EP0465330B1 - Headlamp with several functions, especially for vehicles - Google Patents

Description

The present invention relates to a headlamp with several functions, in particular for a motor vehicle, adapted to improve the illumination of road signaling elements.

It relates more particularly to such a headlamp which includes a cut-off lighting function such as, for example, a so-called crossing function or a so-called anti-fog function.

In such cases the illumination range is reduced and does not make it possible to make the road signal elements visible from a very long distance.

A first object of the present invention is to create a projector with cut beams which overcomes this drawback.

It has already been proposed to equip motor vehicles with headlights capable of exclusively emitting ultraviolet radiation intended to make visible road signs comprising a coating which becomes fluorescent under the effect of ultraviolet radiation.

Such a projector, for example described in patent application DE-A-2,249,930, is intended to be added to the projectors, or to the pairs of projectors, normally fitted to a motor vehicle, in particular to perform the functions of so-called crossing and so-called road lighting.

Also known, from patent application WO-89/03778, a headlamp called a dipped headlamp, which emits a visible light beam below a cut-off line, and which emits an ultra-violet light beam above of this same cut.

A vehicle equipped with a pair of headlights conforming to this patent application must also comprise a pair of headlights adapted to emit a so-called road beam.

In the two aforementioned cases, it is necessary to provide a plurality of pairs of headlights to fulfill all the necessary functions of automotive lighting.

Patent application WO-A-90/08673 proposes a projector of the aforementioned type, capable moreover of emitting a complete light beam or a light beam with cut-off, a mobile blackout transparent to UV rays being susceptible in one of its positions, to intercept part of the light beam, in order to define the beam cut-off.

However, the position of the cut-off is determined by the position of the movable screen. As a result, any deviation in positioning, in particular caused by vibrations or shocks, causes a variation in the cut-off and therefore inadequate, even dangerous, lighting when the headlamp is dazzling.

The main object of the invention is to overcome this drawback.

• des moyens de lampe émettant à la fois un rayonnement visible et un rayonnement ultra-violet ;
• un réflecteur ;
• un occulteur monté déplaçable entre une position d'occultation, dans laquelle il intercepte tout rayonnement visible dirigé au-dessus de la coupure, et une position d'effacement dans laquelle il n'affecte sensiblement pas la transmission du rayonnement lumineux visible, ledit occulteur étant opaque au rayonnement lumineux visible et est, au moins partiellement, transparent au rayonnement ultra-violet ;
• une glace frontale de fermeture en un matériau transparent, au moins partiellement, au rayonnement ultra-violet,

est, selon l'invention, caractérisé en ce que ledit réflecteur comporte deux zones susceptibles d'engendrer respectivement deux faisceaux lumineux différents, en ce que lesdites zones sont disposées côte à côte et s'étendent chacune sur l'ensemble de la hauteur du réflecteur, chaque zone du réflecteur étant constituée par une partie d'une surface réfléchissante engendrant par elle-même le faisceau associé et en ce que ledit occulteur comprend au moins un écran qui, en position d'occultation, est situé latéralement par rapport auxdits moyens de lampe placés à l'intérieur dudit réflecteur :A headlamp with several functions, one of which corresponds to a cut-off beam, in particular for motor vehicles, adapted to improve the illumination of road signaling elements, comprising:

• lamp means emitting both visible and ultra-violet radiation;
• a reflector;
• a concealer mounted movable between a concealment position, in which it intercepts any visible radiation directed above the cut, and an erasure position in which it does not substantially affect the transmission of visible light radiation, said concealer being opaque to visible light radiation and is, at least partially, transparent to ultraviolet radiation;
• a closing front window made of a transparent material, at least partially, with ultraviolet radiation,

is, according to the invention, characterized in that said reflector comprises two zones capable of respectively generating two different light beams, in that said zones are arranged side by side and each extend over the entire height of the reflector , each zone of the reflector being constituted by a part of a reflecting surface generating by itself the associated beam and in that said concealer comprises at least one screen which, in the concealed position, is situated laterally with respect to said means of lamp placed inside said reflector:

Thus, thanks to the invention, a multifunctional projector is produced, which allows the emission of ultra-violet radiation above a cut-off line when a cut-off projection function is used.

