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
Patent Information
- Application Number
- EP2023748515
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-08-05
- Filing Date
- 2023-07-27
- Publication Date
- 2025-06-11
AI Technical Summary
Existing spectacle lenses for data glasses fail to consistently deliver high-quality images due to variations in optical design and assembly, particularly in series production, leading to undesirable image presentation.
A multi-shell spectacle lens design with reflective deflection elements and spacers ensures precise optical alignment, utilizing total internal reflection and reflective coatings to guide and deflect light bundles for improved image quality, and can be produced with high accuracy even in large quantities.
The solution provides a stable and high-quality image presentation by maintaining precise optical design parameters, enhancing image clarity and consistency, and allowing for customizable reflectivity and imaging functions, effectively addressing the issue of image quality variability in data glasses.
Smart Images
Figure 1.1
Abstract
Description
[0001] Spectacle lens for a display device that can be placed on the head of a user and generates an image, and display device with such a spectacle lens
[0002] The present invention relates to a spectacle lens for a display device that can be placed on the head of a user and generates an image, and to a display device comprising such a spectacle lens.
[0003] Such a lens is often used in so-called data glasses, where there is a constant need to improve the quality of the image presented to the user.
[0004] Based on this, it is the object of the invention to provide a spectacle lens which, when used in data glasses, improves the quality of the image presented to the user as much as possible.
[0005] The invention is defined in the independent claims. Advantageous further developments are specified in the dependent claims.
[0006] According to the invention, the spectacle lens for a display device that can be placed on the head of a user and generates an image comprises a front side, a back side, an entry section and a deflection section spaced from the entry section, as well as an exit section in the back side. Furthermore, the spectacle lens comprises a light guide channel that guides light beams of the generated image, which are coupled into the spectacle lens via the entry section of the spectacle lens, in the spectacle lens by means of at least one reflection (e.g., total internal reflection or reflection at a reflective layer) to the
[0007] deflection section, from which they are deflected towards the exit section and then decoupled from the spectacle lens through the exit section.
[0008] The spectacle lens can be constructed with multiple shells and comprise a first shell, a second shell, and a third shell, the second shell being arranged between the first and third shells and connected to the first and third shells. Furthermore, the second shell has a first interface facing the first shell and a second interface facing the third shell. The second shell has at least one first spacer projecting from the first interface and defining the distance between the second and first shells, and at least one second spacer projecting from the second interface and defining the distance between the second and third shells.
[0009] This ensures that the lens spacing specified by the optical design is maintained during lens manufacturing. This reliably prevents unwanted spacing variations, even in series production or high-volume production.
[0010] The deflection section can have several reflective deflection elements arranged side by side, which can realize a desired deflection function, e.g., in a Fresnel-like manner, and optionally a certain imaging function of the deflection section. The reflective deflection 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 (e.g., spherically or aspherically curved).
[0011] The reflectivity of the respective reflective deflection elements can, for example, be in the range of 2–100% (including the limits of the range). Thus, the reflective deflection elements can be partially reflective or reflective.
[0012] The spectacle lens can, in particular, have a curved rear side and / or a curved front side. The entrance section can be formed in the rear side. The curved rear side can be realized by the boundary surface of the third shell facing away from the second shell. The curved front side can be formed by the boundary surface of the first shell facing away from the second shell.
[0013] One or more coatings may be formed on the front and / or back.
[0014] The two facing interfaces of the respective shells can be bonded together with an adhesive layer (in particular, optical adhesive or optical cement). The thickness of the adhesive layer is determined by the protruding spacers and can be, for example, 30 μm to 1500 μm.
[0015] The spacers can be formed integrally with the second shell. The mutually facing interfaces of the first and second shells and / or the second and third shells can be curved.
[0016] Furthermore, a display device is provided comprising a holding device that can be placed on a user's head, an image generation module attached to the holding device that generates a (monochromatic or polychromatic) image, and a spectacle lens according to the invention attached to the holding device. By means of the spectacle lens, the generated image can be projected when the holding device is placed on the head in such a way that the user can perceive it as a virtual image.
[0017] The display device may include a control unit that controls the image generation module. In particular, the control unit may control the image generation module based on supplied image data.
[0018] The image generation module or the corresponding image generator unit can, in particular, comprise a planar image generator, such as an LCD module, an LCoS module, an OLED module, or a tilting mirror array. Each image generator can comprise a plurality of pixels, which can, for example, be arranged in rows and columns. Each image generator can, for example, be self-luminous or non-self-luminous.
[0019] Each imager can preferably generate a monochromatic image, with different imagers generating monochromatic images at different wavelengths. The image generation module can also be configured to generate a multicolor image.
[0020] The imaging module can thus 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 include an overlay unit that overlays the light beams of the multiple imagers into a single 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, both of which are known to those skilled in the art.
