DE102022100796A1 - Lighting device for the interior of a motor vehicle - Google Patents

Abstract

Lighting device for the interior of a motor vehicle, comprising at least one light source (1) and at least one hologram (3), the lighting device being set up in such a way that part of the light (8) emanating from the at least one light source (1) is incident on the hologram ( 3) strikes and interacts with the hologram (3) so that an image (5, 5a, 5b) stored in the hologram (3) is reconstructed and is visible to a viewer of the lighting device, and wherein the lighting device in addition to the hologram ( 3) comprises a luminous surface (4) from which light (8) of white color emanates during operation of the lighting device, the reconstructed image (5) having a color different from white.

Description

The present invention relates to a lighting device for the interior of a motor vehicle according to the preamble of claim 1.

A lighting device of the type mentioned above is from WO 2016/087644 A1 known. The lighting device described therein can be provided for the interior of a motor vehicle and in particular can be integrated into a door sill of the vehicle. The lighting device comprising a light source and a hologram, the light emanating from the light source impinging on the hologram and interacting with the hologram.

Holographic lighting devices are possible, especially in vehicle interiors, especially for future autonomous vehicles. From today's perspective, autonomous vehicles will make completely new demands on the design of the vehicle interior, which will have more of a living space character than it does today. It is fitting that the lighting of switches, displays or shelves, such as a cup holder, and storage compartments, which is very functional today, is also being developed further and that lighting technology in particular must provide new accents in the vehicle interior.

Holograms as optical elements for lighting devices and/or display functions provide new, hitherto hardly used and realizable appearances that ensure the desired upgrading and redesign in the vehicle interior. In particular, 3D image holograms, which produce and show a particular depth effect and three-dimensionality despite a flat hologram surface and ideal flat integration into components for the vehicle interior, can be used to advantage here.

The sill or door entry strips represent an element which is often used as a decorative element when the door is opened. The strip is often implemented simply as a chrome cover or a part with a contrasting color, often with lettering or a logo. In addition, there are also variants with lighting, but usually designed as illuminated lettering or illuminated logo, analogous to the simple chrome or decorative panel. This means that the illuminated element, such as the lettering or the logo in particular, lights up as a surface element and is usually represented as a diffuse element.

In normal cars, the door sill or sill strip is a narrow element, while SUVs, vans or other larger vehicles, such as trucks and buses, also have wider entry surfaces.

For the interior of a vehicle, in which simple interior lights and reading lights were used in the past and today additional edges and lines on the dashboard or the door panels are ambiently illuminated by light guides and different light colors can often already be selected, for future vehicle interiors, especially for future autonomous vehicles, worked on completely new lighting concepts and emotional lighting scenarios. Holographic lighting systems can create scenarios with an impressive depth and 3D appearance as well as create completely new implementations of an interior light.

Holograms are a very well suited technology for the design of lighting devices, especially in vehicle interiors, and for personalization and individualization. Image holograms with a two-dimensional or three-dimensional impression for the viewer offer special design options.

It is known that a hologram of a designated area and size is designed to be illuminated by a monochrome light source to reconstruct a holographic image. The viewer then sees an image that has been previously specified or desired for the holographic exposure, for example a symbol, a graphic, a logo, a text or a combination of the options mentioned.

However, the hologram itself is related to the luminous flux provided by the light source and the illumination area with its proportion of the luminous surface in the total surface or its luminous objects in the holographic image, its visibility range for the holographic image or its so-called eyebox and its lighting efficiency for the reconstruction of the holographic image limited in its brightness. The hologram is partly used for decorative, ambient lighting and, depending on the size and the luminous surface or brightness, may not be sufficient for acceptable or high-quality interior lighting. Additional ambient light is therefore desirable or necessary to provide basic brightness for an interior light.

The problem underlying the present invention is the creation of a lighting device of the type mentioned, with which a greater basic brightness can be provided.

According to the invention, this is achieved by a lighting device of the type mentioned at the beginning with the characterizing features of claim 1 . The dependent claims relate to preferred embodiments of the invention.

