VEHICLE HEADLIGHTS

Description

DOMAINE TECHNIQUE

[0001] The present invention relates generally to the field of vehicle headlights, in particular motor vehicles, and in particular to the field of front headlights comprising two lighting sources, one generating a high beam and the other a low beam. ART ANTÉRIEUR

[0002] Vehicle headlamps or headlights generally include adjustment means arranged to ensure adjustment of the azimuth and the site 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 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 provides the advantage of reducing the absorption of a portion of the light (up to 10%) by the material which would constitute the glass.

[0003] The adjustment of the projection beam site may depend, for example, on the load transported at the rear of the vehicle, a load which raises the front of the vehicle and which typically must be compensated for by such an adjustment. More sophisticated systems also allow, while the vehicle is moving, dynamic adjustment so that the beam is never dazzling for oncoming road users. These systems are generally configured to maintain a constant inclination of the beam in the vertical plane relative to a horizontal reference line. Document FR3015003A describes a motor vehicle headlight without glass and comprising two lighting modules equipped with a site adjustment.

[0004] Document FR2745061A describes a motor vehicle headlight which makes it possible to simply and economically generate two light beams, one for a dipped beam function and the other for a main beam function, from a single source and a mirror.

[0005] 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 board for example. These LEDs can be distributed in vertical strips (sometimes called "matrix beam" in English) where each strip operates independently of the other strips. Alternatively, these LEDs can be distributed in pixels ("pixel light" in English) where each LED can be switched on or off independently.

[0006] These matrix lights are referred to as adaptive lighting, known by the acronym ADB for "Adaptive Driving Beam" in English, because they allow the road lighting to be optimized without dazzling the vehicle or the user coming in the opposite direction. Indeed, in these types of lighting intended mainly for the main beam, independent lighting zones have been created within the same beam, so that these zones can be activated or deactivated as needed. The management of the activation of the LEDs, associated with these sectors or lighting zones, can typically be controlled by an electronic unit coupled with a means of detecting the location of a target not to be dazzled within the main beam. Such a detection means can be an infrared camera for example.

[0007] An ADB ("matrix" or "pixel") type lighting module makes the mechanical movements required for site adjustment technically complex. For this reason, headlights equipped with an ABD module for the high beam and a standard module for the low beam only offer site adjustments on the standard module associated with the low beam. The ABD module therefore remains a fixed module, i.e. immobile.

[0008] The main disadvantage of these headlights is that if only one of the two modules can be adjusted in height, a shadow area between the main and dipped beams can sometimes occur and become annoying for the driver.

[0009] Therefore, there is an interest in finding an efficient and more adequate solution which, while remaining economical, allows at least part of the aforementioned drawback to be resolved. CN108016348 discloses a projector according to the preamble of claim 1. RÉSUMÉ DE L'INVENTION

[0010] For this purpose, the present invention relates in a first aspect to a vehicle projector, configured to generate a lighting zone in front of the vehicle and comprising: a first fixed matrix lighting source configured to emit a high beam light, a second mobile lighting source configured to emit a low beam light, and a correction mechanism configured to maintain a constant vertical inclination of the low beam light relative to a horizontal reference line, when the vehicle is moving.

[0011] According to the invention, the vehicle headlight further comprises a dioptric prism configured to eliminate at least one shadow zone which may occur, at the level of said lighting zone, between the main beam and the dipped beam.

[0012] Advantageously, the headlight 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 headlights equipped with a two-beam architecture, one of which constitutes a matrix lighting source. Indeed, thanks to the invention, the shadow zone or at least part of the latter which may occur between the main and dipped beams, in particular when the latter is corrected in site, can be eliminated using a simple compensatory optical means, while keeping the ADB module fixed.

[0013] In one embodiment, the dioptric prism is mounted movably, in front of the first lighting source, between: a working position, allowing incident rays of the road light beam to be refracted, and a rest position, without effect on said incident rays; and in that said dioptric prism comprises: a flat incidence face, and a flat diopter from which said incident rays emerge from the diopter prism in a refracted beam intended to project, at the level of the lighting zone, the main beam adjacent to or partially superimposed on the dipped beam.

[0014] Preferably, the dioptric prism comprises an angle, defined by said incidence face and said plane dioptre, configured to induce a vertical deviation of said incident rays of between 1 and 4 degrees.

