[go: up one dir, main page]

EP4540553A1 - Guide d'ondes optiques possédant un élément grin incurvé - Google Patents

Guide d'ondes optiques possédant un élément grin incurvé

Info

Publication number
EP4540553A1
EP4540553A1 EP23732871.1A EP23732871A EP4540553A1 EP 4540553 A1 EP4540553 A1 EP 4540553A1 EP 23732871 A EP23732871 A EP 23732871A EP 4540553 A1 EP4540553 A1 EP 4540553A1
Authority
EP
European Patent Office
Prior art keywords
optical waveguide
refractive index
optical
grin
grin element
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP23732871.1A
Other languages
German (de)
English (en)
Inventor
Christoph Menke
Norbert Kerwien
Andrea Berner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Carl Zeiss AG
Original Assignee
Carl Zeiss AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Carl Zeiss AG filed Critical Carl Zeiss AG
Publication of EP4540553A1 publication Critical patent/EP4540553A1/fr
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
    • G02B6/0045—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it by shaping at least a portion of the light guide
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays
    • G02B27/017—Head mounted
    • G02B27/0172—Head mounted characterised by optical features
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/0025—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for optical correction, e.g. distorsion, aberration
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B3/00—Simple or compound lenses
    • G02B3/0087—Simple or compound lenses with index gradient
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/02—Optical fibres with cladding with or without a coating
    • G02B6/028—Optical fibres with cladding with or without a coating with core or cladding having graded refractive index
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays
    • G02B27/0101—Head-up displays characterised by optical features
    • G02B2027/011—Head-up displays characterised by optical features comprising device for correcting geometrical aberrations, distortion
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays
    • G02B27/0101—Head-up displays characterised by optical features
    • G02B2027/013—Head-up displays characterised by optical features comprising a combiner of particular shape, e.g. curvature