Thus, with a single pair of projectors according to the invention, it is possible to precisely carry out all the necessary lighting functions, and to provide particularly effective illumination of the signaling elements.

Even better results are obtained by using all or part of the inventive arrangements below.

At least one of the two reflector zones is constituted by a surface capable of generating by itself a beam situated below a cut of generally horizontal orientation, and can be constituted by a surface capable of forming images of the light source whose highest points are located in the vicinity of the cut. The cut can be horizontal or delimited by a horizontal half-plane and by a half-plane inclined above the horizontal. In this case, the other zone of the reflector is preferably constituted by a surface capable of generating a concentrated beam in the vicinity of the optical axis.

The occultation means can comprise either a single screen for selectively obscuring the visible light rays emanating from the source in the direction of said other zone, or even two screens, at least one of which is transparent to ultraviolet radiation to selectively obscure the visible light rays from the source towards the two areas of the reflector, respectively. In this case, the screen capable of obscuring the rays emanating from the source in the direction of the first reflector zone can be crossed by at least one small orifice to allow a determined quantity of light to pass in the direction of said first zone.

Advantageously, the screen or each occultation screen comprises a plate articulated around a horizontal axis secured to a cover of direct light associated with the source, this plate being able to be brought into a position of occultation by a driving source such an electric motor associated with transmission means comprising for example gears and a link.

• la figure 1 est une vue de face simplifiée d'un projecteur conforme à l'invention ;
• la figure 2 est une vue en coupe horizontale du projecteur de la figure 1 ;
• la figure 3 est une vue en coupe verticale axiale du projecteur des figures 1 et 2 ;
• les figures 4a et 4b sont des vues de face schématiques du projecteur des figures 1 à 3, illustrant deux états possibles de celui-ci ;
• les figures 5a à 5d sont des vues de face schématiques illustrant quatre états possibles d'un projecteur selon une variante de réalisation de l'invention, et
• les figures 6a et 6b sont des vues de côté d'une réalisation concrète d'un dispositif d'occultation conforme à l'invention, présenté dans deux positions différentes.

Other aspects, objects and advantages of the present invention will appear better on reading the following detailed description of a preferred embodiment thereof, given by way of example and made with reference to the accompanying drawings, in which :

• Figure 1 is a simplified front view of a projector according to the invention;
• Figure 2 is a horizontal sectional view of the projector of Figure 1;
• Figure 3 is an axial vertical sectional view of the projector of Figures 1 and 2;
• Figures 4a and 4b are schematic front views of the projector of Figures 1 to 3, illustrating two possible states thereof;
• FIGS. 5a to 5d are schematic front views illustrating four possible states of a projector according to an alternative embodiment of the invention, and
• Figures 6a and 6b are side views of a concrete embodiment of a concealment device according to the invention, presented in two different positions.

Referring to Figures 1 to 3 and 4a, 4b, a projector according to the invention comprises lamp means 100 defining a light source, capable of emitting both radiation in the visible spectrum and in the UV spectrum, a reflector 200 and a closing front window 300.

The glass 300 is made of a transparent material, at least partially, with ultraviolet radiation.

It is also advantageously smooth.

In this example, the lamp means comprise a discharge lamp, capable of producing between two electrodes an elongated electric arc disposed essentially axially in the vicinity of the optical axis Ox, in a well-known way. In 102 and 104 are indicated respectively the base and the sealed bulb of the lamp. Its supply terminals are delimited by 108. Due to the importance of the luminous flux emitted by this type of lamp, a direct light cover 106 is also provided to avoid the glare of the drivers or pedestrians located in front of the vehicle. The cover 106 here has the shape of a cylinder of revolution closed at its front end and whose open rear end has a complex outline such that the rays directed towards optically inoperative parts of the reflector (cheeks, etc.) are intercepted by the cache.

The cover 106 is opaque to visible light radiation while being advantageously, but not necessarily, at least partially transparent to ultraviolet radiation.

