CN118435086A - Optical dimming lens and manufacturing method thereof - Google Patents

Abstract

A lens is provided. The lens includes a first material layer including a first lens material having a first birefringence, a first density, and a first impact resistance. The lens further includes a second material layer coupled with the first material layer, and the second material layer includes a second lens material having a second birefringence, a second density, and a second impact resistance. The first birefringence is lower than the second birefringence, the first density is lower than the second density, and the second impact resistance is stronger than the first impact resistance.

Description

Optical dimming lens and manufacturing method thereof

Related Applications

This application claims priority to U.S. Provisional Application No. 63/292,471, filed on December 22, 2021, and priority to U.S. Provisional Patent Application No. 63/353,562, filed on June 18, 2022.

Technical Field

The present disclosure relates generally to optical devices, and more particularly to an optical dimming lens and a method for manufacturing the same.

Background technique

Artificial reality devices, such as head-mounted displays (“Head-Mounted Display, HMD”) or heads-up displays (“Heads-Up Display, HUD”) devices, have wide applications in various fields including aviation, engineering design, medical surgical practice, and video games. Artificial reality devices can display virtual objects or combine images of real objects with virtual objects, such as in augmented reality (“Augmented Reality, AR”) applications, virtual reality (“Virtual Reality, VR”) applications, and/or mixed reality (“Mixed Reality, MR”) applications. When the artificial reality device is implemented for AR and/or MR applications, the artificial reality device can be at least partially transparent from the user's perspective, allowing the user to view the surrounding real-world environment. When the artificial reality device is implemented for VR applications, the artificial reality device can be opaque, allowing the user to be roughly immersed in the VR imagery provided via the artificial reality device.

Summary of the invention

According to a first aspect of the present disclosure, a lens is provided. The lens comprises a first material layer, the first material layer comprises a first lens material, the first lens material has a first birefringence, a first density and a first impact resistance. The lens further comprises a second material layer, the second material layer is coupled to the first material layer, and the second material layer comprises a second lens material, the second lens material has a second birefringence, a second density and a second impact resistance. The first birefringence is lower than the second birefringence, the first density is lower than the second density, and the second impact resistance is stronger than the first impact resistance.

In some embodiments, the lens has an inner side facing the user's eye and an outer side facing the real-world environment, the first material layer is located at the outer side of the lens, and the second material layer is located at the inner side of the lens.

In some embodiments, the first material layer is configured to have a customized optical power for providing vision correction, and the second material layer is configured to have zero optical power or an optical power less than a predetermined value.

In some embodiments, the first lens material includes at least one of a cyclic olefin copolymer or a cyclic olefin polymer, and the second lens material includes at least one of polycarbonate, polymethyl methacrylate, polyethylene, polypropylene, or polyurethane.

In some embodiments, the first material layer has a retardation value less than 100 nm.

In some embodiments, the lens further comprises an optically transparent adhesive layer disposed between the first material layer and the second material layer.

In some embodiments, the center thickness of the first material layer is in the range of 1.0 mm to 1.5 mm, the center thickness of the second material layer is in the range of 0.2 mm to 0.7 mm, and the optically transparent adhesive layer has a uniform thickness in the range of 0.01 mm to 0.2 mm.

In some embodiments, the lens further includes a dimming element disposed between the first material layer and the second material layer, and the dimming element includes at least one of a non-electrically tunable dimming material or an electrically tunable dimming material.

In some embodiments, the second material layer includes a group of two second material layers, and the lens further includes a dimming element disposed between the two second material layers.

In some embodiments, the lens further includes a dimming material doped into at least one of the first material layer or the second material layer.

According to another aspect of the present disclosure, a method is provided. The method includes providing a first material layer, the first material layer including a first lens material, the first lens material having a first birefringence, a first density, and a first impact resistance. The method also includes arranging a dimming element at the first material layer. The method also includes arranging a second material layer at the dimming element. The second material layer includes a second lens material, the second lens material having a second birefringence, a second density, and a second impact resistance. The first birefringence is lower than the second birefringence, the first density is lower than the second density, and the second impact resistance is stronger than the first impact resistance.

In some embodiments, the stack of the first material layer, the dimming element and the second material layer forms a lens; the lens has an inner side facing the user's eyes and an outer side facing the real-world environment; the first material layer is located at the outer side of the lens, and the second material layer is located at the inner side of the lens.

In some embodiments, the first material layer is configured to have a customized optical power for providing vision correction, and the second material layer is configured to have zero optical power or an optical power less than a predetermined value.

In some embodiments, the first lens material includes at least one of a cyclic olefin copolymer or a cyclic olefin polymer, and the second lens material includes at least one of polycarbonate, polymethyl methacrylate, polyethylene, polypropylene, or polyurethane.

In some embodiments, the first material layer has a retardation value less than 100 nm.

In some embodiments, disposing the light dimming element at the first material layer includes laminating the light dimming element to the concave surface of the first material layer via an optically clear adhesive layer.

According to another aspect of the present disclosure, a method is provided. The method includes providing a first material layer, the first material layer including a first lens material, the first lens material having a first birefringence, a first density, and a first impact resistance. The method includes setting a dimming element into a second material layer. The second material layer includes a second lens material, the second lens material having a second birefringence, a second density, and a second impact resistance. The method includes setting the second material layer at the first material layer. The first birefringence is lower than the second birefringence, the first density is lower than the second density, and the second impact resistance is stronger than the first impact resistance.

In some embodiments, disposing the dimming element in the second material layer includes encapsulating the dimming element in the second material layer.

In some embodiments, disposing the second material layer at the first material layer includes laminating the second material layer to the concave surface of the first material layer via an optically clear adhesive layer.

In some embodiments, the stack of the first material layer, the dimming element and the second material layer forms a lens; the lens has an inner side facing the user's eyes and an outer side facing the real-world environment; the first material layer is located at the outer side of the lens, and the second material layer is located at the inner side of the lens.

Those skilled in the art can understand other aspects of the present disclosure according to the specification, claims and drawings of the present disclosure.The foregoing general description and the following detailed description are exemplary and explanatory only and do not limit the claims.

It will be understood that any feature described herein as being suitable for incorporation into one or more aspects or one or more embodiments of the present disclosure is intended to be generalizable to any and all aspects and embodiments of the present disclosure. Other aspects of the present disclosure can be understood by those skilled in the art based on the specification, claims and drawings of the present disclosure. The above general description and the following detailed description are exemplary and explanatory only and do not limit the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are provided for illustrative purposes according to various disclosed embodiments and are not intended to limit the scope of the present disclosure. In the drawings:

FIG1A shows a schematic diagram of an artificial reality device according to an embodiment of the present disclosure;

FIG. 1B schematically illustrates a cross-sectional view of one half of the artificial reality device shown in FIG. 1A according to an embodiment of the present disclosure;

FIG. 1C illustrates an image perceived by a user of the artificial reality device when the artificial reality device shown in FIG. 1A operates in an augmented reality (“AR”) mode or in a mixed reality (“MR”) mode according to an embodiment of the present disclosure;

FIG. 1D illustrates an image perceived by a user of the artificial reality device when the artificial reality device shown in FIG. 1A operates in virtual reality (“VR”) according to an embodiment of the present disclosure;

FIG2A shows a schematic diagram of a dimming lens according to an embodiment of the present disclosure;

FIG2B shows a schematic diagram of a dimming lens according to an embodiment of the present disclosure;

FIG2C shows a schematic diagram of a dimming lens according to an embodiment of the present disclosure;

FIG2D shows a schematic diagram of a dimming lens according to an embodiment of the present disclosure;

FIG2E shows a schematic diagram of a dimming lens according to an embodiment of the present disclosure;

3A and 3B are schematic diagrams showing a display system including a dimming lens according to an embodiment of the present disclosure;

FIG3C shows a schematic diagram of a display system including a dimming lens according to an embodiment of the present disclosure;

FIG3D shows a schematic diagram of a display system including a dimming lens according to an embodiment of the present disclosure;

4A and 4B are schematic diagrams showing dimming elements that may be included in a dimming lens according to an embodiment of the present disclosure;

FIG4C shows a schematic diagram of a dimming element that may be included in a dimming lens according to an embodiment of the present disclosure;

5A and 5B are schematic diagrams showing dimming elements that may be included in a dimming lens according to an embodiment of the present disclosure;

FIG5C shows a schematic diagram of a dimming element that may be included in a dimming lens according to an embodiment of the present disclosure;

6A and 6B are schematic diagrams showing dimming elements that may be included in a dimming lens according to an embodiment of the present disclosure;

FIG6C shows a schematic diagram of a dimming element that may be included in a dimming lens according to an embodiment of the present disclosure;

FIG. 7A is a flow chart showing a method for manufacturing a dimming lens according to an embodiment of the present disclosure; and

FIG. 7B is a flow chart illustrating a method for manufacturing a dimming lens according to an embodiment of the present disclosure.

Detailed ways

Embodiments consistent with the present disclosure will be described with reference to the accompanying drawings, which are merely examples for illustrative purposes and are not intended to limit the scope of the present disclosure. Wherever possible, the same reference numerals are used in all drawings to represent the same or similar components, and detailed descriptions of these components may be omitted.

In addition, in the present disclosure, the disclosed embodiments and the features of the disclosed embodiments may be combined. The described embodiments are some embodiments of the embodiments of the present disclosure but not all embodiments. Based on the disclosed embodiments, a person of ordinary skill in the art may derive other embodiments consistent with the present disclosure. For example, modifications, adaptations, substitutions, additions or other changes may be made based on the disclosed embodiments. Such changes of the disclosed embodiments are still within the scope of the present disclosure. Therefore, the present disclosure is not limited to the disclosed embodiments. Rather, the scope of the present disclosure is defined by the appended claims.

As used herein, the terms "couple", "coupled", or "coupling", etc. may include optical coupling, mechanical coupling, electrical coupling, electromagnetic coupling, or any combination thereof. "Optical coupling" between two optical elements refers to a configuration in which the two optical elements are arranged in an optical series and the light output from one optical element can be directly or indirectly received by the other optical element. Optical series refers to the optical positioning of multiple optical elements in an optical path so that the light output from one optical element can be transmitted, reflected, diffracted, converted, modified, or otherwise processed or manipulated by one or more other optical elements. In some embodiments, the order in which the multiple optical elements are arranged may or may not affect the overall output of the multiple optical elements. Coupling may be direct coupling or indirect coupling (e.g., coupling through an intermediate element).

The phrase "at least one of A or B" may encompass all combinations of A and B, such as only A, only B, or A and B. Similarly, the phrase "at least one of A, B, or C" may encompass all combinations of A, B, and C, such as only A, only B, only C, A and B, A and C, B and C, or A and B and C. The phrase "A and/or B" may be interpreted in a manner similar to the phrase "at least one of A or B." For example, the phrase "A and/or B" may encompass all combinations of A and B, such as only A, only B, or A and B. Similarly, the meaning of the phrase "A, B, and/or C" is similar to the meaning of the phrase "at least one of A, B, or C." For example, the phrase "A, B, and/or C" may encompass all combinations of A, B, and C, such as only A, only B, only C, A and B, A and C, B and C, or A and B and C.

