Display device for a vehicle

Abstract

TITLE: Display device for a vehicle Display device comprising a holographic film (2) and a projector (4) directed towards the holographic film (2) on a window (8) of the vehicle. A black printed layer (6) is provided on the side of the holographic film opposite that of the projector (4) and it overlaps the holographic film (2) by an overlapping area (10) illuminated at least in part by the projector (4). Figure 1

Description

Title of the invention: Display device for a vehicle FIELD OF THE INVENTION

[0001] The present invention relates to a display device for a vehicle comprising a holographic film and a projector. STATE OF THE ART

[0002] Optical vehicle display systems are already known that use mirrors, screens and other very bulky optical components in the dashboard. A space-saving possibility for providing optical functions are holographic films or holographic optical elements.

[0003] DISCLOSURE AND ADVANTAGES OF THE INVENTION

[0004] The present invention relates to a display device for a vehicle comprising a holographic film and a projector installed to emit light at least partially towards the holographic film provided on a window of the vehicle, a black printed layer being provided on the side of the holographic film opposite that of the projector, it overlaps the holographic film by an overlapping zone illuminated at least in part by the projector.

[0005] In other words, according to the invention, there is a black printed layer on the side of a holographic film opposite that of the optical projector. The holograms are thus installed in front of the black printing (depending on the direction of space), which results in a strong contrast thus allowing good visibility of the projected images such as, for example, the speed display. The information or images can be brought much closer to the normal field of vision of the vehicle occupants, in particular the driver, than the dashboard displays.

[0006] In more detail, the display device comprises a holographic film and a projector installed so that its light is emitted at least partly towards the holographic film. The holographic film is installed on a window of the vehicle or in an intermediate layer of a composite window and a black printed layer is provided on the side of the holographic film, opposite that of the projector and, if necessary, it is also integrated, if necessary, in the composite window. The black printed layer partially overlaps the holographic film in a so-called overlapping area; the overlapping area is illuminated at least partly by the projector.

[0007] Holographic films are transparent, thin, photosensitive polymer (photopolymer) films into which an optical function based on the modulation of the refractive index by an illumination process. Depending on the illumination, holographic films process light to direct and diffract it with light rays analogous to real rays from optically effecting bodies, such as mirrors or lenses.

[0008] Holographic films may have a single- or multi-layer structure and at least one holographic layer (for example, having a thickness of the order of 15 μm to 100 μm) which receives a holographic structure or a hologram. For the holographic layer, a photopolymer is used, i.e. a material whose properties vary when illuminated in the uncured state with light of a certain frequency range (generally UV light or visible light); this results in crosslinking of the polymers, which blocks the variations by curing, thus generating optical elements such as holographic structures (diffraction grating). As a further layer, there is, for example, a support layer having a thickness of the order of 50 μm to 300 μm. The material of the support layer is, for example, a polyamide and / or a polycarbonate and / or a cycloolefin copolymer.The holographic layer, and if applicable, at least one support layer are transparent regardless of the optical properties of the holographic structures.

[0009] A hologram is in particular a holographic optical element, i.e. having a holographic structure in a photopolymer layer which functions like a usual optical element such as a lens, a diffraction surface or a mirror. Such a holographic optical element is formed, for example, by a holographic grating, i.e. a diffraction grating having a low lattice constant; the diffraction grating is, for example, formed by an appropriate variation of the diffraction index in the photopolymer layer. This structure of the photopolymer layer is hereinafter referred to as a holographic structure.

[0010] The term "light-proof black color layer" refers to a black print that is thus completely light-proof or partially transparent. In the case of a partially transparent embodiment, the black print darkens the image that appears. The transparency of the black print may be comprised for light in the range of wavelengths of light visible to the human eye, for example, between 0% and 90%, preferably in a range of 0% to 50% and more preferably in a range of between 0% and 25% and exceptionally preferably in a range of between 0% and 10%.

[0011] The term "projector" generally refers to an optical projection unit or projection system for projecting images in the form of light in a specific direction, i.e. in an angular range or a projection area in this direction. The light source of the projector is preferably LED diodes because they are relatively small.

