Waveguide, curved sheet comprising such a waveguide and display device comprising such a waveguide

Abstract

The invention provides a waveguide having a coupling-in region (4) and a coupling-out region (5) spaced apart therefrom, wherein the coupling-in region (4) couples at least a portion of the radiation incident thereon into the waveguide in such a way that the coupled-in portion propagates as a coupled-in beam in the waveguide (1) by way of reflection as far as the coupling-out region (5), which deflects at least a portion of the coupled-in beam in such a way that the deflected portion emerges from the waveguide (1), wherein the waveguide (1) has a plurality of transparent segments (91 – 95) which extend in a straight line and in which the coupled-in beam propagates by way of reflections, wherein each segment (91 – 95) has a planar segment front side (101 – 105) and a planar segment rear side (111 – 115) which are parallel to one another, wherein the segment front sides (101 – 105) of directly adjacent segments (91, 92; 92, 93; 93, 94; 94, 95) enclose an angle (Ω1, Ω2, Ω3, Ω4) not equal to 180° in order in this way to reproduce a curved profile of an imaginary front side (14), which curved profile is specified from the coupling-in to the coupling-out region (4, 5), wherein, of two directly adjacent segments, at least one segment has a compensation hologram (121 – 124, 132 – 135; 16, 17) onto which the coupled-in beam is incident, wherein the compensation hologram (121 – 124, 132 – 135; 16, 17) causes the coupled-in beam to propagate in the two directly adjacent segments at the same reflection angle (α) in the case of a plurality of reflections.

Description

[0001] Waveguide, curved disk with such a waveguide, and display device with such a waveguide

[0002] The present invention relates to a waveguide, a transparent curved disk with such a waveguide, and a display device with such a waveguide.

[0003] Waveguides can be used for display devices and often have an input area and a separate output area, whereby the light to be guided is coupled into the waveguide via the input area and guided to the output area by means of reflection and coupled out again via the output area.

[0004] Such waveguides can be integrated into transparent disks, for example. If the disks are curved and thin, the waveguides are typically formed in the same shape, with a curved front and back surface. However, since reflection to guide the light within the waveguide occurs at these curved surfaces, this unfortunately causes the beam path to diverge. This results in aberrations that cause wavefront errors dependent on the curvature and propagation distance. If the waveguide is part of an imaging system, this reduces image quality. If the waveguide carries an image hologram, it adversely affects the quality of the hologram reconstruction. Furthermore, varying reflection angles lead to incomplete imaging of the field of view.

[0005] Based on this, the object of the invention is therefore to provide an improved waveguide. Furthermore, a transparent curved disk with such a waveguide and a display device with such a waveguide are to be provided.

[0006] The invention is defined in the independent claims. Advantageous embodiments are specified in the dependent claims.

[0007] The waveguide according to the invention can have an input region and a spaced-apart output region, wherein the input region couples at least a portion of incident radiation into the waveguide such that the coupled portion propagates as a coupled beam within the waveguide by reflection to the output region, which deflects at least a portion of the coupled beam such that the deflected portion exits the waveguide. The waveguide can have several straight-extending transparent segments in which the coupled beam propagates by reflection, each segment having a flat front and a flat back surface that are parallel to each other.

[0008] The front faces of directly adjacent segments can form an angle other than 180° with each other, thus replicating a curved path of an imaginary front face from the coupling-in to the coupling-out region. Of two directly adjacent segments, at least one can have a compensation hologram onto which the coupled beam of light strikes, the compensation hologram causing the coupled beam of light to propagate with the same reflection angle in the two directly adjacent segments for a majority of reflections.

[0009] Thus, according to the invention, the predetermined curved profile of the conceptual front face can be replaced by the flat segment front faces in a segmented manner, so that no varying reflection angles occur. Individual deviating reflection angles, which may be unavoidable due to the segmented design of the waveguide, are compensated by the compensation hologram (or by several compensation holograms), so that the overall beam path does not diverge and thus excellent beam guidance can be provided. At the same time, the desired curved shape of the waveguide can be realized, so that the waveguide can, for example, be part of a curved thin disk and / or be integrated into it. The curved disk can, for example, have a cylindrical curvature.The disk and / or the waveguide can have the specified curved profile in a first plane and extend straight (without curvature) perpendicular to it.

[0010] In particular, the flat segment front faces can run perpendicular to the first plane, so that the specified curved profile is present in the first plane.

