiple definitions of the beam desired by the various users or manufacturers, such a solution is not economically viable because entailing prohibitive costs.

The object of the invention is, above all, to provide a projector optical module which, while remaining at an acceptable cost price, makes it possible to produce a light beam better adapted to the requirements of the various manufacturers or users.

According to the invention, a projector optical module of the kind defined above is such that an additional reflector with a curved surface having a substantially coincidental focus with the internal focus of the main reflector, but with different parameters from those of the main reflector, is inserted into this reflector, preferably without substantially increasing the dimensions, which allows, in particular, to change the characteristics of the light beam according to the requirements.

Advantageously, the term "inserted" requires that the additional reflector is fitted into the main reflector, to a given depth: a portion of the main reflector is thus covered, hidden by the additional reflector. These overlapping reflector portions may be in mechanical contact continuously or not, but even in the latter case, they are very close to each other. The total depth of the main reflector + additional reflector assembly is thus substantially identical to that of the main reflector alone. The surface of the additional reflector that overlaps that of the main reflector "replaces" it optically.

The main reflector is preferably of a shape close to an ellipsoid. This term includes a reflector surface which is substantially in accordance with an ellipsoid. More specifically, it is a reflector defined so that everything happens as if its first focus were fixed and its second focus was variable, this second focus being all the more distant from the first one that we consider a point of the reflector remote from the bottom of said reflector.

Preferably, the additional reflector is of quadric type. It can be close to an elliptical, a parabolic or a conical shape. It may be a reflective surface constructed from a generator close to an ellipse and whose ends are close to a parabola.

It can be located in the front part of the main reflector and form a crown or ring, or in the rear part.

Thus, according to the invention, while retaining a standard optical module, it is possible to obtain in a simple and economical manner a large variety of light beams, adapted to the requirements, without significantly modifying the overall dimensions of the optical module.

The rear edge of an additional ring-shaped reflector may be located in a plane, in particular orthogonal to the optical axis of the main reflector. Alternatively, the rear edge of the additional reflector may form a left curve.

The additional reflector located in the front part can be provided to change the width of the light beam.

It is also possible to arrange the additional reflector in the rear part of the main reflector to influence the depth of the beam.

The optical module may be provided to produce a light beam with a cutoff in the upper region of the beam and then comprise a cover located in the vicinity of the second focus of the main reflector, the upper edge determining the breaking of the beam.

The optical module can be of the bi-function type, for example road / code, in which case the cache provided for the light beam with cutoff is retractable for the road function. It can also be multi-function, with a cache that can adopt at least three different positions for the module to emit at least three different types of beams.

The additional reflector may be made of molded plastic whose inner surface is reflective, for example by aluminization, or be made of cast aluminum.

The thickness of the additional reflector is preferably reduced, for example from 5 to 7 tenths of a millimeter. To limit the break at the connection of the rear part of an additional reflector located forward (or of the front part of an additional reflector located in the bottom of the main reflector) with the inner surface of the main reflector, provision is made advantageously a gradual decrease in the thickness of the additional reflector in the connection area so that the reflective inner surface of the additional reflector is connected almost tangentially to the inner surface of the main reflector.

The attachment of the additional reflector in the reflector can be effected by means of a base generally intended for fixing and centering a lens support. In particular, the main reflector may comprise at the front a flange comprising a plurality of pins or centering studs projecting forwards, a lens is mounted in the front face of a housing whose rear face is open and limited in parts. high and low by flanges having orifices arranged to be traversed by the pins of the main reflector, and the additional reflector is secured at its front end, a flange which has orifices arranged in the same manner as those of the rim of the main reflector, so that the pins can engage in these holes and thus ensure the centering and attachment of the additional reflector.

• Fig. 1 est une coupe verticale schématique d'un module optique selon l'invention.
• Fig. 2 est une vue schématique en perspective d'un réflecteur additionnel dont le bord arrière est formé par une courbe gauche.
• Fig. 3 est une vue schématique en perspective éclatée avec partie arrachée d'un projecteur selon l'invention.
• Fig. 4 est une vue en perspective simplifiée du module optique.
• Fig. 5 est une représentation simplifiée du réseau de courbes isolux obtenu avec un module optique route standard à réflecteur principal de forme proche d'un ellipsoïde.
• Fig. 6 montre, semblablement à Fig. 5, le réseau de courbes isolux obtenu avec un projecteur selon l'invention issu du module optique standard de Figure. 5.
• Fig. 7 illustre le réseau d'isolux ajouté par le réflecteur additionnel, et
• Fig. 8 illustre le réseau d'isolux fourni par la partie de fond du module optique selon l'invention.