When a first element is described as being "attached", "provided", "formed", "bonded", "installed", "fixed", "connected", "combined", "recorded" or "set" to, on, at, or at least partially in a second element, the first element may be "attached", "provided", "formed", "bonded", "installed", "fixed", "connected", "combined", "recorded" or "set" to, on, at, or at least partially in a second element, using any suitable mechanical or non-mechanical means (such as, depositing, coating, etching, combining, gluing, screwing, press fit, snap fit, clamping, etc.). In addition, the first element may be in direct contact with the second element, or there may be an intermediate element between the first element and the second element. The first element may be disposed on any suitable side of the second element (such as left, right, front, back, top or bottom).

When a first element is shown or described as being set or arranged "on" a second element, the term "on..." is only used to indicate the relative orientation of an example between the first element and the second element. The description may be based on the reference coordinate system shown in the figure, or may be based on the current view or example configuration shown in the figure. For example, when describing the view shown in the figure, the first element may be described as being set "on" a second element. It should be understood that the term "on..." may not necessarily imply that the first element is located above the second element in the vertical direction of gravity. For example, when the assembly of the first element and the second element is rotated 180 degrees, the first element may be "below" the second element (or the second element may be "on" the first element). Therefore, it should be understood that when the drawings show that the first element is "on" a second element, the configuration is merely an illustrative example. The first element may be set or arranged in any suitable orientation relative to the second element (e.g., located above or above the second element, located below or below the second element, located to the left of the second element, located to the right of the second element, located behind the second element, located in front of the second element, etc.).

When a first element is described as being disposed "on" a second element, the first element may be disposed on the second element directly or indirectly. The first element being directly disposed on the second element means that no additional elements are disposed between the first element and the second element. The first element being indirectly disposed on the second element means that one or more additional elements are disposed between the first element and the second element.

The term "processor" as used herein may encompass any suitable processor, such as a central processing unit (CPU), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or any combination thereof. Other processors not listed above may also be used. The processor may be implemented as software, hardware, firmware, or any combination thereof.

The term "controller" may encompass any suitable electronic circuit, software, or processor configured to generate control signals for controlling a device, circuit, optical element, etc. A "controller" may be implemented as software, hardware, firmware, or any combination thereof. For example, a controller may include a processor, or may be included as part of a processor.

The term "non-transitory computer-readable medium" may encompass any suitable medium for storing, transferring, transmitting, broadcasting or transmitting data, signals or information. For example, non-transitory computer-readable media may include memory, hard disk, magnetic disk, optical disk, magnetic tape, etc. The memory may include read-only memory (ROM), random access memory (RAM), flash memory, etc.

The terms "film", "layer", "coating" or "sheet" may include rigid or flexible, self-supporting or free-standing films, layers, coatings or sheets, which may be disposed on a supporting substrate or between substrates. The terms "film", "layer", "coating" and "sheet" may be interchangeable. The term "film plane" refers to a plane in a film, layer, coating or sheet that is perpendicular to the thickness direction of the film, layer, coating or sheet. The film plane may be a plane in the volume of the film, layer, coating or sheet, or may be a surface plane of the film, layer, coating or sheet.

The term "orthogonal" as used in "orthogonal polarizations", or the term "orthogonally" as used in "orthogonally polarized", means that the inner product of the two vectors representing the two polarizations is approximately zero. For example, two lights or two beams with orthogonal polarizations (or two orthogonally polarized lights or beams) can be two linearly polarized lights (or beams) with two orthogonal polarization directions (e.g., the x-axis direction and the y-axis direction in a Cartesian coordinate system), or two circularly polarized lights with opposite handedness (e.g., left-handed circularly polarized light and right-handed circularly polarized light).

The wavelength ranges, spectra or bands mentioned in the present disclosure are for illustrative purposes. The disclosed optical devices, systems, elements, assemblies and methods can be applied to the visible band as well as other bands, such as the ultraviolet (UV) band, the infrared (IR) band or a combination thereof. The terms "substantially" or "mainly" used to modify the optical response function (such as, describing the transmission, reflection, diffraction or blocking of the processing of light, etc.) mean that most (including all) of the light is transmitted, reflected, diffracted or blocked, etc. Most of the light can be a predetermined percentage (greater than 50%) of the total light, such as 100%, 98%, 90%, 85%, 80%, etc., which can be determined based on the specific application needs.

Dimming lenses have been used to increase the dynamic range of artificial reality devices. In order to meet product specifications, optical dimming lenses must meet certain properties or performances, such as compactness and light weight, strong enough impact resistance to pass government agency testing, and perspective quality with negligible birefringence issues. It is often challenging to meet all of these requirements required for artificial reality devices. The present disclosure provides a dimming lens that provides light weight, strong impact resistance, and low birefringence.

FIG. 1A shows a schematic diagram of an artificial reality device 100 according to an embodiment of the present disclosure. In some embodiments, the artificial reality device 100 can generate VR, AR and/or MR content, such as images, videos, audio, or a combination thereof, for a user. In some embodiments, the artificial reality device 100 may be smart glasses. In one embodiment, the artificial reality device 100 may be a near-eye display (“Near-Eye Display, NED”). In one embodiment, the artificial reality device 100 may be a head-up display. In some embodiments, the artificial reality device 100 may be glasses, goggles, a helmet, a head-mounted display, or some other type of eye-mounted device (eyewear). In some embodiments, the artificial reality device 100 may be configured to be worn on the user's head (e.g., in the form of eyepieces (spectacles) or glasses (eyeglasses) as shown in FIG. 1A), or included as part of a helmet worn by a user. In some embodiments, the artificial reality device 100 may be configured to be placed near one or both eyes of the user, at a fixed position in front of one or both eyes, rather than mounted to the user's head. In some embodiments, the artificial reality device 100 may be in the form of glasses that provide vision correction. In some embodiments, the artificial reality device 100 may be in the form of plano-eyeglasses that do not provide vision correction. In some embodiments, the artificial reality device 100 may be in the form of sunglasses that protect the user's eyes from bright sunlight. In some embodiments, the artificial reality device 100 may be in the form of protective glasses that protect the user's eyes. In some embodiments, the artificial reality device 100 may be in the form of a night vision device or infrared goggles that enhance the user's vision at night. The artificial reality device 100 may be implemented in other forms.

For purposes of discussion, FIG. 1A shows that an artificial reality device 100 includes a frame 105 configured to be mounted to a user's head, and a left-eye display system 110L and a right-eye display system 110R mounted to the frame 105. FIG. 1B is a cross-sectional view of one half of the artificial reality device 100 shown in FIG. 1A according to an embodiment of the present disclosure. For purposes of illustration, FIG. 1B shows a cross-sectional view associated with the left-eye display system 110L. The frame 105 is merely an example structure in which various components of the artificial reality device 100 may be mounted. Other suitable types of fixtures may be used in place of or in combination with the frame 105.

In some embodiments, each of the left eye display system 110L and the right eye display system 110R may include an image display component 120 configured to generate image light representing a computer-generated virtual image and direct the image light to an eyebox area 160, where an eye 159 may be positioned to receive the image light. The eyebox area 160 may include a plurality of exit pupils 157. The exit pupils 157 may be locations where eye pupils 158 of a user's eye 159 may be positioned in the eyebox area 160 to receive the image light. For example, in some embodiments, the image display component 120 may include: a light source configured to output image light representing a virtual image; and an image combiner configured to direct the image light received from the light source to the eyebox area 160. In some embodiments, the image combiner can also emit ambient light (or real-world light) 142 from the real-world environment toward the eyebox area 160, thereby combining the image light and the real-world light 142, and guiding both the image light and the real-world light toward the eyebox area 160. Therefore, the eye 159 can observe the virtual scene optically combined with the real-world scene. The image display component 120 can be any suitable image display component, and the image combiner can be any suitable image combiner, such as a light guide coupled with an in-coupling element and an out-coupling element, a holographic optical element ("Holographic Optical Element, HOE"), etc. To simplify the illustration, the details of the image display component 120 are not shown in FIG. 1B.

In some embodiments, as shown in FIG. 1B , each of the left eye display system 110L and the right eye display system 110R may include a dimming lens 122 formed of two lens materials of different material properties. The dimming lens 122 can provide light weight, high impact resistance, and low birefringence. The image display assembly 120 may include an outer side facing the real world environment and an inner side facing the eye frame area 160. The dimming lens 122 may be disposed at the outer side of the image display assembly 120. Note that although these elements are shown as having a flat surface for illustrative purposes, in some embodiments, at least one of the image display assembly 120 or the dimming lens 122 (e.g., each) may include a curved surface. In some embodiments, the dimming lens 122 may be formed integrally with the image display assembly 120, or may be a separate element stacked with the image display assembly 120.

In some embodiments, the dimming lens 122 may be configured to dim ambient light (or real-world light) 142 from the real-world environment toward the eyebox area 160. Ambient light 142 from the real-world environment outside the left-eye display system 110L and the right-eye display system 110R may be incident on the dimming lens 122 before the ambient light 142 is incident on the image display component 120. The dimming lens 122 may reduce the transmittance of the ambient light 142 based on a suitable dimming mechanism (such as polarization, absorption, scattering and/or diffusion), or block the ambient light 142 from being incident on the image display component 120.

In some embodiments, the dimming lens 122 may be a global dimming lens configured to have uniform light transmittance across the entire aperture of the dimming lens 122. In other words, the dimming lens 122 may be configured to uniformly dim or attenuate the real-world light 142 across the entire aperture of the dimming lens 122. In some embodiments, the dimming lens 122 may be a regional dimming lens or a local dimming lens configured to provide different light transmittances at different regions (or zones) of the aperture of the dimming lens 122. The light transmittances of the real-world light 142 at various regions or portions of the dimming lens 122 may be individually or independently controllable.

In some embodiments, the transmittance or dimming effect of the dimming lens 122 on the real-world light 142 may be fixed. In some embodiments, the transmittance or dimming effect of the dimming lens 122 on the real-world light 142 may be adjusted by a suitable external field. In some embodiments, the transmittance or dimming effect of the dimming lens 122 may be adjusted by adjusting the electric field. For example, the dimming lens 122 may include: a dimming material with an electrically tunable transmittance (referred to as an electrically tunable dimming material for discussion purposes); and one or more electrode layers, the one or more electrode layers being configured to be electrically coupled to a power source (the power source may provide a voltage to the electrode layers) to provide a tunable electric field in the dimming material. Examples of electrically tunable dimming materials may include guest-host liquid crystal (“LC”) materials (e.g., a host LC doped with a guest dye (e.g., a dichroic dye)), polymer-stabilized cholesteric LC materials, suspended particles, electrochromic materials, electrophoretic materials, and the like.

In some embodiments, the transmittance or dimming effect of the dimming lens 122 may be adjustable by a suitable external field other than an electric field (e.g., a magnetic field, temperature, or light, etc.). For example, in some embodiments, the dimming lens 122 may include a dimming material having a non-electrically tunable transmittance (referred to as a non-electrically tunable dimming material for discussion purposes). The light transmittance of the non-electrically tunable dimming material may be tuned via methods other than a tuning voltage, such as by a change in ambient light or temperature, etc. Examples of non-electrically tunable dimming materials may include photochromic materials, photodichroic materials, thermochromic materials, etc. In some embodiments, the dimming material may include both electrically tunable dimming materials and non-electrically tunable dimming materials to achieve a desired dimming effect.

In some embodiments, the dimming lens 122 may be an ophthalmic lens with a prescription (e.g., single vision, bifocal, trifocal, or progressive) to provide vision correction for the user's vision. For example, the dimming lens 122 may be configured to change the ambient light 142 while transmitting the ambient light 142 to provide vision correction for the user's vision. In some embodiments, the dimming lens 122 may be a plano lens that does not provide vision correction. For example, in some embodiments, the dimming lens 122 may be configured as a flat plate or a curved plate with zero optical power for the ambient light 142.

