Spectacle lens for a display device which can be placed on the head of a user and which generates an image, display device comprising such a spectacle lens, and method for producing such a spectacle lens

Abstract

The invention relates to a spectacle lens for a display device (1) which can be placed on the head of a user and which generates an image, said spectacle lens (3) having a front face (23), a rear face (11), an inlet section (12), a deflecting section (18) at a distance to the inlet section (12), and a light-guiding channel (21) which guides light bundles (L1) of the generated image in the spectacle lens (3), said light bundles being coupled into the spectacle lens (3) via the inlet section (12), and to a deflecting section (18) by means of at least one reflection process, said light bundles being deflected by the deflecting section in order to exit the spectacle lens (3) via the rear face (11). The light-guiding channel (21) has a main part (13) and a first channel boundary layer (16), wherein the main part (13) comprises a first boundary surfaces (14) and a second boundary surface (15), one of which faces away from the front face (23) and the other of which faces away from the rear face (11), and the first channel boundary layer (16) is applied directly onto the first boundary surface (14) and is designed as an angle-based reflective layer which only reflects the light bundles (L1) if the angle of incidence of the light bundles is greater than a specified first threshold angle. A first colored layer is applied onto the first channel boundary layer (16), said colored layer being designed as an adhesive layer or as a coating layer.

Description

[0001] Spectacle lens for a display device that can be placed on the head of a user and generates an image, display device with such a spectacle lens and method for producing such a spectacle lens

[0002] The present invention relates to a spectacle lens having the features of the preamble of claim 1, a display device having such a spectacle lens and a method for producing such a spectacle lens.

[0003] A spectacle lens of the type mentioned above is known from WO 2015 / 158833 A1. Such lenses can be used, for example, in a display device that can be placed on a user's head and generates an image, to provide so-called smart glasses. Such smart glasses are intended, for example, to have a sun protection function or to be designed as colored smart glasses for fashion reasons.

[0004] According to DE 10 2016 105 060 B3, this can be achieved in spectacle lenses for a display device that can be placed on a user's head and generates an image by bonding a film to the base body using an adhesive layer. The film has an absorbing, reflecting, or polarizing coating or a coloring to reduce transmission through the spectacle lens. The refractive index of the adhesive layer in the spectacle lens of DE 10 2016 105 060 B3 is lower than the refractive index of the base body, so that the light of the generated image is guided in the base body by total internal reflection. According to the teaching of DE 10 2016 105 060 B3, the interference layer system for light guidance known from WO 2015 / 158833 A1 is to be dispensed with.

[0005] Although the light of the imaging beam path or the generated image in the case of the spectacle lens of the type mentioned above travels a significantly longer path through the base body than the incident ambient light or the incident sunlight, the desired sun protection function or the desired colored data glasses can be provided, since this is achieved according to the teaching of DE 102016 105 060 B3 by the film glued to the base body.

[0006] A fully tinted material—as is common in standard sunglasses—would not be suitable for the lens mentioned above, because the light rays creating the virtual image would be significantly reduced in brightness than the incoming sunlight. The same applies to many other design approaches in which the light creating the virtual image is guided through a light guide / waveguide.

[0007] However, this technical solution of DE 102016 105 060 B3 requires a film specifically colored in this color variant for each color variant.

[0008] Such films can be cost-effectively manufactured from colored granulate material, but this requires certain minimum quantities, making a differentiated color palette uneconomical. Combining differently colored films is conceivable, but results in thicker glass, which is undesirable for aesthetic reasons. Alternatively, clear or pre-colored films can be recolored before or after they are applied to the base glass, but this is complex and difficult to reproduce.

[0009] Based on this, the object of the invention is to provide a spectacle lens of the type mentioned above that can be produced cost-effectively and has a desired sun protection function or a design as a colored spectacle lens that is desirable for fashion reasons. Furthermore, a display device with such a spectacle lens and a method for producing such a spectacle lens are to be provided.

[0010] The invention is defined in independent claims 1, 11 and 12. Advantageous further developments are specified in the dependent claims.

