System and method for optical alignment

Abstract

A display device can include first and second display modules that provide image light to first and second waveguides. The waveguides can direct the image light to first and second eyeboxes. Each display module can include an optical device mounted to a housing and a mechanical alignment structure that mechanically adjusts a position of an optical axis of the optical device. The alignment structure can rotate the entire housing, mechanically translate the optical device, adjust a position of a spatial light modulator within the module, and / or a control circuit can change a subset of pixels used by the modulator to compensate for optical misalignment between the first and second eyeboxes. The device can include an optical misalignment sensor that detects the optical misalignment. The control circuit can compensate for the optical misalignment as detected by the optical misalignment sensor.

Description

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 119,507, filed November 30, 2020, the entire contents of which are incorporated herein by reference. Background Technology

[0002] This disclosure relates in general to optical systems, and more specifically to optical systems for displays.

[0003] Electronic devices may include displays that present images to a user's eyes. For example, devices such as virtual reality and augmented reality headsets may include displays with optical elements that allow users to view the display.

[0004] Designing devices like these can be challenging. If not handled carefully, the components used to display content can be unsightly and bulky, and may not exhibit the expected level of optical performance. Summary of the Invention

[0005] Electronic devices such as head-mounted displays may have one or more near-eye displays that generate images for the user. A head-mounted display may be a pair of virtual reality glasses or an augmented reality headset, which allows an observer to view both computer-generated images and real-world objects in the observer's surrounding environment.

[0006] The device may include a first display module and a second display module. The first and second display modules may provide image light to corresponding first and second waveguides. The first and second waveguides may guide the image light to a first eye box and a second eye box. Each display module may include a collimating optics mounted to a housing of the display module. The collimating optics may transmit image light along an optical axis. The display module may include a mechanical alignment structure that mechanically adjusts the position of the optical axis relative to the corresponding waveguide.

[0007] For example, the mechanical alignment structure can rotate the entire display module housing to rotate the optical axis about at least one axis. The mechanical alignment structure may additionally or alternatively include a piezoelectrically driven flexure stage for mounting collimating optics to the display module housing. The piezoelectrically driven flexure stage can mechanically translate the collimating optics relative to the display module housing and thus mechanically translate the optical axis (e.g., about one or both axes). The mechanical alignment structure may additionally or alternatively adjust the position and / or orientation of the spatial light modulator within the display module housing. These mechanical adjustments to the optical axis can be used to compensate for optical misalignment between the first and second eye-friendly zones, thereby ensuring that the user experiences satisfactory binocular vision when viewing both the first and second eye-friendly zones. Control circuitry may additionally or alternatively perform digital misalignment compensation by adjusting a subset of pixels in one or both of the spatial light modulators in the display module used to generate image light.

[0008] The control circuitry can perform optical misalignment compensation based on optical misalignment detected by an optical misalignment sensor. The optical misalignment sensor may include at least one image sensor in a housing portion coupling a first waveguide to a second waveguide. The image sensor receives portion of image light from a first display module and a second display module via the first and second waveguides. The image sensor can generate image sensor data based on the received image light. The control circuitry can identify optical misalignment based on the image sensor data. In another suitable arrangement, an infrared emitter can emit infrared light onto a retroreflection grating array on or adjacent to the waveguide. The retroreflection grating can reflect the infrared light toward the user's face. The optical sensor array on or adjacent to the waveguide can generate a voltage in response to the infrared light reflected from the user's face. The control circuitry can estimate the optical misalignment based on the voltage. Attached Figure Description

[0009] Figure 1 These are illustrations of exemplary systems with displays based on some implementation schemes.

[0010] Figure 2 This is a top view of an exemplary optical system for a display with a display module that provides image light to a waveguide, according to some embodiments.

[0011] Figure 3 This is an illustration showing how an image generated by a first display module and a second display module can become misaligned according to some embodiments.

[0012] Figure 4 This is a cross-sectional side view of an exemplary display module that can compensate for optical misalignment with another display module according to some implementation schemes.

[0013] Figure 5 It is based on some implementation plans. Figure 4The front view of the example display module of the type shown.

[0014] Figure 6 This is an illustration showing how a first and second display modules, according to some embodiments, can generate image data in different parts of the field of view to compensate for optical misalignment.

[0015] Figure 7 This is a flowchart illustrating the exemplary operations involved in compensating for optical misalignment according to some implementation schemes.

[0016] Figure 8 This is a cross-sectional top view of an exemplary optical misalignment detection module with two image sensors according to some implementation schemes.

[0017] Figure 9 This is a cross-sectional top view of an exemplary optical misalignment detection module with an image sensor according to some implementation schemes.

[0018] Figure 10 This is an illustration showing how compensating for optical misalignment according to some embodiments can produce aligned images.

[0019] Figure 11 It is a top view of an exemplary display having a light emitter, a light sensor, and a retroreflection grating for detecting optical misalignment, according to some embodiments. Detailed Implementation

[0020] Figure 1 An exemplary system is illustrated, having a device with one or more near-eye display systems. System 10 may be a head-mounted device having one or more displays, such as a near-eye display 14 mounted within a support structure (housing) 20. The support structure 20 may have the shape of a pair of glasses (e.g., a support frame having left and right temple portions, left and right lens portions coupled between the temple portions, a bridge portion coupled between the left and right lens portions, etc.), may be formed with a helmet-shaped housing, or may have other configurations to facilitate mounting and securing components of the near-eye display 14 to the user's head or near their eyes. The near-eye display 14 may include one or more display modules such as display module 14A, and one or more optical systems such as optical system 14B. Display module 14A may be mounted in the support structure such as support structure 20. Each display module 14A may emit light 22, which is redirected towards the user's eye at an eye-adaptive zone 24 using an associated one of the optical systems 14B. Light 22 may be referred to herein as image light 22 (e.g., light containing and / or representing visible things such as scenes or objects).

[0021] The control circuit 16 can be used to control the operation of the system 10. The control circuit 16 may include storage and processing circuitry for controlling the operation of the system 10. The circuit 16 may include storage devices such as hard disk 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 the control circuit 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 (ASICs), and other integrated circuits. Software code (instructions) may be stored on the memory in the circuit 16 and run on the processing circuitry in the circuit 16 to implement operations for the system 10 (e.g., data acquisition operations, operations involving the use of control signals to adjust components, image rendering operations to generate image content for display to a user, etc.).

[0022] System 10 may include input / output circuitry such as input-output device 12. Input-output device 12 may be used to allow system 10 to receive data from external devices (e.g., tethered computers, portable devices such as handheld devices or laptops) or other electrical devices, and to allow user input to head-mounted device 10. Input-output device 12 may also be used to collect information about the environment in which system 10 (e.g., head-mounted device 10) operates. Output components in device 12 may allow system 10 to provide output to the user and may be used to communicate with external electronic devices. Input-output device 12 may include sensors and other components 18 (e.g., image sensors for acquiring images of real-world objects digitally merged with virtual objects on a display in system 10, accelerometers, depth sensors, light sensors, haptic output devices, speakers, batteries, wireless communication circuitry for communication between system 10 and external electronic devices, etc.). If desired, component 18 may include a gaze tracking sensor that collects gaze image data from the user's eyes at eye-fitting zone 24 to track the direction of the user's gaze in real time.

