Vehicle display system and vehicle including such a display system

Abstract

The present invention relates to a method and device for controlling a head-up display (HUD) installed in a vehicle. The method selects (51) a display mode for each floating image from a single-plane display mode and a multi-plane display mode, said single-plane display mode defining a display mode in which the HUD control device is configured to redirect said at least one light beam to a single image plane, and said multi-plane display mode defining a display mode in which the HUD is configured to redirect the light beams to image planes positioned at different distances from a viewpoint of the vehicle; adapts (52) the behavior of the HUD according to the selected display mode; and adapts (53) graphic objects of the displayed floating images according to the selected display mode. Figure 5 (for the abstract)

Description

Title of the invention: Vehicle display system and vehicle comprising such a display system Technical field

[0001] The present invention relates to a display system on board a vehicle, for example an automobile. The present invention also relates to a vehicle dashboard comprising such a display system. Technological background

[0002] Some contemporary vehicles have several screens on board to display information useful to the driver for driving the vehicle as well as comfort information, such as, for example, information for interacting with the infotainment system, also called the IVI system (from the English "In-Vehicle Infotainment" or in French "Infodivertissement embargo"), of the vehicle.

[0003] Among these screens, it is known to embed one or more LCD (Liquid Crystal Display) type screens, for example TFT (Thin-Film Transistor) type, or OLED (Organic Light-Emitting Diode) type.

[0004] It is also known to equip certain vehicles with a head-up display device which makes it possible to display information useful for driving the vehicle at the driver's eye level, for example on a transparent or semi-transparent strip arranged on the dashboard behind the steering wheel. Such a head-up display device is for example described in document WO2013 / 189808 A published on December 27, 2013.

[0005] Head-up display devices are known which are configured to display information on a single plane at a given depth, generally after the windshield. This is referred to as a single-plane head-up display device.

[0006] Multi-plane head-up display devices are also known, i.e. devices which are configured to enable the display of information useful for driving the vehicle on image planes located at different depths after the windshield.

[0007] Multi-plane head-up displays are beginning to be installed in vehicles as a replacement for single-plane head-up displays. Users of these vehicles may not accept these multi-plane head-up displays and would prefer to return to single-plane devices.

[0008] It is necessary to allow a user of a vehicle to be able to choose between a single-plane head-up display device and a multi-plane device without installing these two types of devices in the same vehicle. Summary of the invention

[0009] An object of the present invention is to resolve at least one of the drawbacks of the prior art.

[0010] An object of the present invention is to meet the wishes of vehicle users regarding the display of image data by a head-up display device.

[0011] Another object of the present invention is to improve the experience of these users with regard to the display of image data representative of a state of a component of a vehicle or its close environment.

[0012] According to a first aspect, the present invention relates to a method for controlling a head-up display device on board a vehicle, said head-up display device comprising a projector configured to project at least two light beams each carrying data representative of a floating image, and an optical processing means configured to redirect each light beam towards an image plane, said method comprising the following steps: - selecting a display mode for the data representative of each floating image from a single-plane display mode and a multi-plane display mode, said single-plane display mode defining a display mode in which the projector and / or the optical processing means are configured to redirect said at least one light beam towards a single image plane and, said multi-plane display mode defining a display mode in which the projector and / or the optical processing means are configured to redirect the light beams towards image planes positioned at different distances from a point of view of the vehicle; - adaptation of the behavior of the projector and / or the behavior of the optical processing means according to the selected display mode; and - adaptation of graphic objects of floating images displayed on the or each of the image planes according to the selected display mode.

[0013] The method allows a user of a vehicle, typically the driver of the vehicle, to choose whether image data representing, for example, a state of a component of the vehicle, its consumption, etc., or relating to its immediate environment are displayed on a single image plane positioned at a predefined distance from the user or on several image planes positioned at different predefined distances from the user.

[0014] The method thus allows switching from a single-plane display mode to a multi-plane display mode and conversely from a multi-plane mode to a single-plane mode.

[0015] According to a particular and non-limiting exemplary embodiment, the display mode is selected by an action of a user of the vehicle on a human-machine interface, called HMI.

[0016] According to a particular and non-limiting exemplary embodiment, the optical processing means comprising several orientable mirrors, the behavior of the optical processing means comprises an orientation of at least one of the mirrors to redirect at least one light beam projected by the projector in a particular direction so that the floating images are displayed either on the same image plane or on several image planes depending on the selected display mode.

[0017] According to a particular and non-limiting exemplary embodiment, the adaptation of the graphic objects of the floating images comprises the resizing of at least one of said graphic objects, a modification of the light intensity with which at least one of said graphic objects is displayed or a repositioning of at least one of said graphic objects on an image plane.

[0018] According to a particular and non-limiting exemplary embodiment, when the floating images are previously displayed on several image planes and the single-plane display mode is selected, the adaptation of the graphic objects of the floating images comprises a superposition of the graphic objects of the floating images on a single image plane.

