Display apparatus and system for displaying holograms

Abstract

According to one aspect of the present disclosure, a display device for a public passenger transportation facility to display an image is provided. The display device includes a diffractive film comprising volume gratings and configured to display incident light having a predetermined wavelength within a viewing zone of a certain angle. Further, the display device also includes an imaging light source for emitting light having the predetermined wavelength. The imaging light source is arranged at a distance from the diffractive film and configured to illuminate the diffractive film.

Description

Technical Field

[0001] The present invention relates to a transparent display device that is preferably modifiable and more preferably suitable for public passenger transport vehicles. Background Technology

[0002] Retrofittable displays in public transportation infrastructure can provide additional information and / or entertainment for passengers. However, traditional display systems present numerous challenges in terms of complexity, supply costs, and especially in integrating them into existing infrastructure.

[0003] In traditional public transport facilities (such as vehicles, stations, or platforms), display areas are limited to stand-alone display devices. These devices also compete with the (internal) space available to passengers. Currently, it is nearly impossible to meet the demand for further increases in display area without sacrificing passenger capacity. Therefore, for operators, the space required for current displays, the methods of mounting the displays, and their electrical connections within the facility all pose significant challenges.

[0004] Traditional display panels in public transportation facilities also fail to enable users or passengers to interact with the displayed information.

[0005] In addition, traditional display panels are exposed to harsh environments within the facility. These environments include significant temperature fluctuations, humidity, vibrations caused by weather and / or vehicle movement, and mechanical forces resulting from destructive acts. Summary of the Invention

[0006] Therefore, there is a need for a display device that can be installed or modified in public passenger facilities without sacrificing passenger capacity.

[0007] The purpose of this invention is to provide a display device for a window area that can further ensure high visibility of the window area.

[0008] Another object of the present invention is to provide a display device with the widest possible viewing angle.

[0009] Furthermore, the present invention aims to provide a corresponding system that can be integrated into almost all public transportation vehicles and utilizes existing glass areas as display screens.

[0010] Furthermore, the present invention aims to provide a system capable of interacting with information displayed on a display device.

[0011] Another objective is to provide a display device that is robust enough to be used in public passenger transport facilities.

[0012] At least one of the above objectives can be achieved by the features of the display device as described in independent claim 1 or the features of the corresponding independent system claims. Further developments of the invention are described in the corresponding dependent claims.

[0013] The present invention is based on the concept of providing a display device for public passenger transport facilities, the device being used to display images, wherein the display area can be configured as a transparent diffraction film, and thus can be arranged on the window area of ​​a public passenger transport vehicle without significantly darkening the window.

[0014] According to one aspect of this disclosure, a display device for displaying holograms is provided. The display device includes a diffraction film comprising a volumetric grating and configured to display or guide incident light having a predetermined wavelength to a viewing area at a specific angle. The display device also includes an imaging light source for emitting light having the predetermined wavelength. The imaging light source is arranged at a certain distance from the diffraction film. The imaging light source is configured to directly or indirectly illuminate the diffraction film.

[0015] "Direct illumination" refers to imaging the emitted light onto the diffraction film without deflecting the emitted light beam between the imaging light source and the diffraction film. In certain configurations, indirect illumination can also be used, where the emitted light is deflected by optical elements to illuminate the diffraction film.

[0016] According to another aspect of this disclosure, a system is provided. The system includes public passenger transport facilities, such as carriages, carriage bodies, or vehicle bodies, and / or public passenger transport facilities, such as bus stops or platform displays. The system also includes at least one display device according to the foregoing aspects. An imaging light source is connected to the power supply infrastructure of the object or vehicle body, and / or integrated into its lining.

[0017] The display device of this invention has the following advantages: it can be easily retrofitted, particularly for installation in the passenger compartment of public transport vehicles or their adjacent infrastructure. The diffraction film can be arranged on or over existing traffic areas, such as window areas, luggage storage areas, wall areas, door areas, ceiling areas, and / or windproof areas. The imaging light source can be approximately the size of a cigarette box and can also be easily arranged to illuminate the diffraction film. Therefore, new display areas can be created cost-effectively, especially in public transport vehicles.