In some embodiments, as shown in FIG1B , the artificial reality device 100 may further include an object tracking component 190 (e.g., an eye tracking component and/or a facial tracking component). The object tracking component 190 may include an infrared (“IR”) light source 191, a deflection element 192 (such as a grating), and an optical sensor 193 (such as a camera), the light source being configured to emit IR light to illuminate the eye 159 and/or the face. The deflection element 192 may deflect (e.g., diffract) the IR light reflected by the eye 159 toward the optical sensor 193. The optical sensor 193 may generate a tracking signal associated with the eye 159 based on the IR light deflected by the deflection element 192. The tracking signal may be an image of the eye 159. The artificial reality device 100 may include a controller (not shown) that may control various optical elements in the left eye display system 110L and/or the object tracking component 190.

The artificial reality device 100 may be configured to operate in VR mode, AR mode, or MR mode. The artificial reality device 100 may be configured to switch between operating in VR mode, AR mode, and/or MR mode in indoor and outdoor environments. In some embodiments, when the artificial reality device 100 operates in AR or MR mode, the dimming lens 122 may operate in a transparent (clear) state or an intermediate state, and from the user's perspective, the left eye display system 110L and the right eye display system 110R may be completely transparent or partially transparent, thereby providing the user with a view of the surrounding real world environment. In some embodiments, when the artificial reality device 100 operates in VR mode, the dimming lens 122 may operate in an opaque state, and the left eye display system 110L and the right eye display system 110R may be opaque to block light from the real world environment, so that the user can be immersed in a VR image based on a computer-generated image.

FIG1C shows an image perceived by a user of an artificial reality device 100 operating in an AR mode or in an MR mode according to an embodiment of the present disclosure. FIG1D shows an image perceived by a user of an artificial reality device 100 operating in a VR mode according to an embodiment of the present disclosure. For the purpose of discussion, FIG1C and FIG1D show images viewed through a right-eye display system 110R. As shown in FIG1C , when the artificial reality device 100 operates in an AR mode or an MR mode, the user can perceive a virtual scene or virtual image 102 superimposed on a real-world scene 104. As shown in FIG1D , when the artificial reality device 100 operates in a VR mode, the user can perceive the virtual scene 102 but cannot perceive the real-world scene 104.

FIG2A shows a schematic diagram of a dimming lens (or dimming device) 200 according to an embodiment of the present disclosure. The dimming lens 200 may be an embodiment of the dimming lens 122 shown in FIG1B . The dimming lens 200 may include a first material layer 131 and a second material layer 132 coupled to the first material layer 131. The first material layer 131 may be located at the outer side of the dimming lens 200 facing the real world environment and receiving the ambient light 142. The second material layer 132 may be located at the inner side of the dimming lens 200 facing the user's eye 159. Although the first material layer 131 and the second material layer 132 are shown as having curved surfaces, in some embodiments, at least one of the first material layer 131 or the second material layer 132 may have one or two surfaces that are flat in the thickness direction (e.g., the z-axis direction of FIG2A ).

The first material layer 131 may be manufactured based on a first lens material, and the second material layer 132 may be manufactured based on a second lens material different from the first lens material. In some embodiments, the lens first material and the second lens material may be optically transparent within the operating wavelength range (e.g., visible spectrum) of the dimming lens 200. In some embodiments, the density of the first lens material may be lower than the density of the second lens material. In some embodiments, within the operating wavelength range (e.g., visible spectrum) of the dimming lens 200, the birefringence of the first lens material may be lower than the birefringence of the second lens material. In some embodiments, the first lens material included in the first material layer 131 may have a density equal to or less than a predetermined density and a birefringence equal to or less than a predetermined birefringence. Therefore, the second lens material may have a density greater than a predetermined density and a birefringence greater than a predetermined birefringence. For example, the density of the first lens material may be about 1.0 g/cm ³ or less, and the birefringence of the first lens material may be about 10 ^-5 or less. That is, the predetermined density may be, for example, 1.0 g/cm ³ , 1.05 g/cm ³ , 1.1 g/cm ³ , etc. The predetermined birefringence may be 10 ^-5 , 2×10 ^-5 , 5×10 ^-5 , etc. The birefringence of the first lens material may be at least 1/10 of the birefringence of the second lens material.

In some embodiments, the impact resistance of the second lens material may be higher than the impact resistance of the first lens material. Impact resistance (or impact strength) is related to the resistance of a material to impact, and impact resistance can be measured as the energy absorbed by a standardized sample breaking under a standardized impact (unit: J or ft-lbs). The impact resistance (or impact strength) can be calculated by dividing the impact energy by the thickness of the sample. In some embodiments, the second lens material may have an impact resistance equal to or greater than a predetermined impact resistance threshold. Therefore, the first lens material may have an impact resistance less than a predetermined impact resistance threshold. The impact resistance of the second lens material may be at least 10 times the impact resistance of the first lens material.

For example, the notched impact strength of the second lens material can be about 0.7 ft-lbs/in or more, about 0.8 ft-lbs/in or more, about 0.9 ft-lbs/in or more, about 1.0 ft-lbs/in or more, about 1.5 ft-lbs/in or more, about 2.0 ft-lbs/in or more, about 3.0 ft-lbs/in or more, about 4.0 ft-lbs/in or more, about 5.0 ft-lbs/in or more, about 10.0 ft-lbs/in or more, about 15.0 ft-lbs/in or more, etc. The second lens material can comply with at least one of the U.S. Food and Drug Administration ("FDA") drop ball test or equivalent impact test standards for lenses in Europe and Asia. For example, to pass the FDA's drop ball test for a lens, a 5/8 inch steel ball weighing approximately 0.56 ounces is dropped from a height of 50 inches onto a 5/8 inch diameter circle at the geometric center of the lens, and the lens must not break.

Examples of first lens materials may include cycloolefin copolymer ("Cyclic Olefin Copolymer, COC") or cycloolefin polymer ("Cyclic Olefin Polymer, COP"), etc. COC and COP have optical properties similar to those of glass, such as high transparency, low birefringence, high Abbe number, and high heat resistance. Examples of second lens materials may include polycarbonate ("Polycarbonate, PC"), polymethyl methacrylate ("Polymethyl methacrylate, PMMA"), polyethylene ("Polyethylene, PE"), polyurethane or polypropylene ("Polypropylene, PP"), etc. For example, the impact resistance of PC is 10 times that of traditional plastics or glass. The following table shows some properties of example materials that can be used as the first lens material and the second lens material. The present disclosure is not limited to these materials.

surface

Material Density (g/cm ³ ) Birefringence Notched Impact Strength (ft-lbs/in) COC 1.0 Less than 10 ^-5 0.69 COP 1.08 Less than 10 ^-5 0.56 PC 1.20 ~10 ^-4 12.0 to 16.0

In some embodiments, the dimming lens 200 can be an ophthalmic lens with a prescription (e.g., single vision, bifocal, trifocal, or progressive) to provide vision correction for the user's vision. As shown in FIG. 2A, the first material layer 131 can be configured to have a customized non-zero optical power for correcting the user's vision, and the second material layer 132 can be configured to have a substantially low optical power or zero optical power (e.g., the second material layer 132 can be a flat plate or a curved plate with a uniform thickness and substantially zero optical power). For example, the absolute value of the optical power provided by the second material layer 132 can be lower than the absolute value of the optical power provided by the first material layer 131. The radius of curvature of the inner surface of the first material layer 131 can be substantially the same as the radius of curvature of the outer surface of the second material layer 132. For discussion purposes, FIG. 2A shows that the first material layer 131 is used as a concave-convex lens configured for hyperopia correction. In some embodiments, the first material layer 131 may be configured for another type of vision correction, for example, the first material layer 131 may be used as a convex-concave lens configured for myopia correction, etc. In some embodiments, the dimming lens 200 may not provide vision correction, and the first material layer 131 and the second material layer 132 may both be configured to have zero optical power, for example, the first material layer 131 and the second material layer 132 may both be flat plates or curved plates with zero optical power.

The first material layer 131 manufactured based on a first lens material having a relatively low density and a low birefringence may have a light weight and good image quality. In addition, the second material layer 132 manufactured based on a second lens material having a relatively high impact resistance may provide good safety for the user's eyes 159. When the second material layer 132 is configured to have zero optical power, the relatively high birefringence of the second lens material included in the second material layer 132 may not reduce the image performance of the dimming lens 200.

In some embodiments, the first material layer 131 may be configured to be thicker than the second material layer 132. For example, the thickness of the first material layer 131 may be in the range of 0.1 mm to 1.1 mm, in the range of 0.1 mm to 1.0 mm, in the range of 0.1 mm to 0.9 mm, in the range of 0.1 mm to 0.8 mm, in the range of 0.1 mm to 0.7 mm, in the range of 0.1 mm to 0.6 mm, in the range of 0.1 mm to 0.5 mm, in the range of 0.5 mm to 1.1 mm, in the range of 0.6 mm to 1.1 mm, in the range of 0.7 mm to 1.1 mm, or in the range of 0.8 mm to 1.1 mm, etc. In some embodiments, the thickness of the second material layer 132 may be in the range of 0.01 mm to 0.5 mm, in the range of 0.01 mm to 0.4 mm, in the range of 0.01 mm to 0.3 mm, in the range of 0.01 mm to 0.2 mm, or in the range of 0.01 mm to 0.1 mm, etc. In some embodiments, the center thickness of the first material layer 131 may be in the range of 1.0 mm to 1.5 mm. The "center thickness" may be the thickness measured at the geometric center point (or optical center point) of the layer. In some embodiments, the center thickness of the second material layer 132 may be in the range of 0.2 mm to 0.7 mm. In some embodiments, the first material layer 131 may have a retardation value of less than 100 nm within an operating wavelength range (e.g., a visible wavelength range).

In some embodiments, the first material layer 131 and the second material layer 132 may be manufactured via suitable processes, such as diamond turning, molding, casting, three-dimensional (“3D”) printing, or a combination thereof. In some embodiments, the first material layer 131 and the second material layer 132 may be laminated together (e.g., via an optically transparent adhesive layer), wherein the second material layer 132 is laminated on the inner side (e.g., concave surface) of the first material layer 131 facing the user's eye 159. For example, the first material layer 131 and the second material layer 132 may be laminated and bonded together by a suitable optically transparent adhesive. In some embodiments, the optically transparent adhesive layer may have a uniform thickness over the aperture of the dimming lens 200. The thickness of the optically transparent adhesive layer may be in the range of 0.01 mm to 0.2 mm. The dimming lens 200 may include a dimming material 136 for dimming the ambient light 142, and the dimming material 136 may be doped into at least one of the first material layer 131 or the second material layer 132. For the purpose of illustration, FIG2A shows that the dimming material 136 is doped into the second material layer 132. In some embodiments, although not shown, the dimming material 136 may be doped into the first material layer 131. The dimming material 136 may include a non-electrically tunable dimming material, such as a photochromic material, a photodichroic material, a thermochromic material, etc. The dimming material 136 may provide a tunable dimming effect for the ambient light 142 (e.g., according to the temperature or brightness of the ambient light 142), or may provide a non-tunable fixed dimming effect.

