Display having lens integrated into covering layer

Abstract

A display may include a waveguide having an output coupler that couples image light out of the waveguide and toward a lens that imparts a first power to the image light. The cover layer may have an outer surface with a three-dimensional curvature and an inner surface. A portion of the inner surface that overlaps the output coupler may have different three-dimensional curvatures that form an additional lens in the cover layer that transmits world light to the output coupler. The output coupler may transmit the world light to the lens, which transmits the world light and the image light to an eye-adapted region. The curvature of the portion of the inner surface may impart to the world light a power that inverts the first power and / or a power that imparts to the world light by the outer surface of the cover layer.

Description

[0001] This application claims priority to U.S. Patent Application No. 18 / 467,459 filed on September 14, 2023 and U.S. Provisional Patent Application No. 63 / 409,093 filed on September 22, 2022, which are hereby incorporated by reference in their entirety. Background Art

[0002] The present disclosure relates to optical systems, such as optical systems in electronic devices having displays.

[0003] An electronic device may include a display that provides an image near the user's eyes. Such electronic devices often include virtual reality or augmented reality headsets having a display with optical elements that allow the user to view the display. If care is not taken, the components used to display the image may be bulky and may not exhibit the desired level of optical performance. Summary of the invention

[0004] The electronic device may have a display system for providing image light to the eye zone. The display system may include a waveguide. The waveguide may propagate image light coupled into the waveguide from a projector. An output coupler on the waveguide may couple the image light out of the waveguide and toward a lens. The lens may impart a first optical power to the image light to provide a virtual object in the image light to the eye zone at a desired virtual image distance and / or to implement a user's corrective prescription.

[0005] The cover layer may overlap with the output coupler and the lens. The cover layer may have an outer surface and an inner surface. The outer surface may have a three-dimensional curvature. The inner surface may have a portion overlapping with the output coupler having a different three-dimensional curvature. This portion of the inner surface may form an additional lens that is integrated into the cover layer and transmits world light to the output coupler. The output coupler can transmit world light to the lens. The lens can transmit world light and image light to the eye zone. The three-dimensional curvature of the portion of the inner surface of the cover layer (the lens integrated into the cover layer) can be selected to give the world light an optical focal length that reverses the first optical focal length and / or gives the world light an optical focal length by transmitting through the outer surface of the cover layer. The cover layer may overlap with a single display or two displays (e.g., a left display and a right display) of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a diagram of an illustrative system with a display according to some embodiments.

[0007] Figure 2 is a top view of an illustrative optical system for a display having a cover layer and a waveguide with an optical coupler according to some embodiments.

[0008] Figure 3 is a top view showing how an illustrative cover layer for a display may have an integrated lens according to some embodiments.

[0009] Figure 4 are top views showing how different waveguides may be provided with different illustrative cover layers with corresponding integrated lenses according to some embodiments.

[0010] Figure 5 is a top view showing how different waveguides may share an exemplary cover layer with multiple integrated lenses according to some embodiments. DETAILED DESCRIPTION

[0011] Figure 1 The system 10 may be a head-mounted device having one or more displays. The display in the system 10 may include a near-eye display 20 mounted within a support structure (housing) 14. The support structure 14 may have the shape of a pair of glasses or goggles (e.g., a support frame), may form a housing having a helmet shape, or may have other configurations for facilitating mounting and securing components of the near-eye display 20 on the user's head or near the eyes. The near-eye display 20 may include one or more display projectors (such as projector 26 (sometimes referred to herein as display module 26)) and one or more optical systems (such as optical system 22). The projector 26 may be mounted in a support structure such as the support structure 14. Each projector 26 may emit image light 30 that is redirected toward the user's eyes at the eye zone 24 using an associated one of the optical systems 22. The image light 30 may be, for example, light that contains and / or represents a visual object such as a scene or object (e.g., modulated onto the image light using image data provided to the display module by the control circuit).

[0012] Control circuitry 16 may be used to control the operation of system 10. Control circuitry 16 may include storage and processing circuitry for the operation of system 10. Circuitry 16 may include storage devices such as hard drive storage devices, non-volatile memory (e.g., electrically programmable read-only memory configured to form a solid-state drive), volatile memory (e.g., static or dynamic random access memory), etc. The processing circuitry in control circuitry 16 may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, graphics processing units, application specific integrated circuits, and other integrated circuits. Software code may be stored on memory in circuitry 16 and run on processing circuitry in circuitry 16 to implement operations for system 10 (e.g., data acquisition operations, operations involving the use of control signals to condition components, image rendering operations that produce image content for display to a user, etc.).

[0013] The system 10 may include input-output circuitry such as an input-output device 12. The input-output device 12 may be used to allow data to be received by the system 10 from external equipment (e.g., a tethered computer, a portable device (such as a handheld device or laptop), or other electrical equipment), and to allow a user to provide user input to the head mounted device 10. The input-output device 12 may also be used to gather information about the environment in which the system 10 (e.g., the head mounted device 10) is operating. Output components in the device 12 may allow the system 10 to provide output to the user, and may be used to communicate with external electronic equipment. The input-output device 12 may include sensors and other components 18 (e.g., image sensors for acquiring images of real-world objects that are digitally merged with virtual objects on a display in the system 10, accelerometers, depth sensors, light sensors, tactile output devices, speakers, batteries, wireless communication circuits for communicating between the system 10 and external electronic devices, etc.).