According to claim 1 it is provided that the lighting device comprises, in addition to the hologram, a luminous surface from which light of white color emanates during operation of the lighting device, the reconstructed image having a color different from white. Sufficient basic brightness can be ensured by the lighting device due to the luminous surface, from which the light of white color emanates.

Provision can be made for the luminous surface to be arranged adjacent to the hologram, in particular with the luminous surface at least partially surrounding the hologram. As a result, backlighting is implemented which, for example, surrounds the reconstructed image that stands out from the plane of the luminous area.

Preferably, the lighting device can be set up such that the at least one light source whose light interacts with the hologram also generates the light that emanates from the luminous surface. In this way, both the image stored in the hologram and the desired basic brightness can be generated with one light source. The lighting device can thus be integrated flexibly and variably into the entire lighting device of the interior of the motor vehicle.

There is a possibility that the at least one light source generates white light. Reconstructing a hologram using a white light source with the aim of creating a white hologram image is very difficult because a hologram is always calculated and created for a specific wavelength. In order to generate a white hologram image, at least three holograms, one each for red, blue and green, would have to be created and superimposed. However, the superimposition of the three colored holograms to form a white hologram is not easy to implement, because the holograms are reconstructed at different locations and/or in different sizes, depending on the wavelength, so that an attempt would have to be made to coordinate them with one another during the calculation and design. Here, too, small deviations that lead to blurring and annoying color fringes cannot be ruled out. It is therefore intended not to generate a superimposed white hologram image, but rather a reconstructed image in a color different from white.

Provision can be made for the at least one light source to be designed as a light-emitting diode (LED) or as a semiconductor laser, with the light source in particular comprising converter means in order to generate white light. The spectrum of a white light-emitting diode runs through the entire color range from blue to red with different intensities. It therefore also includes light of the wavelength required for the reconstruction of the image stored in the hologram.

There is the possibility that the at least one hologram is designed as a diffractive holographic surface structure or as a holographic foil of a volume hologram. In particular, the holographic foil can be easily applied to suitable surfaces of the lighting device, for example glued on.

Provision can be made for the lighting device to have optical structures, with the lighting device being set up such that light generated by the at least one light source is at least partially reflected by the optical structures in such a way that it emanates from the luminous surface. The reflective optical structures can form the luminous surface and, for example, enclose the area of the hologram or adjoin the area of the hologram on one or two sides. Alternatively, the reflective optical structures can also be arranged at a distance from the luminous surface.

Alternatively or additionally, there is the possibility that the lighting device has optical structures, the lighting device being set up such that light generated by the at least one light source is at least partially scattered or refracted by the optical structures in such a way that it emanates from the luminous surface. The light-scattering or light-refracting optical structures can either form the luminous area or be arranged at a distance from the luminous area.

It can be provided that the lighting device comprises a light guide, with the at least one hologram and the optical structures being arranged on the light guide and/or in the light guide, with the lighting device being set up so that light emanating from the at least one light source enters the Light guide occurs and interacts with the hologram and the optical structures. For example, the at least one hologram can be designed as a diffractive holographic surface structure on the light guide. Alternatively it can Hologram be applied as a holographic film of a volume hologram on a surface of the light guide. This can be, for example, the exit surface of the light guide or a surface opposite the exit surface. The optical structures can also be arranged, for example, on the exit surface or on a surface of the light guide opposite the exit surface.

It is possible for the lighting device to comprise a cavity covered by a cover pane that is at least partially or partially transparent, with the at least one hologram and the optical structures being arranged on the cover pane and/or in the cavity, with the lighting device being set up such that light emanating from the at least one light source enters the cavity or is generated in the cavity and interacts with the hologram and the optical structures. The at least one hologram and the optical structures can be arranged in particular on the side of the cover pane facing the cavity.

It can be provided that the lighting device comprises more than one hologram. The images that become visible during the reconstruction of the holograms can differ from one another in terms of their content and/or have different colors from one another. Different impressions can be conveyed to a viewer in a simple manner by means of a plurality of colored hologram images in different colors.