[0018] Within the scope of this disclosure, the transport of people by public transport companies is considered public passenger transport. Public passenger transport can include local and long-distance passenger transport. Consideration is given in particular to any type of bus, taxi, highway and urban rail, train, ship, helicopter, and airplane. In one embodiment, the public passenger transport facility can be a rail vehicle. Each mode of transport has a passenger cabin in which the display device of the present invention can be retrofitted, i.e., arranged when the corresponding facility is ready to operate or at least fully manufactured. Similarly, the display device of the present invention can be retrofitted in facilities such as stations, elevators, platforms, etc.

[0019] Based on the disclosures above, the display device and system may also include one or more of the following features.

[0020] The display device may also include an interface with a control unit for receiving image signals. The imaging light source may be configured to emit light representing the image signals.

[0021] The diffraction film may include microstructures introduced by a laser having a predetermined wavelength. The microstructure may include a diffraction structure. The microstructure may include a volume hologram. The microstructure may include a volume grating. Within the scope of this disclosure, a volume hologram may refer to a grating structure in the diffraction film introduced, etched, or exposed by irradiating the diffraction film with coherent laser light of a predetermined wavelength, for example, using a photorefractive effect. The grating structure or volume grating may have a spatially periodic refractive index change in one direction. The grating structure or volume grating may have a predetermined number of Bragg planes. The diffraction film may be formed as a holographic diffuser. The diffraction film may include a holographic film. The diffraction film may form a display panel of a display device. The diffraction film can be modified particularly simply as a mechanical component because no power supply is required.

[0022] The volumetric grating of the diffraction film can have multiple partial gratings. Each partial grating can be introduced by exposure using a laser with a predetermined wavelength. Each partial grating can be designed for a predetermined wavelength with a specific bandwidth (e.g., ±10 nm). These can be, for example, wavelengths of red, green, and blue light. This deflects a multicolor image. The imaging light source is preferably adapted thereto and configured to generate the corresponding color partial images. These color partial images can be generated simultaneously or rapidly and sequentially, so that the viewer perceives them as a multicolor image only in superimposed form.

[0023] Viewers may perceive the image emitted by the imaging light source only within the viewing area. The viewing area may extend in a direction perpendicular to the direction of movement of the public transport facility.

[0024] The display device may also have a holographic filter, for example, as described in DE 10 2021 108 354 A1. This prevents interference light.

[0025] The diffraction film may have a transparency of at least 90%, preferably at least 94%, and particularly preferably 96%. Because of this high transparency, the diffraction film can be applied to window glass without significantly affecting the viewer's visibility. The diffraction film may be a polymer film.

[0026] In this context, "transparency" can refer to transparency within a wavelength range that includes visible light and, optionally, infrared light. The transparency of a diffractive film can be determined by illuminating the film with a collimated beam of known intensity and measuring the transmitted intensity. The ratio of the transmitted intensity to the known intensity, i.e., the total transmittance, represents the degree of transparency of the diffractive film.

[0027] The inventors recognized that window areas in vehicles or public transportation facilities represent a considerable size that has been technically little or unused to date. Due to the high transparency of the diffraction film, large areas can be subsequently retrofitted into conventional vehicles with a display device according to one aspect of the invention. The diffraction film of the display device can be attached, for example, to the surface of the window area of ​​the vehicle or public transportation facility using an adhesive.

[0028] An imaging light source can be positioned on the viewer side of the diffraction film. The viewer side can be the display side of the diffraction film, meaning the imaging light source and the viewer can be located on the same side of the diffraction film. The diffraction film can be configured not to display an image on the side facing away from the imaging light source. The imaging light source can be positioned outside the viewer's field of view. The imaging light source can be positioned in a half-space on the viewer side. The imaging light source can include a laser. That is, the diffraction film and the imaging light source are, for example, positioned inside a vehicle. Therefore, the displayed information can only be recognized from the interior or the interior of the vehicle. When viewed from the outer surface, i.e., from outside the vehicle, the information is not recognizable. However, in certain embodiments, the diffraction film can also be configured to display an image only on the side facing away from the imaging light source. This configuration of the diffraction film can be controlled by a volumetric grating introduced therein.