[0011] The compensation hologram of the at least one segment can be formed on the flat front or back surface of the segment. In particular, each compensation hologram can be formed on the flat front or back surface of the corresponding segment. In the waveguide, a first segment and a directly adjacent second segment can be formed as separate segments and arranged such that (preferably) only a portion of the flat front surface of one of the two separate segments faces a portion of the flat back surface of the other of the two separate segments.

[0012] At least two of the straight, transparent segments can be identical. This can reduce the manufacturing costs of the waveguide.

[0013] Reflections guiding the coupled beam can occur, in particular, at the front and rear faces of the segments. At least one of these reflections can be a total internal reflection or a reflection at a reflective or partially reflective layer or coating. Several or all reflections can also be total internal reflections. Furthermore, it is possible that a reflective coating is applied to one or more segment faces and / or one or more segment rear faces, at which at least one (or several or all) of the reflections occur.

[0014] The coupling region can be configured to deflect the portion of the radiation upon coupling, which then propagates as a coupled beam within the waveguide. In particular, the coupling region can be reflective, refractive, and / or diffractive. Preferably, the coupling region can feature a hologram. The coupling region can be located on the flat front or back surface of the segment.

[0015] The waveguide can be designed such that a first and a directly adjacent second segment are formed as separate segments, with the first segment having an outcoupling hologram that couples out the coupled beam of light in such a way that it hits the second segment and is coupled into it.

[0016] The second segment may have a coupling hologram that couples the beam of light coming from the first segment into the second segment. It is also possible that the second segment does not have a coupling hologram. In this case, the beam of light coming from the first segment can enter the second segment, for example, via the front or back of the segment.

[0017] The output hologram and / or the input hologram can be considered

[0018] Compensation holograms are used. Additionally or alternatively, the output hologram can be formed on the flat front or back of the segment, and the input hologram can be formed on the flat front or back of the segment.

[0019] In particular, the waveguide can have three or more separate segments, each designed in the same way as the first and second segments.

[0020] Furthermore, it is possible that at least two directly adjacent segments of the waveguides are formed as a single piece. In this case, the coupled beam of radiation does not need to exit via a front or back surface at the transition between the two directly adjacent segments and re-enter the next segment via the front and back surfaces, but can propagate the coupled beam of radiation exclusively within the material of the first and second segments.

[0021] The waveguide according to the invention can comprise a combination of separate segments and segments formed in one piece. However, it is also possible that the waveguide comprises only separate segments or only segments joined together in one piece.

[0022] The output area can display a hologram or an image hologram.

[0023] In particular, the output coupling area can be configured as a holographic diffuser, so that image information contained in the coupled beam is perceptible to a viewer as an image by means of the diffuser function. The image information can, for example, be perceived in a plane of the output coupling area. Thus, different images can be displayed (depending on the information in the coupled beam).

[0024] Furthermore, the output coupling area can be configured as an image hologram, with the image information embedded (and unchangeable) in the image hologram. When the coupled beam of light strikes the image hologram, the embedded image is reconstructed in a known manner and thus becomes perceptible to an observer. The image hologram can, in particular, be configured as an image-plane hologram, in which the reconstructed image is perceptible, for example, as a (essentially planar) image in the waveguide or as a (essentially planar) image in a film or coating in which the hologram is formed. The image hologram can be configured to have several embedded images designed for different wavelengths, so that, depending on the selected wavelength of the coupled radiation, one of the images of the image hologram can be selectively reconstructed.The waveguide segments can be made of plastic and / or glass.

[0025] All described holograms can be designed as reflective holograms and / or as transmissive holograms. Furthermore, the holograms can be designed, for example, as volume holograms or surface holograms. At least one, several, or all of the holograms can be designed, for example, in a film or coating that may be part of the corresponding segment or connected to it.

[0026] The waveguide according to the invention can be configured to perform an infinity-to-infinity mapping. However, it is also possible for it to perform a finite-to-infinity mapping, an infinity-to-finite mapping, or a finite-to-finite mapping.

[0027] Furthermore, a transparent curved disc with a waveguide according to the invention (including all further developments) is provided. The transparent curved disc can, in particular, have a cylindrical curvature or any other arbitrary curvature. It can, for example, be a disc in a vehicle on land, water, and / or air. In particular, it can be windows or doors (or parts thereof) of the passenger compartments of trains (preferably ICE trains). It can also be other discs, such as shop windows, glass panes of household appliances, furniture, or refrigerated display cases. It can also be curved visors on helmets or protective windscreens of motorcycles or the like.

