Spectacle lens for a display device which can be placed on the head of a user and which generates an image, and display device comprising 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, wherein the first reflection surface (26, 27) has at least one first transparency zone (T1; T2), wherein undesired stray light (F1; F2), which is guided in the light guiding channel (21), can emerge from the first shell (13) and can enter the second shell (24; 25) via the at least one first transparency zone (T1; T2), and wherein the first reflection surface (26; 27) comprises the at least one first reflection zone (R1; R2, R3) and / or the at least one first reflection region (RB1; RB2, RB3, RB4) between the first and second shells (13; 23, 24) on the portion or portions on which the stray light (F1; F2) propagating in the second shell (24; 25) may impinge upon such that the stray light (F1; F2) is reflected off the portion or portions and is unable to re-enter the first shell (13).

Description

[0001] Spectacle lens for a display device that can be placed on a user's head and produces an image, and display device with such a spectacle lens

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

[0003] A spectacle lens of the type mentioned above is known from WO 2015 / 158833 A1. Such spectacle lenses can be used, for example, in a display device that is placed on a user's head and generates an image, in order to provide so-called data glasses.

[0004] The multi-layered structure allows for additional functionalities, such as tints, sun protection and individual front and / or back geometries for vision correction, without impairing the light guidance in the shell to the waveguide (hereinafter also referred to as waveguide or wave conductor).

[0005] If the light guidance within the waveguide is to be achieved via total internal reflection, the light-guiding waveguide must be optically decoupled from the additional (preferably outer) shells. This can be achieved, for example, by a sufficiently large difference in the refractive indices of the materials at the interfaces or by suitable interference mirrors, e.g., using dielectric thin-film technology, so that the lens has reflective surfaces that cause the reflection of the light beams in the waveguide for light guidance.

[0006] One possibility is to manufacture the waveguide, outer and inner shell from the same or similar materials and to bond them together over their entire surface using an adhesive with a significantly lower refractive index than that of the waveguide material, thus ensuring the necessary refractive index difference at the interface.

[0007] Alternatively, one or both shells could of course be made of a correspondingly low-refractive-index material.

[0008] When using interference mirrors for decoupling, the coatings are typically applied to the entire surface of the shell or waveguide before the two are joined. Since the adhesive is not responsible for decoupling in this case, its refractive index is not a limiting factor, and other criteria, such as adhesion strength, transparency, or processability, can be prioritized during selection.

[0009] If the parting line or the surface of the waveguide and / or the other shells exhibits changes in curvature, e.g. to influence the light guidance in the waveguide, an index match of the adhesive on the waveguide and / or shell is useful, as this positively influences the transparency performance.

[0010] Figure 3 shows an example of the structure of a multi-layered spectacle lens 3'. The light beam L1, schematically represented by a solid line, represents the path of the useful rays that are reflected in the areas R1, R2, and R3 for light guidance in the waveguide 13. The ray shown by the dotted line F2 and the ray shown by the dashed line F1 represent stray light paths that lead to unintended and undesirable double images, blurring, ghosting, etc.

[0011] Based on this, the object of the invention is to provide a spectacle lens of the type mentioned above with which the difficulties described above can be overcome as completely as possible. Furthermore, a display device with such a spectacle lens is to be provided.

[0012] The invention is defined in independent claims 1 and 16. Advantageous embodiments are specified in dependent claims.

[0013] A spectacle lens is provided for a display device that can be placed on a user's head and generates an image. The spectacle lens has a front and a back, an entry section and a deflection section spaced apart from the entry section, as well as a light guiding channel. The light guiding channel extends from the entry section to the deflection section along a first direction and guides light beams of the generated image, which are coupled into the spectacle lens via the entry section, through at least one reflection to the deflection section, from which they are deflected to exit the spectacle lens via the back.

[0014] The spectacle lens has a multi-layered structure and comprises at least a first and a second layer, the two layers being connected to each other (preferably across their entire surface) and a first reflective surface being formed between them. The light-guiding channel runs within the first layer, and the first reflective surface extends from the entry section to the deflection section, the first reflective surface having at least one first reflection zone onto which the light beams of the generated image strike and are reflected as they travel through the light-guiding channel.

[0015] The first reflective surface further comprises at least one first reflection area, located adjacent to the at least one first reflection zone in the first direction, and at least one first transparency zone. Through the at least one first transparency zone, unwanted stray light guided in the light channel can exit the first shell and enter the second shell, with the first reflective surface between the first and second shells having at least one first reflection zone and / or at least one first reflection area at the section(s) upon which the stray light propagating in the second shell can strike, such that the stray light is reflected at the section(s) and cannot re-enter the first shell.

[0016] This allows disruptive and unwanted effects caused by false lighting, such as unintentional double images, blurring, and reflections, to be effectively suppressed or significantly reduced.