[0029] The imaging light source can have a direct distance from the center of the diffraction film and a distance from the plane defined by the diffraction film. The direct distance can be a factor ranging from 2 to 5 times larger than this distance. The distance from the plane in this case refers to the imaginary magnified distance from the imaging light source to the film, i.e., this distance is perpendicular to the film, or the distance line is perpendicular to the film. That is, the imaging light source can be offset and arranged outside the diffraction film, but in this case, the diffraction film can still be illuminated. The imaging light source can be arranged closer to the plane defined by the diffraction film than the center of the diffraction film. This arrangement ensures that no viewer can interfere with the optical path between the imaging light source and the diffraction film. This avoids viewer obstruction of the displayed image.

[0030] The imaging light source may include an image generator and a control unit with a processor. The control unit can drive the image generator to generate multicolor images. The image generator can be an LCD module, an OLED module, an LCoS module, or a tilting mirror matrix. Furthermore, the image generator may have a frosted screen.

[0031] Multicolor images can be generated by an image generator, for example, by generating three color portion images with different wavelengths. These could be, for example, a blue portion image with a wavelength of 460 nm, a green portion image with a wavelength of 500 nm, and a red portion image with a wavelength of 640 nm. The color portion images can be generated simultaneously or rapidly alternated in time, so that the viewer only perceives the superimposed multicolor image.

[0032] A beam-shaping optical unit can be arranged between the imaging light source and the diffraction film. The beam-shaping optical unit can reduce the distance between the imaging light source and the diffraction film, particularly the direct distance and / or perpendicular distance. The beam-shaping optical unit allows a relatively large diffraction film to be illuminated by a light source that is relatively close to the diffraction film.

[0033] The imaging light source can be arranged such that the emitted light is incident on the diffraction film at an incident angle of at least 8°. In this configuration, total internal reflection of light on the diffraction film can be avoided.

[0034] A diffraction film and an imaging light source may be arranged on the traffic areas and / or window areas of a public transport facility, particularly on the traffic areas and / or window areas inside a public transport vehicle. The traffic areas and / or window areas may be oriented perpendicular to their direction of movement and / or the direction of movement of the public transport facility. The diffraction film may preferably be arranged on the window area of ​​the vehicle. The diffraction film may be tightly connected to the window area of ​​the vehicle. The diffraction film may be releasably connected to the window area of ​​the vehicle, preferably releasably connected without residue. The imaging light source may preferably be arranged on the ceiling of the vehicle above the diffraction film, and not far from the diffraction film. The diffraction film may preferably include a self-adhesive side, through which it is fixed or attached to the window area. The diffraction film may be configured to be subsequently arranged inside or on the public transport facility, particularly on the (non-windshield) window area of ​​the public transport facility. The diffraction film may be detachably connected to the public transport facility so that the diffraction film can be replaced. The diffraction film may be firmly bonded to the public transport facility, particularly via the self-adhesive side.

[0035] The display device may also include a protective film and / or an anti-reflective film. The protective film and / or anti-reflective film may be disposed on the diffraction film, particularly on the viewer's side or the display side. The protective film protects the diffraction film from mechanical influences from the surrounding environment. Similarly, the protective film prevents the diffraction film from detaching, being damaged, or being removed, or at least makes it significantly difficult to remove. For this purpose, the protective film may have a scratch-resistant surface. The protective film and / or anti-reflective film may be tightly bonded to the diffraction film. The protective film and / or anti-reflective film may be larger than the diffraction film to cover its edges. The protective film and / or anti-reflective film may be constructed in multiple layers to perform various optical and / or mechanical functions. The protective film and / or anti-reflective film may preferably include a self-adhesive side through which it is fixed to the diffraction film and the window area.