[0019] According to a second aspect, the present invention relates to a device for controlling a head-up display device on board a vehicle, said device comprising a memory associated with at least one processor configured for implementing the steps of the method according to the first aspect of the present invention.

[0020] According to a third aspect, the present invention relates to a display system on board a vehicle, said display system comprising: - a head-up display device comprising a projector configured to project at least two light beams each carrying data representative of a floating image and an optical processing means configured to redirect each light beam towards an image plane; - a human-machine interface, called HMI, configured to select either a single-plane display mode or a multi-plane mode, said single-plane display mode defining a display mode in which the projector and / or the optical processing means are configured to redirect said at least one light beam towards a single image plane and, said multi-plane display mode defining a display mode in which the projector and / or the optical processing means are configured to redirect the light beams towards image planes positioned at different distances from a point of view of the vehicle; - a device for controlling the head-up display device according to the second aspect of the present invention.

[0021] According to a fourth aspect, the present invention relates to a computer program comprising instructions for implementing the method according to the first aspect of the present invention, when these instructions are executed by a processor.

[0022] Such a computer program may use any programming language, and be in the form of source code, object code, or intermediate code between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0023] According to a fifth aspect, the present invention relates to a computer-readable recording medium on which is recorded a computer program comprising instructions for carrying out the steps of the method according to the first aspect of the present invention.

[0024] According to a sixth aspect, the present invention relates to a vehicle comprising a display system according to the third aspect of the present invention or a device according to the second aspect of the present invention. Brief description of the figures

[0025] Other characteristics and advantages of the invention will emerge from the description of the non-limiting exemplary embodiments of the invention below, with reference to the appended figures 1 to 5, in which:

[0026] [Fig.l] schematically illustrates an environment for projecting floating images in a vehicle, according to a particular and non-limiting exemplary embodiment of the present invention.

[0027] [Fig.2] schematically illustrates a field of vision associated with a driving position of the vehicle of [Fig.l], according to a particular and non-limiting exemplary embodiment of the present invention;

[0028] [Fig.3] schematically illustrates an on-board display system in the vehicle of [Fig.l], according to a particular and non-limiting exemplary embodiment of the present invention;

[0029] [Fig.4] schematically illustrates a device configured to control a head-up display device of the display system of [Fig.3], according to a particular and non-limiting exemplary embodiment of the present invention; and

[0030] [Fig.5] illustrates a flowchart of the different steps of a method for controlling a head-up display device on board a vehicle of [Fig.l], according to a particular and non-limiting exemplary embodiment of the present invention. Description of examples of implementation

[0031] A method and device for controlling a head-up display device embedded in a vehicle, and an embedded display system in a vehicle will now be described in the following with reference jointly to Figures 1 to 5. The same elements are identified with the same reference signs throughout the description which follows.

[0032] According to a particular and non-limiting example of embodiment of the invention, a mode for displaying data representative of floating images is selected from a single-plane display mode and a multi-plane display mode. The single-plane display mode defines a display mode in which a projector and an optical processing means of a head-up display device are configured to redirect each light beam to an image plane. The multi-plane display mode defines a display mode in which the projector and the optical processing means are configured to redirect the light beams to image planes positioned at different distances from a point of view of the vehicle.A behavior of the projector and / or a behavior of the optical processing means are adapted according to the selected display mode and graphic objects of the displayed floating images are adapted on the or each of the image planes according to the selected display mode.

[0033] [Fig.l] schematically illustrates an environment for displaying floating images in a vehicle, according to a particular and non-limiting exemplary embodiment of the present invention.

[0034] [Fig.l] shows a view of the interior of the front part of the passenger compartment of a vehicle 10 including in particular a steering wheel, a dashboard, and a windshield 100.

[0035] The vehicle 10 corresponds for example to a vehicle with a thermal engine, with electric motor(s) or even to a hybrid vehicle with a thermal engine and one or more electric motors. The vehicle 1 thus corresponds for example to a land vehicle, for example a car, a truck, a bus, a tram, a train, etc.

[0036] The vehicle 10 for example carries a set of sensors configured to obtain data on the environment of the vehicle 10, this data or part of it being used in particular for driving in autonomous mode of the vehicle 10. This or these sensors correspond for example to sensors of one or more systems for detecting objects in the environment of the vehicle 10, the data obtained from this or these sensors making it possible for example to detect objects in the environment of the vehicle 10, for example in front of the vehicle 10. This or these object detection systems are for example associated with or included in one or more driving assistance systems, called AD AS systems (from the English “Advanced Driver-Assistance System” or in French “Système d'aide à la conduite avance”).

