EP2604915B1 - Lighting and/or signalling device and motor vehicle including such a device - Google Patents

Description

The present invention relates to lighting and / or signaling devices, including headlights and rear lights of motor vehicles.

Although it is particularly suitable for motor vehicles, the present invention is however not limited to this application and could equally well be implemented for example in fixed lighting devices of buildings.

It is known that, because of a difference in temperature between the air inside a front headlight of a motor vehicle and the air outside it, the humidity present in the Inner air condenses on contact with the cooler projector glass. Water droplets are then formed on the inside of the ice facing the inside of the projector. Such a phenomenon is frequently observed for outside air temperatures below 5 ° C. When the outside air temperature drops below 0 ° C, these water droplets freeze to a frost layer on the inside of the ice.

It is also known that the use of incandescent lamps in the front projectors causes a very rapid evaporation of the water droplets formed on the ice, thanks to the heat release produced by these lamps.

However, the recourse more and more frequently to new light sources offering better quality lighting while reducing the associated power consumption is accompanied, in return, a reduction of the thermal clearances inside the projector that are not enough. more to evaporate the drops of water formed on the ice.

To overcome this drawback, the patent document US7262388B2 proposes to mount a heater on the casing of a vehicle headlamp.

However, in addition to the high electricity consumption of such a heater, the arrangement of it with respect to the projector glass does not allow a rapid suppression of the formed condensation. This is incompatible with the expectations of users who wish to have a lighting system of their vehicle fully operational at the ignition of the latter.

The present invention aims to remedy this drawback and, in particular, to prevent the formation of droplets and frost on the ice of a lighting and / or signaling device, for example mounted on a motor vehicle.

To this end, according to the invention, the lighting and / or signaling device for a motor vehicle, comprising a housing, a transparent element closing, at least partially, the housing and at least one light source disposed in a delimited internal volume by the case and the associated transparent element,
is remarkable in that it comprises means for emitting, in the internal volume, primer particles capable of associating with dust particles and / or water particles suspended in said internal volume, for the ion-particle aggregates of water or dust are removed by gravity.

Thus, thanks to the invention, the primer particles emitted and the particles of dust and / or water floating inside the internal volume of the lighting and / or signaling device attract each other to then combine them. As soon as a primer particle is associated with one or more particles of dust or water, the heavier aggregate of particles thus formed is drawn downwards by the effect of gravity. In doing so, the dust particles and the water particles present in the air are removed by gravity inside the internal volume of the lighting and / or signaling device, thereby drying out the indoor air and prevents the formation of droplets on the face of the ice facing the internal volume, whatever the temperature of the indoor air.

In an embodiment according to the invention, the primer particles emitted are positive and / or negative ions.

Alternatively or in addition, the primer particles emitted are silver iodide particles. Indeed, the crystalline structure of silver iodide is close to that of snow, so that silver iodide causes a reaction aligning water particles in a structure similar to that of ice, freezing the droplets of water and forcing their precipitation.

Preferably, the particle emitting means are arranged in the rear part, preferably below, of the housing, so as to prevent them from interfering with the light beam emitted by the light source.

In addition, since the housing has a rear base facing the transparent element, the transmission means can advantageously be mounted on a portion bottom of said rear background.

In particular, the lower portion of the rear background comprising the emission means is preferably arranged below the light source, in order to prevent, or at least limit, an accumulation of water particles on the support on which is mounted the light source.

In addition, the device comprising a reflector interposed between the transparent element and the housing, the transmission means are advantageously arranged behind the reflector, between the latter and the housing, to prevent the formation of a fog in front of the emitted light beam by the light source.

Preferably, the reflector splits the internal volume in two to define a front sub-volume and a rear sub-volume in communication with each other, the transmitting means being disposed within said rear sub-volume. .

Furthermore, said device comprises means for evacuating outside the internal volume the dust particles and / or water associated with the primer particles.

Advantageously, the evacuation means are arranged in the lower rear part of the housing.

Preferably, said device comprises a reservoir in communication with the evacuation means, which is intended to collect the particles of dust and / or water associated with the primer particles.

In addition, the evacuation means advantageously comprise at least one opening formed in one of the walls of the housing, which can be closed by a breathable membrane (16), for example of the GORE TEX (registered trademark) type, able to let the water particles associated with the seed particles from the internal volume to the outside thereof.

Alternatively, the evacuation means may comprise at least one channel, preferably in a baffle.

Furthermore, the present invention also relates to a motor vehicle which comprises at least one lighting and / or signaling device as described above.

In addition, the primer particle emission means are preferably activated at least during a part of stopping the operation of said vehicle.