Definitions

  • the present invention relates to an optical waveguide for arrangement in the beam path of an optical arrangement, for example a head-mounted display (HMD), a head-up display (HUD), a near-to-eye display or an imaging arrangement or imaging -Device (smart glasses with, for example, gesture recognition or eye tracking).
  • an optical arrangement for example for one of the aforementioned applications, an image capture device and an image display device.
  • Head-mounted displays 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 VR or MR glasses or VR or MR helmets are used in numerous contexts.
  • AR Augmented Reality
  • VR headsets VR - Virtual Reality
  • MR headsets MR - Mixed Reality
  • VR or MR glasses or VR or MR helmets are used in numerous contexts.
  • the light waves are usually guided after coupling into an optical waveguide by means of total reflection until they are coupled out.
  • augmented reality glasses” or “AR glasses” for short, they see a coupled or reflected “virtual image” superimposed on their image of the real world (“real image”).
  • a beam combiner which on the one hand is transparent to the ambient light and on the other hand also directs a beam of rays generated by an external imager onto the eye or into an eyebox.
  • the eye perceives this bundle of rays as a virtual image.
  • the beam path of the image of the real environment and the coupled-in are used to describe the beam path
  • Each virtual image defines an imaging path.
  • an imaging path is the path of the light from the object, e.g. an object in the real environment, or from the imager/projector, which emits the virtual image to be coupled in, to the place where the image is created or the image is perceived, e.g. the eye of a user or the eyebox, understood.
  • An optical waveguide is understood to mean a waveguide which is designed to guide or forward light waves through total reflection on surfaces of the waveguide inside the waveguide.
  • Light waves are understood to mean electromagnetic waves with wavelengths in the range between 300 nm (ultraviolet light) and 2 ⁇ m (infrared light), in particular light waves in the visible range and near infrared and near ultraviolet range.
  • a head-mounted display e.g. 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 means of total reflection and finally coupled out, so that a user of the head-mounted display Mounted displays can see a virtual image.
  • the area of space from which the virtual image passes through you What is visually perceptible to the user is also known as an eyebox.
  • the two outer surfaces of the optical waveguide are often designed as parallel flat surfaces so that neither optical refractive power is introduced within the optical waveguide nor aberrations that impair the image quality are generated.
  • head-mounted displays e.g. AR headsets
  • This one lens or these several additional lenses are used to correct the ametropia (ambiguous vision) or presbyopia (presbyopia) of the eye (pull lens) and/or to make the virtual image appear focused at a desired distance (pull lens) , without affecting the image of the real environment (push lens).
  • Eyeglass lenses are usually meniscus-shaped. If an optical fiber is integrated as a plane-parallel plate into a lens that is to be used as a head-mounted display, the combination of the optical fiber with the push-pull lenses inevitably leads to thick, voluminous and heavy systems. Obviously, the total thickness of a lens consisting of a push lens, a flat optical fiber and a pull lens increases with the curvature of the meniscus. However, stronger curvatures are necessary to correct larger ametropia (ametropia, e.g. more than +/-3 diopters) or presbyopia in progressive lenses.
  • ametropia ametropia, e.g. more than +/-3 diopters
  • a curved optical fiber usually leads, and especially with large fields of view or FOVs (FOV field of view), to strong astigmatic imaging errors in the virtual image that cannot be compensated for within the optical fiber.
  • FOVs field of view
  • a correction outside the optical fiber is also not possible, as the view through the glasses (image path of the real image of the environment) of the objects in the outside world must not be impaired.
  • the optical waveguide according to the invention for arrangement in the beam path of an optical arrangement comprises a device for coupling out and/or coupling in an imaging beam path, i.e. light waves.
  • the waveguide according to the invention can be, for example, a waveguide of a head-mounted display.
  • the waveguide can be designed in particular to generate a virtual image and at the same time to view the environment, i.e. to generate a real image of the environment. It can also be designed to be arranged between an imaging unit and an eyebox of a head-mounted display.
  • the optical waveguide according to the invention comprises a GRIN element.
  • a GRIN element or a GRIN material is understood to mean a gradient index element or gradient index material (GRIN) which has a refractive index curve or a refractive index distribution with a gradient.
  • the GRIN element is designed for light wave guidance by means of total reflection and is not part of a device for coupling in and/or decoupling an imaging beam path, i.e. light waves. In other words, it can be arranged as an integral part of the optical waveguide in the beam path between a device for coupling in and a device for coupling out.
  • the GRIN element of the optical waveguide according to the invention has at least one curved surface.
  • the surface can be concave or be convexly curved.
  • the surfaces can also be designed as free-form surfaces or aspherical surfaces.
  • An aspherical surface is understood to be a rotationally symmetrical optical surface whose radius of curvature changes radially with the distance from the center.
  • the GRIN element also has a refractive index distribution, which is designed to reduce the aberrations caused by the curvature of the GRIN element in an imaging path of a virtual image, which is generated by means of light waves guided in the optical waveguide by total reflection.
  • the refractive index distribution is therefore designed to at least partially correct, preferably completely correct, the aberrations mentioned.
  • the aberrations of the virtual image to be corrected arise from the curvature of the waveguide, since reflection (total reflection on the surfaces of the optical waveguide) has an optical effect on a curved surface.
  • the curved surface changes the convergence of the beam. With multiple reflections, the convergence changes with each reflection, causing aberrations, especially strong astigmatism, to occur.
  • the refractive index curve of the GRIN material now makes it possible to correct these typical aberrations of a simple curved optical fiber.
  • the GRIN material offers additional degrees of freedom in order to optionally reduce the aberrations of the real image of the environment caused by the GRIN element, also through the refractive index curve and, if necessary, through an adapted design of the curvature of the at least one surface, preferably the two surfaces, e.g. to correct completely or at least partially.
