Optical systems for vision correction in near-eye displays

Abstract

Aspects of this disclosure provide an optical system. The optical system includes a first lens, a second lens, and a vision correction adapter. The first lens includes a first light-transmitting member having a first surface and a second surface. The second lens includes a second light-transmitting member having a third surface and a fourth surface. The vision correction adapter is positioned between the first lens and the second lens. The first lens and the second lens are spaced apart by the thickness of the vision correction adapter, the thickness of which is selected to correct either myopia or hyperopia. The central region of the vision correction adapter includes an opening.

Description

[Technical Field]

[0001] Reference This application claims priority to U.S. Patent Application No. 18 / 201,633, "VISION CORRECTION FOR NEAR EYE DISPLAY," filed on 24 May 2023, which is incorporated herein by reference in its entirety.

[0002] This disclosure relates to near-eye display technology. [Background technology]

[0003] The background art provided herein is intended to provide a general context for this disclosure. To the extent described herein in relation to the background art, the inventions made by the inventors named in this application, and any other descriptions that do not qualify as prior art at the time of filing, are not explicitly or implicitly acknowledged as prior art to this disclosure.

[0004] Near-eye displays (NEDs) are being developed to provide improved user experiences in fields such as augmented reality (AR) and virtual reality (VR). NEDs can include a variety of wearable devices, such as head-mounted displays (HMDs) and smart glasses. For example, an HMD includes a relatively small display device and an optical system that can generate a virtual image within the field of view of one or both eyes. To the eye, the virtual image appears distant and much larger than the relatively small display device. [Overview of the Initiative] [Means for solving the problem]

[0005] Aspects of this disclosure provide an optical system. The optical system includes a first lens, a second lens, and a vision correction adapter. The first lens includes a first light-transmitting member having a first surface and a second surface. The second lens includes a second light-transmitting member having a third surface and a fourth surface. The vision correction adapter is positioned between the first lens and the second lens. The first lens and the second lens are spaced apart by the thickness of the vision correction adapter, the thickness of which is selected to correct either myopia or hyperopia. The central region of the vision correction adapter includes an opening. The first lens may be flexible.

[0006] In one embodiment, the vision correction adapter is a band between two parallel surfaces.

[0007] In one example, the thickness of the vision correction adapter is thinner than the threshold thickness required to correct nearsightedness, and the thickness of the vision correction adapter is thicker than the threshold thickness required to correct farsightedness.

[0008] In one example, the optical system includes a reflective polarizer positioned on one of the first and second surfaces, and a beam splitter positioned on one of the third and fourth surfaces. The beam splitter is configured to partially transmit and partially reflect light incident on it. The reflective polarizer is configured to allow light having a first linear polarization state to pass through and to reflect light having a second linear polarization state perpendicular to the first linear polarization state. An optical cavity of at least one of the first and second lenses is formed between the reflective polarizer and the beam splitter. The optical system is configured to direct light from a display device to a viewing area, and the path of light from the display device passes through the optical cavity multiple times.

[0009] Aspects of this disclosure provide an optical system comprising a first flexible lens and a vision correction adapter. The shape of the vision correction adapter is based on the degree and direction of astigmatism, and the vision correction adapter is configured to change the shape of the first lens to match the shape of the vision correction adapter in order to correct the astigmatism.

[0010] In one example, the central region of the vision correction adapter includes an opening, the vision correction adapter includes a band and a curved surface, the shape of which is based on the degree and direction of astigmatism, and the curved surface is configured to modify the shape of the first lens to match the shape of the curved surface.

[0011] In one example, the vision correction adapter includes discrete point contacts arranged on a curved surface, the shape of which is determined based on the degree and direction of astigmatism, and the discrete point contacts arranged on the curved surface are configured to modify the shape of the first lens to match the shape of the curved surface.

[0012] Aspects of the present disclosure provide an optical system. The optical system includes a first flexible lens and a vision correction adapter. The first lens includes a first light-transmitting member having a first surface and a second surface. The central region of the vision correction adapter includes an opening, and the inclined surface of the vision correction adapter is inclined with respect to the optical axis of the optical system, and the inclination angle and orientation of the inclined surface of the vision correction adapter is based on diplopia, and the vision correction adapter is configured to incline the first lens according to the inclination angle and orientation of the inclined surface of the vision correction adapter in order to correct diplopia.

[0013] In one example, a vision correction adapter includes a band and a beveled surface.

[0014] In one example, the optical system includes a second lens containing a second light-transmitting member having a third and a fourth surface, a reflective polarizer, and a beam splitter. The reflective polarizer is located on one of the first and second surfaces and is configured to allow light having a first linearly polarized state to pass through and to reflect light having a second linearly polarized state perpendicular to the first linearly polarized state. The beam splitter is located on one of the third and fourth surfaces and is configured to partially transmit and partially reflect light incident on the beam splitter. An optical cavity in at least one of the first and second lenses is formed between the reflective polarizer and the beam splitter. The optical system is configured to direct light from a display device towards a viewing area, and the path of light from the display device passes through the optical cavity multiple times.

[0015] Aspects of the present disclosure provide an optical system. The optical system includes a first lens comprising a first light-transmitting member having a first surface and a second surface, a second lens comprising a second light-transmitting member having a third surface and a fourth surface, and a vision correction adapter. At least one of the first lens or the second lens is flexible, the central region of the vision correction adapter includes an opening, and the vision correction adapter is configured to perform a plurality of the following: (i) changing the distance between the first lens and the second lens to correct one of myopia and hyperopia, (ii) changing the shape of at least one of the first lens or the second lens to match the shape of the vision correction adapter to correct astigmatism, and (iii) tilting at least one of the first lens or the second lens according to the shape of the vision correction adapter to correct diplopia.

[0016] In one example, a vision correction adapter is configured to change the distance between a first lens and a second lens to correct either myopia or hyperopia. The thickness of the vision correction adapter is based on the degree of either myopia or hyperopia. The vision correction adapter includes a band and a curved surface, and is configured to perform at least one of the following: (i) to correct astigmatism, by changing the shape of at least one of the first lens or the shape of the second lens to match the shape of the vision correction adapter; and (ii) to correct diplopia, by tilting at least one of the first lens or the second lens according to the shape of the vision correction adapter.

[0017] In one example, the vision correction adapter is configured to modify the shape of at least one of the first or second lens to match the shape of the vision correction adapter in order to correct astigmatism, and the vision correction adapter is configured to tilt at least one of the first or second lens according to the shape of the vision correction adapter in order to correct diplopia.

[0018] In one example, the first and second lenses are flexible, the vision correction adapter includes a curved surface and a beveled surface, the shape of the curved surface is based on the degree and direction of astigmatism, the curved surface is configured to modify the shape of the first lens to match the shape of the curved surface in order to correct astigmatism, the beveled surface is inclined with respect to the optical axis of the optical system, the inclination angle and direction of the beveled surface is based on diplopia, and the vision correction adapter is configured to inclinate the second lens according to the inclination angle and direction of the beveled surface in order to correct diplopia.

[0019] In one example, the first lens is flexible, the vision correction adapter includes a curved surface, the shape of the curved surface is based on the degree and orientation of astigmatism, the curved surface is configured to change the shape of the first lens to conform to the shape of the curved surface to correct astigmatism, the curved surface is inclined with respect to the optical axis of the optical system, the inclination angle and orientation of the curved surface are based on diplopia, and the vision correction adapter is configured to tilt the first lens according to the inclination angle and orientation of the curved surface to correct diplopia.

[0020] Aspects of the present disclosure provide a method of manufacturing a vision correction adapter for an optical system. The method can include obtaining at least one vision correction information of myopia, hyperopia, astigmatism, or diplopia, and determining one or more of (i) the thickness of the vision correction adapter, or (ii) the shape of the vision correction adapter based on the vision correction information. The method can further include manufacturing the vision correction adapter based on the determined one or more of the thickness of the vision correction adapter or the shape of the vision correction adapter. The central region of the vision correction adapter may be hollow.

[0021] In one example, the manufactured vision correction adapter is configured to separate a first lens and a second lens in an optical system to correct at least one of myopia, hyperopia, astigmatism, or diplopia.

[0022] In one example, the thickness of the vision correction adapter is determined based on myopia or hyperopia, and the first lens and the second lens are separated by the thickness of the vision correction adapter to correct myopia or hyperopia.

[0023] In one example, the first lens is flexible. The shape of the vision correction adapter is determined based on the degree and orientation of astigmatism, and the manufactured vision correction adapter is arranged to change the shape of the first lens to conform to the shape of the vision correction adapter to correct astigmatism.

[0024] In one example, the shape of the vision correction adapter is determined based on diplopia, the shape of the vision correction adapter indicates the tilt angle and orientation of the inclined surface of the vision correction adapter, and the manufactured vision correction adapter is arranged to tilt the first lens according to the tilt angle and orientation of the inclined surface of the vision correction adapter to correct diplopia.

[0025] The following detailed description and the accompanying drawings will make the further features, properties and various effects of the disclosed protected subject matter more apparent.

Brief Description of the Drawings

[0026] [Figure 1] It is a diagram showing examples of eye rotation and head rotation. [Figure 2] It is a diagram showing the relationship between visual acuity and eccentricity. [Figure 3A] It is a diagram showing an example of myopia (or nearsightedness) and a vision correction method for correcting myopia. [Figure 3B] It is a diagram showing an example of myopia (or nearsightedness) and a vision correction method for correcting myopia. [Figure 3C] It is a diagram showing an example of hyperopia (or farsightedness) and a vision correction method for correcting hyperopia. [Figure 3D] It is a diagram showing an example of hyperopia (or farsightedness) and a vision correction method for correcting hyperopia. [Figure 3E] It is a diagram showing an example of astigmatism and a vision correction method for correcting astigmatism. [Figure 3F] It is a diagram showing an example of astigmatism and a vision correction method for correcting astigmatism. [Figure 3G] It is a diagram showing an exemplary prism used for correcting diplopia according to an embodiment of the present disclosure. [Figure 4A] It is a diagram showing an example of a vision correction adapter. [Figure 4B] It is a diagram showing an example of a vision correction adapter. [Figure 4C] It is a diagram showing an example of a vision correction adapter. [Figure 4D]This figure shows an example of a vision correction adapter. [Figure 4E] This figure shows an example of a vision correction adapter. [Figure 4F] This figure shows an example of a vision correction adapter. [Figure 4G] This figure shows an example of a vision correction adapter. [Figure 4H] This figure shows an example of a vision correction adapter. [Figure 5A] This is a side view showing a display system according to some embodiments of the present disclosure. [Figure 5B] This is a side view showing a display system according to some embodiments of the present disclosure. [Figure 5C] This is a side view showing a display system according to some embodiments of the present disclosure. [Figure 5D] This figure shows examples of vision correction for correcting nearsightedness and farsightedness. [Figure 6A] This figure shows an example of vision correction to correct astigmatism. [Figure 6B] This diagram shows an example of how to correct astigmatism. [Figure 7A] This figure shows some examples of display systems without double vision correction. [Figure 7B] This figure shows some examples of display systems with double vision correction. [Figure 8A] This figure shows an example of diplopia correction in a display system. [Figure 8B] This diagram shows examples of how to correct double vision. [Figure 9A] This figure shows an example of a flexible lens used in a display system according to an embodiment of the present disclosure. [Figure 9B] This figure shows an example of a flexible lens used in a display system according to an embodiment of the present disclosure. [Figure 10] This flowchart outlines a process (e.g., a vision correction process) according to some embodiments of the present disclosure. [Figure 11]This is a schematic diagram of a computer system according to one embodiment. [Modes for carrying out the invention]

[0027] A display system may include an optical system that directs a light beam from an object on the display device (e.g., an image displayed on the display device) or a real object to a photodetector. The optical system can form an image (e.g., a virtual image) on the image plane based on the light beam. In one embodiment, the photodetector is the user's eye. If the lens of the user's eye can form an image on the retina of the eye based on the virtual image on the image plane (or the directed light beam from the display device), the eye can see the object clearly and the eye has no visual impairment. Eye characteristics such as visual acuity (or clarity of vision) may vary considerably among users of the display system. If the display system is used by various users or users with varying or different eye conditions, such as various visual impairments (e.g., myopia (or nearsightedness), hyperopia (or farsightedness), astigmatism, and / or diplopia), the eye of a particular user with a visual impairment may form images in front of or behind the retina, and that particular user may not be able to see the object displayed on the display device or a real object clearly without vision correction, and the eye has a visual impairment.

[0028] Vision correction may be performed by the display system. The optical system may include at least one lens. The surface of at least one lens may be bent or curved so that the surface of at least one lens may have different shapes and refractive powers in two different axes (e.g., the X axis and the Y axis) in order to correct astigmatism. At least one lens may be tilted with respect to an axis (e.g., the optical axis of the optical system or an axis perpendicular to the optical axis) in order to correct diplopia. At least one lens may include a first lens and a second lens, and the distance between the first lens and the second lens may be adjusted to correct myopia or hyperopia.

[0029] According to one embodiment of the present disclosure, vision correction can be achieved by using a vision correction adapter (e.g., a prescription corrective lens adapter) in an optical system. At least one lens may include a first lens. The shape of the vision correction adapter may be based on astigmatism (e.g., the degree and direction of astigmatism), and the vision correction adapter may be configured to modify the shape of the first lens to match the shape of the vision correction adapter in order to correct astigmatism.

[0030] The inclined surface of the vision correction adapter may be inclined with respect to an axis (e.g., the optical axis of an optical system, or an axis perpendicular to the optical axis). The inclination angle and orientation of the inclined surface of the vision correction adapter may be based on diplopia (e.g., the degree and direction of diplopia), and the vision correction adapter may be positioned in contact with the first lens such that the first lens is inclined according to the inclination angle and orientation of the inclined surface of the vision correction adapter in order to correct diplopia.

