HOLOGRAPHIC ENTRANCE LIGHT IN A DOOR FRAME

Description

[0001] The invention relates to a door frame for a vehicle, comprising a holographic entry strip in a lower door frame section and a suitable lighting arrangement in a side door frame section. Background and state of the art:

[0002] Vehicles, especially cars, often feature a so-called sill plate in the lower part of the door frame at the entrance. This sill plate can be made of plastic and / or metal, for example. On the one hand, the sill plate can serve as a more robust zone in the entry area, protecting it from damage and heavy soiling, such as that caused by getting in and out of the vehicle and by the elements when the door is open. Frequently, especially in premium vehicles, the sill plate is intended to suggest a high-quality feel to the person entering, by using premium-looking materials and, for example, displaying the vehicle or manufacturer's logo. This aesthetic function could be further enhanced by using holograms in the sill plate area.

[0003] The entry area of ​​a vehicle is often slightly raised for safety and weather protection. However, this elevation can pose a dangerous tripping hazard when getting in and out, which can be particularly problematic for elderly people or those with impaired vision, as it requires a certain degree of mobility and is often outside their field of vision. Using holograms in the area of ​​the door sill offers a solution to this problem, as the hologram can project an image outside, especially above, the sill, and the field of vision can be influenced by the hologram's diffraction. This can significantly improve the visibility of the door sill and minimize the risk of accidents.A problem with using holograms that are intended to have a certain optical quality and solve the problems described above is the limited installation space available in the door sill area. Firstly, the lower section of the door frame must be sufficiently robust to ensure crash safety, and secondly, the door should fit flush with the frame in this area. Therefore, there are limitations to the potential illumination of a hologram in the door sill, as lighting integrated into the sill would require too much space, and the electrical connection options in this area are also limited. There is no space in this area to accommodate, for example, an LED with a lens while maintaining the necessary distance from the holographic structure in the door sill for proper illumination.It should also be possible to retrofit holographic door sills to vehicles that have already been designed, which also entails strict boundary conditions.

[0004] US 2020 / 0166195 A1 describes a method for displaying information in a vehicle. This involves illuminating an optical grating, e.g., a holographic grating, with a light source. Purpose of the invention:

[0005] It is an object of the invention to provide a door frame without the disadvantages of the prior art. In particular, it is an object of the invention to provide a door frame that increases safety when entering and exiting the vehicle as well as the aesthetic appearance of the vehicle, without impairing crash safety and without increasing the costs and effort involved in manufacturing. Summary of the invention:

[0006] The problem is solved by the features of the independent claim. Preferred embodiments of the invention are described in the dependent claims.

[0007] The invention relates to a door frame for a vehicle, comprising a holographic entry strip in a lower door frame section, wherein the holographic entry strip includes a planar element with a thickness perpendicular to its planar extent of a maximum of 3 mm, which has at least one planar, reflective holographic structure configured to generate a holographic illumination function in a viewing area. "Planar" preferably means that the extent in the directions lying in a two-dimensional surface is significantly greater than in a direction perpendicular to this surface.

[0008] The surface area of ​​the holographic entry strip can, for example, be between 5 cm and 30 cm in the longitudinal direction, preferably between 10 cm and 25 cm. In the transverse direction, the area can be between 1 cm and 7 cm, preferably between 2 cm and 5 cm. An exemplary area could be 20 cm in the longitudinal direction and 5 cm in the transverse direction.

[0009] The holographic structure is preferably planar and lies in a plane with the two-dimensional surface of the holographic entry strip or parallel to it.

[0010] The area covered by the holographic structure can be within the area of ​​the door sill and is preferably somewhat smaller. Preferably, the holographic structure covers at least 20% of the area of ​​the door sill, more preferably at least 30%, even more preferably at least 40%, and most preferably at least 50%. The structure can cover up to the entire area of ​​the door sill. An exemplary extent can be 20 cm in the longitudinal direction and 5 cm in the transverse direction. Another exemplary extent of the structure can be 10 cm in the longitudinal direction and 2.2 cm in the transverse direction.

[0011] The holographic entry strip can be transparent to visible light, and in particular can comprise a transparent body.

[0012] The holographic structure can be arranged below the upper outer surface of the door sill, whereby the door sill should be transparent so that the holographic structure can be reached by illumination light and can also reflect this light back out of the door sill.

[0013] The holographic structure can be located directly on or at the upper outer surface of the door sill, in which case the door sill does not have to be transparent to visible light.

[0014] The sill plate can include a polymer body. This can be transparent or opaque to visible light.

[0015] The reflexive holographic structure is specifically designed to generate a holographic luminescence function when illuminated.

