Head-up display device

Abstract

The present invention relates to a head-up display device suitable for being integrated in a vehicle (10) for displaying information intended for one or more users of a vehicle (10), the device comprising: a panel (20) having a useful surface (21), at least a portion of which can be positioned in front of one or more users of the vehicle (10), the panel (20) having an opacity which is capable of varying between transparent and opaque on the basis of an activation command, a reflector element covering the useful surface (21) of the panel (20), the reflector element being at least partially reflective, and an information transmission unit (24), the transmission unit (24) being capable of transmitting at least one light beam in the direction of the reflector element such that the reflection of the light beam on the reflector element forms at least one useful image in an observation window for a user of the vehicle (10).

Description

[0001] DESCRIPTION

[0002] TITLE: Head-up display device

[0003] The present invention relates to a head-up display device. The present invention also relates to a vehicle comprising such a head-up display device.

[0004] Vehicles, particularly automobiles, are equipped with control devices, also called instrument clusters or dashboards, to provide the driver with information useful for driving and operating the vehicle. To this end, the instrument cluster includes the vehicle's instruments, some of which are mandated by law.

[0005] In a motor vehicle, the instrument panel is traditionally integrated into the dashboard below the windshield, behind the steering wheel. Typically, such an instrument panel is positioned at least -15° from the direction of vision of an average driver looking at the road, approximately 50 centimeters from their eyes. This forces the driver to take their eyes off the road to view the instrument panel, reducing alertness and increasing eye strain due to the constant effort of visual accommodation required.

[0006] To allow the viewing of useful information in a safer manner, it is known to use head-up displays that relay some information from the instrument panel to the driver.

[0007] However, such displays take up additional space in the vehicle, redundant with the instrument panel, and some are quite bulky. Furthermore, these displays only allow the useful image to be viewed within a limited viewing window (or "eyebox").

[0008] Furthermore, the visibility of the image displayed by these screens depends on ambient light. Therefore, in bright sunlight, the image visibility is often reduced because the projection screen's brightness is insufficient. One possibility would be to increase the screen's brightness. However, this would lead to increased energy costs and heat generation. Moreover, projection screens have limited power output.

[0009] An alternative is to replace mechanical dashboard instruments with digital ones. For this purpose, control devices in the form of screens are available. The trend is to position such control devices increasingly higher in the driver's field of vision in order to reduce the viewing angle (or "look-down angle") of the dashboard instruments.

[0010] However, such control devices then obscure part of the vehicle's windshield, and in particular part of the driver's field of vision, which is not optimal in terms of driving comfort and safety.

[0011] Therefore, there is a need for a vehicle head-up display system that allows useful driving information to be displayed in a comfortable viewing window for the driver without affecting driving safety.

[0012] For this purpose, the present description relates to a head-up display device designed to be integrated into a vehicle to display information to one or more vehicle occupants, the device comprising:

[0013] - a sign having a usable surface area, at least part of which is suitable for positioning opposite one or more vehicle users, the sign having an opacity that can vary between transparent and opaque depending on an activation command,

[0014] - a reflective element covering the effective surface of the panel, the reflective element being at least partially reflective, and

[0015] - an information emission unit, the emission unit being capable of emitting at least one light beam in the direction of the reflector element so that the reflection of the light beam on the reflector element forms at least one useful image in an observation window of a vehicle user.

[0016] According to other advantageous aspects, the head-up display device includes one or more of the following features, taken individually or in all technically possible combinations:

[0017] - the panel also has its own color which varies depending on the activation command, preferably the color of the panel being black when the panel is opaque;

[0018] - the activation command is triggered by a vehicle user;

[0019] - the activation command is triggered automatically depending on environmental conditions;

[0020] - the activation command is defined automatically based on a measurement of the brightness at the level of the useful surface of the panel, the measurement having been carried out by at least one sensor integrated into the vehicle;

[0021] - the activation command is defined automatically based on a prior detection carried out by at least one sensor in the vehicle, the prior detection being relative to a vehicle user; - the prior detection includes the detection or not of the wearing of sunglasses by a vehicle user;

[0022] - the panel is made of a switchable material, for example a photochromic material or an electrochromic material;

[0023] - the panel is made up of several portions, the variation of opacity of the panel being implemented on one or more portions of the panel and / or in the form of a gradient, depending on the activation command;

[0024] - the device is designed to be integrated into the vehicle's dashboard, the panel being designed to be fixed directly to the vehicle's dashboard;

