A system for projecting multiple light beams

Abstract

We provide a system configured to generate two beams. [Solution] The present invention relates to a system for projecting a light beam from a vehicle, comprising a first device configured to generate a first beam for performing a signaling function, and a second device configured to generate at least a second beam for projecting a pattern, wherein the first device comprises at least one refractive optical member for forming the first beam, and the second device comprises at least one optical element having a controlled pattern-generating surface configured to deflect light rays from a light source, the generating surface having local variations arranged to form a predetermined pattern in the second beam.

Description

Technical Field

[0001] The present invention relates particularly to the field of light-emitting devices for the automotive industry. In particular, it finds particularly advantageous applications in the field of generating light beams for generating signals such as indicating a change in the direction of travel of a vehicle, driving an emergency warning light, indicating a reverse situation, or indicating braking in a brake light at the rear of a vehicle.

[0002] The present invention also intends to generate one or more patterns projected onto a surface, typically a part of the ground around a vehicle.

Background Art

[0003] Informing a driver of a vehicle of a particular situation by means of signals is important for the driver of the vehicle, but is even more important for individuals located within the driver's environment, particularly pedestrians, cyclists, or drivers of neighboring vehicles. Such particular situations occur, for example, in the case of a change of direction, a dangerous situation, a reverse, or braking.

[0004] In order to improve the visual display of a change of direction, in the application entitled US Patent Application Publication No. 2017 / 151904 A1, it is proposed to coordinate the emission of a conventional signal beam of the flashing type, in particular, with the projection of a second beam for generating a pattern on the ground in order to provide further information regarding the change of direction. For this purpose, in this prior art, a complex reflection system coordinated with a light source is used to generate two beams.

[0005] A non-limiting object of the present invention is to propose a less complex alternative for generating a system configured to generate two beams of the aforementioned type.

[0006] Other objects, features, and advantages of the present invention will become apparent upon scrutiny of the following description and the accompanying drawings. It will be understood that other advantages can be incorporated.

Summary of the Invention

[0007] To achieve this objective, according to one embodiment, a vehicle light beam projection system is proposed, comprising a first device configured to generate a first beam having a signaling function, and a second device configured to generate at least a second beam for projecting a pattern onto the ground at a distance of less than 5 meters from the vehicle, preferably in an area close to the vehicle.

[0008] Advantageously, the first device includes at least one refractive optical member for shaping a first beam, and the second device includes at least one optical element having a controlled pattern-generating surface configured to deflect rays from a light source, the generating surface having local variations arranged to form a predetermined pattern in the second beam.

[0009] A controlled pattern-generating surface is a free-form surface, in contrast to specific optical surfaces typically used in the field of lighting and signaling for automated vehicles. Such surfaces are cylindrical, parabolic, elliptical, hyperbolic, or a combination of these types. A controlled pattern-generating surface creates a correlation between the object pattern on the generation surface and the target pattern projected onto the ground. For target patterns of simple shapes, such as discs, rectangles, triangles, or rhombuses, it is preferable that local variations concentrate on the generation surface to produce a well-defined contour of the target pattern, and advantageously, can form the contour of the object pattern. For extremely recessed surfaces or complex patterns with many lines, or patterns combining multiple regions (e.g., a series of rectangles), local variations will be distributed across the entire generation surface.

[0010] In particular, a unique technique based on caustic generation surfaces is used to generate pattern generation surfaces and produce desired patterns.

[0011] Caustics are known as optical phenomena. They can be observed, for example, at the bottom of a swimming pool illuminated by sunlight. There, a wavering pattern is formed where more focused lines of light combine to form a network, creating brighter areas with darker regions between the lines. These lines and dark regions are due to various fluctuations in the water surface. These fluctuations create local variations in orientation around the overall flat shape of the water surface. Thus, depending on the local variations encountered, the light rays are deflected in various ways, some forming more focused, and therefore brighter, lines toward each other, while other rays are deflected away from each other, forming darker areas. This network changes as the surface is agitated.

[0012] This arrangement provides a high degree of flexibility, as it allows for the practical realization of a second device for generating the beam that produces the pattern, also referred to here as the target pattern. This is because, for example, the generation surface can be placed on a dioptric element or on the surface of a reflector.

[0013] On the other hand, the first device includes a refractive optical element for shaping the output beam to calibrate it to a desired signal function. As is obvious, the first device may include other optical elements for preliminary or final shaping of the first beam.

[0014] The device is advantageously configured to emit two beams simultaneously.

[0015] The pattern can preferably be provided by delivering a visual information complementary to the signal function, i.e., a visual message in which logic is associated with the information as well as the first beam (for example, in addition to generating the first beam in the form of flashing light, displaying an intention to change direction on the ground).

[0016] The pattern projected by the second beam is projected onto a given surface outside the vehicle, usually the ground, but this surface, especially the surface the vehicle is moving on, is typically the road.

[0017] According to one option, the first and second patterns are shared in the sense that they share at least one common component. For example, a dioptric (this term is interpreted as synonymous with refractor) or reflective optical element may have both the lens of the first device and the generating surface of the second device. Alternatively, the light source can be shared between both devices, resulting in significant cost savings.

[0018] Furthermore, some or all of the components of the first and second devices may be separate. In this case, it is still advantageous to mount the separate components on the same support.

[0019] For example, the first device may include at least one dedicated light source, and the second device may include at least one other dedicated light source, but these sources may be held by a common support member, such as a printed circuit board. In another example, the first device may include at least one refractive or reflective optical element, and the second device may include at least one other refractive or reflective optical element, but these optical elements may be held by a common support member, such as a mounting structure that secures the optical elements within a headlamp unit.

[0020] In some cases, the system according to the present invention can be made extremely small and, for example, can be fully integrated with a headlamp unit in a configuration similar to existing devices that generate only a signal beam.

[0021] Another embodiment relates to a vehicle equipped with at least one system as described above.

[0022] The objectives, aims, features, and advantages of the present invention will become more apparent from the following detailed description of an embodiment, which is illustrated by the accompanying drawings below.

Brief Description of the Drawings

[0023] [Figure 1] FIG. 1 shows, in a plan view, a road situation where a double visual display of a direction change is being executed. [Figure 2] FIG. 2 shows, in a front view, a headlamp unit equipped with the system according to the present invention in one embodiment. [Figure 3A] FIG. 3A shows a first cross-sectional view of the present embodiment taken along line A-A of FIG. 2. [Figure 3B] FIG. 3B shows a second cross-sectional view of the present embodiment taken along line B-B of FIG. 2. [Figure 4A-4D] Four alternative embodiments of the system of FIGS. 3A and 3B are shown continuously. [Figure 5A-5B] Two alternative embodiments of the system of the present invention are shown. [Figures 6A-6D] Four other alternative embodiments of the system of the present invention are shown. [Figure 7] FIG. 7 is a schematic diagram of options for forming a second beam by a course texture generation surface. [Figure 8] FIG. 8 is an enlarged view of a part of the foregoing figures. [Figure 9] FIG. 9 is a schematic diagram of another option for realizing a course texture generation surface for a second beam. [Figure 10] FIG. 10 schematically shows the propagation of a target pattern from a second device. [Figure 11] FIG. 11 schematically shows a target pattern formed from a second device. [Figure 12] FIG. 12 schematically shows an object pattern of a generation surface for generating the target pattern of the foregoing figures. [Figure 13] FIG. 13 shows another example of implementation of the system of the present invention. [Figures 14A-14F]This outlines the general process for calculating the generated surface. [Modes for carrying out the invention]

[0024] The drawings are provided as examples only and do not limit this disclosure. They are schematic conceptual diagrams intended to facilitate understanding of the invention and are not necessarily drawn to the scale of actual use.

