Adjustable cylindrical lens and head-mounted display comprising the same

Abstract

The system comprises three optical elements arranged along an optical axis, each optical element having a different cylindrical axis and a variable cylindrical power. The three elements together form a composite optical element having an overall spherical power (SPH), a cylindrical power (CYL) and a cylindrical axis (Axis) which can be varied according to a prescription (Rx).

Description

[0001] Priority requirements

[0002] This application claims priority to U.S. Patent Application Serial No. 63 / 062,746, filed August 7, 2020, pursuant to 35 USC §119(e), the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to adjustable lenses, and more specifically, to head-mounted displays that include adjustable lenses to correct a user's refractive errors. Background Technology

[0004] Wearable display systems for augmented reality can include one or two eyepieces through which a user observes the world, and through which the display system can project digital images onto the user. Eyepieces are typically formed using highly refractive materials and are generally designed with users having emmetropic vision (i.e., no refractive error) in mind.

[0005] For users with amorphous vision, such as those with short vision (myopia) or far vision (hyperopia), a custom insert could be provided in the wearable display to correct the user's refractive error, for example, based on their ophthalmological prescription (Rx). Alternatively, the display's shape factor could be designed to accommodate eyeglasses between the wearer and the display's eyepiece. However, customizing a headset is both time-consuming and expensive, and shape factors that accommodate eyeglasses may not be appealing in terms of convenience or aesthetics. Summary of the Invention

[0006] The feature of this disclosure is the integration of adjustable lenses into the eyepieces of head-mounted displays for correcting anomalous vision, particularly in virtual reality head-mounted displays. The eyepiece can include fully integrated, field-configurable optics relative to a waveguide arrangement for projecting digital images to the user, capable of providing the user with adjustable Rx values, including variable spherical power (SPH), cylindrical power (CYL), and cylindrical axis (Axis) values. In some configurations, each adjustable eyepiece includes two variable compound lenses: one on the user side of the waveguide with variable spherical, cylindrical, and axis values; and a second on the world side of the waveguide with variable spherical values. In general, the variable compound lenses can correct the user's refractive errors, including astigmatism, and can position the digital image in an appropriate depth plane relative to the environment and corresponding to a fixed depth of the user.

[0007] In some embodiments, each compound lens includes multiple (e.g., two or three) variable cylindrical lenses. For example, each variable cylindrical lens may include a deformable refractive element integrated with an actuator. The actuator applies a force to the deformable refractive element to change the curvature of one or both surfaces of the lens, thereby changing the optical power of the cylindrical lens. An assembly of two such variable cylindrical lenses whose cylindrical axes are oriented at right angles can be used to provide a compound lens with adjustable spherical refractive power. An assembly of three variable cylindrical lenses whose cylindrical axes are oriented at 60° intervals can be used to provide a compound lens with adjustable SPH, CYL, and Axis.

[0008] In a first aspect, this document discloses a system comprising: a first optical element including a first refractive element arranged along an optical axis and a first actuator arranged to change the cylindrical refractive force of the first refractive element in response to a first control signal, the first refractive element having a first cylindrical axis associated with the first refractive element along a first radial direction orthogonal to the optical axis; a second optical element including a second refractive element arranged along an optical axis and a second actuator arranged to change the cylindrical refractive force of the second refractive element in response to a second control signal, the second refractive element having a second cylindrical axis associated with the second refractive element along a second radial direction orthogonal to the optical axis; and a third optical element. An optical element comprising a third refractive element arranged along an optical axis, and a third actuator arranged to change the cylindrical refractive power of the third refractive element in response to a third control signal along a third radial direction orthogonal to the optical axis, wherein the first, second, and third radial directions are different; and an electronic controller in communication with the first, second, and third actuators, the electronic controller being configured to provide the first, second, and third control signals respectively to the first, second, and third actuators during operation such that the first, second, and third refractive elements, according to a formula (Rx), collectively form an optical element having an overall spherical refractive power (SPH), a cylindrical refractive power (CYL), and a cylindrical axis (Axis).

[0009] In some embodiments, the angular separation between the first and second radial directions can be equal to the angular separation between the second and third radial directions. For a Cartesian coordinate system orthogonal to the optical axis, the first radial direction can be 30°, the second radial direction can be 90°, and the third radial direction can be 150°. The first cylindrical refractive force C 30 The refractive force C of the second cylinder 90 The refractive force C of the third cylinder 150 The values ​​of S, C, and A are related according to the following formula:

[0010]

[0011]

[0012]

