Optical arrangement having an optical waveguide for radiating-in virtual images, and head-mounted display

Abstract

The invention relates to an optical arrangement (1) which comprises an optical waveguide (2) for radiating-in images which can be perceived as virtual images, and to a fastening apparatus (6) for fastening the optical arrangement (1) to the head of a person; wherein the fastening apparatus (6) comprises a coupling-out region (7) for arranging a projector (12); wherein the optical waveguide comprises a coupling-in region (9). The optical arrangement (1) comprises a further optical waveguide (3) having a coupling-in device (5) and a coupling-out device (4); wherein the further optical waveguide (3) is arranged in the beam path between the coupling-out region (7) of the fastening apparatus (6) and the coupling-in region (9) of the optical waveguide (2).

Description

[0001] Optical arrangement with fiber optic cable for irradiating virtual images and head-mounted display

[0002] The present invention relates to an optical assembly that can be worn in front of the eyes and a head-mounted display.

[0003] Head-mounted displays (HMDs), for example in the form of data glasses or AR headsets (AR - Augmented Reality) or VR headsets (VR - Virtual Reality) or MR headsets (MR - Mixed Reality) or AR or VR or MR glasses or VR or MR helmets, are used in numerous contexts. In these cases, the light waves used to generate a virtual image are usually guided by total internal reflection after being coupled into an optical fiber to an output. When a user looks through a head-mounted display, e.g. "augmented reality glasses" or "AR glasses" for short, they see a coupled-in or reflected "virtual image" superimposed on their image of the real world ("real image").This superposition is achieved by the optical fiber, also called a beam combiner, which is transparent to the ambient light and also directs a beam of rays generated by an external imager into an eyebox, which can contain the user's eye. The eye perceives this beam of rays as a virtual image. To describe the beam path of the image of the real environment and the coupled virtual image, an imaging path can be defined. An imaging path is understood to be the path of the light from the object, e.g. an object in the real environment, or from the imager / projector that emits the virtual image to be coupled in, to the location where the image is created or perceived, e.g. the user's eye or the eyebox.In augmented reality (AR), the environment visible to a user is enhanced by adding digital elements to a live view of the environment, i.e., a mapping path of the real environment. In virtual reality (VR), users only perceive virtual images. Thus, the mapping path of a real environment is replaced by a mapping path of a virtual environment (simulated environment).

[0004] In a head-mounted display, e.g. in AR headsets, the image generated by an imaging unit or a display is coupled into the optical fiber, reflected once or several times within the optical fiber by total internal reflection, and finally coupled out so that a user of the head-mounted display can see a virtual image. The spatial area from which the virtual image is visually perceptible to a user is also referred to as the eyebox. The two outer surfaces of the optical fiber are often designed as parallel flat surfaces so that neither optical refractive power is introduced within the optical fiber, nor are aberrations that impair image quality created. Furthermore, head-mounted displays, e.g. AR headsets, can comprise an optical fiber and one or more additional lenses (push-pull lens principle) per eye.This one lens or these several additional lenses serve to correct the ametropia (refractive error) or presbyopia (age-related farsightedness) of the eye (pull lens) and / or to make the virtual image appear focused at a desired distance (pull lens) without impairing the image of the real environment (push lens).

[0005] The state of the art regarding near-eye displays and head-mounted displays is described, for example, in documents CN 1 14 415 228 A and CN 1 15 702 313 A.

[0006] Currently, standard solutions are marketed for glasses that enable the playback or projection of virtual content, e.g. images. This means that only a single size is offered (one size fits all / most). This applies, for example, to AR glasses (AR - Augmented Reality), but also VR glasses (VR - Virtual Reality) and MR glasses (MR - Mixed Reality). The coupling position of the imaging light is specified accordingly, and a suitable frame is developed. With reflective coupling elements, the pupil size, i.e. the exit pupil of the projector, which usually corresponds to the pupil of the eye, as well as the coupling angle and thus the size of the light cone to be coupled, determine the thickness of the optical fiber used for coupling when the pupil lies on the coupling element, e.g. the coupling mirror.

[0007] Currently, one-size-fits-all / most solutions are marketed for AR glasses. This limits the choice of frames, or rather, frames are developed for specific waveguides. The frames and waveguides are larger and heavier than necessary for an individual user or specific user groups (excluding the group of most or all users). When manufacturing and designing such glasses, attempts are made to minimize the size of the optical fiber and to individualize its contour or to make it compatible with as many conventionally sized frames as possible. In the extreme case of waveguide size minimization, the position of the pupil coupling into the optical fiber, e.g., the AR waveguide, is predetermined by the size adjustment and is no longer coincident with the frame-dependent projector coupling position.Although the size of the optical fiber fits into most sockets, the light may no longer be able to be coupled into the optical fiber on a socket-by-socket basis.

[0008] Typically, a planar waveguide, for example, for AR systems, is designed so that the pupil coupling is located near the temple of a pair of glasses, the nose bridge, or along the outer contour. However, a fully minimized AR optical waveguide typically has a contour where the position of the pupil coupling is not in the desired coupling area, e.g., near the temple of a pair of glasses, the nose bridge, or along the outer contour.

[0009] Against this background, the object of the present invention is to provide an advantageous optical arrangement and a head-mounted display that mitigates the disadvantages of the previously described solutions. These objects are achieved by an optical arrangement according to claim 1 and a head-mounted display according to claim 16. The dependent claims contain further advantageous embodiments of the invention.

[0010] The optical arrangement according to the invention, which is preferably wearable in front of the eyes or is generally designed as a head-mounted display, comprises an optical waveguide for projecting or playing back images that are perceivable as virtual images (virtual content). The optical arrangement further comprises a fastening device for attaching the optical arrangement to a person's head. The fastening device can be designed, for example, as a bracket, in particular as a nose bridge or nosepiece or earpiece. The fastening device, for example the bracket, comprises an output coupling region for arranging a projector.The coupling-out region can be formed by a region of the fastening device in which light is coupled out by a projector, i.e., a coupling-out region of a projector can be arranged, or in other words, a region in which the light beam containing the image leaves the projector. Optionally, the optical arrangement can comprise a projector with a coupling-out region, wherein the coupling-out region is arranged in the region or on the fastening device. The optical waveguide has a coupling-in region, in particular a pupil coupling-in region. The coupling-in region can comprise coupling optics.

[0011] The optical arrangement also comprises a further optical waveguide with a coupling device and a coupling device, wherein the further optical waveguide, in particular for transmitting the pupil coupling, is arranged in the beam path between the coupling-out region of the fastening device and the coupling-in region of the optical waveguide, i.e. the first-mentioned optical waveguide for radiating the virtual images towards the eye.