[0037] The sensor(s) associated with these object detection systems correspond, for example, to one or more of the following sensors: - one or more millimeter wave radars arranged on the vehicle 10, for example at the front, at the rear, on each front / rear corner of the vehicle; each radar is adapted to emit electromagnetic waves and to receive the echoes of these waves returned by one or more objects, for the purpose of detecting obstacles and their distances from the vehicle; and / or - one or more LIDAR(s) (from the English “Light Detection And Ranging”, or “Light Detection and Ranging” in French), a LIDAR sensor corresponding to an optoelectronic system composed of a laser emitting device, a receiving device comprising a light collector (to collect the part of the light radiation emitted by the emitter and reflected by any object located in the path of the light rays emitted by the emitter) and a photodetector which transforms the collected light into an electrical signal; a LIDAR sensor thus makes it possible to detect the presence of objects located in the emitted light beam and to measure the distance between the sensor and each detected object; and / or - one or more cameras (associated or not with a depth sensor) for the acquisition of one or more images of the environment around the vehicle located in the field of vision of the camera(s).

[0038] The vehicle 10 also carries, for example, a navigation system, which uses, for example, geolocation information provided by a satellite positioning system such as the GPS system (from the English “Global Positioning System” or in French “Système mondial de positioning”) or the Galileo system. This geolocation information is combined with mapping data, in particular road data, to display the route of the route on a map obtained from the mapping data.

[0039] The vehicle 10 advantageously carries a display system comprising a head-up display device 3 and a device 4 for controlling the head-up display device 3.

[0040] The head-up display device 3 is configured to display floating images each comprising one or more graphic objects by projection, onto a surface 101 of the windshield 100, of at least two light beams, each carrying data representative of a floating image.

[0041] At least one floating image advantageously comprises a set of graphic objects each representative of a parameter or an operating state of the vehicle 10. By way of example, graphic objects representative of parameters or operating states of the vehicle 10 correspond to all or part of the following information, according to all possible combinations: - information representing instantaneous speed; and / or - information representative of rotation of a motor shaft (also called in- tachometer training); and / or - information representative of the mileage traveled; and / or - information representative of a fuel level or the state of charge of the battery in the case of an electric vehicle; and / or - information representative of the temperature of an engine coolant; and / or - at least one item of information representing a warning light (for example, battery charge warning light, engine oil pressure warning light, engine oil or coolant temperature warning light, brake failure warning light, etc.), corresponding for example to a pictogram displayed or taking on a specific color in the event of an alert; and / or - at least one item of information representing a warning indicator (for example, engine oil level indicator, airbag indicator, brake pad wear indicator, etc.), corresponding for example to a pictogram displayed or taking on a specific color in the event of a warning; and / or - at least one item of information representing an indicator indicating the operation of an on-board system (positioning, dipped or main beam indicator, hazard warning light indicator, rear window demisting indicator, etc.), corresponding for example to a pictogram displayed or taking on a specific color in the event of the on-board system being put into operation.

[0042] Of course, the above list of information displayed via a floating image is given as an example and is not limited to the examples above. In addition, said displayed information corresponds for example to the information usually displayed on the dashboard (or instrument panel).

[0043] At least one other floating image advantageously comprises a set of graphic objects each representing contextual or environmental information of the vehicle 10. By way of example, contextual or environmental information of the vehicle 10 corresponds to all or part of the following information, according to all possible combinations: - information representative of mapping of the environment of the vehicle 10, for example obtained from the navigation system on board the vehicle or from a navigation system installed on a mobile communication device (for example a smartphone) connected in wireless communication with the vehicle 10; and / or - information representative of vehicle navigation, for example a route to be followed by the vehicle, the current position of the vehicle, the instantaneous speed of the vehicle, the speed limit applicable on the portion of road on which the vehicle 10 is traveling; this information is for example obtained from the in-vehicle navigation system or navigation system installed on a mobile communication device; and / or - information representative of an object detected in the environment, for example the presence of a vehicle preceding the vehicle 10, the presence of a pedestrian or an animal on the roadway in front of the vehicle 10, the presence of a road sign, the presence of a stationary object on the roadway, the presence of a tunnel entrance, etc.; this or this information is for example obtained from one or more object detection sensors on board the vehicle 10 and for example associated with one or more AD AS systems of the vehicle 10; according to a variant, this information is received from another vehicle or from an infrastructure connected to the vehicle 10 in wireless communication according to a vehicle-to-everything (V2X) communication mode comprising vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I) and / or vehicle-to-pedestrian (V2P) communication modes; and / or . - information representative of an event detected in the environment, for example information on a disturbance on the road, for example an accident, a traffic jam, information on particular climatic conditions that may disrupt traffic (snow, fog, rain, ice); this or this information is for example obtained from one or more object detection sensors on board the vehicle 10 and for example associated with one or more AD AS systems of the vehicle 10; according to a variant, this information is received from another vehicle or from the infrastructure connected to the vehicle 10 in wireless communication according to a vehicle-to-everything (V2X) communication mode comprising vehicle-to-vehicle (V2V) communication modes, from vehicle to infrastructure (V2I) "vehicle-to-infrastructure") and / or vehicle-to-pedestrian V2P (from the English "vehicle-to-pedestrian"); in another variant, this information is received from one or more servers in the "cloud" (or "nuclé" in French) via a 4G or 5G cellular wireless network.

