Insertion-free prescription correction optical module

Abstract

The invention relates to an insertion-free prescription correction optical module. An optical module includes an electronic display configured to project image light along an optical axis, and a lens assembly aligned with the optical axis, the lens assembly including: (i) a primary optical element having a cylindrical surface profile defining a primary cylindrical axis, the main cylindrical surface axis can be rotatably aligned with a first direction; and (ii) an auxiliary optical element having a cylindrical surface profile defining an auxiliary cylindrical axis, the auxiliary cylindrical axis being rotatably alignable with the second direction. Astigmatism correction of the optical module may be accomplished by independent rotation and alignment of the primary and secondary optical elements having respective correction settings.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. non-provisional patent application No. 18 / 529,317 filed on December 5, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to optical modules that can provide adjustable accommodation, devices including respective optical modules, and related methods or apparatus. Background Art

[0004] Head-mounted displays (HMDs) have been increasingly used for various purposes including video playback, sports, and gaming. Summary of the invention

[0005] According to one aspect of the present disclosure, an optical module is provided, which includes: an electronic display configured to project image light along an optical axis; and a lens assembly aligned with the optical axis, the lens assembly including: a primary optical element having a cylindrical surface profile defining a primary cylindrical axis, the primary cylindrical axis being rotatably aligned with a first direction; and an auxiliary optical element having a cylindrical surface profile defining an auxiliary cylindrical axis, the auxiliary cylindrical axis being rotatably aligned with a second direction.

[0006] According to another aspect of the present disclosure, a pancake lens is provided, comprising: a primary optical element, which is configured to receive image light from a display, the primary optical element being configured to be rotatable around an optical axis and comprising a primary cylindrical surface profile; and a secondary optical element, which is configured to receive the image light from the primary optical element, the secondary optical element being configured to be rotatable around the optical axis and comprising a secondary cylindrical surface profile.

[0007] According to yet another aspect of the present disclosure, a method is provided, the method comprising: directing image light along an optical axis and passing through a pancake lens, the pancake lens comprising a primary optical element having a primary cylindrical surface profile and a secondary optical element having a secondary cylindrical surface profile; rotatably aligning the primary optical element with a first direction; and rotatably aligning the secondary optical element with a second direction to provide astigmatism correction for the image light. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The accompanying drawings illustrate many exemplary embodiments and are a part of the specification. Together with the following description, these drawings demonstrate and explain various principles of the present disclosure.

[0009] Figure 1A is a simplified cross-sectional view of an example optical module including a pancake lens, according to some embodiments.

[0010] Figure 1B is a simplified cross-sectional diagram of an example optical module including a pancake lens and a plane wave plate, according to some embodiments.

[0011] Figure 1C is a simplified cross-sectional diagram of an example optical module including a pancake lens and a bent wave plate, according to some embodiments.

[0012] Figure 2 An optical path through an example pancake lens is shown in accordance with certain embodiments.

[0013] Figure 3 is a schematic cross-sectional view of a variable prescription pancake lens architecture according to some embodiments.

[0014] Figure 4 is a schematic cross-sectional view of a variable prescription pancake lens architecture according to other embodiments.

[0015] Figure 5 is an illustration of exemplary augmented reality glasses that may be used in conjunction with embodiments of the present disclosure.

[0016] Figure 6 is an illustration of an exemplary virtual reality head-mounted viewer (headset) that can be used in conjunction with embodiments of the present disclosure.

[0017] In all drawings, the same reference numerals and descriptions represent similar but not necessarily identical elements. Although the exemplary embodiments described herein have various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings, and these specific embodiments will be described in detail herein. However, the exemplary embodiments described herein are not intended to be limited to the specific forms disclosed. Instead, the present disclosure encompasses all modifications, equivalents, and alternatives that fall within the scope of the appended claims. DETAILED DESCRIPTION

[0018] The present disclosure generally relates to optical modules that can provide adjustable focus, devices including the respective optical modules, and related methods or apparatuses. As explained in more detail herein, embodiments of the present disclosure may include optical modules suitable for virtual reality systems and / or augmented reality systems.

[0019] The optical module may include one or more lenses with adjustable focus. Examples include lens assemblies with variable focus, lenses including compact lenses, lenses with relatively wide focus ranges, and lenses with variable cylinders or constant cylinders. Example lens architectures may provide a specified lens correction for a user (e.g., a user of an AR / VR device including a head-mounted augmented reality / virtual reality (AR / VR) device).

[0020] Head-mounted displays (HMDs) have been increasingly used for a variety of purposes, including video playback, sports, and gaming, and are ubiquitous in virtual reality (VR) devices and headsets, augmented reality (AR) devices and headsets, and mixed reality (MR) devices and headsets, where, advantageously, the displays can be compact and lightweight, and configured to provide high-resolution images and a large field of view (FOV).

[0021] A head-mounted display generally includes a display element configured to generate or modify image light that is directed through a lens system to a user's eye. The lens system may include multiple optical elements, such as lenses, wave plates, reflectors, etc., for directing and focusing light. In order to achieve a compact form factor while maintaining desired optical properties, a pancake lens may be incorporated into the lens system of a head-mounted display.

[0022] Pancake lenses are typically flat, relatively thin components that are primarily used to provide high-quality optics in a compact package. Using polarizing and reflective elements, light can be directed back and forth multiple times along an optical path within a pancake lens. This approach, known as pancake optics or folded optics, allows the lens and display to be located in very close proximity, resulting in a more compact system. In some embodiments, a pancake optical module may include or constitute a catadioptric optical system.

[0023] To accommodate users who require vision correction, additional optical elements may be added to the pancake optical module. However, these additional elements may increase thickness and weight as well as design integration and supply chain complexity since each prescription may have a unique geometry. Despite recent developments, it would be advantageous to provide a pancake lens architecture having prescription corrections that include tunable astigmatism correction.

