EP1464890A1 - Vehicle headlamp capable of illuminating elevated signage - Google Patents

Abstract

The head light has a reflector that reflects a set of light signals from a light source. An output lens (405) includes an input surface, an output surface, and a focal point to produce a light beam. A cover plate is arranged between the reflector and the lens for clipping the light beam. The lens has convex ribs in a circumferential part of the output surface, to deflect a part of light in a pre-defined direction. An independent claim is also included for a vehicle equipped with a headlight.

Description

The present invention relates to a projector device equipping motor vehicles, and making it possible to obtain gantry complies with regulations.

In particular, it aims to propose a particular achievement of projectors which, while having a cover intended to prevent a light diffusion upward, allows to obtain a luminous intensity sufficient for a satisfactory visualization of certain placed elements in different areas above the beam cutoff line emitted by the projector.

• des feux de position, d'intensité et de portée faible ;
• des feux de croisement, ou codes, d'intensité plus forte et de portée sur la route avoisinant 70 mètres, qui sont utilisés essentiellement la nuit et dont la répartition du faisceau lumineux est telle qu'elle permet de ne pas éblouir le conducteur d'un véhicule croisé ;
• des feux de route longue portée, et des feux de complément de type longue portée, dont la zone de vision sur la route avoisine 200 mètres, et qui doivent être éteints lorsque l'on croise un autre véhicule afin de ne pas éblouir son conducteur ;
• des feux anti-brouillard.

The field of the invention is, in general, that of motor vehicle headlights. In this field, we know different types of projectors, among which we find essentially:

• position, intensity and low range lights;
• low beam, or codes, of greater intensity and range on the road of about 70 meters, which are used mainly at night and whose distribution of the light beam is such that it does not dazzle the driver of a crossover vehicle;
• long-range headlamps, and long-range supplement lights, whose vision zone on the road is approximately 200 meters, and which must be extinguished when crossing another vehicle so as not to dazzle its driver;
• fog lights.

The projector device according to the invention is more particularly intended to be used as a dipped beam, but the particularity of its structure, and in particular of its projection lens, could be reproduced on other types of projectors to meet different needs.

In the state of the art, it is known for the dipped beam basically two types of projector each having a structure separate.

The first type of projector consists essentially of a reflector associated with a light source. The reflector consists of a mirror having a set of streaks, or zones of various shapes, thus realizing a complex surface whose shape, which has previously made precise calculation object, makes it possible to reflect light signals emitted by the light source to produce a light beam essentially oriented horizontally and downward.

The second type of projector is shown in Figure 1. On this FIG. 1 is a sectional and side view of a dipped beam 100 known from the state of the art. Such a dipped beam comprises essentially a reflector 101, a light source 102, radiating a power in the form of light signals 103 emitted, disposed at near the top of the reflector 101, and an exit surface 104 of a light beam 106. The output surface 104 may be for example a plastic type ice cream; preferably, it does not have properties optical, that is to say that it does not deviate, or very little, the light rays who cross it.

Before reaching the exit surface 104, the light signals 103 have to cross, either directly or after reflection on the reflector 101, a lens 105. This lens is most often of the type convex and circular. It is called projection lens. She has a input face 110 and an output face 111. It images the light beam 106 whose orientation and scope depend in particular on the provision of the lens 105 within the projector device 100 and features lens optics 105. Preferably, a central portion of the source of light 102 is disposed in the focal zone of a first focus F1 of the reflector 101, and the focus of the projection lens 105 is in the focal zone of a second focus F2 of the reflector 101. Thus, a signal light 103 emitted by the central portion of the light source 102 will pass by the second focus F2 of the reflector 101 and exit the lens of projection 105 horizontally or approximately horizontally. AT the exception of light signals reflected on ends 107 of the reflector 101, the set of light signals 103 emitted by the party central light source 102 converge to the second focus F2.

Generally speaking, the expression "light signals" all the light rays emitted by the light source 102, and by light beam all of the light rays that are actually from a projector at the exit surface 104, or at the exit of the projection lens 105.

In this second type of projector, a cache 108 is interposed between the reflector 101 and the projection lens 105. The cover 108 is disposed in a plane parallel to the projection lens 105, approximately at the object focal plane of the lens, so that the image of the cache is emitted to infinity. Thanks to the presence of such a cache 108, the light beam 106 that is actually emitted by the device Projector 100 is not sent over a specific break line in the form of an upper portion 109 of the cover 108.