[0025] - the vehicle includes a windscreen, the panel being formed in a part of the windscreen;

[0026] - the windscreen comprises a transparent surface, a screen-printed area and an intermediate area, the screen-printed area surrounding the transparent surface, the screen-printed area comprising a lower part, the intermediate area extending from the lower part, the intermediate area forming the panel;

[0027] - the device includes pillars connected to the lateral parts of the screen-printed area of ​​the windscreen, the intermediate area comprising a band projecting from the lower part of the screen-printed area and extending over substantially the width of the transparent surface with the exception of the ends of the lower part of the screen-printed area which are clear, so as to clear the visibility of the environment at the level of the vehicle pillars;

[0028] - the emission unit is designed to emit, in the direction of the reflector element, a light beam polarized according to a principal polarization, called the incident beam, the incident beam arriving on the reflector element with an angle of incidence and defining with the reflector element a plane of incidence, the principal polarization being a polarization contained in the plane of incidence, called P polarization, the reflector element being optimized so as to have a greater reflectivity, over a range of angles of incidence including the angle of incidence, for a light of P polarization than a non-optimized reflector element.

[0029] This description also applies to a vehicle in which a device as described above is integrated.

[0030] Other features and advantages of the invention will become apparent from the following description of embodiments of the invention, given by way of example only, and with reference to the drawings which are: - figure 1, a schematic representation of an example of a vehicle passenger compartment in which a head-up display device is integrated according to a first integration method,

[0031] - Figure 2, a schematic representation of an example of a head-up display device,

[0032] - Figure 3, a schematic representation of another example of a head-up display device,

[0033] - Figure 4, a schematic representation of an example of a passenger compartment in which a head-up display device is integrated according to a second integration method, and

[0034] - figure 5, a schematic representation of a windscreen (visible face from the outside) of the vehicle according to the second integration method.

[0035] A vehicle 10 is illustrated by figure 1.

[0036] In this example, the vehicle 10 includes, in a passenger compartment 11, a windscreen 12, a dashboard 14, pillars 15 and a head-up display device 16.

[0037] Vehicle 10 is, for example, a land, air, or sea vehicle. A land vehicle is, for example, a motor vehicle (Figure 1), a railway vehicle, or a two-wheeler.

[0038] The dashboard 14 is defined as a surface extending across the entire width of the vehicle 10, below the windscreen 12 and above the feet of the driver 18 and, where applicable, the front passenger.

[0039] The pillars 15 are connected to the windscreen 12 and to the roof of the vehicle 10.

[0040] First method of integrating the head-up display device 16

[0041] In the integration mode of Figure 1, the head-up display device 16 is integrated into the dashboard 14 of the vehicle 10.

[0042] The term "integrated" means that the head-up display 16 is properly incorporated into the dashboard 14. Such integration was, for example, achieved during the design of the dashboard 14 (during the industrialization phase of the vehicle 10). The head-up display 16 is therefore different from a retrofitted device that would simply have been placed in the vehicle 10 without specific integration into the dashboard 14.

[0043] The head-up display device 16 is designed to display information to one or more users of the vehicle 10, for example, vehicle control information 10, including all the vehicle 10's on-board instruments.

[0044] On-board instruments are indicators or warning lights that inform the driver 18 of a vehicle 10 about driving parameters (speed, acceleration, temperature, etc.) and the operation of the vehicle 10, in particular the engine of the vehicle 10. For a motor vehicle, on-board indicators include, for example, at least a tachometer, a speedometer, a fuel gauge and a coolant temperature indicator.

[0045] Optionally, the head-up display 16 is also suitable for displaying useful driving information such as navigation (maps, positions, directions); traffic conditions (traffic jams, roadworks), or more generally driver assistance systems (ADAS for "Advanced Driving Assistant Systems").

[0046] Optionally, the head-up display 16 is also suitable for displaying other information such as multimedia services, or information relating to the vehicle's climate control.

[0047] Advantageously, the head-up display 16 is the only element integrated into the vehicle 10 that displays the instrument panel. The vehicle 10 is thus devoid of integrated mechanical instrument panels or other integrated digital means of displaying the instrument panel.

[0048] Advantageously, the head-up display device 16 is configured to switch on automatically when the ignition is switched on in the vehicle 10 (i.e., when the vehicle engine is started) and to switch off automatically when the ignition is switched off in the vehicle 10 (engine stopped).