[0036] In one embodiment, the display device may include a glass plate, preferably bulletproof glass, positioned in front of the diffraction film on the viewer's side. By shielding the diffraction film with an additional glass plate, the protection of the diffraction film can be significantly improved, particularly against vandalism.

[0037] In addition, the imaging light source may include a protective cover or protective box to protect it from environmental influences and / or destructive acts.

[0038] The diffraction film may have a decoupling angle for displaying the hologram, which differs from the incident angle of the light from the imaging source. Thus, the light from the imaging source can be easily projected at a solid angle visible to a seated and / or standing viewer in the vehicle. The diffraction film may include microstructures configured to display the light from the imaging source at an aperture angle perpendicular to the diffraction film of 30° to 60°, preferably 40° to 50°.

[0039] The display device may also include a control device connected to the imaging light source via a communication channel. The control device may be configured to generate and / or receive image signals and provide the image signals to the imaging light source via the communication channel. The imaging light source may receive the image signals and convert them into light with a predetermined wavelength corresponding to the image signals. The image signals may include control data or source control signals, based on which the imaging light source may emit light. The predetermined wavelength may be selected from a predetermined wavelength range. The image signals may contain instructions for the imaging light source to emit light representing the image signals, wherein the emitted light may be deflected to a viewing area through interaction with a diffraction film. The control device may generate or adjust the image signals independently. The control device may also include an interface for remote control so that the image signals can be provided externally. The image signals may be dynamically adjusted and / or updated. The image signals may be updated remotely wirelessly. In particular, dynamic image sequences, clips, and / or videos may be provided as image signals by updating the image signals and may be deflected to the viewing area through a diffraction film.

[0040] The communication channel can be wireless and / or wired. The imaging light source may include a receiver through which image signals can be received by a control device. The control device may be a central control unit of a public transport vehicle. Alternatively, the control device may be arranged in a common housing with the imaging light source.

[0041] The display device may also include at least one sensor unit. The control device may be configured to receive or request sensor signals from at least one sensor unit and control the light from the imaging light source based on the sensor signals. To this end, the control device may adjust the image signal based on the sensor signals.

[0042] At least one sensor unit and control device can be housed in a common enclosure. This reduces the number of physical components required to retrofit the display device.

[0043] At least one sensor unit may include a position sensor. The position sensor may be configured to determine the coordinates of the display device based on a Global Navigation Satellite System (GNSS), such as GPS, GLONASS, Galileo, Beidou, etc. The sensor signal may include a position value. The position value may include geographic coordinates with longitude and latitude. The position value may include a route segment or route progress along a predetermined transportation route of the vehicle. The position value may specify a station code and / or station name. The control device may be configured to adjust the image signal based on the position value. For example, the image signal may include content matching the current location of the display device. This, for example, enables the real-time display of information about points of interest or stations. When approaching a station, such as underground, the control device may provide information to an imaging light source via the image signal, through which a three-dimensional location map of the station and its exits can be displayed.

[0044] At least one sensor unit may include a light sensor. The light sensor may be formed as a photodiode, a photometer, or an illuminance meter, and may be configured to determine the light intensity due to ambient light. The sensor signal may include a luminance value.

[0045] If the sensor signal includes a brightness value, the control device can be configured to control the light intensity of the imaging light source based on the brightness value. The control device can be configured to continuously increase and / or decrease the light intensity according to the brightness value.

[0046] At least one sensor unit may include a camera. The camera may be configured to capture a viewing area at a specific angle. The camera may be configured to capture a viewer's interaction within the viewing area or movement on or in front of the diffraction film.