The reflector 200 is here a reflector of low height and large width, truncated by two upper and lower cheeks 240, 250, essentially horizontal. In accordance with an essential aspect of the invention, the surface of the reflector 200 is divided into two distinct reflecting zones 210 and 220 capable of emitting two light beams of different types respectively, and this separation is carried out in the present example according to the plan vertical axial x0z of the projector. A separation according to two half-planes passing through the optical axis Ox, but of substantial inclination relative to the horizontal, as indicated by the dashed lines P and P ′, is also conceivable. It is thus easy to modify the respective areas of the reflective zones 210, 220, and consequently the intensities of the two beams formed.

For example, the left zone (in front view) 210 of the reflector may consist of a part of a reflective surface capable of generating by itself, that is to say without the intervention of a concealment mask or the like, the V-cut specific to the standard European passing beam. In practice, it may be half of an area among those described in French patents and patent applications Nos. 2.536.502, 2.599.121 and 2.609.148 in the name of the Applicant, whose respective contents are incorporated herein by reference, and to which reference will be made for further details.

In the present example, the right-hand zone 220 of the reflector is a part of a surface capable of generating a beam essentially complementary to the passing beam. It may, for example, be a portion of a paraboloid with respect to the focal point of which the arc is off-center, or even a half of the surface as described in French patent application No. 2,600,024, the content is also incorporated by reference and to which reference will be made for further details.

The projector also comprises, as shown diagrammatically in FIGS. 4a and 4b (and not illustrated in FIGS. 1 to 3 for the sake of clarity), a screening screen 420 which here has the shape of a half-cylinder of revolution of horizontal axis essentially coincident with the optical axis, which is articulated by an edge on an axis 440 parallel to the optical axis and located below the lamp, this axis being for example mounted on the direct light cover 106 .

The occultation screen 420 is opaque to visible light radiation, while being, at least in part, transparent to ultraviolet radiation.

Drive means (not illustrated), for example with an electric motor or an electromagnet, can be controlled from the passenger compartment of the vehicle to move the screen 420 between a first position or occluding position (FIG. 4a), in which it is placed against the cache 106 to intercept the radiation from the arc of the lamp towards the area 220 of the reflector, and a second position or erasing position (Figure 4b), in which it is released from the cover 106, the area 220 now being exposed to radiation. It is observed that, in this example, the zone 210 is always exposed to radiation.

It is clear that, in the situation in FIG. 4a, only the zone 210 is active, so that the beam formed in the visible spectrum is a European passing beam. It can be noted in this regard that the various surfaces mentioned above have the property of creating by themselves the whole of the beam even when only half of the surface is used.

The ultraviolet radiation also emitted is, at least in part, transmitted through the screen 420, so that the whole of the reflector participates in the reflection of the ultraviolet radiation.

In the situation in FIG. 4b, the whole of the reflector participates in the creation of the beam, so that the latter is constituted by the superposition of the driving beam generated by the area 210 and the complementary beam generated by the area 220, and thus constitutes a driving beam.

Referring now to FIGS. 5a to 5d, there are diagrammatically illustrated four possibilities of using a headlamp comprising a first reflecting zone 210 such as a surface forming by itself a passing beam and a second reflecting zone 220 in the form of a parabola focused in the vicinity of the arc of the lamp 100. Two screening screens 410, 420, for example articulated and mounted on the same axis 440 located below the lamp 100, are respectively associated with the areas 210 and 220 , to selectively expose them to light from the arc or, on the contrary, hide them. One of the two blackout screens 410, 420, and alternatively both, is opaque to visible light radiation, while being, at least in part, transparent to ultraviolet radiation. This projector is further characterized in that the screening screen 410 assigned to the area 210 of the reflector has one or more small orifices, as indicated in 412, to allow a predetermined quantity of the light emitted by the reflector to pass through. the arc.

In FIG. 5a, the two screens 410, 420 are in the occultation position, as illustrated, and only a small quantity of the visible light coming from the arc is authorized to exit towards the zone 210, which normally reflects it towards the 'before. This creates a so-called lantern or city lamp function, delivering a small amount of light in front of the vehicle intended for signaling the vehicle more than for lighting the road.

In this condition, ultraviolet radiation is advantageously emitted limited or not depending on whether one or the two screens 410, 420 are transparent to ultraviolet radiation.