[0023] Display module 14A (sometimes referred to herein as display engine 14A, light engine 14A, or projector 14A) may include a reflective display (e.g., a display having a light source that generates illumination light (which is reflected from a reflective display panel to produce image light), such as a liquid crystal on silicon (LCOS) display, a ferroelectric liquid crystal on silicon (fLCOS) display, a digital micromirror device (DMD) display, or other spatial light modulator), an emissive display (e.g., a micro light-emitting diode (uLED) display, an organic light-emitting diode (OLED) display, a laser-based display, etc.), or other types of displays. The light source in display module 14A may include uLEDs, OLEDs, LEDs, lasers, combinations of these devices, or any other desired light-emitting component.

[0024] Optical system 14B can form lenses that allow an observer (see, for example, the observer's eye at eye zone 24) to view an image on display 14. Two optical systems 14B may be present, associated with the user's respective left and right eyes (e.g., for forming left and right lenses). At least two display modules 14A may be present (e.g., within the respective left and right temple portions of housing 20 or elsewhere), which are used to generate image light supplied to each respective optical system 14B. A single display 14 can generate images for both eyes, or a pair of displays 14 can 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 components in optical system 14B can be selected such that any gaps between the displays will be invisible to the user (e.g., allowing the images of the left and right displays to seamlessly overlap or merge).

[0025] If desired, the optical system 14B may include components (e.g., an optical combiner, etc.) to allow optical combination of real-world image light from a real-world image or object 25 with virtual (computer-generated) images, such as virtual images in image light 22. In this type of system (sometimes called an augmented reality system), the user of system 10 can 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., an arrangement where a camera captures a real-world image of object 25 and digitally merges that content with virtual content at optical system 14B).

[0026] If necessary, system 10 may include wireless circuitry and / or other circuitry to support communication with a computer or other external device (e.g., a computer that provides image content to display 14). During operation, control circuitry 16 may provide image content to display 14. This 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 14 by control circuitry 16 may be viewed by an observer at eye level 24.

[0027] Figure 2 It is possible Figure 1 A top view of the exemplary display 14 used in system 10. (See figure) Figure 2 As shown, the near-eye display 14 may include one or more display modules such as display module 14A, and an optical system such as optical system 14B. Optical system 14B may include optical elements such as one or more waveguides 26. Waveguide 26 may include one or more laminated substrates (e.g., laminated planes and / or curved layers, sometimes referred to herein as "waveguide substrates") formed of optically transparent materials such as plastics, polymers, glass, etc.

[0028] If desired, waveguide 26 may also include one or more layers of 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") are recorded. The holographic record may be stored as an optical interference pattern (e.g., alternating regions of different refractive indices) within a photosensitive optical material such as the holographic medium. This optical interference pattern can generate a holographic phase grating, which, when illuminated with a given light source, diffracts light to produce a three-dimensional reconstruction of the holographic record. The holographic phase grating may be a non-switchable diffraction grating encoded with a permanent interference pattern, or it may be a switchable diffraction grating where the emitted light can be modulated by controlling an electric field applied to the holographic recording medium. If desired, multiple holographic phase gratings (holograms) may be recorded within a holographic medium of the same volume (e.g., superimposed within a grating medium of the same volume). The holographic phase grating may be, for example, a volumetric hologram or a thin-film hologram in a grating medium. The grating medium may include photopolymers, gelatin such as dichromate gelatin, silver halide, holographic polymer dispersed liquid crystals, or other suitable holographic media.

[0029] The diffraction grating on waveguide 26 may include holographic phase gratings such as volumetric holograms or thin-film holograms, meta-gratings, or any other desired diffraction grating structure. The diffraction grating on waveguide 26 may also include surface-bump gratings formed on one or more surfaces of a substrate in waveguide 26, gratings formed by patterns of metallic structures, etc. The diffraction grating may, for example, include multiple multiplexed gratings (e.g., holograms) that at least partially overlap within a grating medium of the same volume (e.g., for diffracting light of different colors and / or light from different input angle ranges at one or more corresponding output angles).

[0030] Display engine 14A may include collimating optics 34. Collimating optics 34 may be referred to herein as eyepiece 34, eyepiece lens element 34, collimating lens 34, optics 34, or lens 34. Collimating optics 34 may include one or more lens elements that help direct image light 22 toward waveguide 26. Collimating optics 34 may be omitted if desired. If desired, additional collimating optics may be optically interposed between display module 14A and waveguide 14B (e.g., to help direct image light 22 toward the waveguide).

[0031] like Figure 2 As shown, display module 14A can generate image light 22 associated with image content to be displayed in eye-friendly area 24 (where it is displayed). Figure 2 In the example, display module 14A includes collimating optics 34 and a light source 44. The light source 44 may generate image light 22 (e.g., in a scenario where display module 14A is an emissive display module, the light source 44 may include an array of light emitters such as LEDs), or the light source 44 may generate illumination light provided to a spatial light modulator in display module 14A. The spatial light modulator may modulate the illumination light using image data to generate image light 22 (e.g., image light including an image such as that identified from the image data). The spatial light modulator may be a transmissive spatial light modulator (e.g., may include a transmissive display panel such as a transmissive LCD panel) or a reflective spatial light modulator (e.g., may include a reflective display panel such as a DMD display panel, an LCOS display panel, an fLCOS display panel, etc.).

[0032] Collimating optics 34 can be used to collimate the image light 22. Optical system 14B can be used to present the image light 22 output from display module 14A to the eye-friendly area 24. Optical system 14B may include one or more optical couplers such as input coupler 28, cross coupler 32, and output coupler 30. Figure 2In the example, input coupler 28, cross coupler 32, and output coupler 30 are formed at or on waveguide 26. Input coupler 28, cross coupler 32, and / or output coupler 30 may be completely embedded in the substrate of waveguide 26, partially embedded in the substrate of waveguide 26, or mounted to waveguide 26 (e.g., mounted to the outer surface of waveguide 26), etc.

[0033] Figure 2 The examples provided are merely illustrative. One or more of these couplers (e.g., cross coupler 32) may be omitted. Optical system 14B may include multiple waveguides stacked laterally and / or vertically relative to each other. Each waveguide may include one, two, all, or none of the couplers from couplers 28, 32, and 30. Waveguide 26 may be at least partially bent or folded if desired.

