EP1422471A2 - Elliptical vehicle headlamp emitting different light beams - Google Patents

Abstract

The headlamp (10) comprises an elliptical reflector (14) and a converging lens. Two (24,26) may be inserted along the optical axis (AA) of the headlamp, between the reflector and the lens. The masks may be pivoted, enabling the beam to be adjusted between dipped and full positions. The headlamp (10) for a motor vehicle comprises a light source (16) and an elliptical reflector (14) whose first focus is situated near to the source (16). A converging lens is provided with its focal plane passing near to the second focus of the reflector. First and second masks (24,26) may be inserted along the optical axis (AA) of the headlamp, between the reflector and the lens. The second mask (26) is mounted to pivot between two positions about a second axis which itself is mounted on the first mask. The first mask (24) is rectangular and is mounted to pivot about a first axis, such that it and the second mask may be raised into a position near to the optical axis of the headlamp. This allows the beam to be adjusted between dipped and full positions.

Description

The present invention relates to projectors of the elliptical type. for motor vehicles.

Elliptical type headlamps comprise in known manner a light source, an elliptical type reflector including a first focus is located near the source, a converging lens whose a focal plane passes in the vicinity of a second focus of the reflector.

When such a headlamp must form a cut-off beam, such than a passing beam or a fog beam, it includes a cover interposed at the second focal point of the reflector, which obscures the part of the radiation, which would otherwise spread over this cut.

In such a type of projector, it is then difficult to modify the cut profile. Such modification should be considered especially when a projector, designed for example for a sense of right-hand traffic, must form a light beam suitable for left hand traffic.

Such a modification of the cutoff profile can also be considered when you want to perform lighting functions perfected.

Indeed, in the field of vehicle lighting, we seeks to develop new services to improve the quality of the lighting provided by the vehicle headlights, in particular under certain specific traffic conditions, for example when the vehicle is traveling in the city, or when it is traveling in time rainy, or when traveling on the highway. These new functions advanced lighting are usually grouped under the AFS function names for "Advanced Front Lighting System ”.

A known solution to modify the profile of the cut consists to intervene on the projector cover to modify its profile cut.

We know, for example from document EP-A-0.381.851, a elliptical projector of the type comprising a first cover provided between the reflector and lens, which has an edge defining a first profile particular cut-off for the light beam emitted, and a second cover disposed on the first cover and selectively movable between two positions, a first position in which an edge of the second cover is positioned on the path of the light rays to form with the first hides a light beam with a second cut profile particular, and a second position in which said edge of the second cover is substantially positioned outside the path of the light rays to form a light beam with the first cut profile.

In addition, a solution to selectively perform a function crossing or a road function, consists of rotating the cover mobile of the projector to position it respectively in or out of the light beam emitted.

In this regard, we already know a projector of the elliptical type which has a pivoting cover between a crossing position and a road position, around an axis generally horizontal and parallel to the optical axis.

The cover is pivotally mounted on a frame part of the projector, at one of its lateral sides, and the movement of the cover is pivoted so that it always remains in the vertical plane transverse to the optical axis where it is in position crossing.

Such a projector has several drawbacks. First of all, with such a cover arrangement pivoting about an axis parallel to the optical axis, taking into account the small space available in the housing of the projector, below the cover, it is impossible to release completely cover the emitted light beam, on the side of the axis of pivoting of said cover.

So when this projector is operating on the way, the beam emitted light has a reduced light intensity due to the fact that part of the cover, located on the side of the pivot axis of this last, always remains on the path of the light rays emitted. In addition, mounting the pivoting cover on one of its lateral sides, generates a bad balance of the cache which is not supported by the other side. Finally, such a pivoting cover arrangement requires the use of a bulky and powerful actuating means for quickly return the cover to the road position towards the crossing position.

To resolve these problems, document FR-A-2,796,449 offers an elliptical type projector which has a main cover mounted pivoting about a transverse axis and which includes a cover secondary mounted pivoting about an axis parallel to the optical axis.

When the main cover is in the concealed position, it is say in a transverse plane, and when the secondary cover is in retracted position down, the spotlight creates a beam lighting with a first cut-off profile.

When the pivoting of the secondary cover towards its high concealment position, the main cover occupying its position of concealment, then the projector achieves a lighting beam with a second cutoff profile different from the first.