In particular, the lighting device can be set up such that the images reconstructed from different holograms are visible from directions that differ from one another. Furthermore, there is the possibility that the lighting device is set up to be arranged on or in a door sill or on or in a door sill strip of a motor vehicle. In particular, a first viewer, for example looking at the door sill from inside the vehicle, can see a reconstructed image that has a different color and content than an image that is visible to a second viewer, for example, looking at the door sill from the outside is. Here, for example, content such as "Welcome" and "Goodbye" as well as colors such as green and red can be selected.

• 1 das Wellenlängen-Spektrum einer als Lichtquelle einer erfindungsgemäßen Beleuchtungsvorrichtung dienenden weißen Leuchtdiode;
• 2a eine schematische Darstellung einer Leuchtfläche und der Rekonstruktion eines in einem Hologramm einer ersten Ausführungsform einer erfindungsgemäßen Beleuchtungsvorrichtung gespeicherten Bildes;
• 2b eine schematische Darstellung einer Leuchtfläche und der Rekonstruktion eines in einem Hologramm einer zweiten Ausführungsform einer erfindungsgemäßen Beleuchtungsvorrichtung gespeicherten Bildes;
• 3 eine schematische Seitenansicht einer dritten Ausführungsform einer erfindungsgemäßen Beleuchtungsvorrichtung;
• 4 eine schematische Seitenansicht einer vierten Ausführungsform einer erfindungsgemäßen Beleuchtungsvorrichtung;
• 5 eine Seitenansicht eines Teils eines Innenraums eines Kraftfahrzeugs mit vier fünften Ausführungsformen einer erfindungsgemäßen Beleuchtungsvorrichtung;
• 6 eine Detailansicht des Teils des Innenraums gemäß 5;
• 7 eine Seitenansicht eines Teils eines Innenraums eines Kraftfahrzeugs mit einer sechsten Ausführungsformen einer erfindungsgemäßen Beleuchtungsvorrichtung;
• 8 eine schematische Darstellung einer Leuchtfläche und der Rekonstruktion eines in einem Hologramm einer siebten Ausführungsform einer erfindungsgemäßen Beleuchtungsvorrichtung gespeicherten Bildes;
• 9 eine schematische Seitenansicht der Beleuchtungsvorrichtung gemäß 8;
• 10 eine schematische Seitenansicht einer achten Ausführungsform einer erfindungsgemäßen Beleuchtungsvorrichtung;
• 11 eine schematische Seitenansicht einer neunten Ausführungsform einer erfindungsgemäßen Beleuchtungsvorrichtung.

The invention is explained in more detail below with reference to the attached drawings. It shows:

• 1 the wavelength spectrum of a white light-emitting diode serving as the light source of a lighting device according to the invention;
• 2a a schematic representation of a luminous surface and the reconstruction of an image stored in a hologram of a first embodiment of a lighting device according to the invention;
• 2 B a schematic representation of a luminous surface and the reconstruction of an image stored in a hologram of a second embodiment of a lighting device according to the invention;
• 3 a schematic side view of a third embodiment of a lighting device according to the invention;
• 4 a schematic side view of a fourth embodiment of a lighting device according to the invention;
• 5 a side view of part of an interior of a motor vehicle with four fifth embodiments of a lighting device according to the invention;
• 6 a detailed view of part of the interior according to 5 ;
• 7 a side view of part of an interior of a motor vehicle with a sixth embodiment of a lighting device according to the invention;
• 8th a schematic representation of a luminous surface and the reconstruction of an image stored in a hologram of a seventh embodiment of a lighting device according to the invention;
• 9 a schematic side view of the lighting device according to FIG 8th ;
• 10 a schematic side view of an eighth embodiment of a lighting device according to the invention;
• 11 a schematic side view of a ninth embodiment of a lighting device according to the invention.

Identical and functionally identical parts are provided with the same reference symbols in the figures.

The in the 2 until 11 illustrated embodiments of lighting devices according to the invention each comprise at least one light source 1. The light source 1 comprises a white light-emitting diode (LED). Alternatively, a laser diode can also be provided. The wavelength spectrum of the white light-emitting diode runs through the entire color range from blue to red with varying intensities. In 1 is a typical world len-length spectrum of a white light-emitting diode, where the intensity 2 is plotted in arbitrary units against the wavelength λ in nm.