The invention consists, apart from the arrangements set out above, in a certain number of other arrangements which will be more explicitly discussed below with regard to exemplary embodiments described with reference to the accompanying drawings, but which are in no way limiting. On these drawings:

• Fig. 1 is a schematic vertical section of an optical module according to the invention.
• Fig. 2 is a schematic perspective view of an additional reflector whose rear edge is formed by a left curve.
• Fig. 3 is a schematic perspective exploded view with part torn off a projector according to the invention.
• Fig. 4 is a simplified perspective view of the optical module.
• Fig. 5 is a simplified representation of the network of isolux curves obtained with a standard optical road module with main reflector of shape close to an ellipsoid.
• Fig. 6 shows, similarly to FIG. 5, the network of isolux curves obtained with a projector according to the invention from the standard optical module of Figure. 5.
• Fig. 7 illustrates the network of isolux added by the additional reflector, and
• Fig. 8 illustrates the isolux network provided by the bottom portion of the optical module according to the invention.

Referring to Fig. 1 of the drawings, it is possible to see, schematically represented, a light projector optical module P for a motor vehicle, according to the invention, which comprises a reflector 1 of shape type close to an ellipsoid (hereinafter referred to as ellipsoid by conciseness concerns), a light source S placed at a first focus, or internal focal point Fi of the reflector, and a convergent optical means advantageously formed by a convergent lens 2 whose object focus is located in the vicinity of the second focus Fe or external focus of reflector 1, or is confused with Fe.

The light source S may be of different types, for example halogen lamp, or xenon discharge lamp, or one or more light-emitting diodes.

The optical module P may be a code optical module giving a cut-off beam above a predetermined line, in which case the optical module comprises a cover 3 situated in the vicinity of the focus of the lens 2 and the second focus Fe with an edge greater than substantially at the optical axis XX of the reflector 1. The upper edge of the cover 3-determines the cutting of the beam. The optical module P may also be an optical optical module in which case the cover 3 is removed or the optical module P may be of the bi function type with a retractable cover 3, for example by pivoting about a transverse horizontal axis, for move from function code to the route function or vice versa.

The axial dimension L of the optical module 1 corresponds to the distance between the vertical planes tangent to the rear end of the optical module1 and to the open front face of this optical module.

According to the invention, an additional reflector 4 with a curved surface, having a focal point substantially coinciding with the internal focal point Fi of the reflector 1, is inserted into the ellipsoid reflector 1 and is fixed thereto, without substantially increasing its dimensions, in particular the depth L. The additional reflector 4 has different parameters from those of the ellipsoid reflector 1 in order to modify the characteristics of the light beam of the optical module.

By way of example, reference is made to FIG. 5 which illustrates an isolux network obtained with a standard road projector comprising only the ellipsoid reflector 1. It appears that the isolux curves in the extreme lateral zones Zd and Zg are relatively pinched because their dimension h in the vertical direction is substantially reduced.

Some manufacturers or users wish that the light beam obtained is less pinched, that is to say that the height of Zd and Zg zones on the photometry screen is greater.

In the case of this example, the additional reflector 4 of the invention is calculated to modify accordingly the network of isolux curves. Fig. 6 illustrates the network obtained with such additional reflector 4; the light beam is thickened in the zones Zd, Zg which have a height h1 clearly greater than h of FIG. 5.

According to the example of FIG. 1, the additional reflector 4 is of elliptical or parabolic type. It is located in the front part of the ellipsoid reflector 1 and forms a ring corresponding to a section of ellipsoid or paraboloid. The terms "front" and "rear" used in the present description are to be considered according to the direction of propagation of the light.

The light source S can be oriented in the direction of the optical axis X-X or transversely to this axis.