[0034] Waveguide 26 can guide image light 22 downward along its length via total internal reflection. Input coupler 28 can be configured to couple image light 22 from display module 14A into waveguide 26, while output coupler 30 can be configured to couple image light 22 from inside waveguide 26 to outside waveguide 26 and toward eye-viewing area 24. If desired, input coupler 28 may include an input coupling prism. As an example, display module 14A can emit image light 22 toward optical system 14B in the +Y direction. When image light 22 strikes input coupler 28, input coupler 28 can redirect image light 22 such that the light propagates within waveguide 26 via total internal reflection toward output coupler 30 (e.g., in the +X direction). When image light 22 strikes output coupler 30, output coupler 30 can redirect image light 22 away from waveguide 26 toward peephole 24 (e.g., rearward along the Y-axis). For example, in a scenario where the cross coupler 32 is formed at the waveguide 26, the cross coupler 32 can redirect the image light 22 to one or more directions as it propagates downward along the length of the waveguide 26.

[0035] Input coupler 28, cross coupler 32, and output coupler 30 may be based on reflective and refractive optics, or on holographic (e.g., diffractive) optics. In an arrangement where couplers 28, 30, and 32 are formed from reflective and refractive optics, couplers 28, 30, and 32 may include one or more reflectors (e.g., micromirrors, partial mirrors, louvered mirrors, or arrays of other reflectors). In an arrangement where couplers 28, 30, and 32 are based on holographic optics, couplers 28, 30, and 32 may include diffraction gratings (e.g., volume holograms, surface gratings, etc.). Couplers 28, 30, and 32 may be formed using any desired combination of holographic and reflective optics.

[0036] In a suitable arrangement sometimes described herein as an example, the output coupler 30 is formed of a diffraction grating or micromirrors (e.g., a volumetric hologram recorded on a grating medium stacked between transparent polymer waveguide substrates, an array of micromirrors embedded in polymer layers interposed between transparent polymer waveguide substrates, etc.) embedded within waveguide 26, while the input coupler 28 comprises a prism mounted to one or more layers of a diffraction grating structure on the outer surface of waveguide 26 (e.g., the outer surface defined by a waveguide substrate that contacts the grating medium or polymer layer used to form the output coupler 30) or diffraction grating structure. This example is merely illustrative.

[0037] exist Figure 2 In the example, for clarity, only a single optical system 14B and a single display module 14A are shown. In practice, system 10 may include a first display module 14A that provides image light 22 to the first optical system 14B for display at a first eye-fitting zone 24 (e.g., an eye-fitting zone aligned with the user's left eye), and may include a second display module 14A that provides image light 22 to the second optical system 14B for display at a second eye-fitting zone 24 (e.g., an eye-fitting zone aligned with the user's right eye). For clarity, the operation of a single (e.g., first) display module 14A and a single (e.g., first) optical system 14B is described herein as an example.

[0038] For example, the first display module 14A and the first optical system 14B may provide first image data (e.g., an image frame stream for display at the user's left eye) to a first eye-friendly region. Simultaneously, the second display module 14A and the second optical system 14B provide second image data (e.g., an image frame stream for display at the user's right eye and corresponding to the image frame stream provided to the user's left eye by the first display module 14A and the first optical system 14B). To ensure proper binocular vision of the displayed image, the first display module 14A and the first optical system 14A need to be properly aligned relative to the second display module 14B and the second optical system 14B. For example, this optical alignment may be performed during the manufacturing, assembly, calibration, or testing of system 10 (e.g., in a manufacturing or assembly system). For example, such factory alignment may compensate for optical misalignment associated with manufacturing tolerances of system 10. Furthermore, when system 10 is used by the end user, the display modules and optical systems may become misaligned relative to each other over time (e.g., due to shock events, manufacturing tolerances, thermal effects, wear, etc.).

[0039] If the optical misalignment is not corrected, the user may perceive an undesirable misalignment in the image provided to each eye zone (e.g., the user may not perceive a display image with satisfactory binocular vision). Figure 3 This is an illustration showing that optical misalignment can be perceived by the user of system 3. (See diagram below.) Figure 3 As shown, image 46 can be provided to a first eye-adaptive area 24 (e.g., a left eye-adaptive area aligned with the user's left eye) by a first (left) display module 14A and a first (left) optical system 14B. Correspondingly, image 50 can be provided to a second eye-adaptive area 24 (e.g., a right eye-adaptive area aligned with the user's right eye) by a second (right) display module 14A and a second (right) optical system 14B. When the first display module 14A and the first optical system 14B are properly aligned with the second display module 14A and the second optical system 14B, the objects in images 46 and 50 can be properly displayed and viewed by the user. However, when the first display module 14A and the first optical system 14B are optically misaligned with the second display module 14A and the second optical system 14B, the objects in images 46 and 50 may be misaligned (e.g., by offset 48) and may therefore appear unclear or confusing to the user.

[0040] System 10 can perform optical alignment operations to ensure proper optical alignment between the left and right eye-correcting zones. The optical alignment operations can be performed during the assembly / manufacturing of system 10 and / or while system 10 is being used by the end user. In a suitable arrangement described herein by way of example, each of the display modules 14A may include a mechanical alignment structure that can be adjusted to ensure that the display modules are optically aligned.

[0041] Figure 4 This is a cross-sectional side view of a given display module 14A with a mechanical alignment structure. Figure 4 The display module 14A can be used to form one or both of the display modules that provide image light to the left and right eye-adaptive zones of the system 10. For example... Figure 4 As shown, display module 14A may include display module housing 52 (sometimes referred to herein as display module chassis 52). Figure 4 In this example, display module 14A includes a spatial light modulator 58 and an illumination optics 56. This is merely illustrative, and in another suitable arrangement, display module 14A may be an emissive display module.

[0042] Illumination optics 56 and spatial light modulator 58 can be mounted within the display module housing 52. Illumination optics 56 provides illumination light 64 to spatial light modulator 58. Spatial light modulator 58 modulates an image onto illumination light 64 to generate image light 22. Image light 22 can be guided towards input coupler 28 of waveguide 26 by collimating optics 34. Figure 2 The collimating optics 34 can be mounted to the display module housing 52 (e.g., at the opening end of the display module housing 52).

[0043] The illumination optics 56 may include light sources 44. Light sources 44 may include LEDs, OLEDs, uLEDs, lasers, etc. For example, as indicated by arrow 66, the illumination optics 56 may include a first light source 44A emitting illumination light of a first color (e.g., red illumination light), a second light source 44B emitting illumination light of a second color (e.g., green illumination light), and a third light source 44C emitting illumination light of a third color (e.g., blue illumination light). This example is merely illustrative. Typically, each light source 44 may emit light of any desired color. If desired, light source 44A may be replaced by an array of light sources, light source 44B may be replaced by an array of light sources, and / or light source 44C may be replaced by an array of light sources. If desired, the illumination optics 56 may include more than three or fewer light sources 44.