[0025] Before commencing a detailed examination of embodiments of the present invention, the following are some optional features that may be used in combination with or as substitutes for these embodiments: - The generating surface 12 is a reflective or refractive surface extending within a given overall shape and having local variations in shape around this given overall shape, the local variations being distributed throughout the generating surface 12 to provide a relief pattern that forms an object pattern over the entire generating surface, the generating surface 12 is positioned such that the majority of the generating surface is smooth and the generating surface 12 deflects a beam of light rays having a given distribution incident on the entire generating surface 12 along different orientations according to the local variations encountered by the rays, thereby forming a deflected beam that propagates a distinguishable propagation pattern upstream of a final given optimal propagation distance and over an operating range extending at least to that extent, the propagation pattern corresponding to a distorted projection of the object pattern, the optical element is positioned such that the propagation pattern is visible from outside the light-emitting device and projected onto a target surface located within the operating range and / or at a distance (D1, D2) substantially equal to the optimal distance. - The first device and the second device each have at least one common light source 200. - The first device and the second device have at least one common optical element. - At least one common optical element includes at least one common dioptric optical element. - The system according to the present invention includes a headlamp unit 4 housing a first device and a second device, wherein at least one common dioptric optical element includes an outer lens 6 that seals the headlamp unit 4. - At least one common dioptric optical element includes the waveguide 25. - At least one common optical element includes a reflector 22. - At least one common optical element includes an optical element having a generating surface 12. - At least one common optical element includes a dioptric optical element that forms a refractive optical element for shaping the first beam 2. - The second device includes a plurality of optical elements 10, each having a generating surface 12. - The optical elements 10, each having a generating surface 12, are arranged at intervals along the common length dimension of the optical element. - The signal function can be selected from among the following: turn signal, reverse signal, brake signal, and hazard light signal. - The pattern consists of multiple parts that are spaced apart from each other.

[0026] If necessary, the system of the present invention may have any or a combination thereof of the following characteristics: - The first device includes a refractive optical element, and the second device includes another refractive optical element; these two refractive optical elements are separate and fixed to the same support, and / or adjacent to each other; - The first device includes a reflective optical element, and the second device includes another reflective optical element; these two reflective optical elements are separate and fixed to the same support, and / or adjacent to each other; - The first device includes a reflective optical element and the second device includes another refractive optical element, or the first device includes a refractive optical element and the second device includes another reflective optical element, and these two optical elements are separate and fixed to the same support; - The first and second devices include a common dioptric optical element, the latter including a first region exclusively or largely allocated to the path of a ray intended to form a first beam, and a second region exclusively or largely allocated to the path of a ray intended to form a second beam; - In the latter case, the dioptric optical element may have a cross-section that exhibits a change of direction between these two regions; - The first and second devices include optical elements in the form of a common reflector, the latter including a first region exclusively or largely allocated to the path of a ray intended to form a first beam, and a second region exclusively or largely allocated to the path of a ray intended to form a second beam; - In the latter case, the reflector may have a cross-section that indicates a change of direction between these two regions; - If necessary, the second device uses all the components of the first device, and the optical elements are components attached to the optical elements of the first device.

[0027] With respect to the generation surface, the following embodiments may be implemented if necessary: - A given distribution is such that, for any plane perpendicular to the propagation direction, at a given point on this plane, the incident light rays (r1, r2, r3) at that point arrive from a single direction; this can correspond to the distribution of a light-emitting diode; - The generation surface includes at least one smooth portion which occupies most of the generation surface (12;12'), and the transition from one local variation to another is smooth within the range of this smooth portion, and if necessary, the entire generation surface is smooth, the transition from one local variation to another is smooth, and if necessary, the transition between several local variations is formed by edges.

[0028] The terms “upstream” and “downstream” refer to the direction of light ray propagation within and outside the light-emitting device. Unless otherwise specified, the terms “forward,” “backward,” “downward,” “upward,” “sideways,” and “lateral” refer to the direction of light emission from the light-emitting device and indicate the corresponding change in direction. In the features described below, terms relating to verticality, horizontality, and transverse (or lateral direction), or similar terms, should be understood in relation to the location where the lighting system is intended to be mounted in the vehicle. In this specification, the terms “vertical” refers to a direction oriented perpendicular to the plane of the horizon (corresponding to the height of the system), and the term “horizontal” refers to a direction oriented parallel to the plane of the horizon. These should be considered under the operating conditions of the device in the vehicle. The use of these terms does not mean that slight variations in vertical and horizontal directions are excluded from the invention. For example, inclinations of the order of +10° or -10° with respect to these directions are considered in this specification to be slight variations with respect to the two preferred directions. For horizontal surfaces, the inclination is generally -5° to 4°, and for lateral surfaces, it is -6° to 7.5°.

[0029] In this invention, the target pattern forms a logo, pictogram, geometric pattern, or a series of multiple logos, pictograms, or geometric patterns, and combinations thereof, for example, a pictogram with one or more geometric patterns. Advantageously, geometric patterns of well-known shapes, such as strips, chevrons, triangles, or discs, are selected.

[0030] In the following text, the terms "first device" and "second device" do not necessarily mean that these devices are entirely separate. On the contrary, it is advantageous for some components to be shared.

[0031] The system's embodiments will be described below with particular reference to Figures 1 to 6D.

[0032] Figure 1 illustrates an example of an application of the present invention in a plan view. In the situation shown here, vehicle 1, equipped with the system of the present invention, is overtaking and returning to the right lane. In this context, the driver activates a turn signal light corresponding to a first beam 2, which conveniently has normalized photometric parameter settings. Simultaneously, the visual indication generated by the first beam 2 is complemented by the projection of a pattern 3 onto the road by the system of the present invention, positioned to the right of the front of vehicle 1.

[0033] This example is not exhaustive. In particular, it is preferable that an equivalent system be mounted on the front left side of the vehicle. The two-beam generation proposed here can also be applied to other contexts, such as pattern projection and reverse light beam, or pattern projection and brake light beam.

[0034] Figure 2 shows an example of a surface-view embodiment of a headlamp unit 4 incorporating the system of the present invention. The unit 4 can be manufactured in a conventional manner, comprising a rear section that defines the boundary of the unit 4's internal volume and an outer lens 6 that seals the surface of the unit 4. Figure 3A shows an example of the interaction between the outer lens 6 and the rear section of the unit 4 in the form of a chassis 8. In the illustration of Figure 2, the unit 4 includes not only the system of the present invention but also two other light projection devices corresponding to reference numerals 5a and 5b. For example, these may be devices for providing light-emitting functions such as low-beam and / or high-beam lights.