[0014] Projector 26 may include a liquid crystal display, an organic light emitting diode display, a laser-based display, or other types of displays. Projector 26 may include a light source, an emissive display panel, a transmissive display panel illuminated with illumination light from the light source to generate image light, a reflective display panel illuminated with illumination light from the light source to generate image light 30 (such as a digital micromirror display (DMD) panel and / or a liquid crystal on silicon (LCOS) display panel), etc.

[0015] Optical system 22 may form a lens that allows a viewer (see, e.g., the viewer's eye at eye zone 24) to view images on display 20. There may be two optical systems 22 associated with the user's respective left and right eyes (e.g., to form a left lens and a right lens). A single display 20 may produce images for both eyes, or a pair of displays 20 may be used to display images. In a configuration with multiple displays (e.g., a left-eye display and a right-eye display), the focal length and position of the lenses formed by system 22 may be selected so that any gaps that exist between the displays will not be visible to the user (e.g., so that the images of the left and right displays overlap or merge seamlessly).

[0016] If desired, optical system 22 may include components (e.g., optical combiners, etc.) to allow real-world image light from a real-world image or object (e.g., real-world object 28) to be optically combined with a virtual (computer-generated) image, such as a virtual image in image light 30. In this type of system (sometimes referred to as an augmented reality system), a user of system 10 may view both real-world content and computer-generated content overlaid on top of the real-world content. Camera-based augmented reality systems may also be used in device 10 (e.g., in an arrangement where a camera captures real-world images of external objects and digitally merges such content with virtual content at optical system 22).

[0017] If desired, system 10 may include wireless circuitry and / or other circuitry to support communications with a computer or other external equipment (e.g., a computer that supplies image content to display 20). During operation, control circuitry 16 may provide image content to display 20. The content may be received remotely (e.g., from a computer or other content source coupled to system 10) and / or may be generated by control circuitry 16 (e.g., text, other computer-generated content, etc.). The content provided to display 20 by control circuitry 16 may be viewed by a viewer at eye zone 24.

[0018] Figure 2 is available in Figure 1 A top view of an exemplary display 20 for use in the system 10 of FIG. Figure 2 As shown, display 20 may include a projector such as projector 26 and an optical system such as optical system 22. Optical system 22 may include optical elements such as one or more waveguides 32. Waveguide 32 may include one or more stacked substrates (e.g., stacked planar and / or curved layers, sometimes referred to herein as "waveguide substrates") formed of optically transparent materials such as plastics, polymers, glass, etc.

[0019] If desired, the waveguide 32 may also include one or more layers of a holographic recording medium (sometimes referred to herein as a "holographic medium", "grating medium" or "diffraction grating medium") on which one or more diffraction gratings (e.g., holographic phase gratings, sometimes referred to herein as "holograms", surface relief gratings, etc.) are recorded. The holographic recording may be stored as an optical interference pattern (e.g., alternating regions of different refractive indices) within a photosensitive optical material such as a holographic medium. The optical interference pattern may produce a holographic phase grating that, when illuminated with a given light source, diffracts light to produce a three-dimensional reconstruction of the holographic recording. The holographic phase grating may be a non-switchable diffraction grating encoded with a permanent interference pattern, or may be a switchable diffraction grating in which the diffracted light may be modulated by controlling an electric field applied to the holographic recording medium. If desired, multiple holographic phase gratings (holograms) may be recorded within the same volume of holographic medium (e.g., superimposed within the same volume of grating medium). The holographic phase grating may be, for example, a volume hologram or a thin film hologram in a grating medium. The grating medium may include a photopolymer, a gelatin such as dichromated gelatin, a silver halide, a holographic polymer dispersed liquid crystal, or other suitable holographic medium.

[0020] The diffraction grating on the waveguide 32 may include a holographic phase grating such as a volume hologram or a thin film hologram, a meta-grating, or any other desired diffraction grating structure. The diffraction grating on the waveguide 32 may also include a surface relief grating (SRG) formed on one or more surfaces of a substrate in the waveguide 32 (e.g., as a modulation of the thickness of an SRG dielectric layer), a grating formed by a pattern of a metal structure, etc. The diffraction grating may, for example, include a plurality of multiplexed gratings (e.g., holograms) at least partially overlapping within the same volume of grating medium (e.g., for diffracting light of different colors and / or light from different input angle ranges at one or more corresponding output angles). If desired, other light redirecting elements such as louvered mirrors may be used in place of the diffraction grating in the waveguide 32.

[0021] like Figure 2 As shown, projector 26 can generate (e.g., produce and emit) image light 30 associated with image content to be displayed to eye zone 24 (e.g., image light 30 can convey a series of image frames for display at eye zone 24). If desired, image light 30 can be collimated using a collimating lens in projector 26. Optical system 22 can be used to present image light 30 output from projector 26 to eye zone 24. If desired, projector 26 can be mounted on Figure 1 The optical system 22 may be mounted within the support structure 14, and the optical system 22 may be mounted between portions of the support structure 14 (e.g., to form a lens aligned with the eye area 24). Other mounting arrangements may be used if desired.