  • the at least one surface for example a first and/or a second surface can in particular be spherical, cylindrical, toric or aspherically curved or designed as a free-form surface.
  • the GRIN element preferably consists of isotropic material that does not have birefringence.
  • the GRIN element has a refractive index distribution, which is additionally designed to detect the aberrations induced or caused by the GRIN element in an imaging path of a real image of the environment, i.e. the real or actual environment, which is caused by the GRIN element runs through, to reduce, in particular to correct at least partially or completely.
  • the GRIN element is designed to reduce or correct the imaging errors of the coupled-in virtual image that are typically generated in a simple curved optical waveguide without a GRIN refractive index curve, as well as optionally additionally the aberrations of the real image of the actual environment (as seen through the waveguide towards the surroundings).
  • the aberrations induced in the imaging path of the real image of the environment by the GRIN element can be aberrations which are induced by the curvature of the GRIN element and/or which are caused by the aberrations induced in the imaging path of the virtual image Aberrations designed refractive index distribution are induced.
  • the optical waveguide according to the invention has the advantage that, due to its curved design, it can be adapted to a meniscus shape of a spectacle lens, in particular at least one of the lenses described above.
  • the GRIN element can be used, for example, to reduce or correct strong astigmatic errors in the virtual image without impairing the view of the objects in the outside world through the optical fiber.
  • the invention enables a compact and lightweight arrangement with a reduced system thickness (see Fig. 1). This is particularly advantageous from an aesthetic point of view. It can be compared Significantly more attractive eyewear designs can be achieved using plane-parallel optical fibers.
  • a large, aberration-free field of view (FOV) can be realized for the imaging path of the virtual image.
  • Transformation optics are characterized by the ability to “bend” or direct light or electromagnetic waves in any way for a desired application. This is done by tailoring the medium in which the electromagnetic wave propagates. The necessary properties of the medium are derived through a mathematical transformation. The special thing about this is that the Maxwell equations remain in their form, even though the coordinates are transformed. Instead, the spatial distribution of the material parameters ⁇ (permittivity, dielectric constant) and ⁇ (magnetic permeability) "transform" or change.
  • a coordinate transformation is carried out: q 1 (x, y, z) q 2 (x, y, z) q 3 (x, y, z)
  • the Maxwell equations are set up in the new coordinate system, whereby the form of the Maxwell equations does not change.
  • Maxwell equations can therefore be transformed into a new geometry or coordinate system that is particularly advantageous for describing a specific application.
  • ⁇ and ⁇ must be changed.
  • a planar optical waveguide is subjected to a suitable transformation, it can be converted into any shape, in particular into a spherically curved optical waveguide. It is also possible to convert it into a cylindrical, toric, aspherical or free-form waveguide, for example.
  • the refractive index curves or the refractive index distribution (represented via ⁇ and ⁇ ) must be adjusted according to the transformation.
  • the light wave field that propagates through a waveguide transformed in this way remains aberration-free - as in a planar optical waveguide. The derivation is described in detail in the context of the first and second embodiment variants.
  • the refractive index distribution of the GRIN element can have a radially symmetrical and/or cylindrical or cylindrically symmetrical and/or toric refractive index distribution and/or have a refractive index distribution which has at least one surface with a constant refractive index, wherein the at least one surface is cylindrical or toric or spherical or aspherical or designed as a free-form surface.
  • the at least one surface with a constant refractive index can coincide with the at least one curved surface of the GRIN element or run parallel to it. This variant has manufacturing advantages.
  • the origin of the coordinate system lies at the eye pivot point or a center point of an eyebox or on a straight line that connects an eye pivot point and a center point of an eyebox.
  • n(r) n 1 *r'/r
  • r' is the radius of curvature of the first surface
  • r is the radius, i.e Distance from the origin of the coordinate system which defines the radius of curvature of the first surface r'
  • m is the refractive index of the material of the GRIN element on the first surface.
  • the maximum thickness of the GRIN element in the direction of the optical axis or the main beam direction of an imaging path of the real image of the environment or in the radial direction can be at least 0.1 mm and/or a maximum of 10 mm, in particular between 0.1 mm and 10 mm, preferably between 0 .5mm and 3mm, for example between 1mm and 2mm.
  • the dimensions mentioned are particularly advantageous in connection with head-mounted displays when used in combination with spectacle lenses for correcting ametropia, since they enable compact optical arrangements.
  • the change in the refractive index ⁇ n in the GRIN element is between 0.005 and 0.20.
  • the change in the refractive index ⁇ n in the GRIN element, in particular in the radial direction (radial refractive index swing) can be between 0.01 and 0.15.
  • the gradient ⁇ n/dx of the refractive index n in a direction x can be, for example, between 0mm -1 and 0.02mm -1 .
  • it is Gradient ⁇ n/dx of the refractive index n in a direction x perpendicular to the main beam direction of an imaging path of the real image of the environment or in a direction x parallel to the main beam direction of an imaging path of the real image of the environment or in a radial direction x or in a direction x perpendicular to the optical Axis or in a direction x parallel to the optical axis between 0mm -1 and 0.02mm -1 .
  • the first surface and/or second surface can be toric or spherical or aspherical or cylindrical or cylindrically symmetrical or designed as a free-form surface.
  • the projection image of the virtual image through the optical fiber but also the quality of the viewing application (real image of the environment) can be optimized at the same time. If at least one push and/or pull lens is used, these are included in the optimization of the view image (real image of the environment) and/or the virtual image.
  • the push and pull lenses can be designed as separate elements attached via an air gap or via an airgel or a liquid or as elements connected to the optical waveguide, in particular to the GRIN element (embedded GRIN waveguide) and even have an inhomogeneous refractive index -Distribution (refractive index profile) and/or have free-form surfaces.
  • the connection between the push and/or pull lens and the optical fiber can be made by molding, gluing or cementing.
  • the lenses can also be printed on the optical fiber using 3D printing.
  • the lenses and the optical fiber can also be manufactured in one piece, for example using 3D printing.