[0044] [Fig. 2] schematically illustrates a field of vision associated with a driving position of the vehicle 10 of [Fig. 1], according to a particular and non-limiting exemplary embodiment of the present invention.

[0045] [Fig. 2] illustrates the front part of the vehicle 10 in a top view. The field of vision 210 is associated with a viewpoint 21 which corresponds to the viewpoint from which a driver is supposed to look at the road in front of him when driving the vehicle 10. This viewpoint 21 is for example positioned in the middle of the driver's seat (front left in the direction of travel of the vehicle 10 according to the particular example of the [Fig.2]), at the location of the driver's head if the driver were sitting in the driver's seat. Viewpoint 21 is for example positioned in the center of a headrest resting on the driver's seat when the seat is equipped with such a headrest.

[0046] The field of vision 210 extends for example around a main vision axis 211, and covers an area between an upper vertical limit (forming for example an angle of 15° with the axis 211 from the point of view 21), a lower vertical limit (forming for example an angle of 15° with the axis 211 from the point of view 21), a right lateral limit (forming for example an angle of 20 or 25° with the axis 211 from the point of view 21) and a left lateral limit (forming for example an angle of 25 or 30° with the axis 211 from the point of view 21).

[0047] A graphic object 2100 of a floating image is advantageously projected or displayed within the field of vision 210, to ensure that the driver is looking at the road or the environment in front of the vehicle 10 according to this field of vision 210.

[0048] A floating image comprising the graphic object is advantageously collimated on an image plane 212 perpendicular to the axis 211 and positioned at a particular distance from the viewpoint 21 along the axis 211, such a distance being advantageously greater than or equal to 3.5 m, for example equal to 3.5, 4 or 4.5 m.

[0049] The graphic object 2100 depends for example on the type of information projected onto the surface 101. The graphic object 2100 corresponds for example to a representation of a warning sign, of a vehicle, for example a car, or of a pedestrian, an arrow indicating the direction to follow. The graphic object 2100 is for example semi-transparent to allow the driver to see the road environment through this graphic object 2100.

[0050] When the display of a floating image is intended to alert the driver of the vehicle 10 to a potential danger, the graphic object is for example displayed at the location of an object detected in front of the vehicle 10, to draw the driver's attention to this detected object. The graphic object 2100 corresponds to a virtual element added by incrustation or superposition of this virtual element on an element of the real world.

[0051] The movement of the graphic object 2100 follows for example the movement of an object detected in front of the vehicle 10, the movement of the detected object corresponding for example to the movement of the detected object, where appropriate, relative to the movement of the vehicle 10. According to a variant, the graphic object 2100 is initially displayed in a first position before following the movement of the detected object.

[0052] [Fig. 3] schematically illustrates the head-up display device 3 on board the vehicle of [Fig. 1], according to a particular and non-limiting exemplary embodiment of the present invention.

[0053] The head-up display device 3 allows the incrustation of virtual objects in the field of vision of the driver of the vehicle 10, for example on a surface of the windshield. breeze 100, so as to superimpose the virtual objects on the reality of a road scene.

[0054] The head-up display device 3 comprises a control unit 301 configured for processing data received from sensors of the vehicle 10 and / or from systems embedded in the vehicle 10 and / or from remote devices connected to the vehicle 10. The control unit 301 is advantageously configured to generate the floating images from the received data.

[0055] The control unit 301 advantageously comprises one or more processors of the CPU (Central Processing Unit) and / or GPU (Graphics Processing Unit) type associated with a memory. The control unit 301 corresponds for example to one or more computers of the on-board system of the vehicle 10, for example by the computer of the infotainment system, called IVI (In-Vehicle Infotainment) computer of the vehicle 10.

[0056] The head-up display device 3 comprises a projector 302 configured to project at least two light beams, each carrying data representative of a floating image obtained from the control unit 301.

[0057] According to the particular embodiment, the projector 302 comprises a single projection means.

[0058] According to the particular and non-limiting exemplary embodiment, the projector 302 comprises more than one projection means, each configured to project a light beam.

[0059] For example, as illustrated in [Fig.3], a first projection means of the projector 302 is configured to project a first floating image II and a second projection means of the projector 302 is configured to project a second floating image 12.

[0060] According to a particular and non-limiting exemplary embodiment, the projector 302 is configured to project several beams of coherent light with controlled polarization.

[0061] A beam of light is called a coherent light beam if this light beam is separable into two mutually coherent light waves, that is to say two light waves which give rise to an interference pattern stable enough to be detected.