[0022] The optical system 22 may include one or more optical couplers (eg, light redirecting elements) such as an input coupler 34, a cross coupler 36, and an output coupler 38. Figure 2 In the example of FIG. 3 , the input coupler 34, the cross coupler 36, and the output coupler 38 are formed at or on the waveguide 32. The input coupler 34, the cross coupler 36, and / or the output coupler 38 may be completely embedded in the base layer of the waveguide 32, may be partially embedded in the base layer of the waveguide 32, may be mounted to the waveguide 32 (e.g., mounted to the outer surface of the waveguide 32), etc.

[0023] The waveguide 32 may guide the image light 30 along its length via total internal reflection. The input coupler 34 may be configured to couple the image light 30 from the projector 26 into the waveguide 32 (e.g., within the total internal reflection (TIR) ​​range of the waveguide, where the light propagates along the waveguide via TIR), while the output coupler 38 may be configured to couple the image light 30 from within the waveguide 32 (e.g., propagating within the TIR range) to the outside of the waveguide 32 and toward the eye zone 24 (e.g., at an angle outside the TIR range). The input coupler 34 may include an input coupling prism, an edge or face of the waveguide 32, a lens, a turning mirror or liquid crystal turning element, a diffraction grating structure (e.g., a volume hologram, SRG, etc.), a partially reflective structure (e.g., a louvered mirror), or any other desired input coupling element.

[0024] For example, the projector 26 may emit image light 30 in the +Y direction toward the optical system 22. When the image light 30 strikes the input coupler 34, the input coupler 34 may redirect the image light 30 so that the light propagates within the waveguide 32 toward the output coupler 38 (e.g., in the +X direction within the TIR range of the waveguide 32) via total internal reflection. When the image light 30 strikes the output coupler 38, the output coupler 38 may redirect the image light 30 out of the waveguide 32 toward the eye zone 24 (e.g., rearward along the Y axis). In a specific implementation where the cross-coupler 36 is formed on the waveguide 32, the cross-coupler 36 may redirect the image light 30 in one or more directions as it propagates down the length of the waveguide 32 (e.g., from a propagation direction coupled into the waveguide by the input coupler toward the output coupler 38). When redirecting the image light 30, the cross-coupler 36 may also perform pupil expansion on the image light 30 in one or more directions. In expanding the pupil of the image light, the cross-coupler 36 can, for example, help reduce the vertical size (e.g., in the Z direction) of the waveguide 32 relative to an implementation that omits the cross-coupler 36. Therefore, the cross-coupler 36 is sometimes also referred to herein as a pupil expander 36 or an optical expander 36. If desired, the output coupler 38 can also expand the image light 30 when coupling the image light out of the waveguide 32.

[0025] The input coupler 34, the cross coupler 36, and / or the output coupler 38 may be based on reflective and refractive optics, or may be based on diffractive (e.g., holographic) optics. In an arrangement where the couplers 34, 36, and 38 are formed by reflective and refractive optics, the couplers 34, 36, and 38 may include one or more reflectors (e.g., arrays of micromirrors, partial mirrors, shutter mirrors, or other reflectors). In an arrangement where the couplers 34, 36, and 38 are based on diffractive optics, the couplers 34, 36, and 38 may include a diffraction grating (e.g., a volume hologram, a surface relief grating, etc.).

[0026] Figure 2 The examples are merely illustrative. The optical system 22 may include a plurality of waveguides stacked laterally and / or vertically relative to each other. Each waveguide may include one, two, all, or none of the couplers 34, 36, and 38. If desired, the waveguide 32 may be at least partially curved or bent. One or more of the couplers 34, 36, and 38 may be omitted. If desired, the optical system 22 may include a single optical coupler (sometimes referred to herein as an interleaved coupler, a diamond coupler, or a diamond expander) that performs the operations of both the cross coupler 36 and the output coupler 38, or the cross coupler 36 may be separated from the output coupler 38.

[0027] Image light 30 may include an image of a virtual object, sometimes referred to herein as a virtual object image or simply a virtual object. Projector 26 may receive image data including the virtual object image (e.g., pixels forming the image data at different pixel locations of the virtual object image). Output coupler 38 may be used to overlay the virtual object image with world light 48 from real-world objects 28 within the field of view (FOV) of eyepiece zone 24. Control circuitry of system 10 may provide image data to projector 26, which places the virtual object image at a desired location within the FOV at eyepiece zone 24 (e.g., such that the virtual object image overlaps a desired real-world object in a scene / environment in front of system 10).

[0028] If desired, the optical system 22 may include one or more lenses 39 that overlap with the output coupler 38 (e.g., an optical combiner on the waveguide 32). For example, the optical system 22 may include at least a first lens 39A and a second lens 39B. Lens 39B may be interposed between the waveguide 32 and the real-world object 28 (sometimes referred to herein as an external object 28). Lens 39A may be interposed between the waveguide 32 and the eyepiece 24. Lens 39 is transparent and allows world light 48 from the real-world object 28 to pass to the eyepiece 24 for viewing by the user. At the same time, the user can view the virtual object image (in the image light 30) that is guided out of the waveguide 32 and reaches the eyepiece 24 through lens 39A.

