Light guide display assembly for providing an extended field of view

Abstract

An apparatus includes one or more light guides. The apparatus also includes a first in-coupling element configured to in-couple first light having a first input field of view (“FOV”) into a first light guide, and a second in-coupling element configured to in-couple second light having a second input FOV into a second light guide. The apparatus also includes a first out-coupling element configured to out-couple the first light from the first light guide as first output light having a first output FOV, and a second out-coupling element configured to out-couple the second light from the second light guide as second output light having a second output FOV that is substantially non-overlapping with the first output FOV. A combination of the first output FOV and the second output FOV is greater than at least one of the first output FOV or the second output FOV.

Description

Technical Field

[0001] This disclosure generally relates to devices, and more specifically, to light-guided display components for providing an extended field of view. Background Technology

[0002] Near-eye displays (NEDs) have been widely implemented in a wide variety of applications, such as video playback, gaming, and sports. NEDs have been used to realize virtual reality (VR), augmented reality (AR), or mixed reality (MR). AR or MR headsets display virtual images superimposed on real-world or perspective images. Pupil-expanding lightguide display systems or pupil-expanding lightguide display assemblies with diffraction coupling structures are promising designs for NEDs and can potentially provide sunglasses / eyepiece shape elements, a moderately large field of view (FOV), high transmittance, and a large eye-box. A lightguide display system includes: a display element that generates image light representing a virtual image; and a lightguide coupled to a diffraction coupling structure to guide the image light into the eye-box of the lightguide display system. The diffraction coupling structure, acting as a decoupled diffraction element, replicates the virtual image at the output side of the lightguide to expand the effective pupil. The light guide coupled to the diffraction coupling structure can also act as an optical combiner to combine image light and light from the real world, so that the virtual image represented by the image light generated by the display element overlaps or superimposes with the real-world image represented by the light from the real world. Summary of the Invention

[0003] Consistent with the embodiments disclosed herein, the device according to the invention includes one or more light guides. The device further includes: a first coupling element configured to couple first light having a first input field of view (“FOV”) into the first light guide. The device further includes a second coupling element configured to couple second light having a second input FOV into the second light guide. The device further includes: a first coupling element configured to couple first light from the first light guide as a first output light having a first output FOV. The device further includes a second coupling element configured to couple second light from the second light guide as a second output light having a second output FOV that substantially does not overlap with the first output FOV. A combination of the first output FOV and the second output FOV is greater than at least one of the first output FOV or the second output FOV.

[0004] In one embodiment, the combination of the first output FOV and the second output FOV can be greater than either the first output FOV or the second output FOV.

[0005] In another embodiment, the first coupling element may be configured to couple the first light out from the first light guide at different locations of the first coupling element, and the second coupling element may be configured to couple the second light out from the second light guide at different locations of the second coupling element.

[0006] According to one embodiment, a first coupling element may be configured to substantially couple first light with a first polarization into a first light guide as first total internal reflection (“TIR”) propagation light and substantially transmit second light with a second polarization orthogonal to the first polarization; and a second coupling element may be configured to substantially couple second light with a second polarization into a second light guide as second TIR propagation light and substantially transmit first light with a first polarization. Preferably, a first coupling element may be configured to substantially couple first TIR propagation light with a third polarization out of the first light guide and substantially transmit second TIR propagation light with a fourth polarization orthogonal to the third polarization; and a second coupling element may be configured to substantially couple second TIR propagation light with a fourth polarization out of the second light guide and substantially transmit first TIR propagation light with a third polarization.

[0007] In one embodiment, at least one of the first coupling element, the second coupling element, the first coupling element, or the second coupling element may include a polarization-selective element. Preferably, the polarization-selective element may include a polarization-selective grating or a holographic element, wherein the polarization-selective grating or holographic element includes at least one of a sub-wavelength structure, a liquid crystal, or a photorefractive holographic material. More preferably, the polarization-selective element may include a liquid crystal polymer material having an optical axis with an orientation that spatially varies in both the in-plane and out-of-plane directions.

[0008] According to one embodiment, the device may further include one or more polarization correction films disposed on the surface of at least one of the first light guide or the second light guide, and the one or more polarization correction films are configured to maintain the polarization of at least one of the first light or the second light when the first light and the second light propagate through total internal reflection (“TIR”) inside the first light guide and the second light guide.

[0009] In one embodiment of the device according to the invention, a first coupling element may be configured to couple a first polarization component of a first light from a first light guide during a first subframe of a display frame to serve as a first output light, and a second coupling element may be configured to couple a second polarization component of the first light from a second light guide during the first subframe to serve as a second output light. The device may further include: a polarization switch configured to maintain the polarization of the first output light and the polarization of the second output light during the first subframe; and a polarizer configured to transmit the first output light and block the second output light. Preferably, the first coupling element may be configured to couple a first polarization component of the second light from the first light guide during a second subframe of a display frame to serve as a third output light, the second coupling element may be configured to couple a second polarization component of the second light from the second light guide during the second subframe to serve as a fourth output light, the polarization switch may be configured to change the polarization of the third output light and the polarization of the fourth output light during the second subframe, and the polarizer may be configured to block the third output light and transmit the fourth output light.

[0010] According to another embodiment, the first light guide and the second light guide can be the same single light guide, the first coupling element and the second coupling element can be stacked together or arranged side by side at a single light guide, and the first coupling element and the second coupling element can be stacked together or arranged side by side at a single light guide.

[0011] In one embodiment, the first optical guide and the second optical guide can be different optical guides, the first coupling element and the first coupling element can be connected to the first optical guide, and the second coupling element and the second coupling element can be connected to the second optical guide.

[0012] According to another embodiment, the device of the present invention may further include a light source assembly configured to emit a first light and a second light, wherein the first input FOV is a first portion of a predetermined FOV, and the second input FOV is a second portion of the predetermined FOV. The device may further include a controller configured to control the light source assembly to emit the first light and the second light during the same subframe of a display frame or during two consecutive subframes of a display frame.

[0013] In one embodiment, the device may further include: a light source assembly configured to emit a first light and a second light, wherein each of the first input FOV and the second input FOV corresponds to substantially the same predetermined FOV; and a controller configured to control the light source assembly to emit the first light and the second light respectively during two consecutive subframes.

[0014] In another embodiment, the device may further include: a light source assembly configured to emit a first light and a second light, the light source assembly including a light source and a first polarization switch configured to switch the polarization of at least one of the first light or the second light emitted by the light source; a second polarization switch configured to switch the polarization of at least one of the first output light or the second output light; and a controller configured to synchronize the operating states of the first polarization switch and the second polarization switch.

[0015] According to one embodiment of the device of the present invention, the combination of the first output FOV and the second output FOV may be greater than at least one of the first input FOV or the second input FOV.

[0016] Consistent with the disclosed embodiments, the method according to the present invention includes: coupling a first light having a first input field of view (“FOV”) into a first light guide, and decoupling the first light from the first light guide to serve as a first output light having a first output FOV. The method further includes: coupling a second light having a second input FOV into a second light guide, and decoupling the second light from the second light guide to serve as a second output light having a second output FOV that substantially does not overlap with the first output FOV. The combination of the first output FOV and the second output FOV is greater than at least one of the first output FOV or the second output FOV.

[0017] In one embodiment, the claimed method may further include: generating a first light and a second light during the same subframe of a display frame; or generating a first light during a first subframe and generating a second light during a second subframe, wherein the first subframe and the second subframe are consecutive subframes of the display frame.

[0018] In another embodiment, the first light and the second light may have orthogonal polarizations.

[0019] Other aspects of this disclosure will be understood by those skilled in the art based on the description and accompanying drawings. The foregoing general description and the following detailed description are exemplary and illustrative only, and are not intended to limit the scope of the invention. Attached Figure Description

[0020] The following drawings are provided for illustrative purposes based on various disclosed embodiments and are not intended to limit the scope of this disclosure. In the drawings:

[0021] Figure 1A A schematic diagram of a near-eye display (“NED”) according to an embodiment of the present disclosure is shown;

[0022] Figure 1B Embodiments according to this disclosure are illustrated. Figure 1A The cross-sectional view of half of the NED shown;

[0023] Figure 2A A schematic diagram of a light guide display assembly according to an embodiment of the present disclosure is shown;

[0024] Figure 2B A schematic diagram of a light guide display assembly according to another embodiment of the present disclosure is shown;

[0025] Figure 3 A schematic diagram illustrates a light guide display assembly configured to provide an extended field of view (“FOV”) according to an embodiment of the present disclosure;

[0026] Figure 4 A schematic diagram is shown of a light guide display assembly configured to provide an extended field of view (FOV) according to another embodiment of the present disclosure;

[0027] Figure 5 A schematic diagram illustrates a light guide display assembly configured to provide an extended field of view (FOV) according to an embodiment of the present disclosure;

[0028] Figure 6A and Figure 6B A schematic diagram is shown of a light guide display assembly configured to provide an extended field of view (FOV) according to another embodiment of the present disclosure;

[0029] Figure 7A and Figure 7B A schematic diagram illustrating a light guide display assembly configured to provide an extended field of view (FOV) according to another embodiment of this disclosure is shown; and

[0030] Figure 8 A flowchart illustrating a method for providing an extended field of view (FOV) according to embodiments of the present disclosure is provided. Detailed Implementation

[0031] Embodiments consistent with this disclosure will be described with reference to the accompanying drawings, which are merely illustrative examples and not intended to limit the scope of this disclosure. Where possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts, and detailed descriptions of the same or similar parts may be omitted.

[0032] Furthermore, the disclosed embodiments and features of the disclosed embodiments can be combined in this disclosure. The described embodiments are some, but not all, embodiments of this disclosure. Based on the disclosed embodiments, those skilled in the art can derive other embodiments consistent with this disclosure. For example, modifications, adaptations, substitutions, additions, or other changes can be made based on the disclosed embodiments. These changes to the disclosed embodiments are still within the scope of this disclosure. Therefore, this disclosure is not limited to the disclosed embodiments.

[0033] As used herein, the terms "coupled" (or "coupled") can encompass optical coupling, mechanical coupling, electrical coupling, electromagnetic coupling, or any combination thereof. "Optical coupling" between two optical elements refers to a configuration in which two optical elements are arranged in optical series and the light output from one optical element can be received directly or indirectly by the other. Optical series refers to the optical positioning of multiple optical elements in an optical path such 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 can be direct coupling or indirect coupling (e.g., coupling through an intermediate element).

[0034] The phrase "at least one of A or B" can cover all combinations of A and B, such as A only, B only, or A and B. Similarly, the phrase "at least one of A, B, or C" can cover all combinations of A, B, and C, such as A only, B only, C only, A and B, A and C, B and C, or A and B and C. The phrase "A and / or B" can be interpreted in a similar way to the phrase "at least one of A or B." For example, the phrase "A and / or B" can cover all combinations of A and B, such as A only, B only, or A and B. Likewise, the phrase "A, B, and / or C" has a similar meaning to the phrase "at least one of A, B, or C." For example, the phrase "A, B, and / or C" can cover all combinations of A, B, and C, such as A only, B only, C only, A and B, A and C, B and C, or A and B and C.

[0035] When a first element is described as being "attached," "provided," "formed," "adheded," "mounted," "fixed," "connected," "bonded," "recorded," or "set" onto, on, at, or at least partially in a second element, the first element may be "attached," "provided," "formed," "adheded," "mounted," "fixed," "connected," "bonded," "recorded," or "set" onto, on, at, or at least partially in a second element by any suitable mechanical or non-mechanical means (such as deposition, coating, etching, bonding, gluing, threaded connection, press fit, snap fit, clamping, etc.). Additionally, the first element may be in direct contact with the second element, or there may be an intermediate element between the first and second elements. The first element may be located on any suitable side of the second element (such as left, right, front, back, top, or bottom).

[0036] When a first element is shown or described as being positioned or arranged "on" a second element, the term "on" is used only to indicate an exemplary relative orientation between the first and second elements. This description may be based on a reference coordinate system shown in the figure, or it may be based on the current view or exemplary construction shown in the figure. For example, when describing a view shown in the figure, the first element may be described as being positioned "on" the second element. It should be understood that the term "on" does not necessarily imply that the first element is located above the second element in the vertical, gravitational direction. For example, when the components of the first and second elements are reversed by 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 first element is shown as being "on" the second element, the construction is merely an illustrative example. The first element may be positioned or arranged relative to the second element in any suitable orientation (e.g., above or on top of the second element, below or under the second element, to the left of the second element, to the right of the second element, behind the second element, in front of the second element, etc.).

[0037] When a first element is described as being disposed "on" a second element, the first element may be disposed directly or indirectly on the second element. A first element being directly disposed on the second element indicates that no additional elements are disposed between the first and second elements. A first element being indirectly disposed on the second element indicates that one or more additional elements are disposed between the first and second elements.

[0038] As used herein, the term "processor" 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. A processor may be implemented as software, hardware, firmware, or any combination thereof.

[0039] The term "controller" can cover any suitable circuitry, software, or processor configured to generate control signals for controlling devices, circuits, optical elements, etc. A "controller" can 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.

[0040] The term "non-transitory computer-readable medium" can cover any suitable medium used for storing, transmitting, transporting, broadcasting, or sending data, signals, or information. For example, non-transitory computer-readable media can include memory, hard disks, magnetic disks, optical disks, magnetic tapes, etc. Memory can include read-only memory ("read-only memory (ROM)"), random-access memory ("random-access memory (ROM)"), flash memory, etc.

[0041] The terms "film" and "layer" can include rigid or flexible, self-supporting or self-standing films, coatings, or layers that may be disposed on or between supporting substrates. The phrases "in-plane orientation," "in-plane alignment," "in-plane rotation," "in-plane alignment pattern," and "in-plane spacing" refer to orientation, rotation, alignment pattern, and spacing within a plane of the film or layer (e.g., the surface plane of the film or layer, or a plane parallel to the surface plane of the film or layer), respectively. The term "out-of-plane orientation" indicates a direction that is not parallel to the plane of the film or layer (e.g., perpendicular to the surface plane of the film or layer, for example, perpendicular to a plane parallel to the surface plane). For example, when "in-plane" direction refers to a direction within the surface plane, "out-of-plane" direction can refer to a thickness direction perpendicular to the surface plane, or a direction not parallel to the surface plane.

[0042] The term "orthogonal" as used in "orthogonal polarization" or "orthogonally polarized" as used in "orthogonally polarized" means that the inner product of the two vectors representing the two polarizations is essentially zero. For example, two lights with orthogonal polarization or two orthogonally polarized lights can be two linearly polarized lights with polarization in two orthogonal directions (e.g., the x-axis and y-axis directions in a Cartesian coordinate system), or two circularly polarized lights with opposite rotational properties (e.g., left-handed and right-handed circularly polarized lights).

[0043] In conventional light guide (also known as waveguide) display systems or assemblies, light can propagate within the light guide via total internal reflection (TIR) ​​when the angle of incidence at the inner surface of the light guide (e.g., the angle between light incident on the inner surface and the normal to the inner surface) is greater than or equal to a critical angle. The critical angle can be determined by the refractive index of the material used to manufacture the light guide (provided the external environment of the light guide is air with a refractive index of approximately 1.0). For example, the critical angle for BK-7 glass is approximately 42°. The critical angle can be reduced by applying a reflective coating to the surface of the light guide or by using a material with a higher refractive index to manufacture the light guide. Reducing the critical angle increases the field of view (FOV) provided by the light guide. However, adding a reflective coating or using a material with a higher reflectivity may increase the cost and weight of the light guide. The angle formed by the TIR path of the light / ray and the normal to the inner surface of the light guide (or the angle of incidence of light / ray incident on the inner surface of the light guide) when light propagates within the light guide via TIR can be referred to as the guiding angle or propagation angle. For a light guide made of a conventional glass material (e.g., BK-7 glass), the maximum propagation angle at which light can propagate within the light guide via TIR is approximately 50°.

[0044] Given the limitations of field of view (FOV) in conventional light guide display systems, this invention provides a device (e.g., an optical device) or light guide display assembly comprising a light guide (or light guide stack) and one or more polarization-selective elements coupled to the light guide (or light guide stack). The polarization-selective elements can act as coupling-in and / or coupling-out elements coupled to the light guide (or light guide stack). The coupling-in or coupling-out elements can also be referred to as polarization-selective coupling-in elements or polarization-selective coupling-out elements. The light guide coupled to one or more polarization-selective elements can guide image light representing a virtual image generated by a light source assembly into the eye-friendly region of the optical device in a polarization-multiplexed manner and / or a time-multiplexed manner. The FOV provided by the optical device at the eye-friendly region can be increased (or expanded) compared to the FOV of the image light representing the virtual image coupled to the light guide. For ease of discussion, the FOV of the image light input to the light guide can be referred to as the input FOV, and the FOV of the image light output from the light guide can be referred to as the output FOV. The optical device of this disclosure can provide an increased output FOV (i.e., the output FOV is greater than the input FOV). In some embodiments, any one of the plurality of polarization-selective elements may include one or more polarization-selective gratings or holographic elements made of isotropic or anisotropic materials. The polarization-selective gratings or holographic elements may include suitable subwavelength structures, liquid crystals, photorefractive holographic materials, or any combination thereof. In some embodiments, at least one of the polarization-selective coupling elements or polarization-selective coupling elements may be a linear polarization-selective element. In some embodiments, at least one of the polarization-selective coupling elements or polarization-selective coupling elements may be a circular polarization-selective element.

[0045] In some embodiments, the optical device may include a light guide. The optical device may include a first polarization-selective coupling element (e.g., a first polarization-selective coupling grating) configured to couple a first input light having a first polarization and a first input FOV (e.g., via diffraction) into a TIR path within the light guide. The optical device may also include a second polarization-selective coupling element (e.g., a second polarization-selective coupling grating) configured to couple a second input light having a second polarization orthogonal to the first polarization and having a second input FOV into the TIR path within the light guide. The first and second input lights can propagate within the light guide via TIR as first TIR propagation light and second TIR propagation light, respectively. The optical device may also include a first polarization-selective coupling element (e.g., a first polarization-selective coupling grating) configured to couple the first TIR propagation light out of the light guide as a first output light having a first output FOV. The optical device may include a second polarization-selective coupling element (e.g., a second polarization-selective coupling grating) configured to couple a second TIR propagating light from a photoguide as a second output light having a second output FOV. The first and second output lights may have orthogonal polarizations. The first and second output FOVs may be substantially non-overlapping. In some embodiments, the first and second output FOVs may be substantially non-overlapping consecutive FOVs (e.g., 0° to +50°, 0° to -50°). The combination of the first and second output FOVs may be substantially greater than each of the first and second output FOVs. In some embodiments, the combination of the first and second output FOVs may be greater than the combination of the first and second input FOVs.

