EP4264123B1 - Dual-function lighting device with rotating lens - Google Patents

Description

Technical field

The invention relates to the field of lighting and light signaling, in particular for motor vehicles.

Previous technique

It is generally known to produce a cut-off lighting beam using one or more folding light modules. Such a light module conventionally comprises a collector with a reflective surface of revolution with an elliptical profile, in the shape of a cap in a half-space delimited by a horizontal plane. An essentially point light source, of the electroluminescent diode type, is located at a first focus of the reflective surface and illuminates in the half-space in the direction of said surface. The rays are thus reflected in a convergent manner towards a second focus of the reflective surface. Another generally flat reflective surface, with a cut-off edge at the second focus, ensures an upward reflection of the rays which do not pass precisely through the second focus, these rays then being refracted by a thick lens towards the bottom of the lighting beam. This reflective surface is commonly referred to as a "folder" in that it "folds" towards the top of the projection lens the rays which would otherwise form an upper part of the lighting beam. Such a light module has the disadvantage of requiring high precision in the positioning of the folder and the cutting edge. Also, the projection lens must be a thick lens due to its short focal length, which increases its weight and complicates its production, such as shrinkage defects. In addition, the collector has a certain height and, therefore, a certain height requirement.

The published patent document WO 2020/025171 A1 discloses a light module in particular for a motor vehicle, comprising a collector with a reflective surface collecting and reflecting the light rays emitted by a light source into a light beam, similar to a folding light module. The light module also comprises an optical projection system, such as a lens, specifically configured to project the light beam in question by forming an image of the reflective surface of the collector. For this purpose, the optical projection system has a focus located on the reflective surface, for example at a rear edge thereof, so as to correctly image said edge and form a cut-off clear in the projected light beam. This type of light module has the advantages of compactness, particularly in height, and simplicity of production. They can be combined to form different light beams which add up.

It is generally interesting to group together as many lighting functions as possible in a single lighting device, particularly for reasons of style. In this logic, improvements remain to be made.

Disclosure of the invention

The invention aims to overcome at least one of the drawbacks of the aforementioned state of the art. More particularly, the invention aims to propose a lighting device which integrates a maximum of lighting functions.

The invention relates to a light device for a motor vehicle, comprising one or more light sources capable of emitting light rays; one or more collectors each with a reflective surface configured to collect and reflect the light rays emitted by the one or more light sources, called reflected light rays, into a reflected light beam along an optical axis; an optical system comprising a projection lens performing a first optical function performing the projection of at least the majority of the reflected light beam into a projected light beam by imaging a portion of the or each reflective surface located, along a general direction of propagation of the light beam, behind the or each corresponding light source; remarkable in that the optical system comprises an additional portion distinct from the projection lens and performing a second optical function performing a diffusion of at least the majority of the reflected light beam into a diffused light beam, said optical system being rotatable about an axis of rotation between a first position where the first function is active and a second position where the second function is active.

Described below are advantageous but non-limiting embodiments of the invention, one or more of these embodiments being able to be combined with each other.

The collector can be a concave reflector.

At least some of the reflected rays have angles of inclination relative to the optical axis that are less than or equal to 10°. This allows for so-called Gaussian conditions, thus allowing stigmatism.

According to an advantageous embodiment of the invention, the additional part is formed by one or more diffusing screens, the or each diffusing screen being crossed by at least the majority of the reflected light beam when the optical system is in the second position, the at least majority of the reflected light beam being diffused after having crossed said screen to form the diffused light beam.

According to an advantageous embodiment of the invention, the projection lens has a focal zone located on the reflecting surface of the or each of the corresponding collectors, at a rear edge of said reflecting surface. This simply makes it possible to image the part of the part of the reflecting surface located at the rear of the light source. Advantageously, the focal zone is located at a rear edge of said reflecting surface. Generally speaking, this focal zone can be a focal point, also called a focus, or can be a focal line, also called a line of focuses. According to an advantageous embodiment of the invention, the optical system comprises an optical part comprising the projection lens and the additional part, the lighting device comprising a mechanism for rotating said optical part around the axis of rotation. Advantageously, said optical part is a transparent part.

According to an advantageous embodiment of the invention, the optical part comprises a first input face and a first output face associated with the first input face, corresponding to the projection lens, and a second input face and a second output face associated with the second input face, corresponding to the additional part, the first and second input faces and/or the first and second output faces being angularly offset around the axis of rotation by an angle of between 60° and 120°.

Advantageously, the second output face has an average height, perpendicular to the axis of rotation, greater than an average height, perpendicular to the axis of rotation, of the first output face.