[0029] The strength of lens 39A (sometimes referred to as optical power, power, or diopter) can be selected to place the virtual object image in image light 30 at a desired image distance (depth) from eye zone 24 (sometimes referred to herein as virtual object distance, virtual object image distance, virtual image distance (VID), virtual object depth, virtual image depth, or image depth). For example, it may be desirable to place a virtual object (virtual object image) such as text, icons, moving images, characters, effects, or other content or features at a certain virtual image distance (e.g., to integrate the virtual object image within, on, in, or around a real-world object in front of system 10). The placement of the virtual object at this distance can be achieved by appropriately selecting the strength of lens 39A. Lens 39A can be a negative lens for users whose eyes do not have refractive errors. Therefore, the strength of lens 39A (larger net negative optical power) can be selected to adjust the distance (depth) of the virtual object. Therefore, lens 39A may sometimes be referred to herein as bias lens 39A or bias (B-) lens 39A.

[0030] If desired, lens 39B may have a complementary power value (e.g., a positive power whose magnitude matches the magnitude of the negative power of lens 39A). Thus, lens 39B may sometimes be referred to herein as a bias + (B+) lens 39B, a complementary lens 39B, or a compensating lens 39B. For example, if lens 39A has a power of -2.0 diopters, lens 39B may have an equal and opposite power of +2.0 diopters (as an example). In this type of arrangement, the positive power of lens 39B cancels out the negative power of lens 39A. Thus, the total power of lenses 39A and 39B together would be 0 diopters. For example, a real-world object 28 located far from system 10 (effectively at infinity) may be viewed as if lenses 39A and 39B were not present. This allows a viewer to view real-world objects such as real-world object 28 without the optical influence from lenses 39A and 39B, while placing virtual objects at the desired VID.

[0031] For a user with satisfactory uncorrected vision, this type of complementary lens arrangement thus allows virtual objects to be placed in close proximity to the user (e.g., at a virtual image distance of 0.5m to 5m, at least 0.1m, at least 1m, at least 2m, less than 20m, less than 10m, less than 5m, or other suitable near-intermediate distance from device 10) while allowing the user to view real-world objects without modification by the optical components of the optical system. For example, a real-world object located at a distance of 2m from eye zone 24 (e.g., a real-world object marked by a virtual text label at a virtual image distance of 2m) will optically appear to be located 2m from eye zone 24. This is merely illustrative, and if desired, lenses 39A and 39B need not be complementary lenses (e.g., lenses 39A and 39B may have any desired optical power).

[0032] In addition, some users may need vision correction. Vision correction can be provided using tunable lenses, fixed (e.g., removable) lenses (sometimes referred to as supplemental lenses, vision correction lenses, removable lenses, or clip-on lenses) and / or by adjusting the optical power of lens 39A and / or lens 39B to achieve the desired vision correction. Generally speaking, the vision correction imparted to the lenses may include correction of refractive errors (eyes with refractive errors), such as lenses that correct myopia (nearsightedness), correction for hyperopia (hyperopia), correction for astigmatism, correction for skewed vision, help adapt to the age-related decrease in the range of accommodation exhibited by the eyes (sometimes referred to as presbyopia), and / or correction of other vision impairments.

[0033] Lenses 39A and 39B can have any desired optical power and any desired shape (e.g., can be plano-convex lenses, plano-concave lenses, flat free-form lenses, free-form convex lenses, free-form concave lenses, convex-concave lenses, etc.). Specific implementations in which the optical power of lenses 39A and / or 39B is fixed (e.g., at the time of manufacture) are described herein as examples. If desired, one or both of lenses 39A and / or 39B can be electrically adjustable to impart different optical powers or optical power distributions over time (e.g., lenses 39A and / or 39B can be adjustable / tunable liquid crystal lenses). If desired, lens 39A can have different regions with different optical powers or focal lengths to provide virtual object images at different VIDs in different regions of the eye-adaptive zone 24. Lens 39B can have different regions with optical powers or focal lengths that are opposite to the optical power or focal length of lens 39A.

[0034] If desired, display 20 may be provided with a cover layer, such as cover layer 40. Cover layer 40 may overlap optical system 22 on the world-facing side of system 10 (e.g., cover layer 40 may be interposed between waveguide 32 and real-world object 28). Cover layer 40 may have a first (outer or exterior) surface 42 facing real-world object 28 and an opposing second (inner or interior) surface 44 facing waveguide 32. Surface 44 may be separated from waveguide 32 by a distance (gap) 46. Lens 39B may be interposed between waveguide 32 and cover layer 40 within distance 46.

[0035] The cover layer 40 may be a transparent member that passes the world light 48 to the output coupler 38. The cover layer 40 may be formed of a dielectric material such as a plastic. If desired, the cover layer 40 may form part of a housing for the system 10 or may be integral with the housing of the system. The cover layer 40 may be fixed in place on the display 20 or may be removable if desired. The cover layer 40 may contribute to the aesthetic / aesthetic appearance of the system 10 while also serving to protect the waveguide 32 from contamination or damage during operation.