[0017] False light, in this context, refers specifically to light coupled into the lens of the eyeglass that does not serve to create the image, such as scattered light.

[0018] The at least one first transparency zone can be formed at least partially adjacent to the at least one first reflection zone and / or can be formed at least partially adjacent to the at least one first reflection area. It can also be said that the at least one first transparency zone and the at least one first reflection zone overlap at least partially and / or that the at least one first transparency zone and the at least one first reflection area overlap at least partially.

[0019] This is possible, for example, if the first transparency zone has an angle-selective effect and the angles of incidence of the light beams of the generated image onto the first transparency zone differ from the angles of incidence of the unwanted stray light onto the first transparency zone. In the overlap area, the stray light can thus escape from the first layer, while the light beams of the generated image can be reflected.

[0020] The first transparency zone can, for example, have an interference layer system or be designed as an interference layer system. Preferably, in this case, the first reflection zone and / or the first reflection area can also have an interference layer system or be designed as an interference layer system. Preferably, the first transparency zone and the first reflection zone and / or the first reflection area can both have a common interference layer system or be designed as a common interference layer system.

[0021] The at least one first transparency zone can be formed entirely adjacent to the at least one first reflection zone, or entirely adjacent to the at least one first reflection area. In this case, there is no overlap between the at least one first transparency zone and the at least one first reflection zone, nor is there any overlap between the at least one first transparency zone and the at least one first reflection area.

[0022] The second shell can have an absorber (e.g. a radiation trap, an absorber layer, an absorber lacquer, a black layer, etc.) onto which the false light propagating in the second shell hits and is then absorbed by the absorber.

[0023] The extent of each first transparency zone can be smaller in the first direction than the extent of the first reflective surface in the first direction.

[0024] The extent of each first transparency zone can be smaller in the first direction than the extent of each first reflection zone in the first direction.

[0025] The extent of each first transparency zone can be smaller in the first direction than the extent of each first reflection zone in the first direction.

[0026] The first reflective surface can have exactly one first transparency zone or exactly two first transparency zones.

[0027] The first reflective surface can be designed as a continuous and / or contiguous surface, except for at least one first transparency zone.

[0028] The first transparency zone, at least one of which can have a higher transparency than the first reflective surface.

[0029] The at least one first transparency zone can have a transparency greater than 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, and preferably a transparency of 100%. The transparency preferably refers to the wavelengths at which the image is generated by the display device and / or to the visible spectral range. The aforementioned transparency can also be present in the IR wavelength range, in particular in the wavelength range from 780 to 1400 nm, in the wavelength range from 1400 to 3000 nm, and / or in the wavelength range from 3000 nm to 1 mm.

[0030] The first transparency zone, at least one, can be formed as a gap in the first reflective surface.

[0031] The spectacle lens can have a third layer, in which the first and third layers are bonded together (preferably across their entire surface) and a second reflective surface is formed between them. Thus, the first layer can be described as an inner channel layer located between the second and third layers.

[0032] The second reflective surface can have at least one second reflection zone onto which the light beams of the generated image strike during guidance in the light guidance channel and are reflected there, wherein the second reflective surface can further have at least one second reflection area which lies next to the at least one second reflection zone in the first direction.

[0033] The second reflective surface can have at least one second transparency zone, whereby unwanted stray light, which is guided in the light guidance channel, can exit the first shell and enter the third shell via the at least one second transparency zone.

[0034] Furthermore, the second reflective surface between the first and third shell can have at least one second reflection zone and / or at least one second reflection area on the section(s) on which the false light propagating in the third shell can hit, so that the false light is reflected on the section(s) and cannot re-enter the first shell.

[0035] The second transparency zone can be formed either completely next to the at least one second reflection zone or completely next to the at least one second reflection area.

[0036] The at least one second transparency zone can be formed as a gap in the second reflective surface. However, it is also possible that the second transparency zone is formed at least partially adjacent to the at least one second reflective zone and / or at least partially adjacent to the at least one second reflective area. One can also say that the at least one second transparency zone and the second reflective zone overlap at least partially and / or that the at least one second transparency zone and the at least one second reflective area overlap at least partially.

[0037] This is possible, for example, if the at least one second transparency zone acts angle-selectively and the angles of incidence of light beams from the generated image onto the at least one second transparency zone differ from the angles of incidence of the unwanted stray light onto the at least one second transparency zone. In the overlap area, the stray light can thus escape from the first layer, while the light beams of the generated image can be reflected.

[0038] The second transparency zone can, for example, have an interference layer system or be designed as an interference layer system. Preferably, in this case, the second reflection zone and / or the second reflection area can also have an interference layer system or be designed as an interference layer system. Preferably, the second transparency zone and the second reflection zone and / or the second reflection area can both have a common interference layer system or be designed as a common interference layer system.