[0047] At least one camera may include a viewing area comprising a diffraction film and a viewing area at a specific angle. If the system has multiple cameras, the multiple cameras may have a combined viewing area, which may include at least a viewing area illuminated by the diffraction film. One or more cameras may recognize interactions between the viewer or passenger and the information displayed on the diffraction film. In other words, the cameras may recognize gestures by the viewer in relation to the information displayed on the display device. The cameras may generate control signals based on the recognized gestures. A control device, configured to communicate with the cameras, may generate image signals based on camera signals or camera control signals, and preferably provides them to an imaging light source. The control device may also control facility-specific functions, such as opening doors and / or transmitting station requests, based on camera signals or camera control signals. By converting the viewer's gestures into image signals or control signals, interaction between the viewer or passenger and the display device and / or the public transport facility becomes possible. Existing surveillance cameras in conventional carriages can be used as cameras. Additional cameras may be provided to capture interactive gestures in the viewing area in more detail. Therefore, the interaction between the viewer and the display device of the present invention can also be modified.

[0048] The display device according to one aspect of the invention can provide alternative interaction possibilities, such as capacitive gesture control, projected capacitive touchscreen (PCAP), resistive touchscreen, or infrared touchscreen. Such a sensor system may require connecting the diffractive film to a power source, thus making it more suitable for manufacturing new window glass rather than simply retrofitting existing window glass.

[0049] Capacitive gesture control combines 2D touch functionality with 3D gesture control. This allows for the capture of touch input on the display panel and contactless input via hand movements, each converted into a control signal. Capacitive gesture control can be integrated into existing systems and is particularly suitable for systems with small to medium-sized displays.

[0050] Projected capacitive touch functionality is known in traditional smartphones and tablets. These touchscreens are rugged and durable, suitable for harsh environments, as they are protected by a glass cover.

[0051] Resistive touchscreens are configured to respond to pressure. They can be operated with a stylus or a finger.

[0052] Infrared touchscreens can use an infrared grid for touch recognition. This allows for rapid capture of user interactions. Larger display panels can also be covered by the infrared grid.

[0053] The system may also include a central facility control device configured to generate and / or receive image signals and provide the image signals to at least one display device.

[0054] In summary, the display device of the present invention can convert window areas in passenger transport vehicles into display screens, thereby creating diverse possibilities for information communication. By updating image signals remotely and / or based on captured coordinates, information can be provided dynamically, context-sensitively, and in real time through the display device. The use of protective films and / or bulletproof glass covers can improve the robustness of the display device, thereby meeting the requirements of public transport. Attached Figure Description

[0055] The embodiments or further embodiments of the present invention, as well as the advantages of the present invention, will be described in more detail below with reference to the accompanying drawings, which only illustrate embodiments of the present invention. In the drawings, the same parts are represented by the same reference numerals. Elements drawn with dashed lines are considered optional elements. The drawings should not be considered as drawn to actual scale, and the various elements in the drawings may be presented in exaggerated or simplified forms.

[0056] Figure 1 A side view schematic diagram of an embodiment of a display device according to one aspect of the present disclosure is shown.

[0057] Figure 2 A perspective schematic diagram of one embodiment of a system according to one aspect of the present disclosure is shown.

[0058] Figure 3 A perspective schematic diagram of another embodiment of the system according to one aspect of this disclosure is shown.

[0059] Figure 4 A flowchart illustrating a display device control method according to one aspect of the present invention is shown. Detailed Implementation

[0060] Figure 1 A side view schematic diagram of an embodiment of a display device 10 according to one aspect of the present disclosure is shown.

[0061] Public passenger transport facility 60 may be or include the main body of a carriage. Display device 10 includes a diffraction film 11 and an imaging light source 12. For example... Figure 1 As shown, the diffraction film 11 can be arranged on the window area 61 of the main body of the carriage of a public passenger vehicle. Figure 1 The side view shows the corresponding details of the main body of the carriage. The display side 11a of the diffraction film 11 faces the interior of the main body of the carriage. Figure 1 The y-direction is displayed in the image.