[0011] The spectacle lens according to the invention for a display device that can be placed on a user's head and generates an image comprises a front side and a back side, an entrance section, a deflection section spaced from the entrance section, and a light guide channel. The light guide channel guides light beams of the generated image, which are coupled into the spectacle lens via the entrance section of the spectacle lens, through at least one reflection in the spectacle lens to the deflection section, from which they are deflected to exit the spectacle lens via the back side.

[0012] The light guide channel has a base body and a first channel boundary layer, wherein the base body comprises a first boundary surface and a second boundary surface, one of which faces away from the front side and the other away from the back side. The first channel boundary layer is applied (preferably directly) to the first boundary surface and is designed as an angle-dependent reflection layer that only reflects the light beams if their angle of incidence is greater than a predetermined first critical angle. According to the invention, a first colored layer, which is designed as an adhesive layer or a lacquer layer, is applied (preferably directly) to the first channel boundary layer.

[0013] Thus, the colored adhesive or lacquer layer can be used to achieve the desired colored design of the lens and / or the desired sun protection function.

[0014] The colored adhesive or coating layer is preferably monochrome. A dye and / or pigments, for example, can be used as a colorant to form the colored adhesive or coating layer. Thus, the first adhesive or coating layer is provided with a colorant.

[0015] Dyes are chemical compounds that have the property of coloring other materials and are soluble in their application medium (here, the adhesive or paint layer). Pigments, on the other hand, are insoluble in their application medium (here, the adhesive or paint layer).

[0016] At least one further layer can be applied to the adhesive or lacquer layer (or the first colored layer). The at least one further layer can provide a polarization-dependent filter effect and can be formed as a colored layer and / or as a phototropic layer. The at least one further layer can be formed as a film.

[0017] The first colored layer can be formed as a viscous or solid intermediate layer, as a viscous or solid layer and / or as an adhesive layer.

[0018] The tinting of the first colored layer is simple and can be customized to individual lenses. Tinting is especially easy when the first colored layer is designed as an adhesive layer.

[0019] In all cases mentioned, the term “colorant” also includes photochromic colorants.

[0020] In combination with, for example, a clear polarizing film as at least one additional layer, sunglasses with a polarizing effect can be produced. If this polarizing film is pre-colored, the color and intensity of the tint of the lens can be further varied by the colored formation of the first channel boundary layer. The first channel boundary layer can, for example, be designed in such a way that it is suitable for angles of incidence in the

[0021] Transmissive in the range from 0° to a predetermined second critical angle of less than 90°. The second critical angle is less than or equal to the first critical angle.

[0022] These transmission / reflection properties are preferential for radiation in the visible wavelength range.

[0023] The first critical angle can be, for example, in the range of 45°-65°, preferably in the range of 50°-60°. The second critical angle can be, for example, in the range of 30°-60°, preferably in the range of 35°-45°.

[0024] The first channel boundary layer can comprise an interference layer system or be formed as an interference layer system. The interference layer system can be formed from at least two different materials with different refractive indices. In particular, the interference layer system can comprise two, three, four, or five different materials. The refractive indices of the materials can be in the range from 1.4 to 2.5 at a wavelength of 546 nm.

[0025] The light guide channel can further comprise a second channel boundary layer, which is applied (preferably directly) to the second interface and is designed as an angle-dependent reflection layer that only reflects the light beams of the generated image if their angle of incidence is greater than a predetermined third critical angle. The second channel boundary layer can be designed and developed in the same way as the first channel boundary layer. In particular, the second channel boundary layer can comprise an interference layer system or be designed as an interference layer system.

[0026] The second channel boundary layer can be designed such that it only reflects light beams if their angle of incidence relative to the normal to the surface of a surface element at which the reflection is to take place is greater than a predetermined third critical angle. The second channel boundary layer can further be designed such that it is transmissive for angles of incidence in the range from 0° to a predetermined fourth critical angle of less than 90°. The fourth critical angle is less than or equal to the third critical angle. The first and third critical angles can be the same or different. Furthermore, the second and fourth critical angles can be the same or different. These transmission / reflection properties are preferably present for radiation in the visible wavelength range. A second colored layer, which is designed as an adhesive layer or a lacquer layer, can be applied to the second channel boundary layer.The second colored layer can be formed and developed in the same way as the first colored layer.