Since the white light-emitting diode is based on a blue chip, which generates white light overall through color mixing by means of converter means, in particular by means of a phosphor conversion, for complementary light, there is a high intensity peak in the blue range at around 450 nm, which extends up to cyan at around 490 nm nm drops to a minimum. Another high intensity peak is in the green-yellow range between 530 nm and 590 nm, whereas in the red range at around 640 nm there are again rather reduced light outputs.

The illustrated embodiments of the lighting device also include at least one hologram 3 and a luminous surface 4. An image is inscribed in the hologram 3 with a specific wavelength or color, which image can be reconstructed from light of the same wavelength. When the white light from the light source 1 is applied to the hologram 3, the image with a predefined color is reconstructed. The reconstructed image 5 can then have the color blue or cyan or green or red, for example. Depending on the design of the hologram 3, this image 5 is visible in a specific angular range, which is also referred to as the eye box of the hologram 3.

2a shows an embodiment in which the hologram 3 or the image 5 reconstructed from the hologram 3 is surrounded by the luminous surface 4 . 2 B shows an embodiment in which two spaced-apart regions of the luminous surface 4 adjoin the hologram 3 or the image 5 reconstructed from the hologram 3 on different sides.

In the 3 The illustrated embodiment of the lighting device also includes a transparent pane 6, on the lower side or on the side 7 facing away from the light source 1, the hologram 3 is arranged. The pane 6 can be made of glass or plastic, for example. In this case, the hologram 3 is designed, for example, as a diffractive holographic surface structure of the pane 6 . Alternatively, the hologram 3 is designed as a holographic foil of a volume hologram, the holographic foil being applied, for example glued, in particular to the lower side 7 of the pane.

In this exemplary embodiment, the hologram 3 is a reflection hologram. It is illuminated from above through pane 6 with white light 8 from light source 1 . The white-illuminated hologram 3 now generates the image predefined in color, for example in blue, cyan, green or red, in an angular range provided by the design of the hologram 3 . The reconstructed image 5 is from above in 3 visible to the viewer through the pane 6.

In addition, the in 3 illustrated embodiment of the lighting device optical structures 9, in particular reflective optical structures, which are adjacent to the hologram 3 on the in 3 lower side 7 of the disc 6 are arranged. The optical structures 9 can surround the hologram 3, as is shown, for example, in 2a is indicated. The optical structures 9 can be designed, for example, as optical elements such as lenses or prisms or reflector optics or micro-optics or diffractive optical structures. The optical structures 9 reflect the white light from the light source 1 impinging on them and allow the area of the pane 6 surrounding the reconstructed image 5 to illuminate ambiently or diffusely in a defined pattern of the introduced optical structure. This area that lights up serves as a luminous area 4, from which white light emanates. This gives the viewer an impression as in 2a or 2 B pictured.

Optics such as lens optics or reflectors or screens can be provided between the light source 1 and the pane 3 .

The embodiment according to 4 essentially corresponds to that in 3 . Different from the embodiment according to FIG 4 is a second pane 10 which is arranged under the first pane 6 and covers the hologram 3 and the optical structures 9 .

It is definitely also possible to arrange the hologram 3 and/or the optical structures 9 on the second pane 10, in particular on the side 11 of the second pane 10 facing the first pane 6.

There is also the possibility of forming the hologram 3 as a transmission hologram or edge lithologram.

The 5 until 7 show lighting devices according to the invention, which are arranged on door sill strips 12 of a motor vehicle. For this purpose, lighting plates 13 are integrated into the door sill strips 12 and can have the hologram 3 and the optical structures 9 connected thereto. The lighting panels 13 can the discs 6, 10 according 3 and 4 are equivalent to. The associated light sources 1 are each arranged above the door sill strips 12 on the lateral door border 18 .

