Method for controlling a light beam and corresponding lighting system

Description

[0001] The invention relates to the field of lighting and / or signaling, in particular for motor vehicles. More particularly, the invention relates to a method for controlling an overall light beam emitted by a motor vehicle headlight and obtained by the addition of intermediate beams produced by at least two lighting means, as well as to the light modules which can allow the implementation of such control methods.

[0002] A motor vehicle is equipped with headlamps, or headlights, designed to illuminate the road ahead of the vehicle at night or in low light conditions. These headlamps can generally be used in two lighting modes: a first "high beam" mode and a second "low beam" mode. The "high beam" mode allows the road to be brightly illuminated far ahead of the vehicle. The "low beam" mode provides more limited illumination of the road, but still offers good visibility, without dazzling other road users. These two lighting modes are complementary. The driver of the vehicle must manually change the mode depending on the circumstances, at the risk of inadvertently dazzling another road user. In practice, changing lighting modes manually can be unreliable and sometimes dangerous.In addition, the low beam mode sometimes provides unsatisfactory visibility for the vehicle driver.

[0003] To improve the situation, headlights equipped with an adaptive lighting function (known in particular by the English acronym AFS for "Adaptative Frontlighting System") have been proposed. Such an adaptive lighting function is intended to automatically detect, for example by processing an image acquired by an on-board camera, a road user likely to be dazzled by a lighting beam emitted in high beam mode by a headlight, and to modify the contour of this lighting beam so as to create a shadow zone at the location of the detected user. The advantages of such an adaptive lighting function are multiple: ease of use, better visibility compared to lighting in dipped beam mode, better reliability for changing mode, significantly reduced risk of dazzling, safer driving.

[0004] Document EP2280215 describes an example of a lighting system for a motor vehicle headlight, having an adaptive lighting function. The system comprises four primary optical elements, in each of which three light sources are associated with three respective light guides, as well as four secondary projection optical elements, in this case lenses, respectively associated with the four primary optical elements. The light emitted by each light source enters the associated light guide and exits through a rectangular exit end of the guide. The arrangement of the primary optical elements and their associated secondary optical element causes the light emitted by each optical guide exit end to be projected by the secondary optical element so as to form a vertical light segment at the front of the vehicle. The light segments produced partially overlap in the horizontal direction.The actuation of the light sources is then played on, which can be switched on independently of each other, selectively, to obtain the desired lighting and produce a complementary main beam, which is not dazzling for other road users. The beam is thus divided into a plurality of light segments which can be activated or deactivated. The adaptive lighting beam which can thus be produced solely by electronic control of the switching on of the light sources, and without mechanical movement of an additional cover part, is known in particular under the name of matrix beam. Documents US2006023461 A1, WO2015022115 A1 and KR20140080156 A disclose other known lighting methods and systems.

[0005] Furthermore, it is increasingly common to see motor vehicles equipped with a directional lighting function, better known by the English acronym DBL (for Dynamic Bending Light), in which the objective is to illuminate the road and its verges when the vehicle turns. The headlight is mounted pivoting around a substantially vertical axis of rotation, and therefore when turning, the beam projected from the headlight is no longer oriented in the longitudinal axis of the vehicle but towards the inside of the turn.

[0006] The invention aims to propose a method for controlling light beams which manages both the creation of a matrix beam and the creation of a directional beam and which can manage the transition from one to the other.

[0007] For this purpose, the invention relates to a method for controlling, according to claim 1, a global light beam emitted by a motor vehicle headlight and formed of beam portions that can be selectively activated and produced independently of each other by lighting means carried by said headlight, all of the portions forming a global light beam when they are all activated and arranged successively side by side. According to the method of the invention, provision is made to compare the instantaneous speed of the vehicle with a first predetermined speed threshold, and to determine a zone of high lighting intensity to be produced when the instantaneous speed is greater than the first predetermined speed threshold.

