FR3100866A1 - Vehicle headlight - Google Patents

Abstract

Headlight (1) for a vehicle (2), configured to generate a lighting zone (3) in front of the vehicle (2) and comprising: - a first source (10) of fixed matrix lighting configured to emit a light beam of road (11), - a second movable light source (20) configured to emit a passing light beam (12), and - a correction mechanism (30) configured to maintain a constant vertical inclination of the passing light beam ( 12) relative to a horizontal reference line (H), when the vehicle is rolling, characterized in that it further comprises a dioptric lens (40), having at least one plane incidence face, configured to eliminate at least one shadow zone (5) which may occur, at said lighting zone (3), between the driving light beam (11) and the passing light beam (12). Figure to be published with the abstract: Fig. 4

Description

vehicle projector

The present invention generally relates to the field of vehicle headlamps, in particular of motor vehicles, and in particular the field of front headlamps comprising two light sources, one generating a main beam and the other a dipped beam. .

Vehicle headlights or headlights generally include adjustment means arranged to ensure adjustment of the azimuth and elevation of the optical module. The site corresponds to the attitude or the inclination in the vertical plane of the optical module. Such adjustment means are described for example in the documents FR3032513A and FR3026688A which, in particular, refer to headlamps without glass. In such a headlamp, the front face of the optical module is delimited by an external lens, which has the advantage of reducing the absorption of part of the light (up to 10%) by the material which would constitute the lens. .

The adjustment of the site of the projection beam can depend for example on the load transported at the rear of the vehicle, a load which causes the front of the vehicle to lift and which typically must be compensated by such an adjustment. More sophisticated systems also allow, when driving the vehicle, dynamic adjustment so that the beam is never dazzling for oncoming road users. These systems are generally configured to keep a constant inclination of the beam in the vertical plane with respect to a horizontal reference line. The document FR3015003A describes a motor vehicle headlamp devoid of glass and comprising two lighting modules equipped with site adjustment.

The document FR2745061A describes a motor vehicle headlamp allowing in a simple and economical way to generate two light beams, one for a crossing function and the other for a road function, from a single source and from a mirror.

More recently, there are still matrix lighting beams, consisting of a matrix of light-emitting diodes (LEDs) arranged on a flat support, such as a printed circuit for example. These LEDs can be distributed in vertical bands (sometimes called "matrix beam" in English) where each band has an independent operation of the other bands. As a variant, these LEDs can be divided into pixels (“pixel light” in English) where each LED can be switched on or off independently.

These matrix lights are designated as being adaptive lights, known by the acronym ADB for "Adaptive Driving Beam" in English, because they make it possible to optimize the lighting of the road without dazzling the vehicle or the user coming reverse. Indeed, in these types of lighting intended mainly for the main beam, mutually independent lighting zones have been created within the same beam, so as to be able to activate or extinguish these zones as required. The management of the activation of the LEDs, associated with these lighting sectors or zones, can typically be controlled by an electronic unit coupled to a means of detecting the location of a target not to be dazzled within the light beam of road. Such detection means can be an infrared camera for example.

An ADB ("matrix" or "pixel") type lighting module makes the mechanical movements necessary for on-site adjustment technically complex. For this reason, headlamps fitted with an ABD module, for the main beam, and a standard module, for the dipped beam, only offer site adjustments on the standard module associated with the dipped beam. The module ABD therefore remains a fixed module, namely immobile.

The main drawback of these headlamps lies in the fact that if only one of the two modules can be adjusted in elevation, a shadow zone located between the main and dipped beams can sometimes occur and become annoying for the driver.

Consequently, there is an interest in finding an efficient and more adequate solution which, while remaining economical, makes it possible at least in part to resolve the aforementioned drawback.

For this purpose, the present invention relates in a first aspect to a vehicle headlamp, configured to generate a lighting zone in front of the vehicle and comprising:
- a first fixed matrix lighting source configured to emit a road light beam,
- a second mobile lighting source configured to emit a crossing light beam, and
- A correction mechanism configured to maintain a constant vertical inclination of the passing light beam with respect to a horizontal reference line, when the vehicle is moving.