[0039] The second shell can be an outer shell, which, when the lens is used as intended in the display device, faces away from the user's head. Alternatively, the second shell can be an inner shell, which, when the lens is used as intended in the display device, faces the user's head.

[0040] The third shell can also be an outer or inner shell.

[0041] Preferably, one of the two shells (= second and third shell) is the outer shell and the other of the two shells is the inner shell.

[0042] The first reflective surface and / or the second reflective surface can be realized by a refractive index step, which ensures total internal reflection.

[0043] The refractive index step can occur between the first shell and a layer (e.g., an adhesive layer) located between the first and the second or third shell. The first reflective surface and / or the second reflective surface are thus formed by the interface between the first shell and the layer (e.g., the adhesive layer).

[0044] The refractive index jump can occur between the first shell and the second or third shell.

[0045] The first reflective surface and / or the second reflective surface are thus formed by the boundary between the first shell and the second or third shell.

[0046] The first and / or second reflective surfaces can be designed, for example, to reflect light beams only when their angle of incidence is greater than a predetermined first critical angle. Furthermore, the first and / or second reflective surfaces can be designed to be transmissive for angles of incidence in the range of 0° up to a predetermined second critical angle of less than 90°. The second critical angle is less than or equal to the first critical angle.

[0047] These transmission / reflection properties are predominantly present for radiation from the visible wavelength range.

[0048] The first limiting angle can be, for example, in the range of 45° to 80°, preferably in the range of 50° to 60°. The second limiting angle can be, for example, in the range of 30° to 70°, preferably in the range of 35° to 45°.

[0049] The first and / or second reflective surface can have an interference layer system or be designed as an interference layer system. The interference layer system can be made of at least two different materials with different refractive indices. In particular, the interference layer system can have two, three, four, five, or more different materials. The refractive indices of the materials can be in the range of 1.3 to 2.5 at a wavelength of 546 nm.

[0050] Each of the bowls can be made of glass or plastic.

[0051] The spectacle lens can have an exit point on its back surface through which the deflected light beams exit the lens. Furthermore, the deflecting section can redirect the light beams, which have been guided up to it, towards the exit point in such a way that they exit the lens through the exit point and are thus coupled out of the lens. The deflecting section and the exit point can be spatially separate sections. However, it is also possible for the deflecting section and the exit point to coincide spatially, for example, if the deflecting section is designed as a surface grating.

[0052] In a spectacle lens, the deflection section can have a single reflective or partially reflective deflection element, or several reflective and / or partially reflective deflection elements arranged side by side. With several reflective or partially reflective deflection elements arranged side by side, a desired deflection function and, if necessary, a certain imaging function of the deflection section can be achieved, for example, in a Fresnel-like manner (this can, of course, also be achieved with a single reflective or partially reflective deflection element). The reflective or partially reflective deflection elements can be reflective or partially reflective surfaces, which can also be referred to as reflective or partially reflective facets. The reflective or partially reflective surfaces can each be planar. However, it is also possible for the reflective or partially reflective surfaces to be...The partially reflective surface sections themselves are curved (for example, spherically or aspherically curved, or freeform). Similarly, the single reflective or partially reflective deflecting element can be flat or curved (for example, spherically or aspherically curved, or freeform).

[0053] The reflectivity of the respective reflective deflection elements (or the single reflective deflection element) can, for example, range from 2% to 100% (including the limits of this range). Thus, the reflective deflection elements can be partially reflective or fully reflective.

[0054] Each of the shells can be designed as a plane-parallel plate, as a plate with one curved side, or as a plate with two curved sides. The facing sides of two shells connected to each other (e.g., by means of an adhesive layer) can preferably have complementary curvatures.

[0055] The spectacle lens according to the invention can in particular have a curved back surface and / or a curved front surface. The entry section can be formed in the back surface and / or in the first shell.

[0056] The light beams of the image generation module are preferably guided through one or more reflections (especially total internal reflections) to the deflection section.

[0057] In the spectacle lens according to the invention, the first and second shells can be made of the same or similar materials and bonded together (preferably over the entire surface) by means of an adhesive with a (preferably significantly) lower refractive index than that of the first shell, in order to ensure the necessary difference in refractive index at the interface to generate the first reflective surface. The same can be achieved for the first and third shells, in order to ensure the necessary difference in refractive index at the interface to generate the second reflective surface.

[0058] Alternatively and / or additionally, the second and / or third shell itself can be made of a correspondingly low-refractive-index material in order to ensure the necessary refractive index difference at the interface to generate the first or second reflective surface.

[0059] When using interference layer systems or interference mirrors, the necessary coatings can also be applied to the entire surface of the first or second (or third) shell (preferably with the exception of the corresponding transparency zone(s), or, for example, including the corresponding transparency zone(s) in the case of angle-selective transparency zones) before the first shell is bonded to the second (or third) shell. Since the adhesive is not responsible for creating the first or second reflective surface, its refractive index is not restricted, and other criteria, such as adhesion strength, transparency, and / or processability, can be prioritized in its selection.