[0049] As illustrated by Figure 2, the head-up display device 16 comprises a panel 20, a reflector element 22 and a vehicle control information emission unit 24 10.

[0050] The panel 20 has a usable surface 21, at least part of which is suitable for being positioned opposite one or more users of the vehicle 10.

[0051] For example, sign 20 is positioned opposite the upper body (torso, head) of a driver 18 in the driving position. Alternatively, sign 20 is positioned opposite a passenger (upper body).

[0052] In the example illustrated by Figure 1, the panel 20 is a blade attached to the dashboard 14 and projecting out from the dashboard 14. Alternatively, the panel 20 is a panel attached to the dashboard 14 and flush with the dashboard 14 (or a surface of the dashboard 14).

[0053] In one implementation example, the usable surface 21 extends across the entire width of the dashboard 14, i.e., opposite the driver's seat and the front passenger seat in the case of a motor vehicle. The usable surface 21 is preferably flat, which reduces distortions and provides a larger viewing window than a concave surface. Alternatively, all or at least part of the usable surface 21 is concave.

[0054] Panel 20 has an opacity, called variable opacity, which varies between transparent and opaque depending on an activation command.

[0055] The term "opaque" refers to zero transparency. The term "transparent" refers to zero opacity. Thus, depending on the activation command, the opacity of panel 20 can be either zero (transparent), intermediate (semi-opaque), or opaque.

[0056] For example, the activation command is a light beam emitted by a light source (e.g., visible or ultraviolet), a temperature, or an electrical potential difference applied to panel 20.

[0057] In one implementation example, the activation command is triggered by a user of vehicle 10. For example, a human-machine interface is connected to a control unit capable of generating the activation command to the panel 20 based on a user command received via the human-machine interface.

[0058] In addition or as an alternative, the activation command is triggered automatically based on environmental conditions (brightness, UV radiation, temperature...).

[0059] Preferably, panel 20 is made of a switchable material. A switchable material is a material whose properties (at least opacity, and possibly hue) are capable of changing reversibly.

[0060] A switchable material is, for example, a switchable passive material. For instance, a switchable passive material is a photochromic material or a thermochromic material.

[0061] The switchable material is, for example, an electrically switchable active material. For example, the electrically switchable active material is chosen from:

[0062] - an electrochromic material,

[0063] - a PDLC material (from the English Polymer Dispersed Liquid Crystal, translated into French as cristallis liquide disperses par polymer),

[0064] - a PNLC material (from the English Polymer Network Liquid Crystal, translated into French as cristalx liquide à réseau polymer),

[0065] - an SPD material (from the English Suspended Particle Device), - an electrophoretic ink, and

[0066] - a GHLC material (from the English Guest-Host Liquid Crystal, translated into French as guest-host liquid crystals).

[0067] As an optional addition, the switchable material is a chromogenic material. A chromogenic material is a material capable of producing a pigment.

[0068] Preferably, panel 20 also has its own tint which varies according to the activation command.

[0069] Advantageously, the tint of panel 20 is black when panel 20 is opaque. This allows for useful images with better contrast.

[0070] In one example, panel 20 is divided into (or formed from) several portions. The portions are either identical or of different sizes. The portions are typically continuous. The opacity variation of panel 20 is implemented on one or more portions of panel 20 and / or in the form of a gradient, depending on the activation command.

[0071] For example, at least some portions have different heights and / or widths.

[0072] For example, the sections extend in front of the driver and / or the front passenger.

[0073] For example, the sections extend in width in front of both the driver and the front passenger, but with different heights depending on whether they are positioned in front of the driver or in front of the front passenger.

[0074] For example, the activation command is chosen by a vehicle user, who decides on the portions and / or the gradient.

[0075] Alternatively, the activation command is set automatically based on a prior detection carried out by a sensor in the vehicle.

[0076] Preferably, the preliminary detection is related to a user of the vehicle.

[0077] For example, a sensor can detect the size of a user, and the portions for which the variation of opacity is implemented depend on the size detected (for example, more or fewer portions vertically depending on the size detected).

[0078] For example, a presence sensor can detect the presence of occupants at the front of the vehicle, for example the driver and / or front passenger.

[0079] The reflective element 22 covers the useful surface 21 of the panel 20.

[0080] The reflective element 22 is at least partially reflective.