A conventional lens manufactured based on a single first lens material layer (e.g., COC or COP, etc.) can provide a relatively light weight and a relatively low birefringence, but relatively low impact resistance, while a conventional lens manufactured based on a single second lens material layer (e.g., PC, PMMA, PE, or PP, etc.) can provide a relatively high impact resistance, but a relatively heavy weight and a relatively high birefringence. The dimming lens 200 including a first material layer 131 manufactured with a first lens material and a second material layer 132 manufactured with a second lens material can be configured to provide a balance between weight, birefringence, and impact resistance. For example, compared to a conventional lens manufactured based on a single first lens material layer (e.g., COC or COP, etc.) or a single second lens material layer (e.g., PC, PMMA, PE, or PP, etc.), the dimming lens 200 can simultaneously provide low weight, low birefringence, and high impact resistance.

FIG2B shows a schematic diagram of a dimming lens (or dimming device) 210 according to an embodiment of the present disclosure. The dimming lens 210 may be an embodiment of the dimming lens 122 shown in FIG1B . The dimming lens 210 may include a first material layer 131 manufactured based on a first lens material and a second material layer 132 manufactured based on a second lens material. In the embodiment shown in FIG2B , the dimming lens 210 may also include a dimming material layer 138 disposed between the first material layer 131 and the second material layer 132. In some embodiments, the dimming material 138 may include a non-electrically tunable dimming material, such as a photochromic material, a photodichroic material, a thermochromic material, etc. The dimming material 138 may provide a tunable dimming effect (e.g., according to the temperature or brightness of the ambient light 142) or a non-tunable fixed dimming effect for the ambient light 142.

FIG2C shows a schematic diagram of a dimming lens (or dimming device) 230 according to an embodiment of the present disclosure. The dimming lens 230 may be an embodiment of the dimming lens 122 shown in FIG1B . The dimming lens 230 may include a first material layer 131 manufactured based on a first lens material, two second material layers 132a and 132b manufactured based on a second lens material (these two second material layers may be referred to as a second material layer and a third material layer, respectively), and a dimming material layer 138. A stack formed by the dimming material layer 138 and the second material layers 132a and 132b may be disposed at the inner side of the first material layer 131 facing the eye 159. For example, the stack formed by the dimming material layer 138 and the second material layers 132a and 132b may be laminated to the inner side (e.g., concave surface) of the first material layer 131 facing the user's eye 159. The second material layer 132a may be disposed between the first material layer 131 and the dimming material layer 138. The dimming material layer 138 may be disposed between the second material layer 132a and the second material layer 132b. The first material layer 131 may be configured to have a non-zero optical power for vision correction, and the second material layers 132a and 132b may be configured to have substantially low optical power or zero optical power (e.g., the second material layer 132a or 132b may be a flat plate or a curved plate with a uniform thickness and substantially zero optical power). For example, the absolute value of the optical power provided by the second material layers 132a and 132b may be lower than the absolute value of the optical power provided by the first material layer 131.

FIG2D shows a schematic diagram of a dimming lens (or dimming device) 240 according to an embodiment of the present disclosure. The dimming lens 240 may be an embodiment of the dimming lens 122 shown in FIG1B. The dimming lens 240 may include a first material layer 131, a second material layer 132, and a dimming unit (or dimming element) 166 disposed between the first material layer 131 and the second material layer 132. The dimming unit 166 may include a dimming material layer 207 and at least one electrode layer. For illustrative purposes, FIG2D shows that the first electrode layer 209-1 and the second electrode layer 209-2 are disposed on opposite sides of the dimming material layer 207, respectively. The electrode layers 209-1 and 209-2 may be optically transparent within the operating wavelength range (e.g., visible spectrum) of the dimming lens 240. In some embodiments, the electrode layers 209-1 and 209-2 may also be optically transparent in the IR spectrum.

In some embodiments, each of the electrode layers 209-1 and 209-2 may include a continuous planar electrode. In some embodiments, one of the electrode layers 209-1 and 209-2 may include a continuous planar electrode, and the other electrode layer of the electrode layers 209-1 and 209-2 may include a patterned electrode formed by a plurality of discrete, separated sub-electrodes. For example, in some embodiments, the patterned electrode may include a first sub-electrode surrounded by a second sub-electrode. In some embodiments, the patterned electrode may include a pixelated sub-electrode array. In some embodiments, each of the electrode layers 209-1 and 209-2 may include a patterned electrode. For example, in some embodiments, each patterned electrode may include a plurality of separated stripe electrodes arranged in parallel, and the stripe electrodes in each patterned electrode may be arranged to extend in parallel in different directions (e.g., orthogonal directions). In some embodiments, the electrode layers 209-1 and 209-2 may include a conductive material, which is indium tin oxide ("Indium Tin Oxide, ITO"), aluminum-doped zinc oxide ("Al-doped ZincOxide, AZO"), graphene, poly (3,4-ethylenedioxythiophene): poly (styrene-sulfonate) ("Poly (3,4-ethylenedioxythiophene): Poly (Styrene-sulfonate), PEDOT: PSS"), carbon nanotubes or silver nanowires, or a combination thereof.

In some embodiments, the two electrode layers 209-1 and 209-2 may be disposed at the inner surface of the first material layer 131 and the outer surface of the second material layer 132, respectively, via a suitable method (e.g., coating or deposition, etc.). In some embodiments, in order to reduce surface reflection at the interface between the electrode layer 209-1 and the inner surface of the first material layer 131, a refractive index matching layer (not shown) may be disposed between the electrode layer 209-1 and the inner surface of the first material layer 131. In some embodiments, in order to reduce surface reflection at the interface between the electrode layer 209-2 and the outer surface of the second material layer 132, a refractive index matching layer (not shown) may be disposed between the electrode layer 209-2 and the outer surface of the second material layer 132.

The dimming material layer 207 may include a dimming material having an electrically tunable transmittance (referred to as an electrically tunable dimming material for the purpose of discussion). As controlled by a controller, the light transmittance of the electrically tunable dimming material may be tunable when the electric field applied to the dimming material changes. Examples of electrically tunable dimming materials may include guest-host liquid crystal ("LC") materials (e.g., host LC doped with a guest dye (e.g., a dichroic dye)), polymer-stabilized cholesteric LC materials, suspended particles, electrochromic materials, electrophoretic materials, and the like. In some embodiments, the dimming material layer 207 may also include a dimming material having a non-electrically tunable transmittance (referred to as a non-electrically tunable dimming material for the purpose of discussion). The light transmittance of the non-electrically tunable dimming material may be adjusted via methods other than adjusting the voltage, for example, by changing the ambient light or temperature, and the like. Examples of non-electrically tunable dimming materials may include photochromic materials, photodichroic materials, thermochromic materials, and the like. Examples of dimming devices 166 may include guest-host liquid crystal ("LC") dimming devices, polymer-stabilized cholesteric LC dimming devices, suspended particle devices, electrochromic dimming devices, electrophoretic dimming devices, electroplating dimming devices, photochromic dimming devices, photodichroic dimming devices, dimming devices including electrically tunable dimming material layers and non-electrically tunable dimming material layers, and the like.

In some embodiments, the dimming material layer 207 may be configured to have a uniform thickness over the aperture of the dimming device 166 (e.g., in the x-axis direction in FIG. 2D ). In some embodiments, the dimming material layer 207 may be configured to have a non-uniform thickness over the aperture of the dimming device 166. For example, the dimming material layer 207 may have a greater thickness at the center of the aperture than at the periphery of the aperture. For the purpose of discussion, FIG. 2D shows that the dimming material layer 207 is configured to have two curved surfaces, and the electrode layers 209-1 and 209-2 are curved electrode layers. In some embodiments, the dimming material layer 207 may be configured to have a curved surface and a flat surface, for example, one of the electrode layers 209-1 and 209-2 may be a curved electrode layer, and the other electrode layer may be a flat electrode layer. In some embodiments, the dimming material layer 207 may be configured to have two flat surfaces, for example, each of the electrode layers 209-1 and 209-2 may be a flat electrode layer.

The electrode layers 209-1 and 209-2 may be electrically coupled to the power source 175. The controller 215 may be connected to the power source 175, and may control the output (e.g., voltage output or current output) of the power source 175 to the electrode layers 209-1 and 209-2. Thus, the controller 215 may control the electric field (e.g., the amplitude and/or direction of the electric field) applied to the dimming material layer 207 via the electrode layers 209-1 and 209-2, thereby controlling the operating state of the dimming device 166. In some embodiments, the controller 215 may control the dimming device 166 so that the dimming device 166 can switch between operating in a transparent state and operating in a dark state (also referred to as an opaque state). Thus, the dimming lens 240 may be able to switch between operating in a transparent state and operating in a dark state.

In some embodiments, the dimming device 166 operating in the dark state can be configured to substantially block visible real-world light 142, for example, having a light transmittance of about 0.01% (or having an optical density of 4.0). The light transmittance of the dimming device 166 operating in the dark state can be referred to as a minimum transmittance of the dimming device 166. The dimming device 166 operating in the transparent state can be configured to provide a predetermined transmittance greater than the minimum transmittance to the real-world light 142. In some embodiments, the predetermined transmittance can be in a range from about 30% to about 50%, for example, 30%, 35%, 40%, 45%, 50%, 30% to 40%, 40% to 50%, or any other sub-range within the range of 30% to 50%. In some embodiments, the predetermined transmittance can be in the range of about 30% to about 60% (e.g., 30%, 35%, 40%, 45%, 50%, 55%, 60%, 30% to 40%, 40% to 50%, 50% to 60%, or any other sub-range within the range of 30% to 60%), in the range of about 30% to about 70% (e.g., 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 30% to 40%, 40% to 50%, 50% to 60%, 60% to 70%, or any other sub-range within the range of 30% to 70%), in the range of about 30% to about 80% (e.g., 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 30% to 40%, 40% to 50%, 50% to 60%, 60% to 70%, or any other sub-range within the range of 30% to 70%), %, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 30% to 40%, 40% to 50%, 50% to 60%, 60% to 70%, 70% to 80%, or any other sub-range within the range of 30% to 80%), or in the range of about 30% to about 90% (30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 30% to 40%, 40% to 50%, 50% to 60%, 60% to 70%, 70% to 80%, 80% to 90%, or any other sub-range within the range of 30% to 90%), etc. Thus, the user can perceive the virtual scene superimposed with the real world scene. For the purpose of discussion, the predetermined transmittance of the dimming device 166 operating in the transparent state may be referred to as the maximum transmittance of the dimming device 166. In some embodiments, in addition to the transparent state and the dark state, the controller 215 may also control the dimming device 166 to operate in an intermediate state. Therefore, the dimming lens 240 may operate in an intermediate state. The dimming device 166 operating in the intermediate state may provide a transmittance greater than the minimum transmittance in the dark state and less than the maximum transmittance in the transparent state. By controlling the transmittance of the dimming device 166, the transmittance of the dimming lens 240 may be controlled. Therefore, the transmittance of the see-through view observed through the dimming lens 240 may be dynamically adjusted.

In some embodiments, the dimming device 166 may be a global dimming device configured to have a uniform light transmittance across the entire aperture of the dimming device 166. In other words, the dimming device 166 may be configured to uniformly dim or attenuate the real-world light 142 across the entire aperture of the dimming device 166. Therefore, the dimming lens 240 may be a global dimming lens. In some embodiments, the dimming device 166 may be a regional dimming device or a local dimming device configured to provide different light transmittances at different regions (or zones) of the aperture of the dimming device 166. The light transmittance of the real-world light 142 at each region or portion may be individually or independently controllable. In some embodiments, each region (or zone) of the aperture of the dimming device 166 may include one or more pixelated dimming elements. The light transmittance at each pixelated dimming element may be individually or independently controllable. In some embodiments, the size of each pixelated dimming element may be greater than 1 mm. Therefore, the dimming lens 240 may be a regional dimming lens or a local dimming lens.