[0012] According to another characteristic, the holographic film has a transparency zone located in the window and which is not overlapped by the black printed layer. The overlapping zone is preferably located between the edge of the window and the transparency zone or transparent zone. This makes it possible to enlarge the surface used for holographic projections, the transparent zone being able to reach the normal field of vision of a vehicle occupant looking at the roadway because the holographic film is transparent in itself. The holographically projected information / images are also superimposed on the field of vision of a vehicle occupant, as in the case of the HUD (i.e. head-up display) display system.

[0013] Preferably, the overlapping area has a first diffraction structure and the transparent area has a second diffraction area; the first diffraction area is designed to diffract the light from the projector towards a first field of view and the second diffraction area is designed to diffract the light from the projector towards a second field of view, the first field of view preferably being different from the second field of view. Images intended for different vehicle occupants can thus be diffracted or deflected into corresponding fields of view.

[0014] Preferably, the second field of view is included in the first field of view; the first field of view preferably includes a driver's eye range and a passenger's eye range, and the second field of view includes the driver's eye range. The terms "driver's eye range" and "passenger's eye range" herein refer to the areas inside the vehicle in which the driver's eyes or the passenger's eyes are usually located. These areas may be large enough to cover the eye range of people of different sizes and seating positions. The first field of view is used to display information relating to both the driver and passengers, such as weather information, the time, a song displayed by the vehicle's music system, or the like.The second field of view is used to display information relevant only to the driver such as speed, warning information or similar information. The passenger's eye range is preferably not encompassed in the second field of view.

[0015] Preferably, the holographic film comprises at least one diffraction structure which diffracts the light from the projector having a wavelength or color corresponding to the diffraction structure, in the direction of a predefined field of vision. in the vehicle interior, preferably with a diffraction structure for red light or a diffraction structure for green light and a diffraction structure for blue light. Since the diffraction structures are specific to a light color, i.e. for spectral colors, a high contrast is achieved. The use of red, green, blue makes it possible to represent colors visible to the human eye. Red light is in a wavelength range between 630 and 700 nm (nanometers); green light is in a wavelength range between 490 and 560 nm and blue light in a wavelength range between 450 and 490 nm.

[0016] Preferably, the holographic film has several diffraction structures designed to diffract light towards the same field of vision or towards different fields of vision in the passenger compartment of the vehicle. The diffraction structures are used to diffract images in different directions, in particular determined directions or in different colors of a determined direction and in particular the same direction.

[0017] Preferably, the holographic film and / or the black printed layer are integrated into the window; the window is preferably a composite window and the holographic film and / or the black printed layer are integrated into the composite layer forming the composite window. This simplifies assembly because the holographic film and the black printed layer are thus pre-assembled in the window and thus installed in the vehicle via the window.

[0018] Preferably, the holographic film and the black printed layer may also be provided in a region outside the window and which reaches the window. The areas located directly next to the window may serve as a projection surface. Preferably, the projector is designed to illuminate an area which at least partially includes the holographic film inside and outside the window. This embodiment makes it possible to have a relatively large display surface with only a holographic film inside the window.

[0019] Preferably, the projector is fixed to or on the dashboard of the vehicle, or to the ceiling (roof) of the vehicle and / or on a column bordering the window. To simplify the presentation, reference will always be made here to a projector. However, it is possible to have several projectors which illuminate the same holographic film or different holographic films. The expression "a projector" is to be taken as a synonym for "at least one projector". In principle, several projectors can also be considered as parts of the same projector or a system of projectors.

[0020] Preferably, the window is a windshield or in particular a front side window (i.e. a window of a front window) of the vehicle. These windows are located, characteristically, in the field of vision of the vehicle's occupants. But one can also consider the rear window of the vehicle.

[0021] The black printed layer is preferably provided at the edge of the vehicle window and / or outside the driver's field of vision so as not to disturb the normal field of vision or to disturb it only very slightly. The driver's field of vision is located in a vertical strip approximately 30 cm wide, precisely in the middle of the steering wheel. The top and bottom of the driver's field of vision are delimited by the area of ​​action of the windscreen wiper.