[0046] In some embodiments, the optical device may include a light guide stack comprising a plurality of light guides. For example, the light guide stack may include a first light guide and a second light guide. A first polarization-selective coupling element (e.g., a first polarization-selective coupling grating) and a first polarization-selective coupling element (e.g., a first polarization-selective coupling grating) may be connected to the first light guide. A second polarization-selective coupling element (e.g., a second polarization-selective coupling grating) and a second polarization-selective coupling element (e.g., a second polarization-selective coupling grating) may be connected to the second light guide. The first polarization-selective coupling element (e.g., the first polarization-selective coupling grating) may be configured to couple a first input light having a first input FOV (e.g., via diffraction) into a first TIR path within the first light guide as a first TIR propagation light. The first TIR propagation light may propagate along the first TIR path within the first light guide toward the first polarization-selective coupling element.

[0047] A first polarization-selective coupling element (e.g., a first polarization-selective coupling grating) can be configured to couple a first TIR propagating light from a first light guide (e.g., via diffraction) as a first output light corresponding to a first output FOV. A second polarization-selective coupling element (e.g., a second polarization-selective coupling grating) can be configured to couple a second input light having a second input FOV (e.g., via diffraction) into a second TIR path within a second light guide as a second TIR propagating light. The second TIR propagating light can propagate via TIR along the second TIR path within the second light guide. A second polarization-selective coupling element (e.g., a second polarization-selective coupling grating) can be configured to couple the second TIR propagating light from a second light guide (e.g., via diffraction) as a second output light corresponding to a second output FOV. The first output light and the second output light can have orthogonal polarizations. The first output FOV and the second output FOV can be substantially non-overlapping. In some embodiments, the first output FOV and the second output FOV can be substantially non-overlapping consecutive FOVs (e.g., 0° to +50°, 0° to -50°). The combination of the first output FOV and the second output FOV can be substantially greater than each of the first input FOV and the second input FOV. In some embodiments, the combination of the first output FOV and the second output FOV can be greater than the combination of the first input FOV and the second input FOV.

[0048] In some embodiments, the first input light and the second input light may correspond to different portions of the same field of view (FOV) of light (or image light) emitted from a light source coupled to a light guide or light guide stack. Image light emitted from the light source may represent a virtual image. For example, the FOV of the image light may include two portions: a first portion and a second portion (e.g., a left half and a right half). The first and second portions of the FOV may correspond to the first and second input FOVs of the first and second input light. The light guide or light guide stack may be configured to receive the first and second input light corresponding to different portions of the FOV during the same time period (e.g., simultaneously within the same time period), or to receive the first and second input light corresponding to different portions of the FOV in a temporal sequence (e.g., in two consecutive time instances, one light is received before the other).

[0049] In some embodiments, each of the first and second input lights may correspond to the full FOV of image light (representing a virtual image) emitted from a light source coupled to a light guide or light guide stack. That is, the first input FOV of the first input light may correspond to the full FOV of the image light emitted by the light source, and the second input FOV of the second input light may correspond to the full FOV of the image light emitted by the light source. The light guide or light guide stack may be configured to receive the first and second input lights, each corresponding to a full FOV of the image light, in a time-sequential manner (e.g., in two consecutive time instances, one input light may be received before the other). In some embodiments, the combination of the first and second output FOVs at the output side of the light guide display component may be greater than the FOV of the image light generated by the light source. In some embodiments, the first TIR propagation light within the light guide may correspond to a first intermediate FOV, which is smaller than the first input FOV of the first input light. The second TIR propagation light within the light guide may correspond to a second intermediate FOV, which is smaller than the second input FOV of the second input light. The combination of the first output FOV and the second output FOV at the output side of the light guide display component can be greater than the combination of the first intermediate FOV of the first TIR propagating light and the second intermediate FOV of the second TIR propagating light within the light guide. In some embodiments, the combination of the first output FOV and the second output FOV at the output side of the light guide display component can be greater than each of the first input FOV and the second input FOV (each corresponding to the full FOV of the image light emitted by the light source).

[0050] In some embodiments, at least one first TIR propagation ray included in the first TIR propagation light and at least one second TIR propagation ray included in the second TIR propagation light may have substantially the same propagation angle when propagating within the light guide via TIR. In some embodiments, a first polarization-selective coupling element may be configured to couple at least one first TIR propagation ray from the light guide (or a first light guide included in a light guide stack) as at least one first output ray propagating in at least one first direction (or a first output angle). In some embodiments, a second polarization-selective coupling element may be configured to couple at least one second TIR propagation ray from the light guide (or a second light guide included in a light guide stack) as at least one second output ray propagating in at least one second direction (or a second output angle). The output angle may be defined as the angle between the output ray and the normal to the surface of the coupling element. The output angle may be defined as positive or negative depending on the clockwise or counterclockwise relationship between the output ray and the normal to the surface of the coupling element. The first direction (or first output angle) and the second direction (or second output angle) may be different directions (or different output angles). In some embodiments, the first output angle and the second output angle may be opposite output angles. For example, the first output angle and the second output angle can have the same absolute value and opposite signs (e.g., θ and -θ). In some embodiments, the first output angle and the second output angle can have different absolute values ​​and opposite signs (e.g., θ1 and -θ2, where θ1 and θ2 have different values).

[0051] In conventional light guide display assemblies, the propagation angle of the TIR path within the light guide corresponds one-to-one with the output angle of the output light rays coupled from the light guide. In this disclosure, the propagation angle of the TIR path within the light guide can be mapped to two different output angles, for example, two output angles with opposite signs. Therefore, when the light guides (or light guide stacks) included in the disclosed light guide display assembly and conventional light guide display assemblies are manufactured using similar or identical materials with similar or identical refractive indices, the FOV provided by the disclosed light guide display assembly can be enlarged, increased, or expanded (e.g., doubled) compared to the FOV provided by the conventional light guide display assembly. The disclosed light guide display assembly can utilize light guides manufactured from materials with lower refractive indices to provide the same or similar FOV compared to conventional light guide display assemblies.

[0052] In some embodiments, when a single light guide is used to transmit two different portions of the FOV of the image light generated by the light source component, a multicolor (e.g., panchromatic) 2D pupil expansion (or replication) can be achieved by stacking three light guides. These three light guides are configured to transmit component color images (e.g., primary color images) by coupling in, and subsequently out, for example, red, green, and blue light in any suitable order. In some embodiments, when a single light guide is used to transmit different portions of the FOV of the image light, a multicolor (e.g., panchromatic) 2D pupil expansion (or replication) can be achieved by stacking two light guides. These two light guides are configured to transmit component color images (e.g., primary color images) by coupling in, and subsequently out, for example, a combination of red and green light, and a combination of green and blue light, in any suitable order.

[0053] In some embodiments, when a single light guide stack having multiple light guides stacked together is used to transmit two different portions of the FOV of image light, multicolor (e.g., panchromatic) 2D pupil expansion (or replication) can be achieved by stacking three light guide stacks, which are configured to transmit component color images (e.g., primary color images) by coupling in, and subsequently out, for example, red, green, and blue light in any suitable order. In some embodiments, when a single light guide stack is used to transmit different portions of the FOV of image light, multicolor (e.g., panchromatic) 2D pupil expansion (or replication) can be achieved by stacking two light guide stacks, which are configured to transmit component color images (e.g., primary color images) by coupling in, and subsequently out, for example, a combination of red and green light, and a combination of green and blue light, in any suitable order.

[0054] Figure 1A A schematic diagram of a near-eye display (“NED”) 100 according to an embodiment of the present disclosure is shown. In some embodiments, the NED 100 may be referred to as a “head-mounted display” (“HMD”). The NED 100 may present media content to a user, such as one or more images, one or more videos, one or more audio files, or combinations thereof. In some embodiments, audio content may be presented to the user via an external device (e.g., speakers and / or headphones). The NED 100 may operate as a VR device, an AR device, a MR device, or a combination thereof. In some embodiments, when the NED 100 operates as an AR device and / or a MR device, a portion of the NED 100 may be at least partially transparent, and the internal components of the NED 100 may be at least partially visible.

[0055] like Figure 1AAs shown, NED 100 may include a frame 110, a left display system 120L, and a right display system 120R. In some embodiments, these components may be omitted. Figure 1A One or more devices are shown in the diagram. In some embodiments, the NED 100 may also include... Figure 1A One or more additional devices or components not shown. Frame 110 may include a suitable type of mounting structure configured to mount the left display system 120L and right display system 120R to a user's body part (e.g., head) (e.g., adjacent to the user's eyes). Frame 110 may be coupled to one or more optical elements that can be configured to display media content to the user. In some embodiments, frame 110 may represent the frame of glasses. The left display system 120L and right display system 120R may be configured to allow the user to view virtual content presented by NED 100 and / or view images of real-world objects. For example, in some embodiments, each of the left display system 120L and right display system 120R may include a perspective optics element. In some embodiments, the left display system 120L and right display system 120R may include any suitable display component (not shown) configured to generate light (e.g., image light corresponding to a virtual image) and direct the image light to the user's eyes. In some embodiments, NED 100 may include a projection system. For illustrative purposes, Figure 1A The projection system is shown to include a projector 135 attached to the frame 110.

[0056] Figure 1B According to embodiments of this disclosure Figure 1A The cross-sectional view of NED 100 is shown. For illustrative purposes, Figure 1B A cross-sectional view associated with the left display system 120L of the NED 100 is shown. The cross-sectional view of the right display system 120R can be similar to the cross-sectional view shown for the left display system 120L. Figure 1B As shown, for eye 160, the left display system 120L may include an optical device 115 for delivering image light with an extended field of view (“FOV”) to eye 160. In some embodiments, the optical device 115 may be a light-guide display assembly 115. The light-guide display assembly 115 may include a light guide or a light guide stack. The exit pupil 125 may be located at a position where eye 160 is within the eye-fitting zone 165 when the user is wearing NED 100. For illustrative purposes, Figure 1B A cross-sectional view is shown in association with a single eye 160 and a single light guide display assembly 115. In some embodiments, with Figure 1B The light guide display component 115 shown is separate from another similar light guide display component, which can provide image light to the eye-friendly area located at the exit pupil of the user's other eye.

[0057] The light guide display assembly 115 may include a light guide and / or one or more gratings, the light guide and gratings being manufactured based on one or more materials (e.g., plastic, glass, etc.) having one or more refractive indices. The light guide display assembly 115 can effectively minimize the weight of the NED 100 and increase (or extend) the field of view (“FOV”) of the NED 100. In some embodiments, the light guide display assembly 115 may be a component of the NED 100. In some embodiments, the light guide display assembly 115 may be a component of another NED, or a component of another system that guides image light to a specific location. Figure 1B As shown, a light guide display component 115 can be provided for one of the user's eyes 160. The light guide display component 115 for one eye can be separate or partially separate from a similar light guide display component for the other eye. In some embodiments, a single light guide display component 115 can be used for both of the user's eyes.

[0058] In some embodiments, NED 100 may include one or more optical elements (not shown) disposed between the light guide display assembly 115 and the eye 160. The optical elements may be configured to, for example, correct aberrations in the image light emitted from the light guide display assembly 115, amplify the image light emitted from the light guide display assembly 115, or perform another type of optical adjustment of the image light emitted from the light guide display assembly 115. Examples of one or more optical elements may include apertures, Fresnel lenses, convex lenses, concave lenses, filters, any other suitable optical elements affecting image light, or combinations thereof. In some embodiments, the light guide display assembly 115 may include a stack of light guide displays. In some embodiments, a stacked light guide display may include a multicolor display (e.g., a red-green-blue (“RGB”) display) formed by stacking light guide displays. The respective monochromatic light sources included in the light guide displays may be configured to emit light of different colors. For example, a stacked light guide display may include a multicolor display (e.g., a multifocal color display) configured to project image light onto multiple planes. In some embodiments, the stacked light guide display may include a monochrome display (e.g., a multifocal monochrome display) configured to project image light onto multiple planes. Various embodiments of the light guide display assembly 115 will be described below.

[0059] In some embodiments, the NED 100 may include an adaptive dimming element 130 that dynamically adjusts the transmittance of real-world light from the real-world environment to switch the NED 100 between VR and AR devices or between VR and MR devices. In some embodiments, the adaptive dimming element 130 may be used in AR and / or MR devices to mitigate brightness differences between real and virtual objects as the device switches between AR / MR and VR devices.

[0060] Figure 2A A schematic diagram of an optical system or optical device 200 according to an embodiment of the present disclosure is shown. The optical device 200 may also be referred to as a light guide display assembly (or light guide display system) 200. The light guide display assembly 200 can be used in NEDs (such as those for VR applications, AR applications, and / or MR applications) for VR applications, AR applications, and / or MR applications. Figure 1A and Figure 1B This is implemented in the NED 100 shown. For example, the light guide display component 200 can be... Figure 1A and Figure 1B An embodiment of the light guide display component 115 shown (or may be similar to the light guide display component 115).

[0061] like Figure 2A As shown, the light guide display assembly 200 may include a light source assembly 205, a light guide 210, and a controller 215. The controller 215 may include a processor or processing unit 201. The processor may be any suitable processor, such as a central processing unit (“CPU”), a graphics processing unit (“GPU”), etc. The controller 215 may include a storage device 202. The storage device 202 may be a non-transitory computer-readable medium, such as a memory, a hard disk, etc. The storage device 202 may be configured to store data or information including computer-executable program instructions or code that can be executed by the processor 201 to perform various controls or functions of the methods or processes disclosed herein.

[0062] The light source assembly 205 may include a light source 220 and a light conditioning system 225. The light source 220 may be any suitable light source configured to generate light (e.g., image light representing a virtual image and having a predetermined field of view). In some embodiments, the light source 220 may be a light source configured to generate coherent or partially coherent light. The light source 220 may include, for example, a laser diode, a vertical-cavity surface-emitting laser, a light-emitting diode, or a combination thereof. In some embodiments, the light source 220 may include a display panel, such as a liquid crystal display (“LCD”) panel, a liquid-crystal-on-silicon (“LCoS”) display panel, an organic light-emitting diode (“OLED”) display panel, a micro light-emitting diode (“micro LED”) display panel, a digital light processing (“DLP”) display panel, or a combination thereof. In some embodiments, the light source 220 may include a self-emissive panel, such as an OLED display panel or a micro LED display panel. In some embodiments, light source 220 may include a display panel illuminated by an external source, such as an LCD panel, an LCoS display panel, or a DLP display panel. Examples of external sources may include lasers, LEDs, OLEDs, or combinations thereof.

[0063] The light conditioning system 225 may include one or more optical components configured to condition the light emitted by the light source 220. In some embodiments, the light conditioning system 225 may be controlled by the controller 215 to perform various conditioning of the light emitted by the light source 220. Conditioning the light may include, for example, emitting light, attenuating light, spreading light, collimating light, and / or adjusting the orientation of light.

[0064] The light source assembly 205 can generate image light 230 and output image light 230 toward a coupling element 235 coupled to the light guide 210. For example, the coupling element 235 can be located at a first portion of the light guide 210. The coupling element 235 can couple the image light 230 into a total internal reflection (“TIR”) path within the light guide 210. The light guide 210 can guide the image light 230 from the coupling element 235 to a coupling element 245 coupled to the light guide 210. For example, the coupling element 245 can be located at a second portion of the light guide 210. The image light 230 coupled by the coupling element 235 can propagate within the light guide 210 via TIR as TIR propagation light 231 toward the coupling element 245. The first and second portions can be located at different positions within the light guide 210. The coupling element 245 can be configured to couple the TIR propagation light 231 out of the light guide 210 as output light 232 toward the eye 260. When the TIR propagating light 231 is incident on different positions of the coupling element 245, the coupling element 245 can continuously couple the TIR propagating light 231 out of the light guide 210 at different positions. Therefore, the coupling element 245 can replicate the image light to expand the effective pupil of the light guide display assembly 200. In some embodiments, the light guide 210 can receive light 255 from the real-world environment and can combine the light 255 with the output light 232 (which can be the image light) and deliver the combined light to the eye 260.

[0065] The light guide 210 may include a first surface or first side 210-1 facing the real-world environment, and a opposite second surface or second side 210-2 facing the eye 260. Depending on the location of the light source assembly 205 and the type of coupling element 235, the coupling element 235 may be disposed on the first surface 210-1 or the second surface 210-2, and may be disposed on the same side of the light guide 210 as the light source assembly 205. In some embodiments, the coupling element 235 and the light source assembly 205 may be disposed on different sides of the light guide 210. Figure 2A In the illustrated embodiment, the coupling element 235 is disposed at the first surface 210-1 of the light guide 210. In some embodiments, the coupling element 235 may be integrally formed as part of the light guide 210 at the first surface 210-1.

[0066] In some embodiments, the coupling element 235 may be formed or disposed at a first surface 210-1 of the light guide 210 (e.g., adhered to the first surface 210-1 of the light guide 210) as a separate element. In some embodiments, the coupling element 235 may be disposed at a second surface 210-2 of the light guide 210 as a separate element. In some embodiments, the coupling element 235 may be integrally formed as part of the light guide 210 at the second surface 210-2. In some embodiments, the coupling element 235 may include one or more diffraction gratings, one or more cascaded reflectors, one or more prismatic surface elements, and / or an array of holographic reflectors, or any combination thereof. In some embodiments, the coupling element 235 may include one or more polarization-selective elements, and the coupling element may be referred to as a polarization-selective coupling element. The polarization-selective element may include a polarization-selective grating or holographic element made of isotropic or anisotropic materials. The polarization-selective grating or holographic element may include a suitable subwavelength structure, liquid crystal, photorefractive holographic material, or any combination thereof. The spacing of the polarization-selective gratings included in the coupling element 235 can be configured to achieve total internal reflection (“TIR”) of the image light 230 within the light guide 210. Therefore, the image light 230 coupled to the light guide 210 by the coupling element 235 can propagate within the light guide 210 via TIR along the TIR path 213 at a propagation angle α. Figure 2A As shown, the propagation angle α can be defined as the angle formed between the TIR path 213 and the normal 223 of the inner surface of the light guide 210.