[0062] The diffraction film 11 may include microstructures formed by laser photolithography with a predetermined wavelength or wavelength range, or exposed in the form of a volume hologram. Therefore, when illuminated with light 15 having a predetermined wavelength or from a predetermined wavelength range, the diffraction film 11 is configured to generate or display an observation region 20 at a suitable angle at a distance in the y-direction from the diffraction film 11. For this purpose, a deflected beam 16 is coupled out through the microstructure of the diffraction film 11. The observation region 20 is... Figure 1 It is represented by a star.

[0063] The shape of the observation area 20 is controlled by the imaging light source 12. The imaging light source 12 is configured to emit light corresponding to the image signal. The imaging light source 12 may be, for example, a projector. The imaging light source 12 is arranged near the plane defined by the diffraction film 11 such that light 15 is incident on the diffraction film 11 at an acute incident angle of at least 8°. Figure 1 As shown, the imaging light source can be arranged at a certain distance from the diffraction film 11 in the z and y directions.

[0064] exist Figure 1 In the diagram, the beam emitted by the imaging light source 12 is represented by a dashed line, and the beam 16 deflected from the diffraction film 11 is represented by a dotted line.

[0065] Figure 2 A perspective schematic diagram of an embodiment of a system 1 according to one aspect of the present disclosure is shown.

[0066] Public passenger transport facilities 60 may include or include the main body of the carriage. Figure 2 An interior view of window area 61 of the main body of the carriage is shown. Through window area 61, a hand can be seen from the outside of the main body of the carriage. For example, see above. Figure 1 A diffraction film 11 is arranged on the window area 61. An imaging light source 12 is arranged at a certain distance from the diffraction film 11 on the main ceiling of the carriage. The imaging light source 12 is configured to directly illuminate the diffraction film 11 with light having a predetermined wavelength or a predetermined wavelength range.

[0067] The imaging light source 12 can receive image signals from the control device 30. For this purpose, the display device may include a corresponding interface (not shown). The image signals can control the imaging light source 12.

[0068] Figure 3 A perspective schematic diagram of another embodiment of system 1 according to one aspect of this disclosure is shown.

[0069] Figure 3 The explanation is based on Figure 2 In addition, it also includes a sensor unit 14. Figure 3The sensor unit 14 can be configured as a camera. The camera may include an observation area 17 through which the observation area 20 and passenger interactions within the observation area 20 can be captured and / or interpreted. For example, a passenger's gesture can be determined by capturing hand movements combined with an image deflected into the observation area 20. Based on the determined gesture, the camera can provide sensor signals. These sensor signals may include viewer interactions. The control device 30 may also be configured to receive or request sensor signals from the camera and generate image signals and / or facility-specific control signals based on the sensor signals. As a result, the user / viewer can interactively control the display device or facility.

[0070] Figure 3 The central carriage control unit 65 was also shown, which can be connected to the display device 10 via data communication, for example, through the control unit 30.

[0071] Figure 4 A flowchart illustrating a control method for a display device 10 according to one aspect of the present invention is shown.

[0072] The method may include capturing sensor values ​​in the first step. Sensor values ​​may include, for example, position values, brightness values, and / or user interactions with the display device.

[0073] The method may include generating image signals and / or facility-specific control signals based on sensor values ​​in a second step.

[0074] The method may include controlling the imaging light source 12 in a third step. The method may also include controlling the public transportation facility 60 in a third step. This third step may be based on the image signal or control signal from the second step. That is, the image signal may prompt control of the imaging light source 12. The control signal may be a gesture control signal.

[0075] The method may include illuminating the diffraction film 11 in an optional fourth step. For this purpose, the imaging light source 12 may emit light representing an image signal. This light has a predetermined wavelength or a predetermined wavelength range.

[0076] As a direct result of the fourth step, the light from the imaging light source 12 can be deflected into the observation area 20 through the diffraction film 11. In the observation area 20 (“eyebox”), the information represented by the image signal can be presented in a way that is convenient for the viewer to record.

[0077] Alternatively, specific functions of public passenger transport facilities can be performed in the fourth step.