This type of projector is not completely satisfactory. In indeed, the secondary cover is provided to modify the cut made by the main cover in the lighting beam by increasing the obscured surface. Therefore, the secondary cache does not allow create a light beam with a cut-off profile specific with a less obscured lighting area compared to at the first cut profile.

In addition, the secondary cover being of small dimensions, the thermal stresses to which it is subjected inside the projector may change its geometry and cause projector malfunctions. The thermal constraints mentioned above also make it difficult to index the different positions of the secondary cover. In addition, the route function is difficult to achieve in because of the proximity of the pivot axis of the secondary cover with the upper part of the main cover, this proximity being imposed by the optical conjugation of the lens with the reflector.

The present invention is placed in this context and aims to remedy these drawbacks by proposing a projector equipped with movable covers so as to generate different beams lighting, which is simple, reliable and economical.

To this end, the invention provides a vehicle headlamp automobile, comprising a light source, a reflector of the type elliptical whose first focus is located near the source, a converging lens of which a focal plane passes in the vicinity of a second reflector focus, first and second covers which are inserted axially, along the optical axis of the projector, between the reflector and the lens, of the type in which the first cover is pivotally mounted around of a transverse axis between two extreme positions.

According to the present invention, the second cover is mounted at pivoting around a second pivot axis arranged on the first cover, the first cover is generally rectangular, and the second axis pivot is arranged along the upper transverse edge of the first cache.

• le second cache comporte au moins deux ailes planes ;
• le second axe de pivotement passe par la zone de jonction des ailes du second cache ;
• le second cache est mobile en rotation entre au moins deux positions, dans chacune desquelles une des ailes est dans le prolongement du premier cache ;
• dans chacune des positions du second cache, le bord libre de l'aile se trouvant dans le prolongement du premier cache est situé au voisinage immédiat de l'axe optique du projecteur ;
• le bord libre de chaque aile forme un bord de coupure pour le faisceau d'éclairage émis par le projecteur ;
• les bords de coupure formés sur chaque aile sont différents ;
• le bord de coupure d'une aile est prévu pour réaliser un faisceau lumineux à coupure adapté pour un sens de circulation à droite, et en ce que le bord de coupure d'une autre aile est prévu pour réaliser un faisceau lumineux à coupure adapté pour un sens de circulation à gauche ;
• le bord de coupure d'une aile est prévu pour réaliser un faisceau lumineux à coupure adapté pour une fonction d'éclairage perfectionné.

According to other characteristics of the invention:

• the second cover comprises at least two flat wings;
• the second pivot axis passes through the junction zone of the wings of the second cover;
• the second cover is movable in rotation between at least two positions, in each of which one of the wings is an extension of the first cover;
• in each position of the second cover, the free edge of the wing located in the extension of the first cover is located in the immediate vicinity of the optical axis of the projector;
• the free edge of each wing forms a cutting edge for the lighting beam emitted by the projector;
• the cut edges formed on each wing are different;
• the cut-off edge of one wing is designed to produce a cut-off light beam suitable for a right-hand traffic direction, and in that the cut-off edge of another wing is provided to produce a cut-off light beam suitable for a left-hand traffic direction;
• the cutting edge of a wing is provided to produce a cut-off light beam suitable for an improved lighting function.

• la Figure 1 est une vue en perspective éclatée qui représente un projecteur elliptique réalisé conformément aux enseignements de l'invention ;
• la Figure 2 est une vue en coupe du projecteur de la Figure 1, le premier cache et le second cache occupant chacun leur première position ;
• la Figure 3 est une vue similaire à celle de le Figure 2, dans laquelle le premier cache occupe sa deuxième position et le second cache occupe sa première position ;
• la Figure 4 est une vue similaire à celle des Figures 2 et 3, dans laquelle le premier cache occupe sa première position et le second cache occupe sa deuxième position ;
• la Figure 5 est une vue similaire à celle des Figures 2 à 4, dans laquelle le premier cache et le second cache occupent tous deux leur deuxième position.