[0035] A light-emitting module 20 is located at the top of the headlamp unit 4, and its structure can be seen more clearly in Figures 3A and 3B. In this example, the light-emitting module 20 extends longitudinally along the width dimension of the unit 4. This allows for, for example, the first beam to be given an elongated and flat shape, which is typically the forward direction-changing signal beam for the vehicle.

[0036] In the cross-section shown in Figure 3A, which corresponds to plane AA of reference numeral 7 in Figure 2, the light-emitting module 20 includes a light source 200 mounted on a support, in which case the support has a flat support surface.

[0037] In ways known by itself, the present invention may use light-emitting diodes (commonly also called LEDs) as light sources. These may optionally be one or more organic LEDs. These LEDs may, in particular, have at least one chip provided using semiconductor technology and capable of emitting light. Furthermore, the expression “light source” is understood herein to mean at least one element source, such as an LED, capable of generating a luminous flux resulting in the generation of at least one light beam when the system of the present invention is output.

[0038] In this example, a ray emitted from source 100 is directed towards a reflector 22 that causes angular deflection of the ray with respect to a lens 23 capable of forming a lens that shapes a first beam. In a non-limiting form, Figure 3A shows the radiation from source 100 in the vertical mean direction and the deflection by reflector 22 that produces an outgoing beam along the horizontal axis.

[0039] As previously shown, the light-emitting module 20 may have an elongated shape, and for this reason, the reflector 22 may extend along its length. Furthermore, in order to generate light radiation distributed along the reflector 22, the light-emitting module 20 preferably includes a plurality of light sources 200 that are uniformly spaced along its length.

[0040] However, the elongated shape of the light-emitting module 20 is not essential. In particular, it may have a length dimension shorter than the width of the headlamp unit. The headlamp unit may also be equipped with multiple light-emitting modules to form multiple first and second devices.

[0041] To define the boundary of the light-emitting module 20 and block the emission of light toward the outer lens 6, an envelope surface may be formed by the masking wall 21, thereby defining the boundary of the internal volume of the light-emitting module 20.

[0042] In this example, as in the other examples below, various lensing techniques may be used to shape the first beam. In addition, multiple optical elements, in particular multiple lenses, may be used for this shaping. For example, a focusing lens or a lens with a diffraction grating, such as a Fresnel lens, may be used to give the first beam the desired shape.

[0043] Figure 3B is very similar to the one shown in the previous figure. This figure is a cross-section of reference numeral 9 taken along the BB direction in Figure 2. However, it should be noted that at this point in the longitudinal dimension of the light-emitting module 20, the outer lens 6 does not have a relief pattern. Conversely, in the cross-section of Figure 3A, the outer lens 6 has a pattern-generating surface 12, which is formed here non-limitingly on the inner surface of the outer lens 6. The dioptric elements constituting the outer lens 6 form optical elements 10 at this point on the surface 12 and generate a second beam used to form the pattern.

[0044] Figure 2 also shows that multiple surfaces 12 are formed on the outer lens 6. As is obvious, an optical element 10 is formed in each corresponding region of one of these surfaces 12, so the system includes three second devices, each forming a second beam. In this configuration, three patterns 3 can be projected. If necessary, one source 200 may be positioned facing each of the surfaces 12.

[0045] In this way, the light-emitting module 20 and the outer lens 6 are combined to form the first and second devices. These devices have many common components, including at least the light source 200, the reflector 22, and the lens 23 in this example. In this context, the optical element 10 can be used to reshape a portion of the beam emitted from the lens 23 to locally generate a second beam, the first beam being generated when light exits the outer lens 6 outside the surface occupied by the element 10.

[0046] Figures 4A to 4D propose alternative configurations for the light-emitting module 20. As before, the light-emitting module 20 includes a masking wall 21. The lens 23 forms the exit diopter of the light-emitting module 20. However, the components for generating the light rays that pass through the lens 23 are different.

[0047] In the case of Figure 4A, these components include a waveguide 25. Similar to the reflector 22 described above, the waveguide 25 has a longitudinal dimension that extends along the length dimension of the light-emitting module 20. In particular, the waveguide 25 may take the form of a rod, preferably with a circular cross-section. In the present example, the waveguide 25 has an exit surface 251 formed by a notch that continues along the longitudinal dimension of the waveguide 25, is located opposite a diopter for the exit of the light rays from the waveguide 25, and acts as an obstacle to the internal total internal reflection of the light from the waveguide 25, in order to generate the light output from the waveguide 25 toward the lens 23 substantially along its length.

[0048] In this context, at least one light source 200 (not visible in Figure 4A) is attached to the system, and advantageously, preferably, is positioned at one of the ends of the conduit 25 in an average illumination direction extending along the longitudinal length of the conduit 25. Optionally, to improve the distribution of light output, another light source 200 is advantageously attached to the other end of the conduit 25 in a similar manner.

[0049] In this example, a support 24 may be used to fix the conduit 25 and, optionally, the light source.

[0050] The exit diopter of the waveguide 25 may form or contribute to the formation of the first beam, but in this example, the lens 23 is retained. This case is not limiting. Furthermore, in the variant shown in Figure 4C, the lens 23 is omitted. In this case, the waveguide 25 may be used to form the first beam and / or the corresponding portion of the outer lens 6.

[0051] Another shape of the waveguide 25 in the option without lens 23 is shown in Figure 4B. Here, the waveguide 25 has a flat shape. This shape is related to the fact that there is at least one light source 200. The surface for injecting light into the waveguide 25 can be formed by a connecting cavity 252. Multiple sources 200 may be spaced apart along the longitudinal dimension of the light-emitting module 20, as in Figures 3A and 3B.

[0052] When light is received by the conduit 25, it undergoes total internal reflection along the rear cross-section toward the exit surface of the conduit. Reflecting surfaces 153, which are inclined with respect to the upper and lower surfaces of the conduit 25, in opposing cross-sections of the conduit 25, deflect at least a portion of the light toward the exit.

[0053] The options in Figure 4D are quite similar, but this light-emitting module 20 is equipped with a lens 23.

[0054] From the above, it is clear that the refractive optical member of the first device for shaping the first beam may be generated in various ways, in particular, in at least one of the waveguide, lens 23, and sealing outer lens 6 of the headlamp unit 4.

[0055] Furthermore, in these examples, it may be sufficient to locally modify the design of the outer lens 6 to form a second device that generates a second beam, because the pattern generation surface 12 can be placed on the outer lens 6.

[0056] However, these pattern generation surfaces 12 may be implemented at other locations.

[0057] In particular, Figure 5A shows an alternative configuration in which the light-emitting module 20 incorporates one or more generating surfaces 12 on the lens 23. In the configuration of Figure 5A, similar to the configuration of Figure 3A, at least one light source 200 emits a ray of light toward the reflector 22. The reflector may have a length dimension aligned with the width of the headlamp unit, as in the case of the reflector in Figure 2. However, a shorter reflector is also possible.