Advantageously, the first output face has an average height, perpendicular to the axis of rotation, less than 10 mm.

According to an advantageous embodiment of the invention, in the first position of the optical system, the first input face is positioned facing the one or more collectors, and in the second position, the second input face is positioned facing the one or more collectors.

According to an advantageous embodiment of the invention, the axis of rotation of the optical system is transverse to the optical axis and horizontal when the lighting device is in the operational position.

Advantageously, the optical part is elongated along the axis of rotation.

Advantageously, the rotation of the optical system between the first and second functions has an angular amplitude of between 60° and 120°.

According to an advantageous embodiment of the invention, the light beam projected in the first position of the optical system is a lighting beam and the light beam diffused in the second position of the optical system is a signaling beam or a light signature. Here, a light signature is a light beam having an aesthetic light function which would make it possible to identify the model and/or make of the vehicle in all circumstances.

According to an advantageous embodiment of the invention, the light device comprises several light sources and several collectors with several reflecting surfaces so as to form several added reflected light beams, and in which the optical system is rotatable between the first position where the projection lens receives at least the majority of said reflected light beams and a second position where the additional part receives at least the majority of said reflected light beams.

Advantageously, each of the at least one light source, the at least one collector and the at least one reflective surface is multiple so as to selectively form several light beams that add together. For example, the multiple collectors, reflective surfaces and light sources are arranged side by side. Advantageously, the first function of the optical system comprises a focal line passing through the reflective surfaces, more advantageously through the rear edges of said reflective surfaces, or between said reflective surfaces and the corresponding light sources.

According to an advantageous embodiment of the invention, in the second position of the optical system, the second function of said optical system forms a light beam from light rays emitted by one or more auxiliary light sources.

The measures of the invention are interesting in that they make it possible to integrate at least one additional light function into a lighting device, without actually increasing the necessary volume. The light sources present in the device for the lighting function(s) can be used for the additional function.

Brief description of the drawings

• [ fig.1 ] is a perspective view of a light device according to the invention, said device comprising an optical system;
• [ fig.2 ] is a schematic representation, in longitudinal section, of the lighting device of the [ fig.1 ] when the optical system is in a first position;
• [ fig.3 ] is a schematic representation, in longitudinal section, of the lighting device of the [ fig.1 ] when the optical system is in a second position.

Detailed description

THE Figures 1 to 3 illustrate an exemplary embodiment of the invention.

More specifically, the [ fig.1 ] is a perspective view of a lighting device according to the invention.

The lighting device 2 is, here, a selectively lighting and signaling device, as will be detailed below. The lighting device 2 comprises a housing 4 itself being able to consist of a series of components or housing portions, assembled to each other. As can be seen, the housing 4 comprises several optical cavities with light sources 6.1, 6.2, 6.3 and reflective surfaces 8.1, 8.2 and 8.3. Each of the reflective surfaces 8.1, 8.2 and 8.3, associated with a light source, forms a unit capable of producing a light beam.

The lighting device also comprises an optical system 10 capable of receiving and shaping the light beams in question. The optical system 10 comprises an optical part 12 with a dual function, namely a first optical projection function and a second optical light diffusion function. For this purpose, the optical part 12 is mounted to rotate about an axis of rotation 14 so as to activate, selectively, one or the other of the first and second functions. The lighting device 2 comprises a mechanism 16 for rotating said optical part 12 about the axis of rotation 14. This mechanism may comprise an electric motor coupled to an angle return mechanism itself coupled to the optical part.

In the position of the optical part 12 illustrated in [ fig.1 ], the second light diffusion function is activated, meaning that the light beams produced by the light sources and associated reflective surfaces will be diffused in order to provide a signaling function.

THE Figures 2 and 3 illustrate schematically and in longitudinal section the lighting device of the [ fig.1 ] in the first and second functions, respectively. More specifically, these figures illustrate a single light source and a single reflective surface associated with the light source, it being understood that they apply to each of the light sources and associated reflective surfaces.

There [ fig.2 ] illustrates the light device 2 when the optical device is in the first position where the first optical function of projecting the light beam is active.

It can be observed that the optical part 12 comprises a first portion 12.1 corresponding to the first function and a second portion 12.2 corresponding to the second function. The first portion 12.1 of the optical part 12 is active by being arranged facing the light rays emitted by the light source 6 and reflected by the reflecting surface 8, while the second portion 12.2 is inactive by being arranged at a distance from the rays in question. In this case, these two portions each have a generally elongated cross section, these two cross sections forming an elbow with an angle close to the order of 90°, advantageously between 70° and 100°. These cross sections in principle have different geometries given their different optical functions.