[0044] Each light source 44 in the illumination optics 56 can emit a corresponding portion of the illumination light 64, as indicated by arrow 66. The illumination optics 56 may include partially reflective structures such as an X-plate 54, which combine the light emitted by each light source 44 in the illumination optics 56 into the illumination light 64 (e.g., the illumination light 64 may include red, green, and blue light emitted by light sources 44A, 44B, and 44C). For example, the X-plate 54 may include a pair of partially reflective plates that reflect some wavelengths of light while simultaneously transmitting other wavelengths. If desired, the X-plate 54 may be provided with light wedges to help support the X-plate 54 (for clarity, in...). Figure 4 (Not shown in the image). For example, the X-plate 54 may be formed by a coating or layer on the surface of the optical wedge. In a scenario where an optical wedge is provided in an illumination optics 56 to support the X-plate 54, the X-plate and the optical wedge may sometimes be collectively referred to as a prism (e.g., prism 54).

[0045] Illumination light 64 may include illumination light generated by light source 44A (e.g., red light), illumination light generated by light source 44B (e.g., green light), and / or illumination light generated by light source 44C (e.g., blue light). X-plate 54 may provide illumination light 64 to spatial light modulator 58. Lens elements may be used if desired (for clarity, ...). Figure 3 (Not shown in the image) to help guide the illumination light 64 from the illumination optics 56 to the spatial light modulator 58.

[0046] Spatial light modulator 58 may include prism 80 and reflective display panel such as display panel 68. Display panel 68 may be a DMD panel, LCOS panel, fLCOS panel, or other reflective display panel. If desired, display panel 68 may be mounted to display module housing 52. Prism 80 may direct illumination light 64 onto display panel 68 (e.g., different pixels on display panel 68). Control circuit 16 ( Figure 1The display panel 68 can be controlled to selectively reflect illumination light 64 at each pixel location to generate image light 22 (e.g., image light having an image as modulated onto the illumination light by the display panel 68). Prism 80 can guide the image light 22 toward collimating optics 34. Collimating optics 34 can guide the image light 22 out of display module 14A and toward input coupler 28. Figure 2 ).

[0047] The position and / or orientation of display module 14A can be mechanically adjusted to ensure that the display module is optically aligned with other display modules 14A in system 10 (e.g., to mitigate optical misalignment between display modules and optical systems providing image light to the left and right eye zones). If necessary, a mechanical alignment structure (such as mechanical alignment structure 72) can be used to mechanically adjust the orientation of the display module 14A itself. Mechanical alignment structure 72 can be electrically and / or mechanically actuated. Mechanical alignment structure 72 can be coupled to display module housing 52. Mechanical alignment structure 72 can rotate the entire display module housing 52 and thus rotate display module 14A.

[0048] For example, the mechanical alignment structure 72 can cause the display module housing 52 to rotate about one or more axes (such as axis 74). This rotation can cause the optical axis 62 of the collimating optics 34 to rotate about axis 74. For example, in a first configuration, the mechanical alignment structure 72 can orient the display module 14A such that the optical axis 62 points in the direction of arrow 78. In a second configuration, the mechanical alignment structure 72 can orient the display module 14A such that the optical axis 62 points in the direction of arrow 78. This example is merely illustrative. If desired, the mechanical alignment structure 72 can cause the display module housing 52 to rotate about more than one axis and / or can perform mechanical translation of the display module housing 52 (e.g., parallel to...). Figure 4 (The X, Y, and / or Z axes). This rotation helps ensure that the display module 14A is properly aligned to provide the user with satisfactory binocular vision.

[0049] If necessary, a mechanical alignment structure (such as mechanical alignment structure 84) can mechanically adjust the position and / or orientation of the collimating optics 34 relative to the rest of the display module 14A (e.g., without adjusting the position or orientation of the display module housing 52 or other components housed within the display module housing 52). Mechanical alignment structure 84 may include, for example, a piezoelectrically driven flexure stage. Therefore, mechanical alignment structure 84 may sometimes be referred to herein as flexure stage 84. The collimating optics 34 may be mounted within the eyepiece housing 60 (sometimes referred to herein as eyepiece barrel 60 or lens housing 60). Flexure stage 84 may be mounted to the display module housing 52 using adhesive 82.

[0050] The flexure stage 84 can couple the eyepiece housing 60 to the display module housing 52. The flexure stage 84 can receive control signals (e.g., from...). Figure 1 The control circuit 16) causes the flexure stage 84 to adjust the mechanical position of the eyepiece housing 60 and thus the collimating optics 34 relative to the display module housing 52. For example, the flexure stage 84 can be used to adjust the mechanical position of the eyepiece housing 60 and thus the collimating optics 34 relative to the display module housing 52. Figure 4 The eyepiece housing 60 is translated relative to the spatial light modulator 58 in the X, Y, and / or Z axes. This mechanical translation helps ensure that the display module 14A is properly aligned to provide the user with satisfactory binocular vision.

[0051] If necessary, the position and / or orientation of the display panel 68 can be adjusted relative to the display module housing 52. For example, a mechanical alignment structure (such as mechanical alignment structure 70) can mechanically adjust the position and / or orientation of the display panel 68 relative to the rest of the display module 14A. This mechanical translation helps ensure that the display module 14A is properly aligned to provide a satisfactory binocular vision to the user.

[0052] Figure 4 The examples are merely illustrative. One, two, or all three of mechanical alignment structures 84, 70, and 72 may be used to perform optical alignment operations for display module 14A (e.g., mechanical alignment structures 84, 70, and / or 72 may be omitted). In scenarios where the deflection stage 84 is omitted, adhesive 82 may be used to mount the eyepiece housing 60 to the display module housing 54. If desired, display module 14A may additionally or alternatively perform digital alignment operations (e.g., alignment operations in which image data is provided to a subset of areas of the display panel to compensate for optical misalignment with other display modules in system 10). Mechanical alignment structures 72, 84, and 70 may be mechanically adjustable, electrically adjustable, electromechanical adjustable, etc. (e.g., mechanical alignment structures 72, 84, and 70 may include microelectromechanical system (MEMS) structures, piezoelectric structures, actuators, or any other desired structures for adjusting some or all of the mechanical positions in display module 14A).

[0053] Figure 5 This is a front view showing how the flexure stage 84 can mechanically translate the position of the eyepiece housing 60 relative to the rest of the display module 14A (e.g., as along...). Figure 4 (The direction of arrow 86 is cut off). For example... Figure 5As shown, display module 14A may include a first pair of flexure stages 84H coupled to opposing first and second sides of eyepiece housing 60. Display module 14A may additionally or alternatively include a second pair of flexure stages 84V coupled to opposing third and fourth sides of eyepiece housing 60. Flexure stages 84H can translate the position of eyepiece housing 60 relative to the remainder of display module 14A in a first direction, as indicated by arrow 88. Flexure stages 84V can translate the position of eyepiece housing 60 relative to the remainder of display module 14B in a second direction, as indicated by arrow 90. Flexure stages 84H and 84V can therefore be used in combination to perform any desired two-dimensional translation of eyepiece housing 60, thereby ensuring proper optical alignment with other display modules. Flexure stages 84H or 84V may be omitted if desired. Other mechanical and / or electromechanical structures may be used to adjust the position and / or orientation of eyepiece housing 60 if desired.