[0015] In one embodiment, the rest position is a retracted position of the dioptric prism relative to the incident rays.

[0016] According to one embodiment, the dioptric prism is mounted to be mobile in rotation around an axis of rotation located outside said incident rays.

[0017] According to another embodiment, the dioptric prism is mounted to move in translation along a translation axis.

[0018] Preferably, the first lighting source consists of a plurality of light-emitting diodes arranged in a matrix manner on a flat support and in that the incidence face of the dioptric prism is parallel to said flat support.

[0019] In one embodiment, a primary optic, consisting of a matrix of converging lenses, is arranged in front of said flat support and in that the incidence face of the prism is located in a focal plane of said converging lenses.

[0020] In a preferred embodiment, the dioptric prism 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.

[0021] In a second aspect, the invention also relates to a vehicle, in particular a motor vehicle, comprising a headlight according to any one of the embodiments of this headlight or according to any possible combination of these embodiments. BRÈVE DESCRIPTION DES FIGURES

[0022] [ Fig. 1 ] is a schematic illustration of an illumination area obtained by a first matrix illumination source of a first type and by a second standard illumination source; [ Fig. 2 ] is a schematic illustration, similar to that of the Fig. 1 , wherein the first matrix lighting source is of a second type; [ Fig. 3 ] is a schematic illustration of the shadow area that may occur between the beams of the aforementioned first and second lighting sources; [ Fig. 4 ] is a schematic illustration of the main elements of a projector according to the present invention; [ Fig. 5 ] is a schematic illustration, in a side view, of the first fixed matrix lighting source according to the invention; [ Fig. 6 ] is an illustration of an embodiment of the invention in a view similar to that of the Fig. 5 ; And [ Fig. 7 ] is an illustration of another embodiment of the invention according to a representation similar to that of the Fig. 6 . DESCRIPTION DÉTAILLÉE

[0023] In reference to the Fig. 1 , this 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 described as partial lighting zones, because they only form the lighting zone 3 when they are considered together.

[0024] An orthonormal reference frame formed of 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 vertical lighting strips 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 vertical lighting strip 10' can be switched on or off independently.

[0025] 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 association of an infrared camera or any other on-board system for detecting (in night conditions) a target likely to be dazzled, can then be able to select the vertical lighting strips 10' which, for example, must be switched off so as not to disturb the target, in particular when it is a vehicle or a pedestrian coming in the opposite direction. This first source 10 of matrix lighting can be described as adaptive since it is capable of dynamically generating an adaptive or adjustable beam. For this reason, such a type of lighting is generally known by the acronym ADB ("Adaptive Driving Beam").

[0026] If the first matrix lighting source 10 is typically used as a high beam, the second, more modest lighting source is generally dedicated to the dipped beam. This second source 20 is not ordinarily of the matrix type but is more conventionally made up of a bulb, for example a halogen or xenon bulb.

[0027] To improve the driver's night vision and not dazzle oncoming road users, an additional measure is still applied to the headlights of recent vehicles. This measure consists of dynamically correcting the site illumination of the second source 20 dedicated to the dipped headlights. As a reminder, such an adjustment consists of varying the average projection angle of the dipped beam light in the vertical plane, so as to correct the height of the partial lighting zone 32 relative to a horizontal reference line or axis H. The correction is carried out dynamically, namely at all times while the vehicle is moving. Typically, the upper radius of the main beam light will generally be adjusted so that it is at an inclination of 0.57° below the horizontal reference line H. This inclination corresponds to an angle having a slope of 1% oriented downwards from the source.

[0028] There Fig. 2 represents a variant of the illustration given in the Fig. 1 . Indeed, in the Fig. 2 , the matrix lighting of the first source 10 is a "pixel" type lighting in which the vertical lighting strips 10' have been further subdivided by horizontal lines so as to obtain a multitude of pixels 10". Each pixel 10" can be made up of an LED diode or a grouping of a plurality of LED diodes. The advantage of such a lighting source lies in the fact that the granulometry of the lighting offers a finer partitioning than that provided by the first source 10 shown in Fig. 1 .