[0012] In an advantageous variant, the optical fiber, i.e. in other words the first optical fiber, is designed as a size-minimized optical fiber, and the further optical fiber, i.e. in other words the second optical fiber, is designed as a length- and / or rotation-angle-corrected further optical fiber. The length- and / or rotation-angle-corrected further optical fiber can be arranged displaceably within a frame contour of the fastening device, in particular within a spectacle lens frame contour, and thus enable individual adaptation. The individual design of both the size-minimized optical fiber and the length- and / or rotation-angle-corrected further optical fiber can be based on a simulation and / or optimization of the respective optical fiber design. In this context, one or more customization parameters can be used.

[0013] The present invention has the advantage of offering a highly customizable optical arrangement, e.g., in the form of an HMD. Using the additional optical fiber, which forms an intermediate link between the projector and the optical fiber for radiating light waves toward the eye, it is possible to combine both a customized and minimized-size optical fiber with a customized frame, for example, with a customized contour. This provides additional degrees of freedom in the design and technical configuration of corresponding glasses, such as AR glasses. Overall, this significantly improves user acceptance and comfort compared to previously known solutions.

[0014] For example, the described additional optical fiber can be geometrically and functionally designed to adapt to the expected bridging distances and bridging angles. However, a set of additional optical fibers can also be provided, with each individual optical fiber designed for specific bridging distances and bridging angles. These variants enable a simple and cost-effective adaptation of a customized optical fiber for a pair of glasses to a customized eyeglass frame.

[0015] In an advantageous embodiment, the coupling-out region of the fastening device can be connected or connected, e.g., directly connectable or connected, to the coupling device of the additional optical fiber (hereinafter also referred to as the bridging optical fiber). The coupling-out device of the additional optical fiber can be connected or connected, e.g., directly connectable or connected, to the coupling-in region of the optical fiber, i.e., the optical fiber for radiating light waves toward the eye (hereinafter also referred to as the AR optical fiber).

[0016] Preferably, the further optical waveguide is configured as a periscope optical waveguide. In the context of the present invention, a periscope optical waveguide is understood to mean an optical waveguide that effects a stepped beam offset between the coupled-in and coupled-out light. The coupled-in light beams and the coupled-out light beams can, for example, run parallel to one another, particularly with respect to the respective main beams. Alternatively, the coupled-in light beams and the coupled-out light beams can enclose an angle that is less than 90°, preferably less than 45°.

[0017] The coupling device and / or the coupling device of the further optical waveguide can be refractive and / or diffractive and / or reflective and / or transmissive and / or comprise at least one holographic optical arrangement. The optical waveguide (AR optical waveguide) and / or the further optical waveguide (bridging optical waveguide) can be customized, i.e., adapted to a specific person, according to at least one specified customization parameter. The at least one customization parameter can be an interpupillary distance, i.e., the interpupillary distance of a person, and / or a head width, i.e., the head width of a person, and / or at least one geometric parameter of a spectacle frame, and / or a position of the coupling region of the optical waveguide, and / or a position of the coupling region, e.g., of the temple and / or the projector.The at least one individualization parameter can also be the length of the further optical waveguide, e.g. in a sagittal direction, or another geometric parameter and / or the position of the further optical waveguide relative to the optical waveguide (AR optical waveguide) and / or a rotation angle, e.g. an azimuthal rotation angle, of the further optical waveguide (bridging optical waveguide) relative to the optical waveguide (AR optical waveguide).

[0018] The optical fiber (AR optical fiber) and / or the additional optical fiber (bridging optical fiber) can be constructed from segments, i.e., have a segmented design. The individual segments are arranged adjacent to one another, next to one another, or directly adjacent to one another in a plane perpendicular to the line of sight of a user through a spectacle lens encompassing the optical fiber, or in a plane spanned by the extension of the optical fiber. A segmented design is advantageous for simple and cost-effective production. The joints between the individual segments can be index-adjusted, e.g., by gluing.

[0019] In a further variant, the optical arrangement comprises a spectacle frame with a frame contour, and the additional optical waveguide is arranged displaceably within the frame contour. This enables flexible adaptation of a customized optical waveguide (AR optical waveguide) to a predetermined frame contour of the spectacle frame. The additional optical waveguide can be designed as a planar optical waveguide. Preferably, the additional optical waveguide is designed for optical waveguide in a sagittal direction, i.e., along a longitudinal axis.

[0020] Advantageously, a rotation angle of a longitudinal axis of the further optical fiber, e.g. the azimuthal rotation angle, relative to a specified coupling point in the optical fiber, and a rotation angle, e.g. the azimuthal rotation angle, of an image to be coupled in relative to a specified coupling point in the further optical fiber have the same magnitude and the same direction. For example, an optical device can be arranged in the beam path between a projector and the coupling device of the further optical fiber, which causes a complete image inversion without beam offset. This can be achieved, for example, by means of an azimuthally rotatable Schmidt-Pechan prism or by means of at least two mirrors. The variants mentioned ensure correct image transmission despite the adaptation of the beam path using the further optical fiber.

[0021] In an advantageous variant, the optical arrangement comprises a projector that is arranged and / or adjusted such that the exit pupil of the projector lies on the coupling area, e.g., a corresponding coupling optic, of the optical fiber (AR optical fiber), i.e., coincides with the optical fiber entrance pupil. This ensures correct coupling into the optical fiber. Alternatively, the exit pupil of the projector can also be located in the additional optical fiber. This allows the thickness and weight of the optical fiber to be significantly reduced. Furthermore, the pupil position becomes accessible independently of a mirror, for example, for stray light optimization (see Lyot aperture).

[0022] The optical arrangement can further comprise a projector that is axially displaceable along the fastening device, e.g., along a spectacle frame. This displaceability allows for individual adjustment of the exit pupil position of the projector and thus a correct adaptation of this to the fiber optic entrance pupil.

[0023] In a further variant, the optical arrangement comprises an optical device arranged in the beam path between the projector and the additional optical fiber, which is designed to adjust the exit pupil position of the projector, in particular for individual adjustment for a specific person. The optical device can be, for example, a zoom lens or an optical relay system.

[0024] The optical arrangement can comprise an optical device for correcting an angle of the fastening device, e.g., a temple, with respect to the coupling device of the further optical waveguide, wherein the optical device is arranged between the coupling-out region of the projector and the coupling device of the further optical waveguide. The optical device can comprise a compensation wedge, in particular in the form of a prism, and / or at least two reflective optical elements, e.g., mirrors. By means of the optical device, individually different angles between the spectacle frame and the temples can be individually corrected, i.e., individually adapted to the anatomy of the respective person.

[0025] In an advantageous variant, the optical arrangement comprises at least one lens, e.g., a push and / or pull lens. The at least one lens advantageously comprises a cutout or recess adapted to the geometry of the further optical waveguide. Additionally or alternatively, the refractive index and / or the refractive index dispersion of the further optical waveguide can be adapted to the refractive index and / or the refractive index dispersion of the at least one lens and / or to a boundary layer, e.g., air and / or adhesive, arranged between the further optical waveguide and the lens. The head-mounted display according to the invention comprises an optical arrangement according to the invention as described above. It has the same features and advantages as the optical arrangement according to the invention.