  • the GRIN element is designed to be zero in the imaging path of the real and/or virtual image to introduce different refractive power, for example positive and/or negative refractive power.
  • it is designed to manipulate a beam path or a wavefront like a refractive lens or analogous to a refractive lens.
  • the GRIN element can therefore act like a pull lens and/or a push lens. It can therefore be designed to correct ametropia, in particular sphere and/or astigmatism, and/or to focus a virtual image.
  • This has the advantage that at least one of the lenses mentioned for correcting ametropia and/or for focusing a virtual image is dispensed with and the system thickness can therefore be reduced.
  • the effect of the push lens and/or the pull lens is taken over by the GRIN element.
  • a curved waveguide in particular adapted to the meniscus shape of a spectacle lens, can be designed according to the present invention so that it acts like an optically flat waveguide by using an appropriately designed gradient index material (GRIN) instead of the homogeneous material.
  • GRIN gradient index material
  • the GRIN material can partially or completely compensate for the aberrations (e.g. astigmatism) caused by the curved surfaces in the waveguide, so that the quality of the virtual image for a user of a head-mounted display, e.g AR headsets, is acceptable.
  • the aberrations caused by the GRIN element of the optical waveguide in the imaging path of a real image of the environment i.e.
  • the GRIN element in the curved optical waveguide is designed such that the aberrations arising in the imaging path of a real image of the environment are small (astigmatism ⁇ 0.15 dpt) and no compensation is required.
  • the refractive index within the GRIN element can vary in three dimensions of a fixed coordinate system or reference system, i.e. have a gradient in all three dimensions.
  • the refractive index within the GRIN element varies in at least a first and a second dimension of a fixed coordinate system or reference system, i.e. has a gradient in these dimensions.
  • the refractive index along a third dimension of the defined coordinate system can be constant, i.e. have no gradient, the third dimension including a tilt angle with the main beam direction or the direction of the optical axis of an imaging path of the real image of the environment.
  • the amount of the tilt angle is greater than 2 degrees.
  • the amount of the tilt angle can be between 5 degrees and 20 degrees, for example. This configuration enables simplified production of the optical waveguide, with the costs for this being reduced.
  • the optical arrangement according to the invention comprises at least one optical element with at least one curved surface.
  • the at least one optical element can be designed as a lens, for example a meniscus-shaped or plano-concave or plano-convex lens.
  • the lens can e.g. be designed as a spectacle lens for correcting ametropia, in particular ametropia and/or presbyopia, and/or for focusing a virtual image.
  • the at least one optical element can also be designed as another optical element, for example a Fresnel lens, a diffractive or holographic optical element or as a GRIN lens, etc.
  • the optical arrangement according to the invention comprises at least one previously described optical waveguide according to the invention.
  • the at least one optical element and the optical waveguide are in the beam path of the imaging path of the real and/or virtual image arranged one behind the other.
  • the at least one optical element can be arranged in the beam path of the imaging path of the real and/or virtual image in front of or behind the optical waveguide, in particular in front of or behind the GRIN element.
  • the at least one optical element and the optical waveguide can be arranged one behind the other in a defined main beam direction or direction of the optical axis of an imaging path of the real image of the environment through the at least one optical element and through the optical waveguide.
  • the optical waveguide, in particular the GRIN element can therefore be arranged in the beam path of the imaging path of the real and/or virtual image in front of or behind the at least one optical element.
  • the GRIN element of the optical waveguide can be arranged geometrically between an eyebox or the eye of a viewer and a virtual image plane.
  • the at least one optical element can be arranged geometrically between the GRIN element of the optical waveguide and an eyebox or the eye of a viewer.
  • the optical arrangement can be for a head-mounted display (HMD), which is, for example, an AR headset or a VR headset, or an MR headset or an AR or VR or MR glasses or an AR - or VR or MR helmet or data glasses, or for a head-up display (HUD), for a near-to-eye display or for an imaging arrangement or an imaging device (smart glasses with for example gesture recognition or eye tracking).
  • HMD head-mounted display
  • HUD head-up display
  • the optical arrangement according to the invention has the features and advantages already mentioned in connection with the optical waveguide according to the invention.
  • the optical element can be designed as a refractive lens (e.g. spectacle lens) and/or for correcting ametropia, e.g. nearsightedness and/or farsightedness and/or astigmatism and/or presbyopia (presbyopia) etc., and/or for focusing a virtual image be.
  • the optical element for correcting ametropia can be in the imaging path of the real image Environment and / or for correcting ametropia in the imaging path of the virtual image and / or for focusing the virtual image in the imaging path of the virtual image.
  • the optical element can in particular be designed as spherical, aspherical or as a free-form lens.
  • the optical arrangement according to the invention can, for example, comprise at least one push lens and/or at least one pull lens.
  • the pull lens allows the virtual image to appear at a desired distance in front of the viewer's eye and, if necessary, corrects the wearer's ametropia for the virtual image. Depending on the ametropia, it can be collecting or dispersing.
  • a push lens ensures that the image of the real environment is corrected for a viewer, e.g. someone wearing glasses. Since the viewer or wearer always perceives the environment through the system consisting of optical fibers, push and pull lenses, the combination of these elements must be adapted to the respective viewer or wearer.
  • the optical waveguide is preferably designed such that the curvature of at least one of the surfaces of the GRIN element (e.g. the curvature of the first surface and/or the curvature of the second surface) is adapted to the curvature of the at least one curved surface of the at least one optical element.
  • the curvature of the GRIN element can be adapted to the meniscus shape of a spectacle lens.
  • the curvature of the GRIN element makes it possible to place the GRIN element directly onto the optical element.
  • the GRIN element and the optical element can have the same curvature over at least 50 percent, for example over at least 80 percent, preferably 100 percent, of the surfaces facing each other when applied.
