FR3135232A1 - Light device for projecting an image on the ground - Google Patents

Abstract

Light device for projecting an image on the ground Light device (2) for an automobile vehicle (1), the light device comprising a light source (4) and a mask (5), the mask (5) comprising an opaque zone (8 ) and a first transparent zone (9, 91), the mask being movable between a primary position and a secondary position, the mask being configured to modify the light beam (F) coming from the light source so that the device light projects a first image (I1) comprising a pattern on the ground (3) when the mask is in its primary position, and so that the light device projects a second image (I2) of the pattern at the front of the vehicle when the mask is in its secondary position, the position and/or orientation of the pattern of the first image being different from the position and/or orientation of the pattern of the second image. Figure for abstract: figure 14

Description

Light device for projecting an image on the ground Technical field of the invention

The invention relates to a lighting device for a motor vehicle, the lighting device being configured to project an image comprising a pattern on the ground at the front of the vehicle. The invention also relates to a method of operating such a light device.

State of the prior art

Some motor vehicles are equipped with a light device configured to project an image on the ground in front of the vehicle. These images may include patterns such as arrows, lines or pictograms. Such light devices aim to display useful information to the driver and/or other road users. Publication EP3401161A2 discloses such a light device.

Light devices known from the state of the art are generally complex to manufacture and use. In addition, the pattern of the image projected on the front of the vehicle is sometimes incorrectly positioned or poorly oriented on the traffic lane, in particular when the traffic lane draws a curve. Bad positioning and/or bad orientation of the image pattern on the traffic lane can mislead the driver of the vehicle, or even be prohibited by certain automotive standards.

Presentation of the invention

The aim of the invention is to provide a light device and a method of operating such a light device remedying the above drawbacks and improving the light devices and operating methods known from the prior art.

More precisely, a first object of the invention is a light device that is simple to manufacture and capable of projecting an image comprising a pattern whose position and/or orientation can be adapted.

A second object of the invention is a method of operating such a light device making it possible to project an image comprising a well-positioned and well-oriented pattern on a traffic lane in all circumstances, in particular when the latter describes a curve.

The invention relates to a lighting device for a motor vehicle, the lighting device comprising a light source and a mask, the mask comprising an opaque zone and a first transparent zone, the mask being movable between a primary position and at least one secondary position, the light device being configured
- so that a light beam coming from the light source passes through the first transparent zone when the mask is in its primary position, the first transparent zone being configured to modify the light beam coming from the light source in such a manner that the light device projects a first image comprising a pattern on the ground at the front of the vehicle when the mask is in its primary position, and
- so as to project a second image on the ground at the front of the vehicle when the mask is in its at least one secondary position, the second image comprising said pattern, said pattern having a different position on the first image and on the second image and/or a different orientation on the first image and on the second image.

The at least one secondary position may comprise a first secondary position, the light device being configured so that the light beam coming from the light source passes through the first transparent zone when the mask is in its first secondary position.

In particular, the first transparent zone is configured to modify the light beam coming from the light source so that the light device projects the second image comprising said pattern on the ground at the front of the vehicle when the mask is in its position. first secondary position.

In particular, the position and/or orientation of the first transparent zone relative to the light source when the mask is in its primary position is different from the position and/or orientation of the first transparent zone relative to the light source when the mask is in its first secondary position.

The mask may comprise a second transparent zone distinct from the first transparent zone, the shape of the first transparent zone being identical to the shape of the second transparent zone, and the at least one secondary position may comprise a second secondary position, the position and/or the orientation of the first transparent zone relative to the light source when the mask is in its primary position being different from the position and/or orientation of the second transparent zone relative to the light source when the mask is in its second secondary position, the light device being configured so that the light beam coming from the light source passes through the second transparent zone when the mask is in its second secondary position.

In particular, the second transparent zone is configured to modify the light beam coming from the light source so that the light device projects the second image comprising said pattern on the ground at the front of the vehicle when the mask is in its position. second secondary position.

The mask may comprise a third transparent zone distinct from the first transparent zone, the shape of the first transparent zone being different from the shape of the third transparent zone, the mask being movable between its primary position and at least one tertiary position, the at least one tertiary position being distinct from the primary position and from the at least one secondary position, the light device being configured so that the light beam coming from the light source passes through the third transparent zone when the mask is in its tertiary position.