[0081] The reflecting element 22 is, for example, a coating or treatment (for example, obtained by physical or chemical deposition) or a film (for example, laminated or held in place by electrostatic effect). The emitting unit 24 is adapted to emit at least one light beam in the direction of the reflecting element 22 such that the reflection of the light beam by the reflecting element 22 forms at least one useful virtual image in an observation window of the driver 18 in the driving position.

[0082] The light beam is, for example, in the visible wavelength range (380 nanometers to 700 nanometers). The resulting image allows the driver 18 to view vehicle control information 10.

[0083] Preferably, the emission unit 24 includes at least one screen 40 on which an image is displayed. The at least one useful image is then a virtual image IM of the image displayed on the screen 40. Such a virtual image IM is obtained by reflection of the beam from the screen 40 onto the reflector element 22 (due to the semi-reflective property of the reflector element 22).

[0084] The 40 screen is, for example, a liquid crystal display (LCD for "liquid crystal display").

[0085] Advantageously, the head-up display device 16 is devoid of optics in the path of the light beam between the emission unit 24 and the reflector element 22, which allows for a gain in compactness and does not restrict the observation window.

[0086] An example of the operation of the head-up display device 16 integrated into the vehicle 10 will now be described.

[0087] Advantageously, the head-up display device 16 is switched on automatically when the ignition is switched on in the vehicle 10 and is switched off automatically when the ignition is switched off in the vehicle 10.

[0088] The opacity, and where applicable the tint, of panel 20 is set according to the activation command. Optionally, the application of the opacity variation to one or more portions of panel 20 and / or in the form of a gradient, is also controlled by the activation command. The activation command is either automatic or triggered by a user.

[0089] During driving, the emission unit 24 sends information in the form of a light beam towards the reflector element 22 which then forms a useful image including information useful for driving the vehicle 10.

[0090] Thus, the head-up display 16 allows the display of useful driving information (control information, navigation, traffic conditions) without affecting driving safety, since the windshield 12 is not obscured. Such a head-up display 16 is compact and easily integrated into the dashboard 14 of the vehicle 10. Furthermore, such a head-up display 16 allows the useful image to be viewed in a larger, and therefore more comfortable, viewing window (eyebox) than with a standard head-up display.

[0091] Furthermore, the variable opacity of panel 20 allows the contrast of the display image to be adjusted, for example, according to user preferences or environmental conditions. The ability to project the display image onto an opaque or semi-opaque panel provides better contrast compared to a transparent panel. This makes it possible to reduce the brightness of the emission unit 24 (for example, from 12,000 nits, the current minimum standard for head-up displays, to 6,000 nits or less, a reduction by a factor of 2), which simplifies the implementation of the head-up display device 16, reduces heat generation, and results in energy savings compared to a transparent panel.

[0092] The following describes, with reference to Figure 3, an embodiment of the head-up display device which optionally complements the embodiment described previously.

[0093] In this embodiment, the reflector element 22, also called a reflective polarizer, is an element designed to reflect an incident light beam F, having a given range of wavelengths, depending on the angle of incidence Oj of the incident beam F on the reflector element 22 and the polarization of said incident beam F r

[0094] The given range of wavelengths of the incident beam F, belongs, for example, to the visible domain (380 nanometers to 700 nanometers).

[0095] The angle of incidence Oj of the incident beam F| is the angle between the beam axis and the normal N to the reflecting element 22 at the point of incidence P| of the incident beam F| on the reflecting element 22. The axis of the incident beam F and the normal N to the reflecting element 22 at the point of incidence P define a plane of incidence. In the example illustrated by Figure 3, the plane of incidence is the plane shown in the figure. In particular, the reflecting element 22 is designed to reflect the incident beam F, forming a useful virtual image observable from an observation window (corresponding to a useful beam Fu).

[0096] In what follows, a linear polarization contained in the plane of incidence is also called P-polarization, and a linear polarization perpendicular to the plane of incidence is also called S-polarization.

[0097] The reflector element 22 is optimized to reflect P-polarized light.

[0098] Preferably, the reflector element 22 has greater reflectivity, over a range of incidence angles and wavelengths, for P-polarized light than for light of a different polarization (S-polarized, circular, elliptical). Alternatively (particularly on an industrial scale), the reflector element 22 has optimized reflectivity for P-polarized light compared to reflection from a non-specifically optimized reflector element. However, the reflectivity of the reflector element 22 remains greater, over a range of incidence angles and wavelengths, for S-polarized light than for P-polarized light.

