Lighting device for a vehicle, image-acquiring method, computing element, computer program, and motor vehicle comprising a lighting device

Abstract

The present invention relates to a lighting device for a vehicle comprising at least one light source (7, 8) provided with a shutter (11) through which the emitted light is directed towards a lens (12) defining the field of view (HBFOV) of the device, thus projecting a defined luminous pattern to a defined distance. The device (1, 16) is characterised in that the light source comprises a first light source (7) emitting in the visible spectrum and a second light source (8) emitting in the infrared spectrum, and, interposed between the light source (7, 8) and the lens (12), a filter (13) that lets visible light (WL) pass and that reflects infrared (IR) towards an infrared reflector (14, 18) defining the area (IRFOV) of projection of infrared light independently of the field of view (HBFOV) projected by the visible light source (7).

Description

Vehicle lighting device, image acquisition method, computer component, computer program and motor vehicle including a lighting device

[0001] The present invention is related to the field of lighting and / or signaling devices for motor vehicles, in particular those intended for automobiles.

[0002] The invention relates to a method of acquiring images using a lighting device for a motor vehicle.

[0003] The invention relates to a computer element comprising means for implementing the steps of an image acquisition process using a lighting device.

[0004] The invention also relates to a computer program, executable by a control unit, and comprising instructions which cause the control unit to execute the steps of an image acquisition process using a lighting device.

[0005] The invention finally relates to a motor vehicle comprising a lighting device.

[0006] Modern vehicles are equipped with numerous sensors located all around the body. These sensors monitor the environment to assist the driver in preventing accidents and, in the near future, to achieve autonomous driving without driver intervention. For example, Lidar systems using lasers, infrared sensors, or multiple cameras are known for measuring distances around the vehicle and monitoring the surroundings.All these data acquisition devices are located at various points on the vehicle so that a vehicle control unit can monitor the environment, such as painted road markings. Based on the detections and calculations performed by the control unit, it can decide either to emit an audible signal to prompt the driver to turn the steering wheel, or to activate a motor in the steering column to correct the vehicle's trajectory. Several optical sensors (or sometimes other types) may be installed to monitor the environment in front of or behind the vehicle, allowing the control unit to either warn the driver of an impending or nearby obstacle or hazard, or to directly apply the brakes with varying degrees of severity depending on the level of urgency.

[0007] In order to perform detection, followed by efficient analysis of the detection signal generated by the detectors, such as those mentioned above, the detectors are sometimes accompanied by appropriate lighting devices designed to illuminate the detection zone(s). Such lighting devices are generally placed alongside the vehicle's standard lighting equipment.

[0008] A recurring problem in the field of lighting systems is that visibility conditions vary widely depending on natural factors such as the time of day and weather, but also on environmental factors, such as street lighting, particularly in urban areas, and the density of traffic with vehicles traveling onward or laterally. Generally, regulations aim to ensure the safety and proper functioning of lighting systems, and certain parameters, such as their range, width, and intensity, are defined to guarantee good visibility of the vehicle from the outside and good visibility of the vehicle's surroundings for the occupants. Consequently, regulations often result in lighting levels exceeding what is necessary for the safety of road users.

[0009] Furthermore, the two functions, detection and lighting, do not have the same field of view (FOV, often expressed in degrees). The field of view for the detection function is wide, while the field of view for lighting is narrower. Moreover, the need to integrate sensors in various locations near or far from light sources such as vehicle lighting systems poses a production cost problem, particularly impacting the vehicle's bodywork and glazing. In addition, the positioning of the sensors on the vehicle can generate integration and / or body design problems by creating undesirable protrusions or irregularities in shape, and especially integration problems, for example, with electrical circuits or even overlap with other essential devices and components.

[0010] A primary objective of the present invention is to overcome the problems of size and production cost with regard to driver vision lighting and illumination for the detection function. Another objective is to guarantee the specific characteristics of the lighting and illumination with respect to the field of vision. A further objective is to optimize the energy consumption of both the lighting and illumination functions.