[0031] At least one lens may include a first lens and a second lens. A vision correction adapter may be placed between the first lens and the second lens, and the first lens and the second lens may be spaced apart by the thickness of the vision correction adapter, the thickness of which may be selected to correct either myopia or hyperopia.

[0032] As described above, a vision correction adapter can be used to correct a single visual impairment. A vision correction adapter can also be used to correct multiple visual impairments. For example, the thickness and shape of the vision correction adapter separating the first and second lenses may be determined so that it can correct (i) myopia or hyperopia, (ii) astigmatism, and / or (iii) diplopia. The shape of the vision correction adapter may be determined based on astigmatism and / or diplopia.

[0033] In one example, the optical system and display device may be configured to be positioned within a user's eye distance threshold (e.g., 35 mm), and the display system may be called a near-eye display (NED) system. The display system is, for example, a head-mounted display (HMD) system worn by the user.

[0034] Considering human factors such as human vision (e.g., field of view (FOV), eye rotation) and head rotation can be helpful when designing the optical parameters of a display system. Optical designs with high resolution across the range of eye rotation can result in a more natural viewing experience for the user.

[0035] Unrestricted or unconscious eye rotation may be less than 20°. Figure 1 shows examples of eye and head rotation. Unconscious horizontal eye rotation may be less than the value to the left or right of the center (e.g., 20°), for example, 15°±2°. Conscious horizontal eye rotation can be greater than unconscious horizontal eye rotation. In one example, conscious horizontal eye rotation may be as high as 30°±2°. In another example, the eyes may rotate approximately 28°±8° upwards and 47°±8° downwards. Figure 1 also shows an example of natural head movement. In one example, natural head movement may be 45°±2° horizontally.

[0036] For example, a human's horizontal field of view, without eye movement, is slightly over 210°. The horizontal field of view (FOV) of both human eyes can be 210°. The vertical range of a human's field of view (or vertical FOV) is approximately 150°.

[0037] The human eye is not a perfect lens across the entire wide field of view (FOV). Visual acuity can indicate the clarity or sharpness of vision. Eccentricity can refer to the angular distance from the center of the field of view or from the fovea of ​​the retina. Figure 2 shows the relationship between visual acuity (including peripheral vision) and eccentricity. Visual acuity can decrease with this eccentricity. This means that the resolution of the optical system in the peripheral field of view may be lower than that of the optical system in the central field of view, as peripheral vision will be insufficient unless the eye is rotated to directly fixate on the peripheral field of view. By considering visual acuity, it is possible to avoid over-designing the optical system.

[0038] Visual acuity correction can be applied to correct various observer visual impairments. Figures 3A to 3G show examples of visual impairments and methods of visual acuity correction according to embodiments of the present disclosure. Visual impairments may include myopia (or nearsightedness), hyperopia (or farsightedness), astigmatism, diplopia (or double vision), and the like.

[0039] Figures 3A and 3B show an example of myopia (or nearsightedness) and a method of correcting vision to correct myopia. Referring to Figure 3A, myopia can refer to a condition in which the eye (60) can see near objects clearly, but not far objects (68). The lens (63) of the eye (60) may excessively focus nearly parallel rays from far objects (68), causing the rays to cross in front of the retina (68) and form an image (69) in front of the retina (68). More divergent rays from near objects may converge on the retina (65), forming a sharp image. The distance to the farthest object that can be seen clearly can be called the far point of the eye (60). The distance between the far object (68) and the eye (60) can be greater than the far point of the eye (60). The distance between a near object and the eye (60) can be less than the far point of the eye (60).

[0040] Referring to Figure 3B, in one example, myopia can be corrected by placing a divergent lens (or divergent spectacle lens) (70) in front of the eye (60). The divergent lens (70) and lens (63) can form an image (69') on the retina (65) from a distant object (68), and the eye (60) can see the distant object (68) clearly.

[0041] Figures 3C-3D show an example of hyperopia (or farsightedness) and a method of correcting vision to correct hyperopia. Referring to Figure 3C, hyperopia may refer to a condition where the eye (60) cannot see near objects (67) clearly, while the eye (60) can see distant objects clearly. The lens (63) of the eye (60) does not sufficiently focus the rays from near objects (67), so the rays cross over the retina (65), and therefore the image (66) is formed behind the retina (68). Rays with less divergence from distant objects can focus on the retina (65), forming a sharp image. The distance to the nearest object that can be seen clearly may be called the near point of the eye (60) (e.g., 25 cm). The distance between a distant object and the eye (60) may be greater than the near point of the eye (60). The distance between a near object (67) and the eye (60) may be less than the near point of the eye (60).

[0042] Referring to Figure 3D, in one example, hyperopia can be corrected by placing a converging lens (or converging spectacle lens) (71) in front of the eye (60). The converging lens (71) and lens (63) can form an image (66') on the retina (65) from a nearby object (67), so that the eye (60) can see the nearby object (67) clearly.

[0043] Figures 3E to 3F show examples of astigmatism and methods of correcting visual acuity to correct astigmatism. Referring to Figure 3E, astigmatism can refer to a type of refractive error resulting from rotational asymmetry in the refractive power of the eye (60). Astigmatism can cause distorted or blurred vision for objects at any given distance. Astigmatism can include simple hyperopic astigmatism, simple myopic astigmatism, etc. In an example of simple hyperopic astigmatism, the first focal point is on the retina (65) and the second focal point is behind the retina (65). In an example of simple myopic astigmatism, the first focal point is in front of the retina (65) and the second focal point is on the retina (65). Referring to Figure 3E, part of the object (64) is imaged on the retina (65) and the other part of the object (64) is imaged outside the retina (65) to form an image (61).

[0044] Referring to Figure 3F, in one example, astigmatism can be corrected by placing a cylindrical lens (72) in front of the eye (60). The cylindrical lens (72) and lens (63) can image an object (64) onto the retina (65) to form an image (61'). Eyeglasses for correcting astigmatism may be fitted with a corrective cylindrical lens that helps to properly refract light onto the retina (65) of the eye (60).

[0045] Diplopia can refer to the simultaneous perception of two images of a single object. The two images may be displaced or moved relative to each other, for example, horizontally or vertically. In diplopia, a single object may be imaged on two partially overlapping images. Binocular diplopia (or binocular diplopia) can refer to a type of diplopia in which two images are seen by each of the observer's eyes, and the two images are perceived by the observer as being shifted or partially overlapping relative to each other.

[0046] Lenses containing prism correction (e.g., prism glass) can correct diplopia, such as binocular diplopia. In one example, prism correction can merge a double image into a single clear image by shifting one of two images (e.g., seen in the right eye) relative to the other image (e.g., seen in the left eye). Prism glass has a lens made of prisms that can bend light before it hits the retina and shifts the image position. Lenses containing prism correction can displace the viewing image horizontally, vertically, or in any suitable direction (e.g., a combination of both directions). By shifting the image in front of the misaligned eye, diplopia (e.g., binocular diplopia) can be corrected.

[0047] Prism correction can be measured by two parameters: the prism diopter (PD) and the orientation or direction of the prism, indicated by the position of the base. Figure 3G shows a prism (80) used to correct diplopia. The prism (80) has two edges, including a base (81) and a apex (82). The base (81) can be the thickest part of the prism (80) (e.g., the thickest edge) and can be on the opposite side of the apex (82). Light can be bent toward the base (81) and the image can be moved toward the apex (82).

[0048] In one example, the orientation of the prism includes a base out (BO) indicating the base (81) facing the wearer's ear, a base in (BI) indicating the base (81) facing the wearer's nose, a base up (BU) indicating the base (81) facing upwards, and a base down (BD) indicating the base (81) facing downwards.

[0049] A prism diopter can indicate the prism power, or the amount of prism correction for correcting diplopia. A prism diopter can indicate prism deflection. A prism diopter may depend on the prism angle or vertex angle. The prism angle can be the angle Δ between the two surfaces (85) and (86) through which the light beam (84) enters and exits the prism (80).

[0050] Referring to Figure 3G, a light beam (84) incident on the surface (86) of the prism (80) is deflected by the prism (80) and exits from the surface (85) of the prism (80) at a deflection angle β. The deflection angle β may depend on at least the prism angle Δ. In one example, a prism diopter of 1 (or 1Δ or 1PD) represents a displacement of 1 unit of the bent light beam measured in 100 units from the prism (80). Referring to Figure 3G, a prism diopter of 1 can represent a displacement of 1 cm of the light beam (84) at 100 cm (1 meter). The prism (80) can have 8 prism diopters, which deflect the light beam (84) by 8 cm on a plane placed at a distance of 1 m.

[0051] By bending lenses, visual impairments such as astigmatism can be corrected. In some cases, the curvature profile of a curved lens may not be precisely controlled to correct visual impairments such as astigmatism. According to some embodiments of this disclosure, a visual correction adapter, such as a mechanical adapter, may be configured to bend and / or move a lens (e.g., a plastic curved mirror) in a reflective / refractive VR optical system to enable the correction of visual impairments, including hyperopia, myopia, astigmatism, and / or diplopia. By controlling the shape of the visual correction adapter (e.g., a mechanical adapter) and positioning the visual correction adapter adjacent to the lens, the shape of the lens can be controlled more precisely than bending the lens without a visual correction adapter.

[0052] Figures 4A to 4H show examples of vision correction adapters. Figures 4A to 4B show an example of a vision correction adapter (401) used to correct myopia or hyperopia according to one embodiment of the present disclosure. Figure 4B shows a side view of the vision correction adapter (401) in the XZ plane or YZ plane. The central region of the vision correction adapter (401) may include an opening (404). The thickness of the vision correction adapter (401) may be selected to correct myopia or hyperopia. The thickness of the vision correction adapter may vary depending on the degree of myopia or hyperopia. In one example, the vision correction adapter (401) is a circular band (or ring shape) between two surfaces (402) to (403). The two surfaces (402) to (403) can have any suitable shape. In the example of Figures 4A to 4B, the two surfaces (402) to (403) are, for example, parallel planes parallel to the XY plane. The vision correction adapter (401) is positioned between the first lens and the second lens in the optical system such that the first lens and the second lens are separated by the thickness T of the vision correction adapter (401), and as shown in Figures 5A to 5D, the refractive power of the optical system can be controlled to correct myopia or hyperopia.

[0053] Refractive power can indicate the degree to which an optical system or component (e.g., a lens or a curved mirror) focuses or diverges light. In one example, the refractive power of an optical component or system is indicated by the diopter (or optical diopter) parameter. The diopter can be equal to the reciprocal of the focal length f of the optical component or system. High refractive power indicates (i) strong focusing refractive power of a focusing optical component / system, or (ii) strong divergent refractive power of a divergent optical component / system.

[0054] The relative diopter parameter can indicate the difference between the first diopter of an optical system with visual acuity correction and the second diopter of an optical system without visual acuity correction. The relative diopter can indicate the degree of visual acuity correction for (i) myopia or hyperopia, or (ii) astigmatism.

[0055] Figures 5A to 5C are side views showing a display system (e.g., a near-eye display system) (100) according to several embodiments of the present disclosure. The display system (100) includes an optical system (110), a display device (120), a shift block (170), a controller (180), and the like. The optical system (110) may include any suitable optical elements such as diffracting elements (gritzes and prisms), refractive elements (lenses), inducting elements (e.g., plane waveguides and / or fibers), and polarizing elements (e.g., polarizers, half-wave plates, quarter-wave plates, polarizing rotors, Pancharatnam-Berry (PB) phase lenses, etc.).

[0056] The optical system (110) may include a lens system (130), a beam splitter (BS) (141), a reflecting polarizer (139), and the like. In one example, the optical system (110) includes a waveplate such as a quarter-wave plate (QWP) (142). The display device (120) may include a pixel array configured to emit a light beam to display an image. The optical system (110) can direct a beam of light emitted from an object A on the display device (120) (e.g., image A displayed on the display device (120)) or a real object to a viewing position or an area (or viewing area) (151) at the viewing position. In one example, the area (151) is located in the XY plane. In one example, the area (151) is called the exit pupil of the display system (100). The XY plane includes the X axis and the Y axis perpendicular to the X axis. A light receiver or detector, such as the user's eye (60), may be placed in area (151). In one example, a lens (63) in the eye (60) forms an image A' on the retina (65) of the eye (60) based on object A, and the eye (60) perceives object A on the display device (120) as a virtual image A'' on the image plane (199A) in Figure 5A. The virtual image A'' is at a distance D2 from area (151). A It appears larger than image A on the display device (120). Distance D2 A This is greater than, and in some cases much greater than, the distance D1 between area (151) and display device (120).

[0057] An optical cavity can be formed between the beam splitter (141) and the reflecting polarizer (139). In the example shown in Figure 5A, the optical cavity may include a lens system (130) and a QWP (142). As will be described later, the optical path of the light rays in the light beam may be folded within the optical cavity between the beam splitter (141) and the reflecting polarizer (139). Thus, the display system (100) can be an NED system (e.g., a HMD system worn by a user), and the optical system (110) and display device (120) can be positioned within the user's (e.g., eye (60)) eye distance threshold (e.g., 35 mm).

[0058] The lens system (130) may include one or more lenses, such as a first lens (131) and a second lens (132). The first lens (131) may include a light-transmitting member (145) having two opposing surfaces (135) to (136). The second lens (132) may include a light-transmitting member (146) having two opposing surfaces (137) to (138). The optical axis (160) of the lens system (130) may be parallel to the Z axis perpendicular to the XY plane. The first lens (131) and the second lens (132) may be circularly symmetric about the optical axis (160). For example, in Figure 5A, the first refractive power of the first lens (131) along the X-axis is equal to the second refractive power of the first lens (131) along the Y-axis, and the first refractive power of the second lens (132) along the X-axis is equal to the second refractive power of the second lens (132) along the Y-axis.