[0024] According to certain embodiments, individual lens elements in an optical lens assembly can be configured to include cylindrical power overlaid on a nominal spherical power or aspherical power. This approach avoids the use of separate, discrete focusing elements to correct for astigmatism. The magnitude of the cylindrical power in each lens element can be approximately 2.5 diopters. For example, the optical lens assembly can include a pair of such lens elements aligned along a common optical axis. The optical lens assembly can be located proximate to a display and configured to transmit image light from the display to a user.

[0025] The first lens element and the second lens element including a fixed cylindrical power can be independently rotatable relative to the optical axis of the lens assembly. The orientation of the lens elements can be set by the user before or during use to provide prescription correction. Specifically, the relative orientation of the first lens element and the second lens element can be set to tune the astigmatism correction, while the absolute orientation of the lens pair relative to a fixed datum can control the effective cylindrical axis of the applied cylindrical optical power. For example, the actuation of the lens elements can be manual or driven by a motor.

[0026] According to an exemplary embodiment, an optical module includes an electronic display and a lens assembly, the electronic display being configured to project image light along an optical axis, the lens assembly being aligned with the optical axis, the lens assembly including: (i) a primary optical element having a cylindrical surface profile defining a primary cylinder axis, the primary cylinder axis being rotatably alignable with a first direction; and (ii) a secondary optical element having a cylindrical surface profile defining a secondary cylinder axis, the secondary cylinder axis being rotatably alignable with a second direction. The optical element may be formed of any suitable material, including an optical grade organic component or an inorganic component, such as polycarbonate.

[0027] A method includes directing image light along an optical axis and through a pancake lens comprising a primary optical element having a primary cylindrical surface profile and a secondary optical element having a secondary cylindrical surface profile; rotatably aligning the primary optical element with a first orientation; and rotatably aligning the secondary optical element with a second orientation to provide astigmatism correction for the image light.

[0028] Features from any of the embodiments described herein may be used in combination with each other according to the general principles described herein. These and other embodiments, features and advantages will be more fully understood after reading the following detailed description in conjunction with the accompanying drawings and claims.

[0029] The following will refer to Figures 1A to 6Provides a detailed description of the prescription corrective optical module and its method of operation. Figures 1A to 4 The associated discussion includes a description of a pancake lens architecture having adjustable cylindrical power and featuring real-time astigmatism correction. Figure 5 and Figure 6 Exemplary augmented reality devices and virtual reality devices that may be used in conjunction with the various embodiments are shown.

[0030] Figure 1A 1 is a cross-sectional view of an optical module 100 including a pancake lens 122. The pancake lens 122 may constitute a portion of a head mounted display and may include a primary optical element 104 and a secondary optical element 106 aligned with a common optical axis and spatially offset by a gap (g). The primary and secondary optical elements are configured to direct light 107 emitted from an electronic display 108 to an exit pupil 110 where an eye 112 of a user is positioned. For purposes of illustration, Figure 1A A cross section of a pancake lens 122 is shown associated with a single eye 112, but the head mounted display may include Figure 1A A second pancake lens separated from the pancake lens 122 shown in FIG. 1 is provided to provide light from the electronic display that is directed by the second pancake lens to the user's other eye.

[0031] Light 107 emitted from electronic display 108 can be linearly polarized. In some embodiments, electronic display 108 can include one or more linear polarizers configured to polarize light emitted from electronic display 108. Alternatively, light emitted from a light emitting component (e.g., an LED) of electronic display 108 can be emitted as linearly polarized light.

[0032] One or more surfaces of the primary optical element 104 and the secondary optical element 106 can be shaped to correct for field curvature. For example, one or more surfaces of the primary optical element 104 and / or the secondary optical element 106 can be spherically concave, spherically convex, aspherically concave, aspherically convex, freeform, or other shapes suitable for mitigating field curvature. In some embodiments, the shape of one or more surfaces of the primary optical element 104 and the secondary optical element 106 can be designed to additionally correct for other forms of optical aberrations. As further disclosed herein, for example, cylindrical power can be co-integrated with nominal spherical power or aspherical power. In some embodiments, one or more of the optical elements (e.g., the primary optical element 104 and the secondary optical element 106) within the pancake lens 122 can include one or more coatings (e.g., anti-reflective coatings) to reduce ghosting and enhance contrast.

[0033] As shown, the primary optical element 104 and the secondary optical element 106 can be characterized as meniscus lenses, each having a convex surface and an opposite concave surface. In an exemplary embodiment, the primary optical element 104 and the secondary optical element 106 can each include a mirrored surface and an opposite wave plate surface, although alternative configurations can be envisioned.

[0034] In an exemplary embodiment, the primary optical element 104 may include a wave plate surface 130 near its convex side facing the electronic display 108 and a mirror surface 132 near its concave side, and the secondary optical element 106 may include a wave plate surface 140 near its convex side facing the electronic display 108 and a mirror surface 142 near its concave side. The wave plate surfaces 130, 140 and the mirror surfaces 132, 142 may include separate layers bonded to or formed on corresponding portions of the corresponding optical elements. In some instances, the above-described positions of the wave plate surfaces and the mirror surfaces relative to the convex and concave surfaces of each optical element may be reversed.

[0035] Wave plate surface 130 and wave plate surface 140 may each include an element configured to change the polarization of incident light. For example, a quarter wave plate may be configured to convert linearly polarized light to circularly polarized light, or circularly polarized light to linearly polarized light, and may be formed of a birefringent material such as quartz or liquid crystal.

[0036] In some embodiments, mirror 132 may include a half-mirror that partially reflects the received light. Mirror 132 may be configured to, for example, transmit 50% of the incident light and reflect 50% of the incident light. Mirror 142 may include a reflective polarizer that is configured to reflect incident light of a first polarization and transmit incident light of a second polarization. For example, mirror 142 may be configured to reflect linearly polarized light having a polarization direction in the x-direction and to pass linearly polarized light in the y-direction.