In particular, the third transparent zone is configured to modify the light beam coming from the light source so that the light device projects a third image comprising an additional pattern on the ground at the front of the vehicle when the mask is in its tertiary position. The additional pattern is distinct from said pattern. In particular, the shape of the additional pattern is different from the shape of said pattern. The position of the additional pattern may be identical or different from the position of said pattern, and/or the orientation of the additional pattern may be identical or different from the orientation of said pattern.

The mask can be movable in rotation between its primary position and its at least one secondary position.
If necessary, the mask can be movable in rotation between its primary position and its tertiary position.

The mask may comprise the shape of a disk or a portion of a disk.

The light device may include an optical guide arranged between the light source and a portion of the mask.

The light device may comprise a first light source, a second light source, a first optical guide arranged between the first light source and a first portion of the mask, and a second optical guide arranged between the second light source and a second portion of the mask, the second portion being distinct from the first portion and adjacent to the first portion.

The invention also relates to a method of operating a lighting device as defined above, the operating method comprising:
- the projection of a first image comprising a pattern on the ground at the front of the vehicle, the mask being in its primary position, then
- the detection of a change in the environment of the vehicle, in particular the detection of a curvature of a traffic lane on which the vehicle is traveling and/or the detection of a variation in speed of the vehicle and/or the detection of an obstacle or another vehicle in front of said vehicle, then
- moving the mask from its primary position to its at least one secondary position, then
- the projection of a second image comprising said pattern on the ground at the front of the vehicle, the position and/or orientation of the pattern of the first image being different from the position and/or orientation of the pattern of the second image.

Detecting a change in the environment of the vehicle may include detecting a curvature of a traffic lane on which the vehicle is traveling, and the pattern of the second image may be oriented substantially in the direction of the curvature of the vehicle. the traffic lane.

The method may also include the detection of a change in the environment of the vehicle, and the projection of a third image comprising an additional pattern, in particular distinct from said pattern.

By changing the image projected on the ground and the pattern included in the projected image, it is possible to adapt the information transmitted to other road users.

Presentation of figures

These objects, characteristics and advantages of the present invention will be explained in detail in the following description of different particular embodiments made on a non-limiting basis in relation to the attached figures among which:

There is a schematic view of a motor vehicle equipped with a lighting device according to one embodiment of the invention.

There is a schematic view of a mask according to a first embodiment of the invention, the mask being in a primary position.

There is a schematic view of a traffic lane on which an image is projected with a light device equipped with the mask according to the first embodiment, the mask being in its primary position.

There is a schematic view of the mask according to the first embodiment, the mask being in a first secondary position.

There is a schematic view of a traffic lane on which an image is projected with a light device equipped with the mask according to the first embodiment, the mask being in the first secondary position.

There is a schematic view of a mask according to a second embodiment of the invention, the mask being in a primary position.

There is a schematic view of a traffic lane on which an image is projected with a light device equipped with the mask according to the second embodiment, the mask being in its primary position.

There is a schematic view of the mask according to the second embodiment, the mask being in a second secondary position.

There is a schematic view of a traffic lane on which an image is projected with a light device equipped with the mask according to the second embodiment, the mask being in a second secondary position.

There is a schematic view of a mask according to a third embodiment of the invention, the mask being in a primary position.

There is a schematic view of a traffic lane on which an image is projected with a light device equipped with the mask according to the third embodiment, the mask being in its primary position.

There is a schematic view of the mask according to the third embodiment, the mask being in a secondary position.

There is a schematic view of a traffic lane on which an image is projected with a light device equipped with the mask according to the third embodiment, the mask being in a secondary position.

There is a schematic view of a mask according to a fourth embodiment of the invention, the mask being in a primary position.

There is a schematic view of a traffic lane on which an image is projected with a light device equipped with the mask according to the fourth embodiment, the mask being in its primary position.

There is a schematic view of the mask according to the fourth embodiment, the mask being in a ternary position.