[0054] Figure 6 This is a diagram illustrating how the display module 14A can perform digital alignment operations. (See diagram for example.) Figure 6 As shown, control circuit 16 can control the first display module 14A to generate image data 92 only within a first region corresponding to the field of view 91 (e.g., for display at the left eye area). Control circuit 16 can control the second display module 14A to generate image data 94 only within a second region corresponding to the field of view 93 (e.g., for display at the right eye area). The position of image data 92 may differ from the position of image data 94, such that the difference in position compensates for the effect of optical misalignment between the left and right eye areas. The positions of image data 92 and / or 94 may change over time to compensate for any changes in misalignment that may occur.

[0055] Control circuitry 16 can control image data 92 and the position of image data 94 by providing image data only to a subset of pixels in display panel 68 and / or by providing illumination light 64 only to that subset of pixels in display panel 68. As optical misalignment changes over time, the subset of pixels in display panel 68 can change such that the image light generated by the reflective display panel compensates for any change in optical misalignment. Performing digital alignment in this manner can result in a smaller image across the entire eye-sensing area (e.g., because only a subset of the field of view of the reflective display panel is used at a given time to allow the space of that subset to change over time). However, improvements in perceptual alignment between the left and right eye-sensing areas can compensate for any such reduction in the size of the displayed image.

[0056] Display module 14A can perform only digital alignment (e.g., as...) Figure 6 (as shown) or may be used in addition to Figure 4In addition to mechanical alignment, digital alignment is performed using one or more of the mechanical alignment structures 84, 70, and 72. The combination of one or more of these alignment techniques helps ensure proper optical alignment between the left and right adaptation zones over time.

[0057] Figure 7 This is a flowchart illustrating exemplary operations that can be performed by system 10 to compensate for optical misalignment between the left and right adaptive eye zones. These operations may be performed during the assembly / manufacturing of system 10 and / or during end-user use of system 10.

[0058] At operation 96, system 10 can detect optical misalignment between the left and right eye zones. If needed, system 10 can detect both the presence and quantity / direction of the optical misalignment. For example, system 10 may include one or more optical misalignment sensors (sometimes referred to herein as optical alignment sensors). Optical misalignment sensors can monitor any optical misalignment between the left and right eye zones. If needed, optical misalignment sensors can detect the amount and / or direction of the misalignment. This is performed during the assembly / manufacturing of system 10. Figure 7 In the scenario of operation, if necessary, an external optical misalignment sensor that is not part of system 10 can be used to detect optical misalignment.

[0059] At operation 98, system 10 may compensate for optical misalignment detected between the left and right eye zones (e.g., based on optical misalignment detected during operation 96). For example, system 10 may use mechanical alignment structure 72 to rotate the entire display module housing 52 and display module 14A (at operation 100). System 10 may additionally or alternatively use flexure stage 84 to translate the position of eyepiece housing 60 (at operation 102). System 10 may additionally or alternatively use mechanical alignment structure 70 to translate and / or rotate the position of display panel 68 (at operation 104). Figure 6 As shown, system 10 can additionally or alternatively perform digital misalignment correction by changing the portion of the field of view where image data is provided between the left and right adaptive eye areas. Figure 7 Operation 106 times).

[0060] System 10 can perform one, more, or all of operations 100, 102, 104, and 106 to compensate for optical misalignment detected during processing operation 96. One or more of operations 100, 102, 104, and 106 may be omitted. For example, the direction and / or magnitude of each adjustment performed at steps 100, 102, 104, and 106 may be determined based on the direction and / or magnitude of the optical misalignment detected during processing operation 96. This is performed when system 10 is used by an end user. Figure 7In the scenario described in the steps, the processing can loop back to operation 96, as shown in path 108, to allow updates to the digital and / or mechanical alignment based on feedback from the optical misalignment detection. The system 10 can thus continuously or periodically monitor any changes in optical alignment / misalignment between the left and right eye zones of the system 10, so that one or both of the corresponding display modules 14A can be adjusted to mitigate changes in alignment / misalignment over time.

[0061] If necessary, system 10 may include methods for detecting optical misalignment between the left and right adaptive eye zones (e.g., in...). Figure 7 During the processing of operation 96, an optical misalignment sensor is used. In a suitable arrangement described herein as an example, the optical misalignment sensor can be integrated into the optical misalignment detection module. Figure 8 This is a cross-sectional top view showing how an optical misalignment detection module can be used to detect misalignment between the left and right adaptive eye zones.

[0062] like Figure 8 As shown, system 10 may include an optical misalignment detection module 112. The optical misalignment detection module 112 may be integrated within housing portion 110. Housing portion 110 may, for example, be formed into... Figure 1 The housing portion 110 is part of the housing 20. In a suitable arrangement described herein by way of example, the housing portion 110 may be the nose section of the housing 20. The system 10 may include a first waveguide 26 (such as waveguide 26A) and may include a second waveguide 26 (such as waveguide 26B). The housing portion 110 may couple waveguide 26A to waveguide 26B.

[0063] Waveguide 26B can receive image light 22B (e.g., containing) from the first display module 14A. Figure 3 Image light from image 46). Waveguide 26A can receive image light 22A from the second display module 14A (e.g., containing image light 46). Figure 3 The image light 22B is the image light from image 50. Waveguide 26B may have an output coupler 30B that couples a first portion of the image light 22B out of waveguide 26B and toward a first eye region 24B (e.g., the left eye region). Output coupler 30B allows a second portion of the image light 22B to pass through without coupling or diffracting the second portion of the image light 22B out of waveguide 26B. Waveguide 26B may include an additional output coupler 116B (e.g., a set of diffraction gratings, a louvered mirror, an output coupling prism, etc.). Output coupler 116B couples a second portion of the image light 22B out of waveguide 26B and into housing portion 110.

[0064] Similarly, waveguide 26A may have an output coupler 30A that couples a first portion of image light 22A out of waveguide 26A toward a first eye region 24A (e.g., the right eye region). Output coupler 30A allows a second portion of image light 22A to pass through without coupling or diffracting the second portion of image light 22A out of waveguide 26A. Waveguide 26A may include an additional output coupler 116A (e.g., a set of diffraction gratings, a louvered mirror, an output coupling prism, etc.). Output coupler 116A couples a second portion of image light 22A out of waveguide 26A and into housing portion 110.