[0011] This goal is achieved by a lighting device for a vehicle comprising at least one light source equipped with a shutter through which the emitted light is directed towards a lens determining the field of vision of said device, thus projecting a determined light pattern at a determined distance, said device being characterized in that said light source comprises: - a first light source emitting in the visible spectrum and a second light source emitting in the infrared spectrum, and - a filter, interposed between said light sources and said lens, allowing visible light to pass through, and reflecting infrared light towards an infrared reflector determining the area of ​​projection of the infrared light, independently of the field of vision projected by the visible light source.

[0012] In other words, the light from the first light source emitting in the visible spectrum and the light from the second light source emitting in the infrared spectrum are advantageously integrated into a single lighting device. This combination allows for cost reductions and space savings within the vehicle body. The light from the first light source emitting in the visible spectrum and the light from the second light source emitting in the infrared spectrum are combined and then separated into a visible component for general illumination and an infrared component for detection illumination.

[0013] According to another feature, the said first visible light source may include an electroluminescent source emitting in the blue spectrum and emitting towards at least one mirror facing the shutter and equipped with a phosphor plate to generate white light in the visible spectrum, directed towards the lens.

[0014] According to another feature, said second infrared light source may include an electroluminescent source emitting in the direction of said mirror facing the shutter and equipped with the phosphor plate, directed towards the filter.

[0015] According to another characteristic, the said infrared reflector can be a passive and stationary reflector whose shape determines the area of ​​projection of the infrared light.

[0016] According to another feature, a lens, focusing infrared light into an infrared beam, can be interposed between said filter and said infrared reflector, which is a movable reflector whose orientation along two degrees of freedom can be controlled by a control unit to determine the successive positions of the infrared beam over time.

[0017] According to another peculiarity, the first visible light source includes a laser emitting in the blue spectrum and the second light source includes a laser emitting in the infrared spectrum.

[0018] According to another peculiarity, the laser emitting in the blue spectrum, the laser emitting in the infrared spectrum, the mirror and the phosphor plate are mounted in a unit.

[0019] According to another feature, a method for acquiring images from the projection area of ​​infrared light obtained by the lighting device according to any one of the preceding claims may include the steps of: - illuminating a projection area with infrared light emitted by the lighting device; - acquiring the infrared light emitted back by the projection area; and - analyzing the acquired images obtained.

[0020] Another objective of this application is to propose a computer element that will at least partially overcome the drawbacks of the prior art.

[0021] This goal is achieved by a computer element comprising means for implementing the steps of an image acquisition process according to various embodiments of the invention.

[0022] Another objective of this application is to propose a computer program that will at least partially overcome the drawbacks of the prior art.

[0023] This goal is achieved by a computer program comprising instructions which, when the program is executed by a control unit, cause the control unit to execute the steps of an image acquisition process according to various embodiments of the invention.

[0024] A final objective of this application is to propose a motor vehicle equipped with a lighting device that at least partially overcomes the disadvantages of prior art technologies.

[0025] This goal is achieved by a motor vehicle equipped with a lighting device, as described and claimed.

[0026] Unless otherwise defined, all terms, including technical and scientific terms, used in this document shall be interpreted in accordance with industry usage, particularly in the field of motor vehicle lighting and signaling, especially for automobiles. For example, the terms "range," "width," and "intensity" are commonly used and may be interpreted to also encompass other terms used to define light beams, including vertical and horizontal angles or focal lengths. Similarly, other terms such as "field of view" (FOV, often expressed in degrees) may be used without any particular limitation in this application.It is also understood that terms in common usage should be interpreted as being customary in the art concerned and not in an idealized or overly formal sense and should not be interpreted restrictively unless expressly defined as such in this document.

[0027] In the present application, as is generally accepted in the field of patent applications, the terms "includes", "comprises" and "includes" and their derivatives (such as "comprising", "comprising", etc.) should not be understood in an exclusionary sense, that is to say, these terms should not be interpreted as excluding the possibility that what is described and defined may include other elements, steps, etc.