[0008] In particular, it may be provided, in a particular embodiment, that the overall light beam according to the invention forms a complementary main beam, segmented by the presence of beam portions, and intended to be associated with a dipped beam, for example by being juxtaposed or superimposed on the dipped beam to form a main beam.

[0009] It can be understood that the successive arrangement side by side of the bundle portions generates or not a partial overlap of two successive portions. It will thus be possible to have an arrangement in which the bundle portions are juxtaposed, edge to edge, so as to be joined two by two, and it will be possible to have an arrangement in which the bundle portions are juxtaposed and partially superimposed so as to allow a partial overlap of one portion by another portion.

[0010] According to the invention, it is identified which of said lighting means produce the beam portions suitable for ensuring the illumination of said high lighting intensity zone, and a movement of said lighting means identified in the previous step is controlled, and a movement of the lighting means adjacent to the lighting means identified in the previous step is controlled, so as to create a first specific overall light beam comprising said high lighting intensity zone. The lighting means are moved so as to cause at least partial superposition of the beam portions produced by these identified lighting means, in the high lighting intensity zone.It is understood that it is possible to identify, for example, a portion of target beam, produced by a target lighting means, as a zone of high lighting intensity to be produced and that it is subsequently possible to control two lighting means producing neighboring beam portions arranged on either side of the portion of target beam so as to cause a superposition of these neighboring beam portions and the portion of target beam.

[0011] According to the invention: all of said lighting means are kept lit; all of the beam portions are moved to maintain continuity of lighting on either side of the high lighting intensity zone; the first specific overall light beam is ensured to have a width less than that of the overall light beam.

[0012] According to features of an implementation mode, in which different speed levels of the vehicle are taken into account, the instantaneous speed of the vehicle is compared to at least one second predetermined speed threshold, of a greater value than the value of said first speed threshold, and, when the instantaneous speed is greater than said second speed threshold, the light intensity of said high-intensity lighting zone is increased by superimposing other beam portions and by concentrating the overall light beam; regardless of the first or second threshold beyond which the speed of the vehicle is detected, the direction of travel of the vehicle is detected, and, when a straight-line driving situation is detected, said high-intensity lighting zone is arranged, by superimposing beam portions, substantially in the center of the overall light beam.

[0013] According to the invention, the detection is carried out, on a road scene in the vicinity of the vehicle, of a specific situation in which a third-party vehicle is likely to be dazzled by said overall light beam. In this case, a first target zone is determined in said overall beam including said third-party vehicle, and then lighting means carried by said projector are identified which produce the beam portions ensuring the lighting of said first target zone. A movement of said lighting means identified in the previous step is then controlled, so as to create a zone of lesser illumination corresponding to said first target zone, said zone of high lighting intensity then being split into two sub-zones arranged on either side of said zone of lesser illumination.

[0014] According to other characteristics of the invention, it is possible to detect, on a road scene in the vicinity of the vehicle, a specific situation in which the vehicle is faced with a bend. In this case, a second target zone is determined in said overall beam as a function of the characteristics of the bend, and then lighting means carried by said projector are identified which produce the beam portions ensuring the lighting of said second target zone. A movement of said lighting means identified in the previous step is then controlled, so as to create a second zone of high lighting intensity corresponding to said second target zone.

[0015] In these last two cases, the lighting means are controlled, when it is detected that said specific situation is over, to respectively take up a position capable of creating said first specific global light beam.

[0016] According to another series of characteristics of the invention, taken alone or in combination with the preceding: said lighting means comprise light sources and optical deflection means associated respectively with at least one of the light sources, each light source being individually controlled in terms of ignition while said optical deflection means are individually controlled in terms of movement; the overall light beam consists of a complementary, non-segmented, matrix beam type road beam; the overall light beam is obtained by the addition of intermediate beams produced respectively by separate sets of lighting means, and in which the lighting means of each set are controlled in terms of movement to create the high lighting intensity zone;the beam portions consist of vertical segments juxtaposed with each other, the movement of the lighting means generating the movement of at least one of said segments and its superposition on other segments of the overall light beam.;

[0017] The invention also relates to an automotive lighting system according to claim 7 comprising a left headlight and a right headlight, each comprising at least one light module for implementing the control method as just presented, and which notably comprises at least one light source and movably mounted optical deflection means.

