Lighting device, display device, user terminal device and waveguide assembly

Abstract

Lighting device (200) for a display device (250), wherein the lighting device (200) comprises a waveguide arrangement (100), a first light source (210) and a second light source (212), wherein the waveguide arrangement (100) comprises a first diffractive structure (60) configured as a first diffuser (60') and a second diffractive structure (62) configured as a second diffuser (62'), the waveguide arrangement (100) comprises a first coupling section (51) for coupling light (80a) from the first light source (210) and a second coupling section (53) for coupling light (80b) from the second light source (212) into the waveguide arrangement (100) and an output coupling section (55) for coupling light (80) out of the waveguide arrangement (100) into a first viewing area (110) and into a second viewing area (120), the first The diffractive structure (60) is set up toLight (80a) coupled into the first coupling section (51) is coupled out into the first viewing area (110) which is designed as an eyebox (110'), and the second diffractive structure (62) is configured to couple out light (80b) coupled into the second coupling section (53) in a limited manner through the second viewing area (120).

Description

The present disclosure relates to a lighting device for a display device. The disclosure further relates to a display device, a user terminal, and a waveguide assembly.Display devices are known from the prior art. Typically, a display device includes a pixel array and an illumination device. The illumination device is configured to illuminate the pixel matrix, and the pixel matrix is configured to selectively transmit light of the illumination device from the illumination device through the pixel matrix and to make a representation resulting from the transmitted light visually perceptible to a viewer in a spatially defined viewing region.A comparatively large viewing range can result in a user being able to perceive a representation generated by the display device from different angles. In certain applications, for example for entertainment, a large viewing range may be desirable in order to make the display visually perceptible to the user under only a slight influence of his position.In other applications, on the other hand, a comparatively small viewing area may be desirable, for example if the display comprises sensitive information and / or if the display is intended to be accessible to a user who is typically arranged at a specific location relative to the display device. The latter may apply, for example, to a display device in a vehicle. In this case, the display device is typically installed in the vehicle in a stationary manner. A driver of the vehicle, who is typically seated on one of the seats of the vehicle and has a typical posture, is thus located in a viewing region that can be comparatively sharply delimited relative to the display device.In general, there may be so-called private information which may be relevant to a user of the display device in a first viewing area and the output of which is to be restricted to the first viewing area. Other so-called public information can be relevant to a plurality of users of the display device in a second viewing region and should accordingly be visually perceptible. Further applications are conceivable.Such differentiation of the application cases may make it necessary for the lighting device to be switchable in order to switch between different modes or modes of operation in order to enable information to be presented in the different viewing areas alternatively or simultaneously.The object is to enrich the prior art and to provide improved illumination of a display device. An embodiment of the disclosure may achieve the object of providing effective and switchable illumination for a display device.The object is achieved by the subject matters of the independent claims. Optional developments of the disclosure are disclosed by dependent patent claims, the following description and the figures.According to an aspect of the disclosure, a lighting device for a display device is provided. In this case, the illumination device comprises a waveguide arrangement, a first light source and a second light source, wherein the waveguide arrangement comprises a first diffractive structure designed as a first diffuser and a diffractive structure designed as a second diffuser, the waveguide arrangement has a first coupling section for coupling light from the first light source and a second coupling section for coupling light from the second light source into the waveguide arrangement and a coupling section for coupling light from the waveguide arrangement out into a first viewing region and into a second viewing region, the first diffractive structure is designed to couple light coupled into the first coupling section out into the first viewing region designed as an eyebox, and the second diffractive structure is designed to couple light coupled into the second coupling section out through the second viewing region in a limited manner.The illumination device can be configured to illuminate a component of the display device, for example a pixel matrix. For this purpose, the lighting device has the first light source and the second light source. In order that the lighting device can provide different operating modes of the display device, the lighting device has the waveguide arrangement into which light emitted by the first light source and / or by the second light source can be coupled.The waveguide arrangement can be referred to as multi-channel and thereby provides a plurality of mutually different transmission modes, i.e. channels, for light in order to be able to couple out the light of the first light source and the light of the second light source in a differentiated manner. In this case, the multichannel waveguide arrangement can couple light into the first viewing region in a first transmission mode and couple light into the second viewing region in a second transmission mode.In order that the light coupled out of the waveguide arrangement can be coupled out into the respectively spatially extended first viewing region and / or second viewing region, the waveguide arrangement has the first diffractive structure and the second diffractive structure, which are designed as diffusers. The first diffractive structure and the second diffractive structure can be illuminated by light coupled into the waveguide arrangement, diffracting light, coupling it out of the waveguide and thereby scattering it. By the dispersed decoupling of the light, the spatially extended viewing areas can be formed.In this case, the first diffractive structure is configured to couple out light coupled into the first coupling section into the first viewing region, and the second diffractive structure is configured to couple out light coupled into the second coupling section in a limited manner through the second viewing region. The first diffractive structure can thus be efficient for the light of the first light source and the second diffractive structure can be efficient for the light of the second light source. Here, "efficient" denotes that the respective diffractive structure can diffract light incident on the diffractive structure and deflect it by diffraction.The first viewing region is designed as an eyebox. An eyebox can be defined as a volume, in particular a frustoconical volume, from which light coupled out from the coupling-out section can be viewed, wherein no coupled-out light can be viewed outside the volume. The eyebox can thus provide a sharply delimited first viewing region. The eyebox can thereby define a sharp boundary between a region with a visible representation by the display device and a region in which the representation visible in the eyebox is not visible. The first viewing region can also form a plurality of eye boxes different from one another.It was recognized that the first diffractive structure enables the first viewing region to be formed as an eyebox. The display of an eyebox is not possible, or is possible only with additional outlay, with a diffuser which is based on scattering. The first diffractive structure can effectively achieve a restricted and sharply demarcate first viewing range. By coupling out the light by means of the first diffractive