The first portion 12.1 of the optical part 12, ensuring the first function forms a projection lens with an input face 12.1.1 and an input face 12.1.2. This lens may in particular be of the plano-convex or biconvex type. The second portion 12.2 of the optical part 12, ensuring the second function also comprises an input face 12.2 1 and an output face 12.2.2.

Described otherwise, according to the invention and as in the illustrated example, the first portion 12.1 is formed by a projection lens while the second portion 12.2 is here formed by an additional part distinct from the projection lens.

Here, as generally according to the invention, the light source 6 is advantageously of the semiconductor type, such as in particular a light-emitting diode. The light source 6 emits light rays in a half-space delimited by the main plane of said source, according to the example shown, in a main direction perpendicular to said plane and to the optical axis 18. According to the invention, the main emission direction may be between 65° and 115° relative to the optical axis 18.

A collector 20 forms a shell-shaped or cap-shaped support, on the inner face of which the reflecting surface 8 is applied. The reflecting surface 8 advantageously has an elliptical or parabolic profile. It is advantageously a surface of revolution about an axis parallel to the optical axis. Alternatively, it may be a free-form surface or a swept surface or an asymmetrical surface. It may also comprise several sectors. The shell-shaped or cap-shaped collector 20 is advantageously made of materials having good heat resistance, for example glass or synthetic polymers such as polycarbonate PC or polyetherimide PEI. The expression "parabolic type" generally applies to reflectors whose surface has a single focus, i.e. a zone of convergence of the light rays such that the light rays emitted by a light source placed at this convergence zone are projected over a great distance after reflection on the surface. Projected at a great distance means that these light rays do not converge towards an area located at least 10 times the dimensions of the reflector. In other words, the reflected rays do not converge towards a convergence zone or, if they converge, this convergence zone is located at a distance greater than or equal to 10 times the dimensions of the reflector. A parabolic surface may therefore have parabolic portions or not. A reflector with such a surface is generally used alone to create a light beam. Alternatively, it can be used as a projection surface associated with an elliptical reflector. In this case, the light source of the parabolic reflector is the convergence zone of the rays reflected by the elliptical reflector.

The light source 6 is arranged at a focus of the reflecting surface 8 of such that its rays are collected and reflected along the optical axis, said rays, called reflected rays, forming a reflected light beam. At least part of these reflected rays have angles of inclination a in a vertical plane relative to said axis which are less than or equal to 25°, preferably less than or equal to 10°, so as to be in the so-called Gaussian conditions, making it possible to obtain a stigmatism, that is to say a sharpness of the projected image. These are advantageously the rays reflected by the rear part of the reflecting surface 8.

The first portion 12.1 of the optical part 12, forming the projection lens, has a focus 12.1.3 which is located along the optical axis 18, at the level of the light source 6 or behind said source. In this case, the focus 12.1.3 is located on the reflecting surface 8, at a rear edge, here also lower edge, thereof. It should be noted that it is also possible for this focus to be located at the rear or at the front of the reflecting surface 8, preferably nearby, in particular less than 10 mm, preferably less than 5 mm.

The reflecting surface 8, if it is of the elliptical type, has a second focus located at the front of the lens 12.1 and at a distance from the optical axis 18. It should be noted that it is also possible for this focus to be located at the rear of the lens and/or on the optical axis, preferably close to the lens, so as to reduce the width of the beam at the level of the entrance face of the lens.

Here, the first portion 12.1 described is configured to project at least the majority of the reflected light beam into a projected light beam performing a lighting light function.

There [ fig.3 ] illustrates the light device 2 when the optical device is in the second position where the second optical function of diffusing the light beam is active.

Compared to the [ fig.2 ], it can be observed that the optical part has undergone a rotation about its rotation axis 14 of the order of 90°, in this case in the anti-clockwise direction, so as to make the first portion 12.1 inactive and the second portion 12.2 active. In this case, the input face 12.2.1 of the second portion 12.2 intersects with the optical axis 18 and is located opposite the reflecting surface 8 and the light source 6, so as to collect the light beam produced by the latter, also called the reflected light beam. At least one of the input 12.2.1 and output 12.2.2 faces may have a rough or grained surface so as to provide a light diffusion function. For example, the second portion 12.2 is configured to project at least the majority of the reflected light beam into a diffusing light beam which here performs a light signaling function.