[0036] like Figure 2 As shown, world light 48 can be transmitted through cover layer 40 to lens 39B, which transmits world light 48 to output coupler 38, which transmits world light 48 to lens 39A while transmitting world light 48 to eye zone 24 (e.g., overlapping with virtual objects in image light 30). Surface 42 of cover layer 40 can have a non-zero curvature that is selected to optimize the aesthetic / aesthetic appearance and / or tactile experience of system 10. The curvature of surface 42 can be a two-dimensional curvature (e.g., about a single axis) or a three-dimensional curvature (e.g., about two or more non-parallel axes). The curvature of surface 42 can be, for example, a free-form surface or a deformable surface.

[0037] Surface 44 of cover layer 40 may also have a non-zero curvature. The curvature of surface 44 may be a two-dimensional curvature (e.g., about a single axis) or a three-dimensional curvature (e.g., about two or more non-parallel axes). The curvature of surface 44 may be, for example, a free-form surface or a deformed surface. The curvature of surface 44 may be selected so that some or all of surface 44 extends parallel to the overlapping portion of surface 42 to minimize the thickness of cover layer 40 and therefore minimize the weight and volume of cover layer 40, minimize or maximize distance 46, ensure that cover layer 40 exhibits a desired amount of mechanical integrity, and / or compensate for the refractive effect (e.g., optical power) of surface 42 on world light 48.

[0038] For example, the curvature of surface 42 imparts optical power to the transmitted light. Thus, the curvature of surface 42 may impart a non-zero optical power to world light 48 when transmitted through surface 42 of cover layer 40 (e.g., a non-zero optical power that is different at different points on the surface based on the curvature of the surface). If desired, the curvature of surface 44 may be selected to present an opposite optical power (e.g., a non-zero optical power that is different at different points on the surface based on the curvature of the surface) such that, when transmitted through surface 44, the curvature of surface 44 reverses any optical power imparted to world light 48 by transmitting through surface 42. Additionally or alternatively, lens 39B may have a lens profile (curvature in one or more lens surfaces) that is selected such that, after transmission through lens 39B, lens 39B reverses any optical power imparted to world light 48 by transmitting through surface 42 and / or surface 44 (e.g., in addition to pre-reversing the effect of lens 39A on world light 48).

[0039] In displays such as display 20, space is at a premium. Using lens 39B to operate on world light 48 may consume excess space within device 10 (e.g., at least distance 46) and may unnecessarily increase the complexity and cost of device 10. In addition, lens 39B may become damaged or misaligned during the operational life of system 10. To alleviate these issues, surface 44 of cover layer 40 may be curved to perform refractive operation of lens 39B on world light 48 (e.g., to impart the same optical power to world light 48 as lens 39B), thereby allowing lens 39B to be omitted from system 10. This may be used to minimize distance 46, and therefore minimize the volume of display 20, to reduce the complexity and cost of system 10, and / or to enhance the mechanical robustness of system 10 during its operational life.

[0040] Figure 3 4 is a top view showing how cover layer 40 may be curved to perform the refractive operation of lens 39B on world light 48. Figure 4As shown, a portion (region or area) 50 of surface 44 of cover layer 40 can overlap output coupler 38 and eye region 24. If desired, the curvature of portion 50 can be different from the curvature of the remainder of surface 44 outside portion 50. The curvature of portion 50 of surface 44 can be a free-form curvature, an anamorphic curvature, or a curvature selected to position lens 39B ( Figure 2 ) into other curvatures in the cover layer 40 itself (eg, the cover layer 40 may form Figure 2 This may, for example, configure the cover layer 40 to form a lens 52 (eg, a thicker or protruding curved portion of the cover layer) that overlaps the output coupler 38.

[0041] The curvature of portion 50 of surface 44 of cover layer 40 (e.g., the curvature of lens 52 in cover layer 40) may, for example, be selected to both perform the operation of lens 39B and to reverse the optical effect of surface 42 on world light 48. In other words, the curvature of portion 50 of surface 44 may, for example, include a first curvature selected to reverse the optical effect of surface 42 on world light 48, which is different from the curvature selected to perform Figure 2 A second curvature is superimposed upon (then upon) the optical effect of lens 39B (e.g., to reverse the optical power imparted by lens 39A to world light 48, which places virtual objects in image light 30 at a desired image distance from the eye zone).

[0042] For example, Figure 3 As shown, world light 48 from external object 28 (e.g., emitted or reflected by external object 28) may be incident on cover layer 40 of display 20. World light 48 may be transmitted through surface 42 of cover layer 40. The curvature (e.g., a three-dimensional free-form curvature) of surface 42 (e.g., as selected to optimize the aesthetic and tactile experience of system 10) may manipulate (e.g., refract) the transmitted world light 48 (e.g., by imparting an optical power corresponding to the curvature), thereby generating world light 48' within cover layer 40.

[0043] World light 48' may pass through cover layer 40 and may be transmitted through portion 50 of surface 44 of cover layer 40. The curvature (e.g., a three-dimensional free-form curvature or a deformed curvature) of portion 50 of surface 44 (e.g., lens 52) may reverse the optical effect (refraction) produced on the world light by transmitting through surface 42. The curvature of portion 50 of surface 44 (lens 52) may simultaneously perform Figure 239A). In other words, the curvature of portion 50 of surface 44 (lens 52) may also reverse a subsequent optical effect (refraction) that would be produced on the world light by transmission through lens 39A (e.g., reversing the effect of lens 39A on the world light as needed to place a virtual object in image light 30 at a desired VID from eye zone 24 and / or to incorporate a user's vision correction prescription). In this way, portion 50 of surface 44 of cover layer 40 (e.g., lens 52) may impart an optical power to world light 48' that reverses (compensates for) both the optical power produced by surface 42 and the optical power produced by lens 39A to produce (transmit) world light 48" toward waveguide 32.