[0027] The base body can be formed from a first material with a first refractive index. Furthermore, the light guide channel can have a second channel boundary layer applied directly to the second interface, wherein the second channel boundary layer is formed from a second material with a second refractive index. The second refractive index is smaller than the first refractive index, so that reflections of the light beams at the boundary between the second channel boundary layer and the second interface are total reflections.

[0028] The second channel boundary layer can be formed as a colored layer and can in particular be formed and / or further developed in the same way as the first colored layer.

[0029] The second channel boundary layer can be formed as an adhesive layer or as a lacquer layer.

[0030] With the second channel boundary layer as a colored layer or with the second colored layer, a further degree of freedom is available for adjusting, for example, the color of the spectacle lens and / or the intensity of the tint of the spectacle lens. In particular, the second channel boundary layer or a layer formed on the second channel boundary layer can be designed, for example, as a second adhesive layer, with which a further layer, a further film, or a corrective lens can be permanently bonded to the base body. The corrective lens can be, for example, a lens for correcting a user's vision impairment.

[0031] The base body can be made of glass or plastic. The same applies, for example, to the corrective lens and the described films.

[0032] The spectacle lens can have an exit section on the rear side through which the deflected light beams exit the lens. Furthermore, the deflection section can redirect the light beams guided to it toward the exit section in such a way that they exit the lens through the exit section and are thus decoupled from the lens.

[0033] The deflection section and the exit section can be spatially separate sections. However, it is also possible for the deflection section and the exit section to coincide spatially, e.g., if the deflection section is designed as a surface grating. Furthermore, a display device is provided with a holding device (e.g., in the manner of glasses) that can be placed on the head of a user, an image generation module that is attached to the holding device and generates an image, and a spectacle lens according to the invention that is attached to the holding device. The generated image can be coupled into the spectacle lens via the entry section, guided in the spectacle lens by at least one reflection to the deflection section, and deflected at the first deflection section to exit the spectacle lens via the back, so that the user can perceive it as a virtual image when the holding device is placed on the head.

[0034] Furthermore, a method for producing a spectacle lens according to the invention is provided, in which a base body which has a first interface, a second interface and a deflection section is provided, a first channel interface layer is applied (preferably directly) to the first interface, wherein the first channel interface layer is designed as an angle-dependent reflection layer and only reflects a light beam if its angle of incidence is greater than a predetermined first critical angle, and wherein in the method a first colored layer which is designed as an adhesive layer or as a lacquer layer is applied to the first channel interface layer.

[0035] The first colored layer is usually colored with a colorant before it is applied to the base body and / or to the (preformed) additional layer (e.g., cover film), and before the two parts are joined. A variant, however, is that the additional layer (e.g., cover film) remains on the first colored layer only during the curing process of the first colored layer and is then removed again once the first colored layer has reached the desired strength. The additional layer (e.g., cover film) serves as a mold for applying the intermediate layer. Coloring can then also be done afterward.

[0036] Furthermore, it is possible that this mold for the first colored layer is a permanent or reusable mold made of, for example, plastic, glass, ceramic and / or metal.

[0037] If the first colored layer is applied in a wet-chemical process, the economical production of small batch sizes is also possible. The colored material system that forms the first colored layer can be applied using a spin coating process or as a spray or dip coating. Coloring the wet-chemical layer after it has been applied to the base body and before the application of the subsequent layer (e.g. cover film) is also possible. The first colored layer applied in this way (e.g. low-refractive index) and colored can have hardness levels such as those commonly used for hard coatings in the production of plastic ophthalmic lenses, so that this first colored layer can also take on the function of conventional hard coatings. In particular, the first colored layer can be designed as a lacquer layer or as a hard lacquer layer. The first colored layer can therefore, for example,form a finishing layer or the interface for anti-reflective coatings, mirror and / or clean coatings.