[0099] Preferably, the reflectivity of the reflector element 22 for P-polarized light, over the given range of angles of incidence and wavelength range, is greater than or equal to 10 percent, preferably greater than or equal to 15 percent, advantageously greater than or equal to 20 percent, advantageously greater than or equal to 40 percent.

[0100] Advantageously, the reflectivity of the reflector element 22 for light of polarization other than P polarization, over the range of angles of incidence and over the given range of wavelengths, is less than or equal to 10 percent, preferably less than or equal to 5 percent.

[0101] Advantageously, the range of angles of incidence extends over at least 20 degrees, preferably at least 40 degrees, advantageously at least 60 degrees.

[0102] The reflector element 22 includes, for example, a stack of dielectric layers.

[0103] The reflector element 22 is, for example, a polarizer having a specific reflectivity for P-polarized light, as described in patent application WO 96 / 19347 A.

[0104] In particular, the reflective element 22 comprises, for example, a multilayer polymer film comprising layers of a crystalline or semi-crystalline naphthalene dicarboxylic acid polyester, for example a 2,6-polyethylene naphthalate ("PEN") or a copolymer derived from ethylene glycol, naphthalene dicarboxylic acid and certain other acids such as terephthalate ("co-PEN"), with a positive optical stress coefficient, i.e. when stretched, its refractive index in the direction of stretching increases, having an average thickness not exceeding 0.5 micron; and layers of a second selected polymer, for example a polyethylene terephthalate ("PET") or a co-PEN, having an average thickness not exceeding 0.5 micron.

[0105] In another example, the reflective element 22 comprises a multilayer polymer film comprising layers of a crystalline or semi-crystalline polyester, for example PET, having an average thickness of not more than 0.5 micron; and layers of a second selected polymer, for example polyester or polystyrene, having an average thickness of not more than 0.5 micron; wherein said film has been stretched in at least one direction to at least twice the unstretched dimension of that direction.

[0106] In one example implementation, the reflector element 22 also has at least one coating providing additional optical and / or mechanical properties. The coating is, for example, thermal protection, a color-neutralizing treatment, or an anti-scratch or anti-fog coating.

[0107] The emission unit 24 is designed to emit a light beam incident on the reflector element 22. The incident beam F carries information which is, for example, as described previously.

[0108] The incident beam F, emitted by the emitting unit 24, is a beam polarized according to a specific polarization, called the main polarization.

[0109] The principal polarization is a linear polarization contained in the plane of incidence, called P polarization. The principal polarization is thus different from an S polarization, a circular polarization or an elliptical polarization.

[0110] The wavelengths of the incident beam F are in the wavelength range given for the reflector element 22, typically in the visible.

[0111] The emission unit 24 is configured so that the incident beam F arrives on the reflector element 22 with an angle of incidence 0j within the range of angles of incidence defined previously for the reflector element 22.

[0112] The operation of the head-up display device 16 according to this embodiment is similar to that of the general case, the differences in operation residing in the polarization of the beam sent by the emission unit 24, as well as in the optimized reflection of the reflector element 22 for a light of polarization P.

[0113] Thus, this specific embodiment has the advantage of being compatible with polarized solar lenses. Such lenses are typically configured to transmit only P-polarized light and reject other types of polarization. The combination of a specific polarization of the beam emitted by the emitting unit 24 and the optimized reflection of the reflecting element 22 makes it possible to optimize the reflection and therefore the visibility of the useful image through polarized solar lenses.

[0114] Second method of integrating the head-up display device 16

[0115] A second method of integrating the head-up display 16 into the vehicle 10 is shown with reference to Figures 4 and 5. This second method of integration has the same characteristics and variations as the first method of integration (illustrated in Figure 1), with the exception of the features described below. Therefore, the second method of integration is described by contrasting it with the first method, and identical features are not repeated. In particular, the features described in relation to Figures 2 and 3 also apply here.

[0116] In the second integration mode, the head-up display device 16 is not integrated into the dashboard 14 of the vehicle 10, but is formed in a part of the windscreen 12.

[0117] In particular, as illustrated in detail in Figure 5, the windscreen 12 comprises a transparent surface 12A, a screen-printed area 12B and an intermediate area 12C.

[0118] The screen-printed area 12B surrounds the transparent surface 12A.