[0016] A reflective holographic structure preferably reflects the incident light, so that the illumination source on the viewer's side can be the source of the luminescence generated by the holographic structure. Advantageously, a reflective holographic structure can also generate the holographic luminescence (only) at the desired color under white light illumination, because preferably only certain wavelength ranges satisfy the Bragg condition of the reflective holographic structure.

[0017] The terms "visual area" and "field of vision" are preferably synonymous.

[0018] The reflective holographic structure is designed to generate a holographic luminescence function in a viewing area preferably means that the structure diffracts the illumination light in such a way that a generated image is recognizable in this viewing area.

[0019] Preferably, the viewing area is a definable volume located several centimeters (cm), preferably several decimeters (dm), and sometimes several meters away from the entry sill.

[0020] Such a door frame can easily enhance the aesthetic appearance of a vehicle and improve safety when getting in and out. It also takes up very little installation space.

[0021] In a preferred embodiment of the invention, the holographic structure comprises a volume hologram, which is preferably in the form of a hologram stack or a multiplexed hologram. A volume hologram preferably has a thickness between 5 µm and 200 µm.

[0022] Preferably, more than one holographic structure is included, e.g., one for a green spectral range, one for a blue spectral range, and one for a red spectral range, to produce a white-appearing image as a holographic luminescent function.

[0023] In a hologram stack, the holographic structures are arranged on top of each other, in particular stacked on top of each other.

[0024] Preferably, the holographic illumination function has a single color, whereby "color" in this context preferably refers not necessarily to the spectral sense, but rather to human color perception. For example, in this sense, not only red or blue, but also white is considered a single color. This may be preferred for aesthetic reasons and to fulfill a warning function.

[0025] In an alternative embodiment, the holographic structures are contained within a single holographic structure, particularly in a so-called holographic film, in which they were exposed together. Such a holographic structure is preferably also referred to as a multiplex hologram.

[0026] In a further preferred embodiment of the invention, the holographic structure comprises an embossed hologram.

[0027] Embossed holograms are preferably phase holograms. Preferably, the embossed hologram has depressions that create a phase difference in the reflected light. These are, for example, pressed into the material with a die, but can also be created by different exposure of suitable material. A phase hologram can preferably also exhibit a local modulation of the refractive index, which is produced, for example, in silver halide films.

[0028] Preferably, an embossed hologram is a reflective relief pattern; in particular, it can be a metallized diffracted relief structure.

[0029] The embossed hologram can be a particularly "broadband" hologram, which in some applications, especially under daylight and / or ambient light illumination, can be advantageous because the available light intensity can be better utilized even in low light conditions. In these cases, a compromise is preferably made between efficiency and optical quality, or a suitable image motif is used.

[0030] In a further preferred embodiment of the invention, the embossed hologram is comprised in an element which is configured to predominantly absorb a portion of the visible spectrum that is not intended to contribute to the generation of the holographic light function.

[0031] For example, it could be a colored cover (e.g., red) for an embossed hologram, which is transparent to that color, e.g., red, but essentially or partially absorbs visible spectra of other colors. In this way, the cover acts as a filter for the illumination light, which may contain other color ranges in its spectrum, so that the luminous effect produced under the illumination essentially only exhibits the color of the cover. This is a particularly simple and cost-effective solution.

[0032] In a further preferred embodiment of the invention, the generation of a holographic lighting function comprises the display of a virtual, in-plane and / or real image, in particular a real image at a height between 0.5 cm and 5 cm above the holographic entry strip.

[0033] This height can create a good warning function when getting in and out and ensures an improved aesthetic impression.

[0034] The image may include, in particular, a symbol or lettering, which appears especially three-dimensional and preferably seems to float above the entry strip.

[0035] In a further preferred embodiment of the invention, the holographic structure, which is preferably an embossed hologram, which is particularly included in an element according to the preceding description, is configured for generating the holographic luminescence function when illuminated by daylight and / or ambient light, particularly in a range of 420 nm to 700 nm, preferably 620 nm to 700 nm.

[0036] Daylight is light produced by the sun during the day, e.g. at midday, for example in summer or winter.

[0037] Ambient light can be generated additionally or exclusively by artificial light sources, e.g., standard interior lighting in a car.

[0038] As previously described, the holographic structure must be efficient across a broad spectral range, for which the embossed hologram is particularly well-suited. Broadband sunlight would be strongly filtered by a volume hologram designed, for example, for 650 nm + / - 5 nm. If the hologram is a volume hologram, it would preferably be designed only for this 650 nm + / - 5 nm range and would no longer diffract efficiently at, for example, 620 nm.

[0039] An embossed hologram (preferably also called a relief hologram) would also diffract efficiently at 620 nm, preferably at a different angle. Combined with a cover as described above, which would be made of plastic and applied to the top of the relief hologram (also known as an embossed hologram), the embossed hologram would then always be red (with a red cover).