[0067] The coupling element 245 can be disposed on the first surface 210-1 or the second surface 210-2 of the light guide 210. For example, Figure 2A As shown, the coupling element 245 may be disposed at the second surface 210-2 of the light guide 210. In some embodiments, the coupling element 245 may be integrally formed as part of the light guide 210. In some embodiments, the coupling element 245 may be formed or disposed at the second surface 210-2 of the light guide 210 (e.g., adhered to the second surface 210-2 of the light guide 210) as a separate element. In some embodiments, the coupling element 245 may be disposed at the first surface 210-1 of the light guide 210. For example, in some embodiments, the coupling element 245 may be integrally formed as part of the light guide 210 at the first surface 210-1. In some embodiments, the coupling element 245 may be formed or disposed at the first surface 210-1 of the light guide 210 (e.g., adhered to the first surface 210-1 of the light guide 210) as a separate element.

[0068] In some embodiments, the coupling element 245 may include one or more diffraction gratings, one or more cascaded reflectors, one or more prismatic surface elements, and / or an array of holographic reflectors, or any combination thereof. In some embodiments, the coupling element 245 may include one or more polarization-selective elements, and the coupling element 245 may be referred to as a polarization-selective coupling element. The polarization-selective element may include a polarization-selective grating or holographic element made of isotropic or anisotropic materials. The polarization-selective grating or holographic element may include a suitable subwavelength structure, liquid crystal, photorefractive holographic material, or any combination thereof. The spacing of the polarization-selective gratings included in the coupling element 245 may be configured such that the polarization-selective gratings diffract the image light 230 from the light guide 210. As a result, TIR no longer occurs.

[0069] The light guide 210 may include one or more materials configured to induce total internal reflection of the image light 230. The light guide 210 may include, for example, plastic, glass, and / or polymer. The light guide 210 may have relatively small shape features. For example, the light guide 210 may be approximately 50 mm wide along the x-axis, 30 mm long along the y-axis, and 0.5 mm to 1 mm thick along the z-axis.

[0070] The controller 215 can be communicatively coupled to the light source assembly 205, and the controller 215 can control the operation of the light source assembly 205. In some embodiments, the light guide display assembly 200 can be configured to guide input image light 230 toward the eye 260 as output image light 232 to increase or expand the field of view (“FOV”). For example, the output FOV of the image light 232 provided to the eye 260 can be equal to or greater than 60 degrees and equal to or less than 150 degrees in the x-axis direction and / or y-axis direction. The light guide 210 can be configured to provide an eye-friendly area with a width equal to or greater than 8 mm and equal to or less than 50 mm, and a height equal to or greater than 6 mm and equal to or less than 20 mm. Using the light guide display assembly 200, the physical display and electronics can be moved to one side of the front body of the NED, and a substantially unobstructed field of view of the real-world environment can be achieved, which enhances the AR user experience.

[0071] In some embodiments, the light guide 210 may include one or more additional elements configured to redirect, fold, and / or extend the image light 230 toward the coupling element 245. Figure 2B A schematic diagram of an optical system or optical device 250 according to an embodiment of the present disclosure is shown. The optical system 250 may be configured to provide an extended field of view (FOV) (e.g., an extended FOV of image light transmitted by the optical system 250). The optical system 250 may also be referred to as a light guide display assembly 250. The light guide display assembly 250 may include components related to… Figure 2AThe light guide display assembly 200 shown includes similar or identical elements. A description of the same or similar elements can be found above. Figure 2A The presented description.

[0072] For example, such as Figure 2B As shown, the light guide display assembly 250 may include a light guide 210, a light source assembly 205, a coupling element 235, a coupling element 245, and a controller 215. The light guide display assembly 250 may also include a guiding element 240 configured to redirect image light 230 to the coupling element 245, such that the image light 230 can be coupled out of the light guide 210 through the coupling element 245. In some embodiments, the guiding element 240 may be disposed at a surface position opposite to the position of the coupling element 245. In some embodiments, the guiding element 240 may be disposed on a first surface 210-1 of the light guide 210, and located at a position corresponding to and opposite to the position of the coupling element 245 on a second surface 210-2. In some embodiments, the guiding element 240 may be integrally formed as part of the light guide 210 on the first surface 210-1. In some embodiments, the guiding element 240 may be formed or disposed on the first surface 210-1 of the light guide 210 (e.g., adhered to the first surface 210-1 of the light guide 210) as a separate element. In some embodiments, the guiding element 240 may be disposed at the second surface 210-2 of the light guide 210, and the coupling element 245 may be disposed opposite the guiding element 240 at the first surface 210-1. For example, in some embodiments, the guiding element 240 may be integrally formed as part of the light guide 210 at the second surface 210-2. In some embodiments, the guiding element 240 may be formed or disposed at the second surface 210-2 of the light guide 210 (e.g., adhered to the second surface 210-2 of the light guide 210) as a separate element. In some embodiments, the guiding element 240 and the coupling element 245 may be disposed at the same surface of the light guide 210. For example, the guiding element 240 and the coupling element 245 may be stacked together.

[0073] In some embodiments, the guiding element 240 and the coupling element 245 may have similar structures. In some embodiments, the guiding element 240 may include one or more diffraction gratings, one or more cascaded reflectors, one or more prismatic surface elements, and / or an array of holographic reflectors, or any combination thereof. In some embodiments, the guiding element 240 may include one or more polarization-selective elements, and the guiding element may be referred to as a polarization-selective guiding element. The polarization-selective element may include a polarization-selective grating or holographic element made of isotropic or anisotropic materials. The polarization-selective grating or holographic element may include a suitable subwavelength structure, liquid crystal, photorefractive holographic material, or any combination thereof. The guiding element 240 may also be referred to as folding element 240. In some embodiments, multiple functions (e.g., redirecting, folding, and / or extending the image light 230 generated by the light source assembly 205) may be combined into a single element (e.g., coupling element 245). In such embodiments, the guiding element 240 may be omitted.

[0074] Figures 3 to 7B A schematic diagram illustrating a light-guided display assembly configured to provide an extended field of view (FOV) according to various embodiments of the present disclosure is shown. For illustrative and discussion purposes, each of the polarization-selective coupling elements, polarization-selective coupling elements, and / or polarization-selective guiding elements shown in the figures may include one or more polarization-selective gratings, such as transmissive or reflective polarization-selective gratings. The polarization-selective grating included in the polarization-selective coupling element may be referred to as a polarization-selective coupling grating. The polarization-selective grating included in the polarization-selective coupling element may be referred to as a polarization-selective coupling grating. For illustrative and discussion purposes, all polarization-selective coupling gratings and all polarization-selective coupling gratings shown in the figures may be of the same type (e.g., transmissive or reflective). In some embodiments, the polarization-selective coupling gratings may be of different types. In some embodiments, the polarization-selective coupling gratings and the polarization-selective coupling gratings may be of different types.

[0075] In some embodiments, the polarization-selective element may comprise an optically anisotropic material (e.g., LC material). The optical axis of the optically anisotropic material may be configured to have a spatially varying orientation in both in-plane and out-of-plane directions to provide a polarization-sensitive holographic response. In some embodiments, the optically anisotropic material including an optical axis (with such a spatially varying orientation) may form a polarization volume hologram ("PVH") or a PVH element. The term "optical axis" may refer to a direction in the crystal. Light propagating in the direction of the optical axis may not undergo birefringence. The optical axis may be a direction rather than a single line: light parallel to this direction may not undergo birefringence. In some embodiments, the PVH may be configured to primarily (or substantially) diffract circularly polarized light (or elliptically polarized light) with a predetermined handedness, and primarily (or substantially) transmit (e.g., with negligible diffraction) circularly polarized light (or elliptically polarized light) with a handedness opposite to the predetermined handedness. It should be understood that a PVH can transmit circularly polarized light (or elliptically polarized light) with a predetermined directionality, and its transmittance is much lower than that of circularly polarized light (or elliptically polarized light) with a directionality opposite to the predetermined directionality. A PVH can diffract circularly polarized light (or elliptically polarized light) with a directionality opposite to the predetermined directionality, and its diffraction efficiency is much lower than that of circularly polarized light (or elliptically polarized light) with the predetermined directionality.

[0076] Unpolarized or linearly polarized light can be decomposed into two circularly polarized components with opposite directions of rotation (e.g., a first component and a second component). Therefore, the first component can be primarily diffracted by a PVH, and the second component can be primarily transmitted by the PVH (e.g., with negligible diffraction). A PVH can be configured to primarily (or substantially) diffract circularly polarized light (or elliptically polarized light) with a predetermined direction of rotation forward or backward. When a PVH is configured to primarily (or substantially) diffract circularly polarized light (or elliptically polarized light) with a predetermined direction of rotation forward, it can be called a transmissive PVH. When a PVH is configured to primarily (or substantially) diffract circularly polarized light (or elliptically polarized light) with a predetermined direction of rotation backward, it can be called a reflective PVH.

[0077] In some embodiments, a PVH may include optically anisotropic molecules (e.g., LC molecules) arranged in multiple helical structures within the volume of the PVH. The orthotropic nature of the helical structures can define the polarization selectivity of the PVH. In some embodiments, the PVH may be configured to primarily (or substantially) diffract circularly polarized (or elliptically polarized) light having the same orthotropic nature as the helical structures, and primarily (or substantially) transmit (e.g., with negligible diffraction) circularly polarized (or elliptically polarized) light having an orthotropic nature opposite to that of the helical structures. In some embodiments, the optically anisotropic molecules in the PVH may not be arranged in multiple helical structures within the volume of the PVH. The orthotropic nature of the rotation of the directores of the optically anisotropic molecules at the optically anisotropic molecular director plane can define the polarization selectivity of the PVH. The optically anisotropic molecular director plane (or molecular director plane) is a plane formed by the directores of the optically anisotropic molecules, or a plane including the directores of the optically anisotropic molecules. Optically anisotropic molecules can be arranged in multiple parallel molecular director planes within the volume of the PVH. In some embodiments, the PVH can be configured to primarily (or substantially) diffract circularly polarized light (or elliptically polarized light) having the same directionality as the rotation of the optically anisotropic molecules' director at the molecular director plane, and primarily (or substantially transmit, e.g., with negligible diffraction) circularly polarized light (or elliptically polarized light) having the opposite directionality to the rotation of the optically anisotropic molecules' director at the molecular director plane.

[0078] In some embodiments, a PVH may be referred to as a left-handed PVH or a right-handed PVH, depending on the helical orientation of the helical structure within the volume of the PVH, or the helical orientation of the molecular director in the molecular director plane within the volume of the PVH. For example, a left-handed PVH may be configured to primarily (forward or backward) diffract left-handed circularly polarized (“LHCP”) light and primarily transmit (e.g., with negligible diffraction) right-handed circularly polarized (“RHCP”) light. A right-handed PVH may be configured to primarily (forward or backward) diffract RHCP light and primarily transmit (e.g., with negligible diffraction) LHCP light.

[0079] In the following description, for illustrative purposes, a polarization-selective grating including a PVH (also referred to as a PVH grating) can be used as an example of a polarization-selective coupling element, a polarization-selective coupling element, and / or a polarization-selective guiding element / folding element. In some embodiments, the light guide display assembly may also include other suitable polarization-selective elements to provide an extended FOV, following the same or similar design principles described herein with respect to embodiments having one or more light guides coupled to one or more PVH gratings. Additionally, for illustrative purposes, a one-dimensional (“1D”) FOV extension (e.g., a horizontal FOV extension) is used as an example to explain the principles of an extended FOV. In some embodiments, a two-dimensional (“2D”) FOV extension (e.g., a horizontal FOV extension and a vertical FOV extension) can also be achieved by introducing one or more additional polarization-selective elements (e.g., polarization-selective folding elements or guiding elements) configured to redirect light toward a polarization-selective coupling element at a 90° angle. Although a polarization-selective grating can be used as an example of a polarization-selective element included in a polarization-selective coupling element, coupling element, and / or guiding element, the polarization-selective element included in such a coupling element, coupling element, and / or guiding element is not limited to a polarization-selective grating.

[0080] Figure 3 A schematic diagram of an optical system or optical device 300 according to an embodiment of the present disclosure is shown. The optical device 300 may also be referred to as a light guide display assembly 300. The light guide display assembly 300 can be configured to provide an extended field of view (FOV). The light guide display assembly 300 may include components related to… Figure 2A The light guide display component 200 shown is or Figure 2B The light guide display assembly 250 shown includes elements, structures, and / or functions that are identical or similar to those in the above text. A description of identical or similar elements, structures, and / or functions can be found in conjunction with the preceding text. Figure 2A or Figure 2B The description presented.

[0081] like Figure 3 As shown, the light guide display assembly 300 may include a light source assembly 305, a light guide 310, and a controller 315. The light source assembly, light guide, and controller may include components respectively located in… Figure 2A and Figure 2BThe light source assembly 205, light guide 210, and controller 215 shown herein have similar or identical elements, structures, and / or functions. The light source assembly 305 may include a light source 320 configured to generate image light 350 (representing a virtual image or display image) having a predetermined field of view (FOV) (e.g., equal to or greater than 40°). The light source assembly 305 may output image light 350 with predetermined FOV in multiple portions (e.g., a first portion and a second portion) with orthogonal polarization, wherein each portion corresponds to a portion of the FOV. For example, the light source assembly 305 may output a first light 353 (or first input light 353) corresponding to a first portion of the FOV (referred to as the first input FOV) and a second light 354 (or second input light 354) corresponding to a second portion of the FOV (referred to as the second input FOV). The first light 353 with the first input FOV and the second light 354 with the second input FOV may propagate from the light source assembly 305 toward the light guide 310 in different non-parallel directions, such as... Figure 3 As shown. The first beam 353 and the second beam 354 can have orthogonal polarization. Figure 3 In the yz cross-sectional view shown, a first ray 353 with a first input FOV can be defined by first rays 353a and 353b. For example, first ray 353a can be the rightmost ray of first ray 353, and first ray 353b can be the leftmost ray of first ray 353. A second ray 354 with a second input FOV can be defined by second rays 354a and 354b. For example, second ray 354a can be the leftmost ray of second ray 354, and second ray 354b can be the rightmost ray of second ray 354. In some embodiments, second ray 354b (e.g., the rightmost ray of second ray 354) and first ray 353b (e.g., the leftmost ray of first ray 353) can substantially overlap each other. Figure 3 In the yz cross-sectional view shown, the second ray 354b and the first ray 353b are represented by the same dashed line. The controller 315 can control various components included in the light guide display assembly 300, such as the light source assembly 305.

[0082] The light guide 310 can be configured to receive a first light 353 and a second light 354 propagating from the light source assembly 305 in different directions. The light guide 310 can be coupled to one or more coupling elements. In some embodiments, each coupling element can be polarization-selective. In some embodiments, each coupling element may include one or more polarization-selective gratings. For the purposes of discussion, each coupling element may be referred to as a coupling grating. It should be understood that in other embodiments, non-grating structures can be used as coupling elements. Figure 3In the illustrated embodiment, the light guide 310 can be coupled to a first coupling grating 335-1 and a second coupling grating 335-2, which can be configured to couple a first light 353 and a second light 354 with orthogonal polarizations into the light guide 310 via diffraction, respectively. Each of the coupling gratings 335-1 and 335-2 can be a transmission grating or a reflection grating. The first coupling grating 335-1 can couple the first light 353 into the light guide 310 via diffraction as a first TIR propagation light 355, and the second coupling grating 335-2 can couple the second light 354 into the light guide 310 via diffraction as a second TIR propagation light 356. For illustrative purposes, Figure 3 A first TIR propagating ray 355a of a first TIR propagating light 355 and a second TIR propagating ray 356a of a second TIR propagating light 356 are shown. A first coupling grating 335-1 can couple the first ray 353a into the light guide 310 as the first TIR propagating ray 355a. A second coupling grating 335-2 can couple the second ray 354a into the light guide 310 as the second TIR propagating ray 356a. The TIR propagating rays of the first ray 353b and the second ray 354b are not shown in the diagram. Figure 3 Draw in the middle.

[0083] The light guide 310 can also be coupled to one or more coupling elements. In some embodiments, each coupling element can be polarization selective. In some embodiments, each coupling element may include one or more polarization-selective gratings. For the purposes of discussion, each coupling element may be referred to as a coupling grating. It should be understood that in other embodiments, non-grating structures can be used as coupling elements. Figure 3 In the illustrated embodiment, the light guide 310 may be coupled to a first coupling grating 345-1 and a second coupling grating 345-2. Each of the coupling gratings 345-1 and 345-2 may be a transmissive grating or a reflective grating. The first coupling grating 345-1 and the second coupling grating 345-2 may be configured to couple a first TIR propagating light 355 and a second TIR propagating light 356 from the light guide 310 via diffraction, respectively, along different non-parallel directions. The first coupling grating 345-1 may be configured to couple the first TIR propagating light 355 from the light guide 310 as a first output light 357 defined by first output rays 357a and 357b. The second coupling grating 345-2 may be configured to couple the second TIR propagating light 356 from the light guide 310 as a second output light 358 defined by second output rays 358a and 358b.

[0084] In some embodiments, a first output light 357 may correspond to a first output FOV, and a second output light 358 may correspond to a second output FOV. The first output FOV may correspond to an angular region defined by the first output light rays 357a and 357b. The second output FOV may correspond to an angular region defined by the second output light rays 358a and 358b. That is, the first coupling grating 335-1, the light guide 310, and the first coupling grating 345-1 may be configured to provide a first output FOV at the eye-friendly area of ​​the light guide display assembly 300. The second coupling grating 335-2, the light guide 310, and the second coupling grating 345-2 may be configured to provide a second output FOV at the eye-friendly area of ​​the light guide display assembly 300. The first output FOV and the second output FOV may be substantially non-overlapping. In some embodiments, the first output FOV and the second output FOV may be substantially non-overlapping consecutive FOVs (e.g., 0° to +50°, 0° to -50°). The combination of the first output FOV and the second output FOV can be substantially greater than each of the first output FOV and the second output FOV. In some embodiments, the combination of the first output FOV and the second output FOV can be greater than the first input FOV and the second input FOV of the first input light 353, or it can be greater than a predetermined FOV of the image light 350.

