FR3028003B1 - MULTIMODULAR AUTOMOTIVE PROJECTOR WITH MOBILE MIRRORS ACTIONED BY A SINGLE ENGINE - Google Patents

Abstract

Multi-module projector for a motor vehicle, each module (11a, 11b) constituting said projector (11) comprising a light source (S) and a reflector (12a, 12b), said source being positioned at a point said first focus of said reflector (12a , 12b) and said reflector (12a, 12b) having a shape such that at least a portion of the rays coming from said source converge after reflection towards a point said second focus (F) of the reflector, each module further comprising a movable member of said reflector interception of the beam (4a, 4b) capable, according to its position, of intercepting or passing a portion of the light beam from said second focus, characterized in that the interception members (4a, 4b) of at least two modules are common or actuated by a common moving means (5).

Description

MULTIMODULAR AUTOMOTIVE PROJECTOR MOBILE MIRRORS POWERED BY A SINGLE ENGINE

The field of the present invention is that of automotive equipment and, more particularly, that of the 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 driving circumstances.

The reflectors generally take the form of a paraboloid or an ellipsoid of revolution, for which the light source is positioned at or at one of the foci 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. To reduce the size of the projector it has been imagined to reduce its vertical extension and keep only half of ellipsoid to form the reflector. In some embodiments, a mirror is then placed at the second focus, to return upward the light rays that end there.

It is known, moreover, to use a cutoff bar for 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 the dipped headlamps, called the code position, so as not to dazzle the drivers traveling in the opposite direction, or to that of the high beam, called the road position, in which it There is no occultation. This technology is commonly used with projectors having a high power light source, such as halogen lamp or xenon projectors, for which the loss of light power due to the interception of the flow by the bar is not really detrimental .

Furthermore, automotive headlight technology currently tends to use light sources consisting of LEDs (Light-Emitting Diode) for their reduced cost and longer life. On the other hand, the luminous power emitted by these devices remains for the moment still limited and it is necessary to use this one at best. It is therefore desirable to be able to do without the cutout 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 reflecting mirror of the beam between a position corresponding to the dipped beam, where it returns all the spokes to the top of the reversal lens, and a position corresponding to the main 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, either in order to obtain the desired light output, to give a particular shape to the beam or to modulate the distribution in its density of illumination.

This multiplicity of projectors, associated with distinct moving mirrors and mechanisms of movement of these mirrors makes the realization of LED projectors quite complex and it is desirable to simplify their implementation. The present invention, therefore, aims to overcome these disadvantages by providing, in particular for multiple projectors with semi-elliptical reflector, a simplified actuator. For this purpose, the subject of the invention is a multi-module searchlight for a motor vehicle, each module constituting said searchlight comprising at least one light source and at least one movable interception member of the beam able, according to its position, to intercept or passing a portion of the light beam from said source, characterized in that the interception members of at least two modules are common or actuated by a means of common movement.

This pooling reduces the number of parts needed to control the passage of high beam at low beam, and vice versa, and simplifies the realization of the projector.

In a particular embodiment each module comprises a reflector, said source of said module being positioned at a point, said first focus, said reflector and said reflector having a shape such that at least a portion of the rays from said source converge after reflection to a point, said second focus, of said reflector.

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

Preferably said two modules are positioned side by side, their optical axes being parallel, and their second foci have the same abscissa on said optical axes. This proximity simplifies, meanwhile, the realization of control means of the passage of high beam at low 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 intercepting member in said two modules is a reflective surface facing upwards. relative to the plane of symmetry of said ellipsoid. This configuration has the advantage of being more compact and more easily housed in a motor vehicle.

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

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

Advantageously said planar mirrors are rotatable about a same axis, oriented perpendicularly 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 provides a torque against a return spring in rotation. This device ensures the return of the headlamp in dipped beam in the event of a failure of the engine operating beam intercepting means.

In another embodiment, said reflecting surface is a complex surface capable of directly generating the shape of an automobile searchlight beam from at least a portion of the light beam issuing from said second focus.

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 objects, details, features and advantages thereof will appear more clearly in the following detailed explanatory description of an embodiment of the invention given as a purely illustrative and non-limiting example, with reference to the accompanying schematic drawings.

In these drawings: FIG. 1 is a schematic view of an elliptical motor vehicle headlight; FIG. 2 is a schematic view of a moving mirror semi-elliptical headlamp, in the high beam position, FIG. 3 is a view of the headlamp of FIG. 2, in the dipped beam position; FIG. 4 is a perspective view of a mutimodule headlamp according to the invention, with movable mirrors, in the position of high beams; FIG. 5 is a view of the headlamp of FIG. 4, in the dipped beam position, and FIG. 6 is a longitudinal sectional view of the headlight of FIG. 4.