[0040] Such a door frame does not require a separate lighting arrangement for the entry strip.

[0041] According to the invention, the door frame has at least one lighting arrangement arranged in at least one lateral door frame section, which is configured to illuminate the holographic entry strip, comprising at least one light source, wherein the holographic structure is configured to generate the holographic lighting function when illuminated by the lighting arrangement.

[0042] The lighting arrangement is located above and to the side of the holographic entry strip, so that illumination occurs at an oblique angle. Preferably, the lighting arrangement is configured to illuminate the holographic entry strip; this means, in particular, that the orientation, intensity, direction of radiation, and / or angular spectrum of the illumination light is such that the holographic entry light is illuminated.

[0043] A radiation direction or principal beam direction of the illumination is preferably a direction in which the intensity of the light beam is at its maximum or averaged across all directions. These terms preferably refer to the central ray of a beam or its direction. The radiation direction, in particular, indicates the direction of the beam. In the case of a collimated beam, the remaining rays of the beam run essentially parallel to the principal beam direction, so that the principal beam direction is preferably representative of the rays of a beam. In the case of a non-collimated beam, the rays of the beam define a solid angle, at the center of which lies the principal beam direction.

[0044] The center of gravity angle preferably has an analogous meaning, wherein the direction of radiation from the holographic structure is preferably measured as an angle with the surface normal of the holographic structure.

[0045] The fact that the holographic structure is configured to generate the holographic illumination function when illuminated by the lighting arrangement primarily means that the reflective holographic structure's acceptance spectrum, acceptance angle, and acceptance angle spectrum are matched to the illumination of the lighting arrangement. This ensures that the spectrum, illumination angle (or center-of-mass angle), and angular spectrum of the illumination from the lighting arrangement can effectively and / or efficiently produce the holographic illumination function. Advantageously, the acceptance spectrum, acceptance angle, and acceptance angle spectrum of the reflective holographic structure and the spectrum, illumination angle, and angular spectrum of the illumination from the lighting arrangement coincide or overlap. This allows for the provision of an effective and / or efficient lighting system.

[0046] In a further preferred embodiment of the invention, the side door frame section is a front side door frame section, in particular an extension of an A-pillar towards the vehicle floor or a lower section of the B-pillar.

[0047] Front and rear are preferably defined in relation to the direction of travel. For a front door, a front side door frame section is preferably an extension of an A-pillar towards the vehicle floor; for a rear door, it is preferably a lower section of the B-pillar. The side door frame section is preferably particularly well-suited for housing the lighting assembly. This can be kept very compact and is visible only when the door is open, while otherwise remaining protected.

[0048] In a further preferred embodiment of the invention, the side door frame section is a rear side door frame section, in particular a lower section of a B-pillar towards the vehicle floor or an extension of a C-pillar towards the vehicle floor. In the case of a front door, a lower section of the B-pillar is preferably a rear side door frame section, and in the case of a rear door, preferably an extension of a C-pillar towards the vehicle floor. The rear door frame section is advantageous for reduced soiling of the lighting assembly and easier maintenance.

[0049] In a further preferred embodiment of the invention, two lighting arrangements are included, one being located in a front side door frame section and the other in a rear side door frame section. This allows for particularly intense and improved lighting.

[0050] In a preferred embodiment of the invention, the door frame comprises at least one lighting arrangement with at least one separately switchable light source, which is configured for an animated holographic lighting function.

[0051] With a suitable combination, it would also be possible to display an animation or an animated (dynamically changing) holographic lighting function in monochrome or (more) colored or white.

[0052] This embodiment is particularly suitable when using two lighting arrangements, preferably one in a front side door frame section and one in a rear side door frame section. Each lighting arrangement can comprise several separately switchable light sources.

[0053] Preferably, the brightness of the light source is adjustable. This allows for special lighting effects and warning functions, particularly in conjunction with the aforementioned embodiment.

[0054] The aforementioned embodiments may include a control device, e.g. in the form of an integrated circuit.

[0055] According to the invention, the lighting arrangement and the holographic entry strip are arranged relative to each other for illuminating the holographic entry light at a center of gravity angle which corresponds to a Brewster angle of the holographic entry strip or deviates from the Brewster angle by less than 10°, in particular less than 5°.

[0056] Illumination with the Brewster angle can preferably reduce unwanted, undiffracted reflections at the surface of the holographic entry light. Even with unpolarized light, this preferably suppresses at least the reflection of light polarized parallel to the plane of incidence.

[0057] If, for example, unpolarized LEDs are used as the light source, a 50:50 mixture of perpendicularly (TE) and parallel (TM) polarized light is preferably present. At the Brewster angle, preferably 50% of the light (the TM, i.e., the portion polarized parallel to the plane of incidence) is not reflected at all, but penetrates the medium, e.g., the plastic cover of the embossed hologram described above.