[0037] In some embodiments, the wave plate surface 130 of the primary optical element and the wave plate surface 140 of the secondary optical element may be concentric or substantially concentric. The concentric curvature may increase the expected light flux, suppress stray light, and improve the overall contrast of the image viewed by the user. Figure 2 The operation of the pancake lens 122 is discussed.

[0038] refer to Figure 1B , Figure 1B 1 shows a cross-sectional view of an optical module 150 that includes a pancake lens 152 and also includes a plane wave plate 160 disposed proximate to the convex surface of the primary optical element 104. That is, Figure 1B Pancake lens 152 with Figure 1A1 is similar to the pancake lens 122, except that the pancake lens 152 does not include a co-integrated wave plate surface 130, but instead includes a separate plane wave plate 160. For example, the plane wave plate 160 may include a 50-50 mirror.

[0039] refer to Figure 1C , Figure 1C A cross-sectional view of an optical module 170 is shown that includes a pancake lens 172 and also includes a non-planar wave plate 180 disposed proximate to the convex surface of the primary optical element 104 . Figure 1C Pancake lens 172 with Figure 1B The pancake lens 152 is similar to the pancake lens 172 , except that the pancake lens 172 includes a non-planar wave plate 180 (eg, a discrete curved wave plate) instead of a discrete planar wave plate 160 .

[0040] The non-planar wave plate 180 may have a shape that matches or substantially matches the shape of the primary optical element 104. For example, the non-planar wave plate 180 and the primary optical element 104 may be concentric or substantially concentric. Figure 1B The plane wave plate, Figure 1C The non-planar wave plate 180 (eg, a curved wave plate) in the embodiment may advantageously increase the intended light flux, suppress stray light, and improve the overall contrast of the image light viewed by the user.

[0041] refer to Figure 2 , Figure 2 Shows light passing through Figure 1A 122. In the illustrated embodiment, light 205 emitted from the electronic display 108 can be linearly polarized and directed toward the wave plate surface 130. The orientation of the wave plate axis relative to the incident linearly polarized light affects the handedness of the emitted circularly polarized light. For example, the wave plate surface 130 can include a quarter wave plate having an axis oriented at 45° relative to the polarization direction of the light 205, so that the wave plate surface 130 changes the linearly polarized light 205 into circularly polarized light 210. The polarization of the light 210 can be clockwise or counterclockwise.

[0042] A first portion of light 210 may be reflected by mirror 132, while a second portion of light 215 may be transmitted through mirror 132 toward secondary optical element wave plate surface 140. In some embodiments, mirror 132 may be configured to reflect 50% of incident light.

[0043] The wave plate surface 140 of the auxiliary optical element may include a quarter wave plate configured to change the circularly polarized light 215 into linearly polarized light 220. In turn, the light 220 is incident on the mirror surface 142 (hereinafter also referred to as the reflective polarizer surface 142), which may be configured to reflect light polarized in the blocking direction (e.g., the x direction) and transmit light polarized in the perpendicular direction (e.g., the y direction). The reflected light 225 is directed back to the wave plate surface 140, which changes the linearly polarized light 225 into circularly polarized light 230 and directs it toward the mirror surface 132, which again reflects a portion of the polarized light 230 into a light beam (e.g., light 235).

[0044] Light 235 may be circularly polarized, but the handedness of the circularly polarized light is opposite to the handedness of light 230 and light 215 due to reflection from mirror surface 132. Wave plate surface 140 changes the polarization of circularly polarized light 235 to linearly polarized light 240. However, since the handedness of light 235 is opposite to the handedness of light 215, the polarization of light 240 is perpendicular to the polarization of light 220. Therefore, light 240 may be linearly polarized in a direction perpendicular to the blocking direction of reflective polarizer surface 142, and thus may be transmitted by reflective polarizer surface 142 to exit pupil 250 as light 245. Therefore, light propagating through pancake lens 122 may experience multiple reflections between secondary optical element 106 and primary optical element 104.

[0045] Go to Figure 3 , the pancake lens 300 may include a primary optical element 104 configured to receive image light from an electronic display 108 and a secondary optical element 106 configured to receive image light from the primary optical element 104. The primary optical element 104 is configured to be rotatable about an optical axis 107 and may include a primary cylindrical surface profile, and the secondary optical element 106 is configured to be rotatable about the optical axis 107 and may include a secondary cylindrical surface profile. For example, cylindrical power may be co-integrated into each convex surface of the primary optical element and the secondary optical element.

[0046] The primary optical element 104 and the secondary optical element 106 may be bilaterally symmetrical and separated from each other, for example, by an air gap (g). According to certain embodiments, the spacing between these optical elements may be arranged so that the primary optical element 104 and the secondary optical element 106 may be independently rotated about the optical axis 107. For example, each of the primary optical element 104 and the secondary optical element 106 may be freely and reversibly rotated through an angular range of 0 to 2π radians. Astigmatism correction may be achieved by rotating the primary optical element and the secondary optical element to a predetermined inter-element angular relationship and aligning the oriented optical element pair to another relationship with a fixed reference point.

[0047] In some embodiments, the spacing between the primary optical element 104 and the secondary optical element 106 along the optical axis 107 can be adjustable. That is, the gap (g) can be set to a desired value. In addition, the position of the primary optical element 104 and / or the secondary optical element 106 along the optical axis 107 can be set to adjust the working distance (WD) between the pancake lens 300 and the electronic display 108. As will be appreciated, the overall optical power (i.e., focal length) of the pancake lens can be tuned by adjusting one or more of the spacing between the primary and secondary optical elements and the working distance between the pancake lens and the electronic display.

[0048] In the illustrated embodiment, the primary optical element 104 and the secondary optical element 106 can each include an aspheric surface profile, wherein each corresponding cylindrical surface profile is merged with a corresponding aspheric surface profile. The cylindrical surface profile of the primary optical element 104 and the cylindrical surface profile of the secondary optical element 106 can each include a refractive cylindrical power of approximately 2.5 diopters, although smaller and larger values ​​are also contemplated. The primary optical element 104 and the secondary optical element 106 can each include a meniscus lens.