[0038] In the first spectacle lens, the deflecting section can have a single reflective deflecting element or several reflective deflecting elements arranged next to one another. With several reflective deflecting elements arranged next to one another, a desired deflecting function and, if appropriate, a certain imaging function of the deflecting section can be realized, for example, in a Fresnel-like manner (this can of course also be realized with a single reflective deflecting element). The reflective deflecting elements can be reflective surface pieces, which can also be referred to as reflective facets. The reflective surface pieces can each be flat. However, it is also possible for the reflective surface pieces themselves to be curved (for example, spherically or aspherically curved or free-form).In the same way, the single reflective deflecting element can be flat or curved (for example spherically, aspherically curved or free-form).

[0039] The reflectivity of the respective reflective deflection elements (or of the single reflective deflection element) can, for example, be in the range of 2 - 100% (including the range limits). Thus, the reflective deflection elements can be partially reflective or reflective.

[0040] The first spectacle lens may, in particular, have a curved rear side and / or a curved front side. The entrance portion may be formed in the rear side.

[0041] The light beams of the corresponding imaging unit are preferably guided to the deflection section by one or more reflections (in particular total internal reflections).

[0042] The image generation module can generate a monochrome image or a multi-color image.

[0043] The display device can have a control unit that controls the image generation module. In particular, the control unit can control the image generation module based on supplied image data. The image generation module or the corresponding image generator unit can, in particular, have a planar image generator, such as an LCD module, an LCoS module, an OLED module, a pLED, or a tilting mirror matrix. Each image generator can have a plurality of pixels, which can be arranged, for example, in rows and columns. Each image generator can, for example, be self-luminous or non-self-luminous.

[0044] Each imager can preferably produce a monochromatic image, with different imagers producing monochromatic images at different wavelengths.

[0045] The imaging module can, for example, comprise a polychromatic imager, a combination of two or more monochromatic imagers, or a combination of a duochromatic imager and a monochromatic imager. Typical configurations of such imaging modules with multiple imagers comprise an overlay unit that overlays the light beams of the multiple imagers into a common light beam. Such an overlay unit can be implemented, for example, as a beam splitter cube (also called an X-cube) or as a so-called rod combiner, which are known to those skilled in the art.

[0046] Since the out-coupling deflection section should be as invisible as possible and also interfere as little as possible with the light arriving from the surroundings to the viewer's eye, deflection sections are generally preferred that have high transmission in the transparent state and thus low reflectivity for the light beam(s) to be coupled out of the at least two-color image. Typical values ​​for the ratio of reflection to transmission are 50%, 30%, 10%, or 2%, uniformly across the visible wavelength range.

[0047] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations indicated, but also in other combinations or in isolation, without departing from the scope of the present invention.

[0048] The invention is explained in more detail below using exemplary embodiments with reference to the attached drawings, which also disclose features essential to the invention. These exemplary embodiments are for illustrative purposes only and are not to be interpreted as restrictive. For example, a description of an embodiment with a large number of elements or components should not be interpreted to mean that all of these elements or components are necessary for implementation. Rather, other embodiments may also contain alternative elements and components, fewer elements or components, or additional elements or components. Elements or components of different embodiments may be combined with one another unless otherwise stated. Modifications and variations described for one of the embodiments may also be applicable to other embodiments.To avoid repetition, identical or corresponding elements in different figures are designated by the same reference numerals and are not explained more than once. The figures show:

[0049] Fig. 1 is a schematic perspective view of an embodiment of the display device according to the invention;

[0050] Fig. 2 is an enlarged partial sectional view of the first spectacle lens including a schematic representation of the first image generation module according to another embodiment;

[0051] Fig. 3 is an enlarged partial sectional view of the first spectacle lens including a schematic representation of the first image generation module according to another embodiment;

[0052] Fig. 4 is an enlarged partial sectional view of the first spectacle lens including a schematic representation of the first image generation module according to another embodiment;

[0053] Fig. 5 is an enlarged partial sectional view of the first spectacle lens including a schematic representation of the first image generation module according to a further embodiment, and

[0054] Fig. 6 is an enlarged partial sectional view of the first spectacle lens including a schematic representation of the first image generation module according to another embodiment.