structure, this is possible effectively as a first viewing region, i.e. without substantial optical losses.The lighting device thus achieves the effect that the display device can be operated in two different operating modes that can be switched by the lighting device with the light sources in order to couple out light into the first viewing region embodied as an eyebox and / or couple out light to a limited extent by the second viewing region. In this case, the first viewing area can be, for example, a private viewing area in order to make private information visually perceptible to a user only when the user is looking at the display device from the private first viewing area. The second viewing area can be different from the first viewing area and make information accessible visually perceptible, for example, to a plurality of users, i.e. publicly.Moreover, it can be achieved that the diffractive structures can be used to provide a multichannel waveguide arrangement with a waveguide arrangement or optionally only one waveguide. The need to provide a plurality of substrates which are separate from one another and have different optical properties, into which the light can be coupled, is dispensed with.The second viewing region can comprise the first viewing region configured as an eyebox. In other words, the first viewing region is arranged in the second viewing region. The first viewing range may be smaller than the second viewing range. It is thus possible for the first viewing region to be arranged within the second viewing region. The first viewing area may be used for the representation of private information and the second viewing area may be used for the representation of public information.The second viewing region can be formed as a second eyebox different from the eyebox. This makes it possible for the second viewing area to make private information visually perceptible, for example, to a further user. In this case, the first viewing region can be arranged partially or completely outside the second viewing region.Alternatively or additionally, the first viewing region and the second viewing region can be arranged overlapping one another. The second viewing region can be defined by an opening angle of up to 180°.The first diffractive structure can be arranged in and / or on the decoupling section. That diffractive structure which is configured for decoupling light into the first viewing region can thus be arranged in such a way that the first diffractive structure brings about the deflection of the light before the decoupling. This makes it possible to prevent the light, after being deflected by the first diffractive structure, from striking the second diffractive structure before being decoupled and being diffracted or deflected again. The sharpness of the eyebox or its border can thus be improved. For this purpose, the waveguide arrangement can have a base section arranged at a distance from the decoupling section, and the second diffractive structure can be arranged in and / or on the base section.The first light source, the second light source, the first coupling section and the second coupling section can be configured to couple light into the waveguide arrangement at mutually different angles relative to a plane defining the coupling section. This makes it possible to achieve that light from the first light source is coupled into the waveguide arrangement at a first angle and light from the second light source is coupled into the waveguide arrangement at a second angle different from the first angle. It can thus already be achieved that the light of the first light source falls onto the first diffractive structure at an angle associated with the first angle and is in this case optionally diffracted and deflected, and light of the first light source falls onto the second diffractive structure at an angle associated with the second angle and is in this case optionally diffracted and deflected. This enables an effective embodiment of the waveguide arrangement, in particular if the light of the first light source and the light of the second light source are coupled into the waveguide arrangement in the same plane. In this case, the first diffractive structure is configured to redirect the light coupled into the waveguide arrangement at the first angle and to couple it out into the first viewing region, and the second diffractive structure is configured to redirect the light coupled into the waveguide arrangement at the second angle and to couple it out into the second viewing region.The first diffractive structure and the second diffractive structure can each have a deflection efficiency with an efficiency maximum, wherein the efficiency maximum of the first diffractive structure is set up for deflecting and decoupling the light coupled into the first coupling section by the first light source, and the efficiency maximum of the second diffractive structure is set up for deflecting and decoupling the light coupled into the second coupling section by the first light source, into the second viewing region. This allows efficient decoupling of light into the viewing regions to be achieved.The first diffractive structure and the second diffractive structure can each have a deflection efficiency with an efficiency maximum in a red, green and blue spectral range. Thus, the first diffractive structure and the second diffractive structure can be efficient for diffracting and deflecting white light. Thus, the first light source and the second light source can each have a white light source, for example an RGB LED. The first diffractive structure and the second diffractive structure can have deflection efficiencies that are different from one another in order to be able to diffract and deflect the light of the first and the second light source differently.The first light source, the second light source, the first coupling section and the second coupling section can be configured to couple light into the waveguide arrangement in such a way that the light is at least partially totally reflected in the waveguide arrangement. In particular, the light can be totally reflected in the coupling-out section and / or the coupling-in section or at a respective boundary layer between the coupling-out section and / or the coupling-in section and air. This enables light to strike one of the diffractive structures and in this case to be deflected according to the diffraction properties of the respective diffractive structure and to be totally reflected and / or transmitted and totally reflected. In particular, transmitted and totally reflected light can propagate further through the waveguide arrangement in order to provide uniform illumination, i.e. uniform coupling out of light in the coupling-out section.The first diffractive structure and / or the second diffractive structure can form a holographic diffuser. A holographic diffuser may be a diffuser that diffuses light incident on the diffuser by diffraction. The holographic diffuser can effectively achieve a well-defined scattering by diffraction, in order to enable, for example, a sharply delimited eyebox as the first viewing region. A holographic diffuser can have a particularly high transmission efficiency and enable a compact design.The first diffractive structure and the second diffractive structure can have an angle-dependent deflection efficiency with an efficiency maximum and with a width, wherein width of the deflection efficiency of the first diffractive structure is smaller than the width of the second diffractive structure. This makes it possible to achieve that the first viewing region can be surrounded by the second viewing region.The first diffractive structure and the second diffractive structure can each have a sectionally different angle-dependent deflection efficiency. This makes it possible to achieve uniform coupling of light out of the waveguide arrangement. In this case, the waveguide arrangement can be divided into sections, and in the sections, the first diffractive structure has an angle-dependent deflection efficiency which differs depending on the section, and the second diffractive structure has an angle-dependent deflection efficiency which differs depending on the section. A reduction in the intensity of the light coupled out in one section can thus be counteracted by coupling out in a further section on an optical path