[0065] The optical misalignment detection module 112 may have a first image sensor 114A and a second image sensor 114B (e.g., a CMOS image sensor, a four-element image sensor, other types of image sensors, etc.). The housing portion 110 may include a lens element 118A that guides image light 22A from the output coupler 116A toward the image sensor 114A. The housing portion 110 may also include a lens element 118B that guides image light 22B from the output coupler 116B toward the image sensor 114B. Image sensors 114A and 114B can collect image sensor data from image light 22A and 22B, and can process the image sensor data to detect any optical misalignment between eye-friendly areas 24A and 24B (e.g., control circuitry 16 can use image light 22A and 22B to detect misalignment with...). Figure 3 Arrow 48 is associated with optical misalignment. This image data can be used to determine when and how to adjust one or both of the display modules 14A to compensate for the misalignment (e.g., during processing). Figure 7 (While operating 98). As an example, specific pixels in display panel 68 can be illuminated. The resulting images on image sensors 114A and 114B can then be used to calculate the relative misalignment between the left and right adaptive eye areas. Relative timing measurements can be performed via multiple pixels.

[0066] exist Figure 8 In this example, housing portion 110 includes two image sensors for detecting optical misalignment between eye-viewing areas 24A and 24B. This is merely illustrative. In another suitable arrangement, housing portion 110 may include a single image sensor for detecting optical misalignment between eye-viewing areas 24A and 24B. Figure 9 The image shows a cross-sectional top view of housing portion 110 in a suitable example, wherein housing portion 110 includes a single image sensor for detecting optical misalignment.

[0067] like Figure 9As shown, the housing portion 110 may include a first mirror 120, a second mirror 122, a third mirror 124, a partial reflection beam splitter 126, a lens element 128, and a single image sensor 114. Mirror 120 may receive signals from output coupler 116A. Figure 8 Image light 22A can be reflected towards mirror 122. Mirror 122 can reflect image light 22A towards partial reflection beam splitter 126. Simultaneously, mirror 124 can receive image light from output coupler 116B. Figure 8 Image light 22B is reflected towards partial reflection beam splitter 126. Partial reflection beam splitter 126 can combine image light 22B and image light 22A and can provide image light to image sensor 114 via lens element 128. Image sensor 114 can collect image sensor data from image light and can process image sensor data to detect any optical misalignment between eye-friendly areas 24A and 24B.

[0068] Figure 10 This is a diagram illustrating how system 10 can compensate for optical misalignment between the left and right adaptive eye zones. (See diagram for example.) Figure 10 As shown, when optical misalignment exists, image data 132 provided to one of the eye-fitting areas (e.g., eye-fitting area 24A) will be misaligned relative to image data 134 provided to the other eye-fitting area (e.g., eye-fitting area 24B). System 10 can detect the presence, magnitude, and / or direction of this misalignment (e.g., during processing). Figure 7 (While operating 96). By mechanically adjusting some or all of one or both of the display modules 14A (e.g., during processing). Figure 7 (while performing operations 100, 102, and 104) and / or perform digital alignment operations (e.g., during processing) Figure 7 (while performing operation 106), such as Figure 10 As indicated by arrow 136, control circuitry 16 ensures proper alignment of image data 132 with image data 134. This allows the user to perceive image data across both eye-friendly zones with satisfactory binocular vision.

[0069] If needed, system 10 may include an optical emitter, an optical sensor, and a retroreflection grating for detecting optical misalignment. Figure 11 This is an illustration showing how system 10 can include an optical emitter, an optical sensor, and a retroreflection grating for detecting optical misalignment. (See diagram for reference.) Figure 11 As shown, system 10 may include a first housing portion 20A, which includes a first waveguide for providing light to a first eye-friendly region (e.g., housing portion 20A may include a waveguide for providing light to a first eye-friendly region). Figure 8 The eye-friendly area 24B provides a waveguide 26B for light. The system 10 may also include a second housing portion 20B (e.g., the left temple portion of the housing).

[0070] A light emitter 140 may be mounted within the second housing portion 20B. The light emitter 140 may emit light 142 (e.g., light other than image light to be provided to the eye-friendly area). As an example, light 142 may be emitted at infrared or near-infrared wavelengths. The housing portion 20A may include one or more retroreflection gratings, such as retroreflection grating 144. Retroreflection grating 144 may be placed at different locations across the housing portion 20A and may be used to form... Figure 2 The grating separation of couplers 28, 30, or 32. Retroreflection grating 144 may include a surface-roughened grating, a thin-film hologram, a volume hologram, a meta-grating, or any other desired diffraction grating structure. If desired, retroreflection grating 144 may be replaced with a mirror or other reflective structure.

[0071] A retroreflective grating 144 may reflect light 142 toward a user's face (e.g., face 148). Light 142 may be reflected from face 148 as reflected light 142'. Housing portion 20A may include one or more optical sensors 146. As an example, optical sensor 146 may include a light reflection sensor (e.g., a single-pixel sensor that generates a voltage corresponding to the number of photons received). Optical sensor 146 may be positioned at different locations across housing portion 20A. Optical sensor may receive reflected light 142' and may collect optical sensor data (e.g., voltage values) from reflected light 142'. Control circuitry 16 may process the optical sensor data to estimate the distance between housing portion 20A and face 148. Changes in this estimated distance over time may indicate what can be done in processing. Figure 7 Step 98 simultaneously compensates for optical misalignment or changes in optical misalignment. Figure 11 The example provided is merely illustrative. More than two retroreflective gratings 144 and / or more than two optical sensors 146 may be present in the housing portion 20A. If desired, the retroreflective gratings 144 can also be used to perform gaze tracking operations. Although Figure 11 Only one side of system 10 is shown (e.g., the left side of the user's face), but a similar structure could also be provided on the other side of system 10 (e.g., the right side of the user's face). Data captured by optical sensors for each side can be compared to detect misalignment between the left and right adaptive eye areas.

[0072] According to one embodiment, a display system is provided, the display system comprising: a waveguide; an input coupler on the waveguide and configured to couple image light into the waveguide; an output coupler on the waveguide and configured to couple the image light out of the waveguide; and a display module configured to generate the image light, the display module comprising: a display module housing; at least one light source within the display module housing; a collimating optics mounted to the display module housing and having an optical axis, the collimating optics being configured to guide the image light toward the input coupler; and an alignment structure configured to adjust the position of the optical axis relative to the waveguide.

[0073] According to another embodiment, the alignment structure is configured to mechanically rotate the display module housing about an axis.

[0074] According to another embodiment, the display module includes: a lens housing in which the collimating optics is mounted; and a set of piezoelectrically driven flexure stages that couple the lens housing to the display module housing, the set of piezoelectrically driven flexure stages being configured to mechanically translate the lens housing relative to the display module housing along a first axis.