For illustration purposes, the dimming effect of the dimming lens 240 shown in Figure 2D is shown to be tunable by an external electric field applied to the dimming material layer 207. Other mechanisms may also be implemented to adjust the dimming effect based on the properties of the dimming material.

FIG2E schematically shows a schematic diagram of a dimming lens 250 according to an embodiment of the present disclosure. The dimming lens 250 may include a first material layer 131, a dimming unit 166, and two second material layers 132a and 132b. The dimming unit 166 may be disposed between the two second material layers 132a and 132b. For example, the dimming unit 166 may be encapsulated into a second lens material so that substantially the entire dimming unit 166 is surrounded by the second lens material. As described above, the material included in the two second material layers 132a and 132b may be substantially the same as the second lens material included in the second material layer 132. The configuration may be similar to the configuration shown in FIG2C except that the dimming effect is provided by the electrically tunable dimming unit 166.

In various embodiments as shown in FIG. 2D and FIG. 2E , in addition to the electrically tunable dimming cell 166, the dimming lens 240 or 250 may further include a separate non-electrically tunable dimming material layer disposed at a suitable position (such as, at the outer surface of the first material layer 131 in the embodiment shown in FIG. 2D , between the first material layer 131 and the active dimming cell 166, or between the first material layer 131 and the second material layer 132a in the embodiment shown in FIG. 2E ). In some embodiments, the dimming material layer 138 shown in FIG. 2C may also be replaced by the electrically tunable dimming cell 166.

Referring to Figures 2A to 2E, in some embodiments, the dimming lens 200, 210, 230, 240, or 250 may be a global dimming lens configured to have a uniform light transmittance across the entire aperture of the dimming lens. In other words, the dimming lens 200, 210, 230, 240, or 250 may be configured to uniformly dim or attenuate the real-world light 142 across the entire aperture of the dimming lens. In some embodiments, the dimming lens 200, 210, 230, 240, or 250 may be a regional dimming lens or a local dimming lens configured to provide different light transmittances at different regions (or zones) of the aperture of the dimming lens. The light transmittance of the real-world light 142 at each region or portion of the dimming lens may be individually or independently controllable. In some embodiments, each region (or zone) of the aperture of the dimming lens may include one or more pixelated dimming elements. The light transmittance at each pixelated dimming element may be individually or independently controllable.

FIG3A shows an x-z cross-sectional view of a display system 300 according to an embodiment of the present disclosure. The display system 300 may be implemented in an artificial reality device for AR applications, VR applications, and/or MR applications (such as the artificial reality device 100 shown in FIGS. 1A to 1D ). For example, the display system 300 may be an embodiment of the display system 110L or 110R shown in FIGS. 1A and 1B . As shown in FIG3A , the display system 300 may include a light guide display component 320. The light guide display component 320 may be included in the image display component 120 shown in FIG1B , or may be implemented as the image display component 120 shown in FIG1B . The display system 300 may also include a dimming lens 312. The dimming lens 312 may be any embodiment of a dimming lens disclosed herein, such as the dimming lens 200 shown in FIG2A , the dimming lens 210 shown in FIG2B , the dimming lens 230 shown in FIG2C , the dimming lens 240 shown in FIG2D , or the dimming lens 250 shown in FIG2E . For discussion purposes, FIG. 3A illustrates that the dimming lens 312 has the same or similar configuration as the dimming lens 240 illustrated in FIG. 2D .

The dimming lens 312 may be disposed at an outer side of the light guide display assembly 320 facing the real world environment. The light guide display assembly 320 may include a light source assembly 305. The light guide 310 may be coupled with an incoupling element 335 and an outcoupling element 345. The light guide 310 may include a first surface 310-1 and a second surface 310-2. The light source assembly 305 may be configured to output image light 330 representing a virtual image 350 (e.g., including a virtual object 302). The light guide 310 coupled with the incoupling element 335 and the outcoupling element 345 may be configured to guide the image light 330 to one or more exit pupils 157 in the eyebox region 160 of the display system 300. For example, the incoupling element 335 may couple the image light 330 into the light guide 310 as incoupling image light 332. The incoupling image light 332 may propagate from the incoupling element 335 toward the outcoupling element 345 within the light guide 310 by total internal reflection. The outcoupling element 345 can couple the incoupled image light 332 incident on different portions of the outcoupling element 345 out of the light guide 310 as a plurality of output image lights 334 propagating toward the eyebox region 160, thereby replicating the image light 330 outside the light guide 320. Thus, the eye 159 located at the exit pupil 157 can perceive the virtual image generated by the light source assembly 305. In some embodiments, the light guide 310 coupled with the incoupling element 335 and the outcoupling element 345 can also transmit the real-world light 142 toward the eyebox region 160. Thus, the eye 159 located at the exit pupil 157 can perceive the virtual image optically combined with the real-world scene. The light guide 310 coupled with the incoupling element 335 and the outcoupling element 345 can be used as an image combiner that optically combines a virtual scene with a real-world scene, for example, a light guide image combiner.

In some embodiments, the dimming lens 312 may be formed separately and disposed at (e.g., fixed to) a surface (e.g., first surface 310-1) of the light guide 310 that faces the real world environment. In some embodiments, the first dimming lens 312 may be integrally formed as a part of the light guide 310. In some embodiments, the area of the dimming lens 312 may be greater than or equal to the area of the outcoupling element 345. The dimming lens 312 may be disposed on a side of the outcoupling element 345 that faces the real world environment. In some embodiments, as shown in FIG. 3A , the dimming lens 312 may be disposed at the first surface 310-1 of the light guide 310, and the outcoupling element 345 may be disposed at the second surface 310-2 of the light guide 310. In some embodiments, the outcoupling element 345 may also be disposed at the first surface 310-1 and between the dimming lens 312 and the light guide 310. It should be noted that although FIG. 3A shows the light guide 310 as having a flat surface, the light guide 310 may have a curved surface, or the entire light guide 310 may be curved (eg, having a curvature that matches the curvature of the second material layer 132 ).

The controller 215 (not shown) can be coupled to the dimming lens 312 and/or various elements in the light guide display assembly 320 to control their operation. The controller 215 can control the operating state of the dimming lens 312 to dynamically adjust the transmittance of the real-world light 142, so that the artificial reality device including the display system 300 switches between operating in VR mode and operating in an AR device or between operating in a VR device and operating in an MR device. For example, when the controller 215 controls the dimming lens 312 to operate in a dark state, the virtual reality device including the display system 300 can be configured to operate in VR mode. When the controller 215 controls the dimming lens 312 to operate in a transparent state or an intermediate state, the virtual reality device including the display system 300 can be configured to operate in AR mode or MR mode. In some embodiments, the dimming lens 312 can be configured to dynamically attenuate the real-world light 142 according to the brightness of the real-world environment, thereby adjusting the brightness of the perspective view. For example, when an artificial reality device including display system 300 operates in AR mode or MR mode, dimming lens 312 can be configured to adjust the brightness of the see-through view to alleviate the brightness difference between the see-through view and the virtual image perceived by the user.

In some embodiments, the dimming lens 312 may be a global dimmer. For example, when the artificial reality device including the display system 300 operates in an AR mode or in an MR mode, the display system 300 may provide a uniform contrast ratio of a perspective view to a virtual image across the aperture of the dimming lens 312. In some embodiments, the dimming lens 312 may be a regional dimmer or a local dimmer. For example, when the artificial reality device including the display system 300 operates in an AR mode or in an MR mode, the display system 300 may provide different contrast ratios of a perspective view to a virtual image at different regions (or portions, zones) of the aperture of the dimming lens 312.

For the purpose of discussion, FIG3A shows that the controller 215 controls the dimming lens 312 to operate in a dark state, and therefore, the virtual reality device including the display system 300 operates in VR mode. The dimming lens 312 can substantially block the real-world light 142 from being transmitted through the light guide 310 toward the eyebox area 160. Therefore, the eye 159 located at the exit pupil 157 can only perceive the image 355 of the virtual object 302.

For the purpose of discussion, FIG3B shows that the controller 215 controls the dimming lens 312 to operate in a transparent state or an intermediate state, so that the virtual reality device including the display system 300 operates in an AR mode or in an MR mode. The dimming lens 312 can transmit the real-world light 142 toward one or more exit pupils 157 in the eyebox area 160. Therefore, the eye 159 located at the exit pupil 157 can perceive an image 375 in which the virtual scene (e.g., the virtual object 302) is superimposed with the real-world scene (e.g., the image 304 of the real-world object 274). In some embodiments, the dimming lens 312 can be an ophthalmic lens configured to change the real-world light 142 while transmitting the real-world light 142 to provide vision correction for the user's vision.

3A and 3B show that the light guide display assembly 320 and the dimming lens 312 are separate components arranged in a stacked configuration. In some embodiments, the light guide display assembly 320 can be embedded in the dimming lens 312. FIG. 3C shows an x-z cross-sectional view of a display system 360 according to an embodiment of the present disclosure. The display system 360 can be implemented in an artificial reality device (such as the artificial reality device 100 shown in FIGS. 1A to 1D) for AR applications, VR applications, and/or MR applications. For example, the display system 360 can be an embodiment of the display system 110L or 110R shown in FIGS. 1A and 1B. The display system 360 may include elements, structures, and/or functions that are the same or similar to the elements, structures, and/or functions included in the display system 300 shown in FIGS. 3A and 3B. The description of the same or similar elements, structures, and/or functions can refer to the above description presented in conjunction with FIGS. 3A and 3B.

As shown in FIG3C , the display system 360 may include a light guide display assembly 320 and a dimming lens 312. In the embodiment shown in FIG3C , the light guide display assembly 320 and the dimming lens 312 may not be arranged in a stacked configuration. Instead, the light guide display assembly 320 may be at least partially embedded in the second material layer 132 of the dimming lens 312. The light guide display assembly 320 may not be embedded in the dimming device 166 and the first material layer 131, and therefore, the output image light 334 of the light guide 310 may not be affected by the dimming device 166. In some embodiments, the second material layer 132 of the dimming lens 312 may change the output image light 334 while transmitting the output image light 334 toward one or more exit pupils 157 in the eyebox area 160 to provide vision correction for the user's vision. In some embodiments, although not shown, the dimming lens 312 may include a non-electrically tunable dimming material doped into the first material layer 131, and the light guide display component 320 may be at least partially embedded in the second material layer 132 of the dimming lens 312. As shown in FIG3C , in some embodiments, at least a portion of the light guide 310 on which the outcoupling element 345 is mounted may be embedded in the second material layer 132 of the dimming lens 312. In some embodiments, the light guide 310 may be a curved light guide having a curvature that matches the curvature of the second material layer 132.

FIG3D shows an x-z cross-sectional view of a display system 380 according to an embodiment of the present disclosure. The display system 380 may be implemented in an artificial reality device (such as the artificial reality device 100 shown in FIGS. 1A to 1D ) for AR applications, VR applications, and/or MR applications. For example, the display system 380 may be an embodiment of the display system 110L or 110R shown in FIGS. 1A and 1B . The display system 380 may include elements, structures, and/or functions that are the same or similar to the elements, structures, and/or functions included in the display system 300 shown in FIGS. 3A and 3B or the display system 360 shown in FIG. 3C . The description of the same or similar elements, structures, and/or functions may refer to the above description presented in conjunction with FIGS. 3A and 3B or FIG. 3C .