[0059] The surfaces of one or more lenses in the lens system (130), such as surfaces (135) to (138), can have any suitable shape or surface curvature, such as a planar shape parallel to the XY plane, a sphere with any suitable radius of curvature, an aspherical shape, or other shapes. One or more of the surfaces (135) to (138) may be smooth. One or more of the surfaces (135) to (138) may have grooves, including microstructures such as Fresnel structures. The shape of the surfaces (135) to (138) may be determined based on design parameters such as focal length, aberration requirements, lens thickness, and lens flatness. One or more lenses may include converging and / or diverging lenses. The second lens (132) may be a spherical-spherical lens, a planar-spherical lens, an aspherical-spherical lens, an aspherical-aspherical lens, etc. In the example of Figure 5A, the surface (136) of the first lens (131) is planar. The first lens (131) may be a planar-aspherical lens. The second lens (132) may be a planar-spherical lens. In one example, the first lens (131) and the second lens (132) are converging lenses each having a positive focal length.

[0060] The light-transmitting members (145) to (146) may include, but are not limited to, any suitable material including glass (e.g., borosilicate glass, high-density flint glass), polymers, and plastic materials. Examples of plastic materials include poly(methyl methacrylate) (PMMA), polyimide, acrylic, styrene, cyclic olefin polymers, cyclic olefin copolymers, and polycarbonate. Glass lenses may be manufactured by grinding, polishing, glass molding, etc. Polymer or plastic lenses may be manufactured by diamond turning, polishing, injection molding, casting, etc.

[0061] In some embodiments, one or more lenses in the lens system (130) may be flexible. A lens (e.g., a first lens (131) or a second lens (132)) can be made flexible by having a thickness below a threshold (e.g., mechanically thin) to impart flexibility. Light-transmitting members (145) and / or light-transmitting members (146) may contain cyclic olefin copolymers (COC) and / or PMMA to improve durability and / or flexibility.

[0062] The beam splitter (141) and the reflective polarizer (139) may be placed between the area (151) and the display device (120). The quarter-wave plate (142) may be placed between the beam splitter (141) and the reflective polarizer (139). An anti-reflective (AR) coating may be applied to any suitable surface of the optical system (110) to reduce undesirable reflections of the light beam, for example, to reduce or eliminate ghosting due to multiple reflections at various interfaces. The beam splitter (141), the reflective polarizer (139), and / or the quarter-wave plate (142) may be thin film optical components, for example, comprising one or more layers of an optical film. The thickness (e.g., maximum or average thickness) of the thin film optical components (e.g., beam splitter (141), reflective polarizer (139), or quarter-wave plate (142)) may be less than a thickness threshold such as 200 microns or 100 microns. A thin film optical component (e.g., BS(141), reflective polarizer(139), or quarter-wave plate(142)) can be placed on the surface of the first lens(131) or the second lens(132). The shape of the thin film optical component (e.g., BS(141), reflective polarizer(139), or quarter-wave plate(142)) may substantially or completely match the shape of the surface of the first lens(131) or the second lens(132).

[0063] A reflective polarizer (139) may be configured to allow a light beam having a first linearly polarized state to pass through and to reflect a light beam having a second linearly polarized state. The second linearly polarized state is orthogonal to the first linearly polarized state. The reflective polarizer (139) may be formed on the surface (e.g., (136)) of the lens system (130). The reflective polarizer (139) may be placed on the surface (136) of the first lens (131). The shape of the reflective polarizer (139) may substantially or completely match the shape (e.g., planar, spherical, aspherical, etc.) of the surface (136) of the first lens (131). In the example shown in Figure 5A, the shape of the reflective polarizer (139) is planar.

[0064] A beam splitter (141) may be configured to partially transmit and partially reflect a light beam incident on it. The beam splitter (141) may have an average light transmittance T and an average light reflectance R. In one example, the sum of T and R is 1 (i.e., 100%) over a wavelength range (e.g., 380–780 nanometers (nm)). The average light transmittance T and average light reflectance R of the beam splitter (141) can be denoted as T / R. T or R may be in a range (e.g., 40%–60%). In one example, the beam splitter (141) may have a T / R of 40 / 60, 50 / 50, or 60 / 40. For example, if T and R are 50%, the beam splitter (141) transmits 50% of the light beam incident on it and reflects 50%. The beam splitter (141) partially transmits and partially reflects a light beam from a display device (120) or a real object. In one example, BS(141) is positioned on the surface (137) of a second lens (132). The surface (137) of the second lens (132) can have any suitable shape, such as aspherical or spherical. The shape of BS(141) may substantially or completely match the shape of the surface (137) of the second lens (132) (e.g., spherical or aspherical shape).

[0065] The polarization state of a light beam can be altered when the light beam passes through a specific optical element. In one embodiment, the polarization state of a light beam can be altered by a waveplate or phase difference plate when the light beam passes through a waveplate. A quarter-wave plate (142) can alter the polarization state of a light beam passing through it by, for example, 90° or π / 2. In one example, the quarter-wave plate (142) converts linearly polarized light to circularly polarized light, or circularly polarized light to linearly polarized light. The quarter-wave plate (142) can be formed on the surface (135) of a lens system (130).

[0066] A light beam can be randomly polarized if it contains a series of rapidly changing polarization states. The light beam can be linearly polarized (e.g., in a linearly polarized state), circularly polarized (e.g., in a circularly polarized state), or elliptically polarized (e.g., in an elliptically polarized state). In the case of linear polarization, the electric field vector of the light beam lies along a specific line. In the case of circular polarization, the electric field vector of the light beam rotates, for example, clockwise or counterclockwise, as viewed from an observer in the direction the light beam is traveling.

[0067] Degree of polarization (DOP) is a quantity that indicates a portion of a polarized electromagnetic wave (e.g., a light beam). A fully polarized wave can have a DOP of 100%, while an unpolarized wave can have a DOP of 0%. A partially polarized wave can be represented by a superposition of polarized and unpolarized components, and therefore can have a DOP between 0% and 100%. DOP can be calculated as the percentage of the total power carried by the polarization component of the wave (e.g., a light beam).

[0068] A light beam (for example, a light beam generated from each pixel in a display device (120)) can have any suitable polarization state or DOP. In one example, the light beam is circularly polarized with 100% DOP. In another example, the light beam is primarily circularly polarized and has a relatively large DOP exceeding a threshold (e.g., 80% or more), such as a superposition of (i) a circularly polarized component and (ii) an unpolarized component and / or another polarization component. A circularly polarized beam with 100% DOP, or a primarily circularly polarized light beam with a relatively large DOP, may be referred to as a circularly polarized beam in this disclosure. In another example, the light beam is linearly polarized with 100% DOP, or primarily linearly polarized with a relatively large DOP exceeding a threshold. A linearly polarized beam with 100% DOP, or a primarily linearly polarized beam with a relatively large DOP, may be referred to as a linearly polarized beam in this disclosure.

[0069] The display device (120) may include a pixel array. In some examples, the pixel array includes a plurality of pixels arranged to form a two-dimensional surface. The two-dimensional surface of the display device (120) may be substantially flat or planar, curved, or include a combination of flat and planar panels. The display device (120) may be a display panel. The display device (120) may include any suitable type of display panel, such as a liquid crystal display (LCD) panel or an organic light-emitting diode (OLED) panel. The resolution of the display device (120) may be defined according to the two dimensions of the pixels or one of the two dimensions of the two-dimensional surface. Each pixel in the pixel array may generate a light beam. Each light beam may include a beam of rays in any suitable direction. For example, a light beam emitted by a pixel on object A on the display device (120) includes a beam of rays in a suitable direction. A subset of rays (124) in the light beam may be directed towards an area (151) by an optical system (110). The angular span of the subset (124) of the light beam can be determined based on the allowable angle ω of the optical system (110). Three rays (121) to (123) of the subset (124) of the light beam are shown in Figure 5A. The three rays (121) to (123) may include two boundary rays (121) and (123) and a central ray (122). In one embodiment, the light beam generated by the display device (120) can be circularly polarized or linearly polarized.

[0070] The optical system (110) may be configured to modify a light beam generated by a display device (120) or a real object and direct the modified light beam toward an area (151). The optical system (110) may be positioned between the display device (120) and the area (151). A second lens (132) may be positioned between the first lens (131) and the display device (120). In one example, the first lens (131) may be called an eye lens depending on its proximity to the area (151) (e.g., an eye (60)), and the second lens (132) may be called a display lens depending on its proximity to the display device (120).

[0071] In Figure 5A, a beam splitter (141) is positioned on the surface (137) of the second lens (132), and a reflective polarizer (139) is positioned on the surface (136) of the first lens (131). An optical cavity may be formed between the beam splitter (141) and the reflective polarizer (139). A quarter-wave plate (142) is formed on the surface (135) of the first lens (131).

[0072] According to one embodiment of the present disclosure, the optical system (110) may include a vision correction adapter (401). The optical cavity may include a lens system (130), a distance or gap (197) between a first lens (131) and a second lens (132), and a QWP (142). The distance or gap (197) between the first lens (131) and the second lens (132) may refer to the distance (or gap) between the vertex V1 of the first lens (131) (e.g., the intersection of the surface (135) and the optical axis (160)) and the vertex V2 of the second lens (132) (e.g., the intersection of the surface (138) and the optical axis (160)). The gap (197) between the first lens (131) and the second lens (132) may be determined by the vision correction adapter (401) (e.g., the thickness of the vision correction adapter (401)). The thickness T between the surfaces (402) and (403) of the vision correction adapter (401) may be the same as the gap (197) between the first lens (131) and the second lens (132).

[0073] The vision correction adapter (401) includes a circular band between two parallel surfaces. The central region of the vision correction adapter (401) may include an opening. Referring to Figure 5A, the thickness T of the vision correction adapter (401) may be selected as a threshold thickness (e.g., value T1) so that the beam of light from the pixels on the display device (120) (e.g., rays (121) to (123)) can become collimating rays (or substantially collimating rays) between the optical system (110) and the area (151), and so that the vision correction adapter (401) does not correct myopia or hyperopia. If the beam of light from the pixels on the display device (120) is collimated, the distance D2 A It can become infinite. In some examples, the distance D2 A This can be relatively large, for example, more than 1 meter (e.g., 2 m), if the beams of light from the pixels on the display device (120) are substantially collimated. If the eye (60) is neither nearsighted nor farsighted, an object on the display device (120) (e.g., object A) may be imaged on the retina (65) of the eye (60) without vision correction, and the eye (60) can see object A clearly.

[0074] The light beam emitted from the display device (120) can partially pass through the beam splitter (141). The light beam then passes through the optical cavity multiple times. In one example, the light beam first passes through the optical cavity and is reflected by the reflective polarizer (139). Next, the light beam passes through the optical cavity a second time and is partially reflected by the beam splitter (141). After passing through the optical cavity a third time, the light beam passes through the reflective polarizer (139) and reaches area (151).

[0075] The optical system (110) includes a reflector-refractor optical system. For example, the reflector-refractor optical system (110) includes (i) a refractive optical component (e.g., a lens system (130)) and (ii) a reflective optical component (e.g., a beam splitter (141) acting as a reflector for reflecting light and a reflective polarizer (139) acting as a reflector for reflecting light).

[0076] The reflecting / refracting optical system (110) may include a polarizing reflecting / refracting optical system. For example, each time the light beam passes through the QWP (142), the polarization state of the light beam is manipulated by the QWP (142). Thus, the light beam is in one polarization state and is reflected by the reflecting polarizer (139) after the first pass, and the light beam is in another polarization state and is transmitted by the reflecting polarizer (139) after passing through the optical cavity a third time.

[0077] The optical system (110) may also be referred to as a folding optical system. Because the light beam is reflected between the beam splitter (141) and the reflecting polarizer (139) and travels multiple times (e.g., three times) within the optical cavity, the optical path between the display device (120) and the area (151) includes a folding path (125) between the beam splitter (141) and the reflecting polarizer (139). Folding of the optical path can reduce the distance D1, and the display system (100) including the optical system (110) may be used as a NED system. In one example, the lens system (130) is designed to have a relatively thin thickness D5 and may be referred to as a pancake lens system.

[0078] Referring to Figure 5A, the light ray (122) emitted from the display device (120) partially passes through the beam splitter (141). Subsequently, the light ray (122) first passes through the optical cavity, and then sequentially passes through the second lens (132), the gap (197), the QWP (142), and the first lens (131).

[0079] After the light ray (122) first passes through the optical cavity, the light ray (122) is reflected back into the optical cavity by the reflecting polarizer (139). Subsequently, the light ray (122) passes through the optical cavity a second time, this time passing through the first lens (131), QWP (142), gap (197), and second lens (132) in sequence.

[0080] After the ray (122) passes through the optical cavity for the second time, the ray (122) is partially reflected back into the optical cavity by the beam splitter (141). Subsequently, the ray (122) passes through the optical cavity for the third time, where it sequentially passes through the second lens (132), the gap (197), the QWP (142), and the first lens (131). The ray (122) then passes through the reflecting polarizer (139) and proceeds to area (151). In one example, the ray (122) is focused onto the retina (65) by the lens (63) of the eye (60), and the eye (60) perceives the ray (122) as if it were coming from a virtual point on a virtual image A''.

[0081] A light beam emitted from a pixel in the display device (120) can be circularly polarized, for example, in a first circularly polarized state. A beam splitter (141) partially transmits the light ray (122) in the first circularly polarized state. The light ray (122) then passes through the optical cavity as described above. During the first pass, the first circularly polarized state of the light ray (122) is converted to a second linearly polarized state by the QWP (142). The second linearly polarized state is aligned with the blocking direction of the reflecting polarizer (139). The blocking direction of the reflecting polarizer (139) refers to the direction in which the light beam is blocked by the reflecting polarizer (139) and does not pass through the reflecting polarizer (139) if the electric field vector of the light beam is aligned with the blocking direction. The reflecting polarizer (139) reflects a ray (122) having a second linear polarization state with a relatively high average reflectivity of a constant value (e.g., 90%) or more over a wavelength range (e.g., 380 nm to 780 nm). The ray (122) then passes through the optical cavity a second time as described above, and the ray (122) is partially reflected by the beam splitter (141). Subsequently, the ray (122) passes through the optical cavity a third time as described above. During both the second and third passes, the QWP (142) changes the polarization state of the ray (122). This converts the second linear polarization state of the ray (122) to a first linear polarization state parallel to the transmission direction of the reflecting polarizer (139). Therefore, the reflective polarizer (139) transmits a ray (122) having a first linear polarization state, thereby directing the ray (122) towards area (151) with a relatively high transmittance of a constant value (e.g., 90%) or more over the wavelength range (e.g., 380 nm to 780 nm). Referring to Figure 5A, the optical path includes a folding path (125) between the reflective polarizer (139) and the beam splitter (141) due to the change in polarization.