[0055] In the embodiment shown in Fig. 1, the display device 1 according to the invention comprises a holding device 2 which can be placed on the head of a user and which can be designed, for example, in the manner of a conventional spectacle frame, as well as a first and a second spectacle lens 3, 4 which are fastened to the holding device 2. The first spectacle lens 3 and / or the second spectacle lens 4 can be designed individually as spectacle lenses according to the invention or as a spectacle lens according to the invention. The holding device 2 with the spectacle lenses 3, 4 can be designed, for example, as sports glasses, sunglasses, and / or glasses for correcting ametropia, wherein a virtual image can be projected into the user's field of vision via the first spectacle lens 3, which can also be referred to as a multifunctional lens, as described below.For this purpose, the display device 1 comprises a first image generation module 5, which can be arranged in the region of the right temple of the holding device 2, as shown schematically in Fig. 1.

[0056] The first image generation module 5 can have a first image generator unit 7 for generating a first image, as shown schematically in Fig. 2. For this purpose, the first image generator unit 7 comprises a first planar image generation element 8, downstream of which a first image generator optics 9 is arranged. The first planar image generation element 8 can have, for example, an OLED element, an LCD element, an LCoS element, a pLED or a tilting mirror matrix, each of which comprises a multiplicity of pixels arranged, for example, in rows and columns. A single light beam L1 is shown schematically as a representative of the light beams emitted by the first planar image generation element 8.

[0057] As can further be seen from Fig. 2, a control unit 10 with, for example, a processor P and a memory M is provided for controlling the first image generation module 5. The control unit 10, which can be arranged, for example, on the holding device 2, controls the first image generation module 5 and in particular the first image generation element 8 as a function of supplied image data such that a first image is generated in accordance with the image data. The light beams L1 emitted by the first image generation element 8 pass through the first imaging optics 9 and then enter the first spectacle lens 3 via a curved rear side 11 of the latter. The region of the entrance on the rear side 11 can also be referred to as the entrance section 12.

[0058] The first spectacle lens 3 comprises a base body 13 with a first and a second interface 14, 15, a first channel interface layer 36 formed on the first interface 14, a first colored adhesive layer 37 applied to the first channel interface layer 36, and a film 17 with a polarization effect applied to the first adhesive layer 37. The film 17 is connected to the first channel interface layer 36 and thus to the base body 13 by means of the first adhesive layer 37. In the exemplary embodiment described here, the two interfaces 14, 15 of the base body 13 are curved, and the second interface 15 of the base body 13 forms the rear side 11 of the first spectacle lens 3.

[0059] The first channel boundary layer 36 is designed as an angle-dependent reflection layer 36, which reflects the light beams L1 only when their angle of incidence is 9 Erelative to the surface normal F (shown as a dashed line in Fig. 2 for the first reflection at the first boundary surface 14) of a surface element at which the reflection is to take place, is greater than a predetermined first critical angle 0 C The first channel boundary layer 36 may further be configured to be transmissive for angles of incidence in the range from 0° to a predetermined second critical angle of less than 90°. The second critical angle is less than or equal to the first critical angle 0 C .

[0060] These transmission / reflection properties are preferential for radiation in the visible wavelength range.

[0061] The angle-dependent reflection layer 36 can be designed, for example, as an interference layer system, which, for example, has alternating thin layers with higher and lower refractive indices. In the general case, the interference layer system can consist of k optical layers Si, S2, ... Sk (k > 2) made of m materials Mi ... M m (m > 2), which differ in their refractive indices Ni... Nj (j > 2). Specific examples of such an interference layer system are described, for example, in WO 2015 / 158833 A1, and therein in particular on page 4, lines 16-30, page 9, line 34 - page 10, line 31 in conjunction with Figures 3-5, and on page 11, lines 5-26 in conjunction with Figures 7-10. The corresponding disclosure is hereby incorporated into the present description.