In FIG. 5b, the concealment screen 410 is open. This situation is equivalent to that of FIG. 4a, and the headlamp emits a passing beam.

FIG. 5c illustrates the case where the blackout screen 410 is closed, while the blackout screen 420 is open. Only the region 220 of the reflector participates in the shape of the beam, so that the beam generated is an ordinary driving beam, concentrated on the optical axis.

Finally, FIG. 5d illustrates a last possibility offered by this reflector: by simultaneously opening the two screens 410, 420, the driving beam and the passing beam are superimposed, in this case obtaining an extremely powerful beam, offering visual comfort both in the distance and closer to the vehicle.

In both of these latter cases, ultraviolet radiation is emitted, at least in part, above the cut.

Thus, without any electrical switching of the lamp, but by appropriately controlling the means for moving the screening screens, this projector offers four light functions, all of excellent quality, with, in all cases, emission of a long-range ultraviolet radiation, that is to say not limited by any cut, making it possible to make visible road traffic signs, obstacles, mobiles or others, coated with fluorescent elements under the effect of ultraviolet radiation.

Figures 6a and 6b illustrate a practical embodiment of the concealment means used in the context of the present invention. An occulting screen 410 has been illustrated in these figures intended to selectively mask the left-hand part (in front view) 210 of the reflector from the radiation coming from the electric arc.

On a common support (not illustrated), for example integral with the reflector or the projector housing and coming from molding with it, is mounted a reversible electric motor 401 whose output shaft 401a carries a first gear 402. The latter meshes with a reduction gear formed by the gears 403, 404 and 405. The final gear 405 carries an eccentric pin 406 on which a first end of a link 407 is articulated.

The direct light cover 106, here of essentially square cross section, carries on a vertical extension 106a an axis 409 on which the screening screen 410 is articulated by means of a tab 410a. AT the free end of the tab 410a, that is to say opposite to the part providing the concealment with respect to the axis 409, is provided an axis 408 on which the other end of the link 407 is articulated.

It is understood that a rotation of the motor 401 causes, by means of the transmission constituted by the gears and the link, the passage of the screen 410 from the non-occultation or erasure position, illustrated on the Figure 6a, in the occultation position illustrated in Figure 6b, and vice versa. To ensure precise positioning of said screen in each of its two possible positions, it is possible, for example, to provide limit switches at an appropriate location of the transmission, or even a servo position control, these two solutions being well known from one skilled in the art.

It is observed that the blackout screen 410 has a contour such that, in the blackout position, it seals the entire space between the rear edge of the cover 106 and the base 102 of the lamp, to thus effectively preventing any visible light ray from reaching the reflecting area 210 of the reflector.

By way of example, it is indicated that the screening screen can be produced from a tinted glass or tempered glass support on which is deposited at least a thin layer of a material based on oxides of metals, such as titanium oxide (Ti02), silicon oxide (SiO) or, in general, a dielectric material, absorbing the rays of the visible spectrum and allowing, at least in part, the ultra-rays purple.

The screening screen can also be of the interference band type with a narrow band such as a known filter. under the name of Fabry-Pérot, or be of the diffraction type.

The present invention, by allowing the radiation of the code, road, or even lantern functions, and emission of ultra-violet radiation, makes it possible to achieve substantial savings compared to the systems of the prior art requiring a plurality of projectors.

And the fact that the ultraviolet radiation is partly reflected at least by an area of the reflector corresponding to a road lighting function, it makes it possible to considerably increase the efficiency and the range thereof.

Of course, the present invention is in no way limited to the embodiments described above and shown in the drawings. In particular, although the use of a discharge lamp is particularly advantageous for obvious reasons of efficiency, it is clear that the invention remains advantageous with conventional tungsten filament sources.

In this case, a lamp adapted to emit ultraviolet radiation is mounted near the tungsten filament lamp, the two lamps forming said lamp means.

Furthermore, any combination of beams other than that which has been indicated above can be envisaged. For example, one can provide a zone forming the European standard passing beam as described above, the other zone possibly being a parabola possibly off-center or a surface capable of forming a beam complementary to a passing beam. In the above headlamps, it is also possible to replace the zone forming the passing beam by a zone forming by itself an anti-fog beam, and responding for example to the surface as described in French patent application No. 2,536,503 in the name of the Applicant, the content of which is incorporated into the present description by reference.