[0044] The output coupler 38 can receive and transmit world light 48' (e.g., undiffract world light). The output coupler 38 can transmit world light 48" out of the waveguide 32 and toward the lens 39A, while coupling (e.g., diffracting) the image light 30 out of the waveguide 32 and toward the lens 39A. The lens 39A can transmit the image light 30 while imparting its corresponding optical focal length to the image light 30 to place a virtual object at a desired VID from the eye-adaptive zone 24 and / or incorporate the user's vision correction prescription. The lens 39A can also simultaneously transmit world light 48", while imparting its corresponding optical focal length to the image light 48. Since the world light has been pre-compensated by the lens 52 in the cover layer 50 for the optical focal length of the lens 39A, the optical focal length of the lens 39A can reverse the optical focal length imparted to the world light by the lens 52 in the cover layer 50, thereby restoring the original world light 48 received at the cover layer 40, which is then transmitted to the eye-adaptive zone 24.

[0045] In this way, lens 52 in cover layer 40 (e.g., the curvature of portion 50 of surface 44) can effectively mitigate the optical effects on world light 48 produced by both the curvature of surface 42 of cover layer 40 and lens 39A, thereby allowing undistorted world light to be received at the eye zone. By forming lens 52 within cover layer 40 itself, the need for a lens 52 to be removed can be eliminated. Figure 2 The lens 39B is provided so as to reduce the distance between the cover layer 40 and the waveguide 32 to a reduced distance 46' (eg, to help make the system 10 as compact and robust as possible).

[0046] If desired, system 10 may include a different respective cover layer 40 for each of displays 20 (eg, left and right displays 20 ) in system 10 . Figure 4 is a top view illustrating one example of how system 10 may include a different respective cover layer 40 for each of displays 20 in system 10 .

[0047] like Figure 4As shown, the system 10 may include a first projector 26-1 that provides a first image light 30-1 to a first waveguide 32-1, which guides the first image light 30-1 to a first eye zone 24-1 (e.g., a left eye zone) through a first lens 39A-1 (e.g., for a first display or a left display 20 in the system 10). The system 10 may also include a second projector 26-2 that provides the first image light 30-2 to a second waveguide 32-2, which guides the second image light 30-2 to a second eye zone 24-2 (e.g., a right eye zone) through a second lens 39A-2 (e.g., for a second display or a right display 20 in the system 10).

[0048] System 10 may include a first cover layer 40-1 covering (overlapping) waveguide 32-1, lens 39A-1, and eye zone 24-1 (e.g., first display). First cover layer 40-1 may include lens 52 formed by the curvature of portion 50 of surface 44 of first cover layer 40-1 (e.g., where portion 50 overlaps eye zone 24-1). Lens 52 may invert the optical effect of surface 42 of first cover layer 40-1, and may invert the subsequent optical effect of lens 39A-1 on world light 48 transmitted through first cover layer 40-1 to eye zone 24-1.

[0049] like Figure 4 As shown, the system 10 can also include a second cover layer 40-2 covering (overlapping) the waveguide 32-2, the lens 39A-2, and the eye zone 24-2 (e.g., a second display). The second cover layer 40-2 can be separate from the first cover layer 40-1 (e.g., can be formed by a separate transparent material sheet). The second cover layer 40-2 can include a lens 52 formed by the curvature of a portion 50 of a surface 44 of the second cover layer 40-2 (e.g., where the portion 50 overlaps the eye zone 24-2). The lens 52 can reverse the optical effect of the surface 42 of the second cover layer 40-2, and can reverse the subsequent optical effect of the lens 39A-2 on the world light 48 transmitted through the second cover layer 40-2 to the eye zone 24-2.

[0050] Figure 4 The example of is merely illustrative. In other specific implementations, a single cover layer 40 can cover both the left display and the right display of the system 10. Figure 5 is a top view showing one example of how a single cover layer 40 may cover both the left and right displays of system 10 .

[0051] like Figure 5As shown, system 10 may include a single (shared or common) cover layer 40 covering (overlapping) two waveguides 32-1 and 32-2, two lenses 39A-1 and 39A-2, and two eye zones 24-1 and 24-2. Cover layer 40 may include a first lens 52-1 formed by the curvature of a first portion 50-1 of a surface 44 of cover layer 40 (e.g., where lens 52-1 and portion 50-1 overlap waveguide 32-1, lens 39A-1, and eye zone 24-1). Lens 52-1 may invert the optical effect of surface 42 of cover layer 40, and may invert the subsequent optical effect of lens 39A-1 on world light 48 transmitted through cover layer 40 to eye zone 24-1.