[0058] The reflector includes a first portion 221 in the area of ​​the lens 23 where the pattern generation surface 12 is located, which deflects some of the light rays in a first mean direction, and these rays, after being further shaped, play a role in forming a first beam. For example, the first portion 221 has a concave curved contour.

[0059] The reflector 22 has a second portion 222 located on the lower extension of the first portion 221, the second portion 222 mainly serving the function of mechanical support.

[0060] Advantageously, the reflector 22 includes a single component in which two parts 221 and 222 are continuous with each other in cross-section, preferably manufactured as a single unit.

[0061] According to alternatives not shown, parts 221 and 222 can be fabricated from two separate parts. In this case, it is advantageous to mount them on a common support.

[0062] If the length dimension of the reflector is greater than the corresponding dimension of the generating surface 12, it is preferable that the reflector 22 includes only the first portion 221, since only the generation of the first beam is required there.

[0063] Returning to Figure 5A, the path of the light ray after the reflector 22 passes through the lens 23. The first portion 231 of the lens 23 can be used to optically process the light ray intended to form the first beam, thereby forming the refractive optical member of the first device. As before, this shaping may depend on the intended signal function.

[0064] The lens 23 further includes a second portion 232 positioned on the path of a ray intended to form a second beam, in a region including at least the generating surface 12. Preferably, the generating surface 12 is positioned on one of the surfaces of the second portion 232. The optical element 10 is then generated at this position. Most, or all, of the ray forming the second beam is directly irradiated from the light source 200, but some of it may be generated by reflection from the surface 222.

[0065] As in the case shown in Figure 2, in order to provide a surface 12 on the outer lens 6, the generating surface 12 may cover only one or more local portions of the lens 23, rather than its entire length, as proposed in Figure 2. The second beam is generated only when light passes through the generating surface 12, and the remainder of this light may or may not contribute to forming the first beam, or it may be lost due to an obstacle such as a mask.

[0066] As an alternative to the representation shown in Figure 5A, parts 231 and 232 are not essential for forming a single, integrally manufactured lens 23. In particular, they may be formed as separate parts, in which case it is advantageous to attach them to the same support.

[0067] Preferably, the first and second portions 231 and 232 do not have collinear contours, in which case they have angles such that the rays have different orientations, as shown in Figure 5A.

[0068] Figure 5B shows an alternative configuration similar to the above, which preferably includes two light sources 200 arranged on the same support and spaced apart along a direction perpendicular to the longitudinal direction of the light-emitting module.

[0069] In this way, the two sources 200 in question are placed side by side, one behind the light-emitting module 20 and the other further forward. As is obvious, such pairs of sources 200 may be repeatedly arranged along the longitudinal dimension of the light-emitting module 20. In this manner, three or more sources 200 can also be placed side by side. Such a solution results in a more precise distribution of light for forming the first and second beams. This is because one of the sources 200 can generate most of the light for forming the first beam, while the second source 200 can generate most of the light for forming the second beam.

[0070] Other embodiments can be seen in Figures 6A to 6D.

[0071] Therefore, in the four illustrated cases, the optical element 10 is generated by forming a generated surface 12 on the reflector 22.

[0072] In the case of Figure 6A, the operation is quite similar to that illustrated in Figure 5A, for example. At least one light source 200 illuminates a reflector 22, which is configured such that a portion of the light rays is directed to an exit portion to form at least a portion of a first beam, while a portion of the other light rays is directed to another exit portion to form a second beam at the location where the generating surface 12 exists. More precisely, as shown, the reflector 22 further includes a first portion 221 and a second portion 222. With regard to the feasibility of generating these portions, the aforementioned views, particularly with reference to Figures 5A and 5B, can be applied.

[0073] Similarly, the light-emitting module 20 includes a lens 23, and information regarding this can be found by referring to the information shown in Figures 5A and 5B.

[0074] However, in Figure 6A, the generation surface 12 is located on the reflector 22, more precisely on its second portion 222. Thus, in this situation, the reflective optical element 10 is generated at this location. As in the previous case, the generation surface 12 is located along the length of the reflector 22. For the local generation of the generation surface 12, or multiple generation surfaces, along the reflector 22, see Figure 2.

[0075] Figure 6B shows an alternative configuration of Figure 6A, in which a pair of sources 200 are arranged on a common support, with the average direction of irradiation from one source targeting the first portion 221, while the average direction of radiation from the other source targets the second portion 222. As before, at least a portion of the lens 23 plays a role in forming a refractive optical element for shaping the first beam.

[0076] The modified forms in Figures 6C and 6D are similar to those in Figures 6A and 6B, respectively. Briefly, the lens 23 either contains only one portion 221 from which the first beam is generated, or contains at least one aperture that forms a path 26 of light intended to form the second beam. Thus, the ray from the light source 200 for forming the second beam, after being processed by the generating surface 12, follows a path where the lens 23 is absent, along the path 26 corresponding to propagation through the air at this position.

[0077] As in the cases of Figures 5A and 5B, the illustrated arrangement can only correspond to the configuration of the light-emitting module 20 in the region where the generating surface 12 exists. Outside this region, all the light can be used for the first beam, or some may be lost as a result of masking specific areas of the lens in particular.

[0078] Although not shown, in one embodiment, the first device includes at least one source belonging to it, and the second device includes at least another source belonging to it.

[0079] Accordingly, generally speaking, the system of the present invention can take the form of a highly shared configuration, for example, by extending to share a light source, a reflector and / or a waveguide and / or at least one lens. Conversely, it can take the form of a separate configuration with respect to at least one component selected from the light source, reflector and / or waveguide and / or at least one lens. In the latter case, it is still desirable that at least some of the components of the two devices share the same support. If necessary, the first device may be configured in the form of a first light-emitting module, and the second device may be configured in the form of a second light-emitting module, both light-emitting modules mounted on a common support.

[0080] Referring particularly to Figures 7 to 14F, an example of an embodiment of an optical element in which a pattern generation surface is provided in the form of a caustics generation surface is shown below.

[0081] This is because one aspect of the present invention relates to the use of caustics to form patterns for the purpose of visual display on a projection surface such as the ground. Generally speaking, caustics is an optical phenomenon resulting from the formation of patterns that form an overall network of more concentrated lines of light, with darker gaps between them. Thus, depending on the local variations encountered, the light rays are deflected in various ways, some forming more concentrated, and therefore brighter, lines toward each other, while other rays are deflected away from each other, forming darker areas.

[0082] Such patterns can propagate and can typically have a discernible shape upstream of a given finite optimal propagation distance, and over an area of ​​effect extending at least to that extent, with the propagated pattern corresponding to a distorted projection of the object pattern. "Discernible" is interpreted as meaning that the pattern is recognized as a pattern observed at the optimal distance. Thus, projection of the pattern by a second light beam becomes practical when the pattern is discernible. The best results are observed when the target surface is located at a distance substantially equal to the optimal distance.