[0085] In some embodiments, the first TIR propagating light 355 may correspond to a first intermediate FOV, which is smaller than the first input FOV of the first input light 353, and the second TIR propagating light 356 may correspond to a second intermediate FOV, which is smaller than the second input FOV of the second input light 354. The combination of the first output FOV of light 357 and the second output FOV of light 358 at the output side of the light guide display component 300 may be greater than the combination of the first intermediate FOV and the second intermediate FOV.

[0086] In some embodiments, a first coupling grating 345-1 can be configured to couple a first TIR propagation ray 355a from the light guide 310 to serve as a first output ray 357a at a first output angle. A second coupling grating 345-2 can be configured to couple a second TIR propagation ray 356a from the light guide 310 to serve as a second output ray 358a at a second output angle. In some embodiments, the first output angle and the second output angle can have the same absolute value and opposite signs, such as opposite output angles +θ and -θ. In some embodiments, the first output angle and the second output angle can have different absolute values ​​and opposite signs (e.g., +θ1 and -θ2, where θ1 and θ2 have different values). In some embodiments, a first coupling grating 335-1 can be configured to couple a first ray 353b into the light guide 310, and a first coupling grating 345-1 can be configured to couple the first ray 353b from the light guide 310 to serve as a first output ray 357b. In some embodiments, the second coupling grating 335-1 may be configured to couple the second ray 354b into the light guide 310, and the second coupling grating 345-1 may be configured to couple the second ray 354b out of the light guide 310 as a second output ray 358b. In some embodiments, the first output ray 357b and the second output ray 358b may substantially overlap each other.

[0087] It should be noted that when light is diffracted from the light guide, the output angle of the output light is also called the diffraction angle. The diffraction angle refers to the angle formed by the diffracted ray and the normal to the surface of the coupling grating (in some embodiments, the normal to the surface of the coupling grating may be parallel to the normal to the surface of the light guide to which the coupling grating is coupled). In this disclosure, the diffraction angle can be defined as a positive or negative angle based on the positional relationship between the diffracted ray and the normal to the surface of the coupling grating. For example, as... Figure 3 As shown, when the diffracted ray is in a clockwise direction from the normal, the diffraction angle can be defined as a positive angle, while when the diffracted ray is in a counterclockwise direction from the normal, the diffraction angle can be defined as a negative angle.

[0088] In conventional light guide display components, the propagation angle of the TIR path inside the light guide corresponds one-to-one with the output angle of the output light coupled from the light guide, regardless of the polarization state of the TIR propagating light. That is, the propagation angle of the TIR path corresponds to a single output angle of the light coupled from the light guide, regardless of the polarization state of the TIR propagating light. The propagation angle is determined by the refractive index of the light guide. Therefore, the field of view (FOV) provided by the light guide (or light guide display component) can be determined by the refractive index of the light guide. Figure 3In the light guide display assembly 300 shown, by utilizing polarization-selective coupling gratings 335-1, 335-2 and coupling gratings 345-1, 345-2, the same propagation angle of the TIR path within the light guide 310 can correspond to two different output angles (e.g., two diffraction angles with opposite signs). For example, a first TIR propagation ray 355a and a second TIR propagation ray 356a with substantially the same propagation angle of the TIR path can be diffracted by coupling gratings 345-1 and 345-2, respectively, to serve as a first output ray 357a and a second output ray 358a, wherein the first output ray 357a and the second output ray 358a have output angles (e.g., diffraction angles) with opposite signs. Therefore, when the light guides included in the light guide display assembly 300 and conventional light guide display assemblies are made of materials with the same or similar refractive indices, the FOV provided by the light guide display assembly 300 can be enlarged or extended (e.g., doubled) compared to conventional light guide display assemblies. Alternatively or additionally, the disclosed light guide display assembly 300 can provide the same or similar FOV by using a light guide made of a material with a lower refractive index, compared to conventional light guide display assemblies.

[0089] In some embodiments, each of the coupling gratings 335-1 and 335-2 may be disposed on the first surface 310-1 or the second surface 310-2 of the light guide 310. For example, in some embodiments, the coupling gratings 335-1 and 335-2 may be disposed side-by-side or in a stacked configuration on the first surface 310-1 or the second surface 310-2 of the light guide 310. Each of the coupling gratings 345-1 and 345-2 may be disposed on the first surface 310-1 or the second surface 310-2 of the light guide 310. For example, in some embodiments, the coupling gratings 345-1 and 345-2 may be disposed side-by-side or in a stacked configuration on the first surface 310-1 or the second surface 310-2 of the light guide 310. For illustrative purposes, Figure 3The diagram shows coupling gratings 335-1 and 335-2 stacked on the second surface 310-2 of the light guide 310, and coupling gratings 345-1 and 345-2 stacked on the first surface 310-1 of the light guide 310. In some embodiments, coupling gratings 335-1 and 335-2 may be disposed on the first surface 310-1, and coupling gratings 345-1 and 345-2 may be disposed on the second surface 310-2. In some embodiments, coupling gratings 335-1 and 335-2 and coupling gratings 345-1 and 345-2 may be disposed on the same surface (e.g., the first surface 310-1 or the second surface 310-2). At least one (e.g., each) of gratings 335-1, 335-2, 345-1, or 345-2 can be a polarization-selective grating configured to primarily (e.g., substantially) diffract polarized light having a predetermined polarization, and primarily (e.g., substantially) transmit polarized light having a polarization different from the predetermined polarization (e.g., orthogonal polarization) with substantially zero diffraction or with negligible diffraction. The predetermined polarizations associated with gratings 335-1, 335-2, 345-1, and 345-2 may be the same or different.

[0090] In some embodiments, coupling gratings 335-1 and 335-2 can be configured to diffract polarized light with orthogonal polarization. For example, the first coupling grating 335-1 can be configured to primarily diffract polarized light with a first polarization and transmit polarized light with a second polarization orthogonal to the first polarization primarily with substantially zero diffraction or with negligible diffraction. The second coupling grating 335-2 can be configured to primarily diffract polarized light with the second polarization and transmit polarized light with a first polarization orthogonal to the second polarization primarily with substantially zero diffraction or with negligible diffraction. In some embodiments, coupling gratings 345-1 and 345-2 can be configured to diffract polarized light with orthogonal polarization (e.g., orthogonally polarized light). Each of the coupling gratings 345-1 and 345-2 can have the same polarization selectivity as a corresponding coupling grating in one of the coupling gratings 335-1 and 335-2. For example, the first output grating 345-1 may have the same polarization selectivity as the first input grating 335-1, and the second output grating 345-2 may have the same polarization selectivity as the second input grating 335-2. The output grating 345-1 may be configured to primarily diffract polarized light with a first polarization, and to transmit polarized light with a second polarization orthogonal to the first polarization primarily with substantially zero diffraction or with negligible diffraction. The output grating 345-2 may be configured to primarily diffract polarized light with the second polarization, and to transmit polarized light with a first polarization orthogonal to the second polarization primarily with substantially zero diffraction or with negligible diffraction. In some embodiments, the first output grating 345-1 may have the same polarization selectivity as the second input grating 335-2, and the second output grating 345-2 may have the same polarization selectivity as the first input grating 335-1.

[0091] In some embodiments, at least one (e.g., each) of gratings 335-1, 335-2, 345-1, or 345-2 can be a polarization-selective grating, which can be configured to primarily diffract polarized light having a predetermined polarization and transmit polarized light with different (e.g., orthogonal) polarizations primarily with substantially zero diffraction or with negligible diffraction. For example, at least one (e.g., each) of gratings 335-1, 335-2, 345-1, or 345-2 can be a circular polarization-selective grating, which can be configured to primarily diffract circularly polarized light having a predetermined axial rotation and transmit circularly polarized light having an axial rotation opposite to the predetermined axial rotation primarily with substantially zero diffraction or with negligible diffraction. Coupled gratings 335-1 and 335-2 can be configured to diffract circularly polarized light with opposite axial rotations. For example, the first coupling grating 335-1 can be configured to diffract circularly polarized light having a first predetermined directional rotation (e.g., left-handed or right-handed), and the second coupling grating 335-2 can be configured to diffract circularly polarized light having a second predetermined directional rotation (e.g., right-handed or left-handed) opposite to the first predetermined directional rotation. The coupling gratings 345-1 and 345-2 can also be configured to diffract circularly polarized light having opposite directional rotations. For example, the first coupling grating 345-1 can be configured to diffract light having the first predetermined directional rotation, and the second coupling grating 345-2 can be configured to diffract light having a second predetermined directional rotation opposite to the first predetermined directional rotation. In some embodiments, each of the coupling gratings 335-1 and 335-2 may include a transmissive PVH or a reflective PVH. In some embodiments, each of the coupling gratings 345-1 and 345-2 may include a transmissive PVH or a reflective PVH. Various combinations of transmissive PVH and / or reflective PVH may be included in, or implemented as, coupling gratings 335-1 and 335-2 and coupling gratings 345-1 and 345-2.

[0092] The light source assembly 305 may include a light source (e.g., an electronic display) 320 and a light adjustment system 325. The light source assembly 305 may include... Figure 3 Other components not shown. The light source 320 can be... Figure 2A and Figure 2B The embodiment of the light source 220 shown (or may be similar to the light source 220), and the light adjustment system 325 may be... Figure 2A and Figure 2BAn embodiment of the light conditioning system 225 shown is (or may be similar to) light conditioning system 225. In some embodiments, the image light 350 may be unpolarized or polarized. In some embodiments, the image light 350 may be divergent light. The light conditioning system 325 may be configured to receive the image light 350 from the light source 320 and process the image light 350 to output a first light 353 and a second light 354 configured with desired characteristics. The light conditioning system 325 may include suitable optical elements configured to process the image light 350. The optical path of the light 350 propagating in the light conditioning system 325 is not... Figure 3 As shown in the diagram, light 350 can propagate in the light conditioning system 325 via any suitable optical path.

[0093] In some embodiments, the light adjustment system 325 may include a guiding element (not shown) configured to guide different portions of the image light 350 corresponding to different portions of the field of view (FOV) in different propagation directions. For example, the guiding element may be configured to guide a first portion of the image light 350 in a first propagation direction and a second portion of the image light 350 in a second propagation direction different from the first propagation direction. In some embodiments, the light adjustment system 325 may include a polarization conversion element 322 configured to polarize the image light 350 and output two orthogonally polarized lights. In some embodiments, the polarization conversion element 322 may include one or more linear polarizers, one or more circular polarizers, one or more switchable waveplates (such as one or more switchable half-waveplates), one or more switchable quarter-waveplates, or combinations thereof. In some embodiments, the controller 315 may control the operating state of the polarization conversion element 322 (e.g., a switched state or a non-switched state). In some embodiments, the light adjustment system 325 may also include a collimator 321 (e.g., a collimating lens) configured to collimate the image light 350. The guiding element may be positioned appropriately within the light adjustment system 325. In some embodiments, a guiding element may be disposed between the polarization conversion element 322 and the light source 320. In some embodiments, a guiding element may be disposed between the polarization conversion element 322 and the collimator 321. In some embodiments, a guiding element may be disposed between the collimator 321 and the light guide 310. In some embodiments, the guiding element may be omitted.

[0094] In some embodiments, the light source assembly 305 may output the first light 353 and the second light 354 simultaneously during the same time period (i.e., concurrently) (e.g., during the same display frame (or the same subframe) of the display image generated by the light source 320). In some embodiments, the light source assembly 305 may output the first light 353 and the second light 354 in a temporal sequence. For example, the display frame of the display image generated by the light source 320 may include two consecutive subframes. The controller 315 may control the light source assembly 305 to output the first light 353 having a first input FOV (corresponding to a first portion of a predetermined FOV of the image light 350) in the first subframe and the second light 354 having a second input FOV (corresponding to a second portion of a predetermined FOV of the image light 350) in the second subframe. The first subframe and the second subframe may be two consecutive subframes of the display frame. In some embodiments, the light source 320 may be coupled to an optical switch that may be configured to transmit the first light 351 and block the second light 352 in the first subframe, and to transmit the second light 352 and block the first light 351 in the second subframe. In some embodiments, the optical switch may be controlled by the controller 315.

[0095] exist Figure 3 In the illustrated embodiment, reflective PVH gratings are used as examples of coupling gratings 335-1 and 335-2 and coupling gratings 345-1 and 345-2. Coupling gratings 335-1 and 335-2 can be configured to primarily back-diffract circularly polarized light with opposite cycloidium. Coupling gratings 345-1 and 345-2 can be configured to primarily back-diffract circularly polarized light with opposite cycloidium. For purposes of discussion, coupling gratings 345-1 and 345-2 can each have the same polarization selectivity as coupling gratings 335-1 and 335-2. For example, the first light 353 propagating toward coupling grating 335-1 can be RHCP light, and the second light 354 propagating toward coupling grating 335-2 can be LHCP light. Each of the input grating 335-1 and the output grating 345-1 can be configured to primarily diffract RHCP light backward as RHCP light and primarily transmit LHCP light with substantially zero diffraction or with negligible diffraction as LHCP light. Each of the input grating 335-2 and the output grating 345-2 can be configured to primarily diffract LHCP light backward as LHCP light and primarily transmit RHCP light with substantially zero diffraction or with negligible diffraction as RHCP light.

[0096] Reference Figure 3The coupling grating 335-1 can couple a first light 353 (e.g., RHCP light) into the light guide 310 via diffraction to serve as a TIR propagation light 355 (e.g., RHCP light), and transmit a second light 354 (e.g., LHCP light) toward the coupling grating 335-2 with substantially zero diffraction or with negligible diffraction. The coupling grating 335-2 can couple the second light 354 (e.g., LHCP light) into the light guide 310 via diffraction to serve as a TIR propagation light 356 (e.g., LHCP light). For the sake of simplicity, Figure 3 Only the optical paths of one ray 355a from TIR propagation light 355 (e.g., RHCP light) and one ray 356a from TIR propagation light 356 (e.g., LHCP light) are shown. TIR propagation light 355 (e.g., RHCP light) and TIR propagation light 356 (e.g., LHCP light) can propagate via TIR within the light guide 310 toward coupling gratings 345-1 and 345-2.

[0097] In some embodiments, when these TIR propagating lights propagate inside the light guide 310, the polarization of the TIR propagating light 355 (e.g., RHCP light) and the polarization of the TIR propagating light 356 (e.g., LHCP light) may not be changed. In some embodiments, when these TIR propagating lights propagate inside the light guide 310, the polarization of at least one of the TIR propagating lights 355 (e.g., RHCP light) or the TIR propagating light 356 (e.g., LHCP light) may be changed, for example, after total internal reflection at the inner surface of the light guide 310, and may be depolarized. In some embodiments, the light guide 310 may include one or more polarization correction films 330 disposed adjacent to the light guide 310 or disposed on one or more surfaces (e.g., one or two outer surfaces) of the light guide 310. In some embodiments, the polarization correction film 330 may be configured to maintain the polarization state of the TIR propagating light 355 and / or the polarization state of the TIR propagating light 356 when the TIR propagating light 355 and / or the TIR propagating light 356 propagate inside the light guide 310. For example, the polarization correction film 330 can be configured such that when TIR propagating lights 355 and 356 propagate inside the light guide 310, the polarization correction film 330 compensates for the depolarization of at least one of the TIR propagating lights 355 or 356, thereby maintaining the polarization of at least one of the TIR propagating lights 355 or 356. Figure 3 In the embodiment shown, the polarization correction film 330 can be configured such that when the TIR propagating light 355 and 356 propagate inside the light guide 310, the polarization correction film 330 maintains the right-hand circular polarization of the TIR propagating light 355 and the left-hand circular polarization of the TIR propagating light 356.

[0098] Coupling gratings 345-1 and 345-2 can be configured to primarily diffract TIR propagating light 355 and 356 backward from light guide 310 in different directions, thereby replicating and expanding the FOV of image light 350. Coupling grating 345-1 can be configured to couple TIR propagating light 355 (e.g., RHCP light) from light guide 310 via diffraction as a first output light 357 (e.g., RHCP light) with a first diffraction angle, and to transmit TIR propagating light 356 (e.g., LHCP light) toward coupling grating 345-2 with substantially zero diffraction or negligible diffraction. Coupling grating 345-2 can be configured to couple TIR propagating light 356 (e.g., LHCP light) from light guide 310 via diffraction as a second output light 358 (e.g., LHCP light) with a second diffraction angle different from the first diffraction angle. In some embodiments, the first output light 357 may correspond to a first output FOV, and the second output light 358 may correspond to a second output FOV. In some embodiments, the coupling grating 335-1, the light guide 310, and the coupling grating 345-1 may be configured to provide a first output FOV at the eye-friendly region of the light guide display assembly 300. The coupling grating 335-2, the light guide 310, and the coupling grating 345-2 may be configured to provide a second output FOV at the eye-friendly region of the light guide display assembly 300. The first output FOV and the second output FOV may be substantially non-overlapping. In some embodiments, the first output FOV and the second output FOV may be substantially non-overlapping consecutive FOVs (e.g., 0° to +50°, 0° to -50°). The combination of the first output FOV and the second output FOV at the output side of the light guide 310 may be substantially greater than each of the first output FOV and the second output FOV. The combination of the first output FOV and the second output FOV at the output side of the light guide 310 can be greater than the predetermined FOV of the image light 350 emitted by the light source 320, or greater than the combination of the first input FOV of the first input light 353 and the second input FOV of the second input light 354 at the input side of the light guide 310.