[0018] According to different characteristics specific to such a light module: an optical system is provided for emitting a light beam, the optical deflection means being interposed between the light source and the optical system; the optical system consists of a reflector and a projection lens; the light source comprises a plurality of semiconductor sources; the optical deflection means consist of optical microelectromechanical systems, mounted to be movable in rotation between two end positions, said optical microelectromechanical systems being capable of taking at least one predetermined intermediate position between the two end positions; the optical microelectromechanical systems are mounted to be movable in rotation to pass from one to the other of the end positions, with an angle of rotation of between 2° and 7°;each optical electromechanical microsystem consists of a mirror capable of deflecting the light rays emitted by the light source and mounted on a rotation axis carried by the module; the electromechanical microsystems are arranged in a linear matrix; a primary optical device is provided, in particular a collimation or focusing lens, arranged between the light sources and the optical deflection means.

[0019] The invention may also relate to an automotive lighting system comprising at least one light module as presented previously, as well as at least means for detecting the instantaneous speed of the vehicle, means for analyzing the detection information received and calculation means, comprising at least means for comparing the instantaneous speed with respect to at least one predetermined threshold, to give instructions for controlling the movement of the optical deflection means, on the basis of at least one piece of information on the speed of the vehicle.

[0020] In such a lighting system at least one light module as presented previously is arranged in a left headlight of the motor vehicle and at least one light module as presented previously is arranged in a right headlight of the vehicle, said modules being arranged so that the intermediate light beams that they generate add up to form an overall light beam.

[0021] The lighting system may further comprise means for detecting a third-party vehicle on a road scene, and / or means for detecting a bend extending in front of the vehicle.

[0022] Other features and advantages of the present invention will become more clearly apparent from the description and the drawings, among which: there figure 1 is a schematic representation, seen from the side, of a light module according to the invention, in which a light source, a collimation lens, optical deflection means, a reflector and a projection lens are made visible here; figure 2 is a schematic representation of the module of the figure 1 , top view, in which the reflector is made transparent to facilitate the visibility of the optical deflection means, and the axes of rotation of the microelectromechanical systems which compose them; and the figures 3 à 5 are diagrams illustrating the operation of the invention in which intermediate beams are pivoted to modify the overall light beam emitted by a motor vehicle headlight, according to an embodiment in which the overall light beam is modified solely as a function of the speed of the vehicle ( figure 3 ), according to an implementation mode in which the overall light beam is further modified as a function of the detection of a turning situation ( figure 4 ), and according to an implementation mode in which the overall light beam is further modified as a function of the detection of a vehicle which may be dazzled ( figure 5 ).

[0023] We will first describe a light module for lighting and / or signaling a motor vehicle according to a first embodiment illustrated in the figures 1 et 2 . The light module 2 comprises at least one light source 4 capable of emitting light rays in the direction of first optical deflection means 6, and an optical system 8. At the output of the module, an intermediate beam is thus produced, capable of being completed by adding other intermediate beams obtained by other light modules arranged nearby in the same headlight of the motor vehicle or in another headlight, so as to form an overall light beam. In the description which follows, the term optical plane will be used to define the vertical plane comprising the optical axis, it being noted that the optical plane corresponds to the plane of the sheet in the illustration of the figure 1 .

[0024] As will be described below, at least the first optical deflection means are controlled so that, when the instantaneous speed of the vehicle is greater than a first predetermined speed threshold, a portion of the overall light beam is concentrated to form a zone of high lighting intensity, i.e. an area illuminated more strongly than the immediately neighboring zones.

[0025] Each light source here consists of a semiconductor source, for example a light-emitting diode, which can be associated with a printed circuit board and a radiator for cooling the electronic components carried by said board.