According to the invention, the vehicle headlamp further comprises a dioptric lens, having at least one plane incidence face, configured to suppress at least one shadow zone that may occur, at the level of said lighting zone, between the main beam and dipped beam.

Advantageously, the headlamp of the present invention makes it possible to improve the comfort and safety of the driver of the vehicle when driving at night while offering a simple and economical solution to headlamps equipped with a two-beam architecture, one of which constitutes a source of light. matrix lighting. Indeed, thanks to the invention, the shadow zone or at least a part of the latter which may occur between the main and dipped beams, in particular when the latter is corrected in elevation, can be eliminated using 'a simple compensating optical means, while keeping the ADB module fixed.

In one embodiment, the diopter lens is movably mounted, in front of the first light source, between:
- at least one working position, making it possible to refract incident rays of the road light beam, and
- A rest position, without refraction effect on said incident rays;
and in that said dioptric lens comprises an emerging face from which emerge said incident rays in a refracted beam intended to project, at the level of the illumination zone, the road light beam adjacent or partially superimposed on the light beam of crossing.

In one embodiment, the diopter lens is mounted to move along a translation axis, and said emergence face constitutes an at least partially curved diopter, having a variable deflection power of the refracted beam which depends on the position of the diopter lens on said translation axis.

In one embodiment, said diopter also comprises a portion parallel to the face of incidence of the diopter lens, and said parallel portion constitutes the rest position of the diopter lens.

Preferably, the first lighting source consists of a plurality of light-emitting diodes arranged in a matrix fashion on a flat support and in that the incident face of the dioptric lens is parallel to said flat support.

In one embodiment, primary optics, consisting of a matrix of converging lenses, is arranged in front of said flat support and in that the flat incident face of the dioptric lens is located in a focal plane of said converging lenses.

In a preferred embodiment, the dioptric lens constitutes a deflecting member that can be activated and/or deactivated by a control signal from a control member configured to prevent or detect said shadow zone.

Preferably, the control member is a control member of an angle of inclination of the correction mechanism and this member is configured to generate and transmit, to the deflector member, said control signal when said angle of inclination reaches a threshold value.

In another embodiment, said control signal is configured to be subordinated to a matrix lighting management member of the first source, in order to be able to deactivate the deflecting member in the presence of a target located, at the level of the lighting zone, between the main light beam and the dipped light beam.

In a second aspect, the invention also relates to a vehicle, in particular a motor vehicle, comprising a headlamp according to any one of the embodiments of this headlamp or according to any possible combination of these embodiments.

is a schematic illustration of a lighting zone obtained by a first matrix lighting source of a first type and by a second standard lighting source;

is a schematic illustration, similar to that of FIG. 1, in which the first matrix illumination source is of a second type;

is a schematic illustration of the shadow zone that may occur between the beams of the aforementioned first and second lighting sources;

is a schematic illustration of the main elements of a headlamp according to the present invention;

is a schematic illustration, in a side view, of the first fixed matrix lighting source according to the invention; And

is an illustration of a preferred embodiment of the invention in a view similar to that of FIG. 5.

With reference to FIG. 1, the latter schematically represents a lighting zone 3 obtained by a first source 10 of matrix lighting and by a second source 20 of standard lighting. More precisely, the first source 10 produces a first lighting zone 31 and the second source 20 produces a second lighting zone 32. In the present case, these first and second lighting zones 31, 32 can be qualified as partial lighting zones, because they only form the lighting zone 3 when they are considered together.

An orthonormal reference formed by a horizontal axis H and a vertical axis V is illustrated superimposed on the lighting zone 3. The lighting of the first source 10 is of the matrix type and is formed of a plurality of bands lighting uprights 10' aligned adjacent to each other. Each vertical lighting strip 10' can typically be obtained from a column of light-emitting diodes (LEDs) constituting a portion of the first source 10. The advantage of this type of lighting lies in the fact that each 10' vertical lighting strip can be turned on or off independently.

By coupling the first lighting source 10 to a matrix lighting management unit 60 (FIG. 4), it becomes possible to control each of the vertical lighting strips 10' according to the needs of the moment. In particular, the combination of an infrared camera or any other on-board detection system (in night conditions) of a target liable to be dazzled, can then be able to select the vertical strips of lighting 10' which , for example, must be turned off so as not to disturb the target, in particular when it is a vehicle or a pedestrian coming in the wrong direction. This first source 10 of matrix lighting can be described as adaptive since it is capable of dynamically generating an adaptive or modulating beam. For this reason, such a type of lighting is generally known by the acronym ADB ("Adaptive Driving Beam").