[0013] At least one of the refractive elements may include a deformable optical material. The deformable optical material may be a solid optical material. The solid optical material may be an elastic material. The elastic material may be silicone rubber. At least one of the refractive elements may include a deformable transparent film adjacent to the deformable optical material, and an actuator for at least one refractive element is arranged to deform the shape of the deformable transparent film to change the cylindrical refractive force of the at least one refractive element. The actuator bends the film about the cylindrical axis of the at least one refractive element to change the cylindrical refractive force of the at least one refractive element. At least one of the refractive elements may include a rigid transparent substrate adjacent to the deformable optical material on the side of the refractive element opposite to the deformable optical material. The optical element of at least one of the refractive elements may include a rigid washer at the edge of the deformable optical material, on which the deformable transparent film pivots when acted upon by the actuator. The cylindrical refractive force of each of the first, second, and third optical elements can be varied within a range from -5D to +5D. The aperture of the optical element has a diameter of 1 cm. 2 Or a larger area. (For example, 5cm) 2 Or larger, 10cm 2 Or larger, 16cm 2 (or larger). The thickness of each refractive element along the optical axis is 10 mm or less. (e.g., 6 mm or less, 4 mm or less, 3 mm or less, 2 mm or less, 1 mm or less).

[0014] Each optical element may include a pair of refractive elements, each of which has a cubic profile with an axial orientation along the radial direction of the optical element, and the actuator of the corresponding optical element is arranged to slide the pair of refractive elements in opposite directions orthogonal to the optical axis.

[0015] In a second aspect, a head-mounted display system is disclosed herein, comprising: a first optical element having a variable spherical refractive power (SPH); a second optical element having a variable SPH, a variable cylindrical refractive power (CYL), and a variable cylindrical axis (Axis); a see-through display disposed between the first and second optical elements; and an electronic controller communicating with the first optical element, the second optical element, and the see-through display, the electronic controller being programmed to adjust the SPH of the first optical element and the SPH, CYL, and Axis of the second optical element according to a prescription (Rx) of an individual user of the head-mounted display.

[0016] The head-mounted display may further include a frame for mounting the first optical element, the second optical element, and the fluoroscopic display relative to each other and, during use, relative to the user of the head-mounted display. During use of the head-mounted display, the second optical element may be positioned between the fluoroscopic display and the user. The first optical element may include two variable cylindrical lenses whose respective cylindrical axes are orthogonal to each other. The head-mounted display may further include an eye-tracking module, and an electronic controller is programmed to change the prescription of the second optical element based on information from the eye-tracking module regarding the location the user of the head-mounted display may be looking at. The electronic controller may be programmed to change the SPH, CYL, and Axis of the second optical element from a myopia prescription to a hyperopia prescription based on the location the user may be looking at. The head-mounted display may further include a biometric module, and the electronic controller is programmed to identify the user based on information from the biometric module and adjust the prescription of the second optical element based on the user's identity. This biometric module may be an iris recognition module.

[0017] Among other advantages, adjustable eyepieces can correct for a user's unique optical prescription, including astigmatism, while minimizing power consumption and electromechanical overhead. Adjustable eyepieces reduce the need to manufacture custom-made rigid eyepieces for each user and increase the usability of mixed reality products for users with non-emmetropic vision. The included biometric module can identify the user based on their unique iris pattern and adjust the adjustable eyepieces to accommodate prescriptions from multiple users on-site.

[0018] Other advantages will be apparent from the description, drawings and claims. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a wearable head-mounted viewer display.

[0020] Figure 2 This is a schematic diagram showing the eye placed behind an adjustable eyepiece with adjustable near and far optical elements.

[0021] Figure 3A This is a schematic diagram of a compound lens, which includes spherical and cylindrical lenses, used to correct anomalous vision.

[0022] Figure 3B This is a schematic diagram of three cylindrical lenses representing alternative means of correcting anomalous visual acuity.

[0023] Figure 4A This is a schematic diagram depicting an edge view of an exemplary, inactive refractive element.

[0024] Figure 4B This is a schematic diagram depicting an edge view of an exemplary refractive element combined with an actuator that is aligned with a washer.

[0025] Figure 5A This is a perspective view of the three components of the refractive element in a planar configuration.

[0026] Figure 5B yes Figure 5A The image shows a perspective view of a refractive element assembly actuated to provide a positive cylindrical refractive force.

[0027] Figure 5C yes Figure 5A The image shows a perspective view of a refractive element assembly actuated to provide negative cylindrical refractive force.

[0028] Figure 6 This is a schematic diagram of six pairs of refractive elements with a mirrored cubic profile in a sliding configuration.

[0029] In the diagram, similar symbols represent similar components. Detailed Implementation

[0030] Figure 1 An example head-mounted display system 60 is shown, comprising a see-through display 70 and various mechanical and electronic modules and systems supporting the operation of the display 70. The display 70 is housed in a frame 80, which can be worn by a user 90 of the display system and is configured to position the display 70 in front of the user 90's eyes. In some embodiments, the display 70 may be considered as eyeglasses. In some embodiments, a speaker 100 is coupled to the frame 80 and positioned near the user 90's ear canal. The display system may also include one or more microphones 110 for detecting sound. The microphones 110 may allow the user to provide input or commands to the system 60 (e.g., selecting a voice menu command, asking a natural language question, etc.), and / or may allow audio communication with other people (e.g., with other users of similar display systems). The microphones 110 may also collect audio data from the user's surroundings (e.g., sound from the user and / or environment). In some embodiments, the display system may also include peripheral sensors 120a, which may be separate from the frame 80 and attached to the user 90's body (e.g., on the head, torso, limbs, etc.). In some embodiments, the peripheral sensor 120a can acquire data characterizing the physiological state of the user 90.