[0082] As described above in Figure 5A, when the thickness T of the vision correction adapter (401) has a threshold thickness or value T1 (e.g., 2.44 mm or 2.566 mm), the vision correction adapter (401) positioned between the first lens (131) and the second lens (132) in the optical system (110) does not provide vision correction for myopia, nor does it provide vision correction for hyperopia. Referring to Figure 5A, the first lens (131) and the second lens (132) are separated by the thickness T1 of the vision correction adapter. The relative optical diopter corresponding to Figure 5A can be 0.

[0083] The display system (100) and optical system (110) in Figure 5B are described in Figure 5A, with the following differences. In one example, the eye (60) in Figure 5B is myopic. According to one embodiment of the present disclosure, the thickness T of the vision correction adapter (401) can be less than a threshold thickness, or value T1, for correcting myopia, as shown in Figure 5B. Referring to Figure 5B, the thickness T of the vision correction adapter (401) in the optical system (110) is less than value T1, and the optical system (110) can form a virtual image B'' on the image plane (199B) in Figure 5B based on an object A on the display device (120). The distance D2 between the image plane (199B) and the area (151) B (For example, 100mm) is distance D2 A It can be made smaller than this. The lens (63) in the eye (60) forms an image B' on the retina (65) of the eye (60) based on the virtual image B'', thereby the eye (60) can clearly see object A on the display device (120) by visual correction provided by reducing the gap (197) between the first lens (131) and the second lens (132).

[0084] Referring to FIG. 5B, the thickness T of the vision correction adapter (401) (for example, a value T2 such as 0.02 mm) is less than the threshold thickness (or value T1) so that the light beam (for example, light rays (121)-(123)) from the pixels on the display device (120) can become divergent light rays between the optical system (110) and the area (151), and the vision correction adapter (401) is configured to correct myopia. A lens system (130) in which the gap (197) (for example, equal to T2) between the first lens (131) and the second lens (132) is less than the threshold thickness can function as a diverging lens having a negative refractive power (for example, the negative relative diopter shown in FIG. 5D).

[0085] Referring to FIG. 5B, the first lens (131) and the second lens (132) are separated by the thickness T2 of the vision correction adapter. The relative optical diopter corresponding to FIG. 5B can be less than 0. The distance D2 B can be relatively small. For example, D2 B is D2 A less than. Referring to FIG. 5B, the optical system (110) includes a vision correction adapter (401) having a thickness T2 for separating the first lens (131) and the second lens (132), and the optical system (110) can image an object (for example, object A) on the display device (120) onto the retina (65) of the myopic eye (60), and the eye (60) can clearly see object A.

[0086] According to an embodiment of the present disclosure, the thickness T of the vision correction adapter (401) can be made greater than the threshold thickness (or value T1) for correcting hyperopia, as shown in FIG. 5C.

[0087] The display system (100) and optical system (110) in Figure 5C are described in Figure 5A, with the following differences. In one example, the eye (60) in Figure 5C is hyperopic. According to one embodiment of the present disclosure, the thickness T of the vision correction adapter (401) can be greater than the threshold thickness (or value T1) for correcting hyperopia, as shown in Figure 5C. Referring to Figure 5C, the thickness T of the vision correction adapter (401) in the optical system (110) is greater than the value T1, and the optical system (110) can form a virtual image C'' on the image plane (199C) in Figure 5C based on an object A on the display device (120). Comparing Figures 5B and 5C, the image plane (199B) and image plane (199C) may be on opposite sides of area (151), with a distance D2 between the image plane (199C) and area (151). C The sign (for example, -100mm) indicates distance D2 B It may be the opposite sign of the given sign. For example, distance D2 B The value is positive, and the distance D2 C It is negative.

[0088] The lens (63) in the eye (60) forms an image C' on the retina (65) of the eye (60) based on the virtual image C'', so the eye (60) can clearly see object A on the display device (120) by correcting vision by increasing the gap (197) between the first lens (131) and the second lens (132).

[0089] Referring to Figure 5C, the thickness T of the vision correction adapter (401) (e.g., a value T3 such as 5.08 mm) is greater than the threshold thickness (or value T1), so that the beam of light rays from the pixels on the display device (120) (e.g., rays (121) to (123)) can become focused rays between the optical system (110) and the area (151), and the vision correction adapter (401) is configured to correct hyperopia. Referring to Figure 5C, the first lens (131) and the second lens (132) are spaced apart by the thickness T3 of the vision correction adapter. A lens system (130) where the gap (197) (e.g., equal to T3) between the first lens (131) and the second lens (132) is greater than the threshold thickness can function as a focusing lens with positive refractive power (e.g., positive relative diopters as shown in Figure 5D). The relative optical diopter corresponding to Figure 5C is greater than zero, which may indicate that the optical system (110) in Figure 5C is more focused than the optical system (110) in Figure 5A. Referring to Figure 5C, the optical system (110) includes a vision correction adapter (401) having a thickness T3 for separating a first lens (131) and a second lens (132), and the optical system (110) can image an object (e.g., object A) on a display device (120) onto the retina (65) of a farsighted eye (60), and the eye (60) can see object A clearly.

[0090] Figure 5D shows an example of vision correction for correcting myopia and hyperopia. The columns from left to right show the relative diopter, correction type (e.g., myopia correction or hyperopia correction), thickness of the vision correction adapter (401) (or the gap (197) between the vertex V1 of the first lens (131) and the vertex V2 of the second lens (132)), resolution of the display system (100) without vision correction (e.g., root mean square (RMS) size), and resolution of the display system (100) with vision correction as shown in Figures 5A-5C (e.g., RMS size).

[0091] For normal visual acuity without myopia or hyperopia (indicated in row (501)), no visual correction is applied to the display system (100), as shown in Figure 5A, and the relative diopter is 0, corresponding to a gap thickness T1 (e.g., 2.44 mm). The resolution is 3.2 microns.

[0092] The resolution of the uncorrected display system (100) can indicate the degree of myopia or hyperopia. The power of the relative diopter (e.g., value) may depend on the resolution of the uncorrected display system (100). For example, the larger the uncorrected RMS size, the larger the absolute relative diopter used to correct myopia or hyperopia. The thickness of the corrective adapter (401) or gap (197) may be determined based on the sign and the degree of relative diopter.

[0093] In the myopia shown by rows (502) to (505), visual acuity correction is applied to the display system (100) to correct the myopia, as shown in Figure 5B, with a relative diopter being negative, such as -7.5 to -0.5, and the gap being less than the threshold thickness (e.g., 2.44 mm), e.g., 0.54 mm to 2.31 mm. The resolution of the display system (100) can be significantly improved by correcting the myopia, for example, the resolution can be increased by approximately 10 to 200 times with the myopia correction shown by rows (502) to (505) (e.g., the RMS size without correction is approximately 10 to 200 times larger than the corresponding RMS size with correction).

[0094] For hyperopia as shown in rows (506) to (511), visual acuity correction is applied to the display system (100) to correct the hyperopia, as shown in Figure 5C, with a positive relative diopter of 0.49 to 8.5, and a gap greater than the threshold thickness (e.g., 2.44 mm), e.g., 2.56 mm to 4.58 mm. The resolution of the display system (100) can be significantly improved by correcting the hyperopia, for example, the resolution increases by approximately 10 to 200 times with the hyperopia correction shown in rows (506) to (511) (e.g., the uncorrected RMS size is approximately 10 to 117 times larger than the corresponding RMS size with correction).

[0095] As shown in Figure 5D, by changing the thickness T of the vision correction adapter (401), the separation or gap (197) between the first lens (131) and the second lens (132) can be controlled, and thus myopia or hyperopia can be corrected.

[0096] Figures 4C to 4D show an example of a vision correction adapter (411) used to correct astigmatism according to one embodiment of the present disclosure. Figure 4D shows a side view of the vision correction adapter (411) in the XZ plane.

[0097] Astigmatism can occur, for example, when the cornea or lens of the eye has an irregular shape. Astigmatism can cause images to appear blurred or distorted because light is not properly focused onto the retina of the eye. If the eye is uniformly rounded (e.g., ball-shaped), astigmatism will not occur. If the eye has an irregular shape (e.g., oval), astigmatism can occur. In one example, astigmatism is caused by the cornea and / or lens of the eye having an irregular shape (e.g., oval). For example, if the width of the eye is greater than the height of the eye, horizontal astigmatism may occur, and if the width of the eye is less than the height of the eye, vertical astigmatism may occur. With astigmatism, vision may be blurred.

[0098] Ocular astigmatism can be indicated by the degree and direction of the astigmatism. Relative diopters (e.g., cylindrical refractive power parameter or cylindrical power (CYL)) can measure the degree of ocular astigmatism in diopters and can be a negative or positive number. A larger cylindrical power (CYL) indicates greater astigmatism. The Axis parameter can be a number between 0° and 180° that indicates the direction of the astigmatism.

[0099] Cylindrical lenses can be used to correct astigmatism. The prescription for a cylindrical lens can specify the optical refractive power or cylindrical refractive power of the cylindrical lens (e.g., using the cylindrical power (CYL) parameter), as well as the axis on which the cylindrical lens is positioned (e.g., using the Axis parameter). For example, a cylindrical lens may have refractive power on a first axis and no refractive power on a second axis perpendicular to the first axis.

[0100] In some examples, the surface of a lens (e.g., a spherical lens having the same refractive power in a first axis and a second axis) may be bent or curved so that the surface of the lens can have different shapes, and thus the lens can have different refractive powers in two different axes (e.g., a first axis and a second axis) in order to correct astigmatism.

[0101] Referring to Figures 4C to 4D, the shape of the vision correction adapter (411) (e.g., cylindrical spacer adapter) may be based on astigmatism (e.g., degree and direction of astigmatism), and the vision correction adapter (411) may be configured to change the shape of one or more lenses (e.g., first lens (131)) in the optical system (110) to match the shape of the vision correction adapter (411) in order to correct astigmatism.

[0102] The vision correction adapter (411) may include a circular band between surfaces (412) and (413). The central region of the vision correction adapter (411) may include an opening. At least one of surfaces (412) and (413) is curved. As shown in Figures 4C, 4D, and 6A, surface (412) is a curved surface (412). The shape of the curved surface (412) may be based on the degree and direction of astigmatism (e.g., X-axis, Y-axis, etc.). The vision correction adapter (411) may be positioned in contact with the lens (e.g., (131)) such that the lens is bent based on the shape of the vision correction adapter (411). The surface of the lens may have different shapes in two different axes (e.g., a first axis and a second axis), and therefore the lens may have different optical refractive powers in two different axes (e.g., a first axis and a second axis) to correct astigmatism.

[0103] Figure 6A shows an example of vision correction for correcting astigmatism. Referring to Figure 6A, the display system (100) includes an optical system (110). The components of the optical system (110) and the display system (100) are shown in Figure 5A, with the following differences. The optical system (110) in Figure 6A includes a vision correction adapter (411). Referring to Figures 4C, 4D, and 6A, the curved surface (412) of the vision correction adapter (411) may be configured to change the shape of the first lens (131) to conform to the curved surface (412). The first lens may be flexible. The shape of the first lens may be precisely controlled or manipulated based on the shape of the vision correction adapter (411), such as the curved surface (412) of the vision correction adapter (411). In one example, the vision correction adapter (411) is positioned in contact with the first lens (131) (e.g., the peripheral region of the first lens (131)) such that the first lens (131) is bent according to the shape of the vision correction adapter (411). When the first lens (131) is bent, the shape of the first lens (131) may perfectly or substantially conform to the shape of the curved surface (412) of the vision correction adapter (411). In one example, the first lens (131) is mounted on the vision correction adapter (411) with an appropriate radius and axial orientation to correct astigmatism.

[0104] Referring to Figure 6A, in the XZ plane, the shapes of surfaces (135) to (136) change based on the shape of the curved surface (412) (for example, they are different from the surface shapes in Figures 5A to 5C). In the YZ plane, the shapes of surfaces (135) to (136) remain unchanged (for example, they are the same as the surface shapes in Figures 5A to 5C). The vision correction adapter (411) can independently change the first refractive power along the first axis (e.g., the X axis) of the first lens (131) and the second refractive power along the second axis (e.g., the Y axis) of the first lens (131), and thus can correct astigmatism. For example, the shape of the curved surface (412) is determined such that, based on the direction of astigmatism, the shape of the curved surface (412) changes along the X-axis but remains unchanged along the Y-axis, and therefore the vision correction adapter (411) changes the first refractive power along the X-axis of the first lens (131) but does not change the second refractive power along the Y-axis of the first lens (131).

[0105] The vision correction adapter (411) may be positioned at any suitable location within the optical system (110), for example, adjacent to one or more lenses whose shape the vision correction adapter (411) can change. In the example shown in Figure 6A, the vision correction adapter (411) is positioned between the first lens (131) and the second lens (132), and the vision correction adapter (411) is configured to change the shape of the first lens (131) but not the shape of the second lens (132). In some examples, the vision correction adapter (411) is configured to change the shape of both the first lens (131) and the second lens (132). In some examples, the vision correction adapter (411) is positioned outside the lens system (130), for example to the left of the first lens (131), and is configured to change the shape of the first lens (131).