[0062] Light is an electromagnetic wave, that is to say it is described by signals (electric and magnetic fields) which oscillate in space and time. The polarization of light is a property that vector waves have of presenting a privileged distribution of the orientation of the vibrations which compose them. Electromagnetic waves, such as light, thus have polarization properties and the privileged distribution of the orientation of the vibrations which compose them is called the state of polarization. In a polarized electromagnetic wave (linearly), the electric field and the magnetic field oscillate simultaneously in directions perpendicular to each other. By convention, the polarization of light describes the vibration of the electric field and when the wave is linearly polarized, this field oscillates in a single direction. When a wave consists of two components polarized at 90° to each other, and also 90° out of phase with each other, then its polarization appears to rotate around the axis of propagation of the wave. In this case, we speak of circular or elliptical polarization (when the two components do not have the same intensity).Circular and linear polarizations are special cases of elliptical polarization (depending on whether the two components are equal, or on the contrary, the second component is zero; and moreover, a wave of elliptical polarization can be seen as the sum of a circular polarization and a linear polarization. A light beam is said to be polarized when the polarization is identical at every point of the image represented by this light beam, that is to say when the emitted wavefront is identical at every point of the image.

[0063] According to a particular and non-limiting exemplary embodiment, the projector 302 is of the “emissive” type and corresponds, for example, to a laser scanner comprising at least one laser diode, for example three laser diodes to generate three different colors, for example RGB (one diode per RGB color).

[0064] A laser scanner advantageously comprises a diffuser and a scanning unit generating a light beam, which light beam scans the rear face of the diffuser. The scanning unit comprises, for example, a light beam generator associated with a matrix of micromirrors, called DMD (from the English “Digital Micro-mirror Device”) configured to orient the light beam on the rear face of the diffuser. The DMD comprises a matrix of movable mirrors produced in the form of a microelectromechanical system, called MEMS (from the English “Micro-Electro-Mechanical System”).

[0065] According to a particular and non-limiting exemplary embodiment, the projector 302 is of the “light modulation” type and corresponds for example to a display screen, for example an LCD type screen (from the English “Liquid Crystal Display” or in French “Display à cristals liquide”), for example a TFT type screen (from the English “Thin-Film Transistor” or in French “Transistor en film mince”), or an OLED type screen (from the English “Organic Light-Emitting Diode” or in French “Diode électroluminescente biologique”).

[0066] The light beams projected by the projector 302 are shifted in time so that the eye of a driver of the vehicle 10 distinguishes the floating images represented by these light beams without flickering. Typically, the frequency display frequency F of floating images is at least in the order of 50-60 Hz.

[0067] The head-up display device comprises an optical processing means 30 configured to redirect each light beam projected by the projector 302 towards an image plane.

[0068] According to a particular and non-limiting exemplary embodiment, the optical processing means 30 comprises a first polarization means 303 of the polarizer type, which is coupled to the projector 302 and synchronized with a display frequency of the projector 302 to produce polarized images which follow one another in time.

[0069] A polarizer is an optical instrument that selects a preferential polarization direction in an incident light wave, thereby defining a polarization state of this light wave. The polarization means 303 may be configured to polarize each light beam projected by the projector 302 in a unique polarization state, that is to say to associate a unique preferential polarization direction with each projected light beam.

[0070] According to a particular and non-limiting exemplary embodiment, the first polarization means 302 comprises a combination of linear polarizers and spatial light modulators or SLMs (from the English "Spatial Light Modulator") or ferroelectric modulators. The modulation mechanism of a spatial light modulator (SLM) is based on a method which modifies the properties of the modulation material and on the manner in which the spatial field of an incident light beam is modified. Various methods including mechanical, electro-optical, thermo-optical and magneto-optical effects can be used to modify the properties of the modulation material of a spatial light modulator which interacts with incident light and transforms its spatial field distribution.One of the most commonly used modulation mechanisms today is the electro-optical spatial light modulator containing liquid crystals as the modulation material (LC-SLM).

[0071] A linear polarizer allows the propagation of waves of a light beam which propagate in a particular propagation direction. This is sometimes referred to as a linear filter. A linear polarizer can thus favor a wave propagation direction located in a horizontal, vertical or intermediate plane depending on the angle of the polarizer. Different types of linear polarizers are available, including dichroic, reflection, double refraction and beam splitting polarizers.

[0072] The characteristics that generally define a linear polarizer are its transmission and absorption capabilities. A transmission axis, which often varies depending on the polarizer class, determines how much light can pass through a barrier. The absorbing axis does not allow light to pass through the barrier. Two polarizers can be used at 90° to each other, so that light don't go to the other side of the barrier.

[0073] Dichroic polarizers can absorb polarized light waves oriented in a particular direction. Such varieties of linear polarizers can be made of polyvinyl alcohol or a laminated polymer film.