[0026] In principle, the optical arrangement according to the invention and / or the head-mounted display according to the invention can be designed as AR glasses or MR glasses or VR glasses or a corresponding helmet.

[0027] The following describes how an individualized and / or size-minimized optical waveguide can be produced. A corresponding optical waveguide, in particular an individualized and / or size-minimized optical waveguide produced as described below and in the context of the exemplary embodiments, can be a component of the optical arrangement according to the invention. The term "individualized optical waveguide" is understood to mean an optical waveguide which is adapted to a group of people or users defined by at least one specified parameter or parameter range, or to a specific person, with regard to at least one degree of design freedom. The degree of design freedom can be, for example, the geometric configuration of the optical waveguide and / or the position and / or size of an output coupling region, etc.The term "size-minimized optical fiber" refers here to an optical fiber whose dimensions are adapted to a group of people or users defined by at least one specified parameter or parameter range, or to a specific person, in such a way that at least one, preferably several, variables determining the dimensions of the optical fiber are minimized. For example, the length and / or width of the optical fiber can be minimized relative to a specified coordinate system, or the total volume and thus the weight of the optical fiber can be minimized. In particular, the coupling region and / or the pupil replication region and / or the coupling-out region of the optical fiber can be minimized.To create a customized and / or minimized-size optical waveguide, an optical waveguide, including the input and output coupling device and two-dimensional pupil replication, is designed to be minimally sized for an individual or a group of individuals and supplemented by a sufficiently large wafer area, e.g., a substrate in the form of a disk. This wafer, i.e., a semi-finished product enclosing the optical waveguide, can be cut out for any spectacle frame and / or any eye position. With a customized cutout, the input and output coupling areas, as well as the pupil replication area, can be designed to be minimally sized, as described below.

[0028] In addition to specific customization for a user or frame model, the input and output coupling and pupil replication ranges can be moderately expanded for specific user groups, for example, for user groups with interpupillary distances of 49 to 58 mm, 58 mm to 67 mm, or 67 mm to 76 mm. Other ranges are of course possible. In this case, several semi-finished product variants are defined (wafers with optical fiber regions), for example, three variants, which are selected according to the respective user requirements and cut to size for each frame and / or user.

[0029] The optical fiber with input and output coupling as well as pupil replication elements, for example with semi-transparent mirrors, is minimized in size based on a desired field of view of a virtual image and position tolerances of the optical system relative to the user.Parameters for defining individual user groups or for individualization for a person can be, in particular, the meridional eye distance range and / or the distance range of the waveguide to the eye along the line of sight to the center of the virtual image and / or the angular orientation of the waveguide to lines of sight of the image content (for example the line of sight to the center of the image) and / or the size of the eye pupils and / or the field of view and the respective fields of view for the virtual image and the viewing and / or the distance from the eye pupil to the focal plane of the virtual image and / or the waveguide material and / or the position of the coupling of the image information of an image collimator.

[0030] To derive the position tolerances of a spectacle frame, slippage on a representative nose bridge can be simulated. The underlying spectacle frame can be a commercially available model from an optician's shop. Lenses can be attached to the front and back of the optical fiber, so-called push and pull lenses. These define the focal plane for the virtual image (e.g. 1 m) and are used to correct possible visual defects. For the viewing angle of the eye by rotating the eyeball, a range of ±17.5° around a viewing direction can be assumed, whereby the viewing direction can be oriented by -2.5° downwards relative to the meridional plane. In addition, an axially symmetric field of view of ±30° can be assumed, i.e. a range in which symbols can usually still be perceived in the peripheral vision.

[0031] Within the gaze cone, the eye is oriented, for example, such that the line of sight is directed to the center of a virtual image one meter away along the line of sight from the pupil center, which is tilted by -10° around the meridional plane. A field of view of, for example, ±17.7° can be constructed around this line of sight to the image center. The intersection of this field with the back of the fiber optic cable, the so-called "output footprint," can be used to identify the area from which light is coupled out toward the eye. The specification can be a square virtual image with image corners at a field of view of ±25° from the line of sight to the image center.

[0032] Based on this, a volume can be spanned which contains all viewing directions with a filled pupil and indicates the area in which the pupil moves. For this purpose, two orthogonal elevation angles of an eye model used can be adjusted using optimization so that the eye model looks into the corners of the image. The area spanned by the pupil center movement is ideally spherical and depends, among other things, on the distance of the eye from the optical fiber. Together with this distance variation along the line of sight, the so-called "eye box" is created, i.e. a spatial area in which the pupil is located for all relevant variations, in particular with variable angular orientation according to the eye rotation. In addition to this variation, there are position tolerances for the described optical system relative to the pupil or the eye box.These include, for example, a possible slippage of the glasses on the bridge of the nose downwards, e.g. 4 mm, or upwards, e.g. 1 mm, a lateral tolerance of the attachment of the optical system within the frame, e.g. ± 1 mm, as well as measurement tolerances for the interpupillary distance, e.g. ± 1 mm.

[0033] For the variations described, footprints can be recorded using a semi-automated or automated analysis process, and an integrated quadrangular footprint can be generated from them. This is usually no longer exactly square. The same applies to the eye box. The footprint integrated across all relevant variations specifies the required minimum area for coupling, which is independent of the selected fiber optic technology, for example, independent of the design as diffractive or reflective couplers and pupil replicators.

[0034] Based on the integrated footprint, a reference geometry can be defined, which consists of reference coordinate systems, planes, axes and points, as well as reference curves. With the reference geometry, for the application of reflective pupil replication, as well as coupling and decoupling, by specifying the fiber optic material (e.g., N-LASF46B glass from SCHOTT), the eye pupil size to be filled (e.g., 1.5 mm diameter), the desired angular pitch of the

[0035] Pupil replication (e.g., 1°), the minimum lateral extent of the angular pitch (e.g., 1 mm to 1.5 mm), and the desired coupling position of the image information, e.g., near the temple of the eyeglass, the parameters for a minimally sized optical fiber are automatically determined in an optimization process. This fiber optic cable couples the coupled light toward the eye with a homogeneous radiation intensity (unit [W / sr]). The described reference geometry is necessary for a homogeneous distribution and coupling of the light, whereby the virtual image appears the same in color and brightness for visual perception, even with the described variances.

[0036] The optical design can be sufficiently defined by specifically designed semi-transparent mirrors. The geometric parameters that can be automatically optimized are the light propagation volumes within the optical fiber, the number and position of the semi-transparent mirrors, the thickness of the optical fiber, and the geometry of the blanks from which the wafer-shaped semi-finished product is constructed. The elevation angles of the coupling and decoupling devices are designed based on the line of sight to the image center, the pantoscopic angle, and the wrap angle (the angle of inclination of the lens to the sagittal plane). This can be done directly within the geometric model or with the help of a coupled optical simulation.