between the respective light source and the section.The angle-dependent deflection efficiency of the first diffractive structure may depend on a distance to the first coupling-in section and / or the angle-dependent deflection efficiency of the second diffractive structure may depend on a distance to the second coupling-in section. In this case, the distance can be, for example, the optical path length of the light coupled into one of the coupling sections between the respective coupling section and a section of the coupling-out section and / or of the waveguide arrangement in which the light is coupled out of the waveguide arrangement. The distance can be related to the number of total reflection of the light in the waveguide arrangement and / or to the quantity of light already coupled out. It was recognized here that typically the intensity of the light can be dependent on the distance, and a distance-dependent deflection efficiency can compensate a possible dependence of the intensity in such a way that the decoupling of the light is adjustable, for example homogeneous in the decoupling section.The first diffractive structure can have a plurality of diffractive structure elements arranged in sections with deflection efficiency which is angle-dependent according to a respective one of the sections. In this case, each of the sections or each of the structural elements can have a distance from a coupling section. Increasing the efficiency of the diffractive structure elements from the coupling section with distance can enable homogeneous decoupling.The diffractive structure elements can be arranged adjacent to one another and / or overlapping one another. This makes it possible to achieve homogeneous coupling out of light. By arranging the structural elements adjacently and / or in an overlapping manner, continuous, i.e. spatially uninterrupted, decoupling can be achieved.The waveguide arrangement can have a waveguide having the first diffractive structure and the second diffractive structure. A particularly effective construction of the waveguide arrangement can thus be achieved with the avoidance of boundary layers. Alternatively, the waveguide arrangement can have a waveguide arrangement with more than two diffractive structures in order to be able to provide more than two viewing regions. Furthermore, the waveguide arrangement can alternatively have a plurality of waveguides which are separate from one another, for example separated by an air gap, wherein each of the waveguides has a diffractive structure.The waveguide can consist of a silicate glass and / or a polymer. Thus, the waveguide may provide a substrate in which light can propagate through the waveguide under total reflection.The first light source and the waveguide arrangement can be configured such that the light coupled into the first coupling-in section has a plurality of illumination sections assigned to the coupling-out section, wherein the plurality of illumination sections form a contiguous illumination surface. The illumination sections, so-called "footprints", can contact one another in order to form a continuous illumination surface and thus enable a homogeneous coupling of light out of the waveguides. Alternatively, the illumination sections can overlap, which can lead to bright areas, i.e. more coupled-out light, and / or the illumination sections can have a distance, which can lead to darker areas, i.e. less coupled-out light. In the case of touching and / or overlapping of the illumination sections, geometric considerations play a role in particular. For example, for a direct contact of the illumination sections, it can be the case that tan θ=0.5*f / d, wherein θ is the angle that the coupled-in light beam encloses with a normal of the boundary surface (reflection surface) of the waveguide (preferably in a plane along a longitudinal section of the waveguide, i.e. a section along the light conducting direction or a longitudinal direction of the waveguide). Thus, θ can be the first angle for light coupled into the first coupling section and / or the second angle for light coupled into the second coupling section. F is the extension of the illumination section along this light conducting or longitudinal direction and d is the thickness of the waveguide. This applies in particular to waveguides whose boundary surfaces at which the reflection takes place are parallel.In another embodiment, the first coupling-in section does not have to be designed as an eyebox. In other words, an illumination device for a display device can accordingly be provided, wherein the illumination device comprises a waveguide arrangement, a first light source and a second light source, wherein the waveguide arrangement comprises a first diffractive structure formed as a first diffuser and a diffractive structure formed as a second diffuser, the waveguide arrangement has a first coupling section for coupling light from the first light source and a second coupling section for coupling light from the second light source into the waveguide arrangement and a decoupling section for decoupling light from the waveguide arrangement into a first viewing region and into a second viewing region, the first diffractive structure is configured to decouple light coupled into the first coupling section into the first viewing region, and the second diffractive structure is configured to couple light coupled into the first coupling section, Light coupled into the second coupling section can be coupled out to a limited extent through the second viewing region, wherein the first light source and the waveguide arrangement are configured such that the light coupled into the first coupling section has a plurality of illumination sections assigned to the coupling-out section, wherein the plurality of illumination sections form a contiguous illumination surface. In this case, the first light source and the waveguide arrangement can be configured such that the illumination sections touch one another. The other embodiment can thus form a coherent illumination surface even without coupling light out into a private viewing region and thus enable homogeneous coupling of light out of the waveguide. The other embodiment may include one or more of the features described as optional or advantageous and with respect to an aspect of the disclosure to achieve a related technical effect.In another embodiment, a coupling section and a diffractive structure are provided. The second coupling section and the second diffractive structure are thus unnecessary. In addition, the first viewing region does not have to be designed as an eyebox. In other words, an illumination device for a display device can accordingly be provided, wherein the illumination device comprises a waveguide arrangement and a light source, wherein the waveguide arrangement comprises a diffractive structure, the waveguide arrangement has a coupling section for coupling light from the light source and a decoupling section for decoupling light from the waveguide arrangement into a viewing region, the diffractive structure is configured to decouple light coupled into the coupling section into the viewing region, wherein the light source and the waveguide arrangement are configured such that the light coupled into the coupling section has a plurality of illumination sections assigned to the decoupling section, wherein the plurality of illumination sections form a contiguous and / or overlapping illumination surface. In this case, the light source and the waveguide arrangement can be configured such that the illumination sections touch one another. The other embodiment may include one or more of the features described as optional or advantageous and with respect to an aspect of the disclosure to achieve a related technical effect. In this case, what applies in particular to the coupling-in section, to the diffractive structure, to the viewing region and / or to the light source is that respectively described correspondingly with reference to the first and / or second coupling-in section, to the first and / or second diffractive structure, to the first and / or second viewing region and / or to the first and / or second light source. In particular, geometric considerations can play a role in touching and / or overlapping the illumination sections as described above. For example, for a direct contact of the illumination