In Fig. 1, there is shown several light rays from the source S. The rays i1, i2 which fall on the reflector 1 are reflected so as to pass through the external focus Fe or in the vicinity and out of the lens 2 substantially parallel to the optical axis. By against light rays such as i3 from the source S and falling on the additional reflector 4 out of the lens 2 being inclined downwards. The second focus of the reflector 4 is in front of the external focus Fe of the ellipsoid reflector 1.

It is thus possible, according to the invention, to modify the light beam of the optical module P practically at will by inserting the additional reflector 4 calculated for this purpose, without having to modify the standard main reflector 1.

The front edge 4a of the additional reflector 4 is located in the plane of the opening of the reflector 1, or substantially in this plane. The trailing edge 4b may be located in a plane, in particular orthogonal to the X-X axis as illustrated in FIG. 1, or can be formed by a left curve 4bb (FIG. 2) determined according to the modifications to be made to the isolux network. In the example of FIG. 2 the curve 4bb substantially corresponds to the intersection of the additional reflector 4 with a cylinder of revolution of horizontal axis orthogonal to the optical axis X-X. The dimension of the additional reflector 4 of FIG. 2, in a direction parallel to the optical axis is minimal in the horizontal plane passing through the optical axis and maximum in the vertical plane passing through this optical axis.

The attachment of the additional reflector 4 in the reflector 1 can be effected as illustrated in FIG. 3, using a base generally provided for fixing and centering the support of the lens 2.

More specifically, the reflector 1 comprises at the front a flange B molded in one piece with the reflector, for example with a rectangular contour, which surrounds the opening of the reflector 1, in a plane orthogonal to the optical axis. This flange B comprises three pawns or pins D projecting forward, for example a pin in the vicinity of each upper lateral end and a pawn in the lower central part. The lens 2 is mounted in the front face of a housing 5 whose rear face is open and limited in upper and lower parts by vertical flanges 5a, 5b having orifices E, respectively two orifices E on the upper flange 5a and a central hole E in the lower flange 5b. These orifices E are arranged so as to be traversed by the pins D to ensure the centering and the fixing of the housing 5 and the lens 2. For fixing, it is possible to provide threaded ends on the pins D with which they cooperate. lock nuts.

The additional reflector 4 may be secured, at its front end, with a flange G located in a plane orthogonal to the optical axis, molded in one piece with the reflector 4 and whose outer contour corresponds to that of the flange B This rim G has three orifices E1 arranged in the same manner as the orifices E so that the pins D can engage in the orifices E1 and thus ensure the centering and the fixing of the additional reflector 4 inserted into the reflector 1. The flange G is sandwiched between flanges B and 5a, 5b.

The additional reflector 4 may be made of molded plastic whose inner surface is reflectorized, for example by aluminization, or be made of cast aluminum. The thickness of the additional reflector 4 is reduced, for example from 5 to 7 tenths of a millimeter. To limit the break at the connection of the rear part 4b (Fig.1) of the reflector 4 with the inner surface of the ellipsoid reflector 1, a progressive decrease in the thickness of the reflector 4 in the rear area 4b is provided so that the surface reflective internal reflector 4 is connected almost tangentially to the inner surface of the reflector 1. It can thus ensure a recovery of the isolux curves of the bottom portion of the reflector 1 and the additional reflector 4.

The optical module according to the invention constitutes a standard elliptical module, in particular code, with scalable performance of constant dimensions. The evolution of the performances is obtained by a simple insertion of the additional reflector 4 in a reflector 1 which is not modified elsewhere.

The positioning of the flexible part, constituted by the additional reflector 4, with respect to the original surface of the reflector 1 is not detrimental, since the recovered light contributes mainly to the width of the beam, when the two surfaces make up the whole of the code module.

The projector according to the invention incorporating one or more modules according to the invention, and the modules themselves, are thus easily adjustable without requiring significant investments, and provides a wide photometric choice while maintaining a standard elliptical portion.

The bottom of the reflector contributes to the range of the light beam while the edge constituted by the additional reflector 4 contributes mainly to the width of the light beam.

The additional reflector 4 may be substantially conical. This additional flexible reflector removes a quantity of light from the standard part to place it judiciously in the photometry of the isolux.

The example described with reference to FIG. 1 corresponds to a reflector base constituted by the standard reflector 1 and a flexible edge constituted by the ring 4. This arrangement contributes to thicken the light beam in width.