[0037] Depending on the azimuthal position of the reference geometry, for example, the footprint width and / or the coupling position of the image collimator, the fiber optic volume can be automatically limited by condition-controlled cuts along the footprint dimensions. This avoids unnecessary fiber optic sections that are unfavorable in terms of volume and optical properties, such as stray light. The required reflectances and transmittances of the semi-transparent mirrors can also be determined automatically. They depend, among other things, on the number of mirrors, which can be automatically varied during geometry optimization. The aforementioned fundamental radiometric properties of the respective mirrors are important for a coupled non-sequential optics simulation, with which all of the parameters described above can be finely optimized.In particular, this involves multi-objective optimization with regard to volume minimization and optical performance, for example, geometry adaptation to reduce tolerances and stray light, but can also include coupling to structural mechanics simulations, for example, to desensitize the optical system to temperature variations and other mechanical load cases. The partially transparent mirrors can be realized, for example, using dielectric multi-layer coatings or holographic optical elements (HOEs).

[0038] For attaching the image collimator to the optical fiber and aligning it along the temple of a spectacle frame, a corresponding optical assembly can be provided, which can itself be designed as an optical fiber. Through appropriate optical design, the optical assembly can decouple the alignment of the image collimator along the temple and the required incoming direction of the main ray at the image center. This optical assembly can be important as a boundary condition for system optimization.

[0039] The segments from which the wafer-shaped semi-finished product described above is constructed can be joined together using conventional methods, for example, by gluing or anodic bonding. Individual contour cutting can be performed using conventional separation processes, such as cutting or cleaving with ultrashort pulse lasers.

[0040] The described optical design process produces a minimized optical waveguide that can be integrated into a wafer-shaped semi-finished product. This semi-finished product can be customized to a specific frame shape and / or target audience. The optical design can be performed in CREO Parametric, for example. Parametrically coupled optical simulations and fine optimizations can be performed using ZEMAX, for example.

[0041] The section of the optical fiber that provides the virtual image for the AR optical system is individually adaptable, e.g., for different frames and / or user characteristics, such as head width and interpupillary distance, although the underlying optical fiber for the virtual image, including input and output coupling and the pupil replication areas, remains geometrically the same or only needs to be available in a few variants. For example, variants can be provided for three interpupillary distance ranges and, if necessary, further variants for ranges of pantoscope angles and wrap angles, for a total of, for example, twelve variants. This is particularly advantageous for customizing the optical system in large-scale production.

[0042] The described method enables a minimized optical waveguide including coupling and decoupling areas, which can be inserted into a sufficiently large wafer and can be individually cut out of it. The optical waveguide coupling areas and / or the

[0043] Optical fiber output regions and / or pupil replicators can be designed as diffractive or reflective. The optical fiber material can be made of glass or plastic. The outer contour of the wafer-shaped semi-finished product is ideally selected to minimize waste during cutting, particularly to reduce costs and waste, for example, with a polygonal base (e.g., an equilateral hexagon).

[0044] By minimizing the size of the optical fiber, especially the coupling area, the pupil replication area, and the output area, the eyeglass size can be reduced to the necessary size and no longer has to fit everyone—it is made to fit. This makes the optical system lighter, which is a key requirement for AR / VR / MR systems. The customized cutout allows one optical fiber design, or a few optical fiber design variants, to be used for many different frames and users. This enables cost savings and contributes to suitability for large-scale production.

[0045] The invention will be explained in more detail below using exemplary embodiments with reference to the accompanying figures. Although the invention is illustrated and described in more detail by the preferred embodiments, the invention is not limited to the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention.

[0046] The figures are not necessarily detailed or to scale and may be enlarged or reduced to provide a better overview. Therefore, the functional details disclosed herein are not to be interpreted in a limiting sense, but merely as an illustrative basis for teaching one skilled in the art how to variously employ the present invention.

[0047] As used herein, the term "and / or," when used in a series of two or more elements, means that any of the listed elements may be used alone, or any combination of two or more of the listed elements may be used. For example, if a composition is described containing components A, B, and / or C, the composition may contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.

[0048] Fig. 1 shows schematically an optical arrangement according to the invention in three variants.

[0049] Fig. 2 shows a schematic view of a lens of AR glasses with a conventional pupil coupling position of the optical waveguide.

[0050] Fig. 3 shows a schematic view of a lens of AR glasses with a completely minimized optical waveguide.

[0051] Fig. 4 shows schematically an optical arrangement according to the invention, which comprises the spectacle lens shown in Fig. 3.

[0052] Fig. 5 shows a schematic perspective view of another optical waveguide. Fig. 6 schematically shows a rotation of the additional optical waveguide relative to the coupling region of the optical waveguide and the associated rotation of the projector image.

[0053] Fig. 7 shows schematically the adjustment of the pupil position depending on the length of the further optical fiber.

[0054] Fig. 8 shows schematically a Schmidt-Pechan prism and its

[0055] Application for compensating image rotation.

[0056] Fig. 9 shows schematically further examples for correcting an oblique coupling angle.

[0057] Fig. 10 shows schematically a bracket angle correction using mirrors.

[0058] Fig. 11 shows schematically another optical waveguide with central

[0059] Pupil position.

[0060] Fig. 12 shows schematically a perspective view of a beam path through an optical arrangement according to the invention at an azimuthal rotation angle of the further optical waveguide of 145 degrees.

[0061] Fig. 13 shows schematically a perspective view of a beam path through an optical arrangement according to the invention at an azimuthal rotation angle of the further optical waveguide of 130 degrees.

[0062] Fig. 14 schematically shows a perspective view of a beam path through an optical arrangement according to the invention with an azimuthal rotation angle of the further optical waveguide of 115 degrees. Fig. 15 schematically shows a view of the beam path shown in Figure 14 through an optical arrangement according to the invention in a yz plane.

[0063] Fig. 16 shows a schematic view of the beam path shown in Fig. 14 through an optical arrangement according to the invention in an xy plane.

[0064] Fig. 17 shows schematically a view of the beam path shown in Fig. 14 through an optical arrangement according to the invention in an xz plane.

[0065] Fig. 18 shows schematically a semi-finished product in the form of a wafer with a size-minimized optical waveguide.

[0066] Fig. 19 shows schematically a wafer constructed from segments.

[0067] Fig. 20 shows schematically a section of the wafer shown in Fig. 19.

[0068] Fig. 21 shows schematically a semi-finished product in the form of a wafer with a non-individualized optical waveguide.

[0069] Fig. 22 shows schematically a semi-finished product in the form of a wafer with a size-minimized optical waveguide.

[0070] Fig. 23 shows schematically a semi-finished product in the form of a wafer with three variants of size-minimized optical waveguides.