[0062] Furthermore, the base body 13 has a buried first deflection section 18, which comprises a first reflective deflection structure 19 with a plurality of first reflective deflection elements 20, which can also be referred to as first reflective facets.

[0063] As already described, the light beams L1 enter the first spectacle lens 3 and thus the base body 13 via the entrance section 12 in the rear side 11. The light beams L1 are then guided in the base body 13 by reflection at the reflective layer 36 and by total internal reflection at the second boundary surface 15 to the first deflection section 18, so that a first light guide channel 21 is present from the entrance section 12 to the first deflection section 18.

[0064] Since the second interface 15 forms the back side 11 of the first spectacle lens 3, there is an interface to air and thus to a medium with a refractive index of 1. The design of the base body 13 and the first image generation module 5 is selected such that total internal reflection occurs at the second interface 15.

[0065] The first deflection section 18 then deflects the light beams L1 toward the rear side 11 such that the deflected light beams L1 exit the first spectacle lens 3 via the rear side 11. The area through which the light beams L1 exit can also be referred to as the exit section 22. The angle-dependent reflection layer 36 thus delimits the light-guiding channel 21 and can therefore also be referred to as the first channel boundary layer 36. Furthermore, the first adhesive layer 37 serves to bond the film 17 with a polarization effect to the base body 13, so that the polarization-dependent filter effect of the film 17 provides a desired sunglasses effect. The film 17 is preferably transparent. The side of the film 17 facing away from the base body 13 forms a front side 23 of the first spectacle lens 3.

[0066] In order to be able to realize a colored first spectacle lens 3, for example, desired for fashion reasons, the first adhesive layer 37 is designed as a colored layer 37. For this purpose, the first adhesive layer 37 can be colored. Since layer 37 is an adhesive layer, this is quite simple and can be implemented individually for each spectacle lens.

[0067] The first adhesive layer 37 may in particular be a viscous or solid layer (or intermediate layer).

[0068] The first adhesive layer 37 is usually colored with a colorant before being applied to the first channel boundary layer 36 and / or to the (preformed) cover film 17 and before the two parts are joined together. However, a variant also consists in the cover film 17 remaining on the base body 13 only during the curing process and then being removed again after the first adhesive layer 37 has reached the desired strength. A first spectacle lens formed according to this alternative is shown in Fig. 3.

[0069] The film 17 serves as a mold for applying the first adhesive layer 37. Instead of the film 17, this mold can be a permanent or reusable mold made of, for example, plastic, glass, ceramic, and / or metal. Coloring can then also be performed subsequently.

[0070] If the first adhesive layer 37 is applied using a wet-chemical process, economical production of small batch sizes is easily feasible. The colored material system forming the first adhesive layer 37 can be applied using a spin-coating process or as a spray or dip coating. Coloring the wet-chemical layer after its application to the first channel boundary layer 36 and before applying a cover film 17 is also possible.

[0071] The first adhesive layer 37 applied in this way can achieve degrees of hardness typical for hard coatings used in the manufacture of plastic ophthalmic lenses, so that the first adhesive layer 37 also assumes the function of conventional hard coatings. In this case, the first adhesive layer 37 becomes the final layer or interface for anti-reflective coatings, mirror coatings, and / or clean coatings.

[0072] Fig. 4 shows a modification of the first spectacle lens 3 according to Fig. 2. In this modification, a second adhesive layer 44 is applied to the second interface 15 of the base body 13, which adhesive layer connects a corrective lens 25 to the base body 13. The side of the corrective lens 25 facing away from the second adhesive layer 44 then forms the back side 11 of the first spectacle lens 3. The corrective lens 25 serves to correct a user's visual impairment and can, for example, be customized to the user.

[0073] The second adhesive layer 44 can be formed in the same way as the first adhesive layer 37. In particular, the second refractive index n2 of the second adhesive layer 24 can be smaller than the first refractive index m of the base body 13, so that the light beams are guided at the second interface 15 by total internal reflection.