[0028] The waveguide according to the invention can, for example, be used in or be part of a HUD (Head-Up Display) and / or an HMD (Head-Mounted Display).

[0029] A Head-Up Display (HUD) projects information (e.g., speed, navigation) directly into the driver's field of vision on the windshield or another transparent surface. This allows the driver to read the information without taking their eyes off the road. HUDs can also be used on trucks, motorcycles, boats, airplanes, and other vehicles for land, water, and / or air. A Head-Mounted Display (HMD) is a head-mounted display (e.g., in the form of glasses or as part of a helmet) that projects information directly in front of the wearer's eyes. It can, for example, cover the entire field of vision, a portion of it, or overlay the information onto the surrounding environment.Furthermore, a display device is provided comprising a waveguide according to the invention (including all further developments) and a radiation source that emits the radiation incident on the coupling area. The display device can be configured as a HUD or as an HMD, or can be part of a HUD or an HMD.

[0030] If the output coupling area displays an image hologram, the radiation source can be, for example, an LED and / or laser. If the output coupling area is designed as a diffuser, the radiation source can be, for example, an image module that generates an image and directs it as a beam of light onto the input coupling area.

[0031] The image module can include an image source (preferably planar) and a control unit (e.g., with a processor and memory) for image generation. The image source can be, for example, an LCD module, an LCoS module, an OLED module, a pLED module, or a tilting mirror matrix. Furthermore, the image source can have a plurality of pixels, arranged, for example, in columns and rows. Additionally, the image source can be self-illuminating and / or non-self-illuminating.

[0032] Furthermore, an imaging device is provided with a waveguide according to the invention (including all further developments) and a detector on which the deflected part of the coupled beam exiting the waveguide hits.

[0033] The detector can be connected to the flat front or back surface of one of the segments. In particular, a direct connection is possible. The detector can be a digital image sensor (e.g., a CCD sensor or a CMOS sensor), a detector array, or, for example, a solar cell.

[0034] Furthermore, the imaging device can be configured such that at least one optical imaging element is arranged in the area between the detector and the flat front or back surface of the segment. This at least one optical imaging element can be, for example, a lens, a refractive lens, or a refractive camera lens. It is also possible for the area between the detector and the flat front or back surface of the segment to be free of imaging optical elements. In other words, the deflected portion of the coupled beam exiting the waveguide strikes the detector without having passed through any further optical imaging elements. In this case, it is advantageous if the output coupling area has an optical imaging property in addition to the deflection. The imaging device according to the invention can be configured as a camera (e.g., a digital camera or video camera).

[0035] In the display device, the waveguide can be part of a curved disk. The curved disk is preferably transparent.

[0036] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations given, but also in other combinations or on their own, without leaving the scope of the present invention.

[0037] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying drawings, which also disclose essential features of the invention. These exemplary embodiments serve only for illustration and are not to be interpreted as limiting. For example, a description of an exemplary embodiment with a plurality of elements or components is not to be interpreted as meaning that all of these elements or components are necessary for implementation. Rather, other exemplary embodiments may also contain alternative elements and components, fewer elements or components, or additional elements or components. Elements or components of different exemplary embodiments may be combined with one another unless otherwise specified. Modifications and variations described for one of the exemplary embodiments may also be applicable to other exemplary embodiments.To avoid repetition, identical or corresponding elements in different figures are designated with the same reference symbols and are not explained multiple times. The figures show:

[0038] Fig. 1 a schematic representation of a holographic display device 2 with a waveguide 1 according to the invention;

[0039] Fig. 2 is a schematic representation to explain the segmented reproduction of the curved path of an imaginary front face 14 by the segments 9i - 9s of the waveguide 1 of Fig. 1;

[0040] Fig. 3 a schematic representation of a known waveguide 1 ' with curved front and back sides 10', 11 ';

[0041] Fig. 4 is a schematic representation of a modification of the holographic display device 2 and the waveguide 1 of Fig. 1; Fig. 5 is a schematic representation of another holographic display device 2 with a different embodiment of a waveguide 1 according to the invention;

[0042] Fig. 6 shows a modification of the holographic display device 2 and the waveguide 1 from Fig. 5, and

[0043] Fig. 7 shows a schematic representation of a holographic imaging device 20 with a waveguide 1 according to the invention as shown in Fig. 1.