[0099] In some embodiments, when the controller 315 controls the light source assembly 305 to output a first light 353 having a first input FOV and a second light 354 having a second input FOV during the same subframe (e.g., simultaneously), the coupling elements 345-1 and 345-2 can couple the first light 353 (i.e., 355 when in the light guide 310) and the second light 354 (i.e., 356 when in the light guide 310) from the light guide 310 during the same subframe to serve as the first output light 357 and the second output light 358. When the controller 315 controls the light source assembly 305 to output a first light 353 with a first input FOV and a second light 354 with a second input FOV during consecutive subframes (e.g., the first subframe and the second subframe), the coupling elements 345-1 and 345-2 can couple the first light 353 (i.e., 355 when in the light guide 310) and the second light 354 (i.e., 356 when in the light guide 310) from the light guide 310 during consecutive subframes to serve as the first output light 357 and the second output light 358.

[0100] In some embodiments, the input grating and the output grating can be transmissive PVH gratings. Figure 4 A schematic diagram is shown of an optical device or optical system 400 configured to provide an extended field of view (FOV) according to another embodiment of this disclosure. The optical system 400 may also be referred to as a light guide display assembly 400. Figure 4 The light guide display component 400 shown may include, with Figure 2A The light guide display component 200 shown Figure 2B The light guide display assembly 250 shown and Figure 3 The light guide display assembly 300 shown includes elements, structures, and / or functions that are identical or similar to those in the original. Descriptions of identical or similar elements, structures, or functions can be found in conjunction with [the original text]. Figure 2A , Figure 2B or Figure 3 The above description is presented.

[0101] like Figure 4 As shown, the light guide display assembly 400 may include a light source assembly 405, a light guide 410, and a controller 415. The light source assembly 405, the light guide 410, and the controller 415 may each include components related to... Figure 3 The light source assembly 405, light guide 410, and controller 415 shown have the same or similar elements, structures, and / or functions. In some embodiments, the light source assembly 405, light guide 410, and controller 415 may include elements, structures, and / or functions that are identical or similar to those of the light source assembly 305, light guide 410, and controller 415. Figure 2A and Figure 2B The light source assembly 205, light guide 210 and controller 215 shown have the same or similar elements, structures and / or functions.

[0102] The light source assembly 405 may include a light source 420 and a light adjustment system 425, the light adjustment system including a polarization conversion element 422 and a collimator 421, and the light source and the light adjustment system can be coupled with... Figure 3 The light source 320 and the light adjustment system 325 (including polarization conversion element 322 and collimator 321) shown are either Figure 2A and Figure 2B The light source 220 and light adjustment system 225 shown are similar. Descriptions of the same or similar components, structures, and / or functions can be found in conjunction with... Figure 2A , Figure 2B or Figure 3 The above description is presented. Controller 415 can control various components included in the light guide display assembly 400, such as the light source assembly 405.

[0103] In some embodiments, the light source 420 may generate image light 450 (representing a virtual image or a displayed image) corresponding to a displayed image. Image light 450 may be associated with a predetermined field of view (FOV). Image light 450 may be unpolarized or polarized. In some embodiments, image light 450 may be divergent light. The light conditioning system 425 may be configured to receive image light 450 from the light source 420 and process the image light 450 to output a first light 453 (or first input light 453) and a second light 454 (or second input light 454) configured with desired characteristics. For example, the first light 453 may correspond to a first portion of the FOV of the image light 450 (referred to as the first input FOV), and the second light 454 may correspond to a second portion of the FOV of the image light 450 (referred to as the second input FOV). The first light 453 and the second light 454 may have orthogonal polarization. The optical path of the image light 450 propagating in the light conditioning system 425 is not... Figure 4 As shown in the diagram, image light 450 can propagate in the light conditioning system 425 via any suitable optical path.

[0104] exist Figure 4 In the yz cross-sectional view shown, the first ray 453 can be defined by first rays 453a and 453b. For example, first ray 453a can be the rightmost ray of the first ray 453, and first ray 453b can be the leftmost ray of the first ray 453. The second ray 454 can be defined by second rays 454a and 454b. For example, second ray 454a can be the leftmost ray of the second ray 454, and second ray 454b can be the rightmost ray of the second ray 454. In some embodiments, the second ray 454b (e.g., the rightmost ray of the second ray 454) and the first ray 453b (e.g., the leftmost ray of the first ray 453) can substantially overlap each other. Figure 4In the yz cross-sectional diagram shown, the second ray 454b and the first ray 453b are represented by the same dashed line.

[0105] The light guide 410 can be coupled to one or more coupling elements. In some embodiments, each coupling element can be polarization selective. In some embodiments, each coupling element may include one or more polarization-selective gratings. For the purposes of discussion, each coupling element may be referred to as a coupling grating. It should be understood that in other embodiments, non-grating structures can be used as coupling elements. Figure 4 In the illustrated embodiment, the light guide 410 may be coupled to a first coupling grating 435-1 and a second coupling grating 435-2, which are configured to couple light 453 and 454 into the light guide 410 via diffraction, respectively. The first coupling grating 435-1 and the second coupling grating 435-2 may be transmissive PVH gratings, configured to diffract circularly polarized light with orthogonal polarization forward. The light guide 410 may also include one or more coupling elements. In some embodiments, each coupling element may be polarization-selective. In some embodiments, each coupling element may include one or more gratings. For the purposes of discussion, each coupling element may be referred to as a coupling grating. It should be understood that in other embodiments, non-grating structures may be used as coupling elements. Figure 4 In the illustrated embodiment, the light guide 410 can be coupled to a first coupling grating 445-1 and a second coupling grating 445-2. The first coupling grating 445-1 and the second coupling grating 445-2 can be transmissive PVH gratings, which are configured to primarily diffract circularly polarized light with orthogonal polarization forward.

[0106] Each of the output gratings 445-1 and 445-2 can have the same polarization selectivity as a corresponding input grating in the input gratings 435-1 and 435-2. For illustrative and discussion purposes, in Figure 4 In the illustrated embodiment, coupling grating 435-1 and coupling grating 445-1 can be transmissive PVH gratings with the same polarization selectivity, and coupling grating 435-2 and coupling grating 445-2 can be transmissive PVH gratings with the same polarization selectivity. For example, coupling grating 435-1 and coupling grating 445-1 can be configured to primarily diffract RHCP light forward as LHCP light, and primarily transmit LHCP light with substantially zero diffraction or with negligible diffraction. Coupling grating 435-2 and coupling grating 445-2 can be configured to primarily diffract LHCP light forward as RHCP light, and primarily transmit RHCP light with substantially zero diffraction or negligible diffraction.

[0107] For illustrative purposes, Figure 4 The diagram shows coupling gratings 435-1 and 435-2 stacked on the first surface 410-1 of the light guide 410, and coupling gratings 445-1 and 445-2 stacked on the second surface 410-2 of the light guide 410. In some embodiments, the light source assembly 405 and the eye 260 may be arranged on the same side of the light guide 410, and coupling gratings 435-1 and 435-2 may be stacked on the first surface 410-1 of the light guide 410, and coupling gratings 445-1 and 445-2 may be stacked on the same first surface 410-1 of the light guide 410. In some embodiments, although... Figure 4 Not shown, but coupling gratings 435-1 and 435-2 can be arranged side-by-side on the first surface 410-1 of the light guide 410, and coupling gratings 445-1 and 445-2 can be arranged side-by-side on the second surface 410-2 of the light guide 410. When arranged side-by-side, coupling gratings 435-1 and 435-2 and coupling gratings 445-1 and 445-2 can be located on the same surface or different surfaces of the light guide 410. In some embodiments, although Figure 4 Not shown, but Figure 4 The illustrated embodiments may include with Figure 3 The polarization correction film shown is similar to the polarization correction film 330.

[0108] Reference Figure 4 The first light 453 and the second light 454 can be circularly polarized light with opposite polarization. For example, the first light 453 can be RHCP light, and the second light 454 can be LHCP light. In some embodiments, the coupling grating 435-1 can be configured to transmit LHCP light with substantially zero diffraction or with negligible diffraction and diffract RHCP light forward. The coupling grating 435-2 can be configured to transmit RHCP light with substantially zero diffraction or with negligible diffraction and diffract LHCP light forward. Therefore, the coupling grating 435-2 can be configured to transmit the first light 453 (e.g., RHCP light) toward the coupling grating 435-1 with substantially zero diffraction or with negligible diffraction without changing the polarization. The coupling grating 435-1 can be configured to couple the first light 453 (e.g., RHCP light) into the light guide 410 via diffraction as a first TIR propagating light 455 (e.g., LHCP light) with changed polarization. In some embodiments, the coupling grating 435-2 can be configured to couple a second light 454 (e.g., LHCP light) into the light guide 410 via diffraction as a second TIR propagating light 456 (e.g., RHCP light) with altered polarization. When the light 456 (e.g., RHCP light) passes through the coupling grating 435-1, the coupling grating 435-1 can transmit the light 456 with substantially zero diffraction or with negligible diffraction without altering its polarization. For illustrative purposes, Figure 4A first TIR propagating ray 455a of a first TIR propagating light 455 and a second TIR propagating ray 456a of a second TIR propagating light 456 are shown. A first coupling grating 435-1 can couple the first ray 453a into the light guide 410 as the first TIR propagating ray 455a. A second coupling grating 435-2 can couple the second ray 454a into the light guide 410 as the second TIR propagating ray 456a. The TIR propagating rays of the first ray 453b and the second ray 454b are not shown in the diagram. Figure 4 Draw in the middle.

[0109] In some embodiments, the light guide 410 may include one or more polarization correction films disposed on one or more surfaces (e.g., one or more outer surfaces) of the light guide 410. The polarization correction films may be configured to maintain the respective polarizations of the first TIR propagating light 455 (e.g., LHCP light) and the second TIR propagating light 456 (e.g., RHCP light) as the first TIR propagating light 455 (e.g., LHCP light) and the second TIR propagating light 456 (e.g., RHCP light) propagating through the light guide 410 via TIR. In some embodiments, the polarization correction films may be coupled with… Figure 3 The polarization correction film 330 shown is similar.

[0110] Coupling gratings 445-1 and 445-2 can be configured to diffract a first TIR propagating light 455 and a second TIR propagating light 456 forward, thereby replicating and expanding the field of view (FOV) of the image light generated by the light source assembly 405. For example, coupling grating 445-1 can transmit the TIR propagating light 455 (e.g., LHCP light) towards coupling grating 445-2 with substantially zero diffraction or with negligible diffraction without altering the polarization. Coupling grating 445-2 can be configured to couple the TIR propagating light 455 (e.g., LHCP light) from the light guide 410 via diffraction as a first output light 457 (e.g., RHCP light) with altered polarization. Coupling grating 445-1 can couple the TIR propagating light 456 (e.g., RHCP light) from the light guide 410 via diffraction as a second output light 458 (e.g., LHCP light) with altered polarization. The coupling grating 445-2 can transmit the second output light 458 (e.g., LHCP light) with essentially zero diffraction or with negligible diffraction, without changing the polarization.

[0111] exist Figure 4In the illustrated embodiments, the first output light 457 can be defined by first output rays 457a and 457b, and the second output light 458 can be defined by second output rays 458a and 458b. In some embodiments, the second coupling grating 445-2 can be configured to couple the first TIR propagation ray 455a out of the light guide 410 as the first output ray 457a at the first output angle. In some embodiments, the first coupling grating 435-1 can be configured to couple the first ray 453b into the light guide 410, and the second coupling grating 445-2 can be configured to couple the first ray 453b out of the light guide 410 as the first output ray 457b. In some embodiments, the first output light 457 can correspond to a first output FOV. The first output FOV can correspond to the angular region defined by the first output rays 457a and 457b. In some embodiments, the first coupling grating 445-1 may be configured to couple the second TIR propagation ray 456a from the light guide 410 as a second output ray 458a at the second output angle. In some embodiments, the second coupling grating 435-1 may be configured to couple the second ray 454b into the light guide 410, and the first coupling grating 445-1 may be configured to couple the second ray 454b from the light guide 410 as a second output ray 458b. In some embodiments, the second output ray 458 may correspond to a second output FOV. The second output FOV may correspond to an angular region defined by the second output rays 458a and 458b. In some embodiments, the first output angle and the second output angle may have the same absolute value and opposite signs, such as opposite output angles +θ and -θ. In some embodiments, the first output angle and the second output angle may have different absolute values ​​and opposite signs (e.g., +θ1 and -θ2, where θ1 and θ2 have different values). In some embodiments, the first output light 457b and the second output light 458b may substantially overlap each other.

[0112] In conventional light guide display components, the propagation angle within the light guide corresponds one-to-one with the diffraction angle of the output light. Figure 4In the illustrated embodiment, the same propagation angle of the TIR path in light guide 410 can correspond to two different diffraction angles (e.g., two diffraction angles with opposite signs). For example, a first TIR propagation ray 455a and a second TIR propagation ray 456a with substantially the same propagation angle of the TIR path can be diffracted by coupling gratings 445-2 and 445-1, respectively, to serve as a first output ray 457a and a second output ray 458a, wherein the first output ray 457a and the second output ray 458a have output angles (e.g., diffraction angles) with opposite signs. Therefore, when the light guides included in the light guide display assembly 400 and conventional light guide display assemblies are made based on materials with the same or similar refractive indices, the FOV provided by the light guide display assembly 400 can be enlarged or extended (e.g., doubled) compared to conventional light guide display assemblies. Alternatively or additionally, the disclosed light guide display assembly 400 can utilize a light guide 410 made based on a material with a lower refractive index to provide the same or similar FOV compared to conventional light guide display assemblies.

[0113] The first input grating 435-1, light guide 410, and second output grating 445-2 can be configured to provide a first output FOV at the eye-friendly region of the light guide display assembly 400. The second input grating 435-2, light guide 410, and first output grating 445-1 can be configured to provide a second output FOV at the eye-friendly region of the light guide display assembly 400. The first output FOV and the second output FOV may be substantially non-overlapping. In some embodiments, the first output FOV and the second output FOV may be substantially non-overlapping consecutive FOVs (e.g., 0° to +50°, 0° to -50°). The combination of the first output FOV and the second output FOV may be substantially greater than each of the first output FOV and the second output FOV. In some embodiments, the combination of the first output FOV and the second output FOV at the output side of the light guide display assembly 400 may be greater than a predetermined FOV of the image light 450 emitted by the light source 420 at the input side of the light guide display assembly 400 (or a combination of the first input FOV of the first light 453 and the second input FOV of the second light 454). In some embodiments, the first TIR propagating light 455 may correspond to a first intermediate FOV, which is smaller than the first input FOV of the first light 453, and the second TIR propagating light 456 may correspond to a second intermediate FOV, which is smaller than the second input FOV of the second light 454. The combination of the first output FOV and the second output FOV at the output side of the light guide display component 400 may be greater than the combined FOV of the first intermediate FOV and the second intermediate FOV.

[0114] In some embodiments, when the controller 415 controls the light source assembly 405 to output a first light 453 having a first input FOV and a second light 454 having a second input FOV during the same subframe (e.g., simultaneously), the coupling elements 445-1 and 445-2 can couple the first light 453 (i.e., 455 when in the light guide 410) and the second light 454 (i.e., 456 when in the light guide 410) from the light guide 410 during the same subframe to serve as the first output light 457 and the second output light 458. When the controller 415 controls the light source assembly 405 to output a first light 453 with a first input FOV and a second light 454 with a second input FOV during consecutive subframes (e.g., the first subframe and the second subframe), the coupling elements 445-1 and 445-2 can couple the first light 453 (i.e., 455 when in the light guide 410) and the second light 454 (i.e., 456 when in the light guide 410) from the light guide 410 during consecutive subframes to serve as the first output light 457 and the second output light 458.

[0115] Figure 5 A schematic diagram is shown of an optical device or optical system 500 configured to provide an extended field of view (FOV) according to embodiments of the present disclosure. The optical system 500 may also be referred to as a light guide display assembly 500. Figure 5 The light guide display component 500 shown may include, with Figure 2A The light guide display component 200 shown Figure 2B The light guide display component 250 shown Figure 3 The light guide display component 300 shown, or Figure 4 The light guide display assembly 400 shown includes elements, structures, and / or functions that are identical or similar to those in the present invention. Descriptions of identical or similar elements, structures, and / or functions can be found in conjunction with [the relevant documentation]. Figures 2A-2B , Figure 3 or Figure 4 The above description is presented.

[0116] like Figure 5 As shown, the light guide display component 500 may include a light source component 505 and a controller 515, the light source component and the controller may include components related to... Figures 2A-2B The light source assembly 205 and controller 215 shown are shown. Figure 3 The light source assembly 305 and controller 315 shown, or Figure 4 The light source assembly 405 and controller 415 shown have similar or identical components, structures, and / or functions. The light source assembly 505 may include a light source 520 and a light adjustment system 525, which includes a polarization conversion element 522 and a collimator 521. The light source and the light adjustment system can be integrated with… Figure 4The light source 420 and the light adjustment system 425 (including polarization conversion element 422 and collimator 421) shown are illustrated. Figure 3 The light source 320 and the light adjustment system 325 (including polarization conversion element 322 and collimator 321) shown are either Figure 2A and Figure 2B The light source 220 and light adjustment system 225 shown are similar. Descriptions of the same or similar components, structures, and / or functions can be found in conjunction with... Figure 2A , Figure 2B , Figure 3 or Figure 4 The above description is presented. The controller 515 can control various components included in the light guide display assembly 500, such as the light source assembly 505.

[0117] In some embodiments, the light source 520 may generate image light 550 representing a displayed image or virtual image. Image light 550 may be associated with a predetermined field of view (FOV). Image light 550 may be unpolarized or polarized. In some embodiments, image light 550 may be divergent light. The light conditioning system 525 may be configured to receive image light 550 from the light source 520 and process the image light 550 to output a first light 553 (or first input light 553) and a second light 554 (or second input light 554) configured with desired characteristics. For example, the first light 553 may correspond to a first portion of the FOV of the image light 550 (referred to as the first input FOV), and the second light 554 may correspond to a second portion of the FOV of the image light 550 (referred to as the second input FOV). The first light 553 and the second light 554 may have orthogonal polarization. The optical path of the image light 550 propagating in the light conditioning system 525 is not... Figure 5 As shown in the diagram, image light 550 can propagate in the light conditioning system 525 via any suitable optical path.