[0060] If the parting line or the surface of the first shell and / or the subsequent shells exhibits changes in curvature, e.g. to influence the light transmission in the first shell, an index match of the adhesive to the first shell and / or the second or third shell is useful, as this positively influences the transparency performance.

[0061] Furthermore, a display device is provided comprising a holding device (e.g., in the form of eyeglasses) that can be placed on the user's head, an image generation module attached to the holding device which generates an image, and a spectacle lens according to the invention attached to the holding device. The generated image can be coupled into the spectacle lens via the entry section, guided within the spectacle lens (preferably in the first lens shell) by at least one reflection to the deflection section, and deflected at the first deflection section to exit the spectacle lens via the back side, so that the user can perceive it as a virtual image when the holding device is placed on the user's head. The image generation module can generate a monochrome or a multi-colored image. The display device can include 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.

[0062] The image generation module and / or an image sensor unit of the image generation module may, in particular, comprise a planar image sensor, such as an LCD module, an LCoS module, an OLED module, a pLED, or a tilting mirror matrix. Each image sensor may have a plurality of pixels, which may be arranged, for example, in rows and columns. Each image sensor may, for example, be self-illuminating or non-self-illuminating.

[0063] Each image sensor can preferentially produce a monochromatic image, while different image sensors can produce monochromatic images with different wavelengths.

[0064] The image generation module can, for example, comprise a polychromatic image source, a combination of two or more monochromatic image sources, or a combination of a duochromatic and a monochromatic image source. Typical configurations of such image generation modules with multiple image sources include a superposition unit that combines the light beams of the multiple image sources into a single, common light beam. Such a superposition unit can be implemented, for example, as a beam splitter cube (also called an X-cube) or as a so-called rod combiner, both of which are known to those skilled in the art.

[0065] Since the diverting section should be as invisible as possible and should also have as little impact as possible on the light reaching the viewer's eye from the surroundings, diverting sections with high transmission and, consequently, low reflectivity for the image's light beam(s) are generally preferred. Typical reflectance-to-transmission ratios are 50%, 30%, 10%, or 2%, distributed evenly across the visible wavelength range.

[0066] 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.

[0067] 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:

[0068] Fig. 1 shows a schematic perspective view of an embodiment of the display device according to the invention;

[0069] Fig. 2 shows an enlarged partial sectional view of the first spectacle lens including a schematic representation of the first image generation module according to Fig. 1;

[0070] Fig. 3 shows an enlarged partial sectional view of a spectacle lens not according to the invention, including a schematic representation of an image generation module;

[0071] Fig. 4 shows an enlarged partial sectional view of a spectacle lens not according to the invention, including a schematic representation of an image generation module;

[0072] Fig. 5 shows 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 of the invention, and

[0073] Fig. 6 shows 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 according to the invention.

[0074] In the embodiment shown in Fig. 1, the display device 1 according to the invention comprises a holding device 2 that can be placed on the user's head and which may, for example, be designed in the manner of a conventional eyeglass frame, as well as a first and a second lens 3, 4, which are attached to the holding device 2. The first lens 3 and / or the second lens 4 can each be designed as a lens according to the invention. The holding device 2 with the lenses 3, 4 can, for example, be designed as sports glasses, sunglasses, and / or glasses for correcting a visual impairment, wherein a virtual image can be projected into the user's field of vision via the first lens 3, which can also be referred to as a multifunctional lens, as described below.The display device 1 includes a first image generation module 5, which can be arranged in the area of ​​the right temple of the holding device 2, as shown schematically in Fig. 1.

[0075] The first image generation module 5 can include a first image sensor unit 7 for generating a first image, as schematically illustrated in Fig. 2. For this purpose, the first image sensor unit 7 comprises a first planar image generation element 8, to which a first image sensor optic 9 is arranged. The image sensor optic 9 can also be omitted. The first planar image generation element 8 can, for example, comprise an OLED element, an LCD element, an LCoS element, a pLED, or a tilting mirror matrix, each comprising a plurality of pixels arranged, for example, in rows and columns. A single light beam L1 is schematically depicted as a representative of the light beams emitted by the first planar image generation element 8.

[0076] As can be further seen in 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, for example, be arranged on the holding device 2, controls the first image generation module 5, and in particular the first image generation element 8, depending on the supplied image data, so that a first image is generated according to the image data. The light beams L1 emitted by the first image generation element 8 pass through the first image transmitter optics 9 and then enter the first spectacle lens 3. The area of ​​entry can also be referred to as the entry surface 12.