[0083] In this application, “smooth” is interpreted as meaning a region that is differentiable in all respects, in other words, a region without protruding or recessed edges. A region is smooth if all points forming that region conform to this definition.

[0084] Therefore, in order to generate a ray according to a given distribution, means for generating a second beam can be used, in particular, including at least one light source and a series of one or more optical elements, in which case the ray is generated such that it strikes the optical elements. Thus, by irradiating with the second light beam, it becomes possible to generate a propagation pattern, which propagates until it encounters a certain surface, in particular the target surface on which the vehicle is moving.

[0085] A target pattern is formed by projecting the propagation pattern onto the target surface.

[0086] This pattern also propagates over a finite, given distance, that is, over an operating range that includes the distance at which clarity is optimal, or the optimal propagation distance, thereby allowing a certain degree of freedom regarding the distance between the optical element and the target surface. This optimal propagation distance (hereinafter referred to as the optimal distance) is the distance at which most of the deflected rays forming the target pattern intersect with each other, and therefore, the distance at which the pattern is sharpest. Consequently, since the distance between the system of the present invention and the surface onto which the pattern is projected is usually predetermined, it is easy to design the generation surface by referring to this definition.

[0087] Figures 7 and 8 illustrate the general principle of using caustics in the present invention.

[0088] According to the present invention, the optical element 10 has a controlled caustics generating surface 12. This generating surface 12 may be a reflective surface or a refractive surface, as shown in Figures 1 and 2. This optical element is also referred to below as a caustics generator.

[0089] The generated surface 12 extends within a given overall shape 13, which is represented by vertical dashed lines in Figures 1 and 2.

[0090] More specifically, in the embodiment of Figure 7, the optical element 10 is a transparent plate having an incident surface 11 and an exit surface. The incident surface 11 is positioned facing an assembly (at least one light source, advantageously one of the solutions shown above with reference to Figures 1 to 6D) that generates an upstream beam 14 consisting of rays such as the illustrated rays r1, r2, r3. The exit surface is positioned to receive the rays r1, r2, r3 refracted by the incident surface 11.

[0091] As shown in the illustrated example, the injection surface may be formed particularly entirely by the generated surface 12.

[0092] Generally speaking, the generated surface 12 has local variations in shape around a given overall shape 13. These local variations are distributed throughout the generated surface 12, resulting in the generation of a relief that forms an object pattern across the entire generated surface 12.

[0093] For example, these localized variations form depressions and bulges on the injection surface of the caustic generator 10.

[0094] Generally speaking, these different local variations are arranged such that the majority of the generated surface 12 is smooth. Therefore, over most of the generated surface 12, the surface is differentiable at all points. In other words, this smooth portion has no protruding or recessed edges.

[0095] Generally speaking, these different local variations cause the generation surface 12 to be positioned such that, for beams of rays r1, r2, and r3 having a known and given distribution incident on the entire generation surface 12, the rays r1, r2, and r3 are deflected to different orientations according to the local variations encountered by the rays. This creates a deflected beam that propagates an emission pattern upstream of a finite given optimal propagation distance and over an area of ​​action that extends at least to that extent, and this propagation pattern corresponds to a distorted projection of an object pattern.

[0096] This generation surface 12 has local variations and corresponds to a controlled caustic generation surface.

[0097] This is because these local variations cause local convergence and diffusion of the light rays. Because these changes are local, most of the light rays either move away from each other or toward each other without crossing before a certain distance. Thus, just as the surface of a swimming pool through which sunlight passes produces an emission pattern that propagates and is projected at the bottom of the swimming pool, the generating surface 12 produces a propagated emission pattern, i.e., a propagation pattern that can be projected onto the ground.

[0098] In the case of a controlled caustics generation surface as described in the present invention, the emission pattern propagates over at least a given optimal distance, depending on local variations. Beyond this optimal distance Dp, the rays of the deflected beam intersect. Therefore, the second device that generates the second beam is positioned within a suitable distance range detailed in Figure 10, such that the surface onto which the pattern is projected is at a distance that makes the pattern identifiable.

[0099] In the context of this invention, and as can be seen in the schematic diagram of Figure 10, the optimal distance Dp is finite. If the screen is inserted at an intermediate distance D1 or another intermediate distance D2 that is shorter than the optimal distance Dp, the same pattern will be observed with some distortion.

[0100] It should be noted that this optimal distance Dp is the distance at which the pattern has the best clarity. Therefore, the generated surface can be designed by referring to this definition.

[0101] Furthermore, there may be a minimum distance D0 below which no pattern is formed. This minimum distance D0 is usually quite short. This minimum distance D0 may be a few centimeters or even a few millimeters, and is generally achievable for the intended application.

[0102] Furthermore, the pattern is not lost immediately upon ray intersection, but rather at a greater distance (not shown) afterward. However, it is easier to design the generating surface by referring to a more precisely defined ray intersection distance than to the distance at which the pattern is considered to be lost. Therefore, in this application, this ray intersection distance is referred to as the optimal propagation distance or optimal distance.

[0103] In other words, the range of action includes a downstream portion from the optimal distance Dp to this maximum distance, and an upstream portion from the minimum distance D0 to the optimal distance Dp. The pattern identifiable at the optimal distance Dp at a position on the projection surface remains identifiable within these upstream and downstream portions as well.

[0104] As a general principle in this invention, the downstream portion may have different values ​​from the upstream portion. In particular, its magnitude may be half or less.

[0105] For example, in a light-emitting module having a diffuse portion of a sealed outer lens 6 with an outer lens Dp of 20 cm and a minimum distance D0 of 1 cm, the value for the upstream portion may be 19 cm, and the value for the downstream portion may be less than 9.5 cm.

[0106] In particular, the optical element 10 and its local variations are arranged so that a propagation pattern is projected onto a target surface forming a screen, thereby forming a light-emitting pattern called a target pattern. This target surface is visible from outside the light-emitting device 1 and is located at a distance within its operating range. The target surface may be at an approximately optimal distance Dp, which improves clarity. The target surface corresponds to the surface on which the vehicle moves, particularly a part of the road.

[0107] As a general principle, for the purpose of manufacturing the generated surface 12, this surface is calculated by taking into account, in particular, the target pattern to be displayed, the shape of the target surface, and the position of the target surface with respect to the rays that form the target pattern, as well as a given distribution of rays r1, r2, and r3 when emitted by the beam generator 3, in particular the incidence of these rays onto the caustic generator 10.

[0108] According to the present invention, a given distribution may correspond to rays r1, r2, and r3 that are substantially parallel or substantially generally distributed within a radiating cone 14, such as a dispersed light source like an LED, as shown in Figures 7 to 9. This makes it easier to determine the angle of incidence of the rays to the caustics generator 10, and thus simplifies the calculation of the generation surface 12.

[0109] For this purpose, a given distribution can be considered such that, for any plane perpendicular to the propagation direction, the incident ray at a given point on this plane arrives from a single direction. This is because the distribution of light rays emitted by an LED substantially corresponds to such a given distribution.

[0110] To simplify the calculation, the surface may be discretized into a number of elemental surfaces that are considered to be similar to the points mentioned in the preceding paragraph.