[0044] In the embodiment of a waveguide 1 according to the invention shown in Figure 1, this part is a holographic display device 2.

[0045] The holographic display device 2 comprises, in addition to the waveguide 1, an image generation module 3, which generates an image that is coupled into the waveguide 1 via an input coupling area 4 of the waveguide 1, guided in the waveguide 1 (as will be described in detail below) up to an output coupling area 5 spaced apart from the input coupling area 4 and is coupled out by means of the output coupling area 5, so that a user can perceive the image with his eye A.

[0046] To generate the image, the image generation module 3 comprises an image sensor 6, which is controlled by a control unit 7 containing a processor P and a memory M. The image thus generated is then fed to the coupling area 4 via an image optic 8 (which may, for example, have one or more lenses). The image optic 8 is optional and can also be omitted.

[0047] The image source 6 can be, for example, a planar image source 6, such as an LCD module, an LCoS module, an OLED module, a pLED module, or a tilting mirror matrix. The image source 6 can have a plurality of pixels, which can be arranged, for example, in rows and columns. The image source can be, for example, self-illuminating or non-self-illuminating.

[0048] In the embodiment shown in Fig. 1, the waveguide 1 comprises five straight, transparent segments 9i-9s. Each segment 9i-9s has a flat front face 10i-10s and a flat back face 111-115, which are aligned parallel to each other. The front faces 10i-10s and the back faces 111-115 extend perpendicular to the xy-plane and the plane of the drawing, respectively. The segments 9i-9s each have the form of a plane-parallel plate. The first segment 9i has the coupling area 4 on its back face 111, which is designed here as a hologram. However, the coupling area 4 can also be designed in any other way. For example, it can be designed as a prismatic element.Furthermore, it is possible to design the image generation module 3 such that the generated image enters the first segment 9i at the desired angle to the beam path, so that in this case the area of ​​the segment back 1 1 1, through which the generated image enters the first segment 9i, is the coupling area 4.

[0049] As schematically illustrated in Figure 1, in the embodiment described here, the coupling area 4 deflects the coupled image (represented by two light rays from a pixel – one with a solid line and the other with a dashed line – representing the generated and coupled image), so that the coupled image is then guided by total internal reflection at the front face 10i and the rear face 111 of the segment to an output hologram 12i of the first segment 9i. The output hologram 12i is formed on the front face 10i of the segment.

[0050] The segments 9i - 9s are arranged such that the segment front faces 10i - 10s of directly adjacent segments 9i - 9s enclose an angle Di , Q2, Q3 and O4 of non-180° with each other, so that the segment front faces 101 - 10s follow a curved path of an imaginary front face 14 (in the xy-plane), as shown schematically in Figure 2.

[0051] Segments 92-94, the second through fourth, each have an input hologram 132-134 and an output hologram 122-124, as shown in Figure 1. The fifth segment has an input hologram 13s. The input and output holograms 132-13s and 122-124 are each located either on the front face 101-10s or the rear face 111-115 of the respective segment 9i-9s. Furthermore, it is clearly visible in Figure 1 that the front face 101-10s or the rear face 111-115 of directly adjacent segments 9i-9s partially overlap (preferably in the area of ​​the corresponding input and output holograms 132-13s and 122-124).

[0052] As schematically shown in Figure 1, the coupled image is coupled out of the corresponding segment 9i-94 via the respective output hologram 12i-124 and coupled back into the corresponding segment 92-9s via the respective input hologram 132-13s of the directly adjacent segment 92-9s, whereby in each segment 9i-9s the coupled image is guided by total internal reflection at the segment front 10i-10s and the segment back 111-115. The light then strikes the output coupling area 5 in the fifth segment 9s, which causes output coupling via the segment front 105.

[0053] The outcoupling hologram 12i of the first segment 9i and the incoupling hologram 132 of the second segment 92 are designed such that the coupled image in the second segment 92 is guided with the same reflection angle α (to the normal, which is schematically drawn, of the surface at the point of incidence) during total internal reflection at the segment front I O2 and the segment back 1 12 as in the first segment 9i .