Referring to FIG. 1, a motor vehicle headlamp 1 of the prior art is seen which is constituted by a reflector 2 having substantially the shape of an open portion of an ellipsoid, inside which is placed a S light source, and 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 side of the bottom of the reflector 2, and it emits on all the solid angle formed by the ellipsoid. All light rays emitted, after reflection on the reflector 2, towards the second focus F of the ellipsoid.

The lens 3 is positioned longitudinally on the x-x optical axis of the projector 1 in a position such that its focus is approximately at the second focus 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. This produces a light beam that illuminates the road in the distance, in a high beam position. It is then necessary to provide a cutoff mechanism (not shown) to eliminate, before crossing the lens, the lower portion of the beam and ensure the function of low beam.

Figures 2 and 3 show a semi-elliptical moving mirror headlamp respectively in high beam position and low beam. Unlike FIG. 1, the reflector 12 only includes the upper half of the ellipsoid portion of the previous case. As a result, the light source emits only on 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 LED light emitting diodes, which emit only on a solid angle of 2π steradians.

As before, the luminous flux is directed, after reflection on the reflector 12 towards the second focus F of the ellipsoid and then towards a convergent lens 3. Due to this emission on 2π steradians, the light beam is only directed towards half The shape of the lens and / or the position of its focus relative to the second focus F of the ellipsoid, is such that in the absence of any means of shunting the beam, it is redirected to forward.

But, as can be seen in Figures 2 and 3, a movable mirror 4 is positioned at the second focus F. Its reflective surface is directed upwardly so as to intercept the luminous flux from the reflector 12. This mirror 4 is movable about 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 position called retracted.

In Figure 2, the mirror 4 is inclined relative to the horizontal plane and is positioned entirely outside the luminous flux, thus passing all the rays in the direction of the lens 3. These traverse the lower part of the lens and are straightened upwards to illuminate the road for a great distance. We thus find ourselves in the position of high beams, without loss of the light power emitted by the source S.

On the other hand, in FIG. 3, the mirror 4 is in a horizontal position and its longitudinal span is sufficient to intercept all the rays coming from the reflector 12. All these rays are reflected upwards by the mirror 4 and are redirected by the mirror to the upper part of the lens 3. At the exit of the lens, the light rays are returned towards the front, 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 a shift of the focus thereof relative to the second focus of the ellipsoid. We then find ourselves in the position of the low beam, this time again without loss of the light power emitted by the source S.

FIGS. 4 and 5 show, respectively in high beam and low beam configuration, a headlamp 11 which consists of two semi-elliptical LED modules 11a and 11b, juxtaposed next to one another, whose axes of symmetry are parallel. By module of a projector is meant a light system in which all or some of the rays coming from a light source are reflected by a reflective surface towards a focal point called a focus.

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 movable mirror, respectively 4a and 4b, which can move in rotation around a horizontal axis, transverse to the direction of the optical axis of the modules. As is explained for a single module with reference to FIGS. 2 and 3, the light sources are positioned at the first focus of each of the reflectors, and the moving mirrors are positioned at the second focal point of these same modules. Thus the rotation of each of the mirrors allows the realization of a beam either in the configuration of high beam (lowered mirror), or in the configuration of low beam (mirror up). The provision of a multiplicity of modules makes it possible, for example, to provide a higher luminous power, to obtain a larger beam width or even to generate a higher light density in a part of the beam, particularly in its center. It is important, however, that these two (or more) modules operate in symbiosis and simultaneously move from the position of high beam to low beam, and vice versa.

To ensure this simultaneity, the invention recommends, for example, to mount the movable mirrors on a common axis 5 which is oriented perpendicular to the optical axis. This axis is rotated by means of a motor 6 and returned to a rest position, corresponding to the position of the dipped beam, by a return means, such as for example a torsion spring 7. Tel illustrated in the figures, the return spring 7 is mounted on the axis 5, and is supported on the one hand on the structure of the projector 11 and, on the other hand, on a stop 51 carried by the axis 5. As for the motor 6, it is positioned at one end of the axis 5, for example under one of the two modules as shown in FIGS. 4 or 5, and is fixed on the structure of the corresponding projector module 11a.