There is a schematic view of a traffic lane on which an image is projected with a light device equipped with the mask according to the fourth embodiment, the mask being in a ternary position.

There is a schematic view of a mask according to a fifth embodiment of the invention.

There is a schematic view of a mask according to a sixth embodiment of the invention.

There is a partial schematic view of the light device of the .

There is a partial schematic view of the lighting device according to an alternative embodiment of the invention.

detailed description

There schematically illustrates a motor vehicle 1 according to one embodiment of the invention. The vehicle 1 can for example be a private vehicle, a utility vehicle, a truck or even a bus. The vehicle 1 comprises a lighting device 2 according to one embodiment of the invention. The light device 2 is configured to project an image on the ground 3, at the front of the vehicle 1. It is specified that the front designates the side of the vehicle 1 towards which it is heading in a straight line, in forward motion. The image can, for example, be projected a few meters or a few tens of meters in front of the vehicle. The light device 2 can be, for example, arranged at the front of the vehicle, at the level of a grille and/or at the level of projectors intended to illuminate the road and make the vehicle clearly visible to other road users. .

The light device 2 comprises at least one light source 4 capable of producing a light beam F and a mask 5 positioned on the trajectory of the light beam. The mask 5 is configured to modify the light beam coming from the light source 4 so as to project an image comprising a pattern on the ground 3 at the front of a vehicle. In particular, the mask 5 is configured to intercept certain light rays coming from the light source 4 so as to produce an image. The light device 2 is not intended to produce night lighting of the environment of the vehicle or to make the vehicle clearly visible to other road users.

The light source 4 can for example be a light-emitting diode or a set of light-emitting diodes. Alternatively, it could take any other form, such as for example an incandescent lamp. Advantageously, the light source can have sufficient power to project an image on the ground which is visible even in broad daylight. Preferably, the light source can project white light rays. The light source 4 can be connected to a printed circuit board 6. The printed circuit board can be held by a support 7 possibly comprising a heat sink.

The mask 5 is a screen extending in a plane substantially perpendicular to the light beam. The surface of the mask 5 comprises opaque zones 8 and transparent zones 9 (visible in Figures 2 and following). The opaque zones 8 are zones blocking or reflecting the light rays coming from the light source 4. They can be, for example, black or chrome in color. The transparent zones 9 are zones allowing the light rays coming from the light source 4 to pass through. The opaque zones 8 and the transparent zones 9 are complementary zones of the surface of the mask 5. For example, the mask 5 may comprise a support transparent, for example made of glass, locally covered by an occulting substrate deposited by lithography. Lithography advantageously makes it possible to obtain great geometric precision of transparent zones and opaque zones. Alternatively, other processes could be considered, such as for example cutting openings in a support made of opaque material, in particular by laser cutting.

The light device 2 also comprises an optical guide 10 arranged between the light source 4 and a portion of the mask 5. The optical guide, or light guide, is configured to guide the light rays coming from the light source 4 towards a portion of the mask 5. An optical element 11, such as a projection lens can be provided downstream of the mask 5, that is to say on the other side of the mask 5 relative to the light source 4, in order to to shape and direct the light beam towards the ground 3.

The mask 5 is movable between a primary position and at least one secondary position, distinct from the primary position. For this purpose, the light device 2 comprises an actuation means 12 in mechanical connection with the mask 5. Advantageously, the plane in which the mask 5 extends in its primary position can be identical to the plane in which it extends in its at least one secondary position. In particular, the mask 5 can be movable in rotation around an axis perpendicular to the plane in which it extends. Alternatively or in combination, the mask 5 could also be movable in translation in the plane in which it extends. Note that the actuation means 12 only moves the mask 5. The latter being very light, the actuation means 12 can be particularly simple and compact.

According to a preferred embodiment, the mask 5 is movable in rotation around an axis perpendicular to the plane in which it extends. In particular, the actuating means 12 is an electric motor. The electric motor is positioned behind the printed circuit board 6 and behind the support 7. It comprises a rotating shaft 13 passing through an opening 14 provided in the printed circuit board 6 and in the support 7. The mask 5 is fixed to the rotating shaft 13. The rotating shaft 13 can extend substantially horizontally, parallel to a longitudinal axis vehicle.