[0078] Reference Marker 1 System 10 Display devices 11. Diffraction film 11a Display side of diffraction film 11 12 Imaging Light Source 14 Sensor Units 15. Light emitted by imaging light source 12 16 Deflected Light 17. Observation area of ​​sensor unit 14 20 Observation Area 30 Control device 60 Public passenger transport facilities Window area of ​​facility 61 65. Central facility control unit.

Claims

1. A display device (10) for displaying images in a public passenger transport facility (60), the display device (10) comprising: A diffraction film (11) containing a volume grating is configured to display incident light with a predetermined wavelength within a viewing area (20) at a specific angle; as well as Imaging light source (12), which is used to emit light having the predetermined wavelength, The imaging light source (12) is arranged at a certain distance from the diffraction film (11) and configured to illuminate the diffraction film (11). The diffraction film has a self-adhesive side for attaching the diffraction film to the window area (61) of the public passenger transport facility (60).

2. The display device (10) according to claim 1, further comprising an interface with a control device (30) for receiving image signals, wherein, The imaging light source (12) is configured to emit light representing the image signal.

3. The display device (10) according to claim 1 or 2, wherein, The volume grating of the diffraction film (11) has a plurality of partial gratings, each of which is formed by exposure to laser light with a predetermined wavelength.

4. The display device (10) according to any one of the preceding claims, wherein, The transparency of the diffraction film (11) is at least 94%, preferably at least 96%.

5. The display device (10) according to any one of the preceding claims, wherein, The imaging light source (12) is positioned on the viewer side (11a) of the diffraction film (11) and is located outside the viewer's field of vision of the diffraction film (11).

6. The display device (10) according to any one of the preceding claims, wherein, The imaging light source (12) is configured such that the emitted light is incident on the diffraction film (11) at an incident angle of at least 8°.

7. The display device (10) according to any one of the preceding claims, wherein, The diffraction film (11) is disposed in the traffic area of ​​the facility (60) and / or the window area (61) of the facility (60).

8. The display device (10) according to any one of the preceding claims further comprises a protective film and / or an anti-reflective film disposed on the diffraction film (11), wherein, The protective film and / or antireflective film overlaps with the diffraction film (11) on at least one side, and preferably has an area larger than that of the diffraction film (11).

9. The display device (10) according to any one of the preceding claims further includes a control device (30), said control device (30) being connected to the imaging light source (12) via a communication channel and configured to generate and / or receive image signals, and to provide the image signals to the imaging light source (12) via the communication channel, wherein, The communication channel is preferably a wireless communication channel.

10. The display device (10) according to the preceding claim further includes at least one sensor unit (14). in, The control device (30) is configured to receive or request sensor signals from the at least one sensor unit (14) and control the light and / or facility-specific functions of the imaging light source (12) based on the sensor signals.

11. The display device (10) according to the preceding claim, wherein, At least one of the at least one sensor unit (14) and the control device (30) is disposed in a common housing.

12. The display device (10) according to any one of claims 10 or 11. in, The at least one sensor unit (14) includes a position sensor, and the sensor signal includes a position value; and / or Wherein, the at least one sensor unit (14) includes a light sensor, and the sensor signal includes a brightness value; and / or The at least one sensor unit (14) includes a camera, and the sensor signals include viewer interaction, particularly gesture control.

13. In the display device (10) according to the preceding claim, if the sensor signal includes a brightness value, the control device (30) is configured to control the light intensity of the imaging light source (12) according to the brightness value, in particular to continuously increase and / or decrease the light intensity according to the brightness value.

14. A system (1), comprising: Public passenger transport facilities (60); as well as At least one display device (10) according to any one of the preceding claims, disposed within or on the facility (60), The imaging light source (12) is connected to the power supply infrastructure of the facility (60).

15. The system (1) according to the preceding claim further includes a central facility control device (65) configured to generate and / or receive image signals and provide the image signals to the at least one display device (10).

Images