[0077] The first spectacle lens 3 is multi-layered and comprises a channel shell 13, an outer shell 24, and an inner shell 25. The channel shell 13 is the middle shell located between the outer shell 24 and the inner shell 25. The shells 13, 24, and 25 are connected to each other in such a way that a reflective surface 26 (hereinafter also referred to as the outer reflective surface 26) is provided between the channel shell 13 and the outer shell 24, and a reflective surface 27 (hereinafter also referred to as the inner reflective surface 27) is provided between the channel shell 13 and the inner shell 25. The two reflective surfaces 26 and 27 are shown as dashed lines in Fig. 2.

[0078] In the embodiment described here, all three shells 13, 24, 25 are curved to provide a curved spectacle lens 3. The side of the outer shell 24 facing away from the channel shell 13 forms the front 23 of the first spectacle lens 3, and the side of the inner shell 25 facing away from the channel shell 13 forms the back 11 of the first spectacle lens 3. The outer reflective surface 26 can be implemented by an angle-dependent reflective layer 26, which reflects the light beams L1 only when their angle of incidence 9 E with respect to the surface normal F (shown as a dashed line in Fig. 2 for the first reflection at the first interface 14) of a surface element at which the reflection is to take place, is larger than a predetermined first critical angle 0 GThe outer reflective surface 26 can further be configured to be transmissive for angles of incidence in the range from 0° up 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°. G .

[0079] These transmission / reflection properties are predominantly present for radiation from the visible wavelength range.

[0080] The angle-dependent outer reflective surface 26 can, for example, be designed as an interference layer system, which may have 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 with respect to their refractive indices Ni... Nj (j > 2), may be formed. Concrete examples of such an interference layer system are described, for example, in WO 2015 / 158833 A1, and there in particular on page 4, lines 16-30, page 9, line 34 - page 10, line 31 in conjunction with Figures 3-5, as well as on page 11, lines 5-26 in conjunction with Figures 7-10. The corresponding disclosure is hereby incorporated into the present description.

[0081] The inner reflective surface 27 can be designed in the same way as the outer reflective surface 26.

[0082] It is also possible that the outer and / or inner reflective surface 26, 27 is realized by a transparent adhesive layer whose refractive index is lower than that of the channel shell 13, the refractive indices being chosen such that the light beams in the channel shell 13 are guided by total internal reflection. The outer and / or inner reflective surface 26, 27 is thus formed by the interface between the channel shell 13 and the respective adhesive layer.

[0083] It is also possible that the outer and / or inner reflective surface 26, 27 is realized by a refractive index step between channel shell 13 and outer shell 24 or between channel shell 13 and inner shell 25, where the refractive index of the outer shell 24 / inner shell 25 is lower than the refractive index of the channel shell. The exact refractive index values ​​are chosen such that the light beams in the channel shell 13 are guided by total internal reflection. The outer and / or inner reflective surface 26, 27 is thus formed by the interface between the channel shell 13 and the outer shell 24 / inner shell 25.

[0084] Furthermore, the channel shell 13 has a buried first deflection section 18, which includes several partially reflective deflection elements 19, which can also be referred to as partially reflective facets 19.

[0085] As previously described, the light beams L1 enter the first lens 3 via the entrance surface 12. The entrance surface 12 is formed on a lateral entrance section 28 of the channel shell 13, which, in the embodiment described here, projects laterally beyond the outer and inner shells 24, 25. In addition to the entrance surface 12, the lateral entrance section 28 has a (here curved) deflecting surface 29, which deflects the light beams L1 in a first direction (here the y-direction) towards the deflecting section 18 such that the light beams L1 are guided by reflections at both reflective surfaces 26, 27 in the channel shell 13 to the first deflecting section 18. For this guidance to occur in the channel shell 13, both reflective surfaces 26, 27 extend from the entrance section 28 to the first deflecting section 18.

[0086] The first deflection section 18 then deflects the light beams L1 such that the deflected light beams L1 exit the first lens 3 via the rear surface 11, thus creating a virtual image that the user can perceive with their eye A. The area through which the light beams L1 exit can also be referred to as the exit section 22.

[0087] Thus, in the channel shell 13 there is a first light guiding channel 21, which extends along the first direction from the entry section 12 to the first deflection section 18.