[0026] As seen on the figure 2 , the module comprises three separate light-emitting diodes 10 attached to a common printed circuit board 12. It will be understood that other configurations, in number and geometric arrangement, may be chosen without departing from the context of the invention. In particular, in the future description of preferred embodiments of the invention, it will be specified that a vehicle lighting system may comprise a first module in which three diodes are capable of producing three beam portions and a second module in which four diodes are capable of producing four beam portions, these seven portions being juxtaposed and / or superimposed to form an overall light beam.

[0027] The first optical deflection means 6 consist of a plurality of microelectromechanical systems (known by the acronym MEMS for the English translation "MicroElectroMechanical Systems"), arranged in a row matrix such that each of these microelectromechanical systems is arranged opposite a light-emitting diode (or an individually addressable "light chip" of the diode). The microelectromechanical systems extend longitudinally in front of the light sources, and they consist of movable mirrors 14 capable of reflecting a portion of the light rays emitted by the light source.

[0028] Each mirror 14 is mounted to rotate about an axis 16 carried by the module, so as to pivot between two end positions, obtained by mechanical stop of the rotation of the axis. Depending on the position of the mirrors in the series, and therefore depending on the centered or eccentric position of the portion of light beam generated by this mirror, a standard position of each mirror is defined as being one of the two end positions, or as the position at the center of the two end positions. For a diode centered on the optical axis and the associated microelectromechanical system also centered on the optical axis, the first standard position is calibrated so that the rays reflected by the mirror thus oriented impact the optical system arranged downstream substantially in the optical plane, and the two end positions are calibrated,either on either side of the first standard position so that the rays reflected by the mirror thus oriented impact the optical system at a distance from the optical plane corresponding to half the desired width of the light segments making up the intermediate light beam, or with one of the end positions corresponding to the standard position, and the other end position calibrated so that the rays reflected by the mirror thus oriented impact the optical system at a distance from the optical plane corresponding to the desired width of the light segments making up the intermediate light beam, in the direction of approaching the center of the overall light beam.,

[0029] It is understood that when all the mirrors are in the standard position, we obtain regular intermediate beams, with segments composing it arranged at regular intervals. On the other hand, if only one of the mirrors of the optical deflection means is pivoted, the intermediate beam is no longer regular, and the superposition of the two intermediate beams implies a superposition of two segments of the matrix beam, and therefore an area of ​​higher light intensity.

[0030] In the advantageously narrow angular range of rotation, of the order of 2° to 7°, the light reflected by the mirrors in one or other of the extreme positions is directed entirely towards the projection device arranged downstream in the path of the light rays. In their first end position, the optical deflection means are capable of deflecting the light rays towards a first zone of the optical system and in their second end position, the same deflection means are capable of deflecting the light rays towards a second zone of the optical system.

[0031] It is also particularly interesting to note that the microsystems used in the invention are not binary. This means that the rotation angle can be chosen indifferently within the angular range of + / - 7°, without being limited to one or other of the extreme positions, by voltage or current control instructions depending on the type of microsystems chosen, electrostatic, piezoelectric or magnetic control for example.

[0032] In particular, it is possible to provide for each microsystem predefined intermediate positions, which can be taken by these microsystems to form a portion of beams associated with a predefined state as will be described below.

[0033] Optionally, a primary optic is arranged between the first optical deflection means and the light source, in addition to the optical system arranged at the output of the module, to improve efficiency and avoid beam overlaps. This primary optic may be a collimating or focusing lens 18.

[0034] The optical system 8 is arranged at the output of the module on the path of the light rays emitted by the light-emitting diode 10 and deflected by the mirrors 14. As illustrated, the optical system comprises a reflector 20 and a projection lens 22. It will be understood that other optical system arrangements can be implemented without departing from the context of the invention.

[0035] The module further comprises means for controlling the light sources and the electromechanical microsystems, capable of controlling on the one hand the switching on, switching off or modification of the light intensity emitted by each light source of each module, and on the other hand the rotation of the electromechanical microsystems as a function of information on the vehicle's traffic conditions, among which the control means receives at least one piece of information for detecting the forward speed of the vehicle. This information can be obtained by a sensor specific to the control method according to the invention, or else be taken from a vehicle information network. The control means comprise means for analyzing any information transmitted by these detection means.