In this case, the input face 12.2.1 of the second portion 12.2 of the optical part 12 is at a distance from the reflecting surface 8 that is potentially different from that of the input face 12.1.1 of the first portion 12.1 (when the latter is in the active position). This does not pose a problem in that the function of the second function of the optical system is not to image the reflecting surface 8 illuminated by the light source 6 like the first function. In this case, the second function consists of diffusing the light in order to provide a signaling function. It should be noted that the input face 12.2.1 of the second portion 12.2 is higher (in a direction perpendicular to the optical axis when the function is active) than the input face 12.1.1 of the first portion 12.1, allowing it to collect more rays reflected by the reflecting surface 8.

It should be noted that it is also possible to provide one or more auxiliary light sources for the second function, i.e. inactive for the first function.

The second function described above may be, for example, a signaling function that is not necessary when the motor vehicle is moving. In particular, it may be a function such as a position light or lantern, or a light signature, activated when the vehicle is parked or stopped for a long time.

With reference to the [ fig.1 ], the optical system 10 may be common to several collectors, reflecting surfaces and associated light sources, arranged side by side. In this case, the first function may then have not a point focus but a focus line passing through the rear parts of the reflecting surfaces in question. The focus line in question may not be rectilinear, in this case slightly curved.

Claims (10)

1. A lighting device (2) for a motor vehicle, comprising:

   - one or a plurality of light sources (6) which can emit light rays;

   - one or a plurality of collectors (20), with a reflective surface (8), the or each reflective surface being configured to collect and reflect the light rays emitted by the one or more light sources (6), known as reflected light rays, into a reflected light beam along an optical axis (18);

   - an optical system (10) comprising a projection lens (12.1) which provides a first optical function providing the projection of at least most of the reflected light beam into a projected light beam by imaging part of the or each reflective surface (8) situated, in a general direction of propagation of the light beam, to the rear of the or each corresponding light source (6);

   characterized in that the optical system (10) comprises an additional part (12.2) which is distinct from the projection lens, and providing a second optical function providing diffusion of at least most of the light beam reflected into a diffused light beam, said optical system being rotatable around an axis of rotation (14), between a first position in which the first function is active, and a second position in which the second function is active.
2. The lighting device (2) as claimed in claim 1, wherein the additional part (12.2) is formed by one or a plurality of diffusing screens, the or each diffusing screen having passing through it at least most of the reflected light beam, when the optical system (10) is in the second position, the at least most of the reflected light beam being diffused after having passed through said screen in order to form the diffused light beam.
3. The lighting device (2) as claimed in one of claims 1 and 2, wherein the projection lens (12.1) has a focal area (12.1.3) situated on the reflective surface of the or each of the corresponding collectors, at a rear edge of said reflective surface.
4. The lighting device (2) as claimed in one of claims 1 to 3, wherein the optical system (10) comprises an optical part (12) comprising the projection lens and the additional part, the lighting device (2) comprising a mechanism (16) for rotation of said optical part (12) around the axis of rotation (14).
5. The lighting device (2) as claimed in one of the preceding claims, wherein the optical part (12) comprises a first input face (12.1.1) and a first output face (12.1.2) associated with the first input face (12.1.1), corresponding to the projection lens (12.1), and a second input face (12.2.1) and a second output face (12.2.2) associated with the second input face (12.2.1), corresponding to the additional part (12.2), and wherein the first and second input faces (12.1.1, 12.2.1) and/or the first and second output faces (12.1.2, 12.2.2) are offset angularly around the axis of rotation (14) by an angle of between 60° and 120°.
6. The lighting device (2) as claimed in the preceding claim, wherein, in the first position of the optical system (10), the first input face (12.1.1) is positioned facing the collector(s) (20), and in the second position of the optical system (10), the second input face (12.2.1) is positioned facing the collector(s) (20).
7. The lighting device (2) as claimed in one of the preceding claims, wherein the axis of rotation (14) of the optical system (10) is transverse to the optical axis (18), and horizontal when the lighting device (2) is in the operational position.
8. The lighting device (2) as claimed in one of the preceding claims, wherein the projected light beam in the first position of the optical system (10) is a lighting beam, and the diffused light beam in the second position of the optical system (10) is a signaling beam or a lighting signature.
9. The lighting device (2) as claimed in one of the preceding claims, wherein the lighting device comprises a plurality of light sources (6) and a plurality of collectors (20) with a plurality of reflective surfaces (8), such as to form a plurality of reflected light beams which are added together, and wherein the optical system (10) can rotate between the first position, in which the projection lens (12.1) receives at least most of said reflected light beams, and a second position, where the additional part (12.2) receives at least most of said reflected light beams.
10. The lighting device (2) as claimed in one of the preceding claims, wherein, in the second position of the optical system (10), the second function of said optical system forms a light beam from light rays emitted by one or a plurality of auxiliary light sources.

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