[0071] Fig. 24-29 schematically show a spectacle lens with an optical waveguide and the geometric parameters used in a simulation to minimize the size of the optical waveguide. Figure 1 schematically shows an optical arrangement 1 according to the invention using the example of an AR spectacle lens in three variants. The spectacle lens 28 shown is arranged in a frame 8 with a fastening device 6, e.g., a temple piece, and comprises an optical waveguide 2 with a coupling region or coupling device 9 for coupling light rays from a projector (not shown) into the optical waveguide 2 and a coupling region 19 for coupling light rays out of the optical waveguide 2 in the direction of an eyebox or an eye of a person.In the three variants shown, the optical waveguide 2 is adapted to a specific person in terms of its position, i.e., the position of the output coupling device 19 and thus also the position of the input coupling region 9, on or in the spectacle lens 28. An output coupling region 7 for arranging the projector is arranged in the area of ​​the fastening device 6.

[0072] To bridge the respective distance between the outcoupling region 7 and the coupling region 9, the optical arrangement 1 has a further optical waveguide 3 with a coupling device 5, which is arranged at the outcoupling region 7, and a coupling device 4, which is arranged at the coupling region 9. The further optical waveguide 3 is therefore arranged in the beam path between the outcoupling region 7 of the fastening device 6 and the coupling region 9 of the optical waveguide 2. In the variants shown, the further optical waveguide 3 has an adapted length and an adapted angle of rotation with respect to the coupling region 9 of the optical waveguide 2. The optical arrangement according to the invention thus enables the fitting of an individualized, in particular size-minimized optical waveguide into any spectacle lens frame.

[0073] Figure 2 schematically shows a lens 28 of AR glasses, for example, a wafer comprising the optical waveguide with at least one push and / or pull lens bonded thereto, with a conventional pupil coupling position 9, i.e., a conventional position of the coupling region 9 of the optical waveguide 2 at the position of a conventional output region 7 of the projector. Typically, a planar optical waveguide 2 for AR systems is designed such that the pupil coupling 9 is located in the region of a temple piece 6, the nose bridge, or along the outer contour 8 of the wafer for a frame. However, a fully minimized AR optical waveguide 2 is more likely to have the exemplary contour shown in Figure 3. This optical waveguide contour is customized according to the individualization parameters, such as interpupillary distance, specific frame, and head width, etc., is shifted within the frame contour, and the virtual image is transported to the coupling position 9 of the AR optical waveguide 2 via an additional, for example individually adapted, optical waveguide 3, which can be designed as a periscope optical waveguide. This is shown in Figure 4. Figure 4 thus shows an optical arrangement according to the invention in the form of an AR spectacle lens as part of a head-mounted display according to the invention in the form of AR glasses. In other words, the resulting distance between the coupling-out region of the projector (not shown) of the AR glasses in the region of the fastening device 6 is bridged by means of the additional optical waveguide 3 within the framework of an optical arrangement 1 according to the invention.

[0074] Figure 5 schematically shows a perspective view of another optical waveguide 3. The illustrated further optical waveguide 3 comprises a coupling device 5 and a coupling device 4. In the variant shown, the coupling device 5 has a coupling surface that is larger than the coupling surface of the coupling device 4. The illustrated further optical waveguide 3 is designed as a periscope optical waveguide. It can be a planar optical waveguide, i.e., designed for optical waveguide in a sagittal direction.

[0075] Figure 6 schematically shows a rotation 10 of the additional optical fiber 3 with respect to the coupling region 9 of the optical fiber 2 and the associated rotation 11 of the projector image. Since the additional optical fiber 3 is customized for the specific position of the projector coupling and AR optical fiber coupling, in particular with regard to its length and an azimuthal angle of rotation 10 relative to the AR optical fiber 2, for a constant orientation of the virtual image, the projector or the image must be rotated azimuthally around the projector coupling point or a coupling point of the coupling device 5 by the same angle, i.e., by the same angle in magnitude and direction. Conventional optics can be used for image rotation, for example, an azimuthally rotatable Schmidt-Pechan prism.

[0076] Figure 7 schematically shows the adjustment of the pupil position 15 as a function of the length of the additional optical fiber 3 in the sagittal direction. The beam path from the projector 12 toward the additional optical fiber is designated by reference numeral 16. The beam path from the output coupling device 19 toward an eye 14 or an eyebox is designated by reference numeral 17. The exit pupil position 15 of the projector 12 lies in the coupling region 9, in particular on the coupling optics, of the AR optical fiber 2 and thus coincides with the AR optical fiber entrance pupil. The additional optical fiber 2 rotates around this pivot point (see arrow 10 in Figure 6). To decouple the requirement for the exit pupil position 15 from the length of the additional optical fiber 3, the projector 12 must be designed accordingly and, for example, its position must be axially shifted (see arrow 13).

[0077] Instead of axially displacing 13 the projector 12, a corresponding zoom lens or an optical relay system can also be provided. The Schmidt-Pechan prism 20 used for this purpose in the example in Figure 8 can, with a modification, also be used simultaneously or supplemented with an optical system 22, e.g., a compensation wedge or a prism, to decouple the angle of incidence of the main ray of the image center from the axial orientation of the projector 12 along a spectacle temple 6. Figure 8 schematically shows, on the left, the ray path 21 through a Schmidt-Pechan prism 20 for rotating the image, and, on the right, its application for compensating a temple angle.

[0078] Figure 9 schematically shows further examples for correcting an oblique coupling angle using suitable optics 22 and 23. As a further option, Figure 10 schematically shows a bracket angle correction using two appropriately aligned mirrors 24 and 25. Beams characterizing two different points of an image are identified by reference numerals 26 and 27. Instead of an image alignment prism 20 or an azimuthal rotation of the projector 12, the azimuthal rotation can also be realized by one or more additional mirrors in the further optical fiber 3, but also in the beam path before or after it.

[0079] The coupling and decoupling elements 4 and 5 for the additional optical waveguide 3 can be refractive (e.g., as a prism), reflective (e.g., one or more mirrors each), or diffractive (e.g., via one or more diffraction gratings). These elements must be optimized with particular regard to coupling efficiency, chromatic aberrations, and scattered light. Depending on the coupling efficiency and beam propagation in the additional optical waveguide 3, individual surfaces of the additional optical waveguide 3 can be provided with absorber elements (e.g., apertures, coatings, etc.).

[0080] The elevation angle of the main beam can be adjusted in the further optical waveguide 3 via the coupling elements so that the effect of the further optical waveguide 3 is adjusted as if one were coupling into the AR optical waveguide 2 without further optical waveguide 3.