If the first source 10 of matrix lighting is typically used as a main beam, the second, more modest lighting source is generally dedicated to the dipped beam. This second source 20 is usually not of the matrix type but is more conventionally made up of a bulb, for example a halogen or xenon bulb.

To improve the driver's night vision and avoid dazzling oncoming road users, an additional measure is applied to the headlamps of recent vehicles. This measure consists in dynamically correcting the elevation lighting of the second source 20 dedicated to dipped headlights. For the record, such an adjustment consists in varying the average angle of projection of the crossing light beam in the vertical plane, so as to correct the height of the partial illumination zone 32 with respect to a horizontal reference line or d axis H. The correction takes place dynamically, ie at all times while the vehicle is moving. Typically, the upper radius of the driving light beam will usually be set so that it is at an inclination of 0.57º below the horizontal reference line H. This inclination corresponds to an angle having a slope of 1% facing down from the source.

Fig. 2 represents a variant of the illustration given in FIG. 1. Indeed, in FIG. 2, the matrix lighting of the first source 10 is "pixel" type lighting in which the vertical lighting bands 10' have been further subdivided by horizontal lines so as to obtain a multitude of pixels 10". Each pixel 10" can consist of one LED diode or an array of a plurality of LED diodes. The advantage of such a light source lies in the fact that the granulometry of the light offers finer partitioning than that provided by the first source 10 shown in FIG. 1.

Fig. 3 schematically represents the main problem presented by headlamps provided with light sources 10, 20, such as those illustrated indifferently in FIGS. 1 or 2. Because one of the two lighting sources, in particular the second source 20 generating the passing light beam, is dynamically corrected in elevation, a shadow zone 5 can sometimes appear in the zone of lighting 3, between the partial lighting zones 31, 32. This shadow zone 5 occurs as a function of the inclination or attitude of the vehicle relative to the profile of the terrain and can constitute a nuisance for the driver of the vehicle in particular. The object of the present invention aims in particular to obviate, at least in part, this drawback.

It should be noted that due to the complexity of the optical module necessary for the first source 10 of matrix lighting, this lighting is preferably made fixed or immobile. Consequently, the first source 10 generating the road light beam must be considered as not being able to be tilted in elevation, unlike the second source 20 generating the passing light beam.

As shown very schematically in FIG. 4, to at least partially solve the aforementioned problem, the object of the present invention proposes in its first aspect a headlamp 1, of vehicle 2, configured to generate a lighting zone 3 in front of vehicle 2. This headlamp or vehicle headlight may be provided with protective glass or preferably be free of such glass.

The projector 1 of the present invention comprises:
- a first source 10 of fixed matrix lighting configured to emit a main beam of light 11,
- a second mobile light source 20 configured to emit a passing light beam 12, and
- A correction mechanism 30 configured to maintain a constant vertical inclination of the passing light beam 12 with respect to a horizontal reference line H, when the vehicle 2 is moving.

According to the invention, this projector 1 further comprises a dioptric lens 40, having at least one flat incident face 41, configured to suppress at least one shadow zone 5 that may occur, at the level of said lighting zone 3 , between the road light beam 11 and the dipped light beam 12.

It will be noted that the mobile lighting of the second source 20 is in no way limited to being able to provide a correction in elevation, namely a correction in the vertical plane, but could also be configured to be able to provide a correction in azimuth, namely a correction in the horizontal plane. Also, the elevation and/or azimuth correction is also a dynamic correction, that is to say a correction which is carried out, preferably permanently, when the vehicle is moving. Thus, one will not confuse such a correction with an occasional adjustment of the optics conferred by an occasional adjustment system of the latter. Such an adjustment may, for example, be aimed at compensating in a single or occasional manner the attitude of the vehicle due to the load it is transporting, or consist of a manual adjustment of the optics by means of adjustment screws generally manipulated by a mechanic, when technical inspections of the vehicle, for example. Finally, the vertical inclination (namely in elevation) of the crossing light beam 12 with respect to the horizontal reference line V is preferably not zero, as schematically illustrated in FIG. 4, but is rather directed downwards (below the horizontal line H) as illustrated in particular in Figs. 1 to 3.