[0029] There Fig. 3 schematically represents the main problem presented by projectors equipped with lighting sources 10, 20, such as those illustrated indifferently in Figs. 1 ou 2 . Because one of the two lighting sources, in particular the second source 20 generating the dipped light beam, is dynamically corrected in site, a shadow zone 5 may sometimes appear in the lighting zone 3, between the partial lighting zones 31, 32. This shadow zone 5 occurs depending on the inclination or attitude of the vehicle relative to the profile of the terrain and may constitute a nuisance for the driver of the vehicle in particular. The object of the present invention aims in particular to overcome, at least in part, this drawback.

[0030] It should be noted that due to the complexity of the optical module required for the first matrix lighting source 10, this lighting is preferably made fixed or immobile. Consequently, the first source 10 generating the main beam of light must be considered as not being able to be tilted in elevation, unlike the second source 20 generating the dipped beam of light.

[0031] As represented very schematically in the Fig. 4 , to solve at least in part the aforementioned problem, the object of the present invention proposes in its first aspect a projector 1, of vehicle 2, configured to generate a lighting zone 3 at the front of the vehicle 2. This projector or front vehicle headlight can be provided with a protective glass or preferably be without such a glass.

[0032] The projector 1 of the present invention comprises: a first fixed matrix lighting source 10 configured to emit a main beam 11, a second mobile lighting source 20 configured to emit a dipped beam 12, and a correction mechanism 30 configured to maintain a constant vertical inclination of the dipped beam 12 relative to a horizontal reference line H, when the vehicle 2 is moving.

[0033] According to the invention, this projector 1 further comprises a dioptric prism 40 configured to eliminate at least one shadow zone 5 which may occur, at the level of said lighting zone 3, between the main beam 11 and the dipped beam 12.

[0034] 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 correction in elevation and / or in azimuth is also a dynamic correction, that is to say a correction which is carried out, preferably permanently, when the vehicle is moving. Thus, such a correction will not be confused with an occasional adjustment of the optics provided by a system for occasional adjustment of the latter. Such an adjustment may for example aim to compensate in a unique or occasional manner for the attitude of the vehicle due to the load it is carrying, or consist of a manual adjustment of the optics by means of adjustment screws generally manipulated by a mechanic, during technical inspections of the vehicle for example.Finally, the vertical inclination (i.e. in elevation) of the dipped light beam 12 relative 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 on the Figs. 1 à 3 .

[0035] Thanks to the dioptric prism that the projector 1 of the present invention comprises, the shadow zone(s) 5 illustrated in Figs. 3 et 4 can advantageously be eliminated, at least in part, without modifying either the first fixed matrix lighting source 10 or the second mobile lighting source 20. Thus, the technology required by the first matrix lighting source is spared any additional device intended to make it mobile, which avoids weakening or complicating this first matrix lighting source. In addition, the adaptation of existing headlights, provided with such first and second lighting sources, is facilitated by the easy addition of a deflecting member such as the prism 40 to be able to overcome the disadvantage that the shadow zone 5 constitutes for the driver of the vehicle. As a result, the adaptation of such headlights advantageously finds a solution that is both economical and effective.

[0036] There Fig. 5 is a schematic illustration, in a side view, of the first fixed matrix lighting source 10 according to the invention. It can be seen 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, a primary optic 17 and a secondary optic 18. As illustrated in this figure, the presence of the dioptric prism 40 makes it possible to deflect the light rays A and B in a vertical plane downwards and to obtain respectively the light rays A' and B' before projecting the latter towards infinity by means of the secondary optic 18. This secondary optic 18 can typically be constituted by a projection lens.

[0037] The dioptric character of the prism 40 gives it the ability to refract light and, as a result, to deflect the road light beam 11 by a certain vertical inclination directed downwards, as schematically illustrated in Fig. 4 . The prism 40 is preferably a prism made of optical glass, for example crown glass, or polymethyl methacrylate (Plexiglas). The deflecting power of the dioptric prism depends on the angle ϕ of the prism and its refractive index n, more particularly on the refractive index of the material which constitutes this prism.

[0038] According to a preferred embodiment of the invention illustrated by the Figs. 6 And 7 , the dioptric prism 40 is mounted movably, in front of the first lighting source 10, between: a working position T, allowing incident rays 11' of the road light beam 11 to be refracted, and a rest position R, with no effect on these incident rays 11'.