[0081] The additional optical waveguide 3 can be designed as a dedicated component or functionally integrated into the lenses, e.g. push and / or pull lenses, in combination with an adhesive with a high refractive index. The additional optical waveguide 3 can also comprise several mirrors in the coupling region near the pupil position 15, whereby the additional optical waveguide 3 can be designed thinner. The coupling optics for the AR optical waveguide 2 are generally coincident with the pupil position 15. In the case of a mirror, this can be designed in one piece. This limits the thickness of the respective waveguide depending on the pupil diameter and the mirror orientation. Alternatively, the pupil layer 15 can also be located in the additional optical waveguide 3. For this purpose, this can, for example, have the shape of a bow tie, as shown in Figure 11.Figure 11 schematically shows another optical waveguide 2 with a central pupil layer 15, shown at the top in a top view and below in a side view. The beam path is indicated by arrows with the reference number 21. With an appropriate design, the thickness and weight of the optical waveguides can be significantly reduced. Furthermore, the pupil layer 15 is accessible independently of a mirror, for example, for stray light optimization (cf. Lyot diaphragm). The AR optical waveguide 2 can generally also be designed with two or more layers, whereby the layers can be rotated and shifted relative to one another before their relative position is secured, for example, with adhesive.

[0082] The exemplary embodiments according to the following figures show a non-sequential optical simulation. Partially partially transparent mirrors were arbitrarily selected as the input and output coupling elements for the optical waveguide. For the sake of simplicity, a copy of the other optical waveguide 3 was chosen as the AR optical waveguide 2. Pupil replication is therefore one-dimensional; accordingly, only a one-dimensional field was selected. However, the concept can also be used for two-dimensional pupil replication, regardless of the coupling principle (refractive, reflective, or diffractive). Optical waveguides 2 and 3 are designed as planar optical waveguides, for example.

[0083] Figures 12, 13 and 14 show schematic perspective views of a beam path through a correspondingly simulated optical arrangement 1 according to the invention at different azimuthal rotation angles of the further optical waveguide 3, e.g. a rotation of a longitudinal axis of the further optical waveguide 3 with respect to a longitudinal axis of the AR optical waveguide 2 around a coupling point. In Figure 12 the rotation angle is 145 degrees, in Figure 13 the rotation angle is 130 degrees and in Figure 14 the rotation angle is 115 degrees. The projector was pushed towards the further optical waveguide 3 (right side) such that the projector exit pupil and the AR optical waveguide pupil are approximately coincident. On the output side (left) the one-dimensional pupil replication can also be seen; these rays would reach the detector if decentered towards the narrow edge of the detector.Bars 31 and 32 indicate the positions of an idealized collimating lens 31 and focusing lens 32, respectively. Bar 33 indicates the plane of the eye and a detector, respectively.

[0084] Figure 15 schematically shows a view of the beam path shown in Figure 14 through a simulated optical arrangement 1 according to the invention in a yz plane. Figure 16 schematically shows a view of the beam path shown in Figure 14 in an xy plane. Figure 17 schematically shows a view of the beam path shown in Figure 14 in an xz plane. Bars 34 and 35 in Figures 15 to 17 each indicate the positions of an idealized collimation lens.

[0085] In the following, with reference to Figures 18 ff., it is described how a size-minimized optical waveguide can be produced. Figure 18 schematically shows a semi-finished product 29 in the form of a wafer with a size-minimized input coupling region, pupil replication region, and output coupling region in an optical waveguide 2. The contour of an optical waveguide matching an exemplary spectacle lens cutout is identified by reference number 30. The wafer is normally cut out to fit a frame and the associated spectacle lens, and the spectacle lens is glued on over its entire surface. To reduce weight, it can be advantageous to cut out the glass wafer along the outer contour identified by reference number 2 and to fill the missing area, i.e. the area within contour 30 up to the surface of contour 2, with low-density material (e.g. adhesive, polymer) whose index is matched to the optical waveguide.

[0086] Since unnecessarily large pupil replication regions and coupling-out regions can create stray light problems, it is advantageous if the wafer is constructed from segments. Figure 19 schematically shows a wafer 29 constructed from segments. Figure 20 schematically shows a section of the wafer 29 shown in Figure 19, for example centered for a specific frame and a specific user group (eye relief). The coupling-out regions 19 and pupil replication regions 53, which are refractively designed in the present case, form individual segments and are minimal in terms of their dimensions in accordance with the described framework conditions. Stray light is thus avoided as far as possible. The individual segments have a simple geometric structure, which is advantageous with regard to cost-effective production. Joining points between the individual segments are not visible with index-adapted joining, e.g. by gluing, etc.

[0087] For diffractive couplers, instead of or in addition to the refractive couplers shown, diffraction gratings can be exposed according to the required apertures. In this case, the wafer 29 itself does not need to be segmented. Only finding the ideal aperture, as described in connection with the following figures, is important.

[0088] Figure 21 schematically shows a semi-finished product 29 in the form of a wafer with an optical fiber 2 for a wide range of users. This design offers an output region 19 suitable for many users, e.g., all users with an interpupillary distance of 49 mm to 76 mm. However, it inevitably requires a very large optical fiber 2. This, in turn, leads to an increased weight of the spectacle lens and a limited selection of possible frames.

[0089] Figures 22 and 23 show variants for size-minimized optical fibers. Figure 22 shows one variant of a size-minimized optical fiber 2, e.g., for an interpupillary distance of 63 mm to 65 mm, and Figure 23 shows three variants of size-minimized optical fibers, each designed for a defined user group. The exemplary design is for the right side of the eye in the direction of vision of the spectacle wearer. The nasal side in the illustration is on the left, temporally right. The optical fiber 36 with the associated output coupling device 41 can be designed for a first interpupillary distance range, e.g., 49 mm to 58 mm. The optical fiber 37 with the associated decoupling device 40 can be designed for a second eye distance range, e.g. 58mm to 67mm, and the optical fiber 38 with the associated decoupling device 39 can be designed for a third eye distance range, e.g. 67mm to 76mm.Furthermore, specific customizations for certain frame models are possible.

[0090] The optical waveguide with input and output coupling and pupil replication elements, which is demonstrated below by way of example, but not exclusively, with partially transparent mirrors (see reference numerals 45 and 46 in Figures 24 to 29), is minimized in size based on a desired field of view of a virtual image and positional tolerances of the optical system relative to the user.Basic parameters are, as already mentioned, in particular the meridional eye distance range, the distance range of the waveguide to the eye along the line of sight to the center of the virtual image, the angular orientation of the waveguide to lines of sight of the image content (for example the line of sight to the center of the image), the size of the eye pupils, the field of view and the respective fields of view for the virtual image and the view through, the distance from the eye pupil to the focal plane of the virtual image, the waveguide material, and the position of the coupling of the image information of an image collimator.