Figure 2 gives an example of the shape 200 of the light beam 106 projected on a screen. A cut-off line 201 marks the border between a low zone where the light intensity is sufficient to illuminate the road and satisfy the different regulations imposed, and a high zone where the light intensity is almost zero. The cutoff line 201 presents a change in height 203 at a central axis 202 of the beam. The shape 201 shown, with a higher light beam on the part right of the projection corresponds to that of a moving vehicle headlamp in a country where traffic is imposed on the right. In a country where circulation would be imposed on the left, one would obtain a form which, compared to a vertical axis 202, would be symmetrical to that shown.

The two types of headlamps described are now available on the market. The car manufacturers choose one or the other of these types of headlamps essentially according to aesthetic criteria, both projector types that do not look the same.

However, a problem arises with the second type of projector described. Indeed, if it is true that the light intensity must be low above the cut-off line 201, the different regulations nevertheless require that a minimum light intensity be emitted in certain directions above the cut-off line 201. In particular, different regulations impose a luminous intensity at certain points above the cut-off line, these points being called portal points because they correspond approximately to places in the vicinity of which there are sign boards of highway signs when these signs are at a given distance of visibility of the vehicle. For example, in a US regulation, there are three portal points that are located at 2u4l 4u8l and 4u8r respectively with respect to the optical axis of the lens and a line 1.5u1 r to 3R, the numbers corresponding to degrees, "u" corresponding to "up" (above), "l" corresponding to left (left), and "r" corresponding to right (right).

Various solutions have been proposed in the state of the art to help illuminate these portal points while maintaining the cache 108 in the projector device.

A first solution is to provide a hole in the cache 108. If this hole is in the right place, you get a lighted area approximately rectangular above the cut line, this zone containing the portal points. The regulatory requirements are thus satisfied, but the luminous intensity diffused in the rectangle is such that it is unpleasant - even embarrassing - for the driver.

A second known solution is to slightly roughen the face input of the lens 105. A part of the light signals is thus deflected of their initial trajectory and some are emitted towards the points of portico. But such a method has several disadvantages: on the one hand the diffuse frosted surface of light almost isotropically, a large amount of energy being wasted, including in areas of the beam where the intensity is already relatively weak; on the other hand, it is necessary to make post treatment of the lens after molding. In practice, we are therefore brought to perform a surfacing operation to obtain a face slightly frosted, this operation succeeding the molding operation.

The device according to the invention responds to the problems that come to be exposed. In general, the device according to the invention proposes a solution that allows to bring a controlled intensity light at the gantry points and in the vicinity of these points, while preserving the presence of a cache so as not to dazzle car drivers crossed and maintaining a good homogeneity of the light beam produced by the projector device to illuminate the road.

For this purpose, in the invention, it is proposed to modify the surface of the projection lens, and more particularly of certain areas of this exit area.

To do this, the invention proposes a vehicle projector device automobile, having at least one reflector, a source of light producing a set of light signals that can be reflected by the reflector, an exit lens, having an entrance surface, a exit surface and a focus, to produce a light beam, and a cover disposed between the reflector and the exit lens to form a line in the light beam produced, characterized in that the output lens comprises a set of arrangements made in minus a circumferential portion of the exit surface of the lens, this together being able to deviate in a certain direction a part of light signals encountering this arrangement.

According to a preferred embodiment, the deflection directions are directions above the cutoff line.

And preferably, these arrangements are able to divert a part light signals encountering this arrangement in one direction corresponding to a portal point.

According to a first variant embodiment, this part circumferential is arranged on the lower part of the lens.

In this case, preferably, it is substantially symmetrical by relative to a vertical plane of symmetry of the lens.

Advantageously, this circumferential portion extends over approximately 45 ° on each side of said plane of symmetry.

This first variant has the advantage of only modifying minimum the external appearance of the lens and therefore be very discreet on the plane visual.

According to a second variant embodiment, this part circumferential extends around the entire periphery of the lens.

This second preferred embodiment has the advantage of do not cause any angular positioning constraints of the lens. But he turns out that the realization of keying arrangement, the type notch on the lens fitting on a rib of its support, is an operation relatively delicate given the fragility of such lenses.

More specifically, preferably, this circumferential portion is consisting of a frustoconical surface of rectilinear generatrix inclined by a determined angle to get an upward deflection of the optical signals from the focus and crossing it at the low point of the lens.

Preferably, this deflection is between 2 and 10 °.

Advantageously, this circumferential portion is formed of convex ribs disposed on said frustoconical modified surface of the lens.

In this case, advantageously, said convex ribs are rotated on said frustoconical surface of a rib of dispersion of the light determined to obtain a lateral dispersion of the light at the low point of the lens.

A lens according to the invention can be designed by simulation and so its manufacturing process is stable. It can even be standardized and used for different projection devices.

It can also be manufactured in large series by a single molding operation. Its manufacture is therefore particularly economical.