[0021] It is understood that the features mentioned above and those to be explained below can be used not only in the specified combinations, but also in other combinations or on their own, without departing from the scope of the present invention. The invention is explained in more detail below using exemplary embodiments with reference to the accompanying drawings, which likewise 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 exemplary 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 exemplary 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:
[0022] Fig. 1 is a schematic perspective view of an embodiment of the display device according to the invention;
[0023] Fig. 2 is an enlarged sectional view of the first spectacle lens including a schematic representation of the image generation module;
[0024] Fig. 3 is an enlarged schematic representation of the spectacle lens according to Fig. 2;
[0025] Fig. 4 is a schematic representation to explain the production of the intermediate shell according to Fig. 3;
[0026] Fig. 5 is an enlarged schematic representation of a modification of the spectacle lens according to Fig. 2, and
[0027] Fig. 6 is a schematic diagram to explain the production of the intermediate shell according to Fig. 5.
[0028] 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 pair of spectacle lenses 3, 4 which are fastened to the holding device 2. The holding device 2 with the spectacle lenses 3, 4 can be designed, for example, as safety goggles, sports goggles, sunglasses and / or spectacles for correcting ametropia, wherein a virtual image can be projected into the user's field of vision via the first spectacle lens 3, which is designed as a spectacle lens according to the invention and which can also be referred to as a multifunctional lens, as described below. For this purpose, the display device 1 comprises an 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.The image generation module 5 can have an image generation element 6 for generating a (monochrome or multicolor) image and an imaging optics system 7 arranged downstream of the image generation element 6 (Fig. 2). The image generation element 6 can be designed as a planar image generation element 6, e.g., as an OLED element, an LCD element, an LCoS element, or a tilting mirror matrix, each comprising a plurality 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 planar image generation element 6.
[0029] As can be further seen from Fig. 2, the image generation module 5 further comprises a control unit 8 with, for example, a processor P and a memory M for controlling the image generation module 5. The control unit 8 controls the image generation module 5 and in particular the image generation element 6 as a function of supplied image data such that the desired image is generated and thus corresponding light beams L1 are generated and enter the spectacle lens 3 via a curved rear side 9 of the spectacle lens 3. The entry area on the rear side 9 can also be referred to as the entry section 10.
[0030] The spectacle lens 3 further comprises a curved front side 11 and a deflection section 12 buried in the spectacle lens 3.
[0031] The deflection section 12 comprises a plurality of reflective deflection elements 14, which can also be referred to as first reflective facets. The reflectivity of the reflective deflection elements 14 can, for example, be in the range of 2-100%.
[0032] Furthermore, Fig. 2 schematically shows that the spectacle lens 3 is designed as a multi-layered structure comprising an outer shell 15, an inner shell 16, and an intermediate shell 17 arranged therebetween. The mutually facing interfaces of the outer and intermediate shells 15, 17, as well as the intermediate and inner shells 17, 16, are bonded with an adhesive. The outer shell 15 can also be referred to as the first shell 15, the intermediate shell 17 can also be referred to as the second shell 17, and the inner shell 16 can also be referred to as the third shell 16.
[0033] As already described, the light beams L1 enter the spectacle lens 3 via the entrance section 10 in the rear side 9. The light beams L1 are then guided in the spectacle lens 3, e.g. by total internal reflection at the rear side 9 and reflection in the intermediate shell 17, up to the deflection section 12, so that a light guide channel 18 is present from the entrance section 10 to the deflection section 12. The deflection section 12 then deflects the light beams L1 towards the rear side 9 in such a way that the deflected light beams L1 exit the spectacle lens 3 via the rear side 9. The area through which the light beams L1 exit can also be referred to as the exit section 19.
[0034] Fig. 3 shows a part of the right-hand spectacle lens 3 in an enlarged schematic representation. As can be clearly seen, the intermediate shell 17 has a first interface 20 facing the outer shell 15 and a second interface 21 facing the inner shell 16. Two first raised structures 22i and 222, which serve as first spacers, are formed on the first interface 20. The interface 23 of the outer shell 15 facing the intermediate shell 17 thus rests on the first spacers 22i and 222, which protrude from the first interface 20 by, for example, 30 pm to 1500 pm, thereby defining the distance between the outer shell 15 and the intermediate shell 17. The two shells 15 and 17 are preferably adhesively bonded to one another so that the distance predetermined by the first spacers 22i and 222 is maintained during the adhesive bonding (or joining) process. It can, for example,an adhesive 24 may be used whose refractive index is matched to that of the base material of the intermediate and outer shells 17, 15. In this case, a reflective coating may be provided on the first interface 20 in the region of the light guide channel 18 in order to achieve the desired reflections at the first interface 20. If no reflective coating is provided, total internal reflection at the front side 11 may also be used to guide the light (not shown). Alternatively, the refractive index of the adhesive 24 and, if applicable, of the outer shell 15 may be selected such that total internal reflection occurs at the first interface 20 or at the interface 23 of the outer shell 15 facing the intermediate shell 17.