According to a variant embodiment, the connection between the actuation means 12 and the mask 5 could be arranged differently. For example, the mask 5 could be rotatably or slidingly mounted on a support separate from the actuation means 12. The actuation means could be mechanically connected to an edge of the mask 5. A translational and/or rotational movement of the mask 5 could be obtained thanks to the cooperation of a toothed wheel secured to the actuation means and a rack secured to the mask 5.

There illustrates a first embodiment of the mask 5. The mask 5 has the shape of a disk and is movable in rotation around an axis passing through the center O of the disk. Such an embodiment has the advantage that the volume occupied by the mask 5 does not vary depending on its position. The light device 2 can therefore remain very compact. The diameter of the disc can be, for example, between 1cm and 5cm inclusive. The transparent zone 9 is represented in black and the opaque zone 8 is represented in white. The outer contour of the light beams F coming from the light source 4 is represented by a dotted line. In this case, the outer contour of the light beams F has a circular shape. Alternatively, it could comprise any other shape, such as for example a generally polygonal shape, in particular a generally trapezoidal or pseudo-trapezoidal shape, the optical guide 10 then being adapted accordingly.

The transparent zone 9 has a shape, in particular a contour, suitable for the projection of an image comprising a pattern on the ground at the front of the vehicle 1. The contours of the transparent zone 9 are therefore linked to the contours of the pattern. As illustrated in the , the pattern of the image projected on the ground is a V-shaped arrow pointing substantially in the direction in which the vehicle is progressing. On the the transparent zone 9 has been schematically represented with the same V shape. In practice, the shape of the transparent zone 9 can be adapted to take into account the geometric deformations linked to the projection of the light beam on the ground 3, in particular for take into account the angle of incidence of light rays on the ground. Alternatively, any other geometric pattern, symbol, or pictogram could be considered. The largest dimension of the transparent zone can for example be between 1mm and 10mm inclusive. The geometric pattern preferably has a simple geometric shape. There shows for example other possible realizations of this pattern. As a note, the image projected by the light device is non-pixelated.

When the light source 4 emits a light beam, it is first guided by the optical guide 10 and illuminates a portion of the mask 5. The light rays incident at the opaque zones 8 of the mask are reflected or absorbed and do not are not projected onto the ground 3. The light rays incident at the transparent zone 9 of the mask pass through the mask and are then guided towards the ground by the optical element 11. As illustrated in the , we thus obtain the projection of a first image I1 comprising a pattern at the front of the vehicle. The pattern of this first image I1 is positioned and oriented substantially on the longitudinal axis X of the vehicle. This first image is particularly suitable for indicating a straight line direction of the traffic lane.

Then, for example if we detect a curvature of the traffic lane on which the vehicle is traveling, we move the mask from its primary position (illustrated in the ) to a first secondary position (shown on the ). In particular, the mask 5 is rotated around its center 0 by an angle A1 equal to a few degrees or a few tens of degrees in the clockwise or counterclockwise direction. The light source 4, the optical guide 10 and the optical element 11 remain stationary. The position of the transparent zone 9 relative to the light source 4 is therefore modified, which results in a movement and/or reorientation of the pattern on the ground. As illustrated on the , we thus obtain the projection of a second image I2 comprising the pattern at the front of the vehicle 1. The position and/or orientation on the ground of the pattern of the second image I2 is different from the position and/or of the orientation of the pattern of the first image I1. In particular, the pattern of this second image I2 is offset on one side relative to the longitudinal axis X of the vehicle and/or inclined relative to the longitudinal axis of the vehicle. This second image is particularly suitable for indicating a curved line direction of the traffic lane. According to this first embodiment, the first image and the second image are obtained by the passage of the light beam through the same transparent zone 9.

By adapting the amplitude of the rotation of the mask around the center O, we can obtain a more or less offset and/or more or less inclined position of the pattern of the second image relative to the pattern of the first image. Any intermediate position of the mask 5 between those illustrated in Figures 2 and 4 is of course possible. In certain cases, a change in the orientation of the pattern projected on the ground is necessarily accompanied by a change in the position of this pattern. It is possible to control the relationship between the variation of the inclination of the image pattern and the variation of the position of the image pattern by adjusting the dimensioning of the mask, and in particular of the transparent zone 9. In particular, the distance separating the transparent zone 9 from the center O around which the mask pivots can be adjusted for this purpose.