The losses in range and flux in the optical beam are very low of the order of 2%.

Another object of the invention is a motor vehicle equipped with a projector device including at least one of the features that come to be mentioned.

La figure 1, déjà décrite, est une vue en coupe latérale d'un dispositif projecteur de l'état de la technique.

La figure 2, déjà décrite, est une représentation de la projection du faisceau lumineux émis par le dispositif projecteur de la figure 1.

La figure 3 est une vue de face d'une lentille conforme à l'invention.

Les figures 4A et 4B sont des vues schématiques d'une vue de face et en coupe d'une lentille et illustre une première étape de réalisation d'une lentille, selon un premier mode de réalisation.

Les figures 5A et 5B sont des vues schématiques d'une vue de face et en coupe d'une lentille et illustre une première étape de réalisation d'une lentille, selon un second mode de réalisation.

La figure 6 est une vue en coupe selon le plan A-A' de détail de la lentille conforme à l'invention, illustrant les deuxième et troisième étapes de réalisation de cette lentille.

La figure 7 est une vue en perspective d'une nervure, aménagement conforme à l'invention.

The invention is described below in more detail with the aid of figures representing only a preferred embodiment of the invention. In particular, the projector device according to the invention is illustrated in the case of use in a dipped beam, but this device is suitable for any projector device of a vehicle.

Figure 1, already described, is a side sectional view of a projector device of the state of the art.

FIG. 2, already described, is a representation of the projection of the light beam emitted by the headlight device of FIG.

Figure 3 is a front view of a lens according to the invention.

Figures 4A and 4B are schematic views of a front view and in section of a lens and illustrates a first step of producing a lens, according to a first embodiment.

Figures 5A and 5B are schematic views of a front view and in section of a lens and illustrates a first step of producing a lens, according to a second embodiment.

Figure 6 is a sectional view along the plane AA 'of detail of the lens according to the invention, illustrating the second and third steps of this lens.

Figure 7 is a perspective view of a rib, arrangement according to the invention.

In the different figures, the elements that are common to several figures have the same references.

FIG. 3 shows a projection lens 405 in front view, it is to say as we can see it when we are facing the projector. The lens can be circular or elliptical. A vertical axis 401 and a horizontal axis 402 intersect at the center of the circle forming the circumference of the lens.

The output lens 405 here comprises a set of arrangements made around its entire periphery of the exit surface of the lens, this together being able to deviate in a certain direction a part of light signals meeting him.

The deviation directions are directions above the cut and each corresponding to a portal point

This preferred embodiment has the advantage of not causing any angular positioning stress of the lens.

However, in the context of the invention, it is sufficient that this set of arrangements is arranged on the lower or upper part of the lens. Preferably, but this is absolutely not necessary, it is symmetrical with respect to a vertical plane of symmetry of the lens containing the vertical axis 401. This set is then on a beach angular angle at the center 2α, α being advantageously substantially equal at 45 °. This set can therefore also be substantially symmetrical only, or completely asymmetrical.

This circumferential portion 400 formed of this set of arrangements, consists of convex ribs 403 disposed on a frustoconical modified circumferential zone of the lens.

This conformation of this circumferential part 400 is going to be specified with reference to the following figures.

In these following figures 4 and 5 are shown schematically a first step of producing a lens according to the invention.

According to a first non-limiting embodiment represented on the 4A and 4B, the circumferential portion 400 'is disposed on the part of the lens 405 'and is preferably symmetrical with respect to a vertical plane of symmetry of the lens, whose trace in the plane of the figure is the vertical axis 401. This circumferential portion extends over an angle α, of preferably equal to about 45 °, on each side of this plane of symmetry.

The outer surface of the lens, as well as its focus F and its axis optical L, are shown in Figure 4B. This surface is schematized by the ellipse S1. The first step of producing a modified lens according to the invention consists in producing a frustoconical surface of rectilinear generator centered on the optical axis L of the schematized lens by the line S2. This surface S2 is defined to obtain a deviation towards the top of the optical signals coming from the focus F crossing it on the low point of The lens. Advantageously, in order to achieve the desired portal points by standards, this deviation is of angle β between 2 and 10 °, preferably between 5 and 9 °.

The advantage of only making this circumferential part in the the lower part of the lens lies in a concern for aesthetic discretion. This part will be less visible on the vehicle.

Moreover, it is also within the scope of the invention to realize this frustoconical part in the upper part of the lens. However, the The embodiment described here is preferred because it is more efficient in matter of light energy.

According to a second embodiment shown in FIGS. 5B, the circumferential portion 400 is disposed all around the periphery of the exit surface of the lens. The external surfaces of the lens S1 and S2 are defined identically to those in the previous figure.