[0031] In some embodiments, the display system may further include an eye-tracking module 125a. In some embodiments, the eye-tracking module 125a may include a biometric module to acquire biometric data of the user 90. In some embodiments, the biometric module may be an iris recognition module.

[0032] In some embodiments, eye-tracking module 120a can acquire fixed depth data. Eye-tracking module 120a can be operatively coupled to local processor and data module 140 via communication link 125b (e.g., wired or wireless connection). Eye-tracking module 120a can transmit biometric data and fixed depth data to local processor and data module 140.

[0033] Display 70 is operatively coupled to local data processing module 140 via communication link 130, such as via a wired cable or wireless connection. This local data processing module can be mounted in various configurations, such as being fixedly attached to frame 80, fixedly attached to a user's helmet or hat, embedded in headphones, or movably attached to user 90 (e.g., in a backpack configuration or a belt-coupled configuration). Similarly, sensor 120a can be operatively coupled to local processor and data module 140 via communication link 120b (e.g., via a wired cable or wireless connection). Local processing and data module 140 may include a hardware processor and digital memory, such as non-volatile memory (e.g., flash memory or hard disk drive), both of which can be used to assist in data processing, caching, and storage. Data may include 1) data captured from sensors (which may be operatively coupled to frame 80 or otherwise attached to user 90, such as image capture devices (e.g., cameras), microphones, inertial measurement units, accelerometers, compasses, GPS units, radios, gyroscopes, and / or other sensors disclosed herein); and / or 2) data obtained and / or processed using remote processing module 150 and / or remote data repository 160 (including data relating to virtual content), which may be transmitted to display 70 after such processing or retrieval. Local processing and data module 140 may be operatively coupled to remote processing module 150 and remote data repository 160 via communication links 170, 180, such as wired or wireless communication links, such that these remote modules 150, 160 are operatively coupled to each other and available as resources of local processing and data module 140. In some embodiments, local processing and data module 140 may include one or more of image capture devices, microphones, inertial measurement units, accelerometers, compasses, GPS units, radios, and / or gyroscopes. In some other embodiments, one or more of these sensors may be attached to the frame 80, or may be a separate device that communicates with the local processing and data module 140 via wired or wireless communication.

[0034] Remote processing module 150 may include one or more processors to analyze and process data, such as image and audio information. In some embodiments, remote data repository 160 may be a digital data storage facility that is available via an internet or other network configuration in a “cloud” resource setup. In some embodiments, remote data repository 160 may include one or more remote servers that provide information (e.g., information for generating augmented reality content) to local processing and data module 140 and / or remote processing module 150. In other embodiments, all data is stored in the local processing and data module, and all computations are performed within the local processing and data module, thereby allowing for fully autonomous use from the remote module.

[0035] A variable eyepiece assembly, included in the display's eyepiece, adjusts the eyepiece's refractive power to match the user's fixed depth of vision. The refractive power of the variable assembly can be set to different values ​​within a possible range, performing the function of a fixed lens and increasing the flexibility of controlled correction. The user's optical prescription (Rx) for correcting refractive errors can be loaded into the head-mounted viewer's controller, and the variable assembly is modified to correct for its unique set of parameters. The head-mounted viewer can perform this modification for each new user, thereby sequentially correcting each unique Rx.

[0036] Reference Figure 2 The eyepiece 200 of the head-mounted display system directs light from the projector 220 to the user's eye 210. The projector 220 and eyepiece 200 are positioned relative to each other and the user's eye 210 via a frame or housing (not shown). The projector 220 is located next to the user's temple and directs light to an end of the eyepiece 200 that extends beyond the user's temple. As shown, the eyepiece 200 includes a planar waveguide 240, an input coupling grating (ICG) 230, and an output coupling element (OCE) 250; however, more complex arrangements (e.g., consisting of multiple stacked waveguides) are also possible. A first zoom assembly 270a is located on the world side of the waveguide 240, and a second zoom assembly 270b is located on the user side. In general, the refractive power of the zoom assemblies 270a and 270b is adjusted to simultaneously correct the optical characteristics of the eyepiece to account for the virtual image depth plane and the user's Rx.

[0037] ICG 230 is positioned to receive light from projector 220 and facilitate the coupling of light from projector 220 into the surface grating within eyepiece 200. ICG 230 is located at or near the edge of eyepiece 200 closest to projector 220. ICG 230 guides the light from projector 220 into a guiding mode in the planar waveguide substrate 240 of eyepiece 200.