[0028] The term "lighting device" in this application refers to both lighting itself and signaling, including: devices that illuminate the vehicle's surroundings – either so that the driver can see, such as dipped headlights (LB, according to the English term "Low Beam") or main beam headlights (HB, according to the English term "High Beam"), even though the latter are generally prohibited under certain conditions, particularly in built-up areas – or so that the driver can be seen, such as position lights (PL, according to the English term "position light"), rear position lights (RPL, according to the English term "Rear Position Light") or daytime running lights (DRL, according to the English term "Day Running Light"), but also devices that signal a driver's actions to other road users, such as stop lights (SL, according to the English term "Stop Light").Direction indicator lights (turn signals or TI, according to the English term "Turn Indicator") or hazard warning lights (W, according to the English term "Warning").

[0029] The lighting system therefore comprises a plurality of lighting or signaling functions, which may be of the type of examples PL, LB, HB, DRL, SL, TI, W provided above, which are neither exhaustive nor limiting. Generally, the lighting system also includes the control unit, which allows the system to be operated and the process to be implemented. Each lighting system may include one or more light sources depending on the type of lighting, for example, incandescent bulbs or light-emitting diodes (LEDs), or others. The term "lighting pattern" is used in this application with the same meaning as the term "lighting configuration" and is not limited to a pattern in the strict sense and therefore does not necessarily imply a variation in photometry.

[0030] Other features and advantages of the present invention will become more apparent upon reading the following description of various embodiments, made with reference to the accompanying drawings. Indeed, to supplement the description and to facilitate a better understanding of the invention, a set of drawings is provided. These drawings illustrate one embodiment of the invention and form an integral part of the description, which should not be interpreted as limiting the scope of the invention, but merely as an example of how the invention can be implemented. The drawings include the following figures:

[0031] This represents a schematic view of a lighting device according to one of the embodiments of the invention; and

[0032] The figure represents a schematic view of a lighting device according to another embodiment of the invention.

[0033] The present invention relates to a lighting device intended for a motor vehicle, such as a car, truck or motorcycle.

[0034] In one embodiment shown in Figure 1, the lighting device 1 comprises a surface-mount device (SMD) 2, having a basin 3 and two opposing inclined faces 4 and 6. Two lasers 7 and 8 are mounted on each of the two inclined faces 4 and 6 of the base 2. The first laser 7, mounted on the inclined face 4 located on the left in Figure 1, is of the type emitting light in the blue spectrum (BL arrow). The second laser 8, mounted on the inclined face located on the right in Figure 1, is of the type emitting light in the infrared spectrum (IR arrow). The surface-mount device 2 has the advantage of having a single plate for dissipating the heat generated by both lasers 7 and 8. The surface-mount device 2 allows for a more compact mounting of the two lasers 7 and 8 and, consequently, of the entire lighting device 1.

[0035] Preferably, each of the two lasers 7 and 8 emits its own BL and IR light beams, each converging towards at least one mirror equipped with a phosphor plate 9. The phosphor plate 9 has the property of re-emitting white light when irradiated by blue light. For safety reasons, and thanks to this arrangement, the lights from the two lasers 7 and 8 are not projected onto the road or directed directly towards other drivers and road users. Depending on the device configuration, one or more mirrors can be used to direct the two lights appropriately.

[0036] The light reflected by the mirror and its phosphor plate 9 has a white component (WL) and an infrared component (IR). A shutter 11 is fitted to prevent stray light from the white and infrared (WL and IR) light. The emitted light (WL) is directed onto a lens 12, which defines the field of vision of the lighting device 1, thus projecting a specific light pattern at a specific distance to provide a field of vision for high beams (HBFOV).

[0037] A filter 13 is interposed between the two lasers 7 and 8 and the lens 12. The filter 13 has the property of allowing white light (WL) to pass through to the lens 12, and of reflecting infrared (IR) light. As an example, the filter 13 allows white light (WL) with a wavelength frequency approximately between 350 nm and 650 nm to pass through.