The sole figure of the appended drawing will make it clear how the invention can be realized. In this figure, identical references designate similar elements.

The figure 1 shows, in a schematic cross section, an example of lighting and / or signaling device according to the present invention.

On the figure 1 Diagrammatically a lighting and / or signaling device before 1 of a motor vehicle (hereinafter referred to as a front projector) according to the present invention.

Of course, the present invention is not limited to front headlamps, but also applies to motor vehicle taillights and, more generally, to any device capable of emitting light in which the formation of condensation can be observed.

Subsequently, the notions of "superior" and "inferior" refer, respectively, to the lower and upper parts of the figure 1 . Similarly, the notions "before" and "backward" are defined in relation to the left and right sides of the figure 1 .

As shown in figure 1 , the front projector 1 comprises a housing 2 (also referred to as "rear block" or "optical block") which serves in particular as a support part on which are in particular mechanically reported one or more light sources 3 (only one is represented on the figure 1 ), a reflector 4 and a mask 5.

The housing 2 also connects the front projector 1 to the vehicle (not shown). For this, the housing 2 comprises a plurality of attachment points (which are associated for example threads) to ensure a stable mechanical connection with the vehicle.

In addition, the housing 2, which has the general shape of a bowl, comprises a rear base 6 and a peripheral strip 7, of which only the upper parts 7A and 7B lower are visible on the figure 1 . The peripheral strip 7 extends in a direction substantially orthogonal to the rear base 6.

The projector 1 further comprises a transparent element 8 through which one or more beams of the light source 3 pass to illuminate the route taken by the vehicle. This is for example a glass ice or even polycarbonate. Element 8 is transparent in that it allows the passage of at least 75% of the luminous flux of the light rays emitted by the light source 3 which reaches it. In other words, the transparent element 8 degrades the photometric function of the light source 3 by at most 25%.

In addition, the transparent element 8 is formed of a front wall 8A, exposed to the air flow outside the projector 1, and a peripheral skirt 8B, which extends along the contour of the front wall 8A and which is intended to be secured to the housing 2 at the free peripheral edge 9 of the strip 7. In other words, the free edge 9 of the housing 2 forms a support in the form of a groove against which can be applied the peripheral skirt 8B of the transparent element 8. Thus, once mounted, the transparent element 8 closes the housing 2, which defines an internal volume Vi within which is housed the light source 3.

Moreover, as shown in figure 1 , the front projector 1 comprises a single light source 3. Of course, alternatively, one could consider several light sources.

Although it may be in the form of a discharge lamp using a Xenon type gas, the light source 3 advantageously comprises one or more light-emitting diodes at the origin of the light rays forming the beam projected on the road.

In addition, the light source 3 is mounted on a support 10 formed, for example, by a printed circuit. The reflector 4 in the form of a shell, at the bottom of which the light source 3 is arranged, makes it possible to direct the light rays emitted by the latter towards the transparent element 8. A diopter 11, for example a lens, is furthermore arranged in front of the light source 3, so as to focus, around a given direction, the multitude of light rays emitted by it.

According to the invention, as shown in figure 1 , the front projector 1 also comprises an ionization device 12 for emitting, in the internal volume Vi, positive and / or negative ions 13 capable of associating with dust particles and / or water particles (no represented) in suspension in the internal volume Vi.

In the example of the figure 1 , the ionization device 12 is attached to the rear base 6 of the housing 2. In particular, it is advantageously mounted on the lower portion 6A of the rear base 6, below the support 10 of the light source 3. Of course, the ionization device 12 could alternatively be fixed on the portion upper 6B rear end 6.

The reflector 4 and the mask 5, interposed between the transparent element 8 and the housing 2, divide the internal volume Vi in two, which defines a subvolume before Vs1 and a rear subvolume Vs2 in communication with each other. the other. The ionization device 12 is thus housed inside the rear sub-volume Vs2.

Thus, thanks to the invention, the ions are combined in particular with the water particles suspended in the air inside the internal volume Vi of the projector 1, each ion being able to associate with one or more particles of water according to its nature. The ion-water particle aggregates thus formed are attracted to the lower part 7B of the peripheral strip 7 under the effect of the gravitational force. The air present inside the volume Vi is thus dried, which prevents the appearance of a condensation layer on the transparent element 2, regardless of the temperature difference between the indoor air and the air outside.

In addition, the arrangement of the ionization device 12 in the lower portion 6A of the rear bottom 6 of the housing 2 makes it possible to confine the emission of the particles in the rear sub-volume Vs2 and to limit the emission of the particles into the sub-volume. volume before Vs1, which could degrade the efficiency of the light source 3. The device can be associated with vents by means of baffles to ensure drying of the air arriving ventilation and entering the lighting device and or signaling, to limit the increase of the humidity level in it.