[0088] In the embodiment described here, the outer reflective surface 26 has an outer reflection zone R1, onto which the light beams L1 strike during their guidance in the light channel 21 and are consequently reflected. Furthermore, the outer reflective surface 26 extends from the outer reflection zone R1 to the first deflection section 18. This area of ​​the outer reflective surface 26 is subsequently referred to as the outer reflection area RB1. The outer reflection zone R1 and the outer reflection area RB1 together form the reflective surface 26. Structurally, the outer reflection zone R1 and the outer reflection area RB1 do not differ; only the section of the outer reflective surface 26 onto which the light beams L1 strike during their guidance in the light channel 21 is referred to as the outer reflection zone R1.The inner reflective surface 27 has two inner reflection zones R2 and R3, onto which the light beams L1 strike during their guidance in the light channel 21 and are consequently reflected there. Furthermore, the inner reflective surface 27 includes an inner reflection area RB2, which adjoins the inner reflection zone R2, and two further inner reflection areas RB3 and RB4, which adjoin both sides of the inner reflection zone R3. Structurally, the two inner reflection zones R2 and R3 and the inner reflection areas RB2–RB4 are not distinct; only the sections of the inner reflective surface 27 onto which the light beams L1 strike during their guidance in the light channel 21 are referred to as inner reflection zones R2 and R3.

[0089] The reflection zones R1-R3, which can also be referred to as footprints R1-R3, are shown in dashed and bold in Fig. 2.

[0090] As further shown in Figure 2, the two reflective surfaces 26, 27 extend from the inlet section 12 to the first deflection section 18 (with the exception of two transparency zones T1, T2, which are described in more detail below) and in the first direction from the inlet section 12 to the first deflection section 18 significantly further than the reflection zones R1-R3. In other words, the extent of the outer reflective surface 26 in the first direction is significantly greater than the extent of the reflection zone R1 in the first direction. Similarly, the extent of the inner reflective surface 27 in the first direction is significantly greater than the extent of the reflection zones R2, R3 in the first direction.

[0091] The outer reflective surface 26 has an outer transparency zone T1, which is located adjacent to the outer reflection zone R1. The outer transparency zone T1 can be directly adjacent to the outer reflection zone R1 (or any other section of the outer reflective surface 26) or spaced apart from the outer reflection zone R1 (or any other section of the outer reflective surface 26). The outer transparency zone T1 is designed such that no reflection of light beams guided in the channel shell 13 occurs in this region of the outer reflective surface 26. Instead, light beams guided in the channel shell 13 that strike the outer transparency zone T1 are transmitted and thus enter the outer shell 24. The position and extent (especially in the first direction) of the outer transparency zone T1 are chosen such that unwanted stray light F2 (dotted line in Fig. 2) is prevented from entering the outer shell 24.2) in this zone, light is coupled out of the channel shell 13 and coupled into the outer shell 24. At the same time, the outer transparency zone T1 lies next to the outer reflection zone R1, so that the (desired) light beams L1 are not coupled out of the channel shell 13, but are guided in the channel shell 13 in the manner described.

[0092] The extent of the outer reflective surface 26 in the first direction is significantly larger than the extent of the outer transparency zone T1 in the first direction.

[0093] As shown in Fig. 2, the stray light F2 strikes the front surface 23 at such an angle that, due to total internal reflection, it is deflected towards the channel shell 13 and, in addition to the outer reflection zone R1, strikes the interface between the channel shell 13 and the outer shell 24. However, since the outer reflection surface 26 (here outer reflection area RB1) is formed in this area, even though it is not a reflection zone required for guiding the light beams L1, the stray light F2 is reflected at the outer reflection surface 26 towards the front surface 23. Thus, the stray light F2 is guided in the outer shell 24 to the left edge 30, or to the edge 30 of the first lens 3 facing away from the entrance section 28. A suitable absorber 31 is formed on the left edge 30 (e.g. an applied absorber or black lacquer 31) which absorbs the unwanted stray light F2 (preferably efficiently).This allows disturbing stray light phenomena (such as unintentional double images, blurring, ghosting, etc.) to be effectively suppressed or significantly reduced.

[0094] The inner reflective surface 27 has an inner transparency zone T2 to couple unwanted stray light F1 (dashed line in Fig. 2) out of the channel shell 13 and couple it into the inner shell 24. In the embodiment described here, the inner transparency zone T2 lies between the two inner reflection zones R2, R3. The inner transparency zone T2 can also be located in or on any other section of the inner reflective surface 27.

[0095] The stray light F1 coupled into the inner shell 25 strikes the absorber 31 in Fig. 2 without further reflections. This naturally depends on the specific dimensions of the first lens 3. It could therefore also be the case that the stray light F1 coupled into the inner shell 25 is guided to the absorber 31 by reflections at the rear surface 1 1 and the inner reflective surface 27. This would effectively suppress or significantly reduce disturbing stray light phenomena.

[0096] Furthermore, the extent of the inner reflective surface 27 in the first direction is significantly larger than the extent of the inner transparency zone T2 in the first direction. To illustrate the inventive effect of effectively suppressing or reducing the disturbing scattered light phenomena, Fig. 3 shows a spectacle lens 3' in the same manner as in Fig. 2, except that the two reflective surfaces 26, 27 are designed as continuous layers and thus without transparency zones. As can be seen in Fig. 3, the stray light F1 and F2 would reach the user's eye A and thus lead to undesirable scattered light phenomena.

