EP3212995B1 - Multi-module motor vehicle headlight with moving mirrors actuated by a single motor - Google Patents

Description

The field of the present invention is that of automobile equipment and, more particularly, that of light projectors for these motor vehicles.

Motor vehicle headlamps generally comprise a reflector in which are arranged a light source and means for controlling the shape of the beam emitted by said source to adapt it to the circumstances of driving. The reflectors generally take the form of a paraboloid or an ellipsoid of revolution, for which the light source is positioned at the level of the focal point or one of the focal points of these surfaces. In the case of an ellipsoid, the light source is conventionally positioned at a first focus and a lens is positioned on the optical axis so that its own focus coincides with the second focus of the ellipsoid. In order to reduce the overall dimensions of the headlight, it has been imagined to reduce its vertical extension and to retain only half of an ellipsoid to form the reflector. In some embodiments, a mirror is then placed at the level of the second focal point, to reflect upwards the light rays which arrive there.

It is known, moreover, to use a cut-off strip allowing various phases of occultation of the light beam. The bar is electrically actuated to move, on command, between at least two angular positions in which it more or less obscures the light beam. This makes it possible to limit the range of the headlamp, for example to that of dipped beam headlights, called low beam position, so as not to dazzle drivers traveling in the opposite direction, or even to that of main beam headlights, called high beam position, in which it does not there is no concealment. This technology is commonly used with headlamps comprising a high-power light source, such as halogen or xenon lamp headlamps, for which the loss of light output due to the interception of the flux by the strip is not really detrimental . US

2012/140502 A1 and KR 2011 0115017 A disclose multi-module motor vehicle headlamps known from the prior art.

Furthermore, the technology of automobile headlamps is currently tending towards the use of light sources consisting of light-emitting diodes called LED diodes (for Light-Emitting Diode, for light-emitting diodes) for their reduced cost and their better life. On the other hand, the light power emitted by these devices remains limited for the moment and it is necessary to use it as well as possible. It is therefore desirable to be able to dispense with the cut-off cover which absorbs, in the dipped beam position, substantially half of the luminous flux emitted. To meet this need, it is possible to make mobile, in the case of an ellipsoid, the beam deflection mirror between a position corresponding to the dipped headlights, where it returns all the rays to the top of the reversing lens, and a position corresponding to the high beam, where it does not interfere with the light rays and lets them reach the bottom of the lens.

Finally, it may be necessary to implement several projectors, placed parallel to each other to achieve the desired light beam, whether for the purpose of obtaining the desired light power, to give a particular shape to the beam or to modulate the distribution in its lighting density.

This multiplicity of projectors, associated with distinct mobile mirrors and with mechanisms for setting these mirrors in motion makes the production of LED projectors quite complex and it is desirable to simplify their production. The object of the present invention is therefore to remedy these drawbacks by proposing, in particular for multiple headlights with semi-elliptical reflectors, a simplified actuation device.

To this end, the subject of the invention is a multi-module headlamp for a motor vehicle, each module constituting said headlamp comprising at least one light source and at least one movable beam interception member capable, depending on its position, of intercepting or to allow part of the light beam from said source to pass, characterized in that the interception members of at least two modules are common or actuated by a common setting means.

This pooling makes it possible to reduce the number of parts necessary for controlling the passage from main beam to dipped beam, and vice versa, and simplifies the production of the headlamp.

According to the invention, each module comprises a reflector, said source of said module being positioned at a point, called first focus, of said reflector and said reflector having a shape such that at least part of the rays coming from said source converges after reflection towards a point, called second focus, of said reflector.

According to the invention, the reflectors of said two modules are open portions of ellipsoids or half-ellipsoids extending above a plane of symmetry of said ellipsoid. The foci of the reflector are then the foci of the ellipsoid.

Said two modules are preferably positioned side by side, their optical axes being parallel, and their second focal points have the same abscissa on said optical axes. This proximity simplifies, for its part, the production of the control means for the passage from main beam to dipped beam, and vice versa.

In a particular embodiment, the reflectors of said two modules are half-ellipsoids extending above a plane of symmetry of said ellipsoid and the beam interceptor in said two modules is a reflecting surface oriented upwards with respect to the plane of symmetry of said ellipsoid. This configuration has the advantage of being more compact and more easily accommodated in a motor vehicle.

Preferably, the reflective surfaces of the two modules are plane mirrors placed, longitudinally, substantially at the level of the second focus of their reflector, said modules further comprising a device for reversing its beam to redirect the light flux from the second focus into a direction parallel to the optical axis.

Advantageously, the reversing member is, for at least one module, a lens whose focal point is positioned longitudinally substantially at the level of said second focal point of the corresponding reflector.

Advantageously, said plane mirrors are rotatable around the same axis, oriented perpendicular to the optical axis.