[0038] Planar waveguide substrate 240 guides coupled light along eyepiece 200 to coupling element (OCE) 250 via total internal reflection at its surface. OCE 250 is a second surface grating configured to extract light from planar waveguide substrate 240 and redirect it to user's eye 210. OCE 250 may include an outgoing pupil expander (EPE) or an orthogonal pupil expander (OPE) or both. OCE 250 is located in front of user's eye 210, so that light from the projector is delivered to the user's pupil 212, which can be positioned to receive light output from OCE 250. This area is referred to as the eye box. OCE 250 may further have a lateral dimension to accommodate a range of lateral positions of the eye box. For example, a non-limiting range of the lateral dimension 251 of OCE 250 may be 30 mm or less (e.g., 25 mm or less, 20 mm or less, 15 mm or less).

[0039] A zoom assembly 270b, disposed on the user-facing surface of eyepiece 200, corrects the user's non-orthographic vision, including astigmatism. The zoom assembly 270b also positions the focus of eyepiece 200 on the correct depth plane to display the virtual image. This focus placement also affects the focus of the real image transmitted to the user via the display. A zoom assembly 270a, disposed on the world-facing surface of eyepiece 200, corrects the focus placement of the real image resulting from the correction by the zoom assembly 270b. The zoom assembly 270a includes two optical elements, 271a and 271b, while the zoom assembly 270b includes three optical elements, 271c, 271d, and 271e.

[0040] In some embodiments, each optical element 271a-e includes a refractive element comprising a deformable optical material in contact with a deformable film. The refractive element is coupled to actuators 272a-e, which operate to alter the refractive power of the connected optical elements 271a-e, as further described in FIG. 4. For example, actuator 272 may deform at least one surface of a corresponding refractive element along a single axis, thereby causing the refractive element of optical element 271 to perform the function of a variable cylindrical lens. In some embodiments, the actuator may be a piezoelectric actuator.

[0041] Actuators 272a-e apply force in response to control signals from controller 274. In some embodiments, head-mounted viewer controller 274 performs calculations to determine the refractive power of each optical element 271a-e. The lens profiles of each optical element 271a-e are combined to determine the refractive power of zoom assembly 270a or 270b. The refractive power of the zoom assembly can vary based on various considerations, including user Rx, user environment, projected image, and / or combinations of these parameters.

[0042] In some embodiments, the controller 274 may receive biometric data from the eye-tracking module and adjust the refractive power of the zoom component 270b to correct the user's Rx based on the user's biometrics. In some embodiments, the controller 274 may receive the user's fixed depth data from the eye-tracking module and adjust the refractive power of the zoom component 270b to correct the user's myopia or hyperopia Rx. Similarly, the controller 274 may receive the user's fixed depth data from the eye-tracking module and adjust the lens profile of the zoom optics 270a to adjust the optical depth of the virtual image to match the user's fixed depth.

[0043] Typically, the human eye may have refractive errors that result in conditions such as myopia, hyperopia, astigmatism, or a combination thereof. These refractive errors are corrected using corrective lenses that alter the direction of incident light. Myopia or hyperopia occurs when the projected image of the eye is out of focus from the plane behind the eye and is usually corrected by lenses with a 'spherical' profile positioned between the eye and the incident light. Broadly speaking, a plano-spherical lens profile can be considered a planar section of the surface of a sphere, resulting in a lens profile with two opposing surfaces: a curved surface and a planar surface. The curved surface of a spherical lens is radially symmetrical about a central axis orthogonal to the planar surface. Lenses with a spherical profile arranged along the optical axis of the user's eye correct these refractive errors.

[0044] Astigmatic refractive errors are caused by the varying curvature of the eye's lens along different directions. Lenses with a 'cylindrical' profile can correct this type of error. A planar-cylindrical lens profile can be considered as a planar section of a cylinder taken parallel to its longitudinal axis. This results in the lens having both curved and flat surfaces (e.g., convex surfaces). The longitudinal axis along the center of the planar surface is called the cylindrical axis. The curved surfaces have equal radii of curvature along the length of the cylindrical profile.

[0045] Typically, lenses with spherical and cylindrical portions are used to correct refractive errors in astigmatic aemesis. The ophthalmic prescription (Rx) combines the spherical, cylindrical, and cylindrical axis portions (SPH, CYL, Axis), representing the refractive power of the spherical and cylindrical lenses, respectively, and the orientation of the cylindrical axis. The cylindrical axis is defined using a Cartesian coordinate system orthogonal to the optical axis with a horizontal orientation of 0°.

[0046] Spherical or cylindrical lenses each have their own intensity, or refractive power, usually measured in diopter (D). The refractive power of a lens can be zero, negative (e.g., diverging), or positive (e.g., converging). Without being bound by theory, the refractive power can be equal to the reciprocal of the focal length (f), D = 1 / f. For example, a lens with a refractive power of +3D will bring parallel rays from optical infinity to focus at 1 / 3 of a meter. As a further example, a flat or planar lens has a refractive power of 0D and will not converge or diverge light.