Advantageously, the movement of the mask 5 between its different positions can be controlled by an electronic control unit of the light device 2, having information relating to a modification of the environment of the vehicle. Such a modification of the environment of the vehicle can be, for example, a detection of a curvature of the traffic lane on which the vehicle 1 is traveling, and/or the detection of a variation in speed of the vehicle 1, and/ or the detection of an obstacle or another vehicle in front of the vehicle 1. A change in the environment of the vehicle can be detected by an environment detection means such as a camera, radar or a lidar. Alternatively or in addition, the curvature of the traffic lane on which the vehicle 1 travels can also be determined by calculating an angle formed by a steering wheel or a steering column of the vehicle.

As a note, according to the first embodiment, the mask 5 comprises a single transparent zone 9. The portion of the mask illuminated by the light source 4 can thus substantially correspond to the entire surface of the mask 4. We thus benefit from a large amplitude of positioning and/or inclination of the pattern on the ground. For example, the arrow drawn on the ground can be inclined approximately 90° to the left or to the right. When the mask 5 is rotated by half a turn relative to its primary position, we obtain the projection of the image of an arrow pointing towards the rear of the vehicle. This can be used to indicate to the driver that they are traveling in the wrong direction.

Figures 6 to 21 illustrate different embodiments of the invention. In order to simplify the description, we only focus on describing the differences compared to the first embodiment previously described. When possible, the same references as for the first embodiment are used. As a note, the terms "primary position", "first secondary position", "second secondary position", "third secondary position", or "fourth secondary position" used in this document are simply intended to distinguish different positions of the mask. These terms do not characterize any order relationship or any hierarchy between these different positions. For example, according to certain embodiments, the mask can be movable between a primary position and a second secondary position without this imposing the existence of a first secondary position.

Figures 6 to 9 illustrate a second embodiment in which the mask 5 comprises three distinct transparent zones 91, 92, 93. By “distinct”, we understand that the transparent zones are not in contact with each other. The transparent areas are separated from each other by an opaque area. Alternatively, the number of distinct transparent zones could be different from three, for example equal to four or more generally any number greater than or equal to two. The shape of the different transparent zones 91, 92, 93 may be identical. The light device 2 is configured so that the light beam F coming from the light source 4 passes through a first transparent zone 91 when the mask 5 is in its primary position (position illustrated in the ). The light beam F passes through a second transparent zone 92 when the mask 5 is in a second secondary position (position illustrated on the ). The light beam F passes through a third transparent zone 93 when the mask 5 is in a third secondary position (not illustrated). We designate by R1, R2 and R3 three rays of the disk forming the mask 5 and passing respectively through the center of the first transparent zone 91, the second transparent zone 92 and the third transparent zone 93. The orientation of each transparent zone 91, 92, 93 relative to the ray R1, R2, R3 which passes through its center is different for each transparent zone. In other words, the transparent zones 91, 92, 93 have identical shapes but different orientations when they are positioned in the field of the light beam F. According to the second embodiment presented the three rays R1, R2 and R3 are arranged at 90° from each other. Alternatively, this angle could be different, for example an angle equal to 360° divided by the number of distinct transparent zones.

The passage of the light beam F through the first transparent zone 91, as illustrated in , leads to the projection of a first image I1 comprising a pattern as illustrated in . The passage of the light beam through the second transparent zone 92, as illustrated in , leads to the projection of a second image I2 comprising the pattern as illustrated in . The orientation on the ground of the pattern of the second image I2 is different from the orientation of the pattern of the first image I1. The position of a center of the pattern of the first image on the ground may be substantially identical to the position of a center of the pattern of the second image. For example the center of the pattern of the first image I1 and the center of the pattern of the second image I2 can be positioned on the longitudinal axis X of the vehicle. Advantageously, the light source 4 can be turned off when the mask pivots between its primary position and its second secondary position, so as to make the rotation of the mask invisible to users.