[0049] According to other embodiments, the tunable cylindrical power and associated optical elements can be incorporated into an optical module independently of the folded optics. Such a configuration can advantageously decouple astigmatism correction from the lens power used to correct hyperopia or myopia. For example, the optical module can include separate spherical and cylindrical elements, which can simplify and improve polarization dynamics in some embodiments.

[0050] In this case, go to Figure 4 , the pancake lens 400 includes a primary optical element 104 and a secondary optical element 106 configured to receive image light from the primary optical element 104. Figure 3 As in the embodiment of the present invention, the primary optical element 104 may include, for example, a wave plate and a 50-50 mirror formed on opposite surfaces, and the secondary optical element 106 may include, for example, a wave plate and a reflective polarizer formed on opposite surfaces.

[0051] exist Figure 4In an embodiment of the present invention, the additional optical element 102 can be located between the primary optical element 104 and the electronic display 108, i.e., outside the cavity of the pancake lens 400. The cylindrical power can be co-integrated into the surface of each of the optical element 102 and the primary optical element 104, and the optical element 102 and the primary optical element 104 can be independently rotatable about the optical axis 107. The cylindrical power and orientation can be tuned by setting the relative and absolute orientations of the optical element 102 and the primary optical element 104, respectively, while avoiding rotation of the auxiliary optical element 106 and its accompanying polarization-sensitive components.

[0052] As disclosed herein, a pancake optical module can be configured to provide astigmatism correction without adding additional optical elements to the optical module. An exemplary optical module includes a pair of inline optical elements, each having complementary 2.5D cylindrical surfaces. The optical power and angle of astigmatism can be easily tuned by rotating the relative and absolute angles of these 2.5D surfaces relative to a fixed reference. That is, the amount of cylindrical power can be tuned by adjusting the relative angular relationship between the optical elements, while the overall position of the optical elements (e.g., relative to a fixed point such as a user's eye) can change the effective axis of the cylindrical power. This configuration adds minimal TTL to the device (e.g., a head-mounted viewer) and allows the user to make prescription adjustments without introducing any additional elements to the optical module.

[0053] Example Embodiments

[0054] Example 1: An optical module includes an electronic display and a lens assembly, the electronic display being configured to project image light along an optical axis, the lens assembly being aligned with the optical axis, the lens assembly comprising: (i) a primary optical element having a cylindrical surface profile defining a primary cylindrical axis, the primary cylindrical axis being capable of being rotatably aligned in a first direction; and (ii) a secondary optical element having a cylindrical surface profile defining a secondary cylindrical axis, the secondary cylindrical axis being capable of being rotatably aligned in a second direction.

[0055] Example 2: An optical module according to Example 1, wherein the primary optical element and the secondary optical element are capable of independently rotating around the optical axis.

[0056] Example 3: An optical module according to any one of Examples 1 and 2, wherein the primary optical element and the auxiliary optical element each include an aspheric surface profile, and the corresponding cylindrical surface profiles of the primary optical element and the auxiliary optical element are merged with the corresponding aspheric surface profiles of the primary optical element and the auxiliary optical element.

[0057] Example 4: An optical module according to any one of Examples 1 to 3, wherein the primary optical element and the auxiliary optical element are each bilaterally symmetrical.

[0058] Example 5: An optical module according to any one of Examples 1 to 4, wherein the cylindrical surface profile of the primary optical element and the cylindrical surface profile of the auxiliary optical element each include a cylindrical optical power of approximately 2.5D.

[0059] Example 6: An optical module according to any one of Examples 1 to 5, wherein the main cylindrical axis is configured to be aligned with the first direction by a user, and the auxiliary cylindrical axis is configured to be aligned with the second direction by the user.

[0060] Example 7: An optical module according to any one of Examples 1 to 6, wherein the first direction and the second direction are substantially orthogonal to the optical axis.

[0061] Example 8: An optical module according to any one of Examples 1 to 7, wherein the lens assembly includes a pancake lens.

[0062] Example 9: An optical module according to any one of Examples 1 to 8, wherein the primary optical element and the secondary optical element each include a meniscus lens.

[0063] Example 10: An optical module according to any one of Examples 1 to 9, wherein the primary optical element is spaced apart from the secondary optical element.

[0064] Example 11: An optical module according to any one of Examples 1 to 10, wherein the primary optical element is separated from the secondary optical element by an air gap.

[0065] Example 12: An optical module according to any one of Examples 1 to 11, wherein a spacing between the primary optical element and the secondary optical element along the optical axis is adjustable.

[0066] Example 13: An optical module according to any one of Examples 1 to 12, wherein a working distance between the lens assembly and the electronic display is adjustable.

[0067] Example 14: An optical module according to any one of Examples 1 to 13, wherein the primary optical element and the auxiliary optical element each include a mirror.

[0068] Example 15: An optical module according to any one of Examples 1 to 14, wherein the primary optical element includes a beam splitter element and the secondary optical element includes a reflective polarizer.

[0069] Example 16: A pancake lens includes: a primary optical element configured to receive image light from a display, the primary optical element configured to be rotatable about an optical axis and including a primary cylindrical surface profile; and a secondary optical element configured to receive image light from the primary optical element, the secondary optical element configured to be rotatable about the optical axis and including a secondary cylindrical surface profile.

[0070] Example 17: A pancake lens according to Example 16, wherein the primary cylindrical surface profile and the secondary cylindrical surface profile each include a cylindrical optical power of approximately 2.5D.

[0071] Example 18: A pancake lens according to any one of Examples 16 and 17, wherein the primary optical element includes a primary aspheric surface profile, and the primary cylindrical surface profile is overlaid on the primary aspheric surface profile; the auxiliary optical element includes an auxiliary aspheric surface profile, and the auxiliary cylindrical surface profile is overlaid on the auxiliary aspheric surface profile.