[0036] Other traffic condition information may be obtained and provided to the control means, and in particular, detection means may be provided on the illuminated road scene of a vehicle not to be dazzled, and / or means for detecting the presence of a bend in front of the vehicle. The detection means may consist, for example, of a camera facing the road scene extending in front of the vehicle, and associated image processing means, which allow the development of detection information that the detection module is capable of sending to the control means for the rotation of the microelectromechanical systems. The means for detecting the presence of a bend in front of the vehicle may consist of a vehicle angular speed sensor, or an on-board satellite navigation system.

[0037] A light module 2 as just described allows the implementation of the method for controlling an overall light beam emitted by a motor vehicle headlight and obtained by the addition of intermediate beams produced by at least two lighting means according to the invention.

[0038] Initially, light rays are emitted by the diodes 10 of the module 2 when the control module receives information relating to the automatic detection of driving conditions in high beam or information relating to a command from the driver.

[0039] The rays are directed substantially parallel to the optical axis towards the microelectromechanical systems formed of movable mirrors 14 which are in the first standard position, and this results in an intermediate beam of the "high beam" type, divided into a number of segments equal to the number of diodes, and corresponding mirrors, provided for the entire lighting system.

[0040] Depending on the information sent by the detection means to the control module, whether it relates to the speed of the vehicle on the one hand, and to the presence of a vehicle on the road scene illuminated by the beam previously produced or to the presence of a bend in front of the vehicle on the other hand, the control module identifies which is the zone of high lighting intensity to be produced, and possibly the zone in which a detected vehicle is present, and it determines which are the diodes and the associated electromechanical microsystems to move to produce the appropriate lighting of these zones.

[0041] The light rays deflected by a mirror represent a light segment, here vertical, of the intermediate beam and the rotation of a few degrees of a mirror generates a transverse displacement of the corresponding light segment. As was previously specified, it is possible to provide at least one intermediate position that the mirror can take to generate an intermediate position of the corresponding beam portion, between the standard position in which it forms the overall light beam and an end position.

[0042] We will now describe, with reference to the figures 3 à 5 , different modes of implementation of the control method. In each of these modes of implementation, the overall light beam is obtained by the addition of two complementary intermediate light beams, in the case of a motor vehicle lighting assembly in which two light modules as just described are housed in series in a projector whose overall light beam is shown on the right of the figures, resulting from the addition of the intermediate beams of the two modules shown on the left of the figures.

[0043] Each of these figures illustrates a lighting sequence for which the different states of the overall light beam have been successively represented, from top to bottom, with portions 23 of light beam projected onto a vertical wall, according to the information received by the control means associated with each module, the figure 3 illustrating in more detail the different states of the intermediate beam portions and the resulting combination to form the overall light beam, while the figures 4 et 5 only show the overall light beam.

[0044] Each of these figures illustrates an implementation mode taking into account the speed information as provided by the present invention.

[0045] On the figure 3 , the case where only the speed information is taken into consideration has been illustrated. The first line corresponds to a standard state with a forward speed of the vehicle lower than a first predetermined speed threshold. A first module comprises three diodes, and when these are lit, a first intermediate beam 24 is formed, by reflection of the light emitted on the optical deflection means in particular, consisting of three segments 2g, 0, 2d, spaced from each other, in the transverse direction, by a first determined interval d1. A second module comprises four diodes, and when these are lit, a second intermediate beam 26 is formed consisting of four segments 3g, 1g, 1d, 3d, spaced from each other, in the transverse direction, by a second determined interval d2.The modules are oriented relative to the optical axis of the vehicle, so that, by adding the two intermediate beams, an overall light beam 28 is formed composed of a succession of beam portions 23, here in the form of segments, it being understood that the segments of the first intermediate beam have a width equal to the second interval d2 to be housed between the segments of the second intermediate beam and that conversely the segments of the second intermediate beam have a width equal to the first interval d1 to be housed between the segments of the first intermediate beam. As illustrated, it can be provided that the segments all have the same dimension and that the intervals between the segments are the same from one intermediate beam to another. It should be noted that according to the invention, the width of the segments can vary from one segment to another depending on whether they are positioned in the center of the beam or on the edges.The central segments are thus designed to be narrower than the lateral segments. In the same vein of a non-homogeneous arrangement according to the position of the segments, the intervals between the segments of a sub-beam can vary, and the angles of rotation of the segments can differ from one segment to another.