[0047] Rx can be represented by a combination of spherical and cylindrical lenses, such as... Figure 3A As shown. The figure depicts an exemplary assembly of a spherical lens 310 with a refractive power of S and a cylindrical lens 312 with a refractive power of C. The cylindrical axis 313 of the cylindrical lens 312 is shown oriented at an angle A relative to the horizontal plane. Without being bound by theory, any R... x The phase distribution of a point (x,y) on the surface and R x (x,y)∝S(x 2 +y 2 )+C(cosAx+sinAy) 2 They are directly proportional, where S is the refractive power of the spherical lens, C is the refractive power of the cylindrical lens, and A is the angular orientation of the cylindrical lens.

[0048] The corrective capability of the spherical lens 310 can alternatively be achieved by a pair of cylindrical lenses 312, whose cylindrical axes are oriented at 90° to each other. Therefore, Figure 3A The combination of spherical lens 310 and cylindrical lens 312 shown can also be achieved by combining three cylindrical lenses. Figure 3B The arrangement of three cylindrical lenses 312a, 312b, and 312c is depicted, with their cylindrical axes arranged radially at 30°, 90°, and 150° from the horizontal plane of the eye, respectively, and each having a refractive power of C. 30 C 90 and C 150 Without being bound by theory, for each corresponding lens, the R-axis with spherical and cylindrical portions is corrected. x Required refractive power C 30 C 90 and C 150 It can be determined by the following formula

[0049]

[0050]

[0051]

[0052] Based on the above, Figure 2The optical elements 271a-e depicted can perform the function of cylindrical lenses, and they can be oriented and combined in the optical elements to achieve the desired Rx.

[0053] While arrangements of cylindrical axes in radial directions at 30°, 90°, and 150° have been described and will work for any three-element Rx (such as SPH, CYL, Axis), these orientations are not the only solution for correcting astigmatic anomalous vision. Typically, many sets of angles will provide sufficient degrees of freedom to match the three parameters of Rx. For example, three cylindrical axes oriented at 0°, 60°, and 120° (e.g., from the eye's horizontal plane) can also correct such Rx. This arrangement maintains... Figure 3B The image depicts a 60° separation between the cylindrical axes. However, as a further example, three cylindrical lenses with cylindrical axes spaced at 45° intervals (e.g., 0°, 45°, 90°) can also provide the required correction for the three-element Rx.

[0054] Typically, the total angular separation between the three cylindrical axes of a set of cylindrical lenses is sufficient to eliminate redundancy between two or more cylindrical lenses. For example, the total angular separation between the three cylindrical axes can range from 45° to 180°. The angular displacement of the middle cylindrical axis from the other two cylindrical axes can be approximately equal (e.g., for a total angular separation of 90°, the middle axis can be 45° away from the other two axes), or the cylindrical axes can be separated by unequal angles.

[0055] Generally, various optical elements that can provide variable cylindrical lenses can be used for Figure 2 The variable zoom component is depicted in the image. Figure 4A and 4B An example is shown, illustrating an optical element 400 comprising a deformable transparent film 410, a transparent substrate 412, a deformable optical material 414, and a gasket 416 surrounding the edge of the deformable optical material 414. The deformable transparent film 410, the deformable optical material 414, and the substrate 412 together constitute a variable cylindrical lens, wherein the optical axis 420 is orthogonal to a cylindrical axis extending perpendicular to the plane shown in the figure. The thickness of the optical element 400 is 10 mm or less (e.g., 6 mm or less, 4 mm or less, 3 mm or less, 2 mm or less, 1 mm or less). A relatively thin optical element may be desirable, providing a compact and lightweight device suitable for incorporation into a head-mounted display.

[0056] The optical element 400 also includes an actuator 472, which is arranged to change the cylindrical refractive force of the optical element.

[0057] A deformable transparent film 410 is positioned to contact the upper edge of a rigid washer 416 and the upper surface of an optical material 414. A contact element of an actuator 472 is positioned to contact the opposite side of the film 410. The transparent film 410 comprises a transparent material capable of deforming (e.g., bending) when a suitable force is applied. Example materials include inorganic glasses, such as borosilicate glass, or plastic films, such as thin-film polycarbonate. The thickness of the transparent film 410 is sufficient to provide protection for the optical material 416 while still maintaining flexibility. For example, the thickness of the transparent film may be approximately 0.1 mm or less.

[0058] A washer 416 surrounds the edge and encloses the optical material 414 to a common height. When the optical element 271 is actuated, the washer 416 accommodates the lateral expansion and contraction of the material 414. The washer 416 further partially encloses the transparent substrate 412 to form an aperture through which light passes along the optical axis 420. In some embodiments, this aperture may be 1 cm. 2 Or a larger observation area (e.g., 5 cm) 2 Or larger, 10cm 2 Or larger, 16cm 2 (or larger).