[0022] Preferably, the black printed layer has a vertical extension relative to the edge of the window which is less than 10 cm, and more preferably, an extension of less than 5 cm. Vision through the window is thus relatively little disturbed. A possible minimum extension is, for example, 2 cm or 1 cm. Brief description of the drawings

[0023] The present invention will be described below in more detail with the aid of a production method shown in the accompanying drawings in which:

[0024] [Fig-1] sectional view of the installation of a display device in a vehicle,

[0025] [Fig.2] sectional view of a preferred embodiment of a display device according to the invention in a vehicle,

[0026] [Fig.3] perspective view of a possible embodiment of the invention.

[0027] DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0028] [Fig.l] is a sectional side view of the installation of a display device in a vehicle. The display device comprises a holographic film 2, a projector 4 and a black printing layer 6.

[0029] The holographic film 2 is installed on the windshield 8 (for example between the layers of a composite windshield). The holographic film 2 is provided at the lower edge of the windshield (windshield base). The holographic film 2 has a holographic structure (for example an optical network in the form of variations in the refractive index) i.e. a hologram.

[0030] The projector 4 is installed under the dashboard 20 and is oriented so that the light 14 emitted by the projector 4 falls at least partly on the holographic film 2; in other words, the projector illuminates the holographic film. As shown by way of example, the projector 4 can be installed as is or with a cavity 22 in the dashboard 20. The holographic structure of the holographic film 2 diffracts the light from the projector or reflects it and returns it as diffracted light 16 towards the field of vision 24. The holographic film, in particular, the holographic structure (for example the intervals of the lines of the structure), the projector (in particular the wavelength of the emitted light) and the relative positioning are designed and defined with respect to each other so that the light emitted in the direction of the field of vision 24 is diffracted.

[0031] The black printing layer 6 is provided on one side of the holographic film 2 opposite the projector 4; viewed from the projector, the black printed layer 6 is behind the holographic film 2. The black printed layer 6 overlaps the holographic film 2 in an overlapping area 10 of the holographic film. The overlapping area may cover the entire black printing layer 6.

[0032] The installation is carried out in such a way that the light 14 emitted by the projector reaches at least part of the overlapping zone 10.

[0033] The black printing layer may also be located between the layers of the composite windshield 8, for example, directly next to the holographic film 2 and if possible, so that the black printed layer is applied to the holographic film 2, which facilitates installation on the windshield.

[0034] The black printed layer 6 extends only to the edge of the windshield 8 and in particular has an extension such that it does not extend into the normal field of vision of the occupant of the vehicle who is looking at the roadway; the black printed layer is, for example, only in a region in which the occupant of the vehicle could see the hood of the vehicle.

[0035] [Fig. 2] is a side sectional view of the installation of a display device according to the invention in a vehicle corresponding to one embodiment. The installation corresponds largely to that of [Fig. 1] so that for the common characteristics, reference will be made to the description of [Fig. 1], the following description being limited to the differences.

[0036] Unlike [Fig.l], the black printed layer 6 does not overlap the entire holographic film 2, but the holographic film 2 has a transparent area 12 located next to the overlapping area 10; more precisely, it is located towards the middle of the windshield 8. The overlapping area is thus between the edge of the windshield and the transparent area. Unlike the overlapping area 10, the transparent area 12 can reach the field of vision of the vehicle occupant because the holographic film 2 is transparent in itself.

[0037] The projector 4 is installed so that the light it emits reaches the overlapping zone 10 and also the transparent zone 12.

[0038] In the transparent area 12 as well as in the overlapping area 10 (see [Fig.l]) the holographic film 2 has a (second) holographic structure which diffracts the light from the projector towards the vehicle interior. The (second) holographic structure of the transparent area 12 is designed so that the diffracted light 32 arrives towards the field of vision 28. The (first) holographic structure in the overlapping area 10 is, for example, designed so that its diffracted light 30 arrives in the direction of the first field of vision 26.