[0074] According to a particular and non-limiting exemplary embodiment, the optical processing means 30 comprises a multi-focal holographic lens 304. The lens 304 is sensitive to the polarization states of light beams, that is to say that it reflects a polarized light beam with a particular focal length which depends on the polarization state of this polarized light beam. Each polarized light beam is reflected by a reflective element of the lens 304 with a particular focal length.

[0075] According to a particular and non-limiting exemplary embodiment, the reflective elements of the lens 304 are blades oriented at the Brewster angle (https: / / fr.wikipedia.org / wiki / Angle_de_Brewster) relative to the polarized light beams. At the Brewster angle, p-polarized light (parallel to a plane of incidence associated with an incident polarized light beam) is not reflected and a majority (more than 80%) of the s-polarized light (perpendicular to the plane of incidence) is transmitted. An example of the construction of a multi-focal holographic lens is described in the article by K. Hong et al. (“Full-color lens-array holography optical element for three-dimensional optical see-through augmented reality”, January 2, 2004, vol. 39, no. 1, OPTICS LETTERS). Each lens plate 304 is configured to reflect an incident polarized light beam at a particular focal length.This blade of the lens 304 is determined according to the state of polarization of the incident polarized light beam. Each incident polarized light beam therefore “sees” a single particular blade of the lens 304 which is determined according to its state of polarization.

[0076] According to a particular and non-limiting exemplary embodiment, the first polarization means 303 can polarize each light beam in a single polarization state and a single reflective element of the lens 304 reflects the light beam with a single focal length determined by the polarization state of the light beam. The optical processing means 30 is then configured so that each polarized light beam is reflected with a single focal length by a particular reflective element of the lens 304 and that all the floating images are displayed on the same image plane. The head-up display device then operates in single-plane display mode.

[0077] According to a particular and non-limiting exemplary embodiment, the lens 304 can reflect incident polarized light beams with different particular focal lengths so that the floating images represented by data carried by these light beams are displayed on image planes located at different distances from the point of view 21. The head-up display device then operates in multi-plane mode.

[0078] According to a particular and non-limiting exemplary embodiment, the blades of the lens 304 are glass blades and the Brewster angle is of the order of 57°.

[0079] According to a particular and non-limiting exemplary embodiment, the reflective elements of the lens 304 are thin films of material sensitive to the polarization state of an incident polarized light beam.

[0080] According to a particular and non-limiting exemplary embodiment, the lens 304 is also sensitive in angle of incidence and the first polarization means 303 is configured to define optical paths so that the incident polarized light beams arrive at the lens 304 with different particular angles of incidence. Thus, the reflective elements of the lens 304 are selected according to the angles of incidence of these incident polarized light beams.

[0081] According to a particular and non-limiting exemplary embodiment, the optical processing means 30 comprises a second polarization means 305 which is synchronized with the display frequency of the projector 302 to produce floating images which follow one another in time. The second polarization means 305 is configured to polarize the reflected light beams in the same propagation direction for displaying the floating images on image planes defined from the focal distances fixed by the lens 304. The second polarization means 305 makes it possible to maintain the same perception of the floating images by the driver of the vehicle 10. It also makes it possible to choose an optimal polarization with respect to the reflection of the windshield 100.

[0082] According to a particular and non-limiting exemplary embodiment, the head-up display device may comprise several orientable mirrors.

[0083] The display system comprises a human-machine interface, called HMI, configured to select either the single-plane display mode or the multi-plane mode.

[0084] According to a particular and non-limiting exemplary embodiment, the display mode is selected by an action of a user of the vehicle 10 on a human-machine interface, called HMI.

[0085] According to a particular and non-limiting exemplary embodiment, the HMI can be actuated by the user of the vehicle 10 to switch from the single-plane display mode to the multi-plane mode or conversely from the multi-plane mode to the single-plane display mode.

[0086] According to a particular and non-limiting exemplary embodiment, a first action on the HMI allows the selection of the single-plane display mode and a second action on the HMI allows the selection of the multi-plane mode.

[0087] According to a particular and non-limiting exemplary embodiment, the HMI is a touch screen comprising at least one touch zone allowing the selection of the single-plane or multi-plane display mode.

[0088] According to a particular and non-limiting example of embodiment, the HMI is a button or a wheel, for example positioned at the level of the dashboard of the vehicle 10.

[0089] A process for controlling the head-up display device 3 will now be described.

[0090] In a first operation, a display mode of the data representative of each floating image is selected via the HMI from among the single-plane display mode and the multi-plane display mode.

[0091] In a second operation, the behavior of the projector 302 and / or the behavior of the optical processing means 30 are adapted according to the display mode selected as explained previously.

[0092] According to a particular and non-limiting exemplary embodiment, the behavior of the projector 302 is adapted by only projecting certain light beams when the single-plane display mode is selected.