[0106] Figure 6B shows an example for correcting astigmatism. The columns from left to right show the relative diopter (e.g., cylindrical refractive power along a single axis), cylindrical sagitta (or sag) (in millimeters (mm)), radius of curvature of the curved surface (412) of the vision correction adapter (411), resolution (e.g., RMS size) of the display system (100) with and without astigmatism correction, and resolution (e.g., RMS size) of the display system (100) with astigmatism correction, as shown in Figure 6A. The relative diopter can represent the cylindrical refractive power of a cylindrical lens having the same shape (e.g., the same radius of curvature) as the vision correction adapter (411). The cylindrical sagitta can represent the displacement along the optical axis (e.g., (160)) from the apex of the cylindrical surface (e.g., (412)). In one example, the relative diopter, cylindrical sagitta (or sag), and radius of curvature of the curved surface (412) of the vision correction adapter (411) are shown with respect to a single axis (e.g., the X-axis), while the relative diopter, cylindrical sagitta (or sag), and radius of curvature of the curved surface (412) of the vision correction adapter (411) with respect to the Y-axis are 0, 0 mm, and infinity, respectively. In one example, when the radius of curvature is infinite, the curved surface (412) is flat.

[0107] The resolution of the uncorrected display system (100) can indicate the degree of astigmatism. The power of the relative diopter (e.g., value) may depend on the resolution of the uncorrected display system (100). For example, the larger the uncorrected RMS size, the larger the absolute relative diopter used to correct the astigmatism. The radius of curvature (and cylindrical sag) of the curved surface (412) of the corrected adapter (411) can be determined based on the sign and degree of astigmatism.

[0108] In the case of normal visual acuity without astigmatism (indicated by row (601)), as shown in Figure 5A, no correction for astigmatism is applied to the display system (100), the relative diopter is 0, the cylindrical sagittal is 0 mm, and the radius of curvature of the curved surface (412) of the visual acuity correction adapter (411) is infinite. The resolution is 2.2 microns.

[0109] The relative diopter can be negative (e.g., indicated by rows (602)-(603)) or positive (e.g., indicated by rows (602)-(603)) to correct astigmatism. The resolution of the display system (100) can be significantly improved by correcting astigmatism, for example, the resolution can increase by about 10-30 times with astigmatism correction indicated by rows (602)-(606) (e.g., the RMS size without correction is about 10-30 times larger than the corresponding RMS size with correction).

[0110] As shown in Figure 3G, a prism can be used to move the first image formed by the optical system of the observer's first eye, so that the first image and the second image formed in the second eye can form a single image perceived by the observer. In one example, as shown in Figures 7A-7B, a lens with refractive power is tilted so that it functions as (i) a lens with the same or similar refractive power as the lens before tilting, and (ii) a prism configured to move the image.

[0111] Figures 7A and 7B show some examples of the display system (100) without diplopia correction (Figure 7A) and with diplopia correction (Figure 7B). The display system (100) in Figures 7A and 7B may or may not include a vision correction adapter (401).

[0112] The display system (100) in Figure 7A may be identical or similar to the display system (100) in Figure 5A, and the components related to the display system (100) are shown in Figure 5A. In one example, the display system (100) in Figure 7A does not include a vision correction adapter (401). In one example, a pixel (721) on the display device (120) (for example, located 2 mm above the center of the display device (120)) emits a beam of light containing a ray (711). The ray (711) can be directed towards an area (151) at a field of view α1 (for example, 5.3°), and a virtual image (722) is formed on the image plane (199A). A pixel (731) on the display device (120) (for example, located at the center of the display device (120)) emits a beam of light containing a ray (712). The light ray (712) can be directed towards the area (151) at an angle of view α2 (for example, 0°), and a virtual image (732) is formed on the image plane (199A).

[0113] In one example, the display system (100) in Figure 7B does not include a vision correction adapter (401). The display system (100) in Figure 7B may be identical to the display system (100) in Figure 7A, except that one of the lenses is inclined. Components related to the display system (100) in Figure 7B are shown in Figure 5A. Referring to Figure 7B, the first lens (131) is inclined at a tile angle α (e.g., 5°) between the surface (136) of the first lens (131) and the Y-axis. In one example, a pixel (731) on the display device (120) (e.g., located at the center of the display device (120)) emits a beam of light containing a ray (713). The ray (713) can be directed towards an area (151) at a field of view α3 (e.g., 5.3°), and a virtual image (751) is formed on the image plane (199A). A pixel (741) on the display device (120) (for example, located 2 mm below the center of the display device (120)) emits a beam of light containing a ray (714). The ray (714) can be directed towards area (151) at an angle of view α4 (for example, 0°), and a virtual image (752) is formed on the image plane (199A).

[0114] Referring to Figures 7A and 7B, when the first lens (131) is tilted, the image (e.g., the virtual image of pixel (731)) moves upward, for example, from the virtual image (732) in Figure 7A (without lens tilt) to the virtual image (752) in Figure 7B (with lens tilt). The tilt of the lens in the optical system (110) allows for image shifting, thereby merging binocular diplopia into a single vision (e.g., one image perceived by the observer), and thus correcting binocular diplopia.

[0115] According to one embodiment of the present disclosure, as shown in Figure 8A, a lens (e.g., a first lens (131)) can be attached to a vision correction adapter (e.g., a prism) to correct diplopia (e.g., binocular diplopia). Figure 8A shows an example of diplopia correction in a display system (100). The display system (100) in Figure 8A may be identical or similar to the display system (100) in Figure 7B. Components related to the display system (100) in Figure 8A are shown in Figures 5A and 7B. The optical system (110) of the display system (100) in Figure 8A may include a vision correction adapter (e.g., a prism) (801) having a prism angle Δ between surfaces (811) and (812). In one example, the central region of the prism (801) (marked by a dashed line in Figure 8A) includes an aperture. The inclination angle and orientation of the prism (801) may be based on the degree and orientation of diplopia, respectively. The tilt angle α of the prism (801) can be defined as the angle between the surface of the prism (801) and an axis (e.g., the optical axis (160), the Y-axis, the X-axis, etc.). In the example shown in Figure 8A, surface (812) is perpendicular to the optical axis (160) (e.g., parallel to the Y-axis), and surface (811) is tilted relative to surface (812) by a prism angle Δ (e.g., surface (811) is tilted by 90°-Δ relative to the optical axis (160)). Referring to Figure 8A, the tilt angle α with respect to the Y-axis is equal to Δ.

[0116] The prism (801) may be configured to tilt the first lens (131) according to the tilt angle α and the orientation of the prism (801) (e.g., BO, BI, BU, BD, etc.) in order to correct diplopia. The prism (801) may be positioned in contact with the first lens (131) (e.g., the peripheral region of the first lens (131)) such that the first lens (131) is tilted based on the tilt angle α and the orientation of the prism (801). The prism (801) may be positioned at any suitable position within the optical system (110) (e.g., to the left or to the right of the first lens (131)).

[0117] Figure 8B shows an example of correcting diplopia. The columns, from left to right, show the tilt angle (e.g., tilt angle α in Figures 7B and 8A), prism diopter, field of view (e.g., α3 in Figure 7B), and resolution (e.g., RMS size) of the display system (100) with diplopia corrected. The field of view in Figure 8B may correspond to the field of view (e.g., α3 in Figure 7B) of the virtual image (e.g., (751)) of the pixel (e.g., (731)) at the center position of the display device (120). The field of view may depend on the tilt angle (or prism diopter). As the tilt angle increases, the RMS size with diplopia correction increases slightly, which may slightly decrease the resolution of the display system (100). The greater the degree of diplopia, the larger the tilt angle may be.

[0118] Visual impairments such as myopia / hyperopia, astigmatism, and diplopia can be individually corrected by placing a visual correction adapter (e.g., (401), (411), or (801)) within the optical system (110), as shown in Figures 5A-5D, 6A-6B, and 8A-8B. In some embodiments, multiple visual impairments, such as multiple myopia / hyperopia, astigmatism, and diplopia, can be corrected based on a single visual correction adapter.

[0119] In one example, myopia / hyperopia and astigmatism are corrected by a vision correction adapter. The shape of the vision correction adapter is determined based on astigmatism (for example, as shown in Figures 4C-4D and 6A-6B), and the thickness of the vision correction adapter is determined based on myopia / hyperopia (for example, as shown in Figures 4A-4B and 5A-5D). The vision correction adapter may be positioned between the first lens (131) and the second lens (132) such that the gap (197) between the first lens (131) and the second lens (132) is based on the thickness T of the vision correction adapter, and the shapes of the first lens (131) and the second lens (132) are modified based on the shape of the vision correction adapter.

[0120] In one example, myopia / hyperopia and diplopia are corrected by a vision correction adapter. The shape of the vision correction adapter (e.g., a prism with a specific prism angle) is determined based on diplopia (e.g., as shown in Figures 3G and 8A-8B), and the thickness T of the vision correction adapter is determined based on myopia / hyperopia (e.g., as shown in Figures 4A-4B and 5A-5D). The vision correction adapter may be positioned between the first lens (131) and the second lens (132) such that the gap (197) between the first lens (131) and the second lens (132) is based on the thickness T of the vision correction adapter, and one of the first lens (131) and the second lens (132) is tilted based on the tilt angle of the vision correction adapter. In one example, the tilted surface of the vision correction adapter is tilted with respect to an axis (e.g., the Y-axis or optical axis (160) of the optical system (110)). The inclination angle and orientation of the inclined surface of the vision correction adapter can be based on diplopia. The vision correction adapter may be configured to inclinate the first lens (131) according to the inclination angle and orientation of the inclined surface of the vision correction adapter in order to correct diplopia.

[0121] In one example, astigmatism and diplopia are corrected by a vision correction adapter. The shape of the vision correction adapter is determined based on astigmatism and diplopia. The vision correction adapter may be positioned between the first lens (131) and the second lens (132) such that one of the first lens (131) and the second lens (132) is tilted based on the tilt angle of the vision correction adapter, as described above. Furthermore, one of the first lens (131) and the second lens (132) is bent to correct astigmatism, as described in Figure 6A. In one example, a single lens is tilted and bent by a vision correction adapter to correct astigmatism and diplopia. In one example, one of the first lens (131) and the second lens (132) is tilted by a vision correction adapter to correct diplopia, and the other of the first lens (131) and the second lens (132) is bent by a vision correction adapter to correct astigmatism.

[0122] Figures 4E to 4G show an example of a vision correction adapter (421) used to correct astigmatism and diplopia according to one embodiment of the present disclosure. Figure 4F shows a side view of the vision correction adapter (421) in the XZ plane. Figure 4G shows a side view of the vision correction adapter (421) in the YZ plane.

[0123] Referring to Figures 4E to 4G, the shape of the vision correction adapter (421) may be based on astigmatism (e.g., degree and direction of astigmatism) and diplopia, and the vision correction adapter (421) may be configured to change the shape of one or more lenses (e.g., a first lens (131) and a second lens (132)) in the optical system (110) to match the shape of the vision correction adapter (421) in order to correct astigmatism and diplopia.

[0124] The vision correction adapter (421) may include a circular band between surface (422) and surface (424). The central region of the vision correction adapter (421) may include an opening. At least one of surfaces (422) and (424) is curved. In the examples shown in Figures 4E to 4G, surface (422) is the same or similar curved surface (422) as the curved surface (412) described in Figures 4C, 4D, and 6A. The shape of the curved surface (422) may be based on the degree and direction of astigmatism. The vision correction adapter (421) may be positioned in contact with the lens (e.g., the shape of the curved surface (422)) such that the lens (e.g., (131)) is bent according to the shape of the vision correction adapter (421). When a lens is bent, the surface of the lens can have different shapes in two different axes (e.g., the X-axis and the Y-axis), and therefore the lens can have different refractive powers in two different axes (e.g., the X-axis and the Y-axis) to correct astigmatism. Referring to Figures 4F to 4G, the surface (422) is a cylindrical surface that is curved in the XZ plane and flat in the YZ plane.

[0125] The curved surface (422) of the vision correction adapter (421) may be configured to change the shape of the first lens (131) to conform to the curved surface (422), as described above. In one example, the vision correction adapter (421) is positioned in contact with the first lens (131) (e.g., the peripheral region of the first lens (131)) such that the first lens (131) is bent based on the curved surface (422) of the vision correction adapter (421). In one example, the first lens (131) is attached to the vision correction adapter (421).

[0126] In one example, in the XZ plane, the shapes of surfaces (135) to (136) are changed based on the shape of the curved surface (422) (different from the shapes of surfaces (135) to (136) in Figures 5A to 5C). In the YZ plane, the shapes of surfaces (135) to (136) remain unchanged (for example, identical to the shapes of the surfaces in Figures 5A to 5C). The vision correction adapter (421) can change the first refractive power along the first axis (e.g., the X-axis) of the first lens (131) and the second refractive power along the second axis (e.g., the Y-axis) of the first lens (131) to be different, and thus correct astigmatism. For example, referring to Figures 4F to 4G, the shape of the curved surface (422) changes along the X-axis but not along the Y-axis. Therefore, the vision correction adapter (421) changes the first refractive power along the X-axis of the first lens (131) but does not change the second refractive power along the Y-axis of the first lens (131).

[0127] Referring to Figures 4F to 4G, the surface (424) can be tilted at an inclination angle Δ (for example, with respect to the Y-axis), and the surface (424) of the vision correction adapter (421) is positioned in contact with the second lens (132), as described in Figure 8A, so that the second lens (132) can be tilted at an inclination angle Δ to correct diplopia.

[0128] The vision correction adapter (421) may be positioned at any suitable location within the optical system (110), for example, adjacent to one or more lenses from which the vision correction adapter (421) can change shape. In this example, the vision correction adapter (421) is positioned between a first lens (131) and a second lens (132), and the vision correction adapter (421) is configured to change the shape of the first lens (131) based on the shape of its surface (422), and to tilt the second lens (132) based on the shape of its surface (424).