As a note, the use of mask 5 as described for the first embodiment can very well be transposed to the second embodiment. That is to say that we can also make a slight pivot of the mask, for example by a few degrees or a few tens of degrees to modify the position of the same transparent zone in relation to the light beam. It is thus possible to obtain a different positioning and/or orientation of the image pattern on the ground with the light beam passing through the same transparent zone among the transparent zones 91, 92, 93.

According to a third embodiment illustrated in Figures 10 to 13, the three transparent zones 91, 92, 93 have the same shape and the same orientation relative to the rays R1, R2 and R3, but the center of each of these three zones is positioned at a different distance from the center O around which the mask pivots. The first transparent zone 91 is positioned at a greater distance from the center O relative to the second transparent zone 92 and the third transparent zone 93. The second transparent zone 92 is positioned at a shorter distance from the center O relative to the first zone transparent zone 91 and to the third transparent zone 93. The third transparent zone 93 is positioned at an intermediate distance from the center O, that is to say at a greater distance from the center O relative to the second transparent zone 92, and at smallest distance from the center O relative to the first transparent zone 91. Consequently, the pattern of the first image I1, obtained when the first transparent zone 91 is in the field of the light beam F, appears on the ground further from the vehicle that the pattern of the second image I2, which is obtained when the second transparent zone 92 is in the field of the light beam F. The pattern of the third image, obtained when the third transparent zone 93 is in the field of the light beam F, appears on the ground at an intermediate position between the pattern of the first image I1 and the pattern of the second image I2.

Advantageously, it is thus possible to adapt the position of the image projected on the ground as a function of the speed of the vehicle. The electronic control unit controlling the position of the mask 5 can receive information on the speed of the vehicle and control a movement of the mask as a function of speed thresholds. Alternatively, or in addition, we can also adapt the position of the pattern of the image projected on the ground depending on the detection of an obstacle or a vehicle preceding the vehicle 1. We can thus avoid projecting the image on the rear facade of another vehicle.

The third embodiment can be freely combined with the first embodiment and/or with the second embodiment. In particular, the mask 5 may comprise a plurality of transparent zones of identical shape but distinguishable from each other by the distance of their center relative to the center O and by their orientation relative to a ray passing through their center.

Figures 14 to 17 illustrate a fourth embodiment, also freely combinable with the first three embodiments. According to this embodiment, the mask comprises transparent zones 91, 92, 93 of different shapes. By way of non-limiting example, a first transparent zone 91 may have a shape adapted to the projection of an image of a simple arrow on the ground. A second transparent zone 92 may have a shape adapted to the projection of a double arrow image on the ground. A third transparent zone 93 can have a shape adapted to the projection of a snowflake image on the ground.

As explained previously, the use of the mask as described for the first embodiment can very well be transposed to the fourth embodiment. That is to say, we can make a slight pivot of the mask, for example by a few degrees or a few tens of degrees to modify the position of the same transparent zone in relation to the light beam. The mask then moves from its primary position to a first secondary position. The image of each of the patterns appearing on the mask can thus be moved and/or tilted on the ground.

As illustrated by Figures 14 and 16, the mask is also movable between its primary position and at least one tertiary position. The at least one tertiary position is distinct from the primary position and the first secondary position. The light device is configured so that the light beam coming from the light source passes through a different transparent zone when the mask is in its tertiary position compared to its primary position or its first secondary position. Distinct patterns can thus be projected onto the road, as illustrated in Figures 15 and 17. In particular, the light device projects a first image I1 when the mask 5 is in its primary position, and the light device projects a third image I3 when the mask 5 is in its tertiary position, the third image I3 comprising an additional pattern distinct from the pattern of the first image I1, that is to say that the additional pattern has a shape different from that of the pattern of the first image I1. In the example illustrated, the orientation and position of the additional pattern are identical to the orientation and position of the pattern of the first image I1, it being understood that one and/or the other of the position and the orientation of the additional pattern could be distinct from the position and/or orientation of the pattern of the first image I1.