[0058] Preferably, the overall efficiency of the system, and in particular the sum of TE + TM, is important. Advantageously, the angle of incidence is chosen such that the sum of the reflection coefficients from TE + TM is as low as possible.

[0059] In the range of 0–20° angle of incidence (center of gravity angle), 4% would be ideal, for example. However, this would require the light to come from above, which has structural disadvantages, such as a large distance between the lighting assembly and the door sill. At a preferred angle of incidence of 70°, for example, over 30% is reflected, which would be undesirable. The Brester angle is preferably located between these values ​​for unpolarized light – here, at least the TM (transient response) would be 0% – and thus represents a good compromise for unpolarized light.

[0060] For determining the Brewster angle, it can be assumed that the entry sill is surrounded by air under standard conditions, in particular air according to ISO 2533.

[0061] In a further preferred embodiment of the invention, the lighting arrangement is configured for illuminating the holographic structure with an angular spectrum around a center-of-mass angle, such that at least 30% of the light rays of the lighting arrangement, in particular at least 40% of the light rays of the lighting arrangement, illuminate the holographic structure, wherein preferably the intensity distribution of the illumination light is homogeneous and in particular has a ratio of minimum intensity (or minimum illuminance or irradiance) to maximum intensity (or maximum illuminance or irradiance) greater than 0.8.

[0062] This allows for an improved holographic illumination function. It is often particularly desirable that the holographic structure is illuminated as homogeneously as possible, while essentially avoiding the creation of unwanted "bright spots" next to the holographic structure.

[0063] In a further preferred embodiment of the invention, the lighting arrangement includes a beam-shaping component. This allows for improved illumination and, for example, advantageous influence on collimation, center of gravity angle, and angular spectrum.

[0064] In a further preferred embodiment of the invention, the lighting arrangement comprises an anamorphic freeform lens as a beam-shaping component, the shape of which is preferably determined by the dimensioning of the holographic structure and / or the arrangement of the lighting arrangement and the holographic entry light relative to each other.

[0065] Since the aspect ratio of entry strips is preferably large (very long, narrow), the beam-shaping optics should have anamorphic properties for high efficiency (i.e., preferably different focal lengths in the horizontal and vertical directions, i.e., in particular, different curvatures in the x and y directions). The necessary ratio advantageously results from the hologram size and the angle at which the hologram is illuminated.

[0066] Preferably, it is a freeform lens which has anamorphic properties and does not necessarily have to have symmetries about arbitrary axes.

[0067] The lens may have certain symmetries, but these can be eliminated if the goal is to achieve the most homogeneous illumination possible.

[0068] In particular, such a lens can be used to ensure that at least 30% of the light rays of the illumination arrangement, and in particular at least 40% of the light rays of the illumination arrangement, illuminate the holographic structure, preferably with a homogeneous intensity distribution of the illumination light and in particular having a ratio of minimum intensity (or minimum illuminance or irradiance) to maximum intensity (or maximum illuminance or irradiance) greater than 0.8.

[0069] In a further preferred embodiment of the invention, the lighting arrangement has a biconical lens as a beam-shaping component, the shape of which is preferably determined by the dimensioning of the holographic structure and / or the arrangement of the lighting arrangement and the holographic entry light relative to each other.

[0070] The beam shaping optics can be a lens, with the light output coupling side having the shape of a biconical surface.

[0071] In particular, such a lens can be used to ensure that at least 30% of the light rays of the illumination arrangement, and in particular at least 40% of the light rays of the illumination arrangement, illuminate the holographic structure, preferably with a homogeneous intensity distribution of the illumination light and in particular having a ratio of minimum intensity (or minimum illuminance or irradiance) to maximum intensity (or maximum illuminance or irradiance) greater than 0.8.

[0072] In a further preferred embodiment of the invention, the lighting arrangement is configured for illuminating the holographic entry strip with an angular spectrum of less than 5°, in particular less than 2°. This allows particularly sharp images to be produced without double images or smearing.

[0073] In a further preferred embodiment of the invention, the lighting arrangement comprises at least one polarized light source, preferably at least one laser or at least one LED with a polarizing filter, wherein the polarization of the light emitted by the light source is preferably polarized substantially parallel to the plane of incidence. Preferably, the illumination is performed at a Brewster angle. This further reduces unwanted reflections.

[0074] In a further preferred embodiment of the invention, the light source of the lighting arrangement comprises at least one LED, in particular at least one predominantly non-polarized LED. This embodiment is particularly cost-effective and efficient.