[0038] In some embodiments, the infrared (IR) light from the filter 13 is directed towards an infrared reflector 14, which defines the field of view of the lighting device 1, thus projecting a specific light pattern at a specific distance to provide a field of view for infrared (IRFOV) detection. Infrared detection is performed by LIDAR flashes (light detection and range estimation) or by laser, or, in English, by "Light Detection and Ranging" or "Laser Imaging Detection and Ranging".

[0039] In some embodiments, the infrared reflector 14 generates a wide, or even very wide, field of vision, directed towards the entire field (depending on the trajectory) facing the motor vehicle. The field of vision of the infrared light IRFOV projected by the second laser 8 is independent of the field of vision of the white light HBFOV projected by the first laser 7.

[0040] In other embodiments, for example as shown in Figure 1, the lighting device 16 comprises, similarly to one of the embodiments in Figure 1, a surface-mount unit 2 having a basin 3 and two opposing inclined faces 4 and 6. Two lasers 7 and 8 are mounted on each of the two inclined faces 4 and 6 of the base 2. The first laser 7, mounted on the inclined face 4 located on the left in Figure 1, is of the type emitting light in the blue spectrum (Arrow BL). The second laser 8, mounted on the inclined face located on the right in Figure 1, is of the type emitting light in the infrared spectrum (Arrow IR). The surface mount unit 2 has the advantage of having a single plate for the dissipation of heat generated by both lasers 7 and 8. The surface mount unit 2 allows for a more compact mounting of both lasers 7 and 8 and therefore of the entire lighting device 16.

[0041] In some embodiments, each of the two lasers 7 and 8 emits its own beams of white and infrared light, each converging towards a mirror equipped with a phosphor plate 9. The phosphor plate 9 has the property of re-emitting white light when irradiated by blue light. For safety reasons, and thanks to this arrangement, the lights from the two lasers 7 and 8 are not projected onto the road or directed towards other drivers and road users.

[0042] The light reflected by the mirror and its phosphor plate 9 has a white component (WL) and an infrared component (IR). A shutter 11 is fitted to prevent stray scattering of white and infrared (WL and IR) light. The emitted WL light is directed onto a lens 12, which defines the field of vision of the lighting device 16, thus projecting a specific light pattern at a specific distance to provide a field of vision for high beams (HBFOV).

[0043] Preferably, a filter 13 is interposed between the two lasers 7 and 8 and the lens 12. The filter 13 has the property of allowing white light (WL) to pass through to the lens 12, and of reflecting infrared (IR) light. As an example, the filter 13 allows white light (WL) with a wavelength frequency approximately between 350 nm and 650 nm to pass through.

[0044] In some embodiments, the infrared (IR) light from the filter 13 is directed to a focusing lens 17 that concentrates the infrared (IR) light. The infrared (IR) light exiting the focusing lens 17 is directed to a movable collimating reflector or mirror 18. The movable reflector 18 has a variable orientation driven by a microelectromechanical system (MEMS) with two degrees of freedom (see arrows) and is controlled by a control unit to determine the successive positions of the infrared (IR) beam over time.

[0045] The movable infrared reflector 18 defines the field of view of the lighting device 16, thus projecting a specific light pattern at a specific distance to provide a field of view for infrared detection (IRFOV). In some embodiments, infrared detection is performed by scanning or LiDAR scanning, detecting and estimating the distance using light or laser, or, in English, using the terms "Light Detection and Ranging" or "Laser Imaging Detection and Ranging".

[0046] The mobile infrared reflector 18 generates a narrower field of vision than that of white light, even a very narrow one, directed towards and allowing scanning of the entire field or trajectory in front of the motor vehicle. The field of vision of the infrared light IRFOV projected by the second laser 8 is independent of the field of vision of the white light HBFOV projected by the first laser 7.

[0047] The lighting device (1, 16) according to one or the other embodiment of the present invention allows the implementation of a method for acquiring images from the projection area of ​​the infrared light IRFOV, thanks to a computer element in a control unit and a corresponding computer program.