Another possibility consists in using, for the concealable zone 220, a portion of paraboloid focused on the source and giving a so-called "spot" beam, extremely concentrated, and for the non-concealable zone 210 a surface such as that described in the patent application n ° 2,609,148, generating by itself a beam of road of great width.

Finally, the electromechanical occultation means, as described, can be the subject of numerous variants. For example, the drive can be performed using an electromagnet instead of the electric motor. It is also possible to use non-electromechanical occultation means, for example an electro-optical screen capable of assuming an opaque state and a transparent state, depending on the value of an electric voltage which is applied across its terminals.

Generally, a person skilled in the art will know how to conceal means having a switching speed fast enough to comply with the regulations, in particular as regards the crossing crossing en route and vice versa and "the lighthouse call ".

Claims (11)

1. A headlamp with a plurality of functions, one of which corresponds to a dipped beam, in particular for motor vehicles, being adapted to improve the illumination of road signs and including:

   - lamp means (100, 104) emitting visible radiation and ultraviolet radiation simultaneously;

   - a reflector (200);

   - an occulting means (410, 420) which is mounted for displacement between an occulting position, in which it intercepts all visible radiation directed above the cut-off line, and a retracted position in which it has substantially no effect on the transmission of visible light radiation, the said occulting means (410, 420) being opaque to visible light radiation and being, at least partially, transparent to ultraviolet radiation;

   - a front closure glass (300), of a material which is at least partially transparent to ultraviolet radiation,

   characterised in that the said reflector (200) has two zones (210, 220) which are adapted to generate, respectively, two different light beams, in that the said zones (210, 220) are disposed side by side, with each one extending over the entire height of the reflector, each zone of the reflector consisting of part of a reflective surface which by itself generates the associated beam, and in that the said occulting means comprises at least one screen (410, 420) which, in an occulting position, is situated laterally with respect to the said lamp means (100, 104) which are positioned inside the said reflector (200).
2. A headlamp according to Claim 1, characterised in that at least one of the two zones (210) of the reflector comprises a surface which is adapted so as, by itself, to generate a beam situated below a generally horizontally orientated cut-off line.
3. A headlamp according to Claim 2, characterised in that the said zone (210) comprises a surface which is adapted to form images of the light source defined by the said lamp means (100, 104), the highest points of which are situated in the vicinity of the cut-off line.
4. A headlamp according to Claim 3, characterised in that the cut-off line is a horizontal cut-off line.
5. A headlamp according to Claim 3, characterised in that the cut-off line is a normalised cut-off line delimited by a horizontal half plane and by a half plane which is inclined above the horizontal.
6. A headlamp according to one of Claims 2 to 5, characterised in that the other zone (220) of the reflector comprises a surface which is adapted to generate a beam concentrated in the vicinity of the optical axis.
7. A headlamp according to Claim 6, characterised in that the occulting means comprise a single screen (420) which is opaque to visible light radiation while also being at least partly transparent to ultraviolet radiation, so as selectively to occult visible light rays coming from the source towards the said other zone (220).
8. A headlamp according to Claim 6, characterized in that the occulting means comprise two screens (410, 420), at least one of which is opaque to visible light radiation while being at least partly transparent to ultraviolet radiation, so as selectively to occult visible light rays coming from the source towards the two zones (210, 220) of the reflector, respectively.
9. A headlamp according to Claim 8, characterized in that the screen (410) which is adapted to occult the rays coming from the source towards the first zone (210) of the reflector has at least one small through aperture (412) so as to allow a predetermined quantity of light to pass towards the said first zone.
10. A headlamp according to one of the preceding Claims, characterized in that the or each occulting screen comprises a plate (410, 420) which is pivoted about a horizontal axis (409) fixed to a direct light shield (106) associated with the source, the said plate being able to be put into an occulting position by a motor source (410) associated with transmission means (402-408).
11. A headlamp according to any one of the preceding Claims having a direct light shield (106), characterised in that the said direct light shield (106) is opaque to visible light radiation, while being at least partly transparent to ultraviolet radiation.

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