Other characteristics and advantages of the invention will appear on reading the detailed description which follows for the understanding of which reference will be made to the appended drawings among which:

• Figure 1 is an exploded perspective view which shows an elliptical projector produced in accordance with the teachings of the invention;
• Figure 2 is a sectional view of the projector of Figure 1, the first cover and the second cover each occupying their first position;
• Figure 3 is a view similar to that of Figure 2, in which the first cover occupies its second position and the second cover occupies its first position;
• Figure 4 is a view similar to that of Figures 2 and 3, in which the first cover occupies its first position and the second cover occupies its second position;
• Figure 5 is a view similar to that of Figures 2 to 4, in which the first cover and the second cover both occupy their second position.

Preliminary, it will be noted that from one Figure to another the identical or similar elements are referenced to the extent of possible by the same reference signs.

In the Figures, a headlight 10 for a vehicle is shown. automobile which comprises a lamp 12 mounted in the bottom of a reflector 14 of the elliptical type such that the light source 16, ie the filament of an incandescent lamp or the electric arc of a discharge lamp as in the example shown, is located at neighborhood of a first focus of the reflector 14.

In the following description, a non-limiting use will be made of orientation from back to front, along the optical axis A-A of the projector 10, which corresponds to a right-to-left orientation considering the Figures 2 to 5, i.e. in the direction of propagation of the rays bright at the exit of the projector. The optical axis A-A is generally parallel to the longitudinal axis of the vehicle that the headlight 10 equips.

The optical axis A-A is here substantially horizontal and it can be defined for example by the two focal points of the reflector 14.

We will also use, without limitation, an orientation from top to bottom along a vertical axis, considering Figures 2 to 5.

We define a transverse direction which is substantially horizontal and orthogonal to the optical axis A-A.

The projector 10 includes a converging lens 18, for example example plano-convex, which is mounted, in the front, in a part intermediate 20 of the projector 10 fixed on a transverse surface front 22 of reflector 14.

The focal plane of the lens 18 passes in the vicinity of the second focal point of the reflector 14.

The projector 10 has a first cover 24 and a second cover 26 which are interposed between the reflector 14 and the lens 18, at the vicinity of the focal plane of the lens 18.

All the elements described above constitute a block spotlight optics 10 which is for example mounted so classic in a case (not shown) closed by a glass.

In accordance with the teachings of the present invention, the first cover 24 and the second cover 26 are pivotally mounted by relative to reflector 14.

More specifically, the first cover 24 is mounted at pivoting about a pivot axis A1 formed on a plate 28 interposed axially between the reflector 14 and the intermediate piece 20.

In the embodiment shown, the first cover 24 a broadly shaped like a rectangular plate and it has two edges 30, 32 substantially transverse and, here by way of example not limiting, two substantially vertical lateral edges which give the plate a generally rectangular shape.

The geometric pivot axis A1 of the first cover 24 is arranged here along the lower transverse edge, or transverse edge of pivot 30.

For its pivoting mounting, the first cover 24 comprises for example at each end of the transverse edge of pivoting 30 a section of shaft which, on one side, is mounted free at rotation in a bearing of the intermediate framework piece 28 and of the other side is integral with rotation of the drive shaft of a actuator, such as an electric motor or an electromagnet (not represented).

The first cover 24 is thus movable between two positions extremes, a first substantially vertical position, and a second tilted forward position.

The second cover 26 is pivotally mounted around an axis of pivoting A2 arranged along the upper transverse edge of the first cover 24, or transverse pivoting edge 32.

More specifically, in the example shown, the second cover 26 is in the form of an "L" angle, it is formed by two wings generally rectangular planes 26A and 26B forming between them a angle, and it is likely to pivot on the first cover 24 around the axis A2 passing through the junction zone of the two wings 26A and 26B.

The second cover 26 is thus movable in rotation relative to the first cover 24, between two extreme positions, in which a of the two wings 26A or 26B is substantially in the extension of the first cover 24.

Thus, when the first cover 24 occupies its first position vertical, the second cover also has one of its wings 26A or 26B in vertical position.

In this position, the respective dimensions of the first cover 24 and wings 26A or 26B are such that the free edge of wing 26a or 26B is located in the immediate vicinity of the optical axis A-A, and at the immediate vicinity of the second focus of the reflector 14.

In known manner, when the lamp 12 is on, the rays light reflected by the reflector 14 are concentrated in a spot light at the second focus of the reflector 14, that is to say on the edge of one of the wings 26A or 26B when the first cover is in position vertical, the lens 18 forming an image of this light spot infinity.