[0075] In a further preferred embodiment of the invention, the light source of the lighting arrangement comprises at least one monochromatic light source which emits light essentially in one color spectrum.

[0076] In a further preferred embodiment of the invention, the light source of the lighting arrangement comprises at least one multicolored light source and / or several monochromatic light sources of different colors, so that light is emitted in more than one color spectrum. For example, white light can be produced with a combination of a red (R), a green (G) and a blue (B) light source.

[0077] In a further preferred embodiment of the invention, the light source of the lighting arrangement comprises red, green, and blue light. This is a particularly simple source of white light to implement, which can be mass-produced.

[0078] In a further preferred embodiment of the invention, the light source of the lighting arrangement comprises white light. This is a particularly material-saving implementation of a white light source.

[0079] In a further preferred embodiment of the invention, the holographic entry strip and / or the holographic structure has a rectangular shape along its planar extent, in particular with a long and a short side. Such an entry strip has a special aesthetic effect and is particularly well suited for the holographic representation of lettering.

[0080] In a further preferred embodiment of the invention, the at least one holographic structure is configured to generate at least one holographic illumination function for at least a portion of the spectral range emitted by the light source, preferably using different holographic structures for different spectral ranges. This allows a multispectral illumination function with improved optical quality to be provided.

[0081] In a further preferred embodiment of the invention, several differently colored light sources are arranged one above the other in the lateral door frame section, and the at least one holographic structure is configured to generate the illumination function of the respective light source at the respective color and / or at the respective illumination angle. This allows for a particularly narrow illumination arrangement. The illumination angle preferably corresponds to the center of gravity angle.

[0082] In a further preferred embodiment of the invention, the lighting arrangement is configured for illuminating the holographic structure with an intensity gradient, in particular from the center to the edge and / or along a long and / or short side of the planar holographic structure.

[0083] For example, a decrease in intensity can be implemented towards a peripheral area and / or a central area of ​​the holographic structure.

[0084] Intensity profiles within or through the holographic structure can be controlled in two ways. First, by varying the efficiency of the holographic structure. For example, it can be varied from 100% (all light is extracted) to 50% (half the light is extracted). However, in this case, some of the light illuminating the holographic structure is not used because it is not diffracted. Second, the illumination arrangement can be configured to illuminate the holographic structure with a gradient of intensity. For example, the holographic structure is illuminated inhomogeneously by suitable beam shaping (e.g., from 100% to 50% intensity). In this case, the holographic structure preferably exhibits an efficiency of 100% everywhere, meaning all light is diffracted (if, for example, zeroth order is disregarded).This design, which is geared towards illumination with a gradient intensity, allows for a defined intensity profile while simultaneously maximizing efficiency. At the same time, it enables the creation of special lighting functions.

[0085] In a further preferred embodiment of the invention, the lighting arrangement has no beam-shaping component, wherein the light source comprises at least one LED with an emitter area of ​​up to 1 mm x 1 mm. This is a particularly simple embodiment that still results in good illumination and optical quality.

[0086] In a further preferred embodiment of the invention, the viewing area is arranged to ensure that the holographic lighting function is visible to the driver, the passenger, a person entering the vehicle, and / or a person exiting the vehicle. This allows the effectiveness of the door sill trim to be particularly high due to the good visibility of the holographic lighting function.

[0087] In particular, several viewing areas are included, e.g., for the visibility of the holographic lighting function by the driver, the passenger, a person entering the vehicle, and / or a person exiting the vehicle. Different motifs can also be displayed for different viewing areas, e.g., through different holographic structures, such as in a stack or through a multiplex hologram.

[0088] In another preferred embodiment of the invention, the door frame and the lighting arrangement are configured to switch the light source on when the door is opened and off when the door is closed. This can be achieved, for example, using sensors and an integrated circuit. This increases efficiency and improves the lifespan of the lighting arrangement.

[0089] In a further preferred embodiment of the invention, the lighting arrangement and / or the holographic entry strip has a protective element to prevent contamination when the door is closed, in particular a rubber lip and / or a rubber skirt which at least partially covers the lighting arrangement and / or the holographic entry strip when the door is closed. The rubber lip and / or rubber skirt are preferably designed such that they provide a contamination-proof cover for the lighting arrangement and / or the holographic entry strip when the door is closed, but are released when the door is open. This embodiment requires particularly little maintenance.

[0090] Preferably, when opening, the rubber lip or rubber apron can "wipe" over the lighting arrangement and / or the holographic entry strip, thus achieving cleaning.

[0091] In a further preferred embodiment of the invention, the surface of the holographic entry strip and / or the lighting arrangement is designed to provide a lotus effect against surface soiling.

[0092] The lotus effect refers to the property of low wettability of a surface, as seen in the lotus plant. This can be achieved, for example, through water-repellent micro- and / or nanostructured surfaces. This results in improved maintenance and a longer service life.