[0097] If the spectacle lens 3' were designed according to Figure 4 such that the reflective surfaces 26, 27 are only formed in the reflection zones R1 -R3, new false light paths can result, so that the false light F1 , F2 re-enters the channel shell 13 and can be coupled out via the coupling section 18 in the direction of the eye A.

[0098] 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 their head can perceive the first image generated by means of the first image generation module 5 as the first virtual image with their first eye A (here the right eye).

[0099] The first image sensor unit 7 can be configured to generate and output a monochromatic (and therefore single-color) image. However, it can also be configured to generate and output a multi-color image.

[0100] Furthermore, it is possible to provide several image generation units 7, 7' and 7" (Fig. 5) which, for example, generate and output a red, green and blue partial image, which is then superimposed to form a common beam L1 by means of a superposition unit 35 (for example, a beam splitter cube - also called X-Cube - or a so-called rod combiner), as shown for the first image generation module 5 in Fig. 5.

[0101] Figure 6 shows a modification of the first spectacle lens 3 according to Figure 2. In this modification, the inner transparency zone T2 (whose extent in the first direction is indicated by a curved bracket) and the inner reflection zone RB2 partially overlap. This is achieved by designing the inner transparency zone T2 (at least in the overlap area) as an angle-selective transparency zone T2, which reflects stray light F1 that strikes the inner transparency zone T2 at a different angle than the light beams L1. Such an angle-selective transparency zone T2 can, for example, be implemented as an interference layer system.

[0102] Of course, it is also possible that the inner transparency zone T2 completely overlaps with the inner reflection area RB2. In principle, the inner transparency zone T2 can partially or completely overlap with any section of the inner reflection surface 27. The same applies to the outer transparency zone T1 and the outer reflection surface 26.

[0103] Depending on the reflectivity of the deflecting elements 19, the user can perceive the first virtual image superimposed on the surroundings. With very high reflectivity, and especially with a reflectivity of 100%, the user can only perceive the first virtual image and not the surroundings in the area of ​​the first deflecting section 18, provided a certain distance between the first deflecting elements 19 is not exceeded. If this certain distance between adjacent deflecting elements 19 is exceeded, ambient light can pass unhindered between them to the eye, so that even with 100% reflectivity of the deflecting elements 19, a view of the surroundings is possible, effectively creating a perforated / segmented 100% mirror.

[0104] In the display device 1 according to the invention, the virtual image is projected into the user's field of vision via the first lens 3. Projection via the second lens 4 is also possible. Furthermore, the display device 1 can be designed such that information or virtual images are projected via both lenses 3 and 4. The projection can be arranged to create a three-dimensional image impression. However, this is not mandatory.

[0105] The lenses 3, 4 can have a refractive power of zero or a non-zero refractive power (particularly for correcting a refractive error). In particular, both the front surface 23 and the back surface 11 can be curved. The front surface 23 is, in particular, spherically curved. If the lens 3, 4 has a non-zero refractive power to correct a refractive error, the curvature of the back surface 11 is usually chosen accordingly to achieve the desired correction. The back surface 11 can have a curvature other than spherical.

[0106] The holding device 2 need not be designed as a spectacle-like holding device. Any other type of holding device is also possible, with which the display device 1 can be placed on and worn on the head.

Claims

Patent claims 1. Spectacle lens for a display device (1) that can be placed on a user's head and generates an image, wherein the spectacle lens (3) has a front (23) and a back (11), an entry section (28) and a deflection section (18) spaced apart from the entry section (28), as well as a light guiding channel (21), wherein the light guiding channel (21) extends from the entry section (28) to the deflection section (18) along a first direction and guides light beams (L1) of the generated image, which are coupled into the spectacle lens (3) via the entry section (28) of the spectacle lens (3), in the spectacle lens (3) by at least one reflection to the deflection section (18), from which they are deflected to exit the spectacle lens (3) via the back (11), wherein the spectacle lens (3) is multi-layered and has a first and second layer (13; 24, 25), wherein the two shells (13;24, 25) are connected to each other and a first reflective surface (26, 27) is formed between them, wherein the light guiding channel (21) runs in the first shell (13) and the first reflective surface (26, 27) extends from the entry section (28) to the deflection section (18), wherein the first reflective surface (26, 27) has at least one first reflection zone (R1; R2, R3) onto which the light beams (L1) of the generated image strike during their guidance in the light guiding channel (21) and are reflected there, wherein the first reflective surface (26, 27) furthermore has at least one first reflection area (RB1; RB2, RB3, RB4) which lies in the first direction next to the at least one first reflection zone (R1; R2, R3), characterized in that the first reflective surface (26, 27) has at least one first transparency zone (T1; T2) exhibits, wherein unwanted stray light (F1; T2) is filtered out via at least one first transparency zone (T1; T2).F2), which is guided in the light guidance channel (21), can exit the first shell (13) and enter the second shell (24; 25), and wherein the first reflective surface (26; 27) between the first and second shells (13; 23, 24) can be located on the section(s) on which the false light (F1; F2) propagating in the second shell (24; 25) can meet, which includes at least one first reflection zone (R1; R2, R3) and / or at least one first reflection area (RB1; RB2, RB3, RB4); exhibits such that the false light (F1 ; F2) is reflected at the section(s) and cannot re-enter the first shell (13).