7 FIG. 12 shows an embodiment of the lighting device, which comprises two holograms 3, not shown, integrated into the lighting plates 13. FIG. The images 5a, 5b that become visible during the reconstruction of the holograms 3 can differ from one another in terms of their content. They can also have different colors from one another. Furthermore, they can also have different angular ranges from which the reconstructed image 5a, 5b is visible.

In particular, a reconstructed image 5a can be visible to a first observer looking at the door sill strip 12 from the outside, which has a different color and content than an image 5b that is visible to a second observer looking at the door sill strip 12 from the interior of the vehicle viewer is visible. Here, for example, content such as "Welcome" for image 5a and "Goodbye" for image 5b as well as colors such as green and red can be selected. Other colors and content are also possible.

The in the 8th until 10 Illustrated embodiments of a lighting device according to the invention each include a light guide 14, which has an entry surface 15 for the light 8 emanating from the light source 1, into which the light 8 can be coupled. The embodiments differ according to 9 and 10 by the shape of the light guide 14. The hologram 3 is in the in 9 and 10 illustrated embodiments formed as an edge lithologram and arranged on an exit surface 16 of the light guide 14, which is formed by one of the longitudinal sides of the elongated light guide 14. Because the hologram 3 is arranged on the exit surface 16 of the light guide 14, these lighting devices also include a transparent cover plate 17, which can protect the hologram 3 from damage. Alternatively, the hologram could also be arranged on the side 21 of the light guide opposite the exit surface 16 . In this case, the transparent cover plate 17 could be dispensed with.

The in the 8th until 10 The illustrated embodiments of an illumination device according to the invention include optical structures 19, in particular scattering optical structures, which can be arranged next to the hologram 3, in particular the hologram 3 can surround (see 8th ). Like the optical structures 9, the optical structures 19 can be designed, for example, as optical elements such as lenses or prisms or micro-optics or diffractive optical structures. The light 8 entering the light guide 14 through the entry surface 15 passes through the light guide 14. A proportion of the white light hits the hologram 3 and reconstructs a colored image 5, while the remaining light 8 passes through the light guide 14 unhindered and is refracted at the optical structures 19 or is scattered and causes them to light up. The area in which the optical structures 19 are arranged thus serves as a luminous surface 4 from which white light emanates.

Alternatively, the light guide 14 can also be made of a special light guide material which, thanks to integrated nanoparticles, offers planar illumination when the light guide 14 is illuminated from an edge, but otherwise appears as a transparent pane.

The in the 8th until 10 The illustrated embodiments of a lighting device according to the invention comprise a transparent area formed by the transparent cover plate 17 and an opaque, non-transparent area 20, behind which the light source 1 is arranged in a concealed manner. Alternatively, the opaque area 20 can be embodied as a transparent component and in particular can be part of the transparent cover pane 17 . In this case, an internal screen (not shown) can cover the light source 1.

In the 11 illustrated embodiment of a lighting device according to the invention comprises a housing 22 with a transparent cover plate 23, wherein a cavity 24 is formed in the housing 22, in which the light source 1 is arranged. The hologram 3 and light-scattering and/or light-refracting optical structures 19 are arranged on the side of the cover plate 23 facing the cavity. The hologram 3 is designed in particular as a transmission hologram.

The arrangement of the light source and the arrangement of the hologram 3 and the optical structures 19 are selected in such a way that the light emanating from the light source 1 strikes the hologram 3 directly. Alternatively, there is the possibility that optical means such as at least one lens and/or at least one reflector are arranged between the light source 1 and the hologram 3 or the optical structures 19, in particular in order to illuminate the hologram 3 with collimated light.

The image 5 reconstructed in color by the white light 8 is visible from the outside through the cover pane 23 . The white light 8 emanating from the optical structures 19 passes through the cover pane 23 and forms a luminous area 4 on the cover pane 23 adjacent to the image 5.

It is quite possible that the hologram and/or the optical structures 19 are not arranged on the cover plate 23 but on a part of the housing 22 opposite the cover plate 23 . In this case, the hologram 3 can be designed as a reflection hologram.