[0093] Also described herein is a holographic entry strip, designed for use in a door frame as described in this document.

[0094] It is evident to those skilled in the art that the advantages, definitions and embodiments of the door frame according to the invention also apply to the entry strip described herein.

[0095] Also described herein is a system consisting of a holographic entry strip and lighting arrangement, designed for use in a door frame as described in this document.

[0096] It is evident to those skilled in the art that the advantages, definitions and embodiments of the door frame according to the invention and / or the entry strip described herein also apply to the system according to the invention described herein. Description of the invention:

[0097] The invention will be explained below with reference to further figures and examples. The examples and figures serve to illustrate preferred embodiments of the invention without limiting them. The door sill trim is only visible when the door is opened. The door frame and door sill trim are always static relative to each other – only the door moves relative to them. The door frame should accommodate one or more LEDs with (or without) suitable beam-shaping optics. The beam-shaping optics should be adapted to illuminate the hologram as optimally as possible. If these LEDs are RGB, then white light falls on the hologram, allowing it to display a white image. The hologram's eyebox can be directed towards the driver, passenger, or a person outside the vehicle (e.g., standing in front of the door). The LEDs could only activate when the door is opened. To holographically display a white image, the holographic structure must be designed for at least three colors as an RGB hologram. To enable a floating effect (i.e.,To achieve a clean image reproduction (the holographic motif is intended to float a few centimeters above the actual door sill) and simultaneously ensure precise illumination of the hologram, defined lighting is required. The current installation space (3 mm depth) does not provide enough room for such complex lighting within the door sill. LEDs for illumination are located in the door frame. These LEDs can be monochromatic, RGB, or white. The arrangement can include one or more monochromatic LEDs, one RGB LED, or one white LED to display multiple colors or white. The LEDs are positioned so that the hologram is illuminated at an angle corresponding to Brewster's angle ϑB (alternatively ϑB ± 5° or ϑB ± 10°). (→ Center of gravity angle).This arrangement is advantageous for illuminating the holograms, as it minimizes disruptive reflections (and allows maximum light penetration into the hologram material). With multiple LEDs arranged vertically, different center-of-gravity angles result for the holograms (e.g., ϑR, ϑG, ϑB). The holograms are each designed to reconstruct as efficiently as possible at their respective center-of-gravity angles. To achieve a floating height of the hologram motif while maintaining a clear image, the use of reflection holograms is advantageous, as the strong filtering effect is inherent in reflection holograms. Only a clean, defined reference illumination is required. Figure 1 shows the front entry area of ​​a car with an entry sill. Figure 2 shows the front entry area of ​​a car with an illuminated holographic door sill. Figure 3shows the spectrum of a lighting setup with a typical RGB LED light source. Figure 4 shows the basic structure of a door frame with a lighting arrangement without a beam-shaping component. Figure 5 shows a detailed view of the light rays of the lighting arrangement without a beam-shaping component and the illuminated reflective holographic structure. Figure 6 showed an intensity distribution (illuminance) of the illumination rays on the holographic structure in an illumination arrangement without a beam-shaping component. Figure 7 shows the angular spectrum (luminous intensity) of the illumination of the reflective holographic structure in an illumination arrangement without a beam-shaping component. Figure 8 shows the basic structure of a door frame with a lighting arrangement with a beam-shaping component, as well as a section showing a magnification of the lighting arrangement. Figure 9showed an intensity distribution (illuminance) of the illumination rays on and directly next to the holographic structure in an illumination arrangement with a beam-shaping component. Figure 10 shows the angular spectrum of the illumination (luminous intensity) of the reflective holographic structure in an illumination arrangement with a beam-shaping component. Figure 11 schematically shows the illumination of the holographic structure at a suitable center-of-mass angle. Figure 12 schematically shows the illumination of the holographic structure in an illumination arrangement with several RGB light sources stacked on top of each other, illuminating the holographic structure at a suitable center-of-mass angle. Figure 13 The holographic structure is shown as an embossed hologram with a red cover, which essentially only does not absorb the red light of a multicolored spectrum.

[0098] Figure 1shows a front entry area of ​​a car with an entry sill. 1 in a lower door frame section 13.

[0099] Figure 2 shows the front entry area of ​​a car with an illuminated holographic door sill. 1, which is a holographic structure 3 features the holographic lighting function 4 The lighting arrangement is used when the light is on 5 generated, which is housed in a front side section of the door frame. The holographic lighting function 4 It can be a font that floats above the entry bar 1.