[0072] Example 19: A method includes: directing image light along an optical axis and passing it through a pancake lens, the pancake lens comprising a primary optical element having a primary cylindrical surface profile and a secondary optical element having a secondary cylindrical surface profile; rotatably aligning the primary optical element in a first direction; and rotatably aligning the secondary optical element in a second direction to provide astigmatism correction for the image light.

[0073] Example 20: The method of Example 19, wherein rotatably aligning the primary optical element and the secondary optical element comprises aligning the primary optical element relative to the secondary optical element, and aligning both the primary optical element and the secondary optical element relative to a fixed reference.

[0074] Embodiments of the present disclosure may include various types of artificial reality systems or be implemented in combination with various types of artificial reality systems. Artificial reality is a form of reality that has been adjusted in some way before being presented to the user, and artificial reality may include, for example, virtual reality, augmented reality, mixed reality (mixed reality or hybrid reality), or some combination and / or derivative thereof. Artificial reality content may include computer-generated content entirely or computer-generated content combined with collected (e.g., real-world) content. Artificial reality content may include video, audio, tactile feedback, or some combination thereof, and any one of video, audio, tactile feedback, or some combination thereof may be presented in a single channel or multiple channels (e.g., stereoscopic video that produces a three-dimensional (3D) effect to the viewer). Additionally, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof, which are used, for example, to create content in artificial reality and / or to be used in artificial reality in other ways (e.g., to perform activities in artificial reality).

[0075] Artificial reality systems may be implemented in a variety of different form factors and configurations. Some artificial reality systems may be designed to work without a near-eye display (NED). Other artificial reality systems may include a NED that also provides visibility to the real world (e.g., Figure 5 The augmented reality system 500 in FIG. 5 ) or an NED that visually immerses a user in an artificial reality (e.g., Figure 6 600 in the virtual reality system 600). While some artificial reality devices may be stand-alone systems, other artificial reality devices may communicate and / or cooperate with external devices to provide an artificial reality experience to a user. Examples of such external devices include handheld controllers, mobile devices, desktop computers, devices worn by a user, devices worn by one or more other users, and / or any other suitable external system.

[0076] Go to Figure 5 , the augmented reality system 500 may include an eye-mounted device 502 having a frame 510 configured to hold a left display device 515(A) and a right display device 515(B) in front of the user's eyes. The left display device 515(A) and the right display device 515(B) may function together or independently to present an image or a series of images to the user. Although the augmented reality system 500 includes two displays, embodiments of the present disclosure may be implemented in an augmented reality system having a single NED or more than two NEDs.

[0077] In some embodiments, the augmented reality system 500 may include one or more sensors, such as sensor 540. Sensor 540 may generate measurement signals in response to the movement of the augmented reality system 500, and may be located on substantially any part of the frame 510. Sensor 540 may represent a position sensor, an inertial measurement unit (IMU), a depth camera assembly, a structured light emitter and / or detector, or any combination thereof. In some embodiments, the augmented reality system 500 may or may not include sensor 540, or may include more than one sensor. In embodiments where sensor 540 includes an IMU, the IMU may generate calibration data based on the measurement signals from sensor 540. Examples of sensor 540 may include, but are not limited to, accelerometers, gyroscopes, magnetometers, other suitable types of sensors that detect movement, sensors for error correction of IMUs, or some combination thereof.

[0078] The augmented reality system 500 may also include a microphone array having a plurality of acoustic transducers 520(A) to 520(J) (collectively referred to as acoustic transducers 520). The acoustic transducers 520 may be transducers that detect changes in air pressure caused by sound waves. Each acoustic transducer 520 may be configured to detect sound and convert the detected sound into an electronic format (e.g., an analog format or a digital format). Figure 5 The microphone array in may, for example, include ten acoustic transducers: acoustic transducer 520(A) and acoustic transducer 520(B) that can be designed to be placed in the corresponding ears of the user; acoustic transducer 520(C), acoustic transducer 520(D), acoustic transducer 520(E), acoustic transducer 520(F), acoustic transducer 520(G) and acoustic transducer 520(H) that can be positioned at different positions on the frame 510; and / or acoustic transducer 520(I) and acoustic transducer 520(J) that can be positioned on the corresponding neckband 505.

[0079] In some embodiments, one or more of the acoustic transducers 520(A) to 520(F) can be used as an output transducer (e.g., a speaker). For example, the acoustic transducers 520(A) and / or 520(B) can be earbuds, or any other suitable type of earphones or speakers.

[0080] The configuration of the acoustic transducer 520 of the microphone array may vary. Figure 5520, but the number of acoustic transducers 520 may be greater than or less than ten. In some embodiments, using a greater number of acoustic transducers 520 may increase the amount of audio information collected and / or the sensitivity and accuracy of the audio information. Conversely, using a smaller number of acoustic transducers 520 may reduce the computing power required by the associated controller 550 to process the collected audio information. In addition, the position of each acoustic transducer 520 in the microphone array may vary. For example, the position of the acoustic transducer 520 may include a defined position on the user, a defined coordinate on the frame 510, an orientation associated with each acoustic transducer 520, or some combination thereof.

[0081] Acoustic transducers 520(A) and 520(B) can be located on different parts of the user's ear, such as behind the pinna, behind the tragus, and / or in the auricle or fossa. Alternatively, in addition to the acoustic transducer 520 in the ear canal, additional acoustic transducers 520 can be provided on or around the ear. Having an acoustic transducer 520 positioned next to the user's ear canal enables the microphone array to collect information about how sound reaches the ear canal. By positioning at least two acoustic transducers 520 on both sides of the user's head (e.g., as binaural microphones), the augmented reality system 500 can simulate binaural hearing and capture a 3D stereo sound field around the user's head. In some embodiments, the acoustic transducers 520(A) and 520(B) can be connected to the augmented reality system 500 via a wired connection 530, while in other embodiments, the acoustic transducers 520(A) and 520(B) can be connected to the augmented reality system 500 via a wireless connection (e.g., a Bluetooth connection). In other embodiments, acoustic transducer 520 (A) and acoustic transducer 520 (B) may not be used in conjunction with augmented reality system 500 at all.