More advantageously, the axis of rotation comprises a toothed sector extending in a plane substantially perpendicular to the longitudinal direction of the axis of rotation. Preferably, the axis of rotation is driven by a single motor meshing with said toothed sector.

Even more preferably, the motor supplies a torque against a rotating return spring. This device guarantees the return of the headlight to dipped beam in the event of a failure of the motor for actuating the beam interception means. In another embodiment, said reflective surface is a complex surface capable of directly generating the shape of an automobile headlight beam from at least part of the light beam coming from said second focal point.

In a preferred embodiment, the light source of at least one module is a light-emitting diode.

The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the detailed explanatory description which follows, of an embodiment of the invention given by way of example. purely illustrative and non-limiting example, with reference to the accompanying schematic drawings.

• la figure 1 est une vue schématique d'un projecteur elliptique de véhicule automobile,
• la figure 2 est une vue schématique d'un projecteur semi-elliptique à miroir mobile, en position de feux de route,
• la figure 3 est une vue du projecteur de la figure 2, en position de feux de croisement,
• la figure 4 est une vue en perspective d'un projecteur mutimodules selon l'invention, à miroirs mobiles, dans la position des feux de route,
• la figure 5 est une vue du projecteur de la figure 4, dans la position des feux de croisement, et
• la figure 6 est une vue en coupe longitudinale du projecteur de la figure 4.

In these drawings:

• the figure 1 is a schematic view of an elliptical motor vehicle headlamp,
• the figure 2 is a schematic view of a semi-elliptical headlamp with moving mirror, in the main beam position,
• the picture 3 is a projector view of the figure 2 , in dipped beam position,
• the figure 4 is a perspective view of a multi-module headlamp according to the invention, with moving mirrors, in the main beam position,
• the figure 5 is a projector view of the figure 4 , in the position of the dipped headlights, and
• the figure 6 is a longitudinal sectional view of the headlight of the figure 4 .

By referring to the figure 1 , we see a motor vehicle headlamp 1 of the prior art which is constituted by a reflector 2, having substantially the shape of an open portion of an ellipsoid, inside which is placed a light source S, and by a convergent lens 3 which is positioned in front of the reflector. The light source S is positioned at the first focus of this ellipsoid, on the bottom side of the reflector 2, and it emits over the entire solid angle formed by the ellipsoid. All the light rays emitted are directed, after reflection on the reflector 2, in the direction of the second focus F of the ellipsoid. The lens 3 is positioned longitudinally on the optical axis xx of the projector 1 in a position such that its focal point is approximately at the level of the second focal point F of the ellipsoid. In this way the light rays coming from the reflector 2 are straightened to be substantially parallel to the optical axis at the output of the lens 3. A light beam is thus obtained which illuminates the road in the distance, in a high beam position. It is then necessary to provide a cut-off mechanism (not shown) to eliminate, before it passes through the lens, the lower part of the beam and perform the dipped beam function.

The figures 2 and 3 show a semi-elliptical headlamp with a moving mirror, respectively in the main beam and dipped beam positions.

Unlike the figure 1 the reflector 12 comprises, here, only the upper half of the ellipsoid portion of the previous case. Consequently, the light source only emits over a solid angle of 2π steradians, ie, in section along a vertical plane passing through the optical axis, as shown in the figures, over a sector of 180° directed upwards. This configuration is particularly well suited to a light source formed by light-emitting diodes LED, which only emit over a solid angle of 21π steradians.

As before, the luminous flux is directed, after reflection on the reflector 12, towards the second focus F of the ellipsoid then towards a converging lens 3. Due to this emission over 2π steradians, the light beam is only directed towards half lower part of the lens 3. The shape of the lens and/or the position of its focal point with respect to the second focal point F of the ellipsoid, is such that in the absence of any means of derivation of the beam, the latter is redirected towards the front.

But, as can be seen on the figures 2 and 3 , a movable mirror 4 is positioned at the level of the second focus F. Its reflective surface is directed upwards so as to be able to intercept the luminous flux coming from the reflector 12. This mirror 4 is movable around a horizontal axis so as to position its reflective surface, either in a horizontal plane passing through the optical axis xx, or, in a plane inclined forwards with respect to the horizontal, in a so-called retracted position.

On the figure 2 , the mirror 4 is inclined with respect to the horizontal plane and is positioned entirely outside the luminous flux, thus allowing all the rays to pass in the direction of the lens 3. These pass through the lower part of the lens and are straightened towards up to illuminate the road over a long distance. We thus find ourselves in the position of the main beam headlights, without loss of the light power emitted by the source S.