[0039] Furthermore, and as better illustrated in the Fig. 5 , the 40 dioptric prism includes: a plane incidence face 41, and a plane diopter 42 from which the incident rays 11' emerge from the diopter prism 40 in a refracted beam 11" intended to project (or configured to project), at the level of the lighting zone 3, the main beam 11 adjacent to or partially superimposed on the dipped beam 12.

[0040] It will be understood that the incident rays 11' are more precisely rays located at the source of the road light beam 11.

[0041] Preferably, the incidence face 41 is perpendicular to the optical axis X of the first matrix lighting source 10. In other words, the incident rays 11' form an incident beam which, preferably, is perpendicular to the incidence face 41 of the dioptric prism. The plane dioptric prism 42 constitutes a surface separating the transparent media that are air and the material of the prism. These media are considered to be homogeneous and isotropic.

[0042] As illustrated in the Fig. 5 , the angle ϕ of the prism is defined by the incidence face 41 and by the plane diopter 42. Preferably, the angle ϕ of the prism is configured to induce a vertical deviation δ, namely a deviation in the vertical plane or in elevation, of the incident rays 11'. 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 of the prism could be between 2 and 4.5 degrees and the refractive index n of the prism 40 could be between 1.49 and 1.90, thus including materials such as polymethyl methacrylate (Plexiglas) as well as the entire range of optical glasses.

[0043] In one embodiment, the rest position R is a retracted position of the dioptric prism 40 relative to the incident rays 11'.

[0044] There Fig. 6 is a schematic illustration of an embodiment in which the dioptric prism 40 is mounted to be movable in rotation around an axis of rotation 45 located outside of said incident rays 11'. Advantageously, this embodiment is a relatively compact mode which would make it possible to preserve the existing dimensions of the optical module M dedicated to the first lighting source 10.

[0045] There Fig. 7 is a schematic illustration of another embodiment in which the dioptric prism 40 is mounted to move in translation along a translation axis 47.

[0046] Regardless of the manner in which the prism 40 is made movable, this mobility can be easily obtained from a simple mechanism using, for example, an actuator such as a stepping motor, a continuous motor, a solenoid or a piezoelectric device.

[0047] As illustrated on the Figs. 5-7 , the first matrix lighting source 10 is preferably made up of a plurality of light-emitting diodes 15 arranged in a matrix manner on a flat support 14. Such a support 14 can advantageously be made up of the printed circuit on which the LEDs are arranged. The matrix arrangement of these LEDs can define both vertical lighting strips 10' ( Fig. 1 ) than 10" pixels ( Fig. 2 ). The number of LEDs, 10' vertical lighting strips or 10" pixels remains indifferent. Preferably again, the incidence face 41 of the dioptric prism 40 is parallel to the plane support 14.

[0048] More preferably, the primary optics 17 consists of a matrix of converging lenses 17'. In a preferred embodiment, this primary optics is arranged at the front of the plane support 14 and the incidence face 41 of the prism 40 is located in a focal plane F of the converging lenses 17'. More preferably, 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 for each LED there is associated a converging lens of the primary optics. More preferably, the focal plane F of the primary optics 17 further comprises the focal point of the secondary optics 18 (projection lens).

[0049] As shown in the Figs. 6 And 7, the 40 dioptric prism constitutes an activatable and / or deactivatable deflecting member. As shown in the Fig. 4 , the activation or deactivation of this deflecting member can, preferably, be controlled by a control signal from a control member 50. This control member 50 could be configured to prevent or detect the shadow zone 5.

[0050] In one embodiment, the control member 50 could be a member for controlling the tilt angle (site) of the correction mechanism 30 and could be configured to generate and transmit, to the deflecting member (prism 40), the control signal 51 when the tilt angle (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 aforementioned tilt angle typically corresponds to the attitude of the vehicle 2 and could be determined by the correction mechanism 30 and / or be derived from the latter.

[0051] The control signal 51 could be a binary signal or a more complex signal carrying at least one additional piece of information or data.

[0052] In one embodiment, the control signal 51 consists of: an activation signal transmitted to the deflecting member (prism 40) when the tilt angle is greater than or equal to the threshold value, and a deactivation signal transmitted to the deflecting member when the tilt angle is less than this threshold value.