[0093] According to a particular and non-limiting exemplary embodiment, the behavior of the optical processing means is adapted by adapting the polarization direction of each light beam projected by the projector 302 through the polarization means 303.

[0094] For example, the polarization means 303 can determine particular angles of incidence of the light beams projected by the projector 302 onto the lens 304. The head-up display device can then operate either in single-plane display mode or in multi-plane display mode depending on the values ​​of these angles of incidence.

[0095] For example, when the selected display mode is the single-plane display mode, the polarization means 303 can be configured so that the polarization directions of all the light beams are determined so that all the floating images are displayed on the same image plane.

[0096] For example, when the selected display mode is the multi-plane display mode, the polarization means 303 can be configured so that the polarization directions of the light beams are determined so that each floating image is displayed on a different image plane positioned at a predetermined distance from the viewpoint 21.

[0097] For example, linear or dichroic polarizers or light modulators which can form the first polarization means 303 can be configured to determine the polarization directions of the light beams projected by the projector 302.

[0098] According to a particular and non-limiting exemplary embodiment, the optical processing means comprising several orientable mirrors, the behavior of the optical processing means comprises the orientation of at least one of the mirrors to redirect at least one light beam projected by the projector 302 in a particular direction so that the floating images are displayed either on the same image plane (single-plane display mode) or on several image planes (multi-plane display mode) depending on the selected display mode.

[0099] In a third operation, graphic objects of the displayed floating images are adapted to the or each of the image planes according to the selected display mode.

[0100] According to a particular and non-limiting exemplary embodiment, the adaptation of the graphic objects of the floating images comprises the resizing of these graphic objects, a modification of the light intensity with which these objects are displayed or a repositioning of at least one of these graphic objects on an image plane.

[0101] According to a particular and non-limiting exemplary embodiment, when the floating images are previously displayed on several image planes and the single-plane display mode is selected, the adaptation of the graphic objects of the floating images comprises a superposition of the graphic objects of the floating images on a single image plane.

[0102] According to a particular and non-limiting exemplary embodiment, when the floating images are previously displayed on the same image plane and the multi-plane display mode is selected, the adaptation of the graphic objects of the floating images comprises a display of the graphic objects of each floating image on a single image plane.

[0103] [Fig.4] schematically illustrates a device 4 configured to control a head-up display device of [Fig.3], according to a particular and non-limiting exemplary embodiment of the present invention.

[0104] The device 4 corresponds for example to a device on board the vehicle 10, for example a computer and / or the control unit 301.

[0105] The device 4 is for example configured for the implementation of all or part of the operations described with regard to figures 1 to 3 and / or the steps of the method described with regard to [Fig.5]. Examples of such a device 4 include, but are not limited to, on-board electronic equipment such as an on-board computer of a vehicle, an electronic calculator such as an ECU (“Electronic Control Unit”), a smartphone, a tablet, a laptop. The elements of the device 4, individually or in combination, can be integrated in a single integrated circuit, in several integrated circuits, and / or in discrete components. The device 4 can be produced in the form of electronic circuits or software (or computer) modules or a combination of electronic circuits and software modules.

[0106] The device 4 comprises one (or more) processor(s) 40 configured to execute instructions for carrying out the steps of the method and / or for executing the instructions of the software(s) embedded in the device 4. The processor 40 may include integrated memory, an input / output interface, and various circuits known to those skilled in the art. The device 4 further comprises at least one memory 41 corresponding for example to a volatile and / or non-volatile memory and / or comprises a memory storage device which may comprise volatile and / or non-volatile memory, such as EEPROM, ROM, PROM, RAM, DRAM, SRAM, flash, magnetic or optical disk.

[0107] The computer code of the embedded software(s) comprising the instructions to be loaded and executed by the processor is for example stored in the 4L memory.

[0108] According to various particular and non-limiting embodiments, the device 4 is coupled in communication with other similar devices or systems and / or with communication devices, for example a TCU (from the English “Telematic Control Unit” or in French “Telematic Control Unit”), for example via a communication bus or through dedicated input / output ports.

[0109] According to a particular and non-limiting exemplary embodiment, the device 4 comprises a block 42 of interface elements for communicating with external devices, for example a remote server or the “cloud”, other nodes of the ad hoc network. The interface elements of the block 42 comprise one or more of the following interfaces: - RF radio frequency interface, for example Bluetooth® or Wi-Fi®, LTE (Long-Term Evolution), LTE-Advanced; - USB interface (from the English “Universal Serial Bus” or “Universal Serial Bus” in French); - HDMI interface (from the English “High Definition Multimedia Interface” or “High Definition Multimedia Interface” in French); - LIN interface (from the English “Local Interconnect Network”).