[0052] Cover layer 40 may also include a second lens 52-2 formed by the curvature of a second portion 50-2 of surface 44 of cover layer 40 (e.g., where lens 52-2 and portion 50-2 overlap waveguide 32-2, lens 39A-2, and eyepiece zone 24-2). Lens 52-2 may invert the optical effect of surface 42 of cover layer 40, and may invert the subsequent optical effect of lens 39A-2 on world light 48 transmitted through cover layer 40 to eyepiece zone 24-2.

[0053] By integrating the lens into the cover layer 40, the volume, weight, thickness, cost, number of parts, and manufacturing complexity of the system 10 can be minimized without sacrificing optical performance. Figure 2 ) is also used to minimize the number of reflective surfaces (e.g., surfaces that can reflect at least some world light 48 and / or image light 30) in the optical path, thereby helping to minimize ghost artifacts at the eye zone.

[0054] According to one embodiment, an electronic device is provided, comprising: a waveguide configured to propagate a first light; a cover layer overlapping the waveguide; an output coupler located on the waveguide; a first lens integrated into the cover layer and overlapping the output coupler, the first lens being configured to transmit a second light from an external object toward the output coupler; and a second lens being configured to couple the first light out of the waveguide and toward the second lens, and being configured to transmit the second light toward the second lens.

[0055] According to another embodiment, the cover layer has a first surface facing the waveguide and a second surface opposite the first surface, the second surface being curved.

[0056] According to another embodiment, the second surface has a three-dimensional curvature.

[0057] According to another embodiment, the three-dimensional curvature imparts the first optical power to the second light, and the lens is configured to reverse the first optical power imparted by the three-dimensional curvature to the second light.

[0058] According to another embodiment, the second lens is configured to impart a second optical power to the second light, and the lens is further configured to reverse the second optical power imparted by the second lens to the second light.

[0059] According to another embodiment, the first surface is curved.

[0060] According to another embodiment, the lens includes a portion of the first surface overlapping the output coupler and having an additional three-dimensional curvature.

[0061] According to another embodiment, the additional three-dimensional curvature of the portion of the first surface is different from the curvature of the first surface outside the portion.

[0062] According to another embodiment, the additional three-dimensional curvature comprises a free-form curvature.

[0063] According to another embodiment, the additional three-dimensional curvature comprises a deformation curvature.

[0064] According to another embodiment, the second lens is configured to impart optical power to the second light, and the lens is configured to reverse the optical power imparted by the second lens to the second light.

[0065] According to another embodiment, the electronic device includes: an additional waveguide configured to propagate a third light; an additional covering layer separated from the covering layer and overlapping with the additional waveguide; an additional output coupler located on the waveguide; a third lens integrated into the additional covering layer and overlapping with the additional output coupler, the third lens configured to transmit a second light from an external object toward the additional output coupler; and a fourth lens, the additional output coupler configured to couple the third light out of the additional waveguide and toward the fourth lens, and configured to transmit the second light toward the fourth lens.

[0066] According to another embodiment, the first lens is configured to pre-compensate the second light for a first optical power imparted to the second light by the second lens, and the third lens is configured to pre-compensate the second light for a second optical power imparted to the second light by the fourth lens.

[0067] According to one embodiment, an electronic device is provided, which includes: a lens; a waveguide configured to propagate a first light; an optical coupler located on the waveguide and configured to couple the first light out of the waveguide and toward the lens; and a covering layer having a first surface away from the waveguide and having a second surface opposite to the first surface, the first surface having a first curvature, a portion of the second surface overlapping with an output coupler having a second curvature, and the second surface having a third curvature different from the second curvature outside the portion, the covering layer being configured to transmit a second light toward the waveguide through the portion of the second surface, the output coupler being configured to transmit the second light toward the lens, and the lens being configured to transmit the first light and the second light.

[0068] According to another embodiment, the first curvature is a first three-dimensional curvature and the second curvature is a second three-dimensional curvature different from the first three-dimensional curvature.

[0069] According to another embodiment, the second three-dimensional curvature comprises a free-form curvature.

[0070] According to another embodiment, wherein the second light is received at the first surface of the covering layer, the first surface of the covering layer imparts a first optical focal length to the second light, the lens is configured to impart a second optical focal length to the second light, and the second curvature configures the portion of the second surface to impart a third optical focal length to the second light that reverses the first optical focal length and the second optical focal length.

[0071] According to another embodiment, the cover layer is thicker at the portion of the second surface than around the portion of the second surface.

[0072] According to one embodiment, an electronic device is provided, the electronic device comprising: a first waveguide configured to guide a first light toward a first lens; a second waveguide configured to guide a second light toward a second lens; a covering layer overlapping the first waveguide, the second waveguide, the first lens, and the second lens; and a third lens integrated into the covering layer and overlapping the first waveguide and the first lens, the third lens being configured to transmit a third light from an external object toward the first waveguide and being configured to reverse a first optical focal length imparted to the third light by the first lens; and a fourth lens integrated into the covering layer and overlapping the second waveguide and the second lens, the fourth lens being configured to transmit a third light toward the second waveguide and being configured to reverse a second optical focal length imparted to the third light by the second lens.