On the other hand, on the picture 3 , the mirror 4 is in a horizontal position and its longitudinal span is sufficient to intercept all the rays which come from the reflector 12. All these rays are reflected upwards by the mirror 4 and are redirected by the latter towards the upper part of the lens 3. At the exit of the lens, the light rays are sent forwards, but with a downward inflection, which makes it possible to illuminate the road over a given distance. The downward deviation is obtained by the shape given to the lens 3 and/or by shifting the focus of the latter with respect to the second focus of the ellipsoid. We then find ourselves in the position of the dipped headlights, this time again without loss of the light power emitted by the source S.

The figure 4 and 5 show, respectively in high beam and dipped beam configuration, a headlight 11 which consists of two semi-elliptical LED modules 11a and 11b, juxtaposed one beside the other, whose axes of symmetry are parallel. The term “module of a headlamp” is understood to mean a light system in which all or part of the rays coming from a light source are reflected by a reflecting surface in the direction of a focal point called the focal point.

As shown in the figures, each module comprises a reflector, respectively 12a and 12b, in which is placed a light source (not visible), and comprises a mobile mirror, respectively 4a and 4b, which can move in rotation around a horizontal axis, transverse with respect to the direction of the optical axis of the modules. As explained for a single module with reference to figures 2 and 3 , the light sources are positioned at the first focus of each of the reflectors, and the mobile mirrors are positioned at the level of the second focus of these same modules. As a result, the rotation of each of the mirrors makes it possible to produce a beam either in the main beam configuration (mirror lowered), or in the dipped beam configuration (mirror raised).

The contribution of a multiplicity of modules makes it possible, for example, to supply a higher light power, to obtain a greater beam width or even to generate a higher density of light in a part of the beam, in particular in its center. It is nevertheless important that these two (or more) modules work in symbiosis and switch simultaneously from the position of the main beam headlights to the dipped headlights, and vice versa.

To guarantee this simultaneity, the invention recommends, for example, mounting the movable mirrors on a common axis 5 which is oriented perpendicular to the optical axis. This axis is driven in rotation by means of a motor 6 and returned to a rest position, corresponding to the position of the dipped headlights, by a return means, such as for example a torsion spring 7. Such illustrated in the figures, the return spring 7 is mounted on the shaft 5, and bears, on the one hand on the structure of the headlamp 11 and, on the other hand, on a stop 51 carried by the shaft 5. As for motor 6, it is positioned at one end of axis 5, for example under one of the two modules as shown in the figure 4 Where 5 , and is fixed to the structure of the corresponding headlight module 11a.

The figure 6 shows, in sectional side view, the sectional plane located in the vertical plane of symmetry of the ellipsoid of the first module 11a, the detail of the various pieces of equipment and their relative positioning. Unlike the previous figures, the positioning of the lens 3 (not visible) is, here, materialized by its support 8, which is placed on the optical axis xx, downstream of the second focus F of the reflector 12a. The mobile mirror 4a is shown in its retracted position, corresponding to the position of the main beam headlights, and it has free space above it, in order to be able to position itself along the optical axis and thus take the position corresponding to dipped headlights.

The axis of rotation 5, carrying the mirror 4a, rotates in bearings carried by the structure of the projector 11a and extends horizontally below the optical axis. It has an overall cylindrical shape of revolution with however, on either side of each of the mirrors 4a and 4b that it carries, facetted shapes on which support pieces 52 of said mirrors are wedged. These faceted shapes allow the mirrors to be driven in rotation when the axis 5 is itself driven in rotation by the motor 6.

As shown, the axis 5 comprises behind the cutting plane, that is to say between the two modules 11a and 12b of the preceding figures, a toothed sector 9 which is rigidly fixed to it and which extends in a vertical plane, downwards. This toothed sector cooperates with the teeth (not visible) of a drive shaft coming out of the motor 6. In this way a rotation of the motor; in one direction or the other, rotates the toothed sector which drives the axis 5 and, consequently, the mirror 4a via the faceted shapes of the axis 5 and the support pieces 52. A rotation of the motor in the clockwise direction makes the axis 5 turn counterclockwise by compressing the return spring 7. It brings the mirror 4a into the retracted position (as illustrated in the figure 6 ), which corresponds to the high beams. Conversely, turning the motor counterclockwise releases the pressure on spring 7 and lets the mirror return to the horizontal position, which corresponds to dipped headlights.

As illustrated in the figure 4 Where 5 , the toothed sector 9 is unique and the axis of rotation 5 is common to all the mirrors of the modules 11a, 11b, ..., which the projector 11 may have. Whereas in the prior art each projector module has its own motor for actuating its mirror, the invention thus makes it possible, with a minimum of means, to carry out the passage of all the modules from one position (code or road) to the other position and to have this rocker effected simultaneously to all projector modules 11.