  • the at least one optical element can be designed as a separate element or as an element connected to the optical waveguide in a fixed or detachable manner or by fixed spacers.
  • the optical element can in turn have an inhomogeneous refractive index distribution and/or a free-form surface.
  • the Optical arrangement according to the invention comprises at least one further GRIN element for reducing, for example for compensating, aberrations induced by the GRIN element along an imaging path of the real image of the environment.
  • the further GRIN element can be a separate component or element. However, it can also be part of the at least one optical element with at least one curved surface.
  • the image display device according to the invention comprises at least one optical waveguide according to the invention or a previously described optical arrangement according to the invention.
  • the image capture device according to the invention comprises at least one optical waveguide according to the invention.
  • the image capture device can be an imaging arrangement or imaging device (smart glasses with, for example, gesture recognition or eye tracking).
  • the image display device according to the invention and the image capture device according to the invention have the features and advantages already mentioned.
  • the term “and/or,” when used in a series of two or more items, means that any of the listed items may be used alone, or any combination of two or more of the listed items may be used. For example, if a composition is described that contains components A, B and/or C, the composition 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.
  • Fig. 1 shows schematically variants of a lens arrangement of an AR headset.
  • Fig. 2 shows schematically the beam path through a plane-parallel waveguide.
  • Fig. 3 shows schematically the beam path through a curved waveguide.
  • FIG. 4 shows schematically the transverse deviations that occur in a waveguide shown in FIG. 3 for different viewing angles.
  • Fig. 5 shows schematically an optical waveguide according to the invention according to a first and a second embodiment variant in a sectioned view.
  • FIG. 6 shows the beam path through an optical waveguide according to the invention and the refractive index distribution in the GRIN element of the optical waveguide according to a third embodiment variant.
  • Fig. 7 shows the transverse deviations for different image angles for the third embodiment variant.
  • 8 shows the beam path through an optical waveguide according to the invention and the refractive index distribution in the GRIN element of the optical waveguide according to a fourth embodiment variant.
  • Fig. 9 shows the transverse deviations for different image angles for the fourth embodiment variant.
  • FIG. 10 shows the beam path through an optical waveguide according to the invention and the refractive index distribution in the GRIN element of the optical waveguide according to a fifth embodiment variant.
  • Fig. 11 shows the transverse deviations for different image angles for the fifth embodiment variant.
  • FIG. 12 shows the beam path through an optical waveguide according to the invention and the refractive index distribution in the GRIN element of the optical waveguide according to a sixth embodiment variant.
  • Fig. 13 shows the transverse deviations for different image angles for the sixth embodiment variant.
  • FIG 14 shows the beam path through an optical waveguide according to the invention and the refractive index distribution in the GRIN element of the optical waveguide according to a seventh embodiment variant.
  • Fig. 15 shows the transverse deviations for different image angles for the seventh embodiment variant.
  • Fig. 16 shows the spherical refractive power of the optical waveguide of the seventh embodiment variant in an imaging path of a real image of the environment.
  • Fig. 17 shows the astigmatism of the optical waveguide of the seventh embodiment variant in an imaging path of a real image of the environment.
  • FIG 18 shows the beam path through an optical waveguide according to the invention and the refractive index distribution in the GRIN element of the optical waveguide according to an eighth embodiment variant.
  • Fig. 19 shows the transverse deviations for different image angles for the eighth embodiment variant.
  • Fig. 20 shows the spherical refractive power of the optical waveguide of the eighth embodiment variant in an imaging path of a real image of the environment.
  • Fig. 21 shows the astigmatism of the optical waveguide of the eighth embodiment variant in an imaging path of a real image of the environment.
  • Fig. 22 shows schematically one according to the invention
  • Fig. 23 shows schematically one according to the invention
  • Figure 1 shows schematically variants of a lens arrangement 1 of an AR headset.
  • a and (b) are example versions of a positive spectacle meniscus lens 3 for correcting farsightedness and a negative spectacle meniscus lens 4 for correcting myopia, as well as under (c) and (d) two example versions of a push-pull lens combination 3, 4 including planar optical fiber 2 for a far-sighted headset wearer.
  • Variant (c) completely corrects the ametropia (sphere and cylinder) in the viewing direction through the two meniscus-shaped lenses 3, 4, but has a very large system volume.
  • Variant (d) designs the push and pull lenses 3, 4 as plano-convex or plano-concave lenses, which makes a much more compact system volume possible, but the ametropia cannot be corrected sufficiently well.
  • the inner surfaces of the push and pull lenses 3, 4 have the same radius of the adjacent optical waveguide surface.
  • This form of design enables both the most compact system volume and fully corrected ametropia.
  • the system thickness is marked by arrows with reference number 9 and the system volume by arrows with reference number 19.
  • the aperture or eyebox i.e. the position from which a virtual image generated by means of the waveguide 2, 20 can be visually perceived, is marked with the reference number 6.
  • an optical axis 7 of the imaging path of the real image of the environment is defined, which at the same time defines the viewing direction through the lens arrangement 1.
  • the central axis of the lens arrangement 1 is marked with the reference number 8 and coincides with the optical axis 7 in the examples shown.
  • Figure 2 shows schematically the beam path 5 through a plane-parallel optical waveguide 2, which has flat surfaces 14.
  • the optical waveguide 2 has a coupling device 10 in the form of a coupling surface. He also has a decoupling device 11, which decouples light waves from the optical waveguide 2 in the direction of an eyebox.
  • FIG. 3 shows schematically the beam path 5 through a curved optical waveguide 2. Collimated light is coupled into the optical waveguides 2 shown in FIGS. 2 and 3, which is coupled out collimated in FIG. 2 after the reflections on the flat surfaces 14. In the case of the curved optical waveguide 2 of FIG. 3, however, the coupled-out light is no longer collimated and has strong astigmatism. 4 shows schematically the transverse deviations that occur in an optical waveguide 2 shown in FIG. 3 for different viewing angles.
  • the reference circle shown has a diameter of 60 arc minutes.