As shown in FIG3D , the display system 380 may include a holographic optical element (“HOE”) display assembly 390 and a dimming lens 312. The HOE display assembly 390 may include a light source assembly 305 and an HOE image combiner 385. The light source assembly 305 may be configured to output image light 330 representing a virtual image 350 (e.g., including a virtual object 302) toward the HOE image combiner 385. The HOE image combiner 385 may focus the image light 330 to one or more points at one or more exit pupils 157 within the eyebox region 160. In some embodiments, the dimming lens 312 may be formed separately and disposed at (e.g., fixed to) a surface (e.g., a first surface 385-1) of the HOE image combiner 385 that faces the real-world environment. It should be noted that although Figure 3D shows the HOE image combiner 385 having a flat surface, the HOE image combiner 385 may have a curved surface, or the entire HOE image combiner 385 may be curved (e.g., having a curvature that matches the curvature of the second material layer 132).

The controller 215 (not shown) can be communicatively coupled with the dimming lens 312 and/or various elements in the HOE display assembly 390 to control their operation. For example, the controller 215 can control the operating state of the dimming lens 312 to dynamically adjust the transmittance of the real-world light 142, so that the artificial reality device including the display system 380 switches between operating in VR mode and operating as an AR device or between operating in a VR device and operating in an MR device. When configured for AR applications or MR applications, the HOE image combiner 385 can combine the image light 338 focused by the HOE image combiner 385 with the real-world light 142, and direct the two lights toward the eyebox area 160.

In some embodiments, although not shown, the HOE image combiner 385 may be at least partially embedded in the second material layer 132 of the dimming lens 312. The HOE image combiner 385 may not be embedded in the dimming device 166 and the first material layer 131, and therefore, the output image light 338 of the HOE image combiner 385 may not be affected by the dimming device 166.

The display system 300 shown in Figures 3A and 3B, the display system 360 shown in Figure 3C, and the display system 380 shown in Figure 3D are for illustrative purposes to explain the implementation of the disclosed dimming lens in a display system included in an artificial reality device. The disclosed dimming lens can also be implemented in smart glasses or other suitable eye-mounted devices. The light guide display assembly 320 shown in Figures 3A to 3C is for illustrative purposes and is an example of the image display assembly 120 shown in Figure 1B. In some embodiments, the display system may include another suitable image display assembly in addition to the light guide display assembly 320 and the HOE display assembly 390, and the display assembly may include another suitable image combiner in addition to the light guide image combiner and the HOE image combiner.

In the following, an exemplary dimming element that can be implemented in the disclosed dimming lens will be explained. The dimming element can attenuate the input light via a suitable dimming mechanism such as polarization, absorption and/or scattering. Figures 4A and 4B show an x-z cross-sectional view of a dimming element 400 according to an embodiment of the present disclosure. The dimming element 400 can be an embodiment of the dimming element 166 shown in Figure 2D or Figure 2E. The dimming element 400 can be a guest-host LC dimming device. As shown in Figure 4A, the dimming element 400 can include electrode layers (or conductive layers) 209-1 and 209-2 and a dimming material layer 207 disposed between the electrode layer 209-1 and the electrode layer 209-2. Each electrode layer 209-1 or 209-2 can be provided with an alignment layer 404. The dimming material layer 207 can be disposed between the alignment layers 404. The alignment layer 404 provides alignment for the molecules included in the dimming material layer 207. In the embodiments shown in FIGS. 4A and 4B , the dimming material layer 207 may be a guest-host LC layer including a mixture of a host LC 408 and a guest dye 410 doped into the LC 408. In the embodiment shown in FIG. 4A , the guest dye 410 may include a dichroic dye (also referred to as 410 for discussion purposes) that is a voltage-responsive dye or an electric field-responsive dye, and the guest-host LC layer may be a voltage-driven guest-host LC layer.

The dichroic dye 410 can be an organic molecule with anisotropic absorption. The absorption properties of the dichroic dye 410 can depend on the relative orientation between the absorption axis of the dichroic dye 410 (e.g., the major axis or minor axis of the dye molecule) and the polarization direction of the incident light. For example, the dichroic dye 410 can relatively strongly absorb the incident light with a polarization direction parallel to the absorption axis of the dye molecule (e.g., the major axis or minor axis), and relatively weakly absorb the incident light with a polarization direction perpendicular to the absorption axis of the dye molecule (e.g., the major axis or minor axis). That is, compared with the incident light with a polarization direction perpendicular to the absorption axis, the dichroic dye 410 can provide a greater dimming effect to the incident light with a polarization direction parallel to the absorption axis of the dye molecule. Therefore, by changing the orientation of the dye molecule through, for example, an electric field, the transmittance of the incident light 142 can be adjusted.

LC 408 in dimming material layer 207 may have positive or negative dielectric anisotropy. For illustrative purposes, FIGS. 4A and 4B show that LC 408 has positive dielectric anisotropy (Δε>0). In the voltage-off state, the dye molecules of dichroic dye 410 may be aligned in the x-axis direction together with LC molecules 408. As shown in FIGS. 4A and 4B, when the director of LC 408 changes from a planar orientation to a vertical orientation with the applied voltage V, the long molecular axis of the dye molecules may also change orientation with LC 408. In other words, the dye molecules may change from a planar orientation (strong absorption state) at V=0 to a vertical orientation (weak absorption state) at V≠0. Therefore, dimming element 400 may switch from operating in a dark state at V=0 to operating in a transparent state at V≠0. In some embodiments, the LC 408 may have a negative dielectric anisotropy (Δε<0), and the opaque state and the transparent state of the dimming element 400 may be reversed, for example, the dimming element 400 may operate in a transparent state at V=0, and operate in a dark state at V≠0. In some embodiments, the dimming element 400 may not include a polarizer. In some embodiments, the dimming element 400 may include a polarizer (not shown), for example, a wire grid polarizer disposed at the upper electrode layer 209-1, and the upper electrode layer 209-1 may be disposed between the polarizer and the upper alignment layer 404.

FIG. 4C shows an x-z cross-sectional view of a dimming element 450 according to an embodiment of the present disclosure. The dimming element 450 may include elements, structures, and/or functions that are the same or similar to those included in the dimming element 400 shown in FIGS. 4A and 4B. The description of the same or similar elements, structures, and/or functions may refer to the above description presented in conjunction with FIGS. 4A and 4B. The dimming element 450 may be an embodiment of the dimming element 166 shown in FIG. 2D or 2E. The dimming element 450 may be a guest-host LC dimming device including a dimming material layer 207, which includes a host LC 408 and a guest dye doped into the LC 408. In some embodiments, the guest dye may include a voltage-responsive dye or an electric field-responsive dye (e.g., a dichroic dye 410) and a photoresponsive dye 460. In some embodiments, the photoresponsive dye 460 may include a photochromic dye, a photodichroic dye, or a combination thereof. 4C , the dimming element 450 may include electrode layers (or conductive layers) 209-1 and 209-2 disposed on opposite sides of the dimming material layer 207 and an alignment layer 404 disposed at opposite surfaces of the dimming material layer 207. The alignment layer 404 is in direct contact with the dimming material layer 207.

In some embodiments, the photoresponsive dye 460 can undergo reversible photoisomerization between at least two stable states (or stable states) with different light absorption effects. During the reversible photoisomerization process, when the photoresponsive dye 460 is subjected to activation energy (e.g., irradiation with activation light), one or more physical properties of the photoresponsive dye 460 (such as absorption spectrum, fluorescence emission, conjugation, electronic conductivity, dipole interaction, and geometry) can change. In some embodiments, the color of the photoresponsive dye 460 can be reversibly changed according to the presence or absence of activation light with a sufficiently high frequency (such as ultraviolet light ("UV"), blue light, and/or violet light). For example, when exposed to UV light (or when the intensity of UV light is greater than a predetermined intensity), the photoresponsive dye 460 can change from a transparent stable state (or referred to as a "transparent state") to a dark stable state (or referred to as a "dark state"), and can be restored to a transparent stable state in the absence of UV light (or when the intensity of UV light is less than a predetermined intensity). The dark stable state may also be referred to as a colored stable state because the photoresponsive dye 460 may appear gray or dark hues in the dark stable state. The transparent stable state may also be referred to as a colorless stable state because the photoresponsive dye 460 may be visually transparent in the transparent stable state.

In some embodiments, the process of returning to the transparent steady state can be accelerated by exposing the photoresponsive dye 460 to other types of activation energy (such as thermal radiation or electromagnetic radiation). For example, in some embodiments, the photoresponsive dye 460 may take longer to return to the transparent steady state in a low temperature environment, and may not achieve a substantially dark steady state in a high temperature environment, because the light-induced (e.g., UV-induced) transition to the dark steady state can be offset by the rapid recovery to the transparent steady state induced by heat. Such a photoresponsive dye 460 may be referred to as a thermally reversible photoresponsive dye, which can return to the transparent steady state at a rate that depends on temperature (e.g., ambient temperature). In some embodiments, the photoresponsive dye 460 can absorb light of different wavelengths to drive the transition to the dark steady state and the transparent steady state, wherein the ambient temperature may have a negligible effect or no effect on the transition speed and the steady state (e.g., dark and clear steady state) properties. Such a photoresponsive dye 460 may be referred to as a thermally stable photoresponsive dye. In some embodiments, one or more infrared ("IR"), visible light, and/or UV light sources can be arranged adjacent to the photoresponsive dye 460 and enabled as needed to illuminate the photoresponsive dye 460. For example, in some embodiments, the thermally stable photoresponsive dye 460 can absorb activation light having a predetermined wavelength to change from a transparent stable state to a dark stable state, and absorb light having a wavelength different from the predetermined wavelength of the activation light to return to the transparent stable state.

5A and 5B show x-z cross-sectional views of a dimming element 500 according to an embodiment of the present disclosure. The dimming element 500 may be an embodiment of the dimming element 166 shown in FIG. 2D or FIG. 2E. The dimming element 500 may be an electro-variable dimming device. As shown in FIG. 5A, the dimming element 500 may include electrode layers 209-1 and 209-2 (collectively referred to as 209) and a dimming material layer 207 disposed between the electrode layer 209-1 and the electrode layer 209-2.

In the embodiment shown in FIG. 5A , the dimming material layer 207 may include at least one electrochromic layer configured to have a light transmittance that changes in response to a change in an applied electric field or current to produce a visual effect. For discussion purposes, as shown in FIG. 5A , the dimming material layer 207 may include an ion storage layer 505, an ion-containing material layer 507 (e.g., an ion-conducting layer or an electrolyte layer), and an electrochromic layer 509 arranged in a stacked configuration. The ion-containing material layer 507 may be disposed between the ion storage layer 505 and the electrochromic layer 509. The electrochromic layer 509 may include an electrochromic material, such as an electrochromic material of an organic small molecule, an electrochromic material including a conductive polymer, or an electrochromic material including a transition metal oxide, etc. The electrochromic material may reversibly change the optical properties of the electrochromic material after electrochemical oxidation and reduction in response to an applied potential (e.g., an applied voltage). For example, the light transmittance of the electrochromic layer 509 may change upon oxidation or reduction of the electrochromic material.