[0082] The acoustic transducers 520 on the frame 510 can be positioned in a variety of ways: along the length of the temples, across the bridge, above or below the display devices 515(A) and 515(B), or some combination thereof. The acoustic transducers 520 can also be oriented so that the microphone array can detect sounds in a wide range of directions around the user wearing the augmented reality system 500. In some embodiments, an optimization process can be performed during the manufacture of the augmented reality system 500 to determine the relative positioning of each acoustic transducer 520 in the microphone array.

[0083] In some examples, the augmented reality system 500 may include or be connected to an external device (e.g., a paired device), such as a neckband 505. Neckband 505 generally represents any type or form of paired device. Therefore, the following discussion of neckband 505 may also be applied to various other paired devices, such as charging boxes, smart watches, smart phones, wristbands, other wearable devices, handheld controllers, tablets, laptops, other external computing devices, etc.

[0084] As shown, the neckband 505 can be coupled to the eye-mounted device 502 via one or more connectors. The connectors can be wired or wireless and can include electronic components and / or non-electronic components (e.g., structural components). In some cases, the eye-mounted device 502 and the neckband 505 can operate independently without any wired or wireless connection between them. Although Figure 5 Example locations of components of the eye-mounted device 502 and components of the neckband 505 are shown on the eye-mounted device 502 and the neckband 505, but these components can be located elsewhere on the eye-mounted device 502 and / or the neckband 505 and / or distributed on the eye-mounted device and / or the neckband in different ways. In some embodiments, components of the eye-mounted device 502 and components of the neckband 505 can be located on one or more additional peripheral devices paired with the eye-mounted device 502, on the neckband 505, or some combination thereof.

[0085] Pairing an external device (e.g., a neckband 505) with an augmented reality eye-mounted device can enable the eye-mounted device to achieve the form factor of a pair of glasses and still provide sufficient battery power and computing power for the expanded capabilities. Some or all of the battery power, computing resources, and / or additional features of the augmented reality system 500 can be provided by the paired device or shared between the paired device and the eye-mounted device, thereby reducing the weight, thermal distribution, and form factor of the eye-mounted device as a whole while still retaining the desired functionality. For example, the neckband 505 can allow components that would otherwise be included on the eye-mounted device to be included in the neckband 505 because a user can bear a heavier weight load on their shoulders than the user can bear on their head. The neckband 505 can also have a larger surface area, which can be used to spread and disperse heat to the surrounding environment. Therefore, the neckband 505 can allow for greater battery capacity and computing power than would otherwise be possible on a stand-alone eye-mounted device. Because the weight carried in the neckband 505 is less invasive to the user than the weight carried in the eye-mounted device 502, the user can tolerate wearing the lighter eye-mounted device and carrying or wearing a paired device for longer periods of time than the user can tolerate wearing a heavy stand-alone eye-mounted device, thereby enabling the user to more fully integrate the artificial reality environment into their daily activities.

[0086] The neckband 505 can be communicatively coupled to the eye-mounted device 502 and / or communicatively coupled to other devices. These other devices can provide certain functions (e.g., tracking, positioning, depth map construction, processing, storage, etc.) for the augmented reality system 500. Figure 5 In an embodiment of the present invention, neckband 505 may include two acoustic transducers (e.g., acoustic transducer 520(I) and acoustic transducer 520(J)) as part of a microphone array (or potentially forming its own microphone subarray). Neckband 505 may also include controller 525 and power supply 535.

[0087] The acoustic transducers 520(I) and 520(J) of the neckband 505 may be configured to detect sound and convert the detected sound into an electronic format (analog or digital). Figure 5In an embodiment of the present invention, the acoustic transducers 520(I) and 520(J) can be positioned on the neckband 505, thereby increasing the distance between the acoustic transducers 520(I) and 520(J) of the neckband and other acoustic transducers 520 located on the eye-mounted device 502. In some cases, increasing the distance between the acoustic transducers 520 of the microphone array can improve the accuracy of the beamforming performed via the microphone array. For example, if a sound is detected by the acoustic transducers 520(C) and 520(D), and the distance between the acoustic transducers 520(C) and 520(D) is greater than, for example, the distance between the acoustic transducers 520(D) and 520(E), then the determined source location of the detected sound can be more accurate than the source location determined when the sound is detected by the acoustic transducers 520(D) and 520(E).

[0088] The controller 525 of the neckband 505 can process information generated by sensors on the neckband 505 and / or the augmented reality system 500. For example, the controller 525 can process information from the microphone array that describes the sound detected by the microphone array. For each detected sound, the controller 525 can perform a Direction-of-Arrival (DOA) estimate to estimate from which direction the detected sound arrives at the microphone array. When the microphone array detects a sound, the controller 525 can fill the audio data set with information. In an embodiment where the augmented reality system 500 includes an inertial measurement unit, the controller 525 can calculate all inertial and spatial operations based on the IMU located on the eye-mounted device 502. The connector can transmit information between the augmented reality system 500 and the neckband 505, and between the augmented reality system 500 and the controller 525. The information can be in the form of optical data, electronic data, wireless data, or any other transmittable data form. Moving the processing of information generated by the augmented reality system 500 to the neckband 505 can reduce the weight and heat of the eye-mounted device 502, making it more comfortable for the user.

[0089] The power source 535 in the neckband 505 can provide power to the eye-mounted device 502 and / or to the neckband 505. The power source 535 can include, but is not limited to, a lithium-ion battery, a lithium-polymer battery, a disposable lithium battery, an alkaline battery, or any other form of power storage device. In some cases, the power source 535 can be a wired power source. Including the power source 535 on the neckband 505 instead of the eye-mounted device 502 can help to better distribute the weight and heat generated by the power source 535.