[0110] According to another particular and non-limiting exemplary embodiment, the device 4 comprises a communication interface 43 which makes it possible to establish communication with other devices (such as other computers of the on-board system) via a communication channel 430. The communication interface 43 corresponds for example to a transmitter configured to transmit and receive information and / or data via the communication channel 430. The communication interface 43 corresponds for example to a wired network of the CAN (Controller Area Network) type, CAN FD (Controller Area Network Flexible Data-Rate), FlexRay (standardized by the ISO 17458 standard) or Ethernet (standardized by the ISO / IEC 802-3 standard).

[0111] According to a particular and non-limiting exemplary embodiment, the device 4 can provide output signals to one or more external devices, such as a display screen 440, one or more speakers 450 and / or other peripherals 460 (for example the projector 302) via output interfaces 44, 45 and 46 respectively. According to a variant, one or other of the external devices is integrated into the device 4.

[0112] [Fig.5] illustrates a flowchart of the different steps of a method for controlling a head-up display device on board a vehicle of [Fig.l], according to a particular and non-limiting exemplary embodiment of the present invention.

[0113] The method is for example implemented by a device on board the vehicle 10, for example by one or more processors on board the vehicle 10 (for example the device 4 of [Fig.5]) and / or by the display system described above.

[0114] In a first step 51, a display mode of the data representative of each floating image is selected via the HMI from among the single-plane display mode and the multi-plane display mode.

[0115] In a second step 52, the behavior of the projector 302 and / or the behavior of the optical processing means 30 are adapted according to the display mode selected as explained previously.

[0116] In a third step 33, graphic objects of the displayed floating images are adapted on the or each of the image planes according to the selected display mode.

[0117] Of course, the present invention is not limited to the exemplary embodiments described above but extends to a method for controlling a head-up display device on board a vehicle which would include secondary steps without thereby departing from the scope of the present invention. The same would apply to a device configured for implementing such a method.

[0118] The present invention also relates to a vehicle, for example a motor vehicle or more generally an autonomous land-based motor vehicle, comprising the device 4 for controlling the head-up display device 3 or a display system described above.

Claims

Claims

1. Method for controlling a head-up display device on board a vehicle (10), said head-up display device comprising a projector configured to project at least two light beams each carrying data representative of a floating image, and an optical processing means configured to redirect each light beam to an image plane, said method comprising the following steps: - selection (51) of a mode for displaying the data representative of each floating image from among a single-plane display mode and a multi-plane display mode, said single-plane display mode defining a display mode in which the projector and / or the optical processing means are configured to redirect said at least one light beam to a single image plane and,said multi-plane display mode defining a display mode in which the projector and / or the optical processing means are configured to redirect the light beams towards image planes positioned at different distances from a point of view of the vehicle; - adaptation (52) of a behavior of the projector and / or a behavior of the optical processing means according to the selected display mode; and - adaptation (53) of graphic objects of the floating images displayed on the or each of the image planes according to the selected display mode.,

2. Method according to claim 1, in which the display mode is selected by an action of a user of the vehicle on a human-machine interface, called HMI.

3. Method according to one of the preceding claims, in which the optical processing means comprising several orientable mirrors, the behavior of the optical processing means comprises an orientation of at least one of the mirrors to redirect at least one light beam projected by the projector in a particular direction so that the floating images are displayed either on the same image plane or on several image planes depending on the selected display mode.

4. Method according to one of the preceding claims, in which the adaptation of the graphic objects of the floating images comprises the resizing of at least one of said graphic objects, a modi- adjustment of the light intensity with which at least one of said graphic objects is displayed or a repositioning of at least one of said graphic objects on an image plane.

5. Method according to one of the preceding claims, in which when the floating images are previously displayed on several image planes and the single-plane display mode is selected, the adaptation of the graphic objects of the floating images comprises a superposition of the graphic objects of the floating images on a single image plane.

6. Device (4) for controlling a head-up display device on board a vehicle (10), said device (4) comprising a memory (41) associated with at least one processor (40) configured for implementing the steps of the method according to any one of the preceding claims.

7. Display system on board a vehicle (10), said display system comprising: - a head-up display device comprising a projector configured to project at least two light beams each carrying data representative of a floating image and an optical processing means configured to redirect each light beam towards an image plane;- a human-machine interface, called HMI, configured to select either a single-plane display mode or a multi-plane mode, said single-plane display mode defining a display mode in which the projector and / or the optical processing means are configured to redirect said at least one light beam towards a single image plane and, said multi-plane display mode defining a display mode in which the projector and / or the optical processing means are configured to redirect the light beams towards image planes positioned at different distances from a point of view of the vehicle; - a device for controlling the head-up display device according to claim 6.;

8. Computer program comprising instructions for implementing the method according to any one of claims 1 to 5, when these instructions are executed by a processor.

9. A computer-readable recording medium on which is recorded a computer program comprising instructions for carrying out the steps of the method according to one of claims 1 to 5.

10. A vehicle (10) comprising a display system according to claim 7 or a device according to claim 6.

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