sections, it may be the case that tan θ=0.5*f / d, wherein θ, f and d may be defined as described above. Furthermore, the diffractive structure can be designed as a diffuser. Additionally or alternatively, the diffractive structure can be configured to generate a real and / or virtual image in the viewing region. The diffractive structure can comprise and / or be a volume hologram, for example.The first light source and the waveguide assembly according to an aspect of the disclosure may be configured such that the illumination portions contact each other. Touching the illumination sections can reduce the formation of inhomogeneous, for example lighter and / or darker, sections. For this purpose, the waveguide arrangement and at least one of the light sources can be configured such that the light propagating through a waveguide of the waveguide arrangement is reflected in a base section of the waveguide at a first point and an envelope of the light propagating through the waveguide intersects at a second point, and the first point and the second point fall on top of one another.The lighting device may include a controller for operating the first light source and the second light source, and the controller may be configured to operate only the first light source in a first operation mode and to operate the first light source and the second light source in a second operation mode. The illumination device can thus be operated in a plurality of modes, which leads to a visual perceptibility of a user from one of the viewing regions in each case. For example, a user may perceive information from the first viewing area in the first operating mode, but not outside the first viewing area; and a user may perceive information from the second viewing area in the second operating mode.According to an aspect of the disclosure, a display device is provided. In this case, the display device comprises the above-described illumination device, wherein the pixel matrix and the waveguide arrangement are configured to couple light coupled out of the coupling-out section into the pixel matrix. The illumination device can have one or more of the features described above in order to achieve a technical effect associated therewith.According to an aspect of the disclosure, a user terminal is provided. The user terminal comprises the above-described lighting device and / or the above-described display device. In this case, the lighting device and / or the display device can have one or more of the features described above in order to achieve a technical effect associated therewith.Alternatively or additionally, a motor vehicle can be provided. The motor vehicle comprises the above-described lighting device and / or the above-described display device. In this case, the lighting device and / or the display device can have one or more of the features described above in order to achieve a technical effect associated therewith. The display device can form a head-up display as a transmission mode, for example, wherein the display device is configured to display a representation visually perceptible to a driver of the motor vehicle in the first viewing region formed as an eyebox in the first transmission mode, and is configured to display a visually perceptible representation for entertainment occupants of the motor vehicle optionally different from the driver in another transmission mode. This makes it possible to ensure that the driver is provided with information relevant to the driving and at the same time is not distracted by the entertainment displayed to the other occupants.According to an aspect of the disclosure, a waveguide arrangement for a lighting device is provided. In this case, the waveguide arrangement comprises a waveguide, a first diffractive structure designed as a first diffuser and a second diffractive structure designed as a second diffuser, wherein the waveguide has a first coupling section for coupling light from a first light source and a second coupling section for coupling light from a second light source into the waveguide and a decoupling section for decoupling light from the waveguide into a first viewing region and into a second viewing region, the first diffractive structure is configured to decouple light coupled into the first coupling section into the first viewing region designed as an eyebox, and the second diffractive structure is configured to couple out light coupled into the second coupling section in a limited manner through the second viewing region. In this case, the waveguide arrangement can have one or more of the features of the waveguide arrangement described above in order to achieve a technical effect associated therewith.Exemplary embodiments of the disclosure are described below. The following are shown: FIG. 1 is a schematic illustration of a user terminal with a lighting device according to an aspect of the disclosure; FIG. 2 is a schematic illustration of a user terminal with a lighting device according to an aspect of the disclosure; FIG. 3 is a detail of a schematic illustration of a lighting device according to an aspect of the disclosure; FIG. 4 is a detail of a schematic illustration of a waveguide arrangement according to an aspect of the disclosure; FIG. 5 is a schematic illustration of a waveguide arrangement according to an aspect of the disclosure with a first light source; FIG. 6 is a schematic illustration of a waveguide arrangement according to an aspect of the disclosure with a first light source; and FIG. 7 shows a schematic illustration of a deflection efficiency of a diffractive structure of a waveguide arrangement according to one aspect of the disclosure with a first light source.FIG. 1 shows a schematic illustration of a user terminal 270 with a lighting device 200 according to an aspect of the disclosure. The user terminal 270 is, for example, a mobile telephone, a smart device, for example a smart watch and / or a wearable, a portable computer and / or a screen or monitor. Instead of the user terminal 270, FIG. 1 could also show a motor vehicle (not shown).The user terminal 270 of FIG. 1 comprises a display device 250 having a lighting device 200 and a pixel array 260. The pixel array 260 includes a plurality of pixels (not shown) individually actuatable to selectively transmit light 80 a, 80 bthrough the pixel array 260. The illumination device 200 is configured to illuminate the pixel array 260, i.e. to emit light 80 a, 80 bin the direction of the pixel array 260. For this purpose, the illumination device 200 and the pixel matrix 260 are arranged in a layer structure. Illuminating the pixels of the pixel array 260 may result in transmission of light 80 a, 80 bthrough the pixel array 260, which may result in a visually perceptible representation. The representation can thereby comprise information in the form of image and / or text. The pixel matrix 260 can be formed, for example, as in a liquid crystal display (LCD), as in a display with organic light-emitting diode display (OLED display) and / or as in a display with quantum dot light-emitting diodes (QLED display). In another embodiment, any other display may be used instead of the pixel array 260.The lighting device 200 includes a first light source 210 and a second light source 212. The first light source 210 and the second light source 212 are configured to emit light 80 a, 80 bin a spectrum of wavelengths.In particular, the light sources 210, 212 are configured to emit light 80 a, 80 bwith different spectral components. The light sources 210, 212 emit light 80 a, 80 bin a red, green and blue spectral range, respectively, and thus effectively white light 80 a, 80 b. The light sources 210, 212 are white light sources. The light sources 210, 212 are, for example, light emitting diodes (LEDs). The light 80 amitted from the first light source 210 is shown by a solid line. The light 80 bmitted from the second light source 212 is shown with a dashed line.The lighting device 200 has a control unit 220 for operating the first light source 210 and the second light source 212. The control device 220 is configured to apply electrical energy to the light sources 210, 212 in order for the light sources 210, 212 to emit light 80 a, 80 b. In this case, the control unit 220 is configured to operate only the first light source 210 in a first operating mode M 1 and to operate the first light source 210 