[0090] As noted, some artificial reality systems may substantially replace one or more of a user's multiple sensory perceptions of the real world with a virtual experience, rather than blending the artificial reality with the real reality. An example of this type of system is a head-mounted display system that covers most or all of the user's field of view, e.g. Figure 6 6. The virtual reality system 600 may include a front rigid body 602 and a band 604 shaped to fit around the user's head. The virtual reality system 600 may also include output audio converters 606 (A) and 606 (B). Figure 6 , but the front rigid body 602 may include one or more electronic components, including one or more electronic displays, one or more inertial measurement units (IMUs), one or more tracking transmitters or detectors, and / or any other suitable device or system for creating an artificial reality experience.

[0091] Artificial reality systems may include various types of visual feedback mechanisms. For example, the display device in the augmented reality system 500 and / or the display device in the virtual reality system 600 may include one or more liquid crystal displays (LCD), one or more light emitting diodes (LED) displays, one or more organic LED (OLED) displays, one or more digital light projection (DLP) micro displays, one or more liquid crystal on silicon (LCoS) micro displays, and / or any other suitable type of display screen. These artificial reality systems may include a single display screen for both eyes, or a display screen may be provided for each eye, which may provide additional flexibility for zoom adjustment or correction of the user's refractive error. Some artificial reality systems may also include an optical subsystem having one or more lenses (e.g., conventional concave or convex lenses, Fresnel lenses, adjustable liquid lenses, etc.), through which the user can view the display screen. These optical subsystems can be used for a variety of purposes, including collimating light (e.g., making an object appear at a greater distance than it is physically at), amplifying light (e.g., making an object appear larger than its actual size), and / or relaying light (e.g., to a viewer's eye). These optical subsystems can be used in a direct-view architecture (e.g., a single lens configuration that directly collimates light but results in so-called pincushion distortion) and / or a non-direct-view architecture (e.g., a multi-lens configuration that produces so-called barrel distortion to eliminate pincushion distortion).

[0092] In addition to or in lieu of using a display screen, some artificial reality systems may include one or more projection systems. For example, a display device in the augmented reality system 500 and / or a display device in the virtual reality system 600 may include a micro-LED projector that projects light (e.g., using a waveguide) into the display device, such as a transparent combined lens that allows ambient light to pass through. The display device may refract the projected light toward the user's pupil, and may enable the user to view both the artificial reality content and the real world simultaneously. The display device may achieve this using any of a variety of different optical components, including waveguide components (e.g., holographic waveguide elements, planar waveguide elements, diffractive waveguide elements, polarizing waveguide elements, and / or reflective waveguide elements), light manipulation surfaces and elements (e.g., diffractive elements and gratings, reflective elements and gratings, and refractive elements and gratings), coupling elements, and the like. The artificial reality system may also be configured with any other suitable type or form of image projection system, such as a retinal projector used in a virtual retinal display.

[0093] The artificial reality system may also include various types of computer vision components and subsystems. For example, the augmented reality system 500 and / or the virtual reality system 600 may include one or more optical sensors, such as a two-dimensional (2D) camera or a 3D camera, a structured light emitter and detector, a time-of-flight depth sensor, a single beam rangefinder or a scanning laser rangefinder, a 3D laser radar (LiDAR) sensor, and / or any other suitable type or form of optical sensor. The artificial reality system may process data from one or more of these sensors to identify the user's location, map the real world, provide content about the real world environment to the user, and / or perform various other functions.

[0094] The artificial reality system may also include one or more input audio converters and / or output audio converters. Figure 6 In the example shown, output audio transducers 606(A) and 606(B) may include voice coil speakers, ribbon speakers, electrostatic speakers, piezoelectric speakers, bone conduction transducers, cartilage conduction transducers, tragus vibration transducers, and / or any other suitable type or form of audio transducers. Similarly, input audio transducers may include condenser microphones, dynamic microphones, ribbon microphones, and / or any other type or form of input transducers. In some embodiments, a single transducer may be used for both audio input and audio output.

[0095] Despite Figure 5Not shown, but the artificial reality system may also include a tactile (i.e., haptic) feedback system that may be incorporated into headwear, gloves, clothing, handheld controllers, environmental devices (e.g., chairs, floor mats, etc.), and / or any other type of device or system. The tactile feedback system may provide various types of skin feedback including vibration, force, traction, texture, and / or temperature. The tactile feedback system may also provide various types of kinesthetic feedback, such as motion and compliance. Tactile feedback may be implemented using motors, piezoelectric actuators, fluid systems, and / or various other types of feedback mechanisms. The tactile feedback system may be implemented independently of other artificial reality devices, within other artificial reality devices, and / or in combination with other artificial reality devices.

[0096] By providing tactile perception, auditory content, and / or visual content, artificial reality systems can create complete virtual experiences or enhance users' real-world experiences in various situations and environments. For example, artificial reality systems can assist or expand users' perception, memory, or cognition in a specific environment. Some systems can enhance users' interactions with other people in the real world, or can enable more immersive interactions with other people in the virtual world. Artificial reality systems can also be used for educational purposes (e.g., for teaching or training in schools, hospitals, government organizations, military organizations, commercial enterprises, etc.), entertainment purposes (e.g., for playing video games, listening to music, watching video content, etc.), and / or for access purposes (e.g., as hearing aids, visual aids, etc.). The embodiments disclosed herein can implement or enhance users' artificial reality experiences in one or more of these situations and environments, and / or in other situations and environments.

[0097] The process parameters and order of steps described and / or illustrated herein are given as examples only and may be changed as desired. For example, although the steps illustrated and / or described herein may be shown or discussed in a particular order, the steps do not necessarily need to be performed in the order shown or discussed. The various exemplary methods described and / or illustrated herein may also omit one or more of the steps described or illustrated herein, or include additional steps in addition to those disclosed steps.