It should be noted that one can reverse the modularity of the assembly, that is to say that the additional reflector would constitute the adjustable bottom, while the edge of the main reflector 1 would be used. The pinched edges of the zones Zd and Zg of FIG. 5 would then be preserved, but the range of the light beam in the central part would be increased. This modularity remains valid for a elliptical projector bi function, or for a road projector.

To limit the rupture at the connection of the front part of the additional reflector, located in the bottom of the ellipsoid reflector, with the inner surface of the ellipsoid reflector, it is advantageous to progressively reduce the thickness of the additional reflector in the connection zone so that that the reflective inner surface of the additional reflector connects almost tangentially to the inner surface of the main reflector.

An elliptical module or projector of standard appearance, with an inner modular surface 4 according to the invention, makes it possible to obtain a different beam according to the definition of this surface 4 and the desired shape for the light beam, without requiring too much investment. important.

The changes in the light beam may consist of thickening, thinning, or widening, or shrinking, or making this bundle deeper.

Fig. 4 is a perspective view of the elements of the projector according to the invention, without its housing. The cache was not represented; a cover for a European code beam would have an inverted V-shaped top edge with a horizontal side and another side inclined downwards at 15 ° on the horizontal. The image of this edge provided by the lens determines the cutoff of the code beam.

Fig. 7 represents the network of isolux produced by the only additional reflector 4, while FIG. 8 represents the network of isolux produced by the single bottom portion of the main reflector ellipsoid 1.

Claims (13)

Optical module for a motor vehicle lighting device, comprising: a main reflector, (1), a light source (S) placed at a first internal focus (Fi) of the main reflector (1), - and convergent optical means (2) whose focus is located in the vicinity of the second focus (Fe) of the reflector, characterized in that an additional reflector (4) with a curved surface having a focus substantially coincident with the internal focus (Fi) of the main reflector (1), but with different parameters from those of the main reflector, is inserted in this main reflector (1), without substantially increasing the dimensions, in particular to change the characteristics of the light beam according to the requirements. Module according to Claim 1, characterized in that the additional reflector (4) is of the quadric type. Module according to one of the preceding claims, characterized in that the main reflector (1) has a shape close to an ellipsoid. Module according to one of the preceding claims, characterized in that the additional reflector (4) is located in the front part of the main reflector (1) and forms a ring or a ring. Module according to Claim 4, characterized in that the rear edge (4b) of the additional ring-shaped reflector (4) is situated in a plane, in particular orthogonal to the optical axis (XX) of the main reflector (1). . Module according to claim 4, characterized in that the rear edge (4bb) of the additional reflector (4) forms a left curve. Modules according to claim 1 or 2, characterized in that the additional reflector is located in the rear part of the main reflector (1). Module according to one of the preceding claims, characterized in that , in order to limit the break at the connection of the rear part (4b) of a reflector an additional reflector (4) located forwardly, or of the front part of an additional reflector located in the bottom of the main reflector (1), with the inner surface of the main reflector, the additional reflector has a progressive decrease in the thickness in the connection area so that the reflective inner surface of the additional reflector connects almost tangentially to the inner surface of the main reflector. Module according to one of the preceding claims, characterized in that the additional reflector (4) is made of molded plastic, the inner surface of which is reflectorized, or is made of cast aluminum. Module according to claim 3, characterized in that the fixing of the additional reflector (4) in the main reflector (1) is carried out using a base (D) intended for fixing and centering a support ( 5) lens (2). Module according to the preceding claim, characterized in that the main reflector (1) has at the front a flange (B) with a plurality of centering pins (D) projecting forwards, a lens (2) is mounted in the front face of a housing (5) whose rear face is open and limited in upper and lower parts by flanges (5a, 5b) having orifices (E) arranged to be traversed by the pins (D) of the reflector main, and the additional reflector (4) is secured, at its front end, a flange (G), having orifices (E1) arranged in the same manner as those (E) of the rim of the main reflector, so that the pins (D) can engage in these orifices (E1) and thus ensure the centering and fixing of the additional reflector (4). Module according to one of the preceding claims, characterized in that it is bi function, including road / code, the cache provided for the light beam with cut-off being retractable for the road function. Motor vehicle lighting device comprising an optical module according to one of the preceding claims.

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