[0039] The second field of vision 28 is included, for example, in the first field of vision 26 according to the figure. In this case, there is also, in part, an overlap of the fields of vision or it is also possible to envisage an embodiment such that the fields of vision are disjoint. The first field of vision 26 covers, for example, the eye area of ​​the driver 34; here it is possible, for example, to embed information relating mainly to the driver such as the traffic situation or the condition of the road, warnings or information of this type. The second field of vision 28 covers, for example, both the eye area of ​​the driver and also that of the passenger 36 (it is possible, for example, to embed images of interest to the passengers).The eye zones here are the areas relating to the interior of the vehicle, i.e. the passenger compartment in which the eyes of the respective passengers are located assuming a characteristic seating position; the eye zones are set so as to be large enough so that passengers of different sizes and sitting in different positions are concerned.

[0040] It is also possible to provide several holographic structures in the overlapping area and / or in the transparent area and which diffract the light in different fields of vision; this can also depend on a color spectrum.

[0041] Alternatively or in addition to installing the holographic film 2 and the black printed layer 6 in the surface of the windshield, it is also possible to install it on the outside of the windshield next to the edge of the windshield. This is explained in [Fig. 3],

[0042] [Fig. 3] shows in perspective a possible embodiment of the invention. This figure shows in particular different possibilities of installations of holographic films, black printed layers and projectors. Independently of this, reference will be made to the description of figures 1 and 2.

[0043] The embodiment presented comprises several holographic films 2a, 2b, 2c, 2d which can be respectively independent. A first holographic film 2a provided in the windshield 8 thus has an overlapping zone 10a in which the holographic film is overlapped by a black printed layer (this is not detailed); seen in the direction of view according to the figure, the black printed layer is behind the holographic film; a transparent zone 12a is provided, i.e. a black printed layer. It corresponds to the installation of [Fig. 2]. Unlike [Fig. 2], the holographic film 2a is not illuminated by the projector housed in the dashboard, but by two projectors 4a installed in the ceiling of the passenger compartment. Generally, it is possible to have several projectors adapted to the extension of the holographic film to have regular lighting.

[0044] A second holographic film 2b is further provided on the dashboard 22, directly in junction with the windshield 8 and thus directly adjacent to the first holographic film 2a. It is also possible to have a black printed layer (seen in the direction of view according to the figure, it is behind the holographic film; this detail is not shown). With an appropriate color of the part of the dashboard in which the second holographic film 2b is located, this layer can be omitted. The second holographic film 2b is also illuminated by the projectors 4a installed in the roof. The first holographic film 2a and the second holographic film 2b can together constitute a common projection surface.

[0045] In addition, the side windows 9 of the vehicle have a third holographic film 2c (left-hand side windows) and a fourth holographic film 2d is also provided. These films are illuminated by projectors 4b fitted to the A-pillar of the vehicle body. The projectors can also be installed in the roof or on the sides of the seats. The latter solution is advantageous because it automatically compensates for the movement of the seat. The third and fourth holographic films 2c, 2d can have, next to the overlapping area, optionally, a transparent area; this situation is analogous to that of [Fig. 2], i.e. the first holographic film 2a; this variant is not shown. Similarly, the side doors can have holographic films directly under the window and thus form a common projection surface with the third and fourth holographic films.

[0046] It should be noted that holographic films constitute projection surfaces for any information, images, videos and the like. In particular, they can also be used to present images from an exterior camera of the vehicle.

[0047] It should further be emphasized that more particularly the invention relates to a holographic film 2; 2a and / or the black printed layer 6 integrated into the glass, the glass preferably being a composite glass and the holographic film and / or the black printed layer being integrated into the combination of the composite glass.

[0048] The holographic film 2b and optionally also the black printed layer are advantageously in a region outside the window 8 and which reaches as far as the window.

[0049] Furthermore, the projector 4a is provided to illuminate an area which at least partly comprises the holographic film 2a, 2b inside and outside the window.