Axis 5 has been represented in the form of a cylinder of revolution, with modules positioned side by side in alignment with this axis, but the invention can just as well be carried out with modules which are offset longitudinally or vertically. relative to each other, as long as there is a single means which is able to actuate the mirrors of the different modules.

The invention has been described with a combination of a plane mirror 4 and a lens 3 which reverses the light rays and which gives the desired shape to the beam. Not according to the invention, it could just as well be produced by a single beam reversal member, such as a mirror having a complex shape which returns the light beam forwards, giving it the desired shape. The passage from the configuration of the main beam to the dipped beam remains, in this case, ensured by a displacement of the mirror with a complex shape, which is thus mobile as is the plane mirror of the configuration described.

Similarly, the means for intercepting the beam to pass from main beam to dipped beam has been described in the form of a mobile mirror in rotation around an axis transverse to the optical axis. Not according to the invention, it could just as well be made in the form of a mobile cover which would be mobile in vertical translation or by any other mobile means, provided that it is capable of taking up several positions in which, either it intercepts part of the beam and reflects it, or it lets it pass.

Finally, the projector described has the shape of a half-ellipsoid, but the principle of a common means for actuating the device for intercepting the beam in several modules could also apply in the case of a complete ellipsoid.

Finally, the invention has been described, by way of example, in the case of a headlamp which comprises a reflector, whether the latter is an ellipsoid or a semi-ellipsoid. Not according to the invention, it can just as well be implemented on a headlamp having no reflector, the light emitted by the light source, such as LEDs for example, then being directed directly on the mobile interception means which passes the beam from the main beam to the dipped beam, and vice versa from the dipped beam to the main beam.

Claims (9)

1. Multi-module headlight for a motor vehicle, each module (11a, 11b) forming part of said headlight (11) comprising at least one light source (S) and at least one mobile beam interception device (4a, 4b), capable of intercepting part of the light beam output by said source or allowing it to pass depending on its position, the interception devices (4a, 4b) of at least two modules being activated by a common movement control means, said beam interception devices have reflecting surfaces, the reflecting surfaces of each of the two modules being plane mirrors (4a, 4b), said plane mirrors (4a, 4b) being mounted on a common spindle (5) and being free to move in rotation about said common spindle (5), oriented perpendicular to an optical axis of said headlight (11), each of the two modules (11a, 11b) comprising a reflector (12a, 12b) and a convergent lens (3), the source (S) of said module being positioned at a point called the first focus of said reflector (12a, 12b), and said reflector (12a, 12b) having a shape such that after reflection, at least a part of the rays output from said source converges towards a point called the second focus (F) of said reflector, the reflectors (12a, 12b) of said two modules being open portions of ellipsoids or semi-ellipsoids extending above a plane of symmetry of said ellipsoid, characterised in that the light flux is directed, after reflection on said reflector (12a, 12b) towards the second focus (F) of the ellipsoid, and then to a convergent lens 3, in that each of said at least two modules is in a main beam position when the mirrors (4a, 4b) are inclined relative to the horizontal plan and are positioned entirely outside the light flux allowing all rays to pass towards the convergent lens (3) passing through a bottom part of the lens (3) and being directed upwards, and in that each of said at least two modules is in a dipped beam position when the mirrors (4a, 4b) are in a horizontal position and their longitudinal extent is sufficient to intercept all rays from the reflector (12a, 12b), all said rays being reflected upwards by the mirrors (4a, 4b) and being redirected by the mirror (4a, 4b) towards a top part of the convergent lens (3), the light rays being directed forwards with a downwards inflection, at the exit of said convergent lens (3).
2. Headlight according to claim 1, in which said two modules are positioned side by side, with their optical axes parallel, and in which their second focuses have the same abscissa on said optical axes.
3. Headlight according to claim 2, in which the reflecting surfaces are directed upwards relative to the plane of symmetry of said ellipsoid.
4. Headlight according to claim 3, in which the plane mirrors (4a, 4b) are placed longitudinally approximately in line with the second focus of their reflector (12a, 12b), said modules also comprising an inverter device for inverting its beam to redirect the light flux output from the second focus to a direction parallel to the optical axis.
5. Headlight according to the previous claim, in which the inverter device is, for at least one module, a lens (3) for which the longitudinal position of the focus is approximately in line with the second focus of the corresponding reflector.
6. Headlight according to any one of the previous claims, in which the rotation spindle (5) comprises a toothed sector (9) extending in a plane approximately perpendicular to the longitudinal direction of the rotation spindle.
7. Headlight according to claim 6, in which the rotation spindle is entrained by a single motor (6) engaging on said toothed sector (9).
8. Headlight according to claim 7, in which the motor (6) outputs a torque against a rotation return spring (7).
9. Headlight according to any one of the previous claims, in which the light source of at least one module is a light emitting diode (S).

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