[0059] Arranged between the substrate 412 and the film 410 is a deformable optical material 414. The optical material 414 comprises a low-hardness material that is substantially transparent to light at optical wavelengths. In some embodiments, the optical material may be a solid optical material, such as an elastic material. For example, materials such as silicone rubber or gel may be used for the optical material 414. Other materials measured on a 000-scale Shore hardness tester between 10 and 50 (e.g., between 10 and 40, between 10 and 30, between 10 and 20, between 20 and 50, between 30 and 50, or between 40 and 50) may also be considered.

[0060] A rigid transparent substrate 412 provides a rigid base for the deformable optical material 414 and extends across the entire internal width of the rigid gasket 416. The rigid transparent substrate 412 comprises a material that maintains its shape under forces applied by the deformable optical material 414 and is substantially transparent to light at optical wavelengths. For example, the substrate 412 may be formed of plastic or inorganic glass. The thickness of the substrate 412 may be 1 mm or less (e.g., 0.8 mm or less, 0.6 mm or less, 0.4 mm or less, 0.2 mm or less).

[0061] exist Figure 4A In the diagram, optical element 400 is shown in an inactive state, wherein deformable film 410 has an infinite radius of curvature, for example, a refractive force of 0. When activated by actuator 472, deformation of film 410 causes optical material 414 to compress or expand, thereby changing the refractive force of optical element.

[0062] Now for reference Figure 4B The actuator 272 mechanism is shown as being registered with a rigid washer 416 and contacting the outer edge of the membrane 410 of the refractive element 400. The actuator 272 pivots on the washer 416 to apply parallel and co-directional forces, thereby deforming the membrane 410 along an axis parallel to the edge of the washer 416 and relative to the center of the edge of the washer 416. The deformation changes the radius of curvature of the membrane 410, causing it to bend. The actuator 272 causes the membrane 410 to be concave or convex, respectively, associated with positive or negative refractive forces. The axis around which the deformation occurs is the cylindrical axis of the optical element. Figure 4B In the example, the axis extends out of the plane perpendicular to the page.

[0063] Figures 5A to 5C The illustrations of these variations are shown in the figure. Figure 5A Depicting and Figure 4A and 4B The similar refractive element 500 depicted only shows the transparent film 510, the rigid substrate 512, and the optical material 514. Figure 5A The left side shows a Cartesian coordinate system 530 for reference. The optical axis of the refractive element 500 is parallel to the Z-axis of the coordinate system 530. A change in the radius of curvature of the film 510 relative to the cylindrical axis 520 orthogonal to the optical axis causes compression or expansion of the optical material 514, resulting in a change in the refractive power of the refractive element 500. The change in the radius of curvature of the film 510 results in a positive or negative cylindrical refractive power. For example, the cylindrical refractive power can be varied in the range from -5D to +5D (e.g., -4D, -3D, -2D, -1D, 0D, 1D, 2D, 3D, or 4D). For example, the cylindrical refractive power can be varied from -5D to +5D in increments of 0.1D or greater (e.g., 0.2D or greater, such as 0.25D or 0.5D).

[0064] Although Figure 5A The refractive element 500 is depicted in an inactive state, but Figure 5B and 5C The refractive element 500 is depicted in an activated state. Figure 5B A refractive element 500 actuated along the cylindrical axis 520 is shown, thereby creating a convex planar-cylindrical lens. Figure 5B The lens provides positive cylindrical refractive power (e.g., 1D, 2D, 3D, or 4D). Figure 5C The same exemplary refractive element 500 is shown, which is actuated to form a concave planar-cylindrical lens, thereby providing a negative cylindrical refractive force (e.g., -4D, -3D, -2D, or -1D).

[0065] Other components that can function as variable cylindrical lenses are also possible. For example, in another embodiment, the variable focus assembly comprises a sliding pair of rigid refractive elements (e.g., molded or ground elements made of glass or plastic), each pair of which functions as a variable cylindrical lens. Figure 6 An example is shown depicting a variable focus assembly 600 comprising three pairs of refractive elements 620, 621, and 622. Specifically, pair 620 includes refractive elements 620a and 620b, pair 621 includes refractive elements 621a and 621b, and pair 622 includes refractive elements 622a and 622b. Nested perspective axes are shown to... Figure 6 The x-axis, y-axis, and z-axis orientation.

[0066] Each refractive element (620a, b; 621a, b; and 622a, b) has a planar and opposing two-dimensional cubic surface. Typically, a cubic surface is defined by a three-dimensional polynomial equation, such as a cubic polynomial. A refractive element with a cubic surface can be constructed by combining positive and negative cylindrical lens profiles with similar radii of curvature. The resulting surface closely follows a cubic polynomial. The cubic surface of one refractive element in a pair faces the cubic surface of the second refractive element in the pair, which is a mirror image of the first refractive element. A pair of refractive elements with aligned cubic vertices functions as a lens with zero refractive power. When the cubic vertices of the lens are translated and misaligned, the refractive element refracts the passing light rays onto the focal line, thus performing the effect of a variable cylindrical lens.