[0091] For an arbitrarily selected spectacle frame and image parameters, the example representations shown in Figures 18 to 23 and the following were generated using the following data: distance 1 m to the virtual image, ±17.7° field of view (half field in sagittal and meridional direction in square form), interpupillary distance (relative to the eye pupil centers when looking at infinite object distance) 64 mm with variations as described above, 15 mm distance from the pupil center to the waveguide (along the line of sight to the center of the virtual image) with variations between 13 mm and 20 mm (depending on the slippage of the spectacle frame along the bridge of the nose of an exemplary human head and usual eye diameter variations, slip direction of the frame approx. -60° to the meridional plane), -10° pantoscopic angle (frame forward tilt angle) and -10° sagittal angle for the direction of view towards the center of the virtual image, -2.4° wrap angle (angle of inclination of the lens to the sagittal plane 90° - 2.4°), a pupil diameter of 1.5 mm to be filled with image information, a commercial spectacle frame (CT scan) assuming the coupling of the image information from the image collimator near the temples, and a waveguide material with refractive indices at 587.56 nm between 1.5 and 2.1 (as in the lenses N-LAF33, N-LASF46B, N-BAF4 or P-SK60 from the manufacturer SCHOTT, whereby N-LASF46B is used for the demonstrated design variant).

[0092] Figures 24 to 29 schematically show a spectacle lens with an optical fiber 2 and the geometric parameters used in a simulation to minimize size. A coupling optic in the form of an image collimator is designated by reference numeral 44. For the viewing angle range of the eye by rotating the eyeball, a range of ±17.5° is assumed around a viewing direction oriented downwards by -2.5° relative to the meridional plane. This is shown in Figure 24, where the corresponding viewing angle range is designated by reference numeral 42. Furthermore, Figure 25 shows an axially symmetric field of view 43 of ±30° for orientation purposes, i.e., a range in which a person can usually still perceive symbols in their peripheral vision.

[0093] Within the gaze cone 42, the eye is oriented so that the line of sight is directed toward the center of a virtual image located one meter away along the line of sight from the pupil center, tilted by -10° around the meridional plane. A field of view 47 with ±17.7° is constructed around this line of sight to the image center. Its intersection 48 with the waveguide back is used to identify the area 49, the so-called "minimal output footprint," from which light is coupled out toward the eye (see Figures 26 and 27). The default is a square virtual image with image corners at ±25° field of view from the line of sight to the image center. Based on this, a volume 50 is spanned, which includes all viewing directions with a filled pupil and indicates the range in which the pupil moves (see Figure 28).For this purpose, two orthogonal elevation angles of the eye model are optimized so that the eye model looks into the corners of the image. The area 51 spanned by the pupil center movement is ideally spherical and depends, among other things, on the distance of the eye from the waveguide. Together with this distance variation along the line of sight, the so-called "eye box" is created: a spatial area in which the eye pupil is located for all relevant variations (with variable angular orientation according to the eye rotation).

[0094] In addition to this variation, there are positional tolerances for the described optical system relative to the eye pupil or the eye box. These include, for example, a possible downward (e.g., 4 mm) or upward (e.g., 1 mm) slippage of the spectacles on the bridge of the nose (e.g., 4 mm) or 1 mm, a lateral tolerance for the attachment of the optical system within the spectacle frame (e.g., ± 1 mm), and measurement tolerances for the interpupillary distance (e.g., ± 1 mm). For the described variations, footprints are recorded using a (semi-)automated analysis process, and an integrated quadrangular footprint 52 is generated from them, which is usually no longer exactly square (see Figure 29). A similar situation applies to the eye box.The footprint 52, integrated across all relevant variations, specifies the necessary minimum area for coupling out, which, as described above, is independent of the selected waveguide technology, for example, independent of the design as diffractive or reflective couplers and pupil replicators.

[0095] For further optimization, a reference geometry is defined based on the integrated footprint 52, which consists of reference coordinate systems, planes, axes and points, as well as reference curves. The reference geometry can be used for the design of the diffractive and reflective coupling and replication elements. With the reference geometry and the footprint from Figure 29, for the application of reflective pupil replication, as well as coupling and decoupling, by specifying the waveguide material (e.g., N-LASF46B glass from SCHOTT), the eye pupil size to be filled (e.g., 1.5 mm diameter), the desired angular division of the pupil replication (e.g., 1°), the minimum lateral extent of the angular division (e.g., 1 mm to 1.5 mm), and the desired coupling position of the image information, e.g.,near the temples, the parameters for a minimally sized optical waveguide 2 are automatically determined in an optimization process, which couples the coupled light toward the eye with a homogeneous radiation intensity (unit [W / sr]). The corresponding geometry is necessary for a homogeneous distribution and coupling of the light, whereby the virtual image appears uniform in color and brightness for visual perception, even with the described variances. The optical design is sufficiently defined by specifically designed partially transparent mirrors 45 and 46.

[0096] The geometric parameters that are automatically optimized are the light propagation volumes within the optical waveguide, the number and position of the semi-transparent mirrors 45 and 46, the thickness of the optical waveguide 2, and the blanks from which the wafer-shaped semi-finished product is constructed. The elevation angles of the coupling and decoupling are designed based on the line of sight to the image center and the pantoscopic angle and the wrap angle, either directly within the geometry model or with the aid of a coupled optical simulation. Depending on the azimuthal position of the reference geometry, for example, depending on the footprint width and / or the coupling position of the image collimator 44, the optical waveguide volume is automatically limited by condition-controlled cuts at the footprint dimensions.This avoids superfluous optical waveguide regions that are disadvantageous in terms of optical properties, such as stray light, and may be disadvantageous in terms of weight. See Figures 19 and 20, which show two examples of wafers 29 with size-minimized optical waveguides 2 produced according to the described method. The optical waveguide 2 shown in Figure 19 is size-minimized for a large user group, and the optical waveguide 2 shown in Figure 20 is size-minimized for a user group with an eye distance within a specified range.

[0097] The required reflectances and transmittances of the partially transmissive mirrors 45 and 46 are also determined automatically. They depend, among other things, on the number of mirrors, which is automatically varied during the geometry optimization. The aforementioned fundamental radiometric properties of the respective mirrors 45 and 46 are important for a coupled non-sequential optics simulation, with which all of the parameters described above can be finely optimized. In particular, this concerns multi-objective optimization with regard to volume minimization and optical performance, for example, tolerance and stray light desensitization of the geometry, but can also include coupling to structural mechanics simulations, for example, for desensitizing the optics system with respect to temperature variations and other mechanical load cases.

[0098] If necessary, the radiometric properties of the mirrors and the coupled simulations / multi-objective optimizations can be described in detail, but this will be omitted here for time reasons. The partially transparent mirrors can be realized, for example, using dielectric multi-layer coatings or holographic optical elements (HOEs).

[0099] For attaching the image collimator 44 to the optical waveguide 2 and aligning it along the temple of the spectacle frame, a corresponding optical group is provided, which can itself be designed as an optical waveguide. The optical group 44 can decouple the alignment of the image collimator along the temple and the required incoming direction of the main ray of the image center from one another, e.g. through a suitable optical design. This optical group 44 can be important as a boundary condition for system optimization. The described optical design process produces an optical waveguide 2 with minimized dimensions that is integrated into a wafer-shaped semi-finished product 29. This semi-finished product 29 is individually cut out for a corresponding frame shape and / or the corresponding user group. The optical design was carried out in CREO Parametric.