Thanks to the dioptric lens 40 included in the projector 1 of the present invention, the shadow zone(s) 5 illustrated in Figs. 3 and 4 can advantageously be eliminated, at least in part, without modifying either the first source 10 of fixed matrix lighting, or the second source 20 of mobile lighting. Thus, the technology required by the first matrix lighting source is spared any additional device aimed at making it mobile, which avoids embrittlement or complexification of this first matrix lighting source. In addition, the adaptation of existing headlamps, provided with such first and second light sources, is thereby facilitated by the easy addition of a deflecting member such as the lens 40 in order to be able to obviate the drawback constituted by the shadow zone 5 for the driver of the vehicle. Therefore, the adaptation of such headlamps advantageously finds a solution that is as economical as it is effective.

Fig. 5 is a schematic illustration, in a side view, of the first source 10 of fixed matrix lighting according to the invention. It is noted in this figure that this first source 10 is preferably part of an optical module M preferably comprising a radiator 13 associated with a printed circuit on which is arranged a matrix of light-emitting diodes 15, of a primary optic 17 and of 'a secondary optic 18. As illustrated in this figure, the presence of the diopter lens 40 makes it possible to deflect the light rays A and B in a vertical plane downwards and to respectively obtain the light rays A' and B' before project these towards infinity by means of the secondary optics 18.

The dioptric nature of the lens 40 gives it the ability to be able to refract light and, as a result, to be able to deflect the main beam of light 11 from a certain vertical inclination directed downwards, as schematically illustrated in FIG. 4. The lens 40 is preferably an optical glass lens, for example crown glass, or polymethyl methacrylate (Plexiglas).

According to a preferred embodiment of the invention illustrated by FIG. 6, the diopter lens 40 is movably mounted, in front of the first light source 10, between:
- at least one working position T, making it possible to refract incident rays 11' of the driving light beam 11, and
- a rest position R, with no refraction effect on these incident rays 11'.

Additionally, and as best illustrated in FIG. 5, the dioptric lens 40 comprises an emergence face 42 from which the incident rays 11′ emerge in a refracted beam 11″ intended to project (or configured to project), at the level of the illumination zone 3, the light beam road 11 adjacent to or partially superimposed on the passing light beam 12.

It will be understood that the incident rays 11' are more precisely rays located at the source of the driving light beam 11.

Preferably the incidence face 41 is perpendicular to the optical axis X of the first source 10 of matrix illumination. In other words, the incident rays 11' form an incident beam which, preferably, is perpendicular to the flat incident face 41 of the diopter lens.

In one embodiment, the rest position R is a retracted position of the diopter lens 40 with respect to the incident rays 11'.

Fig. 6 is a schematic illustration of an embodiment in which the diopter lens 40 is mounted so as to move along a translation axis 47. In the rest position, the retracted position of the lens 40 could be a position, along the translation axis 47, located outside the incident rays 11'. The translational movement of the lens 40 can easily be obtained from a simple mechanism using, for example, an actuator such as a stepper motor, a DC motor, a solenoid or a piezoelectric device.

By definition, the diopter lens 40 comprises at least one domed or curved diopter. The interface constitutes a surface separating the transparent media which are the air and the material of the lens 40. These media are considered to be homogeneous and isotropic. Preferably, the diopter lens 40 comprises a curved diopter, more precisely concave, which is constituted by the emergence face 42. The curvature of this diopter or emergence face 42 can be spherical, namely constant, or be variable, preferably progressive.

Preferably again, the emergence face 42 constitutes an at least partially curved dioptre, having a variable deflection power of the refracted beam which depends on the position of the dioptric lens 40 on the translation axis 47. Indeed, the power deviator of the lens diopter depends on the angle φ shown in Fig. 5 and the refractive index n of the lens 40, more particularly the refractive index of the material which constitutes this lens. The angle φ has as its vertex the intersection between an incident ray 11' and the emergence face 42. In addition, this angle has as its first side a parallel to the planar incidence face 41 and as its second side the tangent to the emergence face 42 at the aforementioned vertex. Thus, the value of the angle φ varies as a function of the position of its vertex along the diopter formed by the curvilinear emergence face 42 . Since this position varies according to the location of the lens 40 on the axis of translation 47, the deflecting power of the lens 40 is also variable according to the position occupied by the lens 40 along its axis of translation 47 Therefore, the dioptric lens 40 can advantageously adopt, along this axis of translation, several working positions T.