and the second light source 212 in a second operating mode M 2 (see also description of FIG. 3 ).The lighting device 200 comprises a waveguide arrangement 100. The waveguide arrangement 100 comprises a waveguide 50. Components of the waveguide 50 are thus included in the waveguide arrangement 100. The waveguide 50 is made of a silicate glass and / or a polymer. The waveguide 50 can be manufactured, for example, from a glass, in particular a borosilicate glass, and can have a refractive index in the range from 1.45 to 1.5, which is only weakly dependent on the wavelength L in the spectral range S.The waveguide 50 includes a first coupling portion 51 for coupling light 80 afrom the first light source 210 into the waveguide 50 and a second coupling portion 53 for coupling light 80 bfrom the second light source 212 into the waveguide 50.The waveguide 50 comprises an output section 55 for outputting light 80 a, 80 bfrom the waveguide 50. The decoupling section 55 is arranged such that light 80 a, 80 bcoupled from the waveguide arrangement 100 propagates to the pixel matrix 260 in order to illuminate the pixel matrix 260. The decoupling section 55 can extend substantially in a plane 59 which is arranged parallel to the pixel matrix 260.The first light source 210, the second light source 212, the first coupling section 51 and the second coupling section 53 are configured to couple light 80 a, 80 binto the waveguide 50 at mutually different angles 81, 82 relative to the plane 59 defining the coupling section 55. More specifically, the light 80 aof the first light source 210 is coupled into the first coupling section 51 at a first angle 81 into the waveguide 50, and the light 80 bof the second light source 212 is coupled into the waveguide 50 at a second angle 82. In this case, the first angle 81 and the second angle 81, 82 are defined relative to a plane 59 defining the decoupling section 55.The waveguide 50 has a first diffractive structure 60 embodied as a first diffuser 60' and a second diffractive structure 62 embodied as a second diffuser 62'. The first diffractive structure 60 and the second diffractive structure 62 each form a holographic diffuser 60', 62'. The first diffractive structure 60 is a transmission hologram 60" and the second diffractive structure 62 is a reflection hologram 62". In another embodiment, each of the diffractive structures 60, 62 can be a transmission hologram and / or a reflection hologram, wherein a total reflection at an interface between the waveguide and air can be utilized. Each of the diffractive structures 60, 62 can also comprise two reflection holograms and form a so-called Z hologram as a transmission structure.The diffractive structures 60, 62 are configured to redirect light 80 a, 80 bcoupled into the coupling sections 51, 53 and incident on the diffractive structures 60, 62, as a function of a direction of incidence of the incident light 80 a, 80 band a wavelength of the light 80 a, 80 b, as described in more detail with reference to FIG. 3.In FIG. 1, the first diffractive structure 60 is arranged in and / or on the decoupling section 55. The waveguide 50 has a base section 56 arranged at a distance from the decoupling section 55. The second diffractive structure 62 is arranged in and / or on the base section 56.The first diffractive structure 60 is configured to couple light 80 acoupled into the first coupling section 51 out of the waveguide arrangement 100 via the coupling section 55 into the first viewing region 110 configured as an eyebox 110'. The first viewing region 110 is spatially sharply delimited as eyebox 110'. Within the first viewing region 110, a representation based on the light 80 acoupled into the first coupling section 51 is visually perceptible by the display device 250. Outside the first viewing region 110, a representation based on the light 80 acoupled into the first coupling section 51 is not perceptible or is visually perceptible to a reduced extent by the display device 250.The second diffractive structure 62 is configured to couple out light 80 bcoupled into the second coupling section 53 in a limited manner by the second viewing region 120. The second viewing region 120 can be spatially sharply delimited (see FIG. 2 ) or such a delimitation can be dispensed with, as illustrated in FIG. 1 by the second viewing region 120 indicated schematically by the dashed line. The first viewing region 110 is arranged in the second viewing region 120. The second viewing region 120 comprises the first viewing region 110 configured as an eyebox 110'. Within the second viewing region 120, a representation based on the light 80 bcoupled into the second coupling section 53 is visually perceptible by the display device 250. The second viewing region 120 can be defined by an opening angle of up to approximately 180°.The first coupling section 51 and the second coupling section 53 are configured to couple the light 80 of the first light source 210 and of the second light source 212 into the waveguide arrangement 100 in such a way that the light 80 a, 80 bis at least partially totally reflected in the waveguide arrangement 100. The light 80 a, 80 bmay thus propagate through the waveguide 50 until the light 80 a, 80 bis incident on one of the diffractive structures 60, 62, deflected and coupled out. The redirecting and decoupling of the light 80 a, 80 bis also described in more detail with reference to FIGS. 3 and 4.As schematically illustrated in FIG. 1, the light 80 aof the first light source 210 coupled in at the first angle 81 propagates through the waveguide 50 in such a way that the first diffractive structure 60 diffracts, deflects and couples out the light 80 aand into the first viewing region 110. The light 80 bof the second light source 212 coupled in at the second angle 82 propagates through the waveguide 50 in such a way that the second diffractive structure 62 diffracts, deflects and couples out the light 80 band into the second viewing region 120.The first diffractive structure 60 and the second diffractive structure 62 each have a deflection efficiency 400 with an efficiency maximum 401 a, 401 bin each case in a red, green and blue spectral range. A schematic illustration of a deflection efficiency 400 with only one efficiency maximum 401 a, 401 bfor simplification is shown in FIG. 7.In an embodiment not shown, the waveguide arrangement 100 can have a plurality of waveguides 50 each having one or more diffractive structures 60, 62. In an embodiment not shown, the waveguide arrangement 100 can provide more than two diffractive structures 60, 62, in order to be able to provide a number of channels or viewing regions 110, 110', 120 corresponding to the number of structures 60, 62.FIG. 2 shows a schematic illustration of a user terminal 270 with a lighting device 200 according to an aspect of the disclosure. The user terminal 270 of FIG. 2 will be described with reference to FIG. 1 and the description thereof. Here, the differences of the user terminal 270 of FIG. 1 and the user terminal 270 of FIG. 2 will be described.The second viewing region 120 is formed as a second eyebox 120' different from the eyebox 110', wherein the first viewing region 110 is not surrounded by the second viewing region 120. In other words, the first viewing region 110 and the second viewing region 120 are arranged in a complementary manner to one another or in a non-overlapping manner.In an embodiment not shown, the second viewing region 120 can partially comprise the first viewing region 110, i.e. the first viewing region 110 has a section arranged inside the second viewing region 120 and a section arranged outside the second viewing region 120.In another embodiment (not shown), the first viewing region 110 does not necessarily have to be formed as an eye box 110'.FIG. 3 shows a detail of a schematic illustration of a lighting device 200 according to an aspect of the disclosure. In this case, FIG. 3 illustrates the propagation of light 80 a, 80 bthrough a waveguide 50 of a waveguide arrangement 100 of a lighting device 200 as described with reference to FIGS. 1 and 2. FIG. 3 will be described with reference to FIGS. 1 and 2.In this case, FIG. 3 illustrates in particular the propagation of light 80 a, 80 bthrough the waveguide 50 and the diffracting of light 80 a, 80 bthrough the diffractive structures 60, 62 and decoupling of light 80 a, 80 bfrom the waveguide 