[0129] Referring to Figures 4E to 4G, in one example, the vision correction adapter (421) includes a vision correction adapter (411) configured to correct astigmatism and a prism (451) configured to correct diplopia. The descriptions of prisms (80) and (801) can be appropriately applied to prism (451). The vision correction adapter (411) and prism (451) can be attached to the interface (423).

[0130] Figure 4H shows an example of a vision correction adapter (421) used to correct astigmatism and diplopia according to one embodiment of the present disclosure. Figure 4H shows a side view of the vision correction adapter (421) in the XZ plane. The descriptions of Figures 4E to 4G may be appropriately adapted to the vision correction adapter (421) of Figure 4H. The surface (422) of Figure 4H may be identical to the surface (422) described in Figures 4E to 4G. The surface (424) of Figure 4H differs from the surface (424) of Figures 4E to 4G as follows. The surface (424) of Figure 4H may be tilted at an angle Δ with respect to the X axis, and the surface (424) of the vision correction adapter (421) of Figure 4H may be positioned in contact with a lens, similar to the one described in Figure 8A, to tilt the lens and correct diplopia.

[0131] Visual impairments, including myopia / hyperopia, astigmatism, and diplopia, can be corrected using a single vision correction adapter. For example, the thickness of a vision correction adapter (421) configured to correct astigmatism and diplopia is selected to correct either myopia or hyperopia, and the vision correction adapter (421) is placed between a first lens (131) and a second lens (132), with the first lens (131) and the second lens (132) separated by the thickness of the vision correction adapter (421). Thus, the vision correction adapter (421) can correct myopia / hyperopia, astigmatism, and diplopia.

[0132] In some examples, multiple vision correction adapters are used in the optical system (110) to correct myopia / hyperopia, astigmatism, and / or diplopia. A first vision correction adapter can correct one or more of myopia / hyperopia, astigmatism, and diplopia, and a second vision correction adapter can correct another one of myopia / hyperopia, astigmatism, and diplopia, different from one or more of myopia / hyperopia, astigmatism, and diplopia. In one example, the first vision correction adapter is configured to correct myopia / hyperopia, and the second vision correction adapter can correct astigmatism and / or diplopia. Multiple vision correction adapters can be placed in any suitable position within the optical system (110). In one example, a first vision correction adapter is positioned between the first lens (131) and the second lens (132) to correct nearsightedness / farsightedness, and a second vision correction adapter is positioned outside the lens system (130), for example, to the left of the first lens (131) to bend or tilt the first lens (131) and to the right of the second lens (132) to bend or tilt the second lens (132), in order to correct astigmatism and / or diplopia.

[0133] A vision correction adapter may be used to correct an observer's visual impairment in an optical system including at least one lens, such as one lens, two lenses (as shown in, for example, the optical system (110) of this disclosure), or three or more lenses. One or more surfaces of the vision correction adapter may be tilted to correct diplopia. One or more surfaces of the vision correction adapter may be curved to correct astigmatism. The surfaces of the vision correction adapter may be molded based on astigmatism and / or diplopia. The curved and / or tilted surfaces of the vision correction adapter may be positioned in contact with the surface of a lens in the optical system to bend and / or tilt the surface of the lens. The vision correction adapter may be positioned in contact with one lens to bend and / or tilt the lens. The vision correction adapter may be positioned in contact with two lenses (e.g., (131) and (132)) to (i) bend and / or tilt a first lens (131) and (ii) bend and / or tilt a second lens (132).

[0134] The lens within the optical system (110) can be bent or tilted by a vision correction adapter controlled by a controller (180). Any appropriate positional and / or orientational (or angular) control (e.g., mechanical, electrical, and / or similar) can be applied by the controller (180) and shift block (170) to control the position and orientation of the vision correction adapter with relatively high precision, for example, about 1 or 10 microns. Furthermore, the controlled lens can be flexible and durable. Thus, the shape and / or tilt angle of the lens can perfectly or substantially match the shape of the vision correction adapter. Therefore, in various embodiments, using a vision correction adapter in the optical system (110) allows for more accurate correction of visual impairment than without the vision correction adapter.

[0135] As described in this disclosure, the central region of a vision correction adapter for correcting visual impairment (e.g., (401), (411), (421), or (801)) may include an aperture. Thus, a light beam passing through the aperture (or central region) of the vision correction adapter is not obstructed or affected by the vision correction adapter within the optical system (110). In one example, the size of the aperture of the vision correction adapter is selected so that a light beam within a permissible angle ω of the optical system (110) (e.g., a subset of the light beam (124)) can pass through the aperture of the vision correction adapter without being affected by the circular band of the vision correction adapter.

[0136] Referring to Figures 4A, 4C, 4E, and 8A, the vision correction adapter (e.g., (401), (411), (421), or (801)) includes a band. In some examples, the vision correction adapter is a circular band or a non-circular band. The band can have any suitable shape. The band can be a closed structure, as shown in Figures 4A, 4C, and 4E. The band can be an open structure, such as a C-shaped structure, for noise truncation, for example. The vision correction adapter does not necessarily have a smooth or continuous contact surface. In one example, the vision correction adapter includes enough contact points to provide spacing between two lenses, to tilt a lens (e.g., a first lens (131) or a second lens (132)), and / or to bend (or curve) a lens (e.g., a first lens (131) or a second lens (132)). In one example, a vision correction adapter includes discrete points or discrete point contacts that contact the surface of the lens to tilt and / or bend the lens to correct astigmatism and / or diplopia. In another example, a vision correction adapter includes discrete point contacts that contact the surface of the lens or the surface of each lens to control the distance between the lenses to correct myopia / hyperopia.

[0137] In one embodiment, the vision correction adapter includes discrete point contacts arranged on a curved surface. The shape of the curved surface may be based on astigmatism (e.g., the degree and direction of astigmatism), and the discrete point contacts arranged on the curved surface may be configured to change the shape of a lens (e.g., a first lens (131) or a second lens (132)) to match the shape of the curved surface in order to correct astigmatism.

[0138] In one embodiment, the vision correction adapter includes discrete point contacts arranged on an inclined surface. The shape of the inclined surface may be based on diplopia (e.g., the degree and direction of diplopia), and the discrete point contacts arranged on the inclined surface may be configured to tilt a lens (e.g., a first lens (131) or a second lens (132)) to conform to the inclined surface in order to correct diplopia.

[0139] In one embodiment, the vision correction adapter includes discrete point contacts arranged on a curved surface. The shape of the curved surface can be based on astigmatism and diplopia. The discrete point contacts arranged on the curved surface may be configured to change the shape of a lens (e.g., a first lens (131) or a second lens (132)) and tilt the lens in order to correct astigmatism and diplopia.

[0140] In one embodiment, the vision correction adapter includes a first discrete point contact located on a curved surface and a second discrete point contact located on an inclined surface. The shape of the curved surface may be based on astigmatism. The shape of the inclined surface may be based on diplopia. The first discrete point contact located on the curved surface may be configured to change the shape of a lens (e.g., a flexible lens) (e.g., the first lens (131)) to correct astigmatism. The second discrete point contact located on the inclined surface may be configured to tilt another lens (e.g., a flexible lens) (e.g., the second lens (132)) to correct diplopia.

[0141] Depending on a mechanical reference such as a reference plane in the optical system, a vision correction adapter can be positioned outside the lens system (e.g., including two lenses) rather than between the two lenses, and can control the spacing, tilt, and / or curvature of the lenses relative to the other lens. The vision correction adapter can bend one or both lenses simultaneously. The vision correction adapter can tilt one or both lenses simultaneously with respect to the reference axis. The vision correction adapter can change the spacing between two lenses, or the spacing between one or two lenses and the reference surface. The vision correction adapter may be positioned between a lens in the lens system and another optical component (e.g., a display device (120)) and may be configured to change the spacing between the lens and the other optical component. The vision correction adapter may be positioned between two lenses in the lens system and may be configured to change the spacing between the two lenses in the lens system. For example, the vision correction adapter may be positioned outside the lens system, for example, between the lens system and the display device, so that the spacing between the lens system and the display device changes while the spacing between the two lenses remains unchanged. In one example, a vision correction adapter may be positioned within a lens system such that the distance between the two lenses changes, while the distance between one of the two lenses (e.g., (132)) and the display device (e.g., (120)) remains constant.

[0142] In some examples, the central region of the vision correction adapter (e.g., (401) or (801)) does not contain an aperture. An AR coating can be applied to the surface of the vision correction adapter to reduce undesirable reflections of the light beam, for example, to reduce or eliminate ghosting due to multiple reflections on the surface of the vision correction adapter.

[0143] In some embodiments, one or more lenses in the optical system (110) of the display system (100) may be flexible. Lenses can be made flexible by having a thickness below a threshold (e.g., mechanically thin) in order to impart flexibility. To improve durability and / or flexibility, lenses may be made from a flexible and / or durable lens material (e.g., (145) or (146)). The lens material may include polymers such as cyclic olefin copolymers (COC), PMMA, etc.

[0144] Figures 9A and 9B show examples of flexible lenses used in a display system (100) according to embodiments of the present disclosure. Figures 9A and 9B show portions of the display system (100) including a first lens (131) and a second lens (132). In the example shown in Figure 9A, the second lens (132) (e.g., a display lens) is flexible. The second lens (132) may be relatively thin. The second lens (132) may be an aspherical-to-aspherical lens. The first lens (131) may be a planar-to-spherical lens. The first lens (131) and the second lens (132) may be made from a polymer such as COC. The vision correction adapter may be positioned between the first lens (131) and the second lens (132), for example, in contact with the second lens (132) to tilt and / or bend the second lens (132) in order to correct a visual impairment.

[0145] In the example shown in Figure 9B, the first lens (131) (e.g., an eye lens) is flexible. The first lens (131) may be relatively thin. The first lens (131) may be an aspherical-to-aspherical lens. The second lens (132) may be a planar-to-spherical lens. The first lens (131) may be made from a polymer such as PMMA. The second lens (132) may be made from glass (e.g., BK7). The vision correction adapter may be positioned between the first lens (131) and the second lens (132), and may be positioned in contact with the first lens (131) to tilt and / or bend the first lens (131) to correct a visual impairment.

[0146] The birefringence of a flexible (e.g., bendable) lens can be controlled if the flexible lens is within the polarization system path. The birefringence of a flexible lens outside the polarization system path may not need to be controlled.

[0147] In one example, the vision correction adapter described herein may be used to correct vision impairments including myopia / hyperopia, astigmatism, and / or diplopia when the optical paths in the optical system are not folded, for example, when a light beam passes through the optical system (110) only once.

[0148] The display system (100) may be a component of an artificial reality system. The artificial reality system can adapt reality to an artificial reality in some way and then present the artificial reality to the user. The artificial reality may include, for example, virtual reality (VR), augmented reality (AR), mixed reality (MR), hybrid reality, or any combination and / or derivative thereof. The artificial reality content may include entirely generated content or content generated in combination with captured (e.g., real world) content. The artificial reality content may include video, audio, haptic feedback, or any combination thereof, any of which may be presented on a single channel or multiple channels (such as stereo video that produces a three-dimensional effect for the user). In some examples, the display system (100) may be applied to the playback of live or pre-recorded video.

[0149] In one embodiment, the “near-eye” display system may include an optical system (e.g., including one or more optical elements) and a display device that are positioned within a distance threshold of the user’s eye when the NED system (100) (e.g., an HMD or smart glasses) is used. Referring to Figure 5A, the distance D1 between the display device (120) and the area (151) may be less than or equal to the distance threshold. In one example, the distance D1 is between the display device (120) and the eye (60).

[0150] The display system (100) may be an NED system implemented in various forms, such as an HMD system, smart glasses, or a smartphone. In some examples, the artificial reality system is implemented as a standalone NED system. In some examples, the artificial reality system is implemented as an NED system connected to a host computer system, such as a server or console.

[0151] To achieve high-quality imaging, the reflective polarizer (139) needs to be of high quality, such as having high reflectivity in the blocking direction (e.g., high average reflectivity), high transmittance in the passing direction (e.g., high average transmittance), and relatively low surface roughness. Furthermore, an AR coating can be applied to any suitable surface within the optical system (110) to reduce or eliminate ghosting due to multiple reflections at various interfaces.

[0152] Polarized reflectance and refraction optical systems are a novel solution for virtual reality HMDs. A good VR optical system can accommodate multiple interpupillary distances and include a large pupillary volume (also called an eyebox) to allow eye rotation as the user scans across the field of view (FOV). In one example, the eyebox indicates the volume from which the eye receives an acceptable field of view of the image. The size and position of the eyebox may be related to several constraints, such as FOV and image quality. In one example, the eyebox indicates the range of eye positions at the eye relief distance, from which the image produced by the optical system (110) is seen. The eyebox can include eye movements, such as eye rotation and / or lateral movement.

[0153] In polarized reflective refractive optical systems such as display systems (100), a folded optical path (e.g., folded path (125)) can be used to achieve relatively high refractive power in a compact form factor. In the example shown in Figure 5A, the beam splitter (141) is a curved mirror that partially reflects and partially transmits light, and the reflective polarizer (139) can reflect or transmit light as a plane mirror depending on the polarization state of the light. The design freedom available in folded optical systems (e.g., optical system (110)) can bring advantages to HMD systems. These advantages may include high resolution achieved by reflective imaging, a wide FOV (e.g., by using low-aberration lenses), compact size, reduced weight, the ability to adjust focus, and the formation of a larger eyebox. The FOV can indicate the range of the observable world seen or detected by a photodetector (also called an optical sensor). In one example, the FOV is indicated by the solid angle from which the photodetector can detect or receive light. The optical system (110) shown in Figure 5A can be manufactured, for example, by controlling the curvature and surface finish of the first lens (131) and the second lens (132). Pancake optical systems (e.g., display system (100)) can provide a comfortable and immersive user experience.