  • Figure 5 shows schematically a section or partial area of an optical waveguide 20 according to the invention according to a first and a second embodiment variant in a sectioned view.
  • the optical waveguide 20 has a first surface 12 with a
  • the first surface 12 and the second surface 13 are designed to be concentric.
  • the optical waveguide 20 is cylindrically shaped and the first surface 12 and the second surface 13 form concentric cylindrical surface partial surfaces.
  • a corresponding derivation can also be carried out for the permeability tensor ⁇ .
  • the optical waveguide 20 is spherically shaped and the first surface 12 and the second surface 13 form concentric spherical partial surfaces.
  • R dr/dr'.
  • the planar waveguide transformed to a sphere behaves like an optically uniaxial crystal with the normal refractive index: and the extraordinary refractive index:
  • the GRIN element can be manufactured in all variants by arranging foils with appropriate refractive indices one on top of the other.
  • the GRIN element has a toric or spherical geometry.
  • FIG. 6 A third variant is described with reference to Figures 6 and 7.
  • two Cartesian coordinate systems (x,y,z) and (x',y',z') are defined at the top, which rotate around the x-axis or the x'-axis corresponding to the x-axis at an angle a are arranged tilted towards each other.
  • the z-direction defines the main beam direction or direction of the optical axis of the imaging path of the real image of the environment (viewing direction).
  • the information in the following figures (in particular Figures 6, 8 and 10) and embodiment variants also refer to these coordinate systems.
  • Figure 6 also shows the beam path through an optical waveguide 20 according to the invention in a sectional view in a yz plane and the refractive index distribution in the GRIN element of the optical waveguide in an x'-y' plane.
  • the optical waveguide 20 shown has a thickness 22 of 2mm in the z-direction and a length 23 of 22mm in the y-direction.
  • the centers of curvature are on the z-axis and are offset from each other by 2mm.
  • the outer surfaces of the GRIN element are therefore not concentric.
  • the field angle range considered is 10° x 10°.
  • the optical waveguide 20 has a GRIN element in the area shown, which consists of a GRIN material.
  • the refractive index distribution within the GRIN element is shown in Figure 6 below along the x'-y' plane.
  • the refractive index preferably varies continuously, but can also be reproduced by individual layers or areas with a constant refractive index, as shown in Figure 6 below and in corresponding figures of the further embodiments.
  • the refractive indices of the individual areas are given as examples in brackets in the figures.
  • the GRIN element causes light waves coupled out of the waveguide 20 to form a collimated beam path.
  • the astigmatism in the virtual image initially caused by the curvature of the optical waveguide 20 is therefore compensated for by the gradient index distribution within the GRIN element.
  • the waveguide in Figure 6 images an object (at infinity) in the object plane onto an image plane (at infinity). Rays that emanate from a single object point form a parallel bundle of rays, ie all rays are parallel when they are coupled onto the coupling surface.
  • the individual beams of rays in Figure 6 arise from different object points in the object plane.
  • the angle between an incident beam of rays and the optical axis is called the field angle.
  • the beams of rays are coupled out at different angles (image angles) on the decoupling surface.
  • image angles image angles
  • all rays in a single coupled-out beam are again exactly parallel to one another. Since the refractive index distribution in the present embodiment variant does not exactly satisfy the equations of a transformation optics, aberrations, in particular astigmatism, occur.
  • the individual rays in a beam are then no longer parallel, but show individual directional deviations (transverse deviations). The sizes of these transverse deviations are therefore a measure of the size of the aberrations in the imaging path of the virtual image.
  • Figure 7 shows the transverse deviations for different field angles in a pupil plane (x F - y F plane) for the present embodiment variant.
  • the diameter of the reference circle shown is 2 arc minutes.
  • XAN denotes the field angle when rotating about the y F -axis of the pupil plane and
  • YAN denotes the field angle when rotating about the x F -axis of the pupil plane, each in degrees.
  • the transverse deviation shown in the middle of the bottom line refers to a field angle XAN of 0° and YAN of 0°
  • the transverse deviation shown to the left occurs with a field angle YAN of -5° and a field angle XAN of 0°.
  • a transverse deviation is shown at the bottom right for a field angle YAN of 5° and a field angle XAN of 0°.
  • the gradient index distribution in the GRIN element is mirror-symmetrical to the y'-z' plane
  • the transverse deviations for field angle XAN of -5° correspond to the transverse deviations for the Figure 7 shown above transverse deviations for a field angle XAN of 5 °.
  • the transverse deviations are significantly reduced.
  • the refractive index distribution of the GRIN element in this embodiment variant leads to the fact that the curvature of the GRIN element resulting aberrations in the imaging path of the virtual image can be reduced.
  • a fourth embodiment variant is shown in Figure 8.
  • the associated transverse deviations are shown in Figure 9.
  • the 3rd dimension therefore forms an angle of -15.6° with the z-axis or the main beam direction or direction of the optical axis of the imaging path of the real image of the environment (viewing direction).
  • the field angle range, the thickness 22 in the z direction and the width 23 in the y direction of the GRIN element correspond to those of the first embodiment variant.
  • the refractive index distribution in Figure 8 below has greater variations in the x' direction compared to the third embodiment variant. However, the greater tilting of the 3rd dimension results in a significant reduction in the transverse deviations, as can be seen in Figure 9.
  • the refractive index distribution of the GRIN element in this embodiment variant therefore results in the aberrations in the imaging path of the virtual imaging resulting from the curvature of the GRIN element being reduced even further.
  • the field angle range considered is 22.5° x 10°.
  • the GRIN element has a thickness 22 of 1.2mm and a width 23 of 10mm.
  • the 3rd dimension (z'-axis), in which the refractive index is constant, closes with the z-axis at one Rotation around the x-axis creates an angle of ⁇ 14°.
  • the refractive index distribution in the x'-y' plane is shown in Figure 10 below.
  • Figure 11 shows the transverse deviations that occur in this embodiment variant for field angles YAN of -5° to 5°, and for field angles XAN of 0° to 11.25°.
  • the diameter of the reference circle shown is 2 arc minutes.
  • the transverse deviations are sufficiently small even at field angles XAN greater than 5°.
  • a sixth embodiment variant is explained in more detail below with reference to Figures 12 and 13.