FIG. 6 shows, in side sectional view, the sectional plane lying in the vertical plane of symmetry of the ellipsoid of the first module 11a, the detail of the various devices 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 x-x, downstream of the second focus F of the reflector 12a. The movable mirror 4a is shown in its retracted position, corresponding to the position of the main beam, and it has free space above it, to be able to position itself along the optical axis and thus take the position corresponding to the low beam. The axis of rotation 5, carrying the mirror 4a, rotates in bearings carried by the structure of the projector 11a and extends horizontally under the optical axis. It has generally a cylindrical shape of revolution with, however, on each side of each of the mirrors 4a and 4b that it carries, faceted shapes on which are wedged support pieces 52 of said mirrors. These faceted shapes allow rotation of the mirrors when the axis 5 is itself rotated 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 and which extends in a vertical plane, downwards. This toothed sector cooperates with the teeth (not visible) of a drive shaft leaving 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 clockwise rotates the axis 5 counterclockwise by compressing the return spring 7. It brings the mirror 4a in the retracted position (as shown in Figure 6), which corresponds to the high beam. Conversely a rotation of the motor in the counterclockwise direction releases the pressure on the spring 7 and allows the mirror to return to the horizontal position, which corresponds to the dipped beam.

As illustrated in FIGS. 4 or 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. the prior art each projector module has its own actuator motor of its mirror, the invention thus allows with a minimum of means to achieve the passage of all modules from one position (code or route) to the other position and make this flip-flop simultaneously to all the modules of the projector 11. The axis 5 has been represented in the form of a cylinder of revolution, with modules positioned side by side in the alignment of this axis but the invention can just as well be realized with modules that are offset longitudinally or vertically with respect to each other, provided that there is a unique means that is able to operate 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 gives the desired shape to the beam. It could equally well be achieved by a single beam reversal member, such as a mirror having a complex shape that returns the light beam forward giving it the desired shape. The transition from the high beam configuration to the low beam is, in this case, provided by a displacement of the complex shape mirror, which is thus movable as is the plane mirror of the configuration described.

Likewise, the beam intercepting means for passing high beam at low beam has been described in the form of a mirror movable in rotation about an axis transverse to the optical axis. It could equally well be realized in the form of a mobile cover which would be mobile in vertical translation or by any other moving means, provided that it is able to take several positions in which it intercepts a part of the beam and think about it, let him pass.

Finally, the projector described has the shape of a half-ellipsoid, but the principle of a common means for operating the beam intercepting device 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 projector which comprises a reflector, whether it is an ellipsoid or a semi-ellipsoid. It can equally well be implemented on a projector that does not have a reflector, the light emitted by the light source, such as for example that LEDs, then being directed directly on the mobile interception means which passes the beam of low beam at low beam and vice versa at low beam.

Claims (12)

1. Multi-module projector for a motor vehicle, each module (11a, 11b) constituting said projector (11) comprising at least one light source (S) and at least one movable beam intercepting element (4a, 4b) adapted, according to its position, to intercept or let part of the light beam coming from said source, the interception members (4a, 4b) of at least two modules being actuated by a means of common movement, characterized in that the reflecting surfaces of the two modules are planar mirrors (4a, 4b), said planar mirrors (4a, 4b) being mounted on a common axis (5) and being rotatable about said common axis (5), oriented perpendicular to a optical axis. 2. Projector according to claim 1, wherein each module (11a, 11b) comprises a reflector (12a, 12b), the source (S) of said module being positioned at a point, said first focus, said reflector (12a, 12b). and said reflector (12a, 12b) having a shape such that at least a portion of the rays from said source converge after reflection to a point, said second focus (F), of said reflector. 3. Projector according to claim 2, wherein the reflectors (12a, 12b) of said two modules are open portions of ellipsoids or half-ellipsoids extending above a plane of symmetry of said ellipsoid. 4. Projector according to one of claims 2 or 3 wherein said two modules are positioned side by side, their optical axes being parallel and wherein their second homes have the same abscissa on said optical axes. 5. Projector according to claim 4, with semi-elliptical reflectors, wherein the beam intercepting member (s) in said two modules have a reflective surface facing upwards with respect to the plane of symmetry of said ellipsoid. 6. Projector according to claim 5, wherein the reflecting surfaces of the two modules are plane mirrors (4a, 4b) placed, longitudinally, substantially at the second focus of their reflector (12a, 12b), said modules further comprising a member for turning its beam to redirect the light flux from the second focus in a direction parallel to the optical axis. 7. Projector according to one of the preceding claims, wherein the turning member is, for at least one module, a lens (3) whose focus is positioned longitudinally substantially at said second focal point of the corresponding reflector. 8. Projector according to one of the preceding claims, wherein the axis of rotation (5) comprises a toothed sector (9) extending in a plane substantially perpendicular to the longitudinal direction of the axis of rotation. 9. Headlight according to claim 8, wherein the axis of rotation is driven by a single motor (6) meshing on said toothed sector (9). 10. Headlight according to claim 9, wherein the motor (6) provides a torque against a return spring rotation (7). 11. Projector according to claim 10, wherein said reflective surface is a complex surface capable of directly generating the shape of a motor vehicle beam from at least a portion of the light beam from said second focus. 12. Projector according to one of the preceding claims, wherein the light source of at least one module is a light emitting diode (S).