[0067] Each pair of refractive elements, such as refractive elements 620a and 620b, is spaced apart by a distance that allows the refractive elements to translate relative to each other without the three surfaces contacting. Figure 6 In the exemplary embodiments, refractive elements 620a and 620b are capable of translating a certain distance along the X-axis without the cubic surfaces contacting each other. This distance depends on the depth of the cubic profile of the paired refractive elements. Refractive elements 620a and 620b, 621a and 621b, and 622a and 622b typically comprise rigid transparent materials, such as inorganic glass (e.g., borosilicate glass) or suitable plastics (e.g., polycarbonate).

[0068] Using optical element 620 as a representative example, the total thickness of optical element 620 can be 10 mm or less, as described above, and includes the respective thicknesses of refractive elements 620a and 620 and their separation distance. The cubic profiles of refractive elements 620a and 620b are oriented along a common radial axis orthogonal to the optical axis (equivalent to the cylindrical axis described above). In this way, optical element 620 can perform the function of a variable cylindrical lens. Optical element 620 is shown in contact with linear actuator 630. Actuator 630 operates to translate refractive elements 620a and 620b in opposite directions along a common axis orthogonal to the optical axis.

[0069] For example, the linear actuator 630 can translate the refractive element 620b relative to 620a to produce positive or negative refractive forces. Displacement of the mirror cubic profile of the refractive element in one direction will result in a positive refractive force (e.g., 1D, 2D, 3D, 4D, or 5D). Displacement of the mirror cubic profile of the refractive element in the opposite direction will result in a negative cylindrical refractive force (e.g., -1D, -2D, -3D, -4D, or -5D).

[0070] The three optical elements 620, 621, and 622 are shown having cylindrical axes corresponding to 150°, 90°, and 30° from the horizontal plane of the eye, similar to Figure 3B The lens. In different ways, the cylindrical axis is oriented at 150°, 90°, and 30° from the x-axis in the xy-plane, respectively. The dashed lines on the cubic surfaces of refractive elements 620b, 621b, and 622b are aligned with the respective cylindrical axes of optical elements 620, 621, and 622. Each optical element 620, 621, and 622 is shown as being in contact with linear actuators 630, 631, and 632. As described above, any three refractive elements having their respective cubic profiles corresponding to 150°, 90°, and 30° from the horizontal plane of the eye, such as... Figure 6 An exemplary system can perform corrections to any user's ophthalmic prescription. Similarly, any two such optical elements having cubic vertices oriented at right angles will perform the function of a spherical lens. For example, such an arrangement can be used to perform virtual image plane adjustment of the zoom assembly 270a.

[0071] Some embodiments have been described. Other embodiments are described in the following claims.

Claims

1. A head-mounted display system, comprising: A waveguide configured to output light to a user's eye, the waveguide having a user side and a world side; A first zoom component located on the user side, the first zoom component comprising: A first optical element, comprising a first refractive element arranged along an optical axis and a first actuator arranged to change a first cylindrical refractive force of the first refractive element in response to a first control signal, the first refractive element having a first cylindrical axis associated with the first refractive element along a first radial direction orthogonal to the optical axis; A second optical element, comprising a second refractive element arranged along the optical axis, and a second actuator arranged to change the second cylindrical refractive force of the second refractive element in response to a second control signal, the second refractive element having a second cylindrical axis associated with the second refractive element along a second radial direction orthogonal to the optical axis; A third optical element, comprising a third refractive element arranged along the optical axis, and a third actuator arranged to change the third cylindrical refractive force of the third refractive element in response to a third control signal along a third radial direction orthogonal to the optical axis, wherein the first radial direction, the second radial direction, and the third radial direction are different. A second zoom assembly located on the world side, the second zoom assembly comprising: A fourth optical element, comprising a fourth refractive element arranged along an optical axis, and a fourth actuator arranged to change a fourth cylindrical refractive force of the fourth refractive element in response to a fourth control signal, the fourth refractive element having a fourth cylindrical axis associated with the fourth refractive element along a fourth radial direction orthogonal to the optical axis; and A fifth optical element, comprising a fifth refractive element arranged along the optical axis, and a fifth actuator arranged to change the fifth cylindrical refractive force of the fifth refractive element in response to a fifth control signal; the fifth refractive element having a fifth cylindrical axis associated with the fifth refractive element along a fifth radial direction orthogonal to the optical axis; and An electronic controller communicating with the first actuator, the second actuator, and the third actuator, the electronic controller being configured to provide the first control signal, the second control signal, and the third control signal respectively to the first actuator, the second actuator, and the third actuator during operation, such that the first refractive element, the second refractive element, and the third refractive element together form an optical element having an overall spherical refractive force, a cylindrical refractive force, and a cylindrical axis according to a prescription.

2. The head-mounted display system according to claim 1, wherein, The angular separation between the first radial direction and the second radial direction is equal to the angular separation between the second radial direction and the third radial direction.

3. The head-mounted display system according to claim 1 or claim 2, wherein, For a Cartesian coordinate system orthogonal to the optical axis, the first radial direction is 30°, the second radial direction is 90°, and the third radial direction is 150°.