[0154] The display system (100) can accommodate multiple interpupillary distances and may have a large pupillary volume to allow eye rotation when the user scans across the field of view. Interpupillary distance (IPD) is the distance between the centers of the pupils of the user's eyes. IPD can vary with respect to age, sex, etc. The display system (100) may be designed to take IPD dispersion into account so that the optical system (110) can accommodate various users with different IPDs. In one example, IPD varies between approximately 50 and 80 mm.

[0155] In one example, a display system (100) can adjust the diopters of lenses in a lens system (130) to match a prescription. In one example, the diopters indicate the distance to a virtual object. Increasing the diopters makes the object appear closer. Focusing can be achieved by changing the refractive power of the optical system. The refractive power of a folding mirror cavity (e.g., the optical cavity between a beam splitter (141) and a reflective polarizer (139)) can be changed by varying the cavity length (or gap) relative to the reference cavity length corresponding to the reference refractive power, as shown in Figures 5A to 5D.

[0156] Referring again to Figure 5A, the shift block (170) can be coupled to the optical system (110) and optionally to the display device (120) to apply appropriate spatial pixel shift adjustment to the virtual image. The controller (180) can be coupled to the optical system (110) and the shift block (170) to control the operation of the optical system (110) and the shift block (170).

[0157] The shift block (170) can apply spatial pixel shift adjustment mechanically or optically. The shift block (170) may include a mechanical shifter for applying spatial pixel shift adjustment. In some examples, the mechanical shifter can move the display device (120) to apply spatial pixel shift adjustment. In some examples, the mechanical shifter can move at least one optical element (e.g., a first lens (131) or a second lens (132)) to apply spatial pixel shift adjustment. Relatively small adjustments to the gap (197) can be amplified, for example, by a 3x due to the folding path (125) in the optical cavity.

[0158] The display system (100) may include other suitable mechanical, electrical, and optical components. For example, the display system (100) may include a frame (101) that can protect other components of the display system (100). In another example, the display system (100) may include a strap (not shown) for fitting the display system (100) to a user's head. In yet another example, the display system (100) may include communication components (not shown, e.g., communication software and hardware) for wireless communication with a network, host device, and / or other devices. In some examples, the display system (100) may include an optical combiner that can combine virtual content with a see-through reality environment.

[0159] Referring to Figure 5A, in some examples, the parameters of the display system (100) include the field of view (FOV), eye relief, lens track length, display size, and area (151) size. Eye relief (e.g., distance D3) can refer to the distance between the viewing position of the receiver (e.g., area (151)) and the lens system (130). In one example, the distance D3 between area (151) and the last optical component in the optical system (110) in front of area (151) (e.g., the first lens (131)) is 14 mm. Lens track length (e.g., distance D4) can refer to the distance between the display device (120) and the lens system (130). The distance D4 between the display device (120) and the first lens (131) is 15.9 mm. In the example shown in Figure 5A, the distance D4 from the display device (120) to the reflecting polarizer (139) is measured. In one example, D1 is equal to the sum of D3 and D4. In another example, the distance D4 from the display device (120) to the surface (137) is measured. The display size is indicated by a display image circle projected onto area (151) by the optical system (110), the display image circle having a radius of 18.9 mm. The size of area (151) (e.g., pupil size) can be 5 mm. The field of view (FOV) of the optical system (110) is 110°. The optical system (110) can be used with a suitable range of polychromatic wavelengths, such as visible wavelengths (e.g., 380-780 nm with a bandwidth of 400 nm) or polychromatic wavelengths close to green (e.g., 500 nm-540 nm with a bandwidth of 40 nm).

[0160] The parameter values ​​provided herein are for illustrative purposes only and are not intended to limit the scope of this disclosure. The optical paths, including ray diagrams, provided herein are for illustrative purposes only and are not intended to limit the scope of this disclosure. The drawings provided herein are for illustrative purposes only and are not to scale.

[0161] Figure 10 shows a flowchart illustrating an overview of a process (e.g., a vision correction process) (1000) according to some embodiments of the present disclosure. In one example, a display system or HMD system, such as a display system (100), includes an optical system (e.g., (110)) as described above. The optical system may be configured to direct a light beam from a display device or a real object to the eye of a user of the display system, as shown in Figure 5A. The optical system may include a vision correction adapter configured to correct a vision impairment.

[0162] In various examples, multiple users can use the display system. In one example, a user whose eye prescription information changes can use the display system. Therefore, the display system will be adapted to different eye conditions corresponding to different eye prescription information. In one embodiment, before the user uses the display system, a vision correction process (1000) may be performed to adjust the optical system based on at least the user's eye condition. The vision correction process (1000) may be configured to correct myopia / hyperopia, astigmatism, diplopia, etc. The process (1000) starts from step (S1001) and proceeds to step (S1010).

[0163] In step (S1010), visual acuity correction information for at least one of myopia, hyperopia, astigmatism, and diplopia can be obtained. The visual acuity correction information may include the user's eye prescription information.

[0164] In one embodiment, eye prescription information indicating (i) myopia or hyperopia and (ii) astigmatism may include spherical power (SPH), cylindrical power (CYL), and axis. The "Spherical Power (SPH)" parameter may indicate the refractive power of the lens used to correct the eye's myopia or hyperopia (in units of diopters (D) such as -1D or +2D). The "Spherical Power (SPH)" parameter may indicate the degree of myopia or hyperopia of the eye. An example of the "Spherical Power (SPH)" parameter is shown in relative diopters in Figure 5D. A "plus" (+) sign before the number may indicate that the eye is hyperopic and the lens focuses light. A "minus" (-) sign may indicate that the eye is myopic and the lens diverges light. The further the number in the eye prescription is from zero, the worse the visual acuity and the more visual correction (e.g., a stronger prescription) is required.

[0165] The relative diopter (e.g., the cylindrical power (CYL) parameter) can measure the degree of astigmatism in the eye and can be a negative or positive number, as shown by the relative diopter in Figure 6B. A larger cylindrical power (CYL) indicates greater astigmatism. The Axis parameter can be a number between 0° and 180°, indicating the direction of astigmatism.

[0166] In step (S1020), one or more of (i) the thickness T of the vision correction adapter and (ii) the shape of the vision correction adapter may be determined based on vision correction information. For example, eye prescription information is converted into mechanical parameters of the vision correction adapter.

[0167] Myopia or hyperopia, as indicated by diopters such as spherical (SPH) parameters (e.g., optical diopters), can be converted to the thickness T of a vision correction adapter, as explained with reference to Figures 4A-4B and 5A-5D.

[0168] The shape of the vision correction adapter may be determined based on astigmatism and / or diplopia.

[0169] Astigmatism, as indicated by the cylindrical diopter (or astigmatic diopter) such as the cylindrical power (CYL) parameter and Axis, can be translated into the shape of the vision correction adapter (e.g., the radius of curvature of the cylindrical surface), as explained with reference to Figures 4C-4H and 6A-6B, for example.

[0170] The diplopia (e.g., binocular diplopia) caused by the prism diopter can be translated into the shape of the vision correction adapter, such as the inclination angle (e.g., the inclination angle of the inclined surface of the vision correction adapter), as shown in Figures 3G, 4E-4H, and 8A-8B.

[0171] The cylindrical surface of a vision correction adapter configured to correct astigmatism and the inclined surface of a vision correction adapter configured to correct diplopia may be the same surface or different surfaces. If the cylindrical surface and the inclined surface are the same surface, the shape of the cylindrical surface may be based on astigmatism and diplopia.

[0172] In (S1030), the vision correction adapter may be manufactured based on one or more of the thickness and shape of the vision correction adapter. The central region of the vision correction adapter can be hollow. In one example, the vision correction adapter is made using 3D printing.

[0173] Then, process (1000) proceeds to step (S1099) and terminates.

[0174] Process (1000) can be appropriately adapted to various scenarios, and the steps within Process (1000) may be adjusted accordingly. One or more steps of Process (1000) can be adapted, omitted, repeated, and / or combined. Any appropriate order can be used to implement Process (1000). Further steps may be added.

[0175] In one embodiment, prior to (S1020), the relationship between the relative diopter and the thickness T of the vision correction adapter is determined (e.g., by empirically measuring or simulating), such as the look-up table in Figure 5D. The relationship between the relative diopter (e.g., cylindrical refractive power) and the radius of curvature of the vision correction adapter, such as the look-up table in Figure 6B, is determined (e.g., by empirically measuring or simulating). The relationship between the prism diopter and the inclination angle of the inclined surface of the vision correction adapter is determined (e.g., by empirically measuring or simulating), such as the look-up table in Figure 8B.

[0176] In one example, a manufactured vision correction adapter is configured to separate a first lens (e.g., (131)) and a second lens (e.g., (132)) in an optical system in order to correct at least one of myopia, hyperopia, astigmatism, and diplopia.

[0177] In one example, a standard adapter within a headset (e.g., including a display system (100)) is replaced with a manufactured vision correction adapter. The replacement and positioning of the manufactured vision correction adapter can be controlled with high precision via a controller (180) as described above.

[0178] In one example, the thickness of the vision correction adapter is determined based on whether the person is nearsighted or farsighted. The first and second lenses are spaced apart by the thickness of the vision correction adapter to correct the nearsightedness or farsightedness.

[0179] In one example, the first lens is flexible.

[0180] The shape of the vision correction adapter is determined based on the degree and direction of astigmatism. The manufactured vision correction adapter may be configured to modify the shape of the first lens to match the shape of the vision correction adapter in order to correct astigmatism.

[0181] In one example, the shape of the vision correction adapter is determined based on diplopia. The shape of the vision correction adapter can indicate the inclination angle and orientation of the inclined surface of the vision correction adapter. The manufactured vision correction adapter may be positioned to tilt the first lens according to the inclination angle and orientation of the inclined surface of the vision correction adapter in order to correct diplopia.

[0182] The embodiments of this disclosure may be used separately or combined in any order.

[0183] A computer or computer-readable medium can control various aspects of an HMD system incorporating a display system (e.g., (100)) including an optical system (e.g., (110)). Various aspects of the display system, including control of the movement and positioning of optical components (e.g., a first lens (131), a second lens (132), a display device (120), a vision correction adapter), may be implemented as computer software using computer-readable instructions or may be physically stored on one or more computer-readable media. For example, Figure 11 shows a computer system (1100) suitable for implementing a particular embodiment of the disclosed subject.

[0184] Computer software may be coded using any suitable machine language or computer language, which may be processed by assembly, compilation, linking, or similar mechanisms to create code containing instructions, which may be executed directly, or through interpretation, microcode execution, etc., by one or more computer central processing units (CPUs), graphics processing units (GPUs), etc.

[0185] The instructions may be executed on various types of computers or computer components, including, for example, personal computers, tablet computers, servers, smartphones, game consoles, and Internet of Things devices.

[0186] The components shown in Figure 11 with respect to the computer system (1100) are essentially illustrative and are not intended to imply any limitation on the scope of use or functionality of computer software implementing embodiments of the present disclosure. Furthermore, the configuration of the components should not be construed as having any dependencies or requirements relating to any one or combination of components shown in the exemplary embodiments of the computer system (1100).

[0187] The computer system (1100) may include certain human interface input devices. Such human interface input devices may respond to input from one or more human users through, for example, tactile input (keystrokes, swipes, data glove movements, etc.), voice input (voice, applause, etc.), visual input (gestures, etc.), and olfactory input (not shown). The human interface devices may also be used to capture certain media that are not necessarily directly related to conscious human input, such as sound (e.g., speech, music, ambient sounds), images (e.g., scanned images, photographic images taken from a still image camera), and video (e.g., two-dimensional video, three-dimensional video including stereoscopic video, etc.).

[0188] The input human interface device may include one or more (just one of each) of the following: keyboard (1101), mouse (1102), trackpad (1103), touchscreen (1110), data glove (not shown), joystick (1105), microphone (1106), scanner (1107), and camera (1108).

[0189] The computer system (1100) may also include certain human interface output devices. Such human interface output devices may stimulate the senses of one or more human users, for example, through tactile output, sound, light and smell / taste. Such human interface output devices may include tactile output devices (e.g., touchscreen (1110), data glove (not shown), or joystick (1105), although tactile feedback devices that do not function as input devices may also exist), audio output devices (e.g., speaker (1109), headphones (not shown)), touchscreen (1110) and visual output devices (e.g., CRT screen, LCD screen, plasma screen, OLED screen, each having or not having touchscreen input functionality, each having or not having tactile feedback functionality, some of which are capable of outputting two-dimensional visual output or output beyond three dimensions via means such as stereoscopic output, touchscreen (1110), virtual reality glasses (not shown), holographic displays and smoke tanks (not shown)), and printers (not shown).

[0190] The computer system (1100) may also include human-accessible storage devices and their associated media, such as optical media including CD / DVD ROM / RW (1120) and associated CD / DVD media (1121), thumb drives (1122), removable hard drives or solid-state drives (1123), legacy magnetic media such as tapes and floppy disks (not shown), and special ROM / ASIC / PLD-based devices such as security dongles (not shown).

[0191] Those skilled in the art will also understand that the term “computer-readable medium” as used in relation to the subject matter disclosed herein does not include transmission media, carrier waves, or other transient signals.

[0192] The computer system (1100) may also include an interface (1154) to one or more communication networks (1155). The networks may be, for example, wireless, wired, or optical. The networks may further be local, wide-area, metropolitan, automotive, and industrial, real-time, latency-tolerant, etc. Examples of networks include local area networks such as Ethernet, cellular networks including Wi-Fi, GSM, 3G, 4G, 5G, LTE, etc., wide-area digital networks for wired or wireless TV including cable TV, satellite TV, and terrestrial broadcast TV, and automotive and industrial networks including CANBus. Certain networks typically require an external network interface adapter connected to a specific general-purpose data port or peripheral bus (1149) (e.g., a USB port on the computer system (1100)), while others are generally integrated into the core of the computer system (1100) by connecting to a system bus, such as those described below (e.g., an Ethernet interface to a PC computer system or a cellular network interface to a smartphone computer system). Using any of these networks, the computer system (1100) can communicate with other entities. Such communication can be unidirectional, receive only (e.g., television broadcasting), unidirectional transmit only (e.g., from CANbus to a specific CANbus device), or bidirectional, for example, to other computer systems using local or wide-area digital networks. Several protocols and protocol stacks can be used for each of the aforementioned networks and network interfaces.