50.The waveguide 50 has the base section 56 and the decoupling section 59. The base section 56 and the decoupling section 59 are arranged parallel and spaced apart from one another. The base section 56 and the decoupling section 59 are each arranged at an interface between the waveguide 50 and the environment, for example made of air and / or a material having a lower refractive index than the waveguide 50. Thus, light 80 a, 80 b propagating through the waveguide 50 can either be coupled out or totally reflected.Since the light 80 bis diffracted by the second diffractive structure 62 and can be deflected in a plurality of directions, the light 80 bmay be deflected by the second diffractive structure 62 in the direction of the first diffractive structure 60 and diffracted again, deflected and optionally coupled out by the first diffractive structure 60. Therefore, in the embodiment of FIG. 3, in which the second viewing region 120 comprises the first viewing region 110 as described with reference to FIG. 1, it is advantageous to arrange the second diffractive structure 120, which is configured for coupling out light 80 bto the second viewing region 120, in such a way that the second diffractive structure 62 is arranged in the base section 56 spaced apart from the coupling-out section 59. If a representation in the first viewing area 110 is to be achieved ("private mode"), the second light source 212 is deactivated and the first light source 210 is activated. Thus, only the first diffractive structure 60 is efficient for the light of the first light source 210.The first diffractive structure 60 arranged on the decoupling section 55 (so-called "private mode diffuser") has a narrow angle spectrum, as illustrated by the arrows at the first diffractive structure 60 illustrating the decoupled light 80 aand the associated circle sectors. In other words, the diffractive structure 60 has a deflection efficiency 400 with a narrow width 402 a, 402 a', 402 a". For a private mode representation, the lighting device is operated in the first operating mode M 1, wherein the first light source 210 is activated and the second light source 212 is deactivated. The angular ranges of different sections of the first diffractive structure 60 are different from each other to define a sharp eyebox 110' in cooperation.The second diffractive structure 62 arranged on the base section 56 (so-called "public mode diffuser") has a broad angle spectrum, as illustrated by the arrows illustrating the deflected light 80 bat the second diffractive structure 62 and the associated circle sector. If only the second light source 212 is operated for a representation in the second viewing region 120 (so-called "public mode") and deflection takes place by the second diffractive structure 62, a part of the angle spectrum diffracted by the second diffractive structure 62 is likewise diffracted by the first diffractive structure 60 and can thus be filtered out, since the second diffractive structure 62 is efficient at incidence of light from two sides onto the diffractive structure 62. This filtered-out angle spectrum corresponds to the angle spectrum of the first diffractive structure 60. Therefore, for a representation in public mode, both diffractive structures 60, 62 have to be illuminated, i.e. the illumination device is operated in the second operating mode M 2, wherein the first light source 210 and the second light source 212 are operated. The resulting angle spectrum of the display device can be composed of the individual angle spectra of the diffractive structures 60, 62.Since both light sources 210, 212 are operated in public mode, the brightness of the first light source 210 can be adapted, in particular reduced, in order to achieve substantially homogeneous brightnesses of the representation within the first viewing region 110 and the second viewing region 120 in public mode.The intensity of the light 80 a, 80 bby decoupling depends on the distance d of the point at which the light 80 a, 80 bis decoupled from the coupling section 51, 53 at which the light 80 a, 80 bis coupled into the waveguide 50, the first diffractive structure 60 and the second diffractive structure 62 each have an angle-dependent deflection efficiency 400 that is different in sections. In this case, the angle-dependent deflection efficiency 400 of the first diffractive structure 60 depends on the distance d to the first coupling-in section 51, and the angle-dependent deflection efficiency 400 of the second diffractive structure 62 depends on the distance d to the second coupling-in section 53. For example, the respective diffractive structure 60, 62 can couple out less light 80 a, 80 bfrom the waveguide 50 in proportion to the respective coupling-in section 51, 53 than further from the respective coupling-in section 51, 53 in order to achieve a homogeneous intensity of the coupled-out light 80 a, 80 b.FIG. 4 shows a detail of a schematic illustration of a waveguide arrangement 100 according to an aspect of the disclosure. FIG. 4 will be described with reference to FIGS. 1 to 3.FIG. 4 illustrates a beam path within the waveguide 50 It is assumed here that light 80 a, 80 b arriving from different directions propagates through the waveguide at the same angle in terms of absolute value. In this case, the light 80 a, 80 bmay be totally reflected at a boundary layer of the waveguide 50 with the beam path illustrated with a solid line, whereby the second diffractive structure 62 may be efficient for the light 80 a, 80 brriving from the different directions. As a result, the light 80 a, 80 bmay be diffracted and deflected by the second diffractive structure 62 with the beam path illustrated with a solid line. In this case, the light 80 a, 80 bmay be coupled out of the waveguide 50 with the beam path illustrated by a solid line. Therefore, the first angle 81 and the second angle 82 are to be selected to be different from one another in order to reduce and / or avoid the decoupling of light 80 a, 80 bin the base section 56.FIG. 5 shows a schematic illustration of a waveguide arrangement 100 according to an aspect of the disclosure with a first light source 210. FIG. 5 will be described with reference to FIGS. 1 to 4. The waveguide arrangement 100 according to FIG. 5 differs from the waveguide arrangements 100 according to FIGS. 1 to 4 in the geometry of the waveguide 50 and of the first coupling section 51; in this case, the second coupling section 53 and the second light source 212 are not shown in FIG. 5 for the sake of better illustration. The description with reference to the first coupling-in section 51 in FIG. 5 also applies to the second coupling-in section 53, not shown.The first coupling-in section 51 has a first height h1as an extension. The first height h 1 is an extension of the waveguide 50 perpendicular to the decoupling section 59. parallel to the decoupling section 59, the waveguide 50 has the first height h 1 up to a width w. The width w is an extension of the waveguide 50 parallel to the decoupling section 59. At a distance from the coupling section 51 by more than the width w, the waveguide 50 has a second height h 2, which is different from the first height h 1 and a further extension of the waveguide 50 is perpendicular to the decoupling section 59.The first coupling section 51 is illuminated by the first light source 210. If the heights h 1, h 2, the width w and the arrangement of the light sources 210, 212 are selected as desired, the waveguide 50 may not fully illuminate the decoupling region 59. The geometry of the waveguide 50 and the arrangement of the first light source 210 are such that the light 80 acoupled into the first coupling-in section 51 has a plurality of illumination sections 57 (so-called "footprints") assigned to the coupling-out section 55. Each of the decoupling sections 55 has an extent L and two adjacent decoupling sections 55 are arranged spaced apart from one another at a distance D. The distance D may appear like a region without light 80 a, i.e. a dark stripe. The beam path and in particular the distance D resulting therefrom can be characterized by two points P 1, P 2. The first point P1 is the first point of reflection within the waveguide 50 at the base portion 59 of the path of light 80a indicated by the dot-dash line. The second point P 2 is the first intersection point within the waveguide 50 of the beam