Patent ID: 12203625

In the following description, elements that are identical, in structure or function, and that appear in more than one figure, have been designated by the same reference signs, unless otherwise indicated.

FIG.1depicts an optical module1for a luminous system of an automotive vehicle according to a first embodiment of the invention.

The optical module1comprises a single light-emitting diode2mounted on a printed circuit board3.

The optical module1comprises a primary optical system4, taking the form of a primary optical element4arranged downstream of the light-emitting diodes2. This primary optical element4will be described with reference toFIG.2, which shows a rear perspective view of this element4.

The primary optical element4comprises a plurality of optical members5and an exit optical member6to which these optical members5are linked. In the example described, each optical element is a primary optical member5taking the form of a primary light guide.

The primary light guides5have a common entrance face51, opposite which the LED2is placed, the light potentially emitted by this LED2thus entering each primary light guide5via this entrance face51.

Each primary light guide5is linked to the exit optical member6by a junction face52, which is located opposite the entrance face51and on an upstream wall61of the exit optical member6. The primary light guides5lie one above the next such that the junction faces52are spaced apart from one another.

Each primary light guide5thus extends from the common entrance face51to its junction face52. The primary light guides5therefore have a common envelope until they separate to each extend to their exit face in an envelope53of their own. This envelope53is a developable surface, such that each point of the outline of the entrance face51is linked, via the envelope53, to one point of the outline of the junction face52by a straight line. The light potentially emitted by the LED2located facing the entrance face51is thus coupled to each primary light guide5, and propagates via successive total internal reflections against the envelope53until it reaches the junction face52, via which it is decoupled from the primary light guide5and enters the exit optical member6. The junction face52thus forms an imaginary exit face of the primary light guide5.

The junction faces52of the primary light guides5may be separate from one another and from the entrance face51. The junction face52of a primary light guide5thus defines, by virtue of its outline, a pattern the shape of which is predetermined and specific to this light guide5. The envelope53of each primary light guide5thus makes it possible to exploit all the light emitted by the LED2through the entrance face51so as to obtain at the junction face52a pattern that is entirely delineated by appreciably sharp edges. Likewise, the envelope53makes it possible to obtain a uniform distribution of light inside this pattern, at the junction face52.

In the described example, the junction face52of the lower light guide has a triangular shape, while the junction faces52of the central and upper light guides are trapezoidal, the dimensions of the junction face52of the upper guide being smaller than those of the junction face52of the central guide.

As explained above, the primary light guides5are arranged such that two adjacent junction faces52are spaced apart. In other words, the primary light guides5thus make it possible to form a plurality of images, from the LED2, at the junction faces52, these images thus being vertically offset with respect to one another.

The primary optical element4is a one-piece part, the primary light guides5and the exit optical member6being manufactured from the same material, namely polycarbonate or PC. In the described example, the primary optical element4is a part produced in a single mold. In other words, the refractive index of the primary light guides5and of the exit optical member6is identical, and there is no dioptric interface at the junction faces52, such that the light entering the exit optical member6from the primary light guides5undergoes no deflection at the junction faces52.

The exit optical member6has a smooth, dome-shaped exit face62opposite the upstream face61. More precisely, this exit face62may be partially spherical, the exit optical member6thus having a truncated ball shape. The exit face62is in particular centered on the junction face52of the central light guide5. As a result, the light coming from the junction faces52undergoes substantially no deflection during its exit from the primary optical member4via this exit face62. The exit optical member6thus forms a carrier for mounting the primary light guides5, and it is possible to arrange elements for fastening the primary optical element4on this exit optical member6.

The optical module1comprises a projecting optical system7. In the example inFIG.1, the projecting optical system7is a projecting lens7having a focal plane71passing substantially through the junction surfaces52of the primary light guides5.

This projecting lens7is thus arranged to project onto the ground, in a near field, images of the junction faces52. Since the patterns formed on the junction faces52are entirely delineated by sharp edges, as a result of the primary light guides5, and the focal plane71passes through these junction faces52, these images projected onto the ground are therefore themselves entirely delineated by sharp edges, corresponding to the edges of these junction faces52, after inversion by the projecting lens7.

FIG.3illustrates a luminous system10of an automotive vehicle according to one example of embodiment of the invention.

The luminous system10comprises a front headlight11within which the optical module1ofFIG.1is arranged.

The luminous system10comprises a control unit (not shown) that receives instructions from a computer of the automotive vehicle with a view to performing light-emitting functions, and that controls the LED2of the optical module1depending on these instructions.

On receipt of an instruction to emit a sequential direction-indicator function, which is for example generated by the computer when the automotive vehicle wants to change lane, the control unit activates the LED2, the optical module1thus projecting onto the ground, in the vehicle's near field, images1a,1band1cof the junction faces52of the primary light guides5. It will thus be understood that the optical module1thus performs a direction-indicator function that may complement a direction-indicator function performed by a taillight of the vehicle. Since the images1a,1band1care projected onto the ground, in the vehicle's near field, they are thus able to be easily perceived by a road user driving on the right of the automotive vehicle. In particular, the images duplicated by each primary light guide5from the LED2are shown inFIG.3.

FIG.4depicts an optical module20of a luminous system of an automotive vehicle according to a second embodiment of the invention.

In this example, the optical module20comprises, as in the example ofFIG.1, a single LED2and a primary optical element arranged downstream of the light-emitting diodes2. However, unlikeFIG.1, the primary optical element comprises a single primary light guide5, the function of which is only to form, at the junction face52, an image from the LED2. This primary light guide5thus participates in forming the pattern that will be projected onto the ground, but not in duplication of this pattern.

To this end, the primary optical system4of the optical module20comprises a plurality of optical members8arranged between the primary optical element4and the projecting optical system7. Each optical member8is thus a secondary optical member, formed in the example ofFIG.4by a microlens8.

Each microlens8has a focal surface81located downstream of the junction face52, and an optical axis82, the optical axes82being parallel to one another but offset with respect to one another. Each microlens8is thus arranged to form an image of the junction face52in a given plane83located upstream of the primary optical element4, through which a focal surface of the projecting optical system7passes, the images of the junction face52being offset vertically with respect to one another.

Projection of these images of the junction face52, by the projecting optical system7, thus makes it possible to project onto the ground the same pattern in a duplicated manner.

The above description clearly explains how the invention achieves the objectives that were set for it, namely providing an optical module that is capable of projecting onto the ground a complex pattern from a single light source and that is efficient and simple, this optical module comprising optical members arranged to duplicate an image formed from the light source.

In any event, the invention is not limited to the embodiments specifically described in this document, and extends, in particular, to any equivalent means and to any technically operational combination of these means. It is in particular possible to envision using types of light source other than those described, and in particular light sources that are able to emit light of a color other than white or light of which the color can be controlled. It is also possible to envision shapes for the junction faces other than those described. It is also possible to envision types of optical members other than a light guide or microlens, and in particular collimators, lenses or microlenses, faceted reflectors or combinations of various types of primary optical members. It is also possible to envision light-emitting functions other than those described, and in particular other functions for indicating a change of motor-vehicle path, such as a reversing indicator or a lane-change indicator, driver-assistance functions or indeed inter-vehicle communication functions.