[0098] The foregoing description is provided to enable others skilled in the art to best utilize the various aspects of the exemplary embodiments disclosed herein. This exemplary description is not intended to be exhaustive or limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the present disclosure. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. In determining the scope of the present disclosure, reference should be made to any claims attached and their equivalents.

[0099] Unless otherwise indicated, the terms "connected to" and "coupled to" (and their derivatives) as used in the specification and / or claims should be interpreted as allowing both direct and indirect (i.e., via other elements or components) connections. In addition, the terms "a" or "an" as used in the specification and / or claims are interpreted to mean "at least one of..." Finally, for ease of use, the terms "including" and "having" (and their derivatives) as used in the specification and / or claims are interchangeable with the word "comprising" and have the same meaning.

[0100] It should be understood that when an element (e.g., a layer or region) is referred to as being formed on, deposited on, or disposed “on” or “over” another element, the element may be directly on at least a portion of the other element, or one or more intermediate elements may also be present. Conversely, when an element is referred to as being “directly on” or “directly over” another element, the element may be on at least a portion of the other element without the presence of intermediate elements.

[0101] As used herein, in certain embodiments, the term "about" with respect to a particular value or range of values ​​may refer to and include the value and all values ​​within 10% of the value. Thus, for example, in certain embodiments, the value "50" may be referred to as "about 50," including values ​​equal to 50±5, i.e., values ​​within the range of 45 to 55.

[0102] As used herein, the term "substantially" with respect to a given parameter, property, or condition can refer to and include the degree to which one skilled in the art will understand that the given parameter, property, or condition is satisfied to a lesser degree (e.g., within acceptable manufacturing tolerances). For example, depending on the particular parameter, property, or condition that is substantially satisfied, the parameter, property, or condition may be at least about 90% satisfied, at least about 95% satisfied, or even at least about 99% satisfied.

[0103] Although the transition phrase "comprising" may be used to disclose various features, elements, or steps of a particular embodiment, it should be understood that alternative embodiments (including embodiments that may be described using the transition phrases "consisting of" or "consisting essentially of") are implied. Thus, for example, implicit alternative embodiments of a lens element that comprises or includes polycarbonate include embodiments in which the lens element consists essentially of polycarbonate and embodiments in which the lens element consists of polycarbonate.

Claims

1. An optical module, comprising: an electronic display configured to project image light along an optical axis; as well as a lens assembly aligned with the optical axis, the lens assembly comprising: a primary optical element having a cylindrical surface profile defining a primary cylindrical axis, the primary cylindrical axis being rotatably alignable with a first direction; as well as A secondary optical element has a cylindrical surface profile defining a secondary cylindrical axis that is rotatably alignable with the second direction.

2. The optical module according to claim 1, wherein: The primary optical element and the secondary optical element are independently rotatable about the optical axis.

3. The optical module according to claim 1, wherein: The primary optical element and the secondary optical element each include an aspheric surface profile, and the respective cylindrical surface profiles of the primary optical element and the secondary optical element are merged with the respective aspheric surface profiles of the primary optical element and the secondary optical element.

4. The optical module according to claim 1, wherein: The primary optical element and the secondary optical element are each bilaterally symmetrical.

5. The optical module according to claim 1, wherein: The cylindrical surface profile of the primary optical element and the cylindrical surface profile of the secondary optical element each include a cylindrical optical power of approximately 2.5D.

6. The optical module according to claim 1, wherein: The primary cylindrical axis is configured to be aligned with the first direction by a user, and the secondary cylindrical axis is configured to be aligned with the second direction by the user.

7. The optical module according to claim 1, wherein: The first direction and the second direction are substantially orthogonal to the optical axis.

8. The optical module according to claim 1, wherein: The lens assembly includes a pancake lens.

9. The optical module according to claim 1, wherein: The primary optical element and the secondary optical element each include a meniscus lens.

10. The optical module according to claim 1, wherein: The primary optical element is spaced apart from the secondary optical element.

11. The optical module according to claim 1, wherein: The primary optical element is spaced apart from the secondary optical element by an air gap.

12. The optical module according to claim 1, wherein: A spacing between the primary optical element and the secondary optical element along the optical axis is adjustable.

13. The optical module according to claim 1, wherein: A working distance between the lens assembly and the electronic display is adjustable.

14. The optical module according to claim 1, wherein: The primary optical element and the secondary optical element each include a mirror surface.

15. The optical module according to claim 1, wherein: The primary optical element comprises a beam splitter element and the secondary optical element comprises a reflective polarizer.

16. A pancake lens, comprising: a primary optical element configured to receive image light from a display, the primary optical element configured to be rotatable about an optical axis and comprising a primary cylindrical surface profile; as well as A secondary optical element is configured to receive the image light from the primary optical element, the secondary optical element being configured to be rotatable about the optical axis and comprising a secondary cylindrical surface profile.

17. The pancake lens according to claim 16, wherein: The primary cylindrical surface profile and the secondary cylindrical surface profile each include a cylindrical power of approximately 2.5D.

18. The pancake lens of claim 16, wherein: The primary optical element includes a primary aspheric surface profile, and the primary cylindrical surface profile overlies the primary aspheric surface profile; as well as The secondary optical element includes a secondary aspheric surface profile, and the secondary cylindrical surface profile overlies the secondary aspheric surface profile.

19. A method comprising: directing image light along an optical axis and through a pancake lens including a primary optical element having a primary cylindrical surface profile and a secondary optical element having a secondary cylindrical surface profile; rotatably aligning the primary optical element with a first orientation; as well as The secondary optical element is rotationally aligned with a second orientation to provide astigmatism correction for the image light.

20. The method according to claim 19, wherein: Rotatably aligning the primary optical element and the secondary optical element includes aligning the primary optical element relative to the secondary optical element and aligning both the primary optical element and the secondary optical element relative to a fixed reference.

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