[0100] A parametrically coupled optics simulation and fine optimizations can be carried out, for example, with ZEMAX.

[0101] List of reference symbols

[0102] 1 optical arrangement

[0103] 2 optical fibers

[0104] 3 additional optical fibers

[0105] 4 Decoupling device

[0106] 5 Coupling device

[0107] 6 Fastening device

[0108] 7 Decoupling area

[0109] 8th version

[0110] 9 Coupling area / coupling device

[0111] 10 turns

[0112] 11 rotation

[0113] 12 projectors

[0114] 13 axial displacement

[0115] 14 Eye

[0116] 15 Pupil position

[0117] 16 Beam path

[0118] 17 Beam path

[0119] 19 Decoupling device, decoupling area

[0120] 20 Schmidt-Pechan prism

[0121] 21 Beam path

[0122] 22 Optics

[0123] 23 Optics

[0124] 24 mirrors

[0125] 25 mirrors

[0126] 26 light beam

[0127] 27 Light beam

[0128] 28 lenses

[0129] 29 wafers

[0130] 30 Contour for lens cutout

[0131] 31 Position of an idealized collimating lens

[0132] 32 Position of an idealized focusing lens

[0133] 33 Detector plane 34 Position of an idealized collimation lens

[0134] 35 Position of an idealized collimating lens

[0135] 36 optical fibers

[0136] 37 optical fibers

[0137] 38 optical fibers

[0138] 39 Decoupling device

[0139] 40 decoupling device

[0140] 41 Decoupling device

[0141] 42 viewing angle range

[0142] 43 field of vision

[0143] 44 coupling optics / image collimator

[0144] 45 partially transparent mirrors

[0145] 46 partially transparent mirrors

[0146] 47 constructed visual field

[0147] 48 Section of the constructed field of view with the

[0148] Waveguide back (“footprint”)

[0149] 49 Decoupling area

[0150] 50 spanned volume

[0151] 51 Area spanned by the pupil center movement

[0152] 52 integrated square footprint

[0153] 53 Pupil replication area

Claims

Patent claims 1. An optical arrangement (1) comprising an optical waveguide (2) for radiating images that can be perceived as virtual images, and a fastening device (6) for fastening the optical arrangement (1) to a person's head, the fastening device (6) comprising an output coupling region (7) for arranging a projector (12), the optical waveguide (2) having an input coupling region (9), characterized in that the optical arrangement (1) has a further optical waveguide (3) with an input coupling device (5) and an output coupling device (4), the further optical waveguide (3) being arranged in the beam path between the output coupling region (7) of the fastening device (6) and the input coupling region (9) of the optical waveguide (2).

2. Optical arrangement (1) according to claim 1, characterized in that the decoupling region (7) of the fastening device (6) is connectable or connected to the coupling device (5) of the further optical waveguide (3) and / or the decoupling device (4) of the further optical waveguide (3) is connectable or connected to the coupling region (9) of the optical waveguide (2).

3. Optical arrangement (1) according to claim 1 or 2, characterized in that the further optical waveguide (3) is designed as a persiscope optical waveguide, and / or the coupling device (5) and / or the coupling device (4) of the further optical waveguide (3) is designed to be refractive and / or diffractive and / or reflective and / or transmissive and / or comprises at least one holographic optical arrangement.

4. Optical arrangement (1) according to one of claims 1 to 3, characterized in that the optical waveguide (2) and / or the further optical waveguide (3) is individually designed according to at least one specified individualization parameter and / or is constructed from segments.

5. Optical arrangement (1) according to claim 4, characterized in that the at least one individualization parameter is an interpupillary distance and / or a head width and / or at least one geometric parameter of a spectacle frame and / or a position of the coupling-in region (9) of the optical waveguide (2) and / or a position of the coupling-out region (19).

6. Optical arrangement (1) according to claim 4 or 5, characterized in that the at least one individualization parameter is the length of the further optical waveguide (3) and / or the position of the further optical waveguide (3) in relation to the optical waveguide (2) and / or an angle of rotation (10) of the further optical waveguide (3) relative to the optical waveguide (2).

7. Optical arrangement (1) according to one of claims 1 to 6, characterized in that the optical arrangement (1) comprises a spectacle frame with a frame contour (8) and the further optical waveguide (3) is arranged displaceably within the frame contour (8).

8. Optical arrangement (1) according to one of claims 1 to 7, characterized in that the further optical waveguide (3) is designed as a planar optical waveguide and / or is designed for optical waveguiding in a sagittal direction.

9. Optical arrangement (1) according to one of claims 1 to 8, characterized in that a rotation angle (10) of a longitudinal axis of the further optical waveguide (3) relative to a fixed coupling point in the optical waveguide (2) and a rotation angle (11) of an image to be coupled in relative to a fixed coupling point in the further optical waveguide (3) have the same amount and the same direction.

10. Optical arrangement (1) according to one of claims 1 to 9, characterized in that an optical device (20) is arranged in the beam path between a projector (12) and the coupling device (5) of the further optical waveguide (3), which device causes a complete image reversal without beam offset.

11. Optical arrangement (1) according to one of claims 1 to 10, characterized in that the optical arrangement (1) comprises a projector (12) which is arranged and / or adjusted such that the exit pupil (15) of the projector (12) lies on the coupling region (9) of the optical waveguide (2) or in the further optical waveguide (3).

12. Optical arrangement (1) according to one of claims 1 to 11, characterized in that the optical arrangement (1) comprises a projector (12) which is arranged axially displaceably (13) along the fastening device (3), and / or the optical arrangement (1) comprises an optical device (20, 22, 23) which is arranged in the beam path between the projector (12) and the further optical waveguide (3) and which is designed to adapt the exit pupil position (15) of the projector (12).

13. Optical arrangement (1) according to one of claims 1 to 12, characterized in that the optical arrangement (1) comprises an optical device (20, 22, 23) for correcting an angle of the fastening device (6) with respect to the coupling device (5) of the further optical waveguide (3), wherein the optical device (20, 22, 23) is arranged between the coupling-out region (7) of the projector (12) and the coupling-in device (5) of the further optical waveguide (3).

14. Optical arrangement (1) according to one of claims 1 to 13, characterized in that the optical arrangement (1) comprises at least one lens which comprises a cutout or recess adapted to the geometry of the further optical waveguide (3) and / or wherein the refractive index and / or the refractive index dispersion of the further optical waveguide (3) is adapted to the refractive index and / or the refractive index dispersion of the at least one lens and / or to a boundary layer arranged between the further optical waveguide (3) and the lens.

15. Optical arrangement (1) according to one of claims 1 to 14, characterized in that the optical waveguide (2) is designed as a size-minimized optical waveguide and the further optical waveguide (3) is designed as a length- and / or rotation angle-corrected further optical waveguide.

16. Head-mounted display comprising an optical arrangement (1) according to one of claims 1 to 15.

Images