[0053] Alternatively, the control signal could consist of a single activation or deactivation signal in the case where the default position of the deflector member is the rest position R, respectively the working position T.

[0054] In one embodiment, the control member 50 is a member for detecting the shadow zone 5. Such a member could be a camera or another member of the electro-optical type in particular.

[0055] In another embodiment, the control signal 51 is configured to be subordinate to a management member 60 of the matrix lighting of the first source 10. By this means, it could be possible to deactivate the deflecting member (prism 40) in the presence of a target located or detected at the level of the lighting zone 3, between the main beam 11 and the dipped beam 12. Such a target could be a pedestrian or a vehicle coming in the opposite direction and which should not be dazzled so as not to hinder its movement. The management member 60 could be the same member as that dedicated to the management of the LEDs of the first matrix lighting source. Such a management member 60 could therefore include a microcomputer or at least one processor provided with micro-software.

[0056] In a second aspect, the teaching 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.

[0057] Additional features relate, in a first aspect, to a vehicle projector, configured to generate an illumination zone in front of the vehicle and comprising: a first fixed matrix lighting source configured to emit a high beam light, a second mobile lighting source configured to emit a low beam light, and a correction mechanism configured to maintain a constant vertical inclination of the low beam light relative to a horizontal reference line, when the vehicle is moving.

[0058] Preferably, the control member is a member for controlling an angle of inclination of the correction mechanism and this member is configured to generate and transmit, to the deflecting member, said control signal when said angle of inclination reaches a threshold value.

[0059] In another embodiment of the first aspect of the additional characteristics, said control signal is configured to be subordinate 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 beam and the dipped beam.

[0060] A second aspect of the additional features 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.

Claims

1. A vehicle headlight (1) (2), configured to generate a lighting zone (3) in front of the vehicle (2) and comprising: - first fixed matrix lighting source (10) configured to emit a driving light beam (11), - second movable lighting source (20) configured to emit a dipped light beam (12), and - correction mechanism (30) configured to maintain a constant vertical inclination of the dipped light beam (12) with respect to a reference horizontal line (H), when the vehicle is traveling, characterized in that it further comprises a dioptric prism (40) configured to eliminate at least one shadow zone (5) which may occur, at the level of said lighting zone (3), between the driving light beam (11) and the dioptric light beam (12), and characterized in that the dioptric prism (40) is mounted so as to be movable, in front of the first lighting source (10), between: - working position (T), making it possible to refract incident rays (11' ) of the driving light beam (11), and - a rest position (R), with no effect on said incident rays (11' ); and in that said dioptric prism (40) comprises: - a plane bearing face (41), and - a diopter (42) plane of which said incident rays (11 ' ) emerge from the dioptric prism (40) into a refracted beam (11 " ) intended to project, at the level of the lighting zone (3), the driving light beam (11) adjacent or partially superposed on the dipped light beam (12).

2. Headlight (1) according to claim 1, characterized in that the dioptric prism (40) comprises an angle (ϕ) defined by said incidence face (41) and said planar diopter (42), configured to induce a vertical deviation (δ) of said incident rays (11') of between 1 and 4 degrees.

3. Projector (1) according to claim 1 or 2, characterized in that the rest position (R) is a retracted position of the dioptric prism (40) with respect to the incident rays (11').

4. Headlight (1) according to any one of claims 1 to 3, characterized in that the dioptric prism (40) is mounted to be movable in rotation about an axis of rotation (45) situated outside said incident radii (11').

5. Headlight (1) according to any one of claims 1 to 3, characterized in that the dioptric prism (40) is mounted so as to be movable in translation along a translation axis (47).

6. Projector (1) according to one of claims 1 to 5, characterized in that the first lighting source (10) consists of a plurality of light-emitting diodes (15) arranged in a matrix manner on a plane support (14) and in that the incidence face (41) of the dioptric prism (40) is parallel to said plane support (14).

7. Projector (1) according to claim 6, characterized in that a primary optic (17), consisting of a matrix of convergent lenses (17'), is arranged in front of the said plane support (14) and in that the incidence face (41) of the prism (40) is situated in a focal plane (F) of the said convergent lenses (17').

8. Headlight (1) according to claim 1, wherein the dioptric prism (40) constitutes a deflecting member that 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).

9. Vehicle (2), comprising a headlight (1) according to one of the preceding claims.