path of the light 80 aindicated by the dot-dashed line and of the beam path of the light 80 aindicated by the dashed line, that is to say an intersection point of an envelope 85 or of a light bundle of the light 80 amitted by the first light source 210 and coupled into the waveguide 50. The points P 1, P 2 fall apart, which leads to the distance D between the decoupling sections 55.In order to diffract and redirect the light 80 ato be coupled out, the first diffractive structure 60 has a plurality of diffractive structure elements 65 arranged in sections 66. The diffractive structure elements 65 have an angle-dependent deflection efficiency 400 dependent on the respective one of the sections 66, in particular the arrangement of the section 66. Thus, uniform coupling of light 80a out of the waveguides 50 can be achieved in the spaced apart portions 66. In order to avoid spacing of the structural elements 65, the geometry of the waveguide arrangement 100 can be adapted as described with reference to FIG. 6. Furthermore, the waveguide arrangement 100 according to FIG. 5 can also be formed in such a way that the first viewing region 110 is not formed as an eyebox 110'. Optionally and alternatively, in particular the second coupling section 53 and the second diffractive structure 62 are unnecessary.FIG. 6 shows a schematic illustration of a waveguide arrangement 100 according to an aspect of the disclosure with a first light source 210. FIG. 6 will be described with reference to FIG. 5.According to FIG. 6, the light source 210 and the waveguide 50 are configured such that the plurality of illumination sections 57 form a continuous illumination surface 58. Two adjacent illumination sections 57 thereby touch one another. The diffractive structure elements 65 are arranged adjacent to one another.In order to increase the illumination sections 57 by an expansion difference DL compared to FIG. 5, the first angle 81 for coupling in the light 80 aof the first light source 210 can be kept constant; at the same time, the second height h 2 can be reduced by a second height difference dh 2 and the width w can be reduced by a width difference dw, alternatively, the first height h 1 can be increased by a first height difference dh 1.Alternatively, in order to increase the illumination portions 57 by an expansion difference DL compared to FIG. 5, the first angle 81 for coupling the light 80 aof the first light source 210 may be changed; thereby, the first angle 81 and the width w may be increased or the first angle 81 and the width w may be decreased.The beam path of the light 80 acan thus be influenced in such a way that the points P 1, P 2 coincide. Thus, the illumination portions 57 can be enlarged so as to make the distance D between adjacent illumination portions 57 zero, i.e., two adjacent illumination portions 57 contact each other.In this case, the light 80 acan be collimated by a collimator 215 before coupling in, in order to achieve homogeneity of the illumination. Alternatively or additionally to the collimator 215, the distance between the light source 210, 212 and the collimator 215 can be adjusted and / or a deflection hologram can be provided instead of the collimator 215 or additionally to the collimator 215.In other words, the waveguide arrangement 100 and the first light sources 210 are configured such that the light 80 apropagating through the waveguide 50 is first reflected in the base section 56 at the first point P 1 and the envelope 85 of the light 80 apropagating through the waveguide 50 intersects at the second point P 2, and the first point P 1 and the second point P 2 fall on top of one another.FIG. 6 is an example of a geometry of the waveguide arrangement 100 in which two adjacent illumination sections 57 touch one another. The fact that two adjacent illumination sections 57 touch one another can also be achieved by waveguide arrangements 100 having different geometries with respect to the waveguides 50 and / or the light sources 210, 212. For example, the waveguide 50 can have a geometry of a trapezoid as shown in FIGS. 1 to 3, wherein the coupling sections 51, 53 and the light sources 210, 212 are to be formed and / or arranged in accordance with uniform illumination.The waveguide arrangement 100 according to FIG. 6 can also be configured in such a way that the first viewing region 110 is not configured as an eyebox 110'. Optionally and alternatively, in particular the second coupling section 53 and the second diffractive structure 62 are unnecessary.FIG. 7 shows a schematic illustration of a deflection efficiency 400 of a diffractive structure 60, 62 of a waveguide arrangement 100 according to an aspect of the disclosure. FIG. 7 illustrates only schematically a deflection efficiency 400 or an angle spectrum of the diffractive structures 60, 62 described with reference to FIGS. 1 to 6 as a function of an angle a, in each case for a point of the diffractive structures 60, 62.It should be noted with respect to FIG. 7 that the diffractive structures 60, 62 are each configured to redirect white light 80 a, 80 b. For this purpose, the respective deflection efficiency 400 of the diffractive structures 60, 62 has, for example, a plurality of efficiency maxima 401 a, 401 b, for example in each case an efficiency maximum 401 a, 401 bin a red, green and blue spectral range as illustrated in FIG. 7.In this case, FIG. 7 schematically shows the deflection efficiency 400 aof the first diffractive structure 60 with a dashed line and the deflection efficiency 400 bof the second diffractive structure 62 with a solid line by way of example for a spectral range corresponding to a color. The deflection efficiency 400 aof the first diffractive structure 60 has an efficiency maximum 401 aand the deflection efficiency 400 bof the second diffractive structure 62 has an efficiency maximum 401 b. Around the respective efficiency maximum 401 a, 401 b, the deflection efficiency 400 a, 400 bfalls to approximately zero in the schematically shown examples. The drop in the deflection efficiency 400 a, 400 bcan be characterized by a width 402 a, 402 b. The first diffractive structure 60 and the second diffractive structure 62 thus have the width 402 a, 402 b, wherein width 402 aof the deflection efficiency 400 of the first diffractive structure 60 is smaller than the width 402 bof the second diffractive structure 62. The first diffractive structure 60 can thus deflect light 80 a, 80 binto a small spatial region than the second diffractive structure 62. The width 402 aof the first diffractive structure 60 defines, in this case, taking into account refraction of the light 80 on exiting from the waveguide 50, point by point an opening angle of the light 80 decoupled from the decoupling section 55, which angle contributes to a representation in the first viewing region 110. The width 402 bof the second diffractive structure 62, taking into account refraction of the light 80 when exiting from the waveguide 50, defines point by point an opening angle of the light 80 coupled out of the coupling-out section 55, which contributes to a representation in the second viewing region 120, wherein an opening angle of approximately 180° advantageously results.Reference Sign (Part of Description)50 Waveguide 51 First coupling-in section 53 Second coupling-in section 55 Coupling-out section 56 Base section 57 Illumination section 58 Illumination surface 59 Plane 60 First diffractive structure 60' Holographic diffuser 60" Transmission hologram 62 Second diffractive structure 62' Holographic diffuser 62" Reflection hologram 65 Diffractive structural element 66 Section 80 a, 80 bLight 81 First angle 82 Second angle 85 Envelope 100 Waveguide arrangement 110 First viewing region 110' Eyebox 120 Second viewing region 120' Eyebox 200 Illumination device 210 First light source 212 Second light source 215 Collimator 220 Control device 250 Display device 260 Pixel matrix 270 User terminal 400, 400 a, 400 b Umlenk efficiency 401 a Effizienz maximum 401 b Effizienz maximum 402 a, 402 a', 402 a" Width 402 b Breite a Angle d Distance D Distance dh 1, dh2height difference DLthe expansion difference dwthe width difference h1, h2height Lthe expansion P1, P2dot wthe width

Claims