[0111] The vehicle is fitted with a second device that generates a second beam by caustics in such a manner that light rays r1, r2, and r3 are incident on the generation surface 12.

[0112] In particular, it is preferable that the upstream beam 14 is radiated in a given general direction with respect to the generation surface 12.

[0113] It should be noted that these caustic generation surfaces do not require any high precision in positioning the upstream beam 14. Therefore, assembly is simplified.

[0114] The method for calculating this generated surface 12 may follow the procedure shown below, one example of which is shown in Figures 14A to 14F: In a single upstream process called E1, as illustrated in Figure 14A, while considering the given distribution of light rays r1, r2, and r3, in other words, while defining the luminosity of each point on the optical element 10 called object points p1, p2, p3, p4, and p5 in a given overall shape 13, the relationship defining the incident angles of light rays r1, r2, r3, r4, and r5 and their distributions at each point in the given overall shape 13 is determined. In a process called downstream process E2 (this process may be performed before, after, or simultaneously with the upstream process E1), the distribution of light on the target surface from which the target pattern can be obtained is defined, and thereby the luminosity of each point on the target surface 19 called target points p'1, ​​p'2, p'3, and p'4 is defined. Next, in correlation step E3 illustrated in Figure 14B, in order to obtain the luminosity required at these points to form a pattern, the relationship between each object point p1, p2, p3, p4, p5 and each target point p'1, ​​p'2, p'3, p'4 is determined, in particular, in such a way that each target point p'1, ​​p'2, p'3, p'4 that receives light is associated with only one object point p1, p2, p3, p4, p5 or with a series of these points. Next, in steps E4 / E5 of the local variation orientation, illustrated in Figures 14C to 14F, the orientation of the local variation applied to the overall shape is determined according to the target and object points associated by the relationship determined in correlation step E3. As a result, the rays r1, r2, r3, r4, and r5 incident on object points p1, p2, p3, p4, and p5 are deflected to have an orientation that allows them to reach the target points p'1, ​​p'2, p'3, and p'4 associated by this relationship.

[0115] In the upstream process E1, the distribution of light rays as they reach a given overall shape 13 is taken into consideration. The simplest case is an optical element 10 made of a transparent plate, in which the given overall shape 13 of the incident surface 11 and the generated surface 12 is flat, and which includes a beam generator 3 as in Figure 9 that emits parallel light rays.

[0116] In this simple case, the upstream beam 14 and the optical element 10 are positioned such that the light rays are perpendicular to the incident surface 11. Therefore, these light rays are not deflected before they encounter the exit surface where the generation surface is formed.

[0117] Embodiments in Figures 7 and 8 and Figures 14A to 14F represent an intermediate case in which the rays are distributed within the initial envelope cone of the beam 14, then refracted by a flat incident surface, and thus remain inscribed within the cone. This facilitates the determination of the incident angles of rays r1, r2, r3, r4, and r5 on the overall shape 13, and therefore the determination of the incident angles of rays r1, r2, r3, r4, and r5 on the generating surface 12.

[0118] The embodiment in Figure 9 is another intermediate case where the distribution of rays r1, r2, and r3 is initially simpler because the rays are parallel in the upstream beam of the optical element. However, the rays are then refracted in various ways by the incident surface 11 because the incident surface 11 is curved and is cylindrical, for example, having a circular or elliptical cross-section. However, if this curvature is defined, this definition can be used to determine the orientation of the rays r1, r2, and r3 when they reach a given overall shape 13 of the generating surface 12 (which is also curved).

[0119] In the example shown in Figure 9, the optical element is a curved transparent plate in which the predetermined overall shape 13 of the incident surface 11 and the generating surface 12 is cylindrical.

[0120] To create parallel light rays, the second device may include a light source such as a light-emitting diode and a collimating lens that can orient the light rays parallel using a diopter, as shown in Figure 9.

[0121] However, more complex cases can be considered where rays are distributed across a curved, particularly cylindrical, incident surface of a radial cone, and across a generated surface having a given curved overall shape.

[0122] Other given ray distributions can be assumed.

[0123] The simplest case for the downstream process E2 is when the target surface 19 is flat and perpendicular to the overall direction of radiation of the rays when it reaches the overall shape 13 of the calculated generated surface 12. In this case, the target pattern corresponds to the propagation pattern.

[0124] In more complex cases, the orientation of a flat target surface must be allowed, such that it is oblique to the overall direction of radiation of the light rays as they reach the generating surface. However, even then, such a decision is simple. If the target surface is not flat, its shape must be taken into account, by defining its shape by equations, in particular to determine the distribution of light, so that the target pattern can be observed during projection. In all more complex cases, the propagation pattern is different from the target pattern, if defined on a plane perpendicular to the direction of propagation of the pattern.

[0125] Next, step E3 can be performed using various methods to correlate the light rays incident on the overall shape 13 of the generation surface 12 with the distribution of light on the target surface 19.

[0126] As explained above, this correlation process makes it possible to determine which object points p1, p2, p3, p4, and p5 of the given overall shape 13 are associated with which target points p'1, ​​p'2, p'3, and p'4 of the target surface 19.

[0127] As a result of the upstream process E1, the orientation of the rays r1, r2, r3, r4, and r5 when they reach the given overall shape 13 of the generated surface 12 can be determined. By utilizing the correlation between target points p'1, ​​p'2, p'3, and p'4 and object points p1, p2, p3, p4, and p5, it is also possible to determine the orientation of the rays r1, r2, r3, r4, and r5 emanating from this given overall shape 13 in order to cause the object points p1, p2, p3, p4, and p5 to reach the correlated target points p'1, ​​p'2, p'3, and p'4.

[0128] This makes it possible to perform orientation steps E4 / E5 in all subsequent steps by calculating the variations caused by the injection surface with respect to the given overall shape 13, and thus it becomes possible to define the generated surface 12.

[0129] Once this calculation is performed, it can be confirmed that the generated surface 12 is at a distance from or close to a given overall shape 13, depending on the range of local variation. Therefore, to refine the calculation of the generated surface 12, the upstream and downstream processes, along with the definition process, can be iterated by considering the arrival and departure of rays not in relation to a given overall shape, but in relation to the previously obtained shape of the generated surface. The accuracy of this surface, and therefore the sharpness of the image, will improve as the number of iterations increases. This also allows for the smoothing of the generated surface.

[0130] To perform the orientation process, Cartesian laws, also known as Snell's Law or the Snell-Cartes Law, may be used.

[0131] Therefore, in the sub-step E4 illustrated in Figures 14C and 14E, in order to deflect each incident ray r1, r2, r3, r4, r5 when the surface reaches the corresponding refraction direction, the tangent t and normal n of a given overall shape 13 in the arrival and departure directions of the rays r1, r2, r3, r4, r5, or object points p1, p2, p3, p4, p5 of the previously calculated generated surface, can be determined.

[0132] By determining the set of normals n, also called the normal field, the generated surface 12 having these normals is determined in sub-step E5 shown in Figures 14D and 14F.