[0075] According to another embodiment, the display module includes a set of additional piezoelectrically driven flexure stages that couple the lens housing to the display module housing. The set of additional piezoelectrically driven flexure stages is configured to mechanically translate the lens housing relative to the display module housing along a second axis orthogonal to the first axis.

[0076] According to another embodiment, the display module includes a reflective display panel that is mounted to the display module housing and configured to generate the image light by modulating illumination light emitted by the at least one light source using image data.

[0077] According to another embodiment, the display module includes an additional alignment structure configured to adjust the position of the reflective display panel relative to the display module housing.

[0078] According to another embodiment, the display module includes a reflective display panel mounted to the display module housing and configured to generate image light by modulating illumination light emitted by the at least one light source using image data, and the alignment structure is configured to adjust the position of the reflective display panel relative to the display module housing.

[0079] According to another embodiment, the display module includes a lens housing, the collimating optics are mounted inside the lens housing, the alignment structure couples the lens housing to the display module housing, and the alignment structure is configured to mechanically translate the position of the lens housing relative to the display module housing along at least one axis.

[0080] According to another embodiment, the display module includes a display panel mounted within a display panel housing and having pixels, the display panel being configured to generate image light by using a subset of the pixels to modulate illumination light generated by the at least one light source with image data, and the display system including control circuitry configured to change the subset of pixels used by the display panel.

[0081] According to another embodiment, the display system includes: an additional waveguide; an additional input coupler on the additional waveguide and configured to couple additional image light into the additional waveguide; an additional output coupler on the additional waveguide and configured to couple the additional image light out of the additional waveguide; an additional display module configured to generate the additional image light; an optical alignment sensor configured to detect the position of the display module relative to the additional display module; and a control circuit configured to control the mechanical alignment structure to mechanically adjust the position of the optical axis relative to the waveguide based on the position detected by the optical alignment sensor.

[0082] According to another embodiment, the optical alignment sensor includes at least one image sensor configured to receive a portion of the image light from the waveguide and a portion of the additional image light from the additional waveguide.

[0083] According to another embodiment, the output coupler is configured to transmit the portion of the image light to a first additional output coupler on the waveguide, the first additional output coupler being configured to couple the portion of the image light out of the waveguide toward the optical alignment sensor, the additional output coupler being configured to transmit the portion of the additional image light to a second additional output coupler on the additional waveguide, and the second additional output coupler being configured to couple the portion of the additional image light out of the waveguide toward the optical alignment sensor.

[0084] According to another embodiment, the at least one image sensor includes a first image sensor and a second image sensor, the first image sensor being configured to receive the portion of the image light, and the second image sensor being configured to receive the portion of the additional image light.

[0085] According to another embodiment, the at least one image sensor includes a single image sensor, and the display system includes: a first mirror; a second mirror; a third mirror; and a partial reflection beamsplitter, the first mirror being configured to reflect the portion of the image light toward the second mirror, the second mirror being configured to reflect the portion of the image light toward the partial reflection beamsplitter, the third mirror being configured to reflect the additional portion of the image light toward the partial reflection beamsplitter, and the partial reflection beamsplitter being configured to guide the portion of the image light and the additional portion of the image light toward the single image sensor.

[0086] According to another embodiment, the optical alignment sensor includes: a first light emitter configured to emit first infrared light; a first set of retroreflection gratings on the waveguide and configured to diffract the first infrared light; a second light emitter configured to emit second infrared light; a second set of retroreflection gratings on the additional waveguide and configured to diffract the second infrared light; a first set of light reflection sensors on the first waveguide and configured to generate a first set of voltages based on a reflected version of the first infrared light diffracted by the first set of retroreflection gratings; and a second set of light reflection sensors on the second waveguide and configured to generate a second set of voltages based on a reflected version of the second infrared light diffracted by the second set of retroreflection gratings. The control circuit is configured to control the mechanical alignment structure to mechanically adjust the position of the optical axis relative to the waveguide based on the first set of voltages and the second set of voltages.

[0087] According to one embodiment, a display system is provided, the display system comprising: a first display module configured to generate a first image light; a second display module configured to generate a second image light; a first waveguide having a first output coupler and a second output coupler, the first output coupler being configured to couple a first portion of the first image light out of the first waveguide; a second waveguide having a third output coupler and a fourth output coupler, the third output coupler being configured to couple the first portion of the second image light out of the second waveguide; a housing portion coupling the first waveguide to the second waveguide; and at least one image sensor. An image sensor is located in the housing portion; a second output coupler is configured to couple a second portion of the first image light out of the first waveguide and toward the at least one image sensor in the housing portion; a fourth output coupler is configured to couple a second portion of the second image light out of the second waveguide and toward the at least one image sensor in the housing portion; and the at least one image sensor is configured to generate image sensor data based on the second portion of the first image light and the second portion of the second image light; and a control circuit is configured to identify the position of the first image light relative to the second image light based on the image sensor data generated by the at least one image sensor.

[0088] According to another embodiment, the control circuit is configured to mechanically adjust the first display module to compensate for the identified optical misalignment.

[0089] According to another embodiment, the control circuit is configured to mechanically adjust the second display module to compensate for the identified optical misalignment.

[0090] According to another embodiment, the control circuit is configured to change a subset of the pixels used by the first display module to generate the first image light in order to compensate for the identified optical misalignment.

[0091] According to one embodiment, a display system is provided, the display system comprising: a housing having a first housing portion and a second housing portion; a display module located in the first housing portion and configured to generate image light, the display module having collimating optics configured to transmit the image light and the collimating optics having an optical axis; a waveguide located in the second housing portion and configured to guide the image light; an infrared light emitter located in the first housing portion and configured to emit infrared light; a set of retroreflection gratings located in the first housing portion and configured to reflect the infrared light; a set of optical sensors located in the first housing portion and configured to generate a voltage based on the reflected infrared light; and a control circuit configured to mechanically adjust the orientation of the optical axis based on the voltage generated by the set of optical sensors.

[0092] The foregoing description is merely illustrative and various modifications can be made to the described implementation scheme. The described implementation scheme can be implemented independently or in any combination.

Claims

1. A display system, comprising: First waveguide; A first input coupler is located on the first waveguide and configured to couple a first image light into the first waveguide; A first output coupler is located on the first waveguide and configured to couple a first portion of the first image light out of the first waveguide. A second output coupler is located on the first waveguide, wherein the first output coupler is configured to transmit a second portion of the first image light to the second output coupler; Second waveguide; A second input coupler is located on the second waveguide and configured to couple second image light into the second waveguide; A third output coupler is located on the second waveguide and configured to couple a third portion of the second image light out of the second waveguide; A fourth output coupler is located on the second waveguide, wherein the third output coupler is configured to transmit a fourth portion of the second image light to the fourth output coupler; An optical alignment sensor is located in a housing portion that couples the first waveguide to the second waveguide, wherein a second output coupler is configured to couple a second portion of the first image light out of the first waveguide and toward the optical alignment sensor, and wherein a fourth output coupler is configured to couple a fourth portion of the second image light out of the second waveguide and toward the optical alignment sensor. A first display module, configured to generate the first image light, the first display module comprising: Display module casing, At least one light source, said at least one light source being located within the display module housing. A collimating optics device, mounted to the display module housing and having an optical axis, is configured to guide the first image light toward the first input coupler. An alignment structure configured to adjust the position of the optical axis relative to the first waveguide; as well as A second display module is configured to generate the second image light.