[0074] In particular, the angles of incidence 9 ETthe light beam L1 relative to the surface normal of a surface element at which the total reflection is to take place is greater than the critical angle d GT for the occurrence of total internal reflection. The critical angle d GT is determined by the ratio of the first refractive index m , i.e. the refractive index of the material of the base body 13, to the second refractive index ns, i.e. the refractive index of the material of the second adhesive layer 44, and can be calculated from the equation ö GT = arcsin^ / n. For a given design of the base body 13 and the first image generation module 5, the angles of incidence d ET of the light beam L1 onto the second interface 15. In order for total reflection to occur, the materials of the base body 13 and the second adhesive layer 44 are selected such that at the second interface 15 the inequality n2< n * sin(0 Er ) is satisfied. Since sin(0 Er) is always less than or equal to 1, the second refractive index n2 must be less than the first refractive index m.

[0075] Fig. 5 shows a modification of the first spectacle lens 3 according to Fig. 4, in which a second channel boundary layer 38, which is designed as an angle-dependent reflection layer 38, is applied to the second interface 15. The second channel boundary layer 38 can be designed in the same way as the first channel boundary layer 36 (e.g. as an interference layer stack) and serves to guide the light bundles L1 that are reflected at it. Thus, the second channel boundary layer 38 can be designed such that it only reflects light bundles L1 if its angle of incidence relative to the surface normal of a surface element at which the reflection is to take place is greater than a predetermined third critical angle. The second channel boundary layer 38 can furthermore be designed such that it is transmissive for angles of incidence in the range from 0° to a predetermined fourth critical angle of less than 90°. The fourth critical angle is less than or equal to the third critical angle.The first and third critical angles can be the same or different. Furthermore, the second and fourth critical angles can be the same or different. These transmission / reflection properties are preferably present for radiation in the visible wavelength range.

[0076] The first image generation module 5 and the first spectacle lens 3 are designed such that a user wearing the display device 1 according to the invention on his head can perceive the first image generated by means of the first image generation module 5 as a first virtual image with his first eye (here the right eye).

[0077] The first imaging unit 7 can be configured to generate and output a monochromatic (and thus single-color) image. However, it can also be configured to generate and output a multicolor image.

[0078] Furthermore, it is possible to provide several image generator units 7, 7' and 7" (Fig. 6) which, for example, generate and output a red, green and blue partial image, which is then superimposed by means of a superposition unit 35 (for example a color generator cube) to form a common beam L1, as shown for the first image generation module 5 in Fig. 6.

[0079] Depending on the reflectivity of the first deflection elements 20, the first virtual image can be perceived by the user in superimposition with the surroundings. With very high reflectivity, and in particular with a reflectivity of 100%, the user can perceive only the first virtual image and not the surroundings, at least in the region of the first deflection section 18, if a certain distance between the first deflection elements 20 is not exceeded. If the certain distance between adjacent deflection elements 20 is exceeded, ambient light can reach the eye unhindered between them, so that even with 100% reflectivity of the deflection elements 20, a view of the surroundings is possible, resulting in a quasi-perforated / segmented 100% mirror.

[0080] In the display device 1 according to the invention, the virtual image is reflected into the user's field of vision via the first spectacle lens 3. Of course, reflection via the second spectacle lens 4 is also possible. Furthermore, the display device 1 can be designed such that information or virtual images are reflected via both spectacle lenses 3, 4. The reflection can be effected in such a way that a three-dimensional image impression is created. However, this is not absolutely necessary. The spectacle lenses 3, 4 can have a refractive power of zero or a refractive power different from zero (in particular for correcting ametropia). In particular, both the front side 23 and the back side 11 can be curved. The front side 23 is in particular spherically curved.If the spectacle lens 3, 4 has a refractive power other than zero to correct a visual impairment, the curvature of the back surface 11 is generally selected accordingly to achieve the corresponding correction. The back surface 11 can have a curvature that deviates from spherical. The holding device 2 does not have to be designed as a spectacle-like holding device. Any other type of holding device is also possible, allowing the display device 1 to be placed and worn on the head.