[0193] The aforementioned human interface device, human-accessible storage device, and network interface may be mounted on the core (1140) of the computer system (1100).

[0194] The core (1140) may include one or more central processing units (CPUs) (1141), graphics processing units (GPUs) (1042), dedicated programmable processing units in the form of field-programmable gate areas (FPGAs) (1043), hardware accelerators for specific tasks (1044), graphics adapters (1050), etc. These devices may be connected via a system bus (1148) along with read-only memory (ROM) (1045), random access memory (1046), internal mass storage such as internal user-inaccessible hard drives (1047), SSDs, etc. In some computer systems, the system bus (1148) may be accessible in the form of one or more physical plugs to enable expansion with additional CPUs, GPUs, etc. Peripheral devices may be connected directly to the core's system bus (1148) or via a peripheral bus (1149). For example, a touchscreen (1110) may be connected to the graphics adapter (1150). Peripheral bus architectures include PCI, USB, and others.

[0195] The CPU (1141), GPU (1142), FPGA (1143), and accelerator (1144) can execute certain instructions that, in combination, may constitute the aforementioned computer code. This computer code may be stored in ROM (1145) or RAM (1146). Transition data may be stored in RAM (1146), while persistent data may be stored in, for example, internal mass storage (1147). High-speed storage and retrieval of any of the memory devices may be enabled by using cache memory closely associated with one or more CPUs (1141), GPUs (1142), mass storage (1147), ROM (1145), RAM (1146), etc.

[0196] A computer-readable medium may contain computer code for performing various computer implementation operations. The medium and computer code may be specifically designed and configured for the purposes of this disclosure, or they may be of a type that is well known and available to those skilled in the computer software technology.

[0197] Without limitation, but as an example, a computer system (1100) having an architecture, in particular a core (1140), can provide functionality as a result of a processor (including a CPU, GPU, FPGA, accelerator, etc.) that runs software embodied in one or more tangible computer-readable media. Such computer-readable media may be user-accessible mass storage devices as described above, as well as media related to specific storage devices of the core (1140) of a non-transient nature, such as core internal mass storage (1147) or ROM (1145). Software implementing various embodiments of the present disclosure may be stored in such devices and executed by the core (1140). The computer-readable media may include one or more memory devices or chips, depending on the specific needs. The software may cause the core (1140) and, specifically, the processor (including a CPU, GPU, FPGA, etc.) within it to execute specific processes, or specific parts of specific processes, as described herein, including defining data structures stored in RAM (1146) and modifying such data structures according to processes defined by the software. In addition, or as an alternative, a computer system may provide functionality as a result of logic embodied in a circuit (e.g., an accelerator (1144)) in a hardwired or otherwise manner, which may operate in place of or with software to perform a particular process or a particular part of a particular process as described herein. Where necessary, references to software may include logic and vice versa. Where necessary, where “computer-readable medium” is mentioned, it may include a circuit (such as an integrated circuit (IC)) that stores the software to be executed, a circuit that implements the logic to be executed, or both. This disclosure includes any suitable combination of hard and software.

[0198] While this disclosure has described several exemplary embodiments, there are many variations, substitutions, and alternative equivalents that fall within the scope of this disclosure. Those skilled in the art will therefore understand that numerous systems and methods not expressly shown or described herein can be devised to embody the principles of this disclosure and thus fall within the spirit and scope of this disclosure. [Explanation of Symbols]

[0199] 60 Eye, 61 Image, 61' Image, 63 Lens, 64 Object, 65 Retina, 66 Image, 66' Image, 67 Near Object, 68 Distant Object, Retina, 69 Image, 69' Image, 70 Diverging Lens, 71 Converging Lens, 72 Cylindrical Lens, 80 Prism, 81 Base, 82 Top, 84 Light Beam, 85 Surface, 86 Surface, 100 Display System, NED System, 101 Frame, 110 Reflective and Refractive Optical System, 120 Display Device, 121 Boundary Ray, 122 Central Ray, 123 Boundary Ray, 124 Subset, 125 Folding Path, 130 Lens System, 131 First Lens, 132 Second Lens, 135 Surface, 136 Surface, 137 Surface, 138 Surface, 139 Reflective polarizer, 141 Beam splitter, 142 Quarter wave plate, 145 Light-transmitting member, 146 Light-transmitting member, 151 Area, 160 Optical axis, 170 Shift block, 180 Controller, 197 Gap, 199A Image plane, 199B Image plane, 199C Image plane, 401 Vision correction adapter, 402 Surface, 403 Surface, 404 Aperture, 411 Vision correction adapter, 412 Curved surface, 413 Surface, 421 Vision correction adapter, 422 Curved surface, 423 Interface, 424 Surface, 451 Prism, 501 Vision row, 502 Row, 503 Row, 504 Row, 505 Row, 506 Row, 507 Row, 508 Row, 509 Row, 510 Row, 511 Row, 601 Visual Acuity Row, 602 Row, 603 Row, 711 Ray, 712 Ray, 713 Ray, 714 Ray, 721 Pixel, 722 Virtual Image, 731 Pixel, 732 Virtual Image, 741 Pixel, 751 Virtual Image, 752 Virtual Image, 801 Prism, 811 Surface, 812 Surface, 1000 Visual Acuity Correction Process, 1044 Hardware Accelerator, 1045 Read-Only Memory, 1046 Random Access Memory, 1047 Internal Mass Storage, 1050 Graphics Adapter, 1100 Computer System, 1101 Keyboard, 1102 Mouse, 1103 Trackpad, 1105 Joystick, 1106 Microphone, 1107 Scanner, 1108 Camera, 1109 Speaker, 1110 Touchscreen, 1120 CD / DVD ROM / RW, 1121 Media, 1122Thumb drive, 1123 Removable hard drive or solid state drive, 1140 Core, 1141 CPU, 1142 GPU, 1143 FPGA, 1144 Accelerator, 1145 ROM, 1146 RAM, 1147 Core internal mass storage, 1148 System bus, 1149 Peripheral bus, 1150 Graphics adapter, 1154 Interface, 1155 Communication network

Claims

1. A first lens comprising a first light-transmitting member having a first surface and a second surface, A second lens comprising a second light-transmitting member having a third surface and a fourth surface, A vision correction adapter positioned between the first lens and the second lens, Equipped with, The first lens and the second lens are spaced apart by the thickness of the vision correction adapter. The thickness of the aforementioned vision correction adapter is selected to correct either nearsightedness or farsightedness. The central region of the aforementioned vision correction adapter includes an opening. Optical system.

2. The aforementioned vision correction adapter is a band between two parallel surfaces. The optical system according to claim 1.

3. The thickness of the aforementioned vision correction adapter is less than the threshold thickness for correcting myopia. The thickness of the vision correction adapter is greater than the threshold thickness for correcting hyperopia. The optical system according to claim 2.

4. A reflective polarizer disposed on one of the first surface and the second surface, which transmits light having a first linearly polarized state and reflects light having a second linearly polarized state perpendicular to the first linearly polarized state, A beam splitter disposed on either the third surface or the fourth surface, configured to partially transmit and partially reflect light incident on the beam splitter, wherein at least one of the first lens and the second lens has an optical cavity formed between the reflective polarizer and the beam splitter, Furthermore, The optical system is configured to direct light from the display device towards the viewing area, and the path of the light from the display device passes through the optical cavity multiple times. The optical system according to claim 1.

5. A first lens having flexibility, Vision correction adapter, Equipped with, The shape of the aforementioned vision correction adapter is based on the degree of astigmatism and the direction of the astigmatism. The vision correction adapter is configured to change the shape of the first lens to match the shape of the vision correction adapter in order to correct the astigmatism. Optical system.

6. The central region of the aforementioned vision correction adapter includes an opening, The aforementioned vision correction adapter includes a band and a curved surface, The shape of the curved surface is based on the degree and direction of the astigmatism, The curved surface is configured to change the shape of the first lens to conform to the shape of the curved surface. The optical system according to claim 5.

7. The aforementioned vision correction adapter includes discrete point contacts arranged on a curved surface, The shape of the curved surface is based on the degree and direction of the astigmatism, The discrete point contacts arranged on the curved surface are configured to change the shape of the first lens to match the shape of the curved surface. The optical system according to claim 5.

8. An optical system, A first lens comprising a first light-transmitting member having flexibility and having a first surface and a second surface, Equipped with a vision correction adapter, The central region of the aforementioned vision correction adapter includes an opening, The inclined surface of the vision correction adapter is inclined with respect to the optical axis of the optical system. The inclination angle and orientation of the inclined surface of the aforementioned vision correction adapter are based on diplopia, The vision correction adapter is configured to tilt the first lens according to the inclination angle and orientation of the inclined surface of the vision correction adapter in order to correct the double vision. Optical system.

9. The vision correction adapter includes a band and the inclined surface, The optical system according to claim 8.

10. A second lens comprising a second light-transmitting member having a third surface and a fourth surface, A reflective polarizer disposed on one of the first surface and the second surface, which transmits light having a first linearly polarized state and reflects light having a second linearly polarized state perpendicular to the first linearly polarized state, The beam splitter is disposed on either the third surface or the fourth surface, and is configured to partially transmit and partially reflect light incident on the beam splitter, wherein at least one of the first lens and the second lens has an optical cavity formed between the reflective polarizer and the beam splitter. The optical system is configured to direct light from the display device towards the viewing area, and the path of the light from the display device passes through the optical cavity multiple times. The optical system according to claim 8.

11. A first lens comprising a first light-transmitting member having a first surface and a second surface, A second lens comprising a second light-transmitting member having a third surface and a fourth surface, Vision correction adapter, Equipped with, At least one of the first lens and the second lens is flexible, The central region of the aforementioned vision correction adapter includes an opening, The vision correction adapter is configured to perform a plurality of actions: (i) changing the distance between the first lens and the second lens to correct one of myopia and hyperopia; (ii) changing the shape of at least one of the first lens or the second lens to match the shape of the vision correction adapter to correct astigmatism; and (iii) tilting at least one of the first lens or the second lens according to the shape of the vision correction adapter to correct diplopia. Optical system.

12. The vision correction adapter is configured to correct either myopia or hyperopia by changing the distance between the first lens and the second lens, and the thickness of the vision correction adapter is based on the degree of either myopia or hyperopia. The aforementioned vision correction adapter includes a band and a curved surface, The aforementioned vision correction adapter is (i) Modifying the shape of the first lens or the shape of the second lens to match the shape of the vision correction adapter in order to correct the astigmatism, (ii) tilting at least one of the first lens or the second lens according to the shape of the vision correction adapter in order to correct diplopia, Configured to perform at least one of the following: The optical system according to claim 11.

13. The vision correction adapter is configured to modify the shape of the first lens or the shape of the second lens to match the shape of the vision correction adapter in order to correct the astigmatism, The vision correction adapter is configured to tilt at least one of the first lens or the second lens according to the shape of the vision correction adapter in order to correct double vision. The optical system according to claim 11.

14. The first lens and the second lens are flexible, The aforementioned vision correction adapter includes a curved surface and an inclined surface, The shape of the curved surface is based on the degree and direction of the astigmatism. The curved surface is configured to change the shape of the first lens to match the shape of the curved surface in order to correct the astigmatism. The inclined surface is inclined with respect to the optical axis of the optical system. The inclination angle and orientation of the aforementioned inclined surface are based on diplopography, The vision correction adapter is configured to tilt the second lens according to the inclination angle and orientation of the inclined surface in order to correct the double vision. The optical system according to claim 11.

15. The first lens is flexible, The aforementioned vision correction adapter includes a curved surface, The shape of the curved surface is based on the degree and direction of the astigmatism. The curved surface is configured to change the shape of the first lens to match the shape of the curved surface in order to correct the astigmatism. The curved surface is inclined with respect to the optical axis of the optical system. The inclination angle and orientation of the curved surface are determined based on diplopography. The vision correction adapter is configured to tilt the first lens according to the inclination angle and orientation of the curved surface in order to correct the double vision. The optical system according to claim 11.

16. A method for manufacturing a vision correction adapter for an optical system, A step of obtaining vision correction information for at least one of myopia, hyperopia, astigmatism, or diplopia, Based on the aforementioned vision correction information, the steps include determining one or more of (i) the thickness of the vision correction adapter, or (ii) the shape of the vision correction adapter, A method comprising the step of manufacturing the vision correction adapter based on one or more determined thicknesses or shapes of the vision correction adapter, wherein the central region of the vision correction adapter is hollow.

17. The manufactured vision correction adapter is configured to separate the first lens and the second lens in the optical system in order to correct at least one of the myopia, hyperopia, astigmatism, or diplopia. The method according to claim 16.

18. The step of determining includes determining the thickness of the vision correction adapter based on myopia or hyperopia, The first lens and the second lens are spaced apart by the thickness of the vision correction adapter in order to correct the myopia or hyperopia. The method according to claim 17.

19. The first lens is flexible, The step of determining includes determining the shape of the vision correction adapter based on the degree and direction of the astigmatism, The manufactured vision correction adapter is positioned to modify the shape of the first lens to match the shape of the vision correction adapter in order to correct the astigmatism. The method according to claim 17.

20. The first lens is flexible, The step of determining includes determining the shape of the vision correction adapter based on the diplopia, wherein the shape of the vision correction adapter indicates the inclination angle and orientation of the inclined surface of the vision correction adapter. The manufactured vision correction adapter is arranged such that the first lens is tilted according to the tilt angle and orientation of the inclined surface of the vision correction adapter in order to correct the double vision. The method according to claim 17.

Images