2. Spectacle lens according to claim 1, wherein the at least one first transparency zone (T1 ; T2) is formed at least partially next to the at least one first reflection zone (R1 ; R2, R3) and / or at least partially next to the at least one first reflection area (RB1 ; RB2, RB3, RB4).

3. Spectacle lens according to claim 2, wherein the at least one first transparency zone (T1 ; T2) is formed both completely adjacent to the at least one first reflection zone (R1 ; R2, R3) and completely adjacent to the at least one first reflection area (RB1 ; RB2, RB3, RB4).

4. Spectacle lens according to one of the above claims, wherein the second shell (24; 25) has an absorber (31 ) onto which the false light (F1 ; F2) propagating in the second shell (24; 25) hits and is then absorbed by the absorber (31 ).

5. Spectacle lens according to one of the above claims, wherein the extent of each first transparency zone (T1 ; T2) in the first direction is less than the extent of the first reflective surface (26, 27) in the first direction.

6. Spectacle lens according to one of the above claims, wherein the extent of each first transparency zone (T1 ; T2) in the first direction is smaller than the extent of each first reflection zone (R1 ; R2, R3) in the first direction.

7. Spectacle lens according to one of the above claims, wherein the first reflective surface (26, 27) has exactly one first transparency zone (T1 ; T2) or exactly two first transparency zones (T1 ; T2).

8. Spectacle lens according to one of the above claims, wherein the at least one first transparency zone (T1 ; T2) has a higher transparency than the first reflective surface (26, 27).

9. Spectacle lens according to one of the above claims, wherein the at least one first transparency zone (T1 ; T2) has a transparency of greater than 90%.

10. Spectacle lens according to one of the above claims, wherein the spectacle lens (3) has a third shell (13; 24, 25), wherein the first and third shells (13; 24, 25) are connected to each other and a second reflective surface (26, 27) is formed between them, wherein the second reflective surface (26, 27) has at least one second reflective zone (R1; R2, R3) onto which the light beams (L1) of the generated image strike and are reflected when guided in the light guide channel (21), wherein the second reflective surface (26, 27) further comprises at least one second reflective area (RB1; RB2, RB3, RB4) which lies in the first direction next to the at least one second reflective zone (R1; R2, R3), wherein the second reflective surface (R1; R2, R3) has at least one second transparency zone (T1; T2) having, wherein unwanted false light (F1; F2), which is guided in the light guidance channel (21), can exit from the first shell (13) and enter the third shell (24; 25) via the at least one second transparency zone (T1; T2), and wherein the second reflective surface (26; 27) between the first and third shell (13; 23, 24) can be located at the section(s) on which the false light (F1; F2) propagating in the third shell (24; 25) can meet, the at least one second reflection zone (R1; R2, R3) and / or has at least one second reflection area (RB1 ; RB2, RB3, RB4) so ​​that the false light (F1 ; F2) is reflected at the section(s) and cannot re-enter the first shell (13).

11. Spectacle lens according to one of the above claims, wherein the first reflective surface (26, 27) and / or the second reflective surface (26, 27) is realized by a refractive index step which ensures total internal reflection.

12. Spectacle lens according to claim 10, wherein the refractive index jump is between the first shell (13) and a layer arranged between the first and second or third shell (13; 24, 25).

13. Spectacle lens according to claim 11 or 12, wherein the refractive index jump is between the first shell (13) and the second or third shell (24, 25).

14. Spectacle lens according to one of the above claims, wherein the first and / or second reflective surface (26, 27) is realized by an interference layer system.

15. Spectacle lens according to one of the above claims, wherein the first reflective surface (26, 27) and / or the second reflective surface (26, 27) is each designed as a continuous surface with the exception of the corresponding transparency zone (T1 ; T2).

16. Display device comprising a holding device (2) that can be placed on the head of a user, an image generation module (5) attached to the holding device (2) which generates an image, and a spectacle lens (3) attached to the holding device (2) according to one of the above claims, wherein the generated image is coupled into the first shell (13) via the entry section (28), guided in the first shell (13) by at least one reflection to the deflection section (18) and deflected at the first deflection section (18) to exit the spectacle lens (3) via the back (11), so that the user can perceive it as a virtual image when the holding device (2) is placed on the head.

Images