[0050] According to another characteristic, the projector 4; 4a, 4b is on or under the dashboard of the vehicle, on the roof of the vehicle or on a column of the bodywork delimiting the window 8, 9; the window is the windshield 8 or a side window 9 of the vehicle; the black printed layer 6 has an advantageous extension measured perpendicular to the edge of the window 8, 9, less than 10 cm, preferably less than 5 cm; the printed layer in black 6 is outside the driver's field of vision.

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[0068] NOMENCLATURE OF MAIN ELEMENTS 2 Holographic film 4 Projector 6 Black printed layer 8 Windshield 10 Overlap area 12 Transparent area 14 Light emitted by a projector 16 Diffracted light 20 Instrument panel 22 Instrument panel cavity 24 Field of vision 26 First field of vision 28 Second field of vision 30 Diffracted light 32 Diffracted light 34 Driver 36 Passenger

Claims

Claims

1. Display device for a vehicle comprising: - a holographic film (2; 2a, 2b, 2c, 2d); and - a projector (4; 4a, 4b) installed to emit light at least partially towards the holographic film (2; 2a, 2b, 2c, 2d); - the holographic film (2; 2a, 2b, 2c, 2d) on a window (8, 9) of the vehicle; - a layer (6) printed in black on the side of the holographic film opposite that of the projector (4; 4a, 4b) and overlapping the holographic film (2; 2a, 2b, 2c, 2d) by an overlapping zone (10, 10a), - the overlapping zone (10, 10a) being illuminated at least in part by the projector (4; 4a, 4b), and - the holographic film (2; 2a, 2b, 2c, 2d) has a transparent zone located in the glass (8), this zone not being overlapped by the layer printed in black (6), - the overlapping zone being located between the edge of the glass and the transparency zone.

2. A display device according to claim 1, wherein the overlapping area (10, 10a) has a first diffraction structure and the transparent area (12; 12a) has a second diffraction structure, - the first diffraction structure being adapted to diffract the light from the projector towards a first field of view (26) and the second diffraction structure being adapted to diffract the light from the projector towards a second field of view (26), - the first field of view being different from the second field of view.

3. A display device according to claim 2, wherein the second field of vision (28) is included in the first field of vision (26); and - preferably, the first field of vision corresponding to the driver's eye range and the passenger's eye range and the second field of vision comprising the driver's eye range.

4. Display device according to one of the preceding claims, wherein the holographic film (2; 2a, 2b, 2c, 2d) has at least one structure of diffraction which diffracts the light from the projector (4; 4a, 4b) into a light color corresponding to the diffraction structure towards a predetermined field of vision (24, 26, 28) in the vehicle interior; - the diffraction structure preferably being a red light diffraction structure, a green light diffraction structure and a blue light diffraction structure.

5. A display device according to one of the preceding claims, wherein the holographic film (2; 2a, 2b, 2c, 2d) comprises a plurality of diffraction structures installed to diffract light towards the same field of view (24, 26, 28) or towards different fields of view (24, 26, 28) in the vehicle interior.

6. Display device according to one of the preceding claims, wherein the holographic film (2; 2a) and / or the black printed layer (6) are integrated into the glass, - the glass preferably being a composite glass and the holographic film and / or the black printed layer being integrated into the combination of the composite glass.

7. Display device according to one of the preceding claims, in which the holographic film (2b) and optionally also the black printed layer are in a region outside the glass (8) and which reaches up to the glass.

8. A display device according to claim 7, wherein the projector (4a) is further provided to illuminate an area which at least partly comprises the holographic film (2a, 2b) inside and outside the glass (8).

9. Display device according to one of the preceding claims, in which the projector (4; 4a, 4b) is on or under the dashboard of the vehicle, on the roof of the vehicle or on a column of the bodywork delimiting the window (8, 9).

10. Display device according to one of the preceding claims, in which the window is the windshield (8) or a side window (9) of the vehicle.

11. Display device according to one of the preceding claims, in which the black printed layer (6) has an extension measured perpendicular to the edge of the glass (8, 9), less than 10 cm, preferably less than 5 cm.

12. Display device according to one of the preceding claims, in which the black printed layer (6) is outside the driver's field of vision.

Images