[0118] exist Figure 5 In the yz cross-sectional view shown, a first ray 553 with a first input FOV can be defined by first rays 553a and 553b. For example, first ray 553a can be the rightmost ray of the first ray 553, and first ray 553b can be the leftmost ray of the first ray 553. A second ray 554 with a second input FOV can be defined by second rays 554a and 554b. For example, second ray 554a can be the leftmost ray of the second ray 554, and second ray 554b can be the rightmost ray of the second ray 554. In some embodiments, second ray 554b (e.g., the rightmost ray of the second ray 554) and first ray 553b (e.g., the leftmost ray of the first ray 553) can substantially overlap each other.

[0119] The light guide display assembly 500 may include a light guide stack 510 having multiple light guides stacked together. Figure 5 Two light guides are shown, namely a first light guide 512 and a second light guide 514, which are stacked together to form a light guide stack 510. Some embodiments may include other suitable numbers of light guides, such as three, four, five, etc. Each of light guides 512 and 514 can be... Figures 2A-2B The light guide 210 shown Figure 3 The light guide 310 shown or Figure 4 The illustrated embodiment of light guide 410 (or may be similar to light guide 210, light guide 310, or light guide 410) shows light having a predetermined field of view (FOV) (e.g., equal to or greater than 40°). Light can be configured to have two portions or components with orthogonal polarization corresponding to different portions of the FOV (e.g., a first light and a second light with orthogonal polarization). The light guide stack 510 can be configured to receive the first light as a first input light and receive the second light as a second input light. The first input light and the second input light may have orthogonal polarization.

[0120] The light guide stack 510 may include one or more coupling elements coupled to one or more light guides. In some embodiments, each coupling element may be polarization selective. In some embodiments, each coupling element may include one or more polarization-selective gratings. For the purposes of discussion, each coupling element may be referred to as a coupling grating. It should be understood that in other embodiments, non-grating structures may be used as coupling elements. Figure 5 In the illustrated embodiment, the light guide stack 510 may include a first polarization-selective coupling grating 535-1 and a second polarization-selective coupling grating 535-2, respectively coupled to light guides 512 and 514. The first polarization-selective coupling grating 535-1 and the second polarization-selective coupling grating 535-2 may be configured to couple a first input light and a second input light to the first light guide 512 and the second light guide 514, respectively, via diffraction. The first input light and the second input light can propagate within their respective light guides at substantially the same propagation angle via TIR. As the first input light and the second input light propagate within their respective light guides via TIR, they can propagate via (e.g., with...) Figure 3 One or more polarization correction films (similar to the polarization correction film 330 shown) maintain the polarization of the first input light and the second input light respectively.

[0121] The light guide stack 510 may further include one or more coupling elements coupled to light guides 512 and 514. In some embodiments, each coupling element may be polarization selective. In some embodiments, each coupling element may include one or more polarization selective gratings. For the purposes of discussion, each coupling element may be referred to as a coupling grating. It should be understood that in other embodiments, non-grating structures may be used as coupling elements. Figure 5In the illustrated embodiment, the light guide stack 510 includes two polarization-selective coupling gratings (i.e., a first coupling grating 545-1 and a second coupling grating 545-2) coupled to light guides 512 and 514, respectively. The first coupling grating 545-1 and the second coupling grating 545-2 can be configured to couple first light and second light out of light guides 512 and 514 in different directions via diffraction, respectively. In some embodiments, each of the coupling gratings 535-1 and 535-2 and each of the coupling gratings 545-1 and 545-2 can be a transmissive grating (e.g., a transmissive PVH) or a reflective grating (e.g., a reflective PVH).

[0122] The light guide stack 510 can be configured to receive a first light 553 as a first input light and a second light 554 as a second input light. In some embodiments, the light guide 512 can be coupled to an input grating 535-1 and an output grating 545-1. Each of the input grating 535-1 and the output grating 545-1 can be disposed at a first surface 512-1 or a second surface 512-2 of the light guide 512. For illustrative purposes, the input grating 535-1 is shown as disposed at the second surface 512-2, and the output grating 545-1 is shown as disposed at the first surface 512-1. The light guide 514 can be coupled to the input grating 535-2 and the output grating 545-2. Each of the input grating 535-2 and the output grating 545-2 can be disposed at a first surface 514-1 or a second surface 514-2 of the light guide 514. For illustrative purposes, coupling grating 535-2 is shown as disposed at the second surface 514-2, and coupling grating 545-2 is shown as disposed at the first surface 514-1. The number of coupling gratings and coupling gratings coupled to light guide 512 or light guide 514 is not limited to one for each type, and can be any suitable number, such as two, three, four, etc. When two or more coupling gratings and / or two or more coupling gratings are coupled to each of light guides 512 and 514, the configuration of these coupling gratings and these coupling gratings can be as follows: Figures 2A-2B , Figure 3 or Figure 4 The constructions shown, or some combination thereof.

[0123] In some embodiments, coupling gratings 535-1 and 535-2 can be Figure 3 The coupling gratings 335-1 and 335-2 shown, or Figure 4 The embodiments of coupling gratings 435-1 and 435-2 shown are (or may be similar to coupling gratings 335-1 and 335-2, or coupling gratings 435-1 and 435-2). The output gratings 545-1 and 545-2 may be... Figure 3The coupling gratings 345-1 and 345-2 shown, or Figure 4 The embodiments of the output gratings 445-1 and 445-2 shown (or may be similar to output gratings 345-1 and 345-2, or output gratings 445-1 and 445-2). In some embodiments, such as Figure 5 As shown, coupling gratings 535-1 and 535-2 can be reflective PVH gratings configured to primarily diffract circularly polarized light with opposite cycloidium backscattering, and coupling gratings 545-1 and 545-2 can be reflective PVH gratings configured to primarily diffract circularly polarized light with opposite cycloidium backscattering. In some embodiments, coupling grating 545-1 can have the same polarization selectivity as coupling grating 535-1, and coupling grating 545-2 can have the same polarization selectivity as coupling grating 535-2. In some embodiments, for wave guiding phenomena occurring in the light guides, light guides 512 and 514 can be separated by an air gap. In some embodiments, the air gap between light guides 512 and 514 can be at least partially filled with a material (e.g., adhesive) with a refractive index lower than that of the light guides.

[0124] In some embodiments, the coupling grating 535-1 can be configured to couple a first light 553 (e.g., RHCP light) into the light guide 512 via diffraction as a first TIR propagation light 555 (e.g., RHCP light) without altering its polarization, and to transmit a second light 554 (e.g., LHCP light) toward the coupling grating 535-2 of the light guide 514 with substantially zero diffraction or negligible diffraction without altering its polarization. The first TIR propagation light 555 (e.g., RHCP light) can propagate toward the coupling grating 545-1 within the light guide 512 via TIR. The coupling grating 535-2 can be configured to couple the second light 554 (e.g., LHCP light) into the light guide 514 via diffraction as a second TIR propagation light 556 (e.g., LHCP light) without altering its polarization. The second TIR propagation light 556 (e.g., LHCP light) can propagate toward the coupling grating 545-2 within the light guide 514 via TIR. For illustrative purposes, Figure 5 A first TIR propagating ray 555a of a first TIR propagating light 555 and a second TIR propagating ray 556a of a second TIR propagating light 556 are shown. A first coupling grating 535-1 can couple the first ray 553a into the light guide 512 as the first TIR propagating ray 555a. A second coupling grating 535-2 can couple the second ray 554a into the light guide 514 as the second TIR propagating ray 556a. The TIR propagating rays of the first ray 553b and the second ray 554b are not shown in the diagram. Figure 5 Draw in the middle.

[0125] In some embodiments, light guides 512 and 514 may include one or more polarization correction films disposed on one or more surfaces (e.g., one or more outer surfaces) of the respective light guides. The polarization correction films may be configured to maintain the polarization of the TIR propagating light 555 (e.g., RHCP light) and the TIR propagating light 556 (e.g., LHCP light) as the first TIR propagating light 555 and the second TIR propagating light 556 propagate within their respective light guides. In some embodiments, the polarization correction films may be coupled with… Figure 3 The polarization correction film 330 shown is similar.

[0126] The coupling grating 545-1 can be configured to couple a first TIR propagating light 555 (e.g., RHCP light) from the light guide 512 via diffraction as a first output light 557 (e.g., RHCP light) without changing its polarization. The first output light 557 can then propagate toward the eye 260 after passing through the coupling grating 545-2 and the light guide 514, without changing its polarization. The coupling grating 545-2 can be configured to couple a second TIR propagating light 556 (e.g., LHCP light) from the light guide 514 via diffraction as a second output light 558 (e.g., LHCP light) propagating toward the eye 260.

[0127] exist Figure 5In the illustrated embodiments, the first output light 557 can be defined by first output rays 557a and 557b, and the second output light 558 can be defined by second output rays 558a and 558b. In some embodiments, the first coupling grating 545-1 can be configured to couple the first TIR propagation ray 555a from the light guide 512 as the first output ray 557a at the first output angle. In some embodiments, the first coupling grating 535-1 can be configured to couple the first ray 553b into the light guide 512, and the first coupling grating 545-1 can be configured to couple the first ray 553b from the light guide 512 as the first output ray 557b. In some embodiments, the first output light 557 can correspond to a first output FOV. The first output FOV can correspond to the angular region defined by the first output rays 557a and 557b. In some embodiments, the second output grating 545-2 may be configured to couple the second TIR propagation ray 556a from the light guide 514 as a second output ray 558a at the second output angle. In some embodiments, the second input grating 535-1 may be configured to couple the second ray 554b into the light guide 514, and the second output grating 545-2 may be configured to couple the second ray 554b from the light guide 514 as a second output ray 558b. In some embodiments, the second output ray 558 may correspond to a second output FOV. The second output FOV may correspond to an angular region defined by the second output rays 558a and 558b. In some embodiments, the first output angle of the first output ray 557a and the second output angle of the second output ray 558a may have the same absolute value and opposite signs, such as opposite output angles +θ and -θ. In some embodiments, the first output angle of the first output ray 557a and the second output angle of the second output ray 558a may have different absolute values ​​and opposite signs (e.g., +θ1 and -θ2, where θ1 and θ2 have different values). In some embodiments, the first output ray 557b and the second output ray 558b may substantially overlap each other.

[0128] In conventional light guide display components, the propagation angle within the light guide corresponds one-to-one with the diffraction angle of the output light. Figure 5In the illustrated embodiment, the same propagation angle of the TIR path in light guides 512 and 514 can correspond to two different diffraction angles (e.g., two diffraction angles with opposite signs). For example, a first TIR propagation ray 555a and a second TIR propagation ray 556a with substantially the same propagation angle of the TIR path can be coupled out of gratings 545-1 and 545-2 for diffraction, to serve as a first output ray 557a at a first output angle and a second output ray 558a at a second output angle, respectively. The first output angle (or diffraction angle) and the second output angle (or diffraction angle) can have the same or different absolute values ​​and have opposite signs. Therefore, the FOV provided by the light guide display assembly 500 can be enlarged or extended (e.g., doubled) compared to conventional light guide display assemblies (including stacked light guides made of materials with the same or similar refractive indices). Alternatively or additionally, the disclosed light guide display assembly 500 (with light guides made of materials with lower refractive indices) can provide the same or similar FOV compared to conventional light guide stacks.

[0129] The first coupling grating 535-1, light guide 512, and first output grating 545-1 can be configured to provide a first output FOV at the eye-friendly region of the light guide display assembly 500. The second coupling grating 535-2, light guide 514, and second output grating 545-2 can be configured to provide a second output FOV at the eye-friendly region of the light guide display assembly 500. The first output FOV and the second output FOV may be substantially non-overlapping. In some embodiments, the first output FOV and the second output FOV may be substantially non-overlapping consecutive FOVs (e.g., 0° to +50°, 0° to -50°). The combination of the first output FOV and the second output FOV may be substantially greater than each of the first output FOV and the second output FOV. In some embodiments, the combination of the first output FOV and the second output FOV at the output side of the light guide display assembly 500 may be greater than a predetermined FOV of the image light 550 emitted by the light source 520 at the input side of the light guide display assembly 500 (or a combination of the first input FOV of the first light 553 and the second input FOV of the second light 554). In some embodiments, the first TIR propagating light 555 may correspond to a first intermediate FOV, which is smaller than the first input FOV of the first light 553, and the second TIR propagating light 556 may correspond to a second intermediate FOV, which is smaller than the second input FOV of the second light 554. The combination of the first output FOV and the second output FOV at the output side of the light guide display component 500 may be greater than the combination of the first intermediate FOV and the second intermediate FOV.

[0130] In some embodiments, when the controller 515 controls the light source assembly 505 to output a first light 553 having a first input FOV and a second light 554 having a second input FOV during the same subframe (e.g., simultaneously), the coupling elements 545-1 and 545-2 can couple the first light 553 (i.e., 555 when it is in the light guide 512 of the light guide stack 510) and the second light 554 (i.e., 556 when it is in the light guide 514 of the light guide stack 510) from the light guides 512 and 514 during the same subframe to serve as the first output light 557 and the second output light 558. When the controller 515 controls the light source assembly 505 to output a first light 553 having a first input FOV and a second light 554 having a second input FOV during consecutive subframes (e.g., the first subframe and the second subframe), the coupling elements 545-1 and 545-2 can respectively couple the first light 553 (i.e., 555 when in the light guide 512) and the second light 554 (i.e., 556 when in the light guide 514) from the light guide 512 and the light guide 514 during consecutive subframes to serve as the first output light 557 and the second output light 558.

[0131] Figure 6A and Figure 6B A schematic diagram is shown of an optical device or optical system 600 configured to provide an extended field of view (FOV) according to another embodiment of the present disclosure. The optical system 600 may also be referred to as a light-guided display assembly 600. Figure 6A and Figure 6B The light guide display component 600 shown may include, with Figure 2A The light guide display component 200 shown Figure 2B The light guide display component 250 shown Figure 3 The light guide display component 300 shown Figure 4 The light guide display component 400 shown, or Figure 5 The light guide display assembly 500 shown includes elements, structures, and / or functions that are identical or similar to those in the present invention. Descriptions of identical or similar elements, structures, and / or functions can be found in conjunction with [the provided text]. Figure 2A , Figure 2B , Figure 3 , Figure 4 or Figure 5 The above description is presented.

[0132] like Figure 6A and Figure 6B As shown, the light guide display component 600 may include a light source component 605, a light guide 610, and a controller 615. The light source component, the light guide, and the controller can be... Figure 2A and Figure 2B The light source assembly 205, light guide 210, and controller 215 shown are... Figure 3The light source assembly 305, light guide 310, and controller 315 shown are... Figure 4 The light source 405, light guide 410, and controller 415 shown are, or Figure 5 The embodiments shown include light source 505, light guide 512, light guide 514, and controller 515 (or may be similar to light source assembly 205, light guide 210, and controller 215; light source assembly 305, light guide 310, and controller 315; light source 405, light guide 410, and controller 415; or light source 505, light guide 512, light guide 514, and controller 515).

[0133] The light source assembly 605 may include a light source 620 and a light adjustment system 625, the light adjustment system including a polarization conversion element 622 and a collimator 621, and the light source and the light adjustment system can be coupled with... Figure 5 The light source 520 and the light adjustment system 525 (including polarization conversion element 522 and collimator 521) shown are illustrated. Figure 4 The light source 420 and the light adjustment system 425 (including polarization conversion element 422 and collimator 421) shown are illustrated. Figure 3 The light source 320 and the light adjustment system 325 (including polarization conversion element 322 and collimator 321) shown are either Figure 2A and Figure 2B The light source 220 and light adjustment system 225 shown are similar. Descriptions of the same or similar components, structures, and / or functions can be found in conjunction with [other descriptions]. Figure 2A , Figure 2B , Figure 3 , Figure 4 or Figure 5 The above description is presented.

[0134] Light with a predetermined field of view (FOV) (e.g., equal to or greater than 40°) can be configured to have two orthogonally polarized portions corresponding to different portions of the FOV (e.g., a first light and a second light with orthogonal polarization). The light source assembly 605 can be configured to output the first and second lights with orthogonal polarization in a time-sequential manner (e.g., during two consecutive subframes of a display frame), which can be achieved by a first polarization switch 623 coupled to the light source 620. Using the first polarization switch 623, the light source assembly 605 can output a first light with a first polarization and a second light with a second polarization during two consecutive subframes, respectively. The first and second polarizations can be orthogonal polarizations. In some embodiments, the first polarization switch 623 can be included in the light conditioning system 625.

[0135] The light guide 610 can be configured to receive first light with a first polarization as first input light during two consecutive subframes, and to receive second light with a second polarization as second input light. The light guide 610 can be coupled to one or more coupling elements. In some embodiments, each coupling element can be polarization-selective. In some embodiments, each coupling element can include one or more gratings. For the purposes of discussion, the coupling element can be referred to as a coupling grating. It should be understood that in other embodiments, non-grating structures can be used as coupling elements. Figure 6A In the illustrated embodiment, two polarization-selective coupling gratings, a first coupling grating 635-1 and a second coupling grating 635-2, are coupled to the light guide 610. The number of coupling gratings is not limited to two and can be any suitable number, such as one, three, four, five, six, etc. The first coupling grating 635-1 and the second coupling grating 635-2 can be configured to couple a first input light and a second input light with orthogonal polarization to the light guide 610 via diffraction during two consecutive subframes, respectively. The first input light and the second input light can propagate within the light guide 610 via TIR during the two consecutive subframes, respectively.

[0136] The light guide 610 can also be coupled to one or more coupling elements. In some embodiments, each coupling element can be polarization selective. In some embodiments, each coupling element may include one or more polarization-selective gratings. For the purposes of discussion, each coupling element may be referred to as a coupling grating. It should be understood that in other embodiments, non-grating structures may be used as coupling elements. Figure 6A In the illustrated embodiment, two output gratings (i.e., the first output grating 645-1 and the second output grating 645-2) are coupled to the light guide 610. Each of the input gratings 635-1 and 635-2 and the output gratings 645-1 and 645-2 can be a transmissive grating (e.g., a transmissive PVH) or a reflective grating (e.g., a reflective PVH).