[0073] According to another embodiment, the covering layer has a first surface with a first three-dimensional curvature and a second surface opposite to the first surface, the third lens includes a first portion of the second surface having a second three-dimensional curvature different from the first three-dimensional curvature, and the fourth lens includes a second portion of the second surface having a third three-dimensional curvature different from the first three-dimensional curvature.

[0074] The foregoing is merely illustrative and various modifications may be made to the embodiments described. The foregoing embodiments may be implemented individually or in any combination.

Claims

1. An electronic device, comprising: a waveguide configured to propagate a first light; a cover layer, the cover layer overlapping the waveguide; an output coupler, the output coupler being located on the waveguide; a first lens integrated into the cover layer and overlapping the output coupler, the first lens being configured to transmit second light from an external object toward the output coupler; as well as a second lens, wherein the output coupler is configured to couple the first light out of the waveguide and towards the second lens, and is configured to transmit the second light towards the second lens. 2 . The electronic device according to claim 1 , wherein the cover layer has a first surface facing the waveguide and a second surface opposite to the first surface, the second surface being curved. The electronic device of claim 2 , wherein the second surface has a three-dimensional curvature. 4 . The electronic device of claim 3 , wherein the three-dimensional curvature imparts a first optical power to the second light, and the lens is configured to reverse the first optical power imparted by the three-dimensional curvature to the second light. 5 . The electronic device of claim 4 , wherein the second lens is configured to impart a second optical power to the second light, and the lens is further configured to reverse the second optical power imparted by the second lens to the second light. The electronic device of claim 3 , wherein the first surface is curved. 7 . The electronic device of claim 6 , wherein the lens comprises a portion of the first surface overlapping the output coupler and having an additional three-dimensional curvature. 8 . The electronic device of claim 7 , wherein the additional three-dimensional curvature of the portion of the first surface is different from a curvature of the first surface outside of the portion.

9. The electronic device of claim 7, wherein the additional three-dimensional curvature comprises a free-form curvature.

10. The electronic device of claim 7, wherein the additional three-dimensional curvature comprises a deformation curvature. 11 . The electronic device of claim 1 , wherein the second lens is configured to impart optical power to the second light, and the lens is configured to reverse the optical power imparted by the second lens to the second light.

12. The electronic device according to claim 1, further comprising: an additional waveguide configured to propagate a third light; an additional cover layer, the additional cover layer being separate from the cover layer and overlapping the additional waveguide; an additional output coupler, the additional output coupler being located on the waveguide; a third lens integrated into the additional cover layer and overlapping the additional output coupler, the third lens being configured to transmit the second light from the external object toward the additional output coupler; as well as a fourth lens, wherein the additional output coupler is configured to couple the third light out of the additional waveguide and towards the fourth lens, and is configured to transmit the second light towards the fourth lens.

13. An electronic device according to claim 12, wherein the first lens is configured to pre-compensate the second light for a first optical focal length imparted to the second light by the second lens, and the third lens is configured to pre-compensate the second light for a second optical focal length imparted to the second light by the fourth lens.

14. An electronic device comprising: lens; a waveguide configured to propagate a first light; an optical coupler located on the waveguide and configured to couple the first light out of the waveguide and toward the lens; as well as a cover layer having a first surface remote from the waveguide and having a second surface opposite to the first surface, wherein The first surface has a first curvature, A portion of the second surface overlapping the output coupler has a second curvature, the second surface has, outside the portion, a third curvature different from the second curvature, the cover layer being configured to transmit second light through the portion of the second surface toward the waveguide, The output coupler is configured to transmit the second light toward the lens, and the lens is configured to transmit the first light and the second light. 15 . The electronic device of claim 14 , wherein the first curvature is a first three-dimensional curvature, and the second curvature is a second three-dimensional curvature different from the first three-dimensional curvature.

16. The electronic device of claim 15, wherein the second three-dimensional curvature comprises a free-form curvature.

17. An electronic device according to claim 14, wherein the second light is received at the first surface of the covering layer, the first surface of the covering layer imparts a first optical focal length to the second light, the lens is configured to impart a second optical focal length to the second light, and the second curvature configures the portion of the second surface to impart a third optical focal length to the second light that reverses the first optical focal length and the second optical focal length. 18 . The electronic device of claim 14 , wherein the cover layer is thicker at the portion of the second surface than around the portion of the second surface.

19. An electronic device comprising: a first waveguide configured to direct the first light toward the first lens; a second waveguide configured to direct a second light toward a second lens; a cover layer, the cover layer overlapping the first waveguide, the second waveguide, the first lens, and the second lens; a third lens integrated into the cover layer and overlapping the first waveguide and the first lens, wherein the third lens is configured to transmit third light from an external object toward the first waveguide and is configured to reverse a first optical power imparted to the third light by the first lens; as well as a fourth lens integrated into the cover layer and overlapping the second waveguide and the second lens, wherein the fourth lens is configured to transmit the third light toward the second waveguide and is configured to reverse a second optical power imparted to the third light by the second lens.

20. An electronic device according to claim 19, wherein the covering layer has a first surface with a first three-dimensional curvature and a second surface opposite to the first surface, wherein the third lens includes a first portion of the second surface having a second three-dimensional curvature different from the first three-dimensional curvature, and wherein the fourth lens includes a second portion of the second surface having a third three-dimensional curvature different from the first three-dimensional curvature.

Images