[0035] At the second interface 21, two second raised structures 25i and 252 are formed, which serve as second spacers. The interface 26 of the inner shell 16 facing the intermediate shell 17 rests on the second spacers 25i and 252, which protrude from the second interface 21 by, for example, 30 pm to 1500 pm, so that the distance between the inner shell 16 and the intermediate shell 17 is thereby determined. The two shells 16 and 17 are preferably adhesively bonded to one another, so that the distance predetermined by the second spacers 251 and 252 is maintained during the adhesive bonding (or joining). For example, an adhesive 27 can be used whose refractive index is matched to that of the base material of the intermediate and inner shells 17, 16. In this way, total internal reflection on the rear side 9 can be used to ensure the light guidance.
[0036] The image generation module 5 and the spectacle lens 3 are designed such that a user wearing the display device 1 according to the invention on their head can perceive the image generated by the image generation module 5 as a virtual image. Depending on the reflectivity of the deflection elements 14, the virtual image can be perceived by the user as superimposed on the surroundings. With very high reflectivity, and in particular with a reflectivity of 100%, the user can only perceive the virtual image and not the surroundings, at least in the region of the deflection section 12, unless the deflection elements 14 are spaced so far apart that ambient light still reaches the viewer's eye between the individual deflection elements 14 of the deflection section 12, allowing the viewer to perceive the surroundings.
[0037] An advantageous method of manufacturing the intermediate shell 17 can be achieved, for example, by forming or, for example, by injection molding with a corresponding mold 30, as schematically shown in Fig. 4. In this way, the intermediate shell 17 with the raised spacers 22i and 222 as well as 25i and 252 can be manufactured with the desired accuracy (even in high quantities).
[0038] Fig. 5 shows a modification of the spectacle lens 3 according to the invention, and in particular of the intermediate shell 17. In this modification, additional second spacers 25s and 254 are provided, which are formed in the finished spectacle lens 3 close to the reflective deflection elements 14. A corresponding mold 31 for producing the intermediate shell 17 according to Fig. 5 is shown in Fig. 6.
[0039] The display device 1 can also be designed such that the left spectacle lens 4 is configured as a multifunctional lens in the manner described in connection with Figures 1 to 6. In this case, the image generation module 5 is preferably arranged in the region of the left temple. Furthermore, it is possible for both the left spectacle lens 4 and the right spectacle lens 3 to be configured as multifunctional lenses, with a separate image generation module 5 preferably being arranged for each spectacle lens 3, 4 (preferably in the left and right temples).
[0040] The deflection section 12 can provide pure beam deflection. Preferably, it can also provide an imaging effect.
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 (11) and a rear side (9), an entry section (10) and a deflection section (12) spaced from the entry section (10), an exit section (19) in the rear side (9), and a light guide channel (18) that guides light beams (L1) of the generated image, which are coupled into the spectacle lens (3) via the entry section (10) of the spectacle lens (3), in the spectacle lens (3) by means of at least one reflection to the deflection section (12), from which they are deflected in the direction of the exit section (19) and then coupled out of the spectacle lens (3) through the exit section (19), wherein the spectacle lens (3) has a multi-shell construction and has a first shell (15), a second shell (17), and a third shell (16), wherein the second shell (17) between the first and third shell (15,16) and is connected to the first and third shells (15, 16), wherein the second shell (17) has a first interface (20) facing the first shell (15) and a second interface (21) facing the third shell (16), wherein the second shell (17) has at least one first spacer (22i, 22z) which projects relative to the first interface (20) and defines the distance between the second and first shells (15, 17), and at least one second spacer (25i, 252, 25s, 254) which projects relative to the second interface (21) and defines the distance between the second and third shells (17, 16).
2. Spectacle lens according to claim 1, wherein the at least one first spacer (22i, 222) and the at least one second spacer (25i, 252, 25s, 254) are formed integrally with the second shell (17).
3. Spectacle lens according to claim 1 or 2, wherein the first and third shells (15, 16) are formed free of spacers.
4. Spectacle lens according to one of the above claims, in which the first and second shells (15, 17) are connected by means of a first adhesive layer (24) and the second and third shells (17, 16) are connected by means of a second adhesive layer (27).
5. Spectacle lens according to one of the above claims, wherein the deflection section (12) is formed in the third shell (16).
6. Spectacle lens according to one of the above claims, wherein the deflection section (12) has a plurality of reflective deflection elements (14) arranged next to one another.
7. Spectacle lens according to claim 6, wherein a structure defining the geometric dimensions for the reflective deflecting elements (14) is formed integrally with the third shell (16).
8. Spectacle lens according to one of the above claims, wherein the light guide channel (18) is formed in the second and third shell (16, 17).
9. Spectacle lens according to one of the above claims, in which the two boundary surfaces (20, 21) are curved.
10. 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 (3) and generates an image, and a spectacle lens (3, 4) according to one of the above claims that is fastened to the holding device (2) and that displays the generated image when the holding device (2) is placed on the head in such a way that the user can perceive it as a virtual image.