Claims

Patent claims 1 . Spectacle lens for a display device (1) that can be placed on the head of a user and generates an image, wherein the spectacle lens (3) has a front side (23) and a back side (11), an entry section (12) and a deflection section (18) spaced from the entry section (12), as well as a light guide channel (21) that guides light beams (L1) of the generated image, which are coupled into the spectacle lens (3) via the entry section (12) of the spectacle lens (3), in the spectacle lens (3) through at least one reflection to the deflection section (18), from which they are deflected in order to exit from the spectacle lens (3) via the back side (11), wherein the light guide channel (21) has a base body (13) and a first channel boundary layer (36), wherein the base body (13) has a first boundary surface (14) and a second boundary surface (15), one of which is from the front side (23) and the other facing away from the rear side (11),wherein the first channel boundary layer (36) is applied to the first boundary surface (14) and is designed as an angle-dependent reflection layer which reflects the light beams (L1) only if their angle of incidence is greater than a predetermined first critical angle, characterized in that a first colored layer (37) is applied to the first channel boundary layer (36), which is designed as an adhesive layer or as a lacquer layer.

2. Spectacle lens according to claim 1, wherein at least one further layer is applied to the first colored layer (36).

3. Spectacle lens according to claim 2, wherein the at least one further layer (17) provides a polarization-dependent filter effect, is designed as a colored layer (17) and / or as a phototropic layer.

4. Spectacle lens according to claim 2 or 3, wherein the at least one further layer (17) is formed as a film.

5. Spectacle lens according to one of the above claims, wherein the first colored layer is formed as a viscous or solid layer.

6. Spectacle lens according to one of the above claims, wherein the light guide channel (21) further comprises a second channel boundary layer (38) which is applied to the second boundary surface (15) and is designed as an angle-dependent reflection layer which reflects the light beams (L1) only if their angle of incidence is greater than a predetermined third critical angle.

7. Spectacle lens according to claim 6, wherein a second colored layer (44) is applied to the second channel boundary layer (38), which is designed as an adhesive layer or as a lacquer layer.

8. Spectacle lens according to one of claims 1 to 5, wherein the base body (13) is formed from a first material with a first refractive index (m) and the light guide channel (21) further comprises a second channel boundary layer (44) which is applied directly to the second interface (15), wherein the second channel boundary layer (44) is formed from a second material with a second refractive index (ns), and wherein the second refractive index (ns) is smaller than the first refractive index (m), so that reflections of the light beams (L1) at the boundary between the second channel boundary layer (44) and the second interface (15) are total reflections.

9. Spectacle lens according to claim 8, wherein the second channel boundary layer (44) is formed as a colored layer.

10. Spectacle lens according to claim 8 or 9, wherein the second channel boundary layer (44) is formed as an adhesive layer or as a lacquer layer. 11 . Display device with a holding device (2) that can be placed on the head of a user, an image generation module (5) that is fastened to the holding device (2) and that generates an image, a spectacle lens (3) fastened to the holding device (2) according to one of the above claims, wherein the generated image is coupled into the spectacle lens (3) via the entry section (12), guided in the spectacle lens (3) by at least one reflection to the deflection section (18) and deflected at the first deflection section (18) in order to be output from the spectacle lens via the rear side (11). (3) so that the user can perceive it as a virtual image when the holding device (2) is placed on the head.

12. A method for producing a spectacle lens according to one of claims 1 to 10, in which a base body (13) which has a first interface (14), a second interface (15) and a deflection section (18) is provided, a first channel interface layer (16) is applied to the first interface (14) and is designed as an angle-dependent reflection layer which only reflects a light beam (L1) if its angle of incidence is greater than a predetermined first critical angle, and in which a first colored layer which is designed as an adhesive layer or as a lacquer layer is applied to the first channel interface layer (16).

13. The method according to claim 12, wherein the first channel boundary layer (16) is applied directly to the first interface (14).

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