The use of a mask as described for the second and/or the third embodiment can also be transposed to the fourth embodiment. The mask may include a set of transparent zones, some of which have an identical shape and others of which have a different shape. The mask is then movable between its primary position and a second secondary position, and between its primary position and at least one tertiary position. The at least one tertiary position is distinct from the primary position and the second secondary position. The light device is configured so that the light beam coming from the light source passes through a first transparent zone when the mask is in its primary position, through a second transparent zone when the mask is in its second secondary position, and through a third transparent zone when the mask is in its tertiary position.

For example, the mask may comprise at least four transparent zones, a first transparent zone and a second transparent zone having an identical shape but being configured so as to produce images comprising a first pattern having a different position and/or orientation. A third transparent zone and a fourth transparent zone may have an identical shape (but different from the shape of the first and the second transparent zone) and be configured so as to produce images comprising a second pattern having a position and/or a different orientation.

There illustrates a variant embodiment where the mask 5 has the shape of a disk portion. This shape makes it possible to obtain a greater distance between the center of each transparent zone 91, 92, 93 and the center O around which the mask pivots while maintaining a limited bulk of the mask. Increasing the distance between the center of each transparent zone and the center O makes it possible to obtain a lesser modification of the orientation of the pattern of the image projected on the ground when the same transparent zone is moved in the field of the light bleam. In other words, the movement of the same transparent area in the field of the light beam causes a movement of the pattern of the image projected on the ground accompanied by a smaller inclination of the pattern of this image compared to the movement of a transparent area of the same amplitude with a mask presenting a smaller distance between the center of the transparent zone and the center O.

There illustrates a variant embodiment in which the mask presents a set of transparent zones positioned side by side along a transverse axis Y. The mask is movable in both directions parallel to said transverse axis Y. The mask 5 can extend in a plane, or for example be wound around a part of a cylinder, in particular like photographic film in film. Depending on the position of the mask, a given transparent zone is positioned in the field of the light beam F. It is thus possible to select a transparent zone allowing the projection of an image comprising a pattern according to a desired position and/or orientation. The operation of the light device can thus be compared to that of a slide projector. There illustrates a mask comprising five transparent zones 91, 92, 93, 94, 95. Alternatively this number could be different. The mask can optionally be made of a flexible material and its lateral ends outside the field of the light beam F can be rolled up on themselves so as to reduce the bulk of the mask.

There illustrates an embodiment in which the light device 2 comprises a single light source 4 and a single optical guide 10 arranged between the light source 4 and the mask 5. The shape of the optical guide 5 defines a portion of the mask 5 receiving the light bleam.

There illustrates a variant embodiment in which the light device comprises several light sources and an optical guide 101, 102, 103 associated with each light source. According to the illustration in the , the light device comprises three light sources and three optical guides. Alternatively this number could be different, for example equal to four or more generally any number greater than or equal to two. A first optical guide 101 is arranged between a first light source and a first portion Z1 of the mask. A second optical guide 102 is arranged between a second light source and a second portion Z2 of the mask. A third optical guide 103 is arranged between a third light source and a third portion Z3 of the mask. The three portions Z1, Z2, Z3 are distinct and adjacent (in other words next to each other). Each of the three portions Z1, Z2, Z3 can have the shape of a generally trapezoidal portion with two opposite sides in the shape of an arc of a circle centered on the center O. Each of the three light sources can be switched on or off selectively. This alternative embodiment is certainly a little more complex than the alternative embodiment of the but advantageously allows you to vary the portion of the mask which receives a light beam. We thus have a greater amplitude of positioning of the transparent zone which makes it possible to obtain a greater amplitude of position and/or inclination of the pattern on the ground. In addition, it is also easier to avoid an edge of a transparent zone being positioned outside the light beam, which would lead to the projection of a truncated image. It is also easier to avoid the edge of a second transparent zone being illuminated at the same time as the first transparent zone. For example, taking into account the position of the mask 5 as illustrated on the , only the light sources associated with the optical guides 101 and 102 must be turned on to correctly project the image corresponding to the transparent zone 91. The light source associated with the optical guide 103 can be turned off, which makes it possible to avoid projecting on the ground an image corresponding to the lower edge of the transparent zone 92. Thus, it is possible to provide a greater number of transparent zones on the same mask. In addition, we also optimize the energy consumption of the lighting device by limiting the production of light rays as close as possible to what is strictly necessary.