[0137] A first input light with a first polarization and a second input light with a second polarization can propagate from coupling gratings 635-1 and 635-2 within the light guide 610 towards coupling gratings 645-1 and 645-2 during two consecutive subframes, respectively, as a first TIR propagation light and a second TIR propagation light. In some embodiments, the first TIR propagation light may have a first polarization as an initial polarization, and the second TIR propagation light may have a second polarization as an initial polarization. When the first TIR propagation light and the second TIR propagation light propagate through TIR within the light guide 610, the polarization of the first TIR propagation light and the polarization of the second TIR propagation light may not be maintained (i.e., the polarization of the first TIR propagation light and the polarization of the second TIR propagation light may be changed from their respective initial polarizations). When the first TIR propagation light reaches the first coupling element and / or the second coupling element, the first TIR propagation light may include a first polarization component and a second polarization component. The first polarization component may have a first polarization, and the second polarization component may have a second polarization. Therefore, the first polarization component and the second polarization component may be referred to as orthogonal polarization components. When the second TIR propagating light reaches the first and / or second coupling element, the second TIR propagating light may include a first polarization component and a second polarization component, similar to the case of the first TIR propagating light. Therefore, during each subframe in two consecutive subframes, the two polarization-selective coupling gratings 645-1 and 645-2 can decouple the two orthogonal polarization components of the corresponding TIR propagating light from the optical guide 610 via diffraction to serve as two orthogonal polarized output lights.

[0138] For example, in the first subframe, when the first TIR propagating light reaches the coupling gratings 645-1 and 645-2, the first TIR propagating light may have a first polarization component (e.g., an RHCP component) and a second polarization component (e.g., an LHCP component). The coupling gratings 645-1 and 645-2 may, via diffraction, couple the first polarization component (e.g., the RHCP component) and the second polarization component (e.g., the LHCP component) of the first TIR propagating light from the light guide 610 as the first RHCP output light and the first LHCP output light, respectively. In the second subframe, when the second TIR propagating light reaches the coupling gratings 645-1 and 645-2, the second TIR propagating light may have a first polarization component (e.g., an RHCP component) and a second polarization component (e.g., an LHCP component). Coupling gratings 645-1 and 645-2 can decouple the first polarization component (e.g., RHCP component) and the second polarization component (e.g., LHCP component) of the second TIR propagating light from the light guide 610 via diffraction to serve as the second RHCP output light and the second LHCP output light, respectively. In each subframe, the two orthogonally polarized output lights can form two images, one of which can be the main image and the other can be a phantom image. The phantom image can be suppressed or eliminated via a second polarization switch 630 and an absorptive polarizer 640 disposed between the coupling gratings 645-1 and 645-2 (or the light guide 610) and the eye 260.

[0139] The controller 615 can control various components included in the light guide display assembly 600, such as the light source assembly 605, the first polarization switch 623, and the second polarization switch 630. For example, the controller 615 can control the operating state of the first polarization switch 623 and the second polarization switch 630 to synchronize these operating states. That is, the operating state of the second polarization switch 630 (e.g., a switching state or a non-switching state) can be controlled to be the same as the operating state of the first polarization switch 623. When the controller 615 controls the first polarization switch 623 to change its operating state, the controller 615 can simultaneously control the second polarization switch 630 to change its operating state to match the operating state of the first polarization switch 623.

[0140] In some embodiments, refer to Figure 6A and Figure 6BThe light source 620 can emit image light 650 (representing a virtual image or a displayed image) with a predetermined FOV (e.g., equal to or greater than 40°), which corresponds, for example, to a displayed image with a predetermined FOV (e.g., equal to or greater than 40°). The image light 650 can be unpolarized or polarized. In some embodiments, the image light 650 can be divergent light. The image light 650 with a predetermined FOV (e.g., equal to or greater than 40°) can be configured to correspond to two portions of the image light emitted by the light source 620, namely 651 (in...) Figure 6A (shown in) and 652 (in Figure 6B (As shown in the diagram) (e.g., first light 651 and second light 652). Controller 615 can control light source 620 to emit two lights 651 and 652 corresponding to different portions of the field of view (FOV) in a time-sequential manner. For example, a display frame of a display image generated by light source 620 may include two consecutive subframes, namely a first subframe and a second subframe. Controller 615 can control light source 620 to emit light 651 (as shown in the diagram) during the first subframe, corresponding to a first portion of the FOV of image light 650 (referred to as the first input FOV). Figure 6A As shown), and during the second subframe, light 652 corresponding to the second portion of the FOV of image light 650 (referred to as the second input FOV) is emitted (as shown). Figure 6B (As shown).

[0141] The light conditioning system 625 can be configured to receive light 651 from the light source 620 during a first subframe and process the light 651 to output a first light 653 (or a first input light 653), and to receive light 652 from the light source 620 during a second subframe and process the light 652 to output a second light 654 (or a second input light 654). In some embodiments, the characteristics of light 653 and 654 can be similar to those of light 654. Figure 3 The characteristics of light 353 and light 354 are shown. For example, first light 653 may correspond to a first portion of the FOV of image light 650 (referred to as the first input FOV), and second light 654 may correspond to a second portion of the FOV of image light 650 (referred to as the second input FOV). First light 653 and second light 654 may have orthogonal polarization. The optical path of image light 650 propagating in the light conditioning system 625 is not... Figure 6A and Figure 6B As shown in the diagram. Image light 650 can propagate in the light conditioning system 625 via any suitable optical path. Figure 6A In the yz cross-sectional diagram shown, the first ray 653 can be defined by first rays 653a and 653b. For example, first ray 653a can be the rightmost ray of the first ray 653, while first ray 653b can be the leftmost ray of the first ray 653. Figure 6BIn the yz cross-sectional diagram shown, the second ray 654 can be defined by second rays 654a and 654b. For example, second ray 654a can be the leftmost ray of the second ray 654, while second ray 654b can be the rightmost ray of the second ray 654.

[0142] In some embodiments, the light adjustment system 625 may include a first polarization switch 623, which may be an active element configured to maintain the polarization of incident light or switch the polarization of incident light to orthogonal polarization depending on the operating state of the first polarization switch 623 (e.g., switched or unswitched state). A controller 615 may be configured to control the operating state of the first polarization switch 623. In some embodiments, the first polarization switch 623 may be configured to maintain the directional rotation of circularly polarized incident light or switch the directional rotation of circularly polarized incident light to the opposite directional rotation depending on the operating state of the first polarization switch 623 (e.g., switched or unswitched state). In some embodiments, the light adjustment system 625 may further include a polarization conversion element 622, which is configured to polarize the image light 650 before it is incident on the first polarization switch 623. In some embodiments, the polarization conversion element 622 may be a switchable waveplate as described above in conjunction with polarization conversion element 322. The controller 615 can control the operating state of the switchable polarization conversion element 622 (e.g., switched state or non-switched state).

[0143] The light adjustment system 625 may also include a collimator 621 (e.g., a collimating lens). For illustrative purposes, Figure 6A and Figure 6B A first polarization switch 623 is shown disposed between the polarization conversion element 622 and the collimator 621. Although not shown, in some embodiments, the polarization conversion element 622 may be disposed between the first polarization switch 623 and the collimator 621. The polarization conversion element 622 may be configured to polarize light output from the first polarization switch 623 to a predetermined polarization, such as circular polarization. In some embodiments, the polarization conversion element 622 may be omitted. In some embodiments, the first polarization switch 623 may not be part of the light source assembly 605 and may be disposed between the light source assembly 605 and the light guide 610. In some embodiments, the first polarization switch 623 may not be part of the light source assembly 605. Instead, the first polarization switch 623 may be part of the light guide 610. For example, in some embodiments, the first polarization switch 623 may be disposed on the surface of the light guide 610.

[0144] In some embodiments, the first polarization switch 623 may include a switchable half-wave plate (“SHWP”). For example, the light source 620 may be configured to emit circularly polarized light having a first directionality toward the first polarization switch 623. In some embodiments, the polarization conversion element 622 may be omitted. The controller 615 may control the first polarization switch 623 (e.g., the SHWP) to operate in a non-switching state to maintain the directionality of the circularly polarized light. The controller 615 may also control the first polarization switch 623 (e.g., the SHWP) to operate in a switching state to switch the directionality of the circularly polarized light from the first directionality to a second directionality opposite to the first directionality.

[0145] In some embodiments, the light source 620 may be configured to emit linearly polarized light, and the polarization conversion element 622 may include a quarter-wave plate (“QWP”) configured to convert the linearly polarized light into circularly polarized light having a first directionality. In some embodiments, the light source 620 may be configured to emit unpolarized light, and the polarization conversion element 622 may include a linear polarizer and a QWP. The linear polarizer may be configured to convert the unpolarized light into linearly polarized light. The QWP may be configured to convert the linearly polarized light into circularly polarized light having a first directionality. In some embodiments, when the light source 620 emits unpolarized light, a circular polarizer may be used instead of the combination of the linear polarizer and the QWP in the polarization conversion element 622.

[0146] In some embodiments, the light guide 610 may be coupled to one or more coupling elements. In some embodiments, each coupling element may be polarization selective. In some embodiments, each coupling element may include one or more gratings. For the purposes of discussion, each coupling element may be referred to as a coupling grating. It should be understood that in other embodiments, non-grating structures may be used as coupling elements. Figure 6A Two coupling gratings (i.e., a first coupling grating 635-1 and a second coupling grating 635-2) are shown coupled to a light guide 610. Each of the first coupling grating 635-1 and the second coupling grating 635-2 may be disposed at a first surface 610-1 or a second surface 610-2 of the light guide 610. The light guide 610 may be coupled to one or more coupling elements. In some embodiments, each coupling element may be polarization-selective. In some embodiments, each coupling element may include one or more gratings. For the purposes of discussion, each coupling element may be referred to as a coupling grating. It should be understood that in other embodiments, non-grating structures may be used as coupling elements. Figure 6ATwo coupling gratings (i.e., first coupling grating 645-1 and second coupling grating 645-2) are shown coupled to the light guide 610. Each of the first coupling grating 645-1 and the second coupling grating 645-2 can be disposed at either the first surface 610-1 or the second surface 610-2 of the light guide 610. For illustrative purposes, Figure 6A and Figure 6B The diagram shows that coupling gratings 635-1 and 635-2 are stacked on the second surface 610-2 of the light guide 610, and coupling gratings 645-1 and 645-2 are stacked on the first surface 610-1 of the light guide 610.

[0147] The coupling gratings 635-1 and 635-2 can be Figure 3 The coupling gratings 335-1 and 335-2 shown are... Figure 4 The coupling gratings 435-1 and 435-2 shown, or Figure 5 The embodiments of coupling gratings 535-1 and 535-2 shown (or may be similar to coupling gratings 335-1 and 335-2, coupling gratings 435-1 and 435-2, or coupling gratings 535-1 and 535-2). The output gratings 645-1 and 645-2 may be... Figure 3 The coupling gratings 345-1 and 345-2 shown are... Figure 4 The coupling gratings 445-1 and 445-2 shown, or Figure 5 The embodiments of the coupling-out gratings 545-1 and 545-2 shown (or may be similar to coupling-out gratings 345-1 and 345-2, coupling-out gratings 445-1 and 445-2, or coupling-out gratings 545-1 and 545-2). In some embodiments, each of the coupling-in gratings 635-1, 635-2 and each of the coupling-out gratings 645-1 and 645-2 can be a transmissive grating (e.g., a transmissive PVH grating) or a reflective grating (e.g., a reflective PVH grating). Figure 6A and Figure 6B In the illustrated embodiment, coupling gratings 635-1 and 635-2 can be reflective PVH gratings configured to back-diffuse circularly polarized light with orthogonal polarization, and coupling gratings 645-1 and 645-2 can be reflective PVH gratings configured to back-diffuse circularly polarized light with orthogonal polarization. Coupling grating 645-1 can have the same polarization selectivity as coupling grating 635-1, and coupling grating 645-2 can have the same polarization selectivity as coupling grating 635-2.

[0148] In some embodiments, the light guide 610 may be coupled to a second polarization switch 630 and an absorptive polarizer 640 configured to suppress illusory images. The second polarization switch 630 may be disposed between the absorptive polarizer 640 and the light guide 610, and the absorptive polarizer 640 may be disposed between the second polarization switch 630 and the eye 260. The second polarization switch 630 may be an embodiment of (or similar to) the first polarization switch 623, and may be synchronized with the first polarization switch 623. For example, the controller 615 may control both the second polarization switch 630 and the first polarization switch 623 to operate in a switched state during one of the first and second subframes, and in a non-switched state during the other of the first and second subframes. In some embodiments, the second polarization switch 630 may not be synchronized with the first polarization switch 623. For example, the second polarization switch 630 and the first polarization switch 623 may be configured to operate in a switched state during different subframes and in a non-switched state during different subframes. In other words, within a subframe, one of the first polarization switch 623 and the second polarization switch 630 can operate in a switched state, while the other of the first polarization switch 623 and the second polarization switch 630 can operate in a non-switched state. The absorptive polarizer 640 can be configured to block light forming the illusory image by absorption and transmit light forming the main image. In some embodiments, the absorptive polarizer 640 can be a circular polarizer. In some embodiments, the absorptive polarizer 640 can be a linear polarizer, and a QWP can be disposed between the absorptive polarizer 640 and the second polarization switch 630. The QWP can be configured to convert circularly polarized light into linearly polarized light, or vice versa.

[0149] Reference Figure 6ADuring the first subframe of the display frame, light source 620 may output light 651 toward polarization conversion element 622. In some embodiments, light 651 may correspond to a first portion of the field of view (FOV) of image light 650 (referred to as the first input FOV). For illustrative purposes, light 651 may be unpolarized or linearly polarized light. Polarization conversion element 622 may be configured to polarize light 651 into circularly polarized light (e.g., RHCP light). Circularly polarized light (e.g., RHCP light) may propagate toward a first polarization switch 623 (e.g., SHWP). The first polarization switch 623 (e.g., SHWP) may be configured to operate in a non-switching state to transmit circularly polarized light (e.g., RHCP light) without affecting polarization. For example, the first polarization switch 623 (e.g., SHWP) may transmit circularly polarized light (e.g., RHCP light) received from polarization conversion element 622 as circularly polarized light (e.g., RHCP light) without changing polarization. The coupling grating 635-1 can be configured to couple a first light 653 (e.g., RHCP light) into the photoguide 610 via diffraction as a first TIR propagation light 655 (e.g., RHCP light). For illustrative purposes, Figure 6A A first TIR propagation ray 655a is shown. A first coupling grating 635-1 can couple the first ray 653a into the light guide 610 as the first TIR propagation ray 655a. The corresponding TIR propagation ray of the first ray 653b is not shown. Figure 6A Draw in the middle.

[0150] When the first TIR propagating light 655 propagates through the TIR within the light guide 610 toward the coupling gratings 645-1 and 645-2, the initial polarization (e.g., right-hand circular polarization) of the first TIR propagating light 655 may not be maintained (i.e., may be changed). Upon reaching the coupling gratings 645-1 and 645-2, the first TIR propagating light 655 may include a principal portion (or first polarization component) having an initial polarization and a secondary portion (or second polarization component) having a polarization orthogonal to the initial polarization (i.e., changed from the initial polarization). For example, upon reaching the coupling gratings 645-1 and 645-2, the first TIR propagating light 655 may include a principal portion (or first polarization component) as the RHCP component of the first TIR propagating light 655 and a secondary portion (or second polarization component) as the LHCP component of the first TIR propagating light 655. The coupling grating 645-1 can be configured to couple a first polarization component (e.g., an RHCP component) of the first TIR propagating light 655 from the light guide 610 via diffraction as a first output light 661 (e.g., RHCP light), and to transmit a second polarization component (e.g., an LHCP component) of the first TIR propagating light 655 toward the coupling grating 645-2 without diffraction. The coupling grating 645-2 can be configured to couple a second polarization component (e.g., an LHCP component) of the first TIR propagating light 655 from the light guide 610 via diffraction as a second output light 662 (e.g., LHCP light). The first output light 661 and the second output light 662, having orthogonal polarizations, can form two images: a master image formed by the first output light 661 diffracted by the coupling grating 645-1, and a mirrored phantom image formed by the second output light 662 diffracted by the coupling grating 645-2.

[0151] The second polarization switch 630 (e.g., SHWP) can be synchronized with the first polarization switch 623 (e.g., SHWP) to operate in a non-switching state, thereby transmitting light 661 (e.g., RHCP light) and light 662 (e.g., LHCP light) without affecting their respective polarizations. The controller 615 can control the synchronized operation of the second polarization switch 630 and the first polarization switch 623. In some embodiments, the second polarization switch 630 (e.g., SHWP) can be configured to maintain the polarization of light 661 (e.g., RHCP light) and can transmit light 661 (e.g., RHCP light) as light 663 (e.g., RHCP light). Furthermore, the second polarization switch 630 (e.g., SHWP) can be configured to maintain the polarization of light 662 (e.g., LHCP light) and transmit light 662 (e.g., LHCP light) as light 664 (e.g., LHCP light). The polarizer 640 can be configured to transmit light forming the main image and block light forming the illusory image via absorption. In some embodiments, such as Figure 6AAs shown, polarizer 640 can be an absorptive circular polarizer configured to transmit RHCP light and block LHCP light via absorption. Therefore, light 663 (e.g., RHCP light) can pass through polarizer 640 as a first output light 657 (e.g., RHCP light) propagating toward eye 260, and light 664 (e.g., LHCP light) can be blocked by polarizer 640 via absorption. Therefore, eye 260 will not receive light 664. Eye 260 can observe the main image formed by light 661 diffracted by coupling grating 645-1, and can ignore the illusory image formed by light 662 diffracted by coupling grating 645-2.

[0152] Reference Figure 6B During the second subframe of the display frame, light source 620 may output light 652 toward polarization conversion element 622. In some embodiments, light 652 may correspond to a second portion of the field of view (FOV) of image light 650 (referred to as the second input FOV). For illustrative purposes, light 652 may be unpolarized or linearly polarized light. Polarization conversion element 622 may be configured to polarize light 652 into circularly polarized light (e.g., RHCP light). Circularly polarized light (e.g., RHCP light) may propagate toward a first polarization switch 623 (e.g., SHWP). The first polarization switch 623 (e.g., SHWP) may be configured to operate in a switching state to switch the directionality of circularly polarized light (e.g., RHCP light) to the opposite directionality. For example, the first polarization switch 623 (e.g., SHWP) may transmit circularly polarized light (e.g., RHCP light) received from polarization conversion element 622 as circularly polarized light with altered polarization (e.g., LHCP light).