The deviation of the incident rays 11' is shown in FIG. 5 by a vertical deviation δ, namely a deviation in the vertical plane or in elevation. This deviation is preferably between 1 and 4 degrees so that it has a slope (directed downwards) of the order of 2% to 7%. To obtain such a deviation, the angle φ could vary between values comprised between 2 and 4.5 degrees and the refractive index n of the lens 40 could be comprised between 1.49 and 1.90, thereby including materials such as polymethacrylate of methyl (Plexiglas) as well as the whole range of optical glasses. Advantageously, the different working positions T of the dioptric lens 40 are each associated with a specific vertical deviation angle δ.

In a preferred embodiment, the diopter formed by the emergence face 42 further comprises a portion 43 parallel to the plane incidence face 41 of the diopter lens 40 . Preferably, this portion 43 is located at one of the two ends of the lens 40 which are located outside its optical axis. This portion 43 constitutes, with the portion of the incidence face 41 located opposite, a blade with parallel faces. This blade has the property of not refracting the incident rays 11' and even of not deflecting these rays when the latter are perpendicular to the face of incidence 41. As a result, the parallel portion 43 can also constitute the position of rest R of the lens 40 diopter. Advantageously, this embodiment offers a certain compactness which would make it possible to preserve the existing dimensions of the optical module M dedicated to the first source 10 of illumination.

As illustrated in Figs. 5-6, the first source 10 of matrix lighting preferably consists of a plurality of light-emitting diodes 15 arranged in a matrix fashion on a flat support 14 . Such a support 14 can advantageously consist of the printed circuit on which the LED diodes are arranged. The matrix arrangement of these LEDs can define both 10' vertical lighting strips (Fig. 1) and 10" pixels (Fig. 2). The number of LEDs, 10' vertical lighting strips or pixels 10" remains indifferent. Preferably again, the incident face 41 of the diopter lens 40 is parallel to the flat support 14 .

Preferably again, the primary optic 17 consists of a matrix of converging lenses 17'. In a preferred embodiment, this primary optic is arranged in front of the flat support 14 and the incident face 41 of the lens 40 is located in a focal plane F of the converging lenses 17'. Preferably again, these converging lenses are all identical and therefore all have identical focal lengths. Also, the matrix of converging lenses 17' of the primary optics 17 is preferably arranged in coincidence with the matrix of LEDs so that each LED is associated with a converging lens of the primary optics. Preferably again, the focal plane F of the primary optic 17 also comprises the focal point of the secondary optic 18 (projection lens).

As shown in FIG. 6, the dioptric lens 40 constitutes an activatable and/or deactivatable deflecting member. As shown in FIG. 4, the activation or deactivation of this deflecting member can preferably be controlled by a control signal 51 coming from a control member 50. This control member 50 could be configured to prevent or detect the zone of shadow 5.

In one embodiment, the control device 50 could be a control device for the angle of inclination (site) of the correction mechanism 30 and could be configured to generate and transmit, to the deflector device (lens 40 ), the control signal 51 when the angle of inclination (in the vertical plane) reaches a threshold value. This threshold value could be a predefined value corresponding for example to an angle having a slope (oriented downwards) of 2% or less than this value. The above-mentioned angle of inclination typically corresponds to the attitude of the vehicle 2 and could be determined by the correction mechanism 30 and/or come from the latter.

The control signal 51 could be a binary signal or a more complex signal conveying at least one piece of complementary information or data. Such additional information could consist of a value corresponding to the location of a specific working position T among all the working positions that it might be possible to define along the translation axis 47.

In one embodiment, the control signal 51 consists of:
- an activation signal transmitted to the deflector member (lens 40) when the aforementioned angle of inclination is greater than or equal to the threshold value, and
- A deactivation signal transmitted to the deflector member when this angle of inclination is less than this threshold value.