  • the radii of curvature of the meniscus of the GRIN element are 150mm.
  • the field angle range is 5° x 5°.
  • the GRIN element shown has a thickness of 1.0mm and a width of 15mm.
  • the refractive index distribution is shown in the bottom left of Figure 12 in the form of a cross section in an xz plane.
  • the refractive index is constant in the y direction. This means that the refractive index does not conform to the outer surfaces, i.e. the first surface and the second surface.
  • the refractive index curve on the second surface i.e. the front side 13 of the optical waveguide 20 shown in Figure 12
  • the x-axis of the diagram shows the position along the surface.
  • the respective refractive indices are plotted on the y-axis of the diagram.
  • the refractive index decreases as the y value increases, i.e. starting from the coupling surface 10 along the surface 13.
  • the transverse deviations for the sixth embodiment variant are shown schematically in Figure 13. As in the previously described embodiment variants, the diameter of the reference circle shown is 2 arc minutes.
  • a seventh embodiment variant is explained below with reference to Figures 14 to 17. In this variant, the astigmatism in the virtual image is corrected for the field angle of 5° x 5°.
  • the waveguide 20 has a thickness of 1 mm and a length of 18 mm in the area of the GRIN element.
  • the radius of curvature of the concave surface 12 of the meniscus of the GRIN element of the optical waveguide 20 is 150 mm in this embodiment variant.
  • the second surface, i.e. the convex surface 13 of the meniscus is designed as a torus.
  • the radius of curvature of the second surface 13 in the image plane Rz (radius when rotating about the x-axis) is 150.0 mm.
  • the radius of curvature perpendicular to the image plane Rx (radius when rotating around the y-axis) is 134.5 mm.
  • the astigmatism is corrected not only for the virtual image, but also for the imaging path of the image of the real environment (as seen through the waveguide).
  • the toric design of the second surface is necessary to compensate for the astigmatism that arises from the design of the waveguide as a GRIN element in the viewing direction.
  • the refractive index distribution conforms to the convex outer surface, i.e. the second surface 13. This means that the refractive index is constant on the convex outer surface, but the refractive index inside the optical waveguide increases with increasing distance from the convex outer surface. From a manufacturing perspective, this has the advantage that films with appropriate refractive indices can be arranged one on top of the other.
  • the refractive index distributions for different cutting planes are shown in Figure 14 below.
  • the diagram shown in the middle left shows the distribution in a section in an xz plane
  • the figure shown in the middle right shows a section in a yz plane
  • the figure shown below shows a section in an xy plane.
  • Figure 15 shows the transverse deviations for this embodiment variant.
  • 16 shows the spherical refractive power in an imaging path of a real image of the environment (viewing direction) in diopters of the optical waveguide 20 of the seventh embodiment variant in an xy representation.
  • the scale on the right indicates the refractive power in diopters.
  • the dimensions are plotted in mm on the x-axis and y-axis.
  • the refractive power has a value of 0.385 diopters +/-0.015 diopters.
  • the optical waveguide according to the invention therefore influences the spherical refractive power by a constant amount, which can be maintained in the push-pull concept.
  • the astigmatism in diopters is shown in the form of a diagram. The scale on the right indicates astigmatism in diopters.
  • the astigmatism when looking through the optical waveguide 20 of the seventh embodiment variant is less than 0.05 diopters (Dpt) in the marked area 24. So no compensation is required.
  • the marked area 24 in Figures 16 and 17 has the size of approximately 40mmx20mm.
  • the refractive index distribution and the convex outer surface of the optical fiber are coordinated in such a way that when looking through the optical fiber, the astigmatism is less than 0.05 D and thus the objects in the outside world are imaged practically without aberrations.
  • the spherical refractive power of the optical fiber is almost constant throughout the entire range and can easily be maintained, i.e. exploited, in a push-pull concept, for example.
  • first surface and the second surface each have a meniscus shape with different radii of curvature.
  • the first surface i.e. the concave surface facing the eye
  • the second surface i.e. the convex surface of the meniscus
  • the field angle range in this variant is 40° x 10°.
  • the refractive index distribution conforms to at least one of the outer surfaces, i.e. to the first surface and/or the second surface.
  • the GRIN element has a thickness 22 of 1.2mm and a width 23 of 12mm.
  • 18 shows the refractive index distributions in a section in an xz plane, in a section in a yz plane and in a section in an xy plane. The area shown has an extension of 10 mm in the x direction.
  • Figure 19 shows the transverse deviations for different viewing angles for this variant.
  • the diameter of the reference circle is 2 arc minutes.
  • Figure 20 shows the spherical refractive power in diopters and
  • Figure 21 shows the astigmatism in diopters as seen through the optical waveguide.
  • the dashed area 25 marks the extent of the optical waveguide in the x-direction and y-direction with a field of view of 40° x 10°.
  • the spherical refractive power of the optical waveguide is 1.3 diopters +/-0.04 diopters, which can be used when integrated into a push-pull lens.
  • the refractive power of the optical fiber can be used to correct ametropia, in particular of up to 1.3 diopters. From Figure 20 it follows that the astigmatism when viewed through the optical waveguide is less than 0.05 diopters, so no further compensation is required.
  • Figure 22 shows schematically an image display device 30 according to the invention, for example a head-mounted display, which comprises an optical arrangement 31 according to the invention.
  • the optical arrangement 31 according to the invention comprises an optical waveguide 20 according to the invention, in particular an optical waveguide according to one of the previously described embodiment variants.
  • the optical arrangement 31 also includes at least one optical element 3, 4, for example a lens.
  • the optical element 3, 4 can be designed as a push lens and/or pull lens.
  • the optical element 3, 4 can be used to correct ametropia and/or to focus a virtual image, etc. be designed.
  • image display device 30 according to the invention can only comprise an optical waveguide 20 according to the invention instead of the optical arrangement 31.
  • FIG. 23 shows schematically an image capture device 32 according to the invention, which comprises at least one optical waveguide 20 according to the invention.
  • the coupling-out device 11 is designed as a coupling-in device and the coupling-in device or coupling-in surface 10 is designed as a coupling-out device or coupling-out surface.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Lenses (AREA)