[0100] Figure 3 This shows the spectrum of a lighting setup with a typical RGB LED light source. The following suitable LEDs are shown: Monochrome LEDs: Osram Synios P2720 KS DMLN31.23 (super red, λdom = 632 nm, Φ = 25 Im) KT DMLN31.23 (true green, λdom = 528 nm, Φ = 25 Im) KB DMLN31.13 (blue, λdom = 455 nm, Φ = 10 Im) "RGB" LED combination: Osram MultiLED LRTB GVSG LRTB GVSG red (λdom = 625 nm, Φ = 2.01 Im) LRTB GVSG green (λdom = 528 nm, Φ = 4.48 Im) LRTB GVSG blue (λdom = 460 nm, Φ = 0.92 Im) Not shown is the equally suitable "white light" LED: Osram Synios P2720 KW DMLN32 SB

[0101] Figure 4 shows the basic structure of a door frame 9 with a lighting arrangement 5 without a beam-shaping component. The door frame has an A-pillar. 15 and a B-pillar 17 on. The holographic structure 3 is located in the lower door frame section 13 and is positioned at an angle to the light rays of the lighting arrangement 5 without beam-shaping component 7 illuminated. The lighting arrangement is located in the rear side section of the door frame.11, which part of the B-pillar 17 is, because it is a front door.

[0102] Figure 5 shows a detailed view of the light rays of the lighting arrangement without a beam-shaping component. 7 and the illuminated reflective holographic structure 3.

[0103] Figure 6 The figure shows the intensity distribution (illuminance) of the illumination rays on the holographic structure in an illumination setup without a beam-shaping component. The unit is lux [Ix], and the scale ranges from 0 Ix to 39.8 Ix. It is evident that the illumination is very homogeneous.

[0104] Figure 7This shows the angular spectrum of the illumination (illuminance is shown as a function of the horizontal and vertical angles) of the reflective holographic structure in an illumination setup without a beam-shaping component. The angular spectrum is not very large, even though no beam-shaping component is used.

[0105] Figure 8 shows the basic structure of a door frame 9 with a lighting arrangement 5 with beam-shaping component 23 as well as a section showing a magnified view of the lighting arrangement 5. It can be seen that the light rays of the lighting arrangement have a beam-shaping component. 19 optimally adapted to the holographic structure 3 are aligned. This can be achieved in particular by using a [missing information] directed towards the light source. 21 (here an LED) arranged anamorphic (freeform) lens as beam-shaping component 23,which is optimally shaped in relation to the requirements.

[0106] Figure 9 showed an intensity distribution (illuminance) of the illumination rays on and directly next to the holographic structure 3 In a lighting arrangement with a beam-shaping component, it can be seen that both the homogeneity lies within the range described above and that essentially only the holographic structure is affected. 3 (at least 40% of the total illumination intensity). The shown dimension ranges from -50 mm to +50 mm in the x-direction (horizontal axis) and from -10 mm to +10 mm in the y-direction (vertical axis). The intensity scale shown (cd) ranges from 0 to 2.47 x 10³ cd.

[0107] Figure 10This shows the angular spectrum of the illumination (illuminance is shown as a function of the horizontal and vertical angles) of the reflective holographic structure in an illumination setup with a beam-shaping component. The angular spectrum is even smaller than without the use of the beam-shaping component.

[0108] Figure 11 schematically shows the door frame 9 with illumination of the holographic structure 3 along a direction of illumination 25 under a suitable center of gravity angle 27.

[0109] Figure 12 schematically shows the illumination of the holographic structure. 3 in a lighting arrangement 5 with multiple RGB light sources stacked on top of each other, which project the holographic structure along a respective lighting direction 25 (blue), 25' (green) 25" (red) at a suitable center of gravity angle 27 (blue), 27'(green) 27" (red) light up.

[0110] Figure 13 shows the holographic structure 3 as an embossed hologram 33 with a red cover 29 (The color is represented in the image by diagonal hatching from the bottom left to the top right.) Daylight or ambient light encompasses a broad spectrum, including blue along one direction of illumination. 25, green along a direction of illumination 25' and red along a direction of illumination 25". Of course, other lighting directions are also included in daylight or ambient light, but these are not diffracted or are diffracted differently than the one shown. The light beam 31, which is not absorbed by the cover and is diffracted by the hologram, is here only the desired red light in the example shown, which generates the holographic illumination function. REFERENCE MARK LIST

[0111] 1 Entry sill 3 Reflective holographic structure 4 Holographic lighting function 5 Lighting arrangement 7 Light rays of the lighting arrangement without beam-shaping component 9 Door frame 11 Rear side door frame section 13 Lower door frame section 15 A-pillar 17 B-pillar 19 Light rays of the lighting arrangement with beam-shaping component 21 Light source (LED) 23 Beam-shaping component 25 Lighting direction (main beam direction) 27 Center of gravity angle of the lighting 29 Red cover of an embossed hologram 31 Light ray diffracted by the hologram and not absorbed by the cover 33 Embossed hologram