[0119] The screen-printed area 12B is an opaque area. The screen-printed area 12B is typically made of ceramic. The screen-printed area 12B comprises a lower portion 40 (at the bottom of the windshield), two lateral portions 42 (on the sides of the windshield), and an upper portion 44 (at the top of the windshield). The lower portion 40 is typically a band extending substantially across the width of the transparent surface 12A (i.e., across the entire width of the windshield 12, at the bottom). The lower portion 40 is standard on all windshields.

[0120] The intermediate zone 12C is an area exhibiting the property or properties described previously for the panel 20 of the head-up display 16 (variable opacity depending on the activation command, optionally variable tint depending on the activation command). The description of these properties and the activation command is the same as for the first integration mode.

[0121] For example, the intermediate zone 12C corresponds to a zone of the windshield 12 on or in which a material having these properties is integrated. As explained for the first integration method, the material is preferably a switchable (active or passive) material.

[0122] The intermediate zone 12C extends from the lower part 40 of the screen-printed zone 12B. In particular, the intermediate zone 12C is a portion of the windscreen 12 which is raised from the lower part 40 of the screen-printed zone 12B.

[0123] The intermediate zone 12C forms the panel 20 of the head-up display 16. In particular, the surface of the intermediate zone 12C facing the interior of the vehicle 10 forms the usable surface 21 of the panel 20. The intermediate zone 12C is, therefore, a specific feature of this integration method, enabling the projection of useful images onto the windshield 12. The maximum height of the intermediate zone 12C is typically lower than the standards prescribed for opaque windshield bases so as not to obstruct the driver's vision 18.

[0124] Preferably, the intermediate zone 12C includes at least one raised portion 60 suitable for positioning opposite a vehicle user 10, for example, the upper body of a driver 18 in the driving position or a vehicle passenger. The raised zone 60 is thus preferably positioned opposite the driver's seat and / or the front passenger seat.

[0125] Preferably, the intermediate zone 12C comprises a band 62 projecting from the lower portion 40 of the screen-printed zone 12B and extending substantially across the width of the transparent surface 12A, except for the edges 64, which are unobstructed. In other words, the intermediate zone 12C does not extend over portions of the lower portion 40 of the screen-printed zone 12B adjacent to the pillars 15 of the vehicle 10. This ensures clear visibility of the surroundings at the level of the pillars 15 of the vehicle 10.

[0126] Preferably, the raised portion 60 is an area that is higher than the band 62 and protrudes from the band 62. The raised portion 62 allows access to a larger display area at the driver's level 18.

[0127] Alternatively, the intermediate zone 12C includes only the raised portion 60 (without the band 62).

[0128] Alternatively, the intermediate zone 12C has a different design or shape depending on the desired head-up display for vehicle 10.

[0129] As a further alternative, panel 20 is formed by another portion of the windshield 12.

[0130] The operation and advantages of the second integration method are the same as those described previously for the first integration method and its variants.

[0131] The second integration method also has the advantage of further optimizing space in the vehicle, and simplifying the design of the dashboard 14 which is not modified to integrate the panel 20. Ergonomics and visibility are also improved since the on-board information is displayed directly on the opaque portion of the windscreen 12 (therefore in the driver's field of vision and with good contrast).

[0132] A person skilled in the art will understand that the implementation methods described above can be combined with each other.

[0133] Those skilled in the art will also understand that this description is based on the specific case of motor vehicles, but that the invention is not limited to this type of vehicle. The head-up display device is therefore adaptable to all types of vehicles, including aircraft and naval vessels.

[0134] In what follows, we present optional additions or variants, applicable to the first and second mode of integration of the head-up display device.

[0135] As an optional addition or alternative, the activation command is automatically defined based on a measurement of the brightness at the level of the usable surface 21 of the panel 20, the measurement having been carried out by at least one sensor integrated into the vehicle 10. The measurement of the brightness at the level of the usable surface 21 is the measurement of the background brightness perceived through the usable surface 21. This brightness measurement will allow the opacity of the panel 20 and therefore the contrast of the display to be adjusted.

[0136] Specifically, the activation control is such that the higher the measured brightness at the usable surface 21, the more opaque the panel 20 will be, and vice versa. This allows for consideration of the contrast between the display at the usable surface 21 and its surroundings. For example, for a vehicle 10 traveling in sunny weather on a shaded road, the opacity of panel 20 will be moderate due to the shaded road. In another example, for a vehicle 10 traveling in overcast weather on a snowy road, the opacity of panel 20 will be high due to the strong reflection from the snow.