The ion storage layer 505 may be used as a charge storage film that attracts and stores a charged counterpart opposite to the ions that activate or deactivate the electrochromic layer 509. In some embodiments, the ion storage layer 505 may be configured to match the charge balance with the electrochromic layer during a reversible oxidation/reduction reaction for color switching of the electrochromic material included in the electrochromic layer 509. For example, in some embodiments, the ion storage layer 505 may include an electrochromic material having a different color switching reaction characteristic from the electrochromic material included in the electrochromic layer 509. For example, when the electrochromic layer 509 includes a reductive electrochromic material, the ion storage layer 505 may include an oxidative electrochromic material. In some embodiments, the ion-containing material layer 507 may be used as a medium for transmitting ions between the ion storage layer 505 and the electrochromic layer 509. In some embodiments, the ion-containing material layer 507 may effectively block the flow of electrons while allowing ions (typically protons (H ⁺ ) or lithium ions (Li ⁺ )) to pass through.

During operation of the dimming element 500, in some embodiments, as shown in FIG5A, a positive voltage may be applied to the electrode layer 209-1, and a negative voltage (or zero voltage) may be applied to the electrode layer 209-2. The direction of the external electric field generated in the dimming material layer 207 may be along the -z axis direction in FIG5A. The generated electric field may cause charge compensation ions such as lithium ions, sodium ions, or hydrogen ions to enter the electrochromic layer 509 from the ion storage layer 505 via the ion-containing material layer 507. At the same time, electrons may be transmitted along an external circuit and injected into the electrochromic layer 509. The injected electrons may produce an electrochemical reduction of the electrochromic material included in the electrochromic layer 509, thereby producing a colorless (e.g., transparent) state of the dimming device 500.

In some embodiments, as shown in FIG. 5B , a negative voltage (or zero voltage) may be applied to the electrode layer 209-1, and a positive voltage may be applied to the electrode layer 209-2. The direction of the external electric field generated in the dimming material layer 207 may be along the +z axis direction in FIG. 5B . The generated electric field may cause the charge compensation ions to flow out of the electrochromic electrode layer 509 and flow back to the ion storage layer 505 via the ion-containing material layer 507. At the same time, polarity reversal may cause electrons to flow out of the electrochromic electrode layer 509, flow along an external circuit, and flow into the ion storage layer 505. The extraction of electrons may produce electrochemical oxidation of the electrochromic material included in the electrochromic layer 509, thereby producing a colored (e.g., dark) state of the dimming element 500. Referring to FIGS. 5A and 5B , by reversing the polarity of the voltage applied to the dimming element 500, the dimming device element may be able to switch between a colorless state and a colored state.

FIG. 5C shows an x-z cross-sectional view of a dimming element 550 according to an embodiment of the present disclosure. The dimming element 550 may be an embodiment of the dimming element 166 shown in FIG. 2D or FIG. 2E. The dimming element 550 may be an electrochromic dimming element or a suspended particle dimming element. The dimming element 550 may include elements, structures, and/or functions that are the same or similar to the elements, structures, and/or functions included in the dimming element 500 shown in FIG. 5A and FIG. 5B. The description of the same or similar elements, structures, and/or functions may refer to the above description presented in conjunction with FIG. 5A and FIG. 5B.

In the embodiment shown in FIG. 5C , the dimming material layer 207 can be configured to further include a photoresponsive dye 460, such as a photochromic dye, a photodichroic dye, or a combination thereof. The photoresponsive dye 460 can be doped into at least one of the ion storage layer 505, the ion-containing material layer 507, or the electrochromic layer 509. For the purpose of discussion, FIG. 5C shows that the photoresponsive dye 460 is doped into the ion-containing material layer 507. In some embodiments, the photoresponsive dye 460 can be doped into the electrochromic layer 509. In some embodiments, the photoresponsive dye 460 can be doped into the ion storage layer 505.

6A and 6B show x-z cross-sectional views of a dimming element 600 according to an embodiment of the present disclosure. The dimming element 600 may be an embodiment of the dimming element 166 shown in FIG. 2D or FIG. 2E. The dimming element 600 may be an electrophoretic dimming element. As shown in FIG. 6A, the dimming element 600 may include electrode layers 209-1 and 209-2 and a dimming material layer 207 disposed between the two electrode layers 209-1 and 209-2. In the embodiment shown in FIG. 6A, the dimming material layer 207 may include tiny particles 608 suspended in a liquid suspension or a polymer film 610. The particles 608 may be needle-shaped, rod-shaped, or lath-shaped, etc.

In the voltage-off state, as shown in FIG6A , the particles 608 suspended in the liquid suspension or film 610 may be randomly distributed or disordered due to Brownian motion, and the light 142 incident on the dimming material layer 207 may be absorbed and/or scattered. Therefore, the light 142 incident on the dimming material layer 207 may not be transmitted through, and the dimming element 600 may operate in a dark state. In the voltage-on state, as shown in FIG6B , when the applied voltage is high enough, the particles 608 may be uniformly oriented in the direction of the electric field (e.g., the z-axis direction in FIG6B ) to allow the incident light 142 to be substantially transmitted through. Therefore, the dimming element 600 may operate in a transparent state. After the voltage is removed, the particles 608 may move back to the random pattern and substantially block the incident light 142. Therefore, by changing the applied voltage, the light transmittance of the dimming element 600 may be tunable.

FIG6C shows an x-z cross-sectional view of a dimming element 650 according to an embodiment of the present disclosure. The dimming element 650 may be an embodiment of the dimming element 166 shown in FIG2D or FIG2E. The dimming element 650 may be an electrochromic dimming element or a suspended particle dimming element. The dimming element 650 may include elements, structures and/or functions that are the same or similar to the elements, structures and/or functions included in the dimming element 600 shown in FIG6A and FIG6B. The description of the same or similar elements, structures and/or functions may refer to the above description presented in conjunction with FIG6A and FIG6B. In an embodiment as shown in FIG6C, the dimming material layer 207 may be configured to also include a photoresponsive dye 460, such as a photochromic dye, a photodichroic dye, or a combination thereof. The photoresponsive dye 460 may be doped into a liquid suspension or a polymer film 610, which may further enhance the dimming effect of the dimming element 650.

FIG. 7A is a flow chart showing a method 700 for manufacturing a dimming lens according to an embodiment of the present disclosure. The method 700 may include providing a first material layer (step 701). The first material layer may be disposed on a substrate. The method 700 may also include disposing a dimming element at the first material layer (step 702). The dimming element may be disposed at an inner surface (e.g., a concave surface) of the first material layer that faces the user's eyes when the user uses the manufactured dimming lens. The method 700 may also include disposing a second material layer at the dimming element (step 703). The second material layer may be disposed at an inner surface of the dimming element that faces the user's eyes when the user uses the manufactured dimming lens. As described above, the first material layer may include a first lens material having a low density and a low birefringence. As described above, the second material layer may include a second lens material having high impact resistance. The density of the first lens material may be lower than the density of the second lens material. The birefringence of the first lens material may be lower than the birefringence of the second lens material. The impact resistance (or impact strength) of the second lens material may be higher (or stronger) than the impact resistance (or impact strength) of the first lens material. In some embodiments, after providing the first material layer, method 700 may include disposing a dimming element at the second material layer, and disposing a stack of the dimming element and the second material layer at the first material layer. For example, the stack of the dimming element and the second material layer may be disposed at an inner surface (e.g., a concave surface) of the first material layer that faces the user's eyes when the user uses the manufactured dimming lens.

FIG7B is another flow chart showing a method 750 for manufacturing a dimming lens according to an embodiment of the present disclosure. The method 750 may include providing a first material layer, for example, via injection molding (step 751). The method 750 may also include setting a dimming element into a second material layer (step 752). For example, step 752 may include encapsulating the dimming element into the second material layer via a suitable process. The method 750 may also include setting a second material layer including a dimming element at the first material layer, for example, via bonding through an optically transparent adhesive (step 753). The second material layer may be set at the inner surface of the first material layer facing the user's eyes when the user uses the manufactured dimming lens. As described above, the first material layer may include a first lens material having a low density and a low birefringence. As described above, the second material layer may include a second lens material having high impact resistance. The density of the first lens material may be lower than the density of the second lens material. The birefringence of the first lens material may be lower than the birefringence of the second lens material. The impact resistance (or impact strength) of the second lens material may be higher (or stronger) than the impact resistance (or impact strength) of the first lens material.

In some embodiments, the present disclosure provides a lens. The lens includes a first material layer, the first material layer includes a first lens material, the first lens material has a first birefringence, a first density and a first impact resistance. The lens also includes a second material layer, the second material layer is coupled to the first material layer, and the second material layer includes a second lens material, the second lens material has a second birefringence, a second density and a second impact resistance. The first birefringence is lower than the second birefringence, the first density is lower than the second density, and the second impact resistance is stronger than the first impact resistance.

In some embodiments, the lens has an inner side facing the user's eye and an outer side facing the real-world environment, the first material layer is located at the outer side of the lens, and the second material layer is located at the inner side of the lens.

In some embodiments, the first material layer is configured to have a non-zero optical power for providing vision correction, and the second material layer is configured to have zero optical power or an optical power less than a predetermined value.

In some embodiments, the first lens material includes at least one of cycloolefin copolymer or cycloolefin polymer. The second lens material includes at least one of polycarbonate ("PC"), polymethyl methacrylate ("PMMA"), polyethylene ("PE"), polypropylene ("PP"), or polyurethane.

In some embodiments, the first material layer has a concave surface, and the second material layer is laminated to the concave surface of the first material layer. In some embodiments, the lens further comprises a dimming element disposed between the first material layer and the second material layer. In some embodiments, the dimming element comprises a non-electrically tunable dimming material. In some embodiments, the non-electrically tunable dimming material comprises at least one of a photochromic material, a photodichroic material, or a thermochromic material. In some embodiments, the dimming element comprises a first electrode layer disposed at the first material layer and a second electrode layer disposed at the second material layer, and a dimming material disposed between the first electrode layer and the second electrode layer. In some embodiments, each of the first electrode layer and the second electrode layer comprises at least one of indium tin oxide, aluminum-doped zinc oxide, graphene, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), carbon nanotubes, or silver nanowires.

In some embodiments, the dimming material includes an electrically tunable dimming material. The electrically tunable dimming material includes at least one of a guest-host liquid crystal ("LC") material, a polymer-stabilized cholesteric LC material, suspended particles, an electrochromic material, or an electrophoretic material. In some embodiments, the dimming material also includes a non-electrically tunable dimming material. In some embodiments, the second material layer includes a set of two second material layers, and the lens also includes a dimming element disposed between the two second material layers.

In some embodiments, the lens further comprises a dimming material doped into at least one of the first material layer or the second material layer. In some embodiments, the dimming material comprises a non-electrically tunable dimming material.

In some embodiments, the present disclosure provides a system. The system includes a light source configured to output image light. The system also includes an image combiner configured to guide the image light received from the light source to an eyebox area of the system, the image combiner having a first side facing the eyebox area and a second side facing the real world environment. The system also includes a lens disposed at the second side of the image combiner. The lens includes a first material layer, the first material layer including a first lens material, the first lens material having a first birefringence, a first density, and a first impact resistance. The lens also includes a second material layer, the second material layer is coupled to the first material layer, and the second material layer includes a second lens material, the second lens material having a second birefringence, a second density, and a second impact resistance. The first birefringence is lower than the second birefringence, the first density is lower than the second density, and the second impact resistance is stronger than the first impact resistance.