Finally, thanks to the invention, we have a lighting device that is very simple to manufacture and takes up little space. This light device makes it possible to project images including a pattern on the ground in different positions and/or different inclinations. The position and/or inclination of a pattern on the ground can be easily adapted, in particular to follow the curvature of a traffic lane.

Claims (10)

Lighting device (2) for a motor vehicle (1), the lighting device comprising a light source (4), an environment detection means capable of detecting a change in the environment of the vehicle and a mask (5) , the mask (5) comprising an opaque zone (8) and a first transparent zone (9, 91), the mask being movable between a primary position and at least one secondary position, the light device being configured:
- so that a light beam (F) coming from the light source passes through the first transparent zone when the mask is in its primary position, the first transparent zone being configured to modify the light beam (F) coming from the light source so that the light device projects a first image (I1) comprising a pattern on the ground (3) in front of the vehicle (1) when the mask is in its primary position, and
- so as to project a second image (I2) on the ground at the front of the vehicle when the mask is in its at least one secondary position, the second image comprising said pattern, said pattern having a different position on the first image and on the second image and/or a different orientation on the first image and on the second image.
Light device (2) according to the preceding claim, characterized in that the at least one secondary position comprises a first secondary position, the light device being configured so that the light beam (F) coming from the light source passes through of the first transparent zone when the mask is in its first secondary position.
Light device (2) according to one of the preceding claims, characterized in that the mask comprises a second transparent zone (92) distinct from the first transparent zone (91), the shape of the first transparent zone (91) being identical to the shape of the second transparent zone (92), and in that the at least one secondary position comprises a second secondary position, the position and/or orientation of the first transparent zone relative to the light source (4) when the mask (5) is in its primary position being different from the position and/or orientation of the second transparent zone relative to the light source when the mask is in its second secondary position, the light device being configured to so that the light beam coming from the light source passes through the second transparent zone when the mask is in its second secondary position.
Light device (2) according to one of claims 2 or 3, characterized in that the mask (5) comprises a third transparent zone (93) distinct from the first transparent zone (91), the shape of the first transparent zone being different from the shape of the third transparent zone, the mask being movable between its primary position and at least one tertiary position, the at least one tertiary position being distinct from the primary position and the at least one secondary position, the device light being configured so that the light beam coming from the light source passes through the third transparent zone when the mask is in its tertiary position.
Light device (2) according to one of the preceding claims, characterized in that the mask (5) is movable in rotation between its primary position and its at least one secondary position.
Light device (2) according to one of the preceding claims, characterized in that the mask (5) comprises the shape of a disc or a portion of a disc.
Light device (2) according to one of the preceding claims, characterized in that it comprises an optical guide (10) arranged between the light source and a portion of the mask.
Light device (2) according to one of claims 1 to 6, characterized in that it comprises a first light source, a second light source, a first optical guide (101) arranged between the first light source and a first portion (Z1) of the mask, and a second optical guide (102) arranged between the second light source and a second portion (Z2) of the mask, the second portion being distinct from the first portion and adjacent to the first portion.
Method of operating a light device (2) according to one of the preceding claims, characterized in that it comprises:
- the projection of a first image (I1) comprising a pattern on the ground (3) at the front of the vehicle (1), the mask (5) being in its primary position, then
- the detection of a change in the environment of the vehicle by the environment detection means, in particular the detection of a curvature of a traffic lane on which the vehicle is traveling and/or the detection of a variation speed of the vehicle and/or the detection of an obstacle or another vehicle in front of said vehicle, then
- moving the mask from its primary position to its at least one secondary position, then
- the projection of a second image (I2) comprising said pattern on the ground at the front of the vehicle, the position and/or orientation of the pattern of the first image being different from the position and/or orientation of the pattern in the second image.
Method of operating a lighting device (2) according to the preceding claim, characterized in that the detection of a modification of the environment of the vehicle comprises the detection of a curvature of a traffic lane on which the vehicle is traveling , and in that the pattern of the second image is oriented substantially in the direction of the curvature of the traffic lane.