[0048] The method includes infrared illumination, in which the field of view of the infrared light IRFOV is illuminated with infrared light emitted by the lighting device 1 and by the second laser 8. With the lighting device 1 according to one embodiment of the invention, the field of view of the infrared light IRFOV is illuminated by successive flashes or pulses. With the lighting device 16 according to the other embodiment of the invention, the field of view of the infrared light IRFOV is illuminated by scanning lines. Thus, the method may include infrared acquisition by a sensor (not shown) that acquires the infrared light emitted back by the projection area IRFOV. The images obtained from the previous acquisition are then analyzed, preferably in real time.

[0049] This application describes various technical features and advantages with reference to the figures and / or various embodiments. Those skilled in the art will understand that the technical features of a given embodiment can in fact be combined with features of another embodiment unless the contrary is explicitly stated, or it is obvious that such features are incompatible, or that the combination does not provide a solution to at least one of the technical problems mentioned in this application. Furthermore, the technical features described in a given embodiment can be isolated from the other features of that embodiment unless the contrary is explicitly stated.

[0050] Detailed list of references in the figures: 1 lighting device according to one of the embodiments 2 surface-mount unit 3 basin 4 inclined face 6 inclined face 7 white light laser 8 infrared laser 9 mirror and phosphor plate 11 shutter 12 lens 13 filter 14 reflector 16 lighting device according to the other embodiment 17 focusing lens 18 movable reflector

Claims

Lighting device for a vehicle comprising at least one light source (7, 8) equipped with a shutter (11) through which the emitted light is directed towards a lens (12) determining the field of vision (HBFOV) of said device, thus projecting a determined light pattern at a determined distance, said device (1, 16) being characterized in that said light source comprises: a) a first light source (7) emitting in the visible spectrum and a second light source (8) emitting in the infrared spectrum, and b) a filter (13), interposed between said light sources (7, 8) and said lens (12), allowing visible light (WL) to pass through, and reflecting infrared (IR) towards an infrared reflector (14, 18) determining the infrared light projection area (IRFOV), independently of the field of vision (HBFOV) projected by the visible light source (7). Device according to claim 1, wherein said first visible light source comprises an electroluminescent source (7) emitting in the blue spectrum and emitting towards at least one mirror, facing the shutter (11), and provided with a phosphor plate (9) to generate white light in the visible spectrum, directed towards the lens (12). Device according to claim 2, wherein said second infrared light source comprises an electroluminescent source (8) emitting in the direction of said mirror, facing the shutter (11), and equipped with the phosphor plate (9), directed towards the filter (13). Device according to any one of the preceding claims, wherein said infrared reflector is a passive and stationary reflector (14) whose shape determines the infrared light projection area (IRFOV). Device according to any one of claims 1 to 3, wherein a lens (17), focusing infrared light into an infrared beam, is interposed between said filter (13) and said infrared reflector which is a movable reflector (18), the orientation of which along two degrees of freedom is controlled by a control unit to determine the successive positions of the infrared beam over time. Device according to any one of the preceding claims, wherein the first visible light source comprises a laser emitting in the blue spectrum (7) and the second light source comprises a laser emitting in the infrared spectrum (8). Device according to claim 6, wherein the laser emitting in the blue spectrum (7), the laser emitting in the infrared spectrum (8), the mirror and the phosphor plate (9) are mounted in a unit (2). A method for acquiring images from the projection area of ​​infrared light obtained by the lighting device according to any one of the preceding claims, comprising the steps of: a) Illuminating a projection area with infrared light emitted by the lighting device; b) Acquiring the infrared light emitted back from the projection area; etc.) Analyzing the acquired images obtained. Computer element comprising means for implementing the steps of a process according to claim 6. Computer program comprising instructions which, when the program is executed by a control unit, cause the control unit to execute the steps of a process according to claim 6. Vehicle equipped with a lighting device according to any one of claims 1 to 5.

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