[0046] It is understood that the segments at the edge of the beam can be provided to be fixed and to be controlled simply by switching off or switching on. This avoids having to manage a high value rotation angle for their movement, which is complicated to implement, while this movement may not be justified given the position of the segment on the road. The system can therefore combine moving segments and fixed segments. However, implementation modes have been shown in which advantageously all of the segments move to produce a beam without discontinuity and with high overall light intensity, without switching off one or other of the sources.

[0047] Lines 3(b) to 3(d) of the figure 3 illustrate the creation of a zone of high lighting intensity 30 in the center of the overall light beam, in the case where the forward speed of the vehicle V is successively greater than a first determined threshold V 1 , a second determined speed threshold V 2 and a third determined speed threshold V 3 , with V 1 < V 2 < V 3 . The fact that the vehicle is traveling at high speed implies that the driver must be able to anticipate possible changes in traffic conditions, and for example obstacles that may arise in his path. It is therefore advantageous to increase the light intensity in the center of the overall light beam, by moving portions of the beam and controlling the corresponding lighting means, so that the driver has a better view of what is happening in front of his vehicle, the latter traveling in a straight line. The zone of high lighting intensity is all the more concentrated as the speed is high.

[0048] On line 3(b), a first specific global light beam 31 is formed in which the high lighting intensity zone 30 is obtained by superimposing the beam portions 1g and 1d each respectively on half of the beam portion 0. All of the microsystems, with the exception of that corresponding to the central beam portion 0, are pivoted so that the beam portions distinct from that of the center approach the center by a distance equivalent to half the beam portion width.

[0049] It can be observed that the first specific global light beam 31 is less wide than the global light beam 28. And more generally, it is notable that, the faster the speed, the less wide the global light beam. This is explained by the fact that the outer beam portions 3g and 3d follow the tightening of the beam portions on the center of the global beam, in order to keep a continuous global beam, and this is justified by the fact that at high speed, it is less penalizing not to see obstacles present on the sides at the height of the vehicle since the speed allows them to be overtaken on the momentum of the vehicle.

[0050] On line 3(c), the illumination intensity of the zone 30 is further increased by superimposing the beam portions. A band 32 of very high intensity is produced by superimposing the beam portions 1g, 1d and 0. At least three beam portions are superimposed to form this band 32. Here again, the beam portions are brought closer to the center to maintain an overall light beam without discontinuity. It can be seen that, as a result, the width of the zone of high illumination intensity, that is to say, the illumination intensity of which is greater than that of each of the portions of the overall light beam illustrated on line 3a, is greater at this stage, with V greater than V 2 , than the width of the high intensity zone when V is less than V 2 .

[0051] Finally, on line 3(d), the lighting intensity of zone 30 is increased to its maximum, again creating a band 32 of very high intensity obtained this time by superimposing at least four portions of light beam. The remarks made in the previous paragraph also apply when V is greater than V 3 . It is understood that four distinct stages have been represented here, with three determined speed thresholds to which the speed V of the vehicle is compared, but that this number could vary in particular depending on the number of segment portions.