Abstract

L'invention concerne un guide d'ondes optique (20) destiné à être disposé dans le trajet optique (5) d'un agencement optique avec un dispositif (11) à des fins de couplage de sortie et/ou de couplage d'entrée d'un trajet optique d'imagerie. Le guide d'ondes optiques (20) comprend un élément GRIN possédant au moins une surface incurvée (12, 13), l'élément GRIN possédant une distribution d'indice de réfraction conçue pour réduire les aberrations, résultant de la courbure de l'élément GRIN, dans un trajet d'imagerie d'une image virtuelle créée au moyen d'ondes lumineuses guidées dans le guide d'ondes optiques (20) par réflexion interne totale.
EP23732871.1A 2022-06-14 2023-06-12 Guide d'ondes optiques possédant un élément grin incurvé Pending EP4540553A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102022114914.5A DE102022114914A1 (de) 2022-06-14 2022-06-14 Lichtwellenleiter mit gekrümmtem GRIN-Element
PCT/EP2023/065628 WO2023242111A1 (fr) 2022-06-14 2023-06-12 Guide d'ondes optiques possédant un élément grin incurvé

Publications (1)

Publication Number Publication Date
EP4540553A1 true EP4540553A1 (fr) 2025-04-23

Family

ID=86899105

Family Applications (1)

Application Number Title Priority Date Filing Date
EP23732871.1A Pending EP4540553A1 (fr) 2022-06-14 2023-06-12 Guide d'ondes optiques possédant un élément grin incurvé

Country Status (5)

Country Link
US (1) US20250362504A1 (fr)
EP (1) EP4540553A1 (fr)
CN (1) CN119317794A (fr)
DE (1) DE102022114914A1 (fr)
WO (1) WO2023242111A1 (fr)

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016113534A1 (fr) * 2015-01-12 2016-07-21 Milan Momcilo Popovich Affichage à guide d'ondes isolé de l'environnement
DE102016105060B3 (de) 2016-03-18 2017-07-06 Carl Zeiss Smart Optics Gmbh Brillenglas für eine Abbildungsoptik, Abbildungsoptik und Datenbrille
CN108152955B (zh) * 2016-12-06 2021-12-28 艾菲瑞斯特有限公司 用于近眼显示器的图像引导光学器件
WO2021146474A1 (fr) 2020-01-16 2021-07-22 Akalana Management Llc Systèmes optiques ayant des structures optiques à indice de gradient
US20230384595A1 (en) 2020-10-14 2023-11-30 University Of Rochester Curved lightguide and apparatus and methods employing a curved lightguide

Also Published As

Publication number Publication date
DE102022114914A1 (de) 2023-12-14
CN119317794A (zh) 2025-01-14
US20250362504A1 (en) 2025-11-27
WO2023242111A1 (fr) 2023-12-21

Similar Documents

Publication Publication Date Title
DE102007004444B4 (de) Multifunktions-Brillenglas, Verwendung eines solchen Multifunktions-Brillenglases in einer Datenbrille sowie Datenbrille
DE102013214700B4 (de) Brillenglas sowie Anzeigevorrichtung mit einem solchen Brillenglas
DE102015122302B4 (de) Ophthalmologisches optisches Element, Brille, kopfgetragene Anzeigevorrichtung, computerimplementiertes Verfahren zum Auslegen eines ophthalmologischen optischen Elements, Verfahren zum Herstellen eines ophthalmologischen optischen Elements sowieComputerprogrammprodukt
EP2130083B1 (fr) Système oculaire
EP3345043B1 (fr) Verre de lunetterie conçu pour un système optique de reproduction destiné à générer une image virtuelle, et procédé de production d'un tel verre de lunetterie
DE102013219623B4 (de) Brillenglas für eine auf den Kopf eines Benutzers aufsetzbare und ein Bild erzeugende Anzeigevorrichtung sowie Anzeigevorrichtung mit einem solchen Brillenglas
EP3353588A1 (fr) Optique de reproduction ainsi que dispositif d'affichage pourvu d'une telle optique de reproduction
DE102014110961B4 (de) Datenbrille
DE102014119550B4 (de) Abbildungsoptik zum Erzeugen eines virtuellen Bildes und Datenbrille
EP3132300B1 (fr) Verre de lunettes pour dispositif d'affichage positionnable sur la tête d'un utilisateur et générant une image
EP3458900A1 (fr) Verre de lunettes pour système optique de reproduction et lunettes de données
DE202014010406U1 (de) Anzeigevorrichtung
DE102007046505B4 (de) Anzeigevorrichtung und Stereo-Anzeigemodul
WO2023242111A1 (fr) Guide d'ondes optiques possédant un élément grin incurvé
WO2022106095A1 (fr) Lentille ophtalmique pour lunettes et procédé de production d'une lentille ophtalmique
DE102022102213A1 (de) Optisches System
WO2009018875A1 (fr) Ensemble hmd
DE102023134822A1 (de) Optische Anordnung mit Lichtwellenleiter zum Einstrahlen von virtuellen Bildern und Head-Mounted-Display
DE102023125130A1 (de) Brillenglas für ein Head-Mounted Display, Head-Mounted Display sowie Verfahren zum Entwerfen und Herstellen eines Brillenglases
DE102023116999A1 (de) Brillenglas, Brille, computerimplementiertes Verfahren zum Entwurf eines Brillenglases und Verfahren zum Herstellen eines Brillenglases
DE102025120170A1 (de) Optisches anzeigesystem und anzeigevorrichtung
EP2028520A2 (fr) Dispositif optique

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20241126

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)