[0054] The same applies to the combination of the second output hologram 122 and the third input hologram 13s, to the combination of the third output hologram 12s and the fourth input hologram 134, and to the combination of the fourth output hologram 124 and the fifth input hologram 13s.

[0055] Thus, the coupled image is guided with the same reflection angle α in each segment 9i-9s, so that the beam path does not diverge in segments 9i-9s and no unwanted aberrations are introduced by the guidance in segments 9i-9s. More precisely, the light rays L1, L2 from each field point can have a different guidance angle (i.e., when a field of view is propagated through the waveguide), but this angle does not change in the individual segments 9i-9s.

[0056] Figure 3 schematically shows the beam path into a curved waveguide 1', whose front face 10' has the curvature of the imaginary front face 14 according to Figure 2. Due to the curvature of the front face 10' and the back face 11' of the waveguide 1', the reflection angle changes with each reflection. If the reflection angle α is present at the first reflection, the reflection angles β1, βs, and βs, respectively, occur at subsequent reflections, where β1 and β2, βs and β4, and βs and β differ. This leads to the beam path diverging and wavefront errors are caused, depending on the curvature of the front and back faces and the propagation distance. Incomplete imaging of the field of view can also occur.

[0057] The segmented design of the waveguide 1 according to the invention avoids the problems described, since the same reflection angle α is always present during propagation of the coupled image in the waveguide (for each field point). A curved waveguide 1 with excellent optical properties can thus be provided. Since the out-coupling and in-coupling holograms 12i-124, 132-13s serve to ensure that the reflection angles α are the same in adjacent segments 9i-94, these holograms can also be referred to as compensation holograms.

[0058] In a further development not shown, it is possible to omit the coupling hologram 132-13s for at least one of the segments 92-9s. In this case, only the corresponding output coupling hologram 12i-124 needs to be designed such that, after entering the corresponding segment, the coupled image propagates in such a way that the desired reflection angle α is present.

[0059] Segments 9i - 9s can be made of glass or plastic.

[0060] The output area 5 can be configured as a hologram. In particular, it can be configured as a holographic diffuser, so that a user can perceive the coupled-in image, which strikes the output area 5, as an image in the plane of the output area 5. The output area 5 can therefore also be described as an image hologram, whereby, when configured as a holographic diffuser, the image information is provided by the coupled-in image (or the correspondingly guided light rays).

[0061] However, it is also possible to design the output coupling area as a hologram in which the desired image information is embedded within the hologram. In this case, it is only necessary to couple light from a suitable light source 15 into the waveguide 1 via the input coupling area 4, as schematically shown in Figure 4. The coupled light is guided via segments 9i–9s to the output coupling area 5 and directed onto it in the same manner as described in conjunction with Figure 1, so that the image information embedded in the output coupling area 5 is reconstructed by means of the incident light or beam, making the reconstructed image perceptible to a viewer. The output coupling area 5 can, in particular, be designed as an image-plane hologram in which the reconstructed image is perceptible as a (essentially planar) image.

[0062] A laser and / or an LED can be used as light source 15, for example.

[0063] Figure 5 shows a modification of the waveguide 1 according to Figure 1. In the embodiment shown in Figure 5, the waveguide 1 has three straight segments 9i - 9s. The waveguide 1 in Figure 5 is monolithic. However, due to the three segments 9i - 9s, the reflection angle α would change, as is the case, for example, for the dashed line beam at the first reflection in the second segment 92. Here, the reflection angle is θ. To ensure that a reflection angle of α is maintained throughout the propagation process, the second segment 92 has a first compensation hologram 16. Similarly, the third segment 9s has a second compensation hologram 17. This ensures that the same reflection angle α is maintained in each segment throughout the propagation process.

[0064] In embodiment 5, any coupling losses that may occur between the separate segments 9i - 9s according to embodiments 1 and 4 can be advantageously avoided.

[0065] In embodiment 5, the curved waveguide can be referred to as a segmented monolithic waveguide 1. With such a waveguide 1, the desired coupling, guiding, and decoupling of the generated image is possible.

[0066] Figure 6 shows a modification of the embodiment shown in Figure 5. In this case, as in the embodiment shown in Figure 4, the output coupling area 5 is designed as an image hologram, and a light source 15 is provided to supply the light with which the image in the output coupling area 5 is then reconstructed when the light coupled into and guided in the curved monolithic waveguide 1 strikes the output coupling area 5.