[0137] As an optional addition or alternative, the activation command is defined automatically based on a prior detection carried out by at least one sensor in the vehicle 10, the prior detection being relative to a user of the vehicle 10.

[0138] For example, prior detection includes detecting whether or not a user is wearing sunglasses. In the latter case, the activation command is configured to take into account whether or not sunglasses are being worn in order to adjust the opacity of panel 20. For example, the opacity of panel 20 is reduced if sunglasses are present.

Claims

DEMANDS 1. Head-up display device (16) adapted for integration into a vehicle (10) to display information to one or more users of a vehicle (10), the device (16) comprising: a panel (20) having a usable surface (21) at least a portion of which is adapted to be positioned facing one or more users of the vehicle (10), the panel (20) having an opacity adapted to vary between transparent and opaque according to an activation command, a reflector element (22) covering the usable surface (21) of the panel (20), the reflector element (22) being at least partially reflective, and an information emission unit (24), the emission unit (24) being adapted to emit at least one light beam in the direction of the reflector element (22) such that the reflection of the light beam on the reflector element (22) forms at least one usable image in a viewing window of a vehicle user (10).

2. Device (16) according to claim 1, wherein the panel (20) also has a tint that varies according to the activation command, preferably the tint of the panel (20) being black when the panel (20) is opaque.

3. Device (16) according to claim 1 or 2, wherein the activation command is triggered by a user of the vehicle (10).

4. Device (16) according to claim 1 or 2, wherein the activation command is triggered automatically depending on environmental conditions.

5. Device according to any one of claims 1, 2 and 4, wherein the activation command is automatically defined as a function of a measurement of the brightness at the level of the useful surface (21) of the panel (20), the measurement having been carried out by at least one sensor integrated into the vehicle (10).

6. Device according to any one of claims 1, 2, 4 and 5, wherein the activation command is automatically defined as a function of a prior detection carried out by at least one sensor in the vehicle (10), the prior detection being relative to a user of the vehicle (10).

7. Device according to claim 6, wherein the prior detection includes the detection or not of the wearing of sunglasses by a user of the vehicle (10).

8. Device (16) according to any one of claims 1 to 7, wherein the panel (20) is made of a switchable material, for example a photochromic material or an electrochromic material.

9. Device (16) according to any one of claims 1 to 8, wherein the panel (20) is formed of several portions, the variation of opacity of the panel (20) being implemented on one or more portions of the panel (20) and / or in the form of a gradient, depending on the activation command.

10. Device (16) according to any one of claims 1 to 9, wherein the device (16) is adapted to be integrated into the dashboard (14) of the vehicle (10), the panel (20) being adapted to be fixed directly to the dashboard (14) of the vehicle (10).

11. Device (16) according to any one of claims 1 to 10, wherein the vehicle (10) comprises a windscreen (12), the panel (20) being formed in a portion of the windscreen (12).

12. Device (16) according to claim 11, in which the windscreen (12) comprises a transparent surface (12A), a screen-printed area (12B) and an intermediate area (12C), the screen-printed area (12B) surrounding the transparent surface (12A), the screen-printed area (12B) comprising a lower part (40), the intermediate area (12C) extending from the lower part (40), the intermediate area (12C) forming the panel (20).

13. Device (16) according to claim 12, wherein the vehicle (10) comprises pillars (15) connected to the lateral portions (42) of the screen-printed area (12B) of the windshield (12), the intermediate area (12C) comprising a strip (62) projecting from the lower portion (40) of the screen-printed area (12B) and extending over substantially the width of the transparent surface (12A) except for the ends of the lower portion (40) of the screen-printed area (12B), which are unobstructed, so as to provide visibility of the surroundings at the level of the vehicle pillars (15).

14. Device (16) according to any one of claims 1 to 13, wherein the emitting unit (24) is adapted to emit, in the direction of the reflector element (22), a light beam polarized according to a principal polarization, called the incident beam (F|), the incident beam (F|) arriving at the reflector element (22) at an angle of incidence (Oj) and defining with the reflector element (22) a plane of incidence, the principal polarization being a polarization contained in the plane of incidence, called the P polarization, the reflector element (22) being optimized so as to have greater reflectivity over a range of angles of incidence including the angle of incidence (0i), for a light of polarization P than a non-optimized reflector element (22).

15. Vehicle (10) in which a device (16) according to any one of claims 1 to 14 is integrated.

Images