The free transverse edge of each wing 26A or 26B opposite the transverse pivot edge along the axis A2 forms an edge of cutoff, i.e. it defines a cutoff profile for the beam lighting emitted by the projector 10 when the first cover 24 occupies its vertical position.

It can thus be provided that the cutting edge of the wing 26A is designed to produce a cut-off light beam suitable for one direction traffic on the right, while the cutting edge of wing 26B will be designed to produce a cut-off light beam suitable for one direction left hand traffic.

Under these conditions, according to the relative position of the first and second covers 24 and 26, different light beams can be obtained. For example, if the first cache 24 is in its first vertical position, and if the second cover 26 is also in its first position in which the wing 26A is in line with the first cover 24, as shown in Figure 2, the projector 10 will generate a crossing light beam adapted for one direction traffic on the right.

On the other hand, if the first cover 24 is in its first position vertical, and if the second cover 26 is in its second position in which the wing 26B is in the extension of the first cover 24, thus as shown in Figure 4, the projector 10 will generate a passing beam of light adapted for a direction of circulation at left.

Regardless of the position of the second cover 26, if the first cover 24 occupies its second position, and that it is retracted towards the front, as shown in Figures 3 and 5, the projector 10 will generate an unbroken light beam, i.e. a beam of road.

In a variant, it will be possible to provide that the cutting edge of the wing 26B of the second cover is provided so that the projector 10 achieves a “AFS” type lighting function. For example, it can “Adverse Weather Lighting” type lighting function, ie a lighting function for traffic in rainy weather which limits glare produced in the direction of oncoming vehicles opposite.

Of course, the cutting edge of the wing 26B of the second cover 26 could be provided to perform another type of lighting function, for example a lighting function for city traffic ("Town Lighting ") in which the occultation is more important than in lighting in rainy weather, or a lighting function for highway traffic.

We can also provide that the second cover 26 includes more than two wings, for example one wing having a cutting edge for a beam adapted to a right-hand traffic direction, a wing having a cutting edge for a beam adapted to a direction of left-hand traffic, a wing with a cut-off edge for beam suitable for driving in rainy weather, and a wing having a cutting edge for a beam suitable for traffic on highway.

Claims (9)

Projector (10) for a motor vehicle, comprising a light source (16), a reflector (14) of the elliptical type, a first focus of which is located in the vicinity of the source (16), a converging lens (18) of which a focal plane passes in the vicinity of a second focus of the reflector (14), a first (24) and a second (26) covers which are interposed axially, along the optical axis (AA) of the projector (10), between the reflector (14) and the lens (18), of the type in which the first cover (24) is pivotally mounted about an axis (A1) substantially transverse between two extreme positions, characterized in that the second cover (26) is pivotally mounted around a second pivot axis (A2) arranged on the first cover (24), in that the first cover (24) is generally rectangular, and in that the second pivot axis (A2) is arranged along the edge upper transverse of the first cover (24). Projector according to claim 1, characterized in that the second cover (26) comprises at least two planar wings (26A, 26B). Projector according to claim 2, characterized in that the second pivot axis (A2) passes through the zone of junction of the wings (26A, 26B) of the second cover (26). Projector according to claim 3, characterized in that the second cover (26) is rotatable between at least two positions, in each of which one of the wings (26A, 26B) is in line with the first cover (24). Projector according to claim 4, characterized in that , in each of the positions of the second cover (26), the free edge of the wing (26A, 26B) lying in the extension of the first cover (24) is located in the immediate vicinity of the optical axis (AA) of the projector (10). Projector according to claim 5, characterized in that the free edge of each wing (26A, 26B) forms a cutting edge for the light beam emitted by the projector (10). Projector according to claim 6, characterized in that the cutting edges formed on each wing (26A, 26B) are different. Headlamp according to claim 7, characterized in that the cutting edge of a wing (26A) is designed to produce a light beam with cutoff suitable for a right-hand traffic direction, and in that the cutoff edge of a another wing (26B) is provided to produce a cut-off light beam suitable for a left-hand traffic direction. Projector according to claim 1, characterized in that the cutting edge of a wing (26A, 26B) is provided to produce a cut-off light beam suitable for an improved lighting function.

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