2. The display system of claim 1, wherein the alignment structure is configured to mechanically rotate the display module housing about an axis.

3. The display system according to claim 2, wherein the first display module further comprises: A lens housing, wherein the collimating optical device is installed inside the lens housing; as well as A set of piezoelectrically driven flexure stages couples the lens housing to the display module housing, wherein the set of piezoelectrically driven flexure stages is configured to mechanically translate the lens housing relative to the display module housing along a first axis.

4. The display system according to claim 3, wherein the first display module further comprises: A set of additional piezoelectrically driven flexure stages couples the lens housing to the display module housing, wherein the set of additional piezoelectrically driven flexure stages is configured to mechanically translate the lens housing relative to the display module housing along a second axis orthogonal to the first axis.

5. The display system according to claim 3, wherein the first display module further comprises: A reflective display panel is mounted to the display module housing and configured to generate the first image light by modulating illumination light emitted by the at least one light source using image data.

6. The display system according to claim 5, wherein the first display module further comprises: An additional alignment structure is configured to adjust the position of the reflective display panel relative to the display module housing.

7. The display system according to claim 1, wherein the first display module further comprises: A reflective display panel is mounted to the display module housing and configured to generate the first image light by modulating illumination light emitted by the at least one light source using image data, wherein the alignment structure is configured to adjust the position of the reflective display panel relative to the display module housing.

8. The display system according to claim 1, wherein the first display module further comprises: A lens housing, wherein the collimating optics are mounted within the lens housing, the alignment structure couples the lens housing to the display module housing, and the alignment structure is configured to mechanically translate the position of the lens housing relative to the display module housing along at least one axis.

9. The display system according to claim 1, wherein the first display module further comprises: A display panel, mounted within a display panel housing and having pixels, wherein the display panel is configured to generate the first image light by using image data to modulate illumination light generated by the at least one light source using a subset of the pixels, and wherein the display system includes control circuitry configured to change a subset of the pixels used by the display panel.

10. The display system according to claim 1, The optical alignment sensor is configured to detect the position of the first display module relative to the second display module; and The display system further includes a control circuit configured to control the alignment structure to mechanically adjust the position of the optical axis relative to the first waveguide based on the position detected by the optical alignment sensor.

11. The display system of claim 10, wherein the optical alignment sensor comprises: At least one image sensor, the at least one image sensor being configured to receive a second portion of the first image light from the first waveguide and a fourth portion of the second image light from the second waveguide.

12. The display system according to claim 11, further comprising: The housing includes left and right temple portions, left and right lens portions coupled between the temple portions, and a bridge portion coupled between the left and right lens portions, wherein the optical alignment sensor is located within the bridge portion.

13. The display system of claim 12, wherein the at least one image sensor comprises a first image sensor and a second image sensor, the first image sensor being configured to receive the second portion of the first image light, and the second image sensor being configured to receive the fourth portion of the second image light.

14. The display system of claim 12, wherein the at least one image sensor comprises a single image sensor, and the display system further comprises: First shot; Second shot; Third shot; as well as A partial reflection beamsplitter, wherein a first mirror is configured to reflect a second portion of the first image light toward a second mirror, the second mirror is configured to reflect the second portion of the first image light toward the partial reflection beamsplitter, a third mirror is configured to reflect the fourth portion of the second image light toward the partial reflection beamsplitter, and the partial reflection beamsplitter is configured to guide the second portion of the first image light and the fourth portion of the second image light toward the single image sensor.

15. The display system of claim 10, wherein the optical alignment sensor comprises: A first light emitter, configured to emit first infrared light; The first set of retroreflection gratings is on the first waveguide and is configured to diffract the first infrared light; A second light emitter, configured to emit a second infrared light; The second set of retroreflection gratings is on the second waveguide and is configured to diffract the second infrared light; A first set of optical reflection sensors is located on the first waveguide and is configured to generate a first set of voltages based on a reflected version of the first infrared light diffracted by the first set of retroreflection gratings. as well as A second set of optical reflection sensors, located on the second waveguide and configured to generate a second set of voltages based on a reflected version of the second infrared light diffracted by the second set of retroreflection gratings, wherein the control circuitry is configured to control the alignment structure to mechanically adjust the position of the optical axis relative to the first waveguide based on the first set of voltages and the second set of voltages.

16. A display system, comprising: A first display module, configured to generate a first image light; A second display module, configured to generate a second image light; A first waveguide having a first output coupler and a second output coupler, wherein the first output coupler is configured to couple a first portion of a first image light out of the first waveguide. A second waveguide having a third output coupler and a fourth output coupler, wherein the third output coupler is configured to couple a first portion of the second image light out of the second waveguide; The housing portion couples the first waveguide to the second waveguide; An optical alignment sensor is provided in the housing portion, wherein a second output coupler is configured to couple a second portion of the first image light out of the first waveguide and toward the optical alignment sensor in the housing portion, wherein a fourth output coupler is configured to couple a second portion of the second image light out of the second waveguide and toward the optical alignment sensor in the housing portion, and wherein the optical alignment sensor is configured to generate image sensor data based on the second portion of the first image light and the second portion of the second image light. as well as A control circuit configured to identify the position of the first image light relative to the second image light based on the image sensor data generated by the optical alignment sensor.

17. The display system of claim 16, wherein the control circuitry is configured to mechanically adjust the first display module to compensate for the identified optical misalignment.

18. The display system of claim 17, wherein the control circuitry is configured to mechanically adjust the second display module to compensate for the identified optical misalignment.

19. The display system of claim 16, wherein the control circuit is configured to change a subset of the pixels used by the first display module to generate the first image light to compensate for the identified optical misalignment.

20. A display system, comprising: An outer casing, the outer casing having a first outer casing portion and a second outer casing portion; A display module is located in the first housing portion and configured to generate image light, wherein the display module has a collimating optics configured to transmit the image light and wherein the collimating optics has an optical axis; A waveguide, which is located in the second housing portion and configured to guide the image light; An infrared light emitter, which is located in the first housing portion and configured to emit infrared light; A set of retroreflection gratings, the set of retroreflection gratings being in the second housing portion and configured to reflect the infrared light; A set of optical sensors, which are located in the second housing portion and configured to generate a voltage based on reflected infrared light; as well as A control circuit configured to mechanically adjust the orientation of the optical axis based on the voltage generated by the set of optical sensors.

Images