4. The head-mounted display system according to claim 3, wherein, The first cylindrical refractive force The second cylindrical refractive force and the refractive force of the third cylinder The values ​​of S, C, and A are related according to the following formula: ， Where S is the refractive power of the spherical lens, C is the refractive power of the cylindrical lens, and A is the angular orientation of the cylindrical lens.

5. The head-mounted display system according to claim 1 or 2, wherein, At least one of the refractive elements comprises a deformable optical material.

6. The head-mounted display system according to claim 5, wherein, The deformable optical material is a solid optical material.

7. The head-mounted display system according to claim 6, wherein, The solid optical material is an elastic material.

8. The head-mounted display system according to claim 7, wherein, The elastic material is silicone rubber.

9. The head-mounted display system according to claim 5, wherein, At least one of the refractive elements includes a deformable transparent film adjacent to the deformable optical material, and the actuator of the at least one refractive element is arranged to deform the shape of the deformable transparent film to change the cylindrical refractive force of the at least one refractive element.

10. The head-mounted display system according to claim 9, wherein, The actuator causes the deformable transparent film to bend around the cylindrical axis of the at least one refractive element to change the cylindrical refractive force of the at least one refractive element.

11. The head-mounted display system according to claim 9, wherein, At least one of the refractive elements includes a rigid transparent substrate adjacent to the deformable optical material and located on the side of the refractive element opposite to the deformable optical material.

12. The head-mounted display system according to any one of claims 9-11, wherein, The optical element of at least one of the refractive elements includes a rigid washer located at the edge of the deformable optical material, and the deformable transparent film pivots on the rigid washer when acted upon by the actuator.

13. The head-mounted display system according to claim 1 or 2, wherein, The cylindrical refractive power of each of the first, second, and third optical elements is variable in the range from -5D to +5D.

14. The head-mounted display system according to claim 1 or 2, wherein, The optical element has an area of ​​1 cm². 2 Or a larger hole.

15. The head-mounted display system according to claim 1 or 2, wherein, The thickness of each refractive element along the optical axis is 10 mm or less.

16. The head-mounted display system according to claim 1 or 2, wherein, Each optical element includes a pair of refractive elements, each of the pair having a cubic profile with an axial orientation along the radial direction of the optical element, and an actuator for the corresponding optical element is arranged to slide the pair of refractive elements in opposite directions orthogonal to the optical axis.

17. A head-mounted display, comprising: A first component having variable spherical refractive power, the first component comprising: A first variable cylindrical lens, the first variable cylindrical lens having a first cylindrical axis along a first radial direction orthogonal to the optical axis associated with the first variable cylindrical lens; A second variable cylindrical lens, the second variable cylindrical lens having a second cylindrical axis associated with the second variable cylindrical lens along a second radial direction orthogonal to the optical axis and the first radial direction; A second component having variable spherical refractive force, variable cylindrical refractive force, and variable cylindrical axis, the second component comprising: A third variable cylindrical lens, the third variable cylindrical lens having a third cylindrical axis associated with the third variable cylindrical lens along a third radial direction orthogonal to the optical axis; A fourth variable cylindrical lens, the fourth variable cylindrical lens having a fourth cylindrical axis associated with the fourth variable cylindrical lens along a fourth radial direction orthogonal to the optical axis; A fifth variable cylindrical lens having a fifth cylindrical axis associated with the fifth variable cylindrical lens along a fifth radial direction orthogonal to the optical axis, wherein the third radial direction, the fourth radial direction, and the fifth radial direction are different; A perspective display disposed between the first component and the second component; and An electronic controller communicating with the first component, the second component, and the perspective display, the electronic controller being programmed to adjust the variable spherical refractive power of the first component and the variable spherical refractive power, the variable cylindrical refractive power, and the variable cylindrical axis of the second component according to a prescription from an individual user of the head-mounted display.

18. The head-mounted display of claim 17, further comprising a frame for mounting the first component, the second component, and the perspective display relative to each other, and for mounting relative to a user of the head-mounted display during use.

19. The head-mounted display according to claim 17 or claim 18, wherein, The second component is positioned between the perspective display and the user during use of the head-mounted display.

20. The head-mounted display of claim 17 or 18, further comprising an eye-tracking module, wherein the electronic controller is programmed to change the prescription of the second component based on information from the eye-tracking module regarding the location being looked at by the user of the head-mounted display.

21. The head-mounted display according to claim 20, wherein, The electronic controller is programmed to change the variable spherical refractive power, the variable cylindrical refractive power, and the variable cylindrical axis of the second component from a myopia prescription to a hyperopia prescription, depending on the position the user is looking at.

22. The head-mounted display of claim 17 or 18, further comprising a biometric module, wherein the electronic controller is programmed to identify a user based on information from the biometric module and adjust the prescription of the second component based on the user's identity.

23. The head-mounted display according to claim 22, wherein, The biometric module is an iris recognition module.

Images