[0133] Figures 14C and 14D illustrate the execution of these two sub-processes in detail at object points p1, p2, and p3, respectively, with their reference numbers omitted from Figures 14C and 14D for clarity.

[0134] Figures 14E and 14F illustrate the execution of these two sub-processes in magnified view at object points p4 and p5, with their reference numbers omitted from Figures 14E and 14F for clarity.

[0135] Figure 2 shows the local variations of the generated surface 12 relative to a given overall shape 13, which is flat in this example. These local variations correspond to changes in slope, defined by the normal n and / or tangent t to the generated surface 12 at the locations of these local variations. Thus, the generated surface 12 includes deviations from the overall shape 13, forming depressions and ridges.

[0136] For clarity, the normals n and tangents t are not shown here except for three points on the generating surface 12, but the normals and / or tangents are calculated at all points.

[0137] In this application, the width of the local variation can be defined as the distance between the local variation and the overall shape 13 along the normal at a given point on the overall shape 13.

[0138] If the overall shape is flat, as shown in Figures 7 and 8, any point on the given overall shape can be defined by a height in a single direction z perpendicular to the overall shape 13.

[0139] Figure 8 shows the minimum width a1, which is located upstream of the generation surface 12 and is therefore conventionally considered negative, and the maximum width a2, which is located downstream of the generation surface 12 and is therefore considered positive.

[0140] In the illustrated method, the faces may be discretized into a number of element faces, and it should be noted that these faces can be considered analogous to the points p1, p2, p3, p4, p5, p'1, ​​p'2, p'3, and p'4 described above.

[0141] Figure 11 shows a propagation pattern 16 as seen on a flat screen, perpendicular to the propagation direction and at a distance equal to or close to the propagation distance. If the target surface is also flat and oriented in the same way, this propagation pattern 16 will also be the target pattern seen in Figure 11. Otherwise, it will be distorted.

[0142] Figure 12 shows the generation surface 12 used to form this propagation pattern 16. Since a relief is formed on this surface 12, the object pattern 15 is formed by this relief, and therefore local variations are observed. This object pattern 15, schematically illustrated in Figure 12, corresponds to the distorted shape of the propagation pattern 16.

[0143] If it is desired that the pattern in Figure 11 be a target pattern that can be seen by the driver or a third party on the road, then the propagation pattern needs to be distorted relative to the target pattern in order to see stars on the road as illustrated in Figure 11, since the target pattern is formed by rays oblique to the road, for example, because the rays come from the front headlights, taillights, or turn signals.

[0144] According to the present invention, as shown in Figures 7 and 8, the generated surface 12 can be arranged and calculated such that the transition from one local variation to another is smooth for the majority of the generated surface 12, i.e., the smooth portion that makes up the majority of the surface. This is particularly the case for the portion illustrated in Figure 2. If, for calculation purposes, the local variations are considered to be small regions, especially minute regions, rather than points on the generated surface, the generated surface 12 can also be arranged to smooth the local variations for these smooth portions.

[0145] In particular, one of these smooth portions may have a surface that occupies a large portion of the generated surface.

[0146] The generated surface 12 can be calculated using the first example of the calculation method, which is the method disclosed in the literature by Yue et al.[1]. In this literature, in particular, various steps for constructing the generated surface 12 according to a given example, especially steps for determining the relationship between points on the generated surface 12 and points on the target surface.

[0147] Using the first example of this method, a perfectly flat generated surface 12 can be obtained. The transition from one local variation to another is smooth.

[0148] In order to determine the relationship of the correlation process, in particular, conditions are defined to establish a one-to-one relationship between object points and target points, as in this first method. Thus, the entire generation surface 12 is - By deflecting the incident light rays, each local variation forms a separate portion of the target pattern distinct from the portion of the target pattern formed by other local variations. - Each part of the target pattern is positioned such that it receives rays from only one local variation relative to the entire target pattern.

[0149] This method makes it possible to obtain a good brightness gradient and good resolution. Using this method, for example, the generated surface 12 in Figure 7 can be formed.

[0150] Alternatively, local variations can be arranged such that the generating surface 12 has one or more edges in order to improve contrast and have some dark areas and some areas of maximum luminosity.

[0151] Depending on the circumstances, the generation surface 12 is - At least one edge defining the boundary of a portion of the production surface in a different orientation, and / or causing diffusion such that a portion of the target pattern receives little to no light rays, and thus forms a dark region, and / or - Includes at least one edge that defines the boundary of a portion of the generation surface in a different orientation, such that a portion of the target pattern converges to receive rays from multiple local variations and / or multiple portions of the generation surface.

[0152] This makes it possible to generate patterns with extremely sharp and bright lines or characters, in particular.

[0153] For this purpose, for example, a second calculation method for calculating the generated surface 12, disclosed in the literature by Schwartzburg et al.[2], can be used.

[0154] This second method does not use a one-to-one relationship condition in the correlation process. Although this method is more complex, it can be used to obtain higher contrast, in other words, a higher ratio between bright and dark regions. This method can obtain darker regions than the method of Yue et al.[1] described above. Thus, this second method makes it possible to obtain a clearer boundary between dark and bright regions. The outer parts of the edges are smooth, and the transition from one local variation to another is smooth.

[0155] For example, in Figures 14A to 14F, the method used does not impose a one-to-one relationship constraint to determine the target pattern. In some places, multiple object points p4 and p5 correspond to a single target point p'4. Thus, the generated surface 12 has discontinuities in the slope variation corresponding to the edge 18 appearing on the generated surface 12, which causes it to be indented with respect to the incident ray. Local variations on either side of this edge 18 make it possible to concentrate the rays r4 and r5 onto the line on the target surface to form, for example, a sharp, strong line.

[0156] Outside of this edge 18, particularly above and below it, the correlation process E3 creates a one-to-one relationship between the corresponding object points p1, p2, p3 and the corresponding target points p'1, ​​p'2, p'3, although this relationship is not defined as a constraint.

[0157] Regardless of the method used, each point on the generated surface 12 is associated with a width corresponding to the difference in the overall shape 13, and this width is defined along a direction parallel to the normal to the overall shape 13 at that point.

[0158] For example, as illustrated in Figures 7 and 9, a plane containing the beam of incident light rays in the overall direction is considered. In this plan, a rectangle 17 circumscribing the optical element 10 is considered, where one side of the rectangle 17 may have at least four times, or in particular six times, the width of each local variation, relative to a given overall shape 13 at the location of the local variation, and thus more than six times the maximum width.

[0159] In addition, local variations may have tangents t that form an angle α with a given overall shape between -60° and 60°, or especially between -30° and 30°.

[0160] By accumulating these slope and width conditions, optimal results are achieved, particularly in terms of contrast and sharpness, and more specifically, it becomes possible to propagate the propagation pattern over the range of action at the optimal distance Dp.

[0161] It should be noted that as the size of the light source generating the beam upstream of the optical element 10 decreases relative to the generation surface 12, the projected pattern will become closer to the desired pattern used to construct the generation surface 12. For example, the sides of the rectangle 17 that the optical element 10 circumscribes may be at least 6 times, or especially 30 times, larger than the sides of the light source, particularly if the source is a light-emitting diode.