Illumination device (200) for a display device (250), wherein - the illumination device (200) comprises a waveguide arrangement (100), a first light source (210) and a second light source (212), wherein - the waveguide arrangement (100) comprises a first diffractive structure (60) formed as a first diffuser (60') and a second diffractive structure (62) formed as a second diffuser (62'), - the waveguide arrangement (100) comprises a first coupling section (51) for coupling in light (80a) from the first light source (210) and a second coupling section (53) for coupling in light (80b) from the second light source (212) into the waveguide arrangement (100) and a coupling section (55) for coupling out light (80a, 80b) from the waveguide arrangement (100) into a first viewing region (110) and into a second viewing region (120), - the first diffractive structure (60) is configured to couple out light (80a) coupled into the first coupling section (51) into the first viewing region (110) configured as an eyebox (110'), and - the second diffractive structure (62) is configured to couple out light (80b) coupled into the second coupling section (53) in a limited manner by the second viewing region (120).The lighting device (200) according to claim 1, wherein the second viewing area (120) comprises the first viewing area (110) configured as an eyebox (110').The lighting device (200) according to claim 1 or 2, wherein the second viewing region (120) is formed as a second eye box (120') different from the eye box (110').Illumination device (200) according to one of the preceding claims, wherein the first diffractive structure (60) is arranged in and / or on the decoupling section (55).The illumination device (200) according to one of the preceding claims, wherein the waveguide arrangement (100) has a base section (56) arranged at a distance from the decoupling section (55), and the second diffractive structure (62) is arranged in and / or on the base section (56).The lighting device (200) according to any one of the preceding claims, wherein the first light source (210), the second light source (212), the first coupling section (51) and the second coupling section (53) are configured to couple light (80a, 80b) into the waveguide arrangement (100) at mutually different angles (81, 82) relative to a plane (59) defining the coupling section (55).The illumination device (200) according to one of the preceding claims, wherein the first diffractive structure (60) and the second diffractive structure (62) each have a deflection efficiency (400) with an efficiency maximum (401a, 401b), wherein the efficiency maximum (401a) of the first diffractive structure (60) is configured to deflect and couple out the light (80a) coupled into the first coupling section (51) from the first light source (210) into the first viewing region (110), and the efficiency maximum (401b) of the second diffractive structure (62) is configured to deflect and couple out the light (80b) coupled into the second coupling section (53) from the first light source (212) into the second viewing region (120).The illumination device (200) according to one of the preceding claims, wherein the first diffractive structure (60) and the second diffractive structure (62) each have a deflection efficiency (400) with an efficiency maximum (401a, 401b) in each case in a red, green and blue spectral range.The lighting device (200) according to any one of the preceding claims, wherein the first light source (210), the second light source (212), the first coupling section (51) and the second coupling section (53) are configured to couple light (80a, 80b) into the waveguide arrangement (100) such that the light (80a, 80b) is at least partially totally reflected in the waveguide arrangement (100).The illumination device (200) according to one of the preceding claims, wherein the first diffractive structure (60) and / or the second diffractive structure (62) forms a holographic diffuser (60', 62').The illumination device (200) according to one of the preceding claims, wherein the first diffractive structure (60) and the second diffractive structure (62) have an angle-dependent deflection efficiency (400) with an efficiency maximum (401a, 401b) and with a width (402a, 402b), wherein width (402a) of the deflection efficiency (400) of the first diffractive structure (60) is smaller than the width (402b) of the second diffractive structure (62).Illumination device (200) according to one of the preceding claims, wherein the first diffractive structure (60) and the second diffractive structure (62) each have an angle-dependent deflection efficiency (400) which is different in sections.The illumination device (200) according to claim 12, wherein the angle-dependent deflection efficiency (400) of the first diffractive structure (60) depends on a distance (d) to the first incoupling section (51) and / or the angle-dependent deflection efficiency (400) of the second diffractive structure (62) depends on a distance (d) to the second incoupling section (53).Illumination device (200) according to Claim 12 or 13, wherein the first diffractive structure (60) has a plurality of diffractive structure elements (65) arranged in sections (66) with a deflection efficiency (400) which is angle-dependent according to a respective one of the sections (66).The lighting device (200) according to claim 14, wherein the diffractive structure elements (65) are arranged adjacent to each other and / or overlapping each other.The illumination device (200) according to one of the preceding claims, wherein the waveguide arrangement (100) comprises a waveguide (50) having the first diffractive structure (60) and the second diffractive structure (62).The lighting device (200) according to claim 16, wherein the waveguide (50) is made of a silicatic glass and / or a polymer.The lighting device (200) according to any one of the preceding claims, wherein the first light source (210) and the waveguide arrangement (100) are configured such that the light (80a) coupled into the first coupling-in section (51) comprises a plurality of illumination sections (57) assigned to the coupling-out section (55), wherein the illumination sections (57) form a contiguous illumination surface (58).The lighting device (200) according to claim 18, wherein the first light source (210) and the waveguide arrangement (100) are configured such that the lighting portions (57) contact each other.The lighting device (200) according to any one of the preceding claims, wherein the lighting device (200) comprises a control device (220) for operating the first light source (210) and the second light source (212), and the control device (220) is configured to operate only the first light source (210) in a first operating mode (M1) and to operate the first light source (210) and the second light source (212) in a second operating mode (M2).Display device (250) comprising an illumination device (200) according to one of the preceding claims and a pixel matrix (260), wherein the pixel matrix (260) and the waveguide arrangement (100) are configured to couple light (80a, 80b) coupled out from the coupling-out section (55) into the pixel matrix (260).A user terminal (270) comprising a lighting device (200) according to any one of claims 1 to 20 and / or a display device (250) according to claim 21.Waveguide arrangement (100) for an illumination device (200), preferably according to one or more of the preceding claims 1 to 20, wherein - the waveguide arrangement (100) comprises a first diffractive structure (60) formed as a first diffuser (60') and a second diffractive structure (62) formed as a second diffuser (62'), - the waveguide arrangement (100) has a first coupling section (51) for coupling light (80a) from a first light source (210) and a second coupling section (53) for coupling light (80b) from a second light source (212) into the waveguide arrangement (100) and a decoupling section (55) for decoupling light (80) from the waveguide arrangement (100) into a first viewing region (110) and into a second viewing region (120), - the first diffractive structure (60) is configured to couple light (80) from a second light source (212) into the waveguide arrangement (100), Light (80a) coupled into the first coupling section (51) is coupled out into the first viewing region (110) formed as an eyebox (110'), and - the second diffractive structure (62) is configured to couple out light (80b) coupled into the second coupling section (53) in a limited manner through the second viewing region (120).

Images