As a variant, the control signal could consist of a single activation or deactivation signal in the case where the default position of the deflecting member is the rest position R, respectively the working position T. This signal activation could consist of or integrate the location of this working position T along the translation axis 47.

In one embodiment, the control member 50 is a shadow zone detection member 5. Such a member could be a camera or another member of the electro-optical type in particular.

In another embodiment, the control signal 51 is configured to be subordinated to a management unit 60 of the matrix lighting of the first source 10. By this means, it could be possible to deactivate the deflecting unit (lens 40) in the presence of a target located or detected at the level of the lighting zone 3, between the road light beam 11 and the passing light beam 12. Such a target could be a pedestrian or an oncoming vehicle and that it would be advisable not to dazzle so as not to hinder its movement. The management unit 60 could be the same unit as that dedicated to the management of the LEDs of the first matrix lighting source. Such a management unit 60 could therefore include a microcomputer or at least one processor provided with firmware.

In a second aspect, the invention also relates to a vehicle 2, in particular a motor vehicle, comprising a headlight 1 according to any one of the embodiments of this headlight or according to any possible combination of these embodiments .

Claims (10)

Vehicle (2) headlamp (1), configured to generate a lighting zone (3) in front of the vehicle (2) and comprising:
- a first source (10) of fixed matrix lighting configured to emit a road light beam (11),
- a second movable light source (20) configured to emit a passing light beam (12), and
- a correction mechanism (30) configured to maintain a constant vertical inclination of the passing light beam (12) with respect to a horizontal reference line (H), when the vehicle is moving,
characterized in that it further comprises a dioptric lens (40), having at least one flat incidence face, configured to suppress at least one shadow zone (5) that may occur, at the level of said illumination zone (3), between the road light beam (11) and the dipped light beam (12). Projector (1) according to claim 1, characterized in that the dioptric lens (40) is mounted to move, in front of the first light source (10), between:
- at least one working position (T), making it possible to refract incident rays (11') of the road light beam (11), and
- a rest position (R), with no refraction effect on said incident rays (11');
and in that said dioptric lens (40) comprises an emergence face (42) from which emerge said incident rays (11') in a refracted beam (11") intended to project, at the level of the illumination zone ( 3), the road light beam (11) adjacent to or partially superimposed on the passing light beam (12). Projector (1) according to Claim 2, characterized in that:
- the diopter lens (40) is mounted to move along a translation axis (47), and
- said emergence face (42) constitutes an at least partially curved diopter, having a variable deflection power of the refracted beam (11") which depends on the position of the diopter lens (40) on said translation axis (47) . Projector (1) according to Claim 3, characterized in that the said diopter also comprises a portion (43) parallel to the incident face (41) of the diopter lens (40), and the said portion (43) constitutes the position rest (R) of the lens (40) diopter. Headlight (1) according to one of Claims 2 to 4, characterized in that the first lighting source (10) consists of a plurality of light-emitting diodes (15) arranged in a matrix fashion on a flat support (14) and in that the incident face (41) of the diopter lens (40) is parallel to said plane support (14). Projector (1) according to Claim 5, characterized in that a primary lens (17), consisting of a matrix of converging lenses (17'), is arranged in front of the said plane support (14) and in that the face of plane incidence (41) of the diopter lens (40) is situated in a focal plane (F) of said converging lenses (17'). Projector (1) according to one of the preceding claims, characterized in that the dioptric lens (40) constitutes a deflecting member which can be activated and/or deactivated by a control signal (51) coming from a control member (50) configured to prevent or detect said shadow zone (5). Headlight (1) according to Claim 7, characterized in that the control member (50) is a member for controlling an angle of inclination of the correction mechanism (30) and in that it is configured to generate and transmitting, to the diverter member, said control signal (51) when said angle of inclination reaches a threshold value. Projector (1) according to Claim 7 or 8, characterized in that the said control signal (51) is configured to be subordinated to a management unit (60) for the matrix lighting of the first source (10), in order to being able to deactivate the deflecting device in the presence of a target situated, at the level of the lighting zone (3), between the main beam of light (11) and the dipped beam of light (12). Vehicle (2), comprising a headlight (1) according to one of the preceding claims.