[0067] Figure 7 shows an embodiment of an imaging device 20 with a waveguide 1 as shown in Figure 1. The imaging device can image an object 21 (in Figure 7, a star is shown as an example) onto a detector 22. Radiation coming from the object 21 can be collimated by means of a first optic 23 and directed onto the coupling area 4, so that the coupled radiation is guided in the waveguide 1 as described to the output coupling area 5 and coupled out from there. The coupled-out radiation can then be directed or focused onto the detector 22 by means of a second optic 24. The first and / or second optic 23, 24 are optional and can also be omitted. In the embodiment shown in Figure 7, the imaging device can also be referred to as a camera.Furthermore, the imaging device 20 can also have the waveguide 1 of the other embodiments (in particular according to Figures 5 and 6).

Claims

Patent claims 1. Waveguide with an input region (4) and an output region (5) spaced apart therefrom, wherein the input region (4) couples at least a part of incident radiation into the waveguide in such a way that the coupled part propagates as an input beam in the waveguide (1) by reflection to the output region (5), which deflects at least a part of the coupled beam in such a way that the deflected part exits the waveguide (1), wherein the waveguide (1) has several straight-extending transparent segments (9i - 9s) in which the coupled beam propagates by reflection, wherein each segment (9i - 9s) has a planar segment front (10i - 10s) and a planar segment back (111 - 115) which are parallel to each other, wherein the segment fronts (101 - 105) of directly adjacent segments (9i, 92; 92, 9s; 9s, 94;94, 9s) enclose an angle (Qi , Q2, Q3, Q4) of non-180° with each other in order to reproduce a curved path of an imaginary front face (14) from the coupling-in to the coupling-out area (4, 5), wherein at least one of two directly adjacent segments has a compensation hologram (12i - 124, 132 - 13s; 16, 17) onto which the coupled beam of light strikes, wherein the compensation hologram (12i - 124, 132 - 13s; 16, 17) causes the coupled beam of light to propagate in the two directly adjacent segments with the same reflection angle (a) for a majority of the reflections.

2. Waveguide according to claim 1, wherein the compensation hologram (12i - 124, 132 - 13s; 16, 17) of the at least one segment (9i, 92; 92, 9s; 9s, 94; 94, 9s) is formed on the planar segment front (101 - s) or the planar segment back (1 11 - 1 15).

3. Waveguide according to claim 1 or 2, wherein a first and a directly adjacent second segment (9i , 92) are designed as separate segments and are arranged such that a part of the planar segment front (10i) of one of the two separate segments faces a part of the planar segment back (1 12) of the other of the two separate segments.

4. Waveguide according to one of the above claims, wherein at least two of the straight-extending transparent segments (9i - 9s) are identical.

5. Waveguide according to one of the above claims, wherein the planar segment front faces (10i - 10s) extend perpendicular to a first plane, such that the specified curved path is present in the first plane.

6. Waveguide according to one of the above claims, wherein the coupling area (4) deflects part of the radiation during coupling.

7. Waveguide according to one of the above claims, wherein the coupling area (4) has a hologram.

8. Waveguide according to one of the above claims, wherein at least one of the reflections in the waveguide is an internal total reflection.

9. Waveguide according to one of the above claims, wherein a first and a directly adjacent second segment (9i , 92) are designed as separate segments, the first segment having an outcoupling hologram (12i) which couples out the coupled beam of light such that it hits the second segment (92) and is coupled into it.

10. Waveguide according to claim 9, wherein the second segment (92) has a coupling hologram (13s) that couples the beam of rays coming from the first segment into the second segment.

11. Waveguide according to claim 9 or 10, wherein the output coupling hologram (12i) and / or the input coupling hologram (13s) serves as a compensation hologram.

12. Waveguide according to one of the above claims, wherein at least two directly adjacent segments (9i - 9s) are formed in one piece.

13. Waveguide according to one of the above claims, wherein the output coupling area comprises a hologram or an image hologram.

14. Transparent curved disk with a waveguide according to any one of the above claims.

15. Display device with a waveguide according to any one of claims 1 to 13 and a Radiation source (3; 15) that emits the radiation striking the coupling area (4).

16. Imaging device with waveguide according to one of claims 1 to 13 and a detector (22) on which the deflected part of the coupled beam exiting the waveguide (1) meets.

17. Device according to claim 15 or 16, wherein the waveguide (1) is part of a curved disk.

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