[0052] There figure 4 illustrates a state in which a bend has been detected and in which an attempt is made to create a second specific global light beam 34 comprising a second zone of high lighting intensity 36 different from the first zone of high lighting intensity 30. This second zone is of high lighting intensity, since the speed of the vehicle V is greater than the first threshold V 1 , and it is oriented towards the inside of the bend in order to optimize the driver's visibility of the road scene in front of the vehicle.For this purpose, the first intermediate beam 24 and the second intermediate beam undergo movements, by controlling the lighting means, different from the previous case in that the central beam portion 0 is shifted towards the inside of the bend and in that that of the beam portions which is immediately adjacent to this central beam portion in the overall light beam and which is towards the inside of the face, that is to say here the portion 1d, remains unchanged. The target zone in which this second zone of high lighting intensity is to be brought to bear is determined by the vehicle control means as a function of the characteristics of the bend.

[0053] When the turning situation is over, it is then quick to return to a high-speed straight-ahead lighting situation, with a high-intensity lighting zone 30 in the center of a beam similar to the first specific overall light beam 31 (see line 4(c)). It is understood that according to the invention, one passes from one situation to the other, with a high-intensity lighting zone located in the center of the overall beam in a straight line or towards the inside of the turn, with fixed light sources in a fixed module, only by tilting a pivoting mirror.

[0054] There figure 5illustrates a state in which a vehicle has been detected and in which an attempt is made to create a third specific global light beam 38 in which a target zone, of lesser illumination, 40 is formed in which no potentially dazzling light ray is formed. For this purpose, the first intermediate beam 24 and the second intermediate beam 26 are modified by transverse shifting of at least one light segment, so as to create high intensity zones 30a and 30b on either side of the target zone 40. As previously, since the speed of the vehicle is greater than a first determined threshold V 1 , the width of the beam is narrowed by bringing the outer beam portions closer to the center.The fact, by controlling the lighting means, of moving away from the target zone, where less lighting is desired, the beam portions corresponding to this target zone, combined with this bringing closer to the center of the external beam portions, generates a superposition of beam portions on either side of the less lighting zone and therefore the splitting of the high lighting intensity zone 30 into two parts, not necessarily symmetrical, on either side of the less lighting zone 40.

[0055] As before, when the crossing situation is over, it is then quick to return to a high-speed straight-ahead lighting situation, with a high-intensity lighting zone 30 in the center of a beam similar to the first specific overall light beam (see line 5(c)). It is understood that according to the invention, one passes from one situation to the other, with a high-intensity lighting zone located in the center of the overall beam in a straight line or towards the inside of the bend, with fixed light sources in a fixed module, only by tilting a pivoting mirror.

[0056] According to a variant of the invention, it may be provided, in particular in the case of "pixel lighting", that the displacement of the beam portions as a function of the speed may be horizontal or vertical. As described above, the horizontal displacement of a beam portion is carried out on each segment individually, and it is interesting to note that the vertical displacement is carried out on the module as a whole. For this purpose, electromechanical microsystems controllable on two perpendicular axes may be used. With such devices, the light from the area to be extinguished may be "ejected" both laterally, which is preferable for areas near the horizon, and vertically, upwards or downwards, which may be more advantageous for areas located at height.

[0057] The foregoing description clearly explains how the invention makes it possible to achieve the objectives it has set itself and in particular to propose a method for controlling intermediate light beams which allows the production of a segmented complementary road type beam, which can be modified so that, depending on the instantaneous speed of the vehicle relative to at least one predetermined speed threshold, a part of the overall light beam is concentrated to form a zone of high lighting intensity, that is to say an area lit more strongly than the immediately neighboring areas, and this without loss of overall light intensity, and without increase in intensity of one or other of the light sources.