In addition, such an arrangement of the ionization device 12 makes it possible to limit the deposition, by gravity, of ion-particle aggregates of water or dust on the support 10 of the light-sensitive light source 3, these aggregates forming essentially in the vicinity of the ionization arrangement 12.

For increased efficiency, it is preferable to activate the ion emitting means 12 when stopping the operation of the vehicle, either for a predetermined duration or during the entire absence of operation of the vehicle. For this, appropriate means for controlling the ion-emitting means 12 may be provided. It goes without saying that an implementation of the ion emission means during the operation of the vehicle is also possible.

Furthermore, according to the invention, the projector 1 also comprises means 14 for discharging outside the internal volume Vi the particles of dust and / or water agglomerated with the ions 13.

The evacuation means 14 are arranged in the rear part of the projector 1 in the vicinity of the ionization device 13. They are in the form of an opening 15 (for example a slot extending over a part of the width of the projector 1) which is provided in the lower part 7B of the peripheral strip 7.

In addition, the face of the opening 15 facing the sub-volume Vs2 is covered by a breathable membrane 16, for example of GORE TEX type, capable of passing the aggregates formed of ions and water particles associated with the internal sub-volume Vs2 towards the outside (the arrow F symbolizing the displacement of the aggregates formed).

In addition, the front projector 1 advantageously comprises a removable reservoir 17 connected to the evacuation means 14 and adapted to receive the dust particles and / or water associated with the ions 13. In this way, the reservoir 17 can be emptied, once its maximum filling level is reached.

Alternatively or in addition, the transmitting means could emit silver iodide particles, so as to dry the air inside the volume Vi of the projector before 1 in a manner similar to that presented for the In the latter case, the transmitting means could be in the form of diffusion means.

Claims (16)

1. Lighting and/or signalling device for a motor vehicle, comprising a housing (2), a transparent element (8) at least partially closing off the housing (2) and at least one light source (3) disposed in an internal space (Vi) delimited by the housing (2) and the associated transparent element (8),
   characterised by the fact that it comprises means (12) for emitting, in the internal space (Vi), initiation particles (13) able to be associated with dust particles and/or water particles in suspension in said internal space (Vi), so that the aggregates of initiation particles (13) and water or dust particles are eliminated by gravity.
2. Device according to the preceding claim, in which the initiation particles (13) emitted are ions.
3. Device according to one of claims 1 or 2, in which the initiation particles emitted are silver iodide particles.
4. Device according to one of the preceding claims, in which the means of emitting particles (12) are arranged in the rear, preferably lower, part of the housing (2).
5. Device according to the preceding claim, in which, the housing comprising a rear end (6) opposite the transparent element (8), the emission means (12) are mounted on a lower portion (6A) of said rear end (6).
6. Device according to the preceding claim, in which the lower portion (6A) of the rear end (6) comprising the emission means (12) is arranged below the light source (3).
7. Device according to one of the preceding claims, comprising a reflector (4) interposed between the transparent element (8) and the housing (2), in which the emission means (12) are arranged behind the reflector (4), behind the latter and the housing (2).
8. Device according to the preceding claim, in which the reflector (4) divides the internal space (Vi) into two in order to define a front subspace (Vi1) and a rear subspace (Vi2) in communication with each other, the emission means (12) being disposed inside the rear subspace (Vi2).
9. Device according to one of the preceding claims, comprising means (14) for discharging outside the internal space (Vi2) the dust and/or water particles associated with the initiation particles (13).
10. Device according to the preceding claim, in which the discharge means (14) are disposed in the lower rear part (7B) of the housing (2).
11. Device according to one of claims 9 or 10, comprising a reservoir (17) in communication with the discharge means (14), which is intended to collect the dust and/or water particles associated with the initiation particles (13).
12. Device according one of claims 9 to 11, in which the discharge means (14) comprise at least one opening (15) provided in one of the walls (7B) of the housing (2).
13. Device according to the preceding claim, in which the opening (15) is closed off by a breathing membrane (16), able to allow the water particles associated with the initiation particles (13) to pass from the internal space (Vi) to the outside thereof.
14. Device according to one of claims 9 to 12, in which the discharge means (14) comprise at least one channel, preferably in a chicane.
15. Motor vehicle,
    characterised by the fact that it comprises at least one lighting and/or signalling device (1) as specified in one of claims 1 to 14.
16. Motor vehicle according to the preceding claim, in which the means (12) for emitting initiation particles are activated at least during part of the stoppage of functioning of said vehicle.

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