This second embodiment has the advantage of not causing any angular positioning stress of the lens in the projector.

If, in the state resulting from this first stage of production, a part of the light rays crossing the lens is diverted to the level of this part 400 or 400 'to redirect the power thus diverted to the gantry points subject to regulation in terms of intensity luminous minimum to receive, it turns out that this diversion concentrates the light deflected in a central area near central axis 202 above 201. It is therefore not sufficient to fill the imperatives more demanding standards and does not realize all the points of standardized gantries. It is therefore necessary to disperse the beam of light thus obtained laterally to this central area.

To solve this problem, as shown in Figure 6, on any this frustoconical surface S2 are arranged convex ribs. Their not is defined so as to get an integer number of ribs on the around the lens and small enough not to interfere with the angular position of the lens. Preferably, this step corresponds to an angle in the center of 1 to 5 °, in view according to Figure 3. Their maximum thickness is calculated to divert only the necessary light, for example for a diameter lens equal to 70mm, a thickness of about 3mm.

Such a rib is shown in perspective in FIG. its plane of symmetry A-A '. For example, its height is of the order of 3 to 5mm, the radius of curvature of its line 12 representative of its convexity, or horizontal radius, of the order of 20mm and the radius of curvature of the line 11 of its side edge, or vertical radius, very large, this edge being almost straight.

More generally, the horizontal radius is determined in such a way known to those skilled in the art to achieve sufficient illumination laterally to the central zone already mentioned, more precisely according to certain standards of 8 ° on each side of the central axis of this zone. The vertical radius is determined meanwhile in a manner known to the man of craft to achieve the desired vertical distribution of light.

The set of convex ribs on the lens is made by rotation on the frustoconical surface S2 of a dispersion rib of the light as previously described with its lateral sides c1 and c2 corresponding to the surface S2 and determined to obtain the dispersion desired light at the low point of the lens.

Returning to FIG. 6, the ribs N, one of which is here in view section along its plane of symmetry A-A 'are then leveled in the extension of the profile of the surface S1, which is schematized on this figure by removing the hatched portion.

Advantageously, the sharp-edged slits existing between each rib will be filled with a rounding, to improve the result aesthetic.

Once determined, such a lens can be made by molding.

It should be noted that the only condition for ensuring photometry consistent on the gantry points is that the light reaches the low point of the lens. This is the case for most projector modules elliptical. Otherwise, it is sufficient to provide for an increase in Reflector height to reach the low point of the lens or to design the lens with a smaller diameter so that its low point corresponds to the reflection of the reflector, which leads to a lens of small size and reduced weight, which is particularly interesting.

Claims (12)

Motor vehicle headlamp device, comprising at least one reflector (101), a light source (102) producing a set of light signals (103) that can be reflected by the reflector (101), an output lens (401), comprising an input surface (110), an output surface (111) and a focus (F), for producing a light beam (106), and a cover (108) disposed between the reflector (101) and the output lens (401) for making a break (201) in the produced light beam (106), characterized in that the exit lens (401) comprises a set of arrangements made in at least a circumferential portion (400, 400 ') of the exit surface of the lens, this assembly being able to deflect in a given direction a portion of the light signals meeting this arrangement (400, 400 '). Projector device according to claim 1 characterized in that the deflection directions are directions located above the cutoff (201). Projector device according to one of the preceding claims characterized in that these arrangements (400, 400 ') are capable of deflecting a portion of the light signals meeting these arrangements in a direction corresponding to a portal point. Device according to one of the preceding claims, characterized in that this circumferential part (400 ') is arranged on the lower part of the lens. Device according to claim 4, characterized in that this circumferential portion (400 ') is substantially symmetrical with respect to a vertical plane of symmetry of the lens. Device according to claim 5, characterized in that this circumferential portion (400 ') extends about 45 ° on each side of said plane of symmetry. Device according to one of claims 1 to 3, characterized in that this circumferential portion (400) extends around the entire periphery of the lens (405). Device according to one of the preceding claims, characterized in that this circumferential portion (400) consists of a frustoconical surface (S2) of rectilinear generatrix inclined at a given angle to obtain a deflection (β) upwards of the signals. optics from the focus (F) and passing through the low point of the lens. Device according to claim 8, characterized in that said deflection (β) is between 2 and 10 °. Device according to claim 7 or 8, characterized in that said circumferential portion (400) is formed of convex ribs (403) disposed on said frustoconical modified surface (S2) of the lens. Device according to claim 10, characterized in that said convex ribs are made by rotation on said frustoconical surface (S2) of a determined light scattering rib to obtain a lateral dispersion of the light at the low point of the lens. Motor vehicle equipped with a headlamp device according to one of preceding claims.

Images