[0162] The two embodiments shown in Figures 7 to 9 illustrate an optical element 10 that operates by refraction.

[0163] Here, the generating surface 12 is formed on an optical element 10 specifically designated for this purpose. However, the generating surface 12 may also be formed on other functional elements such as the sealing outer lens 6 of the light-emitting device, or on components such as a refractive or reflective optical element of another light-emitting device and / or signaling device of an automatic vehicle system incorporating the second light-emitting device (particularly advantageously, on components of the first device described above).

[0164] Figures 7 to 9 also illustrate the case where the generated surface 12 is located on the exit surface of element 10. However, this is not limiting, and generally speaking, an optical element may have a generated surface on both the incident surface and / or the exit surface. The illustrations in Figures 2 to 5B show examples of refraction.

[0165] The optical element 10 may also operate by reflection, as in the cases shown in Figures 6A to 6D. Here, the optical element is part of a mirror, and the reflective surface of this mirror forms a generated surface 12, which has local variations around its flat overall shape. This mirror may have one or more edges. Here, there are recessed edges, i.e., edges that form the bottom of a depression, defining the boundaries of parts of the surface having relative orientations to each other, and thus these parts make it possible to generate strong, bright lines with a specific shape on the target pattern (not shown).

[0166] The same construction method may be applied to this reflective generation surface 12, thereby allowing the fact that reflection and not refraction occur in various processes. In such a case, the upstream processes are simplified because the rays r1, r2, r3, and r4 reach the generation surface 12 directly according to a given distribution and similarly exit from it directly.

[0167] Figure 13 illustrates another example of a lighting system according to the present invention. In the illustrated case, a vehicle 1 having a vertical axis X is equipped with two lighting systems according to the present invention, which are incorporated here into the right reverse light unit 4 and the left reverse light unit 4, respectively.

[0168] For example, each of these units 4 includes a housing and a sealing outer lens for the corresponding housing, as shown in the previous Figure 2. Each sealing outer lens includes a portion where a diopter between the outer lens and the outer surface forms a generating surface. Each of these generating surfaces receives a portion of the light rays from the corresponding rear lamp light source. A light source specifically designated for this generating surface can also be provided.

[0169] Each generating surface of unit 4 is positioned to generate a target pattern 3 on the road, which forms a pattern consisting of three triangles that indicate to following vehicles to turn to the right relative to the direction of vehicle movement indicated by arrow X.

[0170] According to the option that the signal function of the first device instructs reversing, the pattern may include straight strips to assist the driver, for example, for steering when reversing, by marking the overall dimensions of the vehicle.

[0171] Figure 13 is an overhead view, so the pattern is stretched, but it is perceived as not being stretched as much from a following vehicle. The object pattern (not shown) formed by the relief of the corresponding generating surface has this distorted target pattern composed of a series of three triangles.

[0172] As is evident in this example, the distance of the pattern between the generating surface and the target surface, i.e., the road, varies depending on the direction of propagation, and also depending on the orientation of the vehicle 1, for example, whether or not it is loaded. Here, the generating surface is positioned such that, when the orientation of the vehicle 1 is horizontal on a horizontal road, a given optimal distance Dp is greater than, for example, twice as large, the distance between the generating surface and the road in the propagation direction of the propagation pattern. This makes it possible to provide a visible and clear target pattern regardless of the orientation of the vehicle 1, especially its orientation. Therefore, the target pattern can be seen while driving uphill or downhill, while braking or accelerating, and regardless of the load on the vehicle.

[0173] The present invention is not limited to the embodiments described above, but extends to all embodiments covered by the claims.

[0174] List of cited references: [1] Yonghao Yue,Kei Iwasaki,Bing-Yu Chen,Yoshinori Dobashi,Tomoyuki Nishita.Poisson-Based Continuous Surface Generation for Goal-Based Caustics,ACM Transactions on Graphics,Vol.31,No.3,Article 31(May 2014). [2] Yuliy Schwartzburg,Romain Testuz,Andrea Tagliasacchi,Mark Pauly.High-contrast Computational Caustic Design,ACM Transactions on Graphics(Proceedings of ACM SIGGRAPH 2014),Vol.33,Issue 4,Article No.74(July 2014).

Claims

1. A system for projecting a light beam from a vehicle, comprising a first device configured to generate a first beam (2) for performing a signaling function, and a second device configured to generate at least a second beam for projecting a pattern (3), The first device includes at least one refractive optical member for forming the first beam (2), The second device system comprises at least one optical element having a controlled pattern-generating surface (12) configured to deflect light rays from a light source (200), wherein the pattern-generating surface (12) has local variations arranged to form a predetermined pattern (3) on the second beam.

2. The pattern generating surface (12) is a reflective or refractive surface that extends within a given overall shape and has local variations in shape around this given overall shape. These local variations are distributed across the entire pattern-generating surface (12) to provide a relief that forms an object pattern across the entire generation surface. These different local variations are such that the majority of the generating surface is smooth, and the pattern generating surface (12) is positioned to deflect a beam of light having a given distribution incident on the entire pattern generating surface (12) in different orientations according to the local variations encountered by the light, thereby forming a deflected beam that propagates a distinguishable propagation pattern upstream of a finite given optimal propagation distance and over an operating range extending at least to that extent, the propagation pattern corresponding to a distorted projection of the object pattern, and the optical element is positioned such that the propagation pattern is visible from outside the light-emitting device and within the operating range and / or at a distance substantially equal to the optimal distance (D １ , D ２ The system according to claim 1, which is arranged to project onto a target surface located at ).

3. The system according to claim 1, wherein the first device and the second device have at least one common light source (200).

4. The system according to claim 1, wherein the first device and the second device have at least one common optical element.

5. The system according to claim 4, wherein the at least one common optical element includes at least one common dioptric optical element.

6. The system according to claim 5, comprising a headlamp unit (4) housing the first device and the second device, wherein the at least one common dioptric optical element comprises an outer lens (6) sealing the headlamp unit (4).

7. The system according to claim 5, wherein the at least one common dioptric optical element includes a waveguide (25).

8. The system according to claim 4, wherein the at least one common optical element includes a reflector (22).

9. The system according to claim 4, wherein the at least one common optical element includes an optical element having the pattern generating surface (12).

10. The system according to claim 4, wherein the at least one common optical element includes a dioptric optical element that forms the refractive optical member for shaping the first beam (2).

11. The system according to claim 1, wherein the second device includes a plurality of optical elements (10), each having a pattern generation surface (12).

12. The system according to claim 11, wherein the first device and the second device each have at least one common optical element, and the optical elements (10), each having a pattern generating surface (12), are spaced apart along the longitudinal direction of the common optical element.

13. The system according to claim 1, wherein the signal function is selected from among a direction change instruction, a reverse instruction, a brake instruction, and a hazard light instruction.

14. The system according to any one of claims 1 to 12, wherein the pattern includes a plurality of parts arranged at intervals from one another.

Images