Claims

1. Door frame (9) for a vehicle, having a holographic door sill strip (1) in a lower door frame section (13), wherein the holographic door sill strip (1) comprises a planar element having a thickness perpendicular to the planar extent of at most 3 mm, which has at least one planar, reflective holographic structure (3) that is configured to generate a holographic light function (4) in a field of view, having an illumination arrangement (5) that is arranged in at least one lateral door frame section and is configured to illuminate the holographic door sill strip (1), comprising at least one light source (21), wherein the holographic structure (3) is configured to generate the holographic light function (4) when illuminated by the illumination arrangement (5), wherein the illumination arrangement (5) and the holographic door sill strip (1) are arranged relative to one another for the illumination of the holographic door sill strip (1) at a centroid angle (27) which corresponds to a Brewster angle of the holographic door sill strip (1) or deviates by less than 10° from the Brewster angle.

2. Door frame (9) according to the preceding claim, wherein the holographic structure (3) comprises a volume hologram, which is preferably present as a hologram stack or as a multiplexed hologram, or wherein the holographic structure (3) comprises an embossed hologram (33).

3. Door frame (9) according to the preceding claim, wherein the embossed hologram (33) is included in an element (29) which is configured to predominantly absorb a part of the visible spectrum that is not intended to contribute to the generation of the holographic light function (4).

4. Door frame (9) according to the preceding claim, wherein the lateral door frame section is a front lateral door frame section, in particular an extension of an A-pillar (15) toward the vehicle floor or a lower section of the B-pillar (17), and / or wherein the lateral door frame section is a rear lateral door frame section (11), in particular a lower section of a B-pillar (17) toward the vehicle floor or an extension of a C-pillar toward the vehicle floor.

5. Door frame (9) according to the preceding Claim 4, wherein two illumination arrangements (5) are comprised, in each case in a front lateral door frame section and a rear lateral door frame section (11).

6. Door frame according to one or more of the preceding claims, wherein the centroid angle (27) deviates by less than 5° from the Brewster angle.

7. Door frame (9) according to one or more of the preceding claims, wherein the illumination arrangement (5) is configured to illuminate the holographic structure (3) with an angular spectrum around a centroid angle (27), with the result that at least 30% of the light rays from the illumination arrangement (5), in particular at least 40% of the light rays from the illumination arrangement (5), light the holographic structure (3), wherein an intensity distribution of the illumination light is preferably homogeneous and in particular has a ratio of minimum intensity to maximum intensity of greater than 0.8.

8. Door frame (9) according to one or more of the preceding claims, wherein the illumination arrangement (5) has an anamorphic free-form lens as the beam-shaping component part (23), the shape of which preferably results from the dimensioning of the holographic structure (3) and / or the arrangement of the illumination arrangement (5) and the holographic door sill strip (1) relative to one another, or wherein the illumination arrangement (5) has a biconical lens as the beam-shaping component part (23), the shape of which preferably results from the dimensioning of the holographic structure (3) and / or the arrangement of the illumination arrangement (5) and the holographic door sill strip (1) relative to one another.

9. Door frame (9) according to one or more of the preceding claims, wherein the light source (21) of the illumination arrangement (5) comprises at least one multicoloured light source (21) and / or a plurality of monochromatic light sources (21) each having a different colour, so that light in more than one colour spectrum is emitted, wherein the light source (21) of the illumination arrangement (5) preferably comprises red, green and blue light.

10. Door frame (9) according to one or more of the preceding claims, wherein the at least one holographic structure (3) is configured to generate at least one holographic light function (4) for at least some of the spectral range emitted by the light source (21), wherein different holographic structures (3) are preferably used for different spectral ranges.

11. Door frame (9) according to one or more of the preceding claims, wherein a plurality of differently coloured light sources (21) are arranged one above the other in the lateral door frame section and the at least one holographic structure (3) is configured to generate the holographic light function (4) of the respective light source (21) with the respective colour and / or at the respective illumination angle (27).

12. Door frame (9) according to one or more of the preceding claims, wherein the field of view is arranged so that the holographic light function (4) can be seen by the driver, the front passenger, a person entering the vehicle, and / or a person exiting the vehicle.

13. Door frame (9) according to one or more of the preceding claims, wherein the illumination arrangement (5) and / or the holographic door sill strip (1) has a dirt protection element protecting against dirt when the door is closed, in particular a rubber lip and / or a rubber apron, which at least partially covers the illumination arrangement (5) and / or the holographic door sill strip (1) when the door is closed, and / or wherein the surface of the holographic door sill strip (1) is configured for a lotus effect against soiling of the surface.