In some embodiments, the present disclosure provides a system. The system includes a light source configured to output image light. The system also includes an image combiner configured to guide the image light received from the light source to an eyebox area of the system, the image combiner including a first side facing the eyebox area and a second side facing the real world environment. The system also includes a lens disposed at the second side of the image combiner. The lens includes a first material layer, the first material layer including a first lens material, the first lens material having a first birefringence, a first density, and a first impact resistance. The lens also includes a second material layer, the second material layer coupled to the first material layer, and the second material layer including a second lens material, the second lens material having a second birefringence, a second density, and a second impact resistance. The first birefringence is lower than the second birefringence, the first density is lower than the second density, and the second impact resistance is stronger than the first impact resistance. The image combiner is at least partially embedded in the second material layer of the lens.

In some embodiments, the present disclosure provides a method. The method includes providing a first material layer, the first material layer including a first lens material, the first lens material having a first birefringence, a first density, and a first impact resistance. The method also includes arranging a dimming element at the first material layer. The method also includes arranging a second material layer at the dimming element. The second material layer includes a second lens material, the second lens material having a second birefringence, a second density, and a second impact resistance. The first birefringence is lower than the second birefringence, the first density is lower than the second density, and the second impact resistance is stronger than the first impact resistance. In some embodiments, arranging the dimming element at the first material layer includes laminating the dimming element to the concave surface of the first material layer via an optical adhesive.

In some embodiments, the stack of the first material layer, the dimming element and the second material layer forms a lens having an inner side facing the user's eyes and an outer side facing the real-world environment, the first material layer is located at the outer side of the lens, and the second material layer is located at the inner side of the lens.

In some embodiments, the first material layer is configured to have a customized optical power for providing vision correction, and the second material layer is configured to have zero optical power or an optical power less than a predetermined value. In some embodiments, the first lens material comprises at least one of a cyclic olefin copolymer or a cyclic olefin polymer. In some embodiments, the first material layer has a retardation value less than 100 nm. In some embodiments, the second lens material comprises at least one of polycarbonate, polymethyl methacrylate, polyethylene, polypropylene, or polyurethane.

In some embodiments, the present disclosure provides a method. The method includes providing a first material layer, the first material layer including a first lens material, the first lens material having a first birefringence, a first density, and a first impact resistance. The method also includes setting a dimming element into a second material layer, the second material layer including a second lens material, the second lens material having a second birefringence, a second density, and a second impact resistance. The method also includes setting the second material layer at the first material layer. The first birefringence is lower than the second birefringence, the first density is lower than the second density, and the second impact resistance is stronger than the first impact resistance. In some embodiments, setting the dimming element into the second material layer includes encapsulating the dimming element into the second material layer. In some embodiments, setting the second material layer at the first material layer includes laminating the second material layer onto a concave surface of the first material layer via an optical bonding layer.

The foregoing description of the embodiments of the present disclosure has been presented for illustrative purposes. This description is not intended to be exhaustive of the present disclosure or to limit the present disclosure to the precise form disclosed. It will be appreciated by those skilled in the relevant art that many modifications and variations are possible based on the above disclosure.

Some parts of this specification may describe embodiments of the present disclosure in terms of algorithms and symbolic representations of operations on information. Although these operations are described functionally, computationally, or logically, these operations may be implemented by computer programs or equivalent circuits, microcodes, etc. In addition, it has been demonstrated that, without loss of generality, arrangements of these operations are sometimes referred to as modules for convenience. The described operations and their associated modules may be embodied in software, firmware, hardware, or any combination thereof.

Any steps, operations or processes described herein may be performed or implemented with one or more hardware and/or software modules, alone or in combination with other devices. In one embodiment, the software modules are implemented with a computer program product, which includes a non-transitory computer-readable medium containing computer program code, which can be executed by a computer processor to perform any or all of the described steps, operations or processes. In some embodiments, the hardware modules may include hardware components, such as devices, systems, optical elements, controllers, electronic circuits, logic gates, etc.

Embodiments of the present disclosure may also relate to a device for performing the operations herein. The device may be specially constructed for a specific purpose, and/or the device may include a general-purpose computing device selectively activated or reconfigured by a computer program stored in a computer. Such a computer program may be stored in a non-transient tangible computer-readable storage medium that can be coupled to a computer system bus, or in any type of medium suitable for storing electronic instructions. A non-transient computer-readable storage medium may be a suitable medium capable of storing program code, for example, a disk, an optical disk, a read-only memory ("ROM") or a random access memory ("RAM"), an electrically programmable read-only memory ("Electrically Programmable Read Only Memory, EPROM"), an electrically erasable programmable read-only memory ("Electrically Erasable Programmable Read Only Memory, EEPROM"), a register, a hard disk, a solid-state disk drive, a smart media card ("Smart Media Card, SMC"), a secure digital card ("Secure Digital, SD"), a flash memory card, etc. In addition, any computing system described in the specification may include a single processor, or may be an architecture that uses multiple processors to improve computing power. The processor may be a central processing unit ("CPU"), a graphics processing unit ("GPU"), or any processing device configured to process data and/or perform calculations based on data. The processor may include software components and hardware components. For example, the processor may include hardware components such as an application-specific integrated circuit ("Application-Specific Integrated Circuit, ASIC"), a programmable logic device ("Programmable Logic Device, PLD"), or any combination thereof. The PLD may be a complex programmable logic device ("Complex Programmable Logic Device, CPLD"), a field programmable gate array ("Field-Programmable Gate Array, FPGA"), etc.

In addition, when the embodiment shown in the drawings shows a single element, it should be understood that the embodiment or the embodiment not shown in the drawings but within the scope of the present disclosure may include multiple such elements. Similarly, when the embodiment shown in the drawings shows multiple such elements, it should be understood that the embodiment or the embodiment not shown in the drawings but within the scope of the present disclosure may include only one such element. The number of elements shown in the drawings is only for illustrative purposes and should not be interpreted as limiting the scope of the embodiment. In addition, unless otherwise specified, the embodiments shown in the drawings are not mutually exclusive, and the embodiments may be combined in any suitable manner. For example, an element shown in one drawing/embodiment but not shown in another drawing/embodiment may still be included in another drawing/embodiment. In any optical device disclosed herein including one or more optical layers, films, plates or elements, the number of layers, films, plates or elements shown in the drawings is only for illustrative purposes. In other embodiments not shown in the drawings but still within the scope of the present disclosure, the same or different layers, films, plates or elements shown in the same or different drawings/embodiments may be combined or repeated in various ways to form a stack.

Various embodiments have been described to illustrate exemplary implementations. Based on the disclosed embodiments, various other changes, modifications, rearrangements and substitutions may be made by those of ordinary skill in the art without departing from the scope of the present disclosure. Therefore, although the present disclosure has been described in detail with reference to the above embodiments, the present disclosure is not limited to the above embodiments. The present disclosure may be embodied in other equivalent forms without departing from the scope of the present disclosure. The scope of the present disclosure is defined in the appended claims.

Claims (15)

1. A lens comprising: a first material layer, the first material layer comprising a first lens material, the first lens material having a first birefringence, a first density, and a first impact resistance; and a second material layer coupled to the first material layer and comprising a second lens material having a second birefringence, a second density, and a second impact resistance, The first birefringence is lower than the second birefringence, the first density is lower than the second density, and the second impact resistance is stronger than the first impact resistance. 2. The lens according to claim 1, wherein: The lens has an inner side facing the user's eye and an outer side facing the real world environment, The first material layer is located at the outer side of the lens, and The second material layer is located at the inner side of the lens. 3. The lens according to claim 1 or claim 2, wherein: The first material layer is configured to have a customized optical power for providing vision correction, and The second material layer is configured to have zero optical power or an optical power less than a predetermined value. 4. A lens according to any preceding claim, wherein the first lens material comprises at least one of a cyclic olefin copolymer or a cyclic olefin polymer, and the second lens material comprises at least one of polycarbonate, polymethyl methacrylate, polyethylene, polypropylene or polyurethane. 5. A lens according to any preceding claim, and one or more of the following: a) wherein the first material layer has a retardation value less than 100 nm; b) the lens further comprises an optically transparent adhesive layer, wherein the optically transparent adhesive layer is disposed between the first material layer and the second material layer; c) wherein the center thickness of the first material layer is in the range of 1.0 mm to 1.5 mm, the center thickness of the second material layer is in the range of 0.2 mm to 0.7 mm, and the optically transparent adhesive layer has a uniform thickness in the range of 0.01 mm to 0.2 mm. 6. A lens according to any preceding claim, and one or more of the following: a) the lens further comprises a dimming element, the dimming element is arranged between the first material layer and the second material layer, and the dimming element comprises at least one of a non-electrically tunable dimming material or an electrically tunable dimming material; b) wherein the second material layer comprises a group of two second material layers, and the lens further comprises a dimming element disposed between the two second material layers; c) The lens further includes a light-adjusting material doped into at least one of the first material layer or the second material layer. 7. A method comprising: Providing a first material layer, the first material layer comprising a first lens material, the first lens material having a first birefringence, a first density, and a first impact resistance; Disposing a dimming element at the first material layer; and A second material layer is disposed at the dimming element, wherein the second material layer includes a second lens material, and the second lens material has a second birefringence, a second density, and a second impact resistance, The first birefringence is lower than the second birefringence, the first density is lower than the second density, and the second impact resistance is stronger than the first impact resistance. 8 . The method of claim 7 , wherein disposing the dimming element at the first material layer comprises laminating the dimming element onto a concave surface of the first material layer via an optically transparent adhesive layer. 9. A method according to claim 7 or claim 8, wherein: The stack of the first material layer, the dimming element and the second material layer forms a lens, The lens has an inner side facing the user's eye and an outer side facing the real world environment, The first material layer is located at the outer side of the lens, and The second material layer is located at the inner side of the lens. 10. The method according to any one of claims 7 to 9, wherein: The first material layer is configured to have a customized optical power for providing vision correction, and The second material layer is configured to have zero optical power or an optical power less than a predetermined value. 11. The method of any one of claims 7 to 10, wherein the first lens material comprises at least one of a cyclic olefin copolymer or a cyclic olefin polymer, and the second lens material comprises at least one of polycarbonate, polymethyl methacrylate, polyethylene, polypropylene, or polyurethane. 12. The method according to any one of claims 7 to 11, wherein the first material layer has a retardation value of less than 100 nm. 13. A method comprising: Providing a first material layer, the first material layer comprising a first lens material, the first lens material having a first birefringence, a first density, and a first impact resistance; placing a dimming element into a second material layer, the second material layer comprising a second lens material, the second lens material having a second birefringence, a second density, and a second impact resistance; and The second material layer is arranged at the first material layer, The first birefringence is lower than the second birefringence, the first density is lower than the second density, and the second impact resistance is stronger than the first impact resistance. 14. The method of claim 13, and one or more of the following: a) wherein arranging the dimming element in the second material layer comprises encapsulating the dimming element in the second material layer; b) wherein arranging the second material layer at the first material layer comprises laminating the second material layer onto the concave surface of the first material layer via an optically clear adhesive layer. 15. A method according to claim 13 or claim 14, wherein: The stack of the first material layer, the dimming element and the second material layer forms a lens, The lens has an inner side facing the user's eye and an outer side facing the real world environment, The first material layer is located at the outer side of the lens, and The second material layer is located at the inner side of the lens.