Reference List

1

light source

2

Intensity of the light emitted by a light-emitting diode

3

hologram

4

luminous surface

5, 5a, 5b

reconstructed image

6

first slice

7

side of the pane facing away from the light source

8th

light emanating from the light source

9, 19

optical structures

10

second disc

11

side of the second pane facing the first pane

12

Door sill of a motor vehicle

13

lighting panel

14

light guide

15

entry surface of the light guide

16

Exit surface of the light guide

17

transparent cover plate

18

lateral door limitation of a motor vehicle

20

opaque area

21

side of the light guide opposite the exit surface

22

Housing

23

transparent cover plate of the housing

24

cavity in the housing

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 2016/087644 A1 [0002]

Claims (15)

Lighting device for the interior of a motor vehicle, comprising at least one light source (1) and at least one hologram (3), the lighting device being set up in such a way that part of the light (8) emanating from the at least one light source (1) is incident on the hologram ( 3) strikes and interacts with the hologram (3), so that an image (5, 5a, 5b) stored in the hologram (3) is reconstructed and is visible to an observer of the lighting device, characterized in that the lighting device in addition to that Hologram (3) comprises a luminous surface (4) from which light (8) of white color emanates during operation of the lighting device, the reconstructed image (5, 5a, 5b) having a color different from white. lighting device claim 1 , characterized in that the luminous surface (4) is arranged adjacent to the hologram (3), in particular wherein the luminous surface (4) surrounds the hologram (3) at least partially. Lighting device according to one of Claims 1 or 2 , characterized in that the lighting device is set up such that the at least one light source (1) whose light interacts with the hologram (3) also generates the light (8) which emanates from the luminous surface (4). Lighting device according to one of Claims 1 until 3 , characterized in that the at least one light source (1) generates white light. Lighting device according to one of Claims 1 until 4 , characterized in that the at least one light source (1) is designed as a light-emitting diode or as a semiconductor laser, the light source (1) in particular comprising converter means to generate white light (8). Lighting device according to one of Claims 1 until 5 , characterized in that the at least one hologram (3) is designed as a diffractive holographic surface structure or as a holographic film of a volume hologram. Lighting device according to one of Claims 1 until 6 , characterized in that the lighting device has optical structures (9), the lighting device being set up such that the at least one light source (1) generated light (8) is at least partially reflected by the optical structures (9) in such a way that it from the luminous surface (4). Lighting device according to one of Claims 1 until 7 , characterized in that the lighting device has optical structures (19), the lighting device being set up such that light (8) generated by the at least one light source (1) is at least partially scattered or refracted by the optical structures (19) in such a way that that it emanates from the luminous surface (4). Lighting device according to one of Claims 1 until 8th , characterized in that the lighting device comprises a light guide (14), the at least one hologram (3) and the optical structures (9, 19) being arranged on the light guide (14) and/or in the light guide (14), wherein the lighting device is set up so that the light (8) emanating from the at least one light source (1) enters the light guide (14) and interacts with the hologram (3) and the optical structures (9, 19). Lighting device according to one of Claims 1 until 9 , characterized in that the lighting device comprises a cavity (24) covered by a cover pane (23) that is at least partially or partially transparent, the at least one hologram (3) and the optical structures (9, 19) on the cover pane (23) and / or are arranged in the cavity (24), the lighting device being set up such that light (8) emanating from the at least one light source (1) enters the cavity (24) or is generated in the cavity (24) and with the hologram (3) and the optical structures (9, 19) interacts. Lighting device according to one of Claims 1 until 10 , characterized in that the lighting device comprises more than one hologram (3). lighting device claim 11 , characterized in that the images (5, 5a, 5b) that become visible during the reconstruction of the holograms (3) differ from one another in terms of their content. Lighting device according to one of Claims 11 or 12 , characterized in that the images (5, 5a, 5b) that become visible during the reconstruction of the holograms (3) have different colors from one another. Lighting device according to one of Claims 11 until 13 , characterized in that the lighting device is set up such that the images (5, 5a, 5b) reconstructed from different holograms (3) are visible from directions which differ from one another. Lighting device according to one of Claims 1 until 14 , characterized in that the lighting device is set up to be arranged on or in a door sill or on or in a door sill strip (12) of a motor vehicle.

Images