Claims

1. Method for controlling an overall light beam (28) emitted by a motor vehicle headlight and formed of beam portions (23) able to be activated selectively and produced independently of one another by illumination means (4, 6) borne by said headlight, all of the portions forming an overall light beam when they are all activated and arranged successively side by side, wherein the instantaneous speed of the vehicle is compared to a first predetermined speed threshold (V1), wherein a high-intensity illumination zone (30) to be produced is determined when the instantaneous speed is greater than the first predetermined speed threshold, wherein detection means are used to identify which of said illumination means (4, 6) produce the beam portions (23) suitable for illuminating said high-intensity illumination zone (30), and wherein a movement of said illumination means, identified in the preceding step, and of the illumination means directly adjacent to said illumination means, identified in the preceding step, is driven so as to create a first specific overall light beam (31) comprising said high-intensity illumination zone (30), said illumination means being moved so as to bring about an at least partial superposition of the beam portions produced by these identified illumination means, in the high-intensity illumination zone, wherein all of said illumination means (4, 6) are kept switched on and wherein all of the beam portions (23) are moved so as to maintain switching-on continuity on either side of the high-intensity illumination zone (30), wherein the orientation of the movement of the vehicle is detected, and wherein, when a straight-line driving situation is detected, said high-intensity illumination zone (30) is positioned, by superposing beam portions, substantially in the centre of the first specific overall light beam (31), wherein detection is carried out, on a road scene in the vicinity of the vehicle, with regard to a specific situation in which a third-party vehicle is liable to be dazzled by said overall light beam (28), and a target zone is determined in said overall beam including said third-party vehicle, characterized in that illumination means (4, 6) borne by said headlight that produce the beam portions that illuminate said target zone are then identified, and wherein a movement of said illumination means identified in the preceding step is driven so as to create a less illuminated zone (40) corresponding to said target zone, said high-intensity illumination zone (30) then being divided into two sub-zones (30a, 30b) that are positioned on either side of said less illuminated zone (40).

2. Control method according to one of the preceding claims, wherein the instantaneous speed of the vehicle is compared to at least one second predetermined speed threshold (V2), having a value greater than the value of said first speed threshold (V1), and wherein, when the instantaneous speed is greater than said second speed threshold (V2), the light intensity of said high-intensity illumination zone (30) is increased by superposing other beam portions and by concentrating the overall light beam.

3. Control method according to either of Claims 1 and 2, wherein detection is carried out, on a road scene in the vicinity of the vehicle, with regard to a specific situation in which the vehicle is confronted with a bend, and a second target zone is determined in said overall beam on the basis of the characteristics of the bend, wherein illumination means (4, 6) borne by said headlight that produce the beam portions that illuminate said second target zone are then identified, and wherein a movement of said illumination means identified in the preceding step is driven so as to create a second high-intensity illumination zone (36) corresponding to said second target zone.

4. Control method according to one of the preceding claims, characterized in that the illumination means (4, 6) are driven, when it is detected that said specific situation has ended, so as to respectively adopt a position able to create said first specific overall light beam (31).

5. Control method according to one of the preceding claims, characterized in that said illumination means comprise light sources (4) and optical deflection means (6) associated respectively with at least one of the light sources, each light source being controlled individually in terms of being switched on, while said optical deflection means are controlled individually in terms of movement.

6. Method according to one of the preceding claims, wherein the beam portions (23) consist of vertical segments that are juxtaposed with one another, the movement of the illumination means (4, 6) generating the movement of at least one of said segments and its superposition on other segments of the overall light beam.

7. Motor vehicle lighting system comprising a left-hand headlight and a right-hand headlight, each comprising at least one lighting module for implementing the control method according to one of the preceding claims, which at least one lighting module comprises a light source (4) and optical deflection means (6) mounted so as to be able to move.

8. Motor vehicle lighting system according to Claim 7, characterized in that it furthermore comprises an optical system (8) for emitting a light beam, the optical deflection means (6) being interposed between the light source and the optical system.

9. Motor vehicle lighting system according to either of Claims 7 and 8, characterized in that the optical deflection means (6) consist of optical microelectromechanical systems (14, 16) mounted so as to be able to rotate between two end positions.

10. Motor vehicle lighting system according to one of Claims 7 to 9, furthermore comprising at least means for detecting the instantaneous speed of the vehicle, means for analysing received detection information and computing means, comprising at least means for comparing the instantaneous speed with at least one predetermined threshold, in order to give a command instruction to move the optical deflection means (6).