[0153] Since coupling grating 635-1 is configured to back-diffuse RHCP light and transmit LHCP light with substantially zero diffraction or negligible diffraction, the second light 654 (e.g., LHCP light) can pass through coupling grating 635-1 toward coupling grating 635-2. Coupling grating 635-2 can be configured to couple the second light 654 (e.g., LHCP light) to light guide 610 via diffraction as a second TIR propagating light 656 (e.g., LHCP light). For illustrative purposes, Figure 6B A second TIR propagation ray 656a is shown. A second coupling grating 635-2 can couple the second ray 654a into the light guide 610 as the second TIR propagation ray 656a. The corresponding TIR propagation ray 654b is not shown. Figure 6B As shown in the image.

[0154] When the second TIR propagating light 656 propagates through the TIR within the optical guide 610 toward the coupling gratings 645-1 and 645-2, the initial polarization (e.g., left-handed circular polarization) of the second TIR propagating light 656 may not be maintained (i.e., may be changed). Upon reaching the coupling gratings 645-1 and 645-2, the second TIR propagating light 656 may include a principal portion (or first polarization component) having an initial polarization and a secondary portion (or second polarization component) having a polarization orthogonal to the initial polarization. For example, upon reaching the coupling gratings 645-1 and 645-2, the second TIR propagating light 656 may include a principal portion (or first polarization component) as the LHCP component of the second TIR propagating light 656, and a secondary portion (or second polarization component) as the RHCP component of the second TIR propagating light 656. The coupling grating 645-1 can be configured to couple a first polarization component (e.g., an RHCP component) of the second TIR propagating light 656 from the light guide 610 via diffraction as a first (or third) output light 665 (e.g., RHCP light), and to transmit a second polarization component (e.g., an LHCP component) of the second TIR propagating light 656 toward the coupling grating 645-2 with substantially zero diffraction or with negligible diffraction. The coupling grating 645-2 can be configured to couple a second polarization component (e.g., an LHCP component) of the second TIR propagating light 656 from the light guide 610 via diffraction as a second (or fourth) output light 666 (e.g., LHCP light). A first output light 665 (e.g., RHCP light) and a second output light 666 (e.g., LHCP light) with orthogonal polarization can form two images: one is the main image formed by the second output light 666 diffracted by the coupling grating 645-2, and the other is a mirrored virtual image formed by the first output light 665 diffracted by the coupling grating 645-1.

[0155] A second polarization switch 630 (e.g., SHWP) can be synchronized with a first polarization switch 623 (e.g., SHWP) to operate in a switching state. In the switching state, the second polarization switch 630 (e.g., SHWP) can be configured to switch or change the polarization of light to orthogonal polarization. For example, the second polarization switch 630 can switch the cycloidity of a first output light 665 (e.g., RHCP light) and output light 667 (e.g., LHCP light) with opposite polarization cycloidity. In some embodiments, the second polarization switch 630 (e.g., SHWP) can be configured to switch the cycloidity of a second output light 666 (e.g., LHCP light) and output light 668 (e.g., RHCP light) with opposite polarization cycloidity. Because polarizer 640 can be an absorptive circular polarizer configured to transmit RHCP light and block LHCP light via absorption, light 668 (e.g., RHCP light) can pass through polarizer 640 as a second output light 658 (e.g., RHCP light) propagating toward eye 260, while light 667 (e.g., LHCP light) can be blocked by polarizer 640 via absorption. Therefore, eye 260 will not receive light 667. Eye 260 can observe the main image formed by light 661 diffracted by coupling grating 645-2, and can ignore the illusory image formed by light 662 diffracted by coupling grating 645-1.

[0156] Reference Figure 6A and Figure 6BIn some embodiments, the first output light 657 may be defined by first output rays 657a and 657b. In some embodiments, the first coupling grating 645-1 may be configured to couple the first TIR propagation ray 655a from the light guide 610 as the first output ray 657a at a first output angle. In some embodiments, the first coupling grating 635-1 may be configured to couple the first ray 653b into the light guide 610, and the first coupling grating 645-1 may be configured to couple the first ray 653b from the light guide 610 as the first output ray 657b. In some embodiments, the first output light 657 may correspond to a first output FOV. The first output FOV may correspond to an angular region defined by the first output rays 657a and 657b. The second output light 658 may be defined by second output rays 658a and 658b. The second output grating 645-2 can be configured to couple the second TIR propagation ray 656a from the light guide 610 as a second output ray 658a at the second output angle. In some embodiments, the second input grating 635-1 can be configured to couple the second ray 654b into the light guide 610, and the second output grating 645-2 can be configured to couple the second ray 654b from the light guide 610 as a second output ray 658b. In some embodiments, the second output ray 658 can correspond to a second output FOV. The second output FOV can correspond to the angular region defined by the second output rays 658a and 658b. In some embodiments, the first output angle of the first output ray 657a and the second output angle of the second output ray 658a can have the same absolute value and opposite signs, such as opposite output angles +θ and -θ. In some embodiments, the first output angle of the first output ray 657a and the second output angle of the second output ray 658a may have different absolute values ​​and opposite signs (e.g., +θ1 and -θ2, where θ1 and θ2 have different values). In some embodiments, the first output ray 657b and the second output ray 658b may substantially overlap each other. Therefore, the FOV provided by the light guide display assembly 600 can be enlarged or expanded (e.g., doubled) compared to conventional light guide display assemblies (including stacked light guides made based on materials with the same or similar refractive index). Alternatively or additionally, the disclosed light guide display assembly 600 (having a light guide 610 made based on a material with a lower refractive index) can provide the same or similar FOV compared to conventional light guides.

[0157] The first input grating 635-1, light guide 610, and first output grating 645-1 can be configured to provide a first output FOV at the eye-friendly region of the light guide display assembly 600. The second input grating 635-2, light guide 610, and second output grating 645-2 can be configured to provide a second output FOV at the eye-friendly region of the light guide display assembly 600. The first output FOV and the second output FOV may be substantially non-overlapping. In some embodiments, the first output FOV and the second output FOV may be substantially non-overlapping consecutive FOVs (e.g., 0° to +50°, 0° to -50°). The combination of the first output FOV and the second output FOV may be substantially greater than each of the first output FOV and the second output FOV. In some embodiments, the combination of the first output FOV and the second output FOV at the output side of the light guide display assembly 600 may be greater than a predetermined FOV of the image light 650 emitted by the light source assembly 605 at the input side of the light guide display assembly 600. In some embodiments, the first TIR propagating light 655 may correspond to a first intermediate FOV, which is smaller than the first input FOV of the first light 653, and the second TIR propagating light 656 may correspond to a second intermediate FOV, which is smaller than the second input FOV of the second light 654. The combination of the first output FOV and the second output FOV at the output side of the light guide display component 600 may be greater than the combined FOV of the first intermediate FOV and the second intermediate FOV.

[0158] Figure 7A and Figure 7B A schematic diagram is shown of an optical device or optical system 700 configured to provide an extended field of view (FOV) according to another embodiment of the present disclosure. The optical system 700 may also be referred to as a light guide display assembly 700. Figure 7A and Figure 7B The light guide display component 700 shown may include, with Figure 2A The light guide display component 200 shown Figure 2B The light guide display component 250 shown Figure 3 The light guide display component 300 shown Figure 4 The light guide display component 400 shown Figure 5 The light guide display component 500 shown, or Figures 6A-6B The light guide display assembly 600 shown includes elements, structures, and / or functions that are identical or similar to those in the present invention. A description of identical or similar elements, structures, and / or functions can be found in conjunction with [the provided text]. Figure 2A , Figure 2B , Figure 3 , Figure 4 , Figure 5 , Figure 6A or Figure 6B The above description is presented.

[0159] like Figure 7A and Figure 7B As shown, the light guide display assembly 700 may include a light source assembly 705, a light guide stack 710, and a controller 715. The light source assembly 705 and the controller 715 can be... Figure 2A and Figure 2B The light source assembly 205 and controller 215 shown are shown. Figure 3 The light source assembly 305 and controller 315 shown are shown. Figure 4 The light source assembly 405 and controller 415 shown are shown. Figure 5 The light source assembly 505 and controller 515 shown, or Figure 6A and Figure 6B The illustrated embodiments of light source assembly 605 and controller 615 (or may be similar to light source assembly 205 and controller 215, light source assembly 305 and controller 315, light source assembly 405 and controller 415, light source assembly 505 and controller 515, or light source assembly 605 and controller 615). A description of light source assembly 705 and controller 715 can be referenced in conjunction with... Figure 2A , Figure 2B , Figure 3 , Figure 4 , Figure 5 , Figure 6A or Figure 6B The above description is presented.

[0160] The optical guide stack 710 may include multiple optical guides stacked together. For illustrative purposes, Figure 7A The light guide stack 710 is shown to include a first light guide 712 and a second light guide 714. Other suitable numbers of light guides can be used, such as three, four, five, etc. Each of the light guides 712 and 714 can be... Figures 2A-2B The light guide 210 shown Figure 3 The light guide 310 shown Figure 4 The light guide 410 shown Figure 5 The light guides 512 and 514 shown, or Figure 6A The embodiment of the light guide 610 shown (or may be similar to light guide 210, light guide 310, light guide 410, light guide 512 and 514, or light guide 610).

[0161] The light source assembly 705 may include a light source (e.g., an electronic display) 720 and a light adjustment system 725, the light adjustment system including a polarization conversion element 722, a collimator 721, and a first polarization switch 723. The light source and the light adjustment system can be coupled with... Figure 6A and Figure 6BThe light source 620 and light adjustment system 625 (including polarization conversion element 622, collimator 621, and first polarization switch 623) shown are similar. In some embodiments, the light source 720, polarization conversion element 722, and collimator 721 may also be... Figure 5 The light source 520, polarization conversion element 522, and collimator 521 shown are similar. In some embodiments, the light source 720, polarization conversion element 722, and collimator 721 may also be similar to... Figure 4 The light source 420, polarization conversion element 422, and collimator 421 shown are similar. In some embodiments, the light source 720, polarization conversion element 722, and collimator 721 may also be similar to... Figure 3 The light source 320, polarization conversion element 322, and collimator 321 shown are similar. In some embodiments, the light source 720 and light adjustment system 725 can also be integrated with... Figure 2A and Figure 2B The light source 220 and light adjustment system 225 shown are similar. Descriptions of the same or similar components, structures, and / or functions can be found in conjunction with [other descriptions]. Figure 2A , Figure 2B , Figure 3 , Figure 4 , Figure 5 , Figure 6A or Figure 6B The above description is presented.

[0162] Light with a predetermined field of view (FOV) (e.g., equal to or less than 60°) can be configured to have two orthogonally polarized portions (e.g., a first light and a second light with orthogonal polarization). Each of these two orthogonally polarized portions can be associated with the full predetermined FOV. The light source assembly 705 can be configured to output the first and second light with orthogonal polarization in a time-sequential manner (e.g., during two consecutive subframes of a display frame), which can be achieved by a first polarization switch 723 coupled to the light source 720. The light guide stack 710 can be configured to receive the first light as a first input light and the second light as a second input light during the two consecutive subframes, respectively.

[0163] The light guide stack 710 may include one or more coupling elements coupled to each light guide 712 or 714. In some embodiments, each coupling element may be polarization selective. In some embodiments, each coupling element includes one or more gratings. For the purposes of discussion, each coupling element may be referred to as a coupling grating. It should be understood that in other embodiments, non-grating structures may be used as coupling elements. Figure 7AIn the illustrated embodiment, light guides 712 and 714 can be coupled to a first coupling grating 735-1 and a second coupling grating 735-2, respectively. The first coupling grating 735-1 and the second coupling grating 735-2 can be configured to couple a first input light and a second input light to light guides 712 and 714, respectively, via diffraction during two consecutive subframes. The first and second input lights can propagate within their respective light guides 712 and 714 via TIR at substantially the same propagation angle. The polarization of the first input light and the polarization of the second input light can be maintained within the respective light guides 712 and 714, for example, by means of... Figure 3 One or more polarization correction films, similar to the polarization correction film 330 shown, are used to maintain the polarization of the first input light and the polarization of the second input light.

[0164] The light guide stack 710 also includes one or more coupling elements coupled to each of the light guides 712 and 714. In some embodiments, each coupling element may be polarization selective. In some embodiments, each of these coupling elements may include one or more gratings. For the purposes of discussion, each coupling element may be referred to as a coupling grating. It should be understood that in other embodiments, non-grating structures may be used as coupling elements. Figure 7A In the illustrated embodiment, light guides 712 and 714 can be coupled to a first coupling grating 745-1 and a second coupling grating 745-2, respectively. The first coupling grating 745-1 and the second coupling grating 745-2 can be configured to couple first and second light propagating within light guides 712 and 714 via diffraction during two consecutive subframes, with the latter emerging in different directions (or at multiple diffraction angles). Each of the coupling gratings 735-1 and 735-2 and the coupling gratings 745-1 and 745-2 can be a transmissive grating (e.g., a transmissive PVH) or a reflective grating (e.g., a reflective PVH).

[0165] Reference Figure 7A and Figure 7BIn some embodiments, the light source 720 can generate an image light 750 (representing a virtual image or a display image) with a predetermined FOV (e.g., equal to or less than 60°), which corresponds to the display image with a predetermined FOV (e.g., equal to or less than 60°). The image light 750 can be unpolarized or polarized. In some embodiments, the image light 750 can be divergent light. The image light 750 can be configured with two portions (e.g., two lights) 751 and 752, each corresponding to the full predetermined FOV of the image light 750. The light source 720 can be configured to emit the two lights 751 and 752 in a time-sequential manner. For example, a display frame of the display image generated by the light source 720 can include two consecutive subframes, namely a first subframe and a second subframe. The light source 720 can be configured to emit light 751 (e.g., 751) corresponding to the full predetermined FOV of the image light 750 during the first subframe. Figure 7A (as shown), and during the second subframe, emit light 752 corresponding to the fully predetermined FOV of image light 750 (as shown). Figure 7B (As shown).

[0166] The light conditioning system 725 can be configured to receive light 751 from the light source 720 during the first subframe and process the light 751 to output first light 753 (e.g., ...). Figure 7A (As shown). The light conditioning system 725 can be configured to receive light 752 from the light source 720 during the second subframe and process the light 752 to output a second light 754 (as shown). Figure 7B (As shown). The first light 753 and the second light 754 may have orthogonal polarization. The first light 753 and the second light 754 may have a first input FOV and a second input FOV. In some embodiments, each of the first light 753 and the second light 754 may be associated with the full FOV of the image light 750 generated by the light source 720. That is, the first input FOV and the second input FOV may each be the full FOV of the image light 750. Figure 7A As shown, the optical guide stack 710 can be configured to receive a first light 753 during a first subframe as a first input light. Figure 7B As shown, the optical guide stack 710 can be configured to receive a second light 754 during a second subframe as a second input light. Figure 7A and Figure 7BIn the yz cross-sectional view shown, a first input light 753 with a full predetermined FOV can be defined by first rays 753a and 753b. For example, first ray 753a can be the rightmost ray of the first input light 753, and first ray 753b can be the leftmost ray of the first input light 753. A second input light 754 with a full predetermined FOV can be defined by second rays 754a and 754b. For example, second ray 754a can be the leftmost ray of the second input light 754, and second ray 754b can be the rightmost ray of the second input light 754. In some embodiments, second ray 754b (e.g., the rightmost ray of the second input light 754) and first ray 753b (e.g., the leftmost ray of the first input light 753) can substantially overlap each other.

[0167] In some embodiments, the first polarization switch 723 may be an active element configured to maintain the polarization of incident light or switch the polarization of incident light to orthogonal polarization depending on the operating state of the first polarization switch 723 (e.g., switched or unswitched state). For example, the first polarization switch 723 may be configured to maintain the cycloidium of circularly polarized incident light or switch the cycloidium of circularly polarized incident light to the opposite cycloidium depending on the operating state of the first polarization switch 723 (e.g., switched or unswitched state). In some embodiments, a polarization conversion element 722 may be disposed between the light source 720 and the first polarization switch 723, and the polarization conversion element is configured to polarize the light emitted by the light source 720 before the light is incident on the first polarization switch 723. In some embodiments, the polarization conversion element 722 may be disposed between the first polarization switch 723 and the collimator 721, and the polarization conversion element is configured to polarize the light output from the first polarization switch 723 to a predetermined polarization (e.g., circular polarization). In some embodiments, collimator 721 (e.g., collimating lens) may be configured to collimate the light generated by light source 720. For example, collimator 721 may collimate the light output from first polarization switch 723. In some embodiments, polarization conversion element 722 may be omitted. In some embodiments, first polarization switch 723 may not be part of light source assembly 705, but may be disposed between light source assembly 705 and light guide stack 710. In some embodiments, first polarization switch 723 may not be part of light source assembly 705, but may be part of light guide stack 710. For example, first polarization switch 723 may be disposed on the surface of one of light guides 712 and 714 in light guide stack 710.

[0168] In some embodiments, the first polarization switch 723 may include a circularly polarized light switch (SHWP). For example, the light source 720 may be configured to emit circularly polarized light with a first directionality toward the first polarization switch 723 (e.g., SHWP). In some embodiments, the polarization conversion element 722 may be omitted. The controller 715 may control the first polarization switch 723 (e.g., SHWP) to operate in a non-switching state to maintain the directionality of the circularly polarized light. The controller 715 may also control the first polarization switch 723 (e.g., SHWP) to operate in a switching state to switch the directionality of the circularly polarized light from the first directionality to a second directionality opposite to the first directionality.

[0169] In some embodiments, the light source 720 may be configured to emit linearly polarized light, and the polarization conversion element 722 may include a QWP configured to convert linearly polarized light into circularly polarized light having a first directionality. The QWP may output circularly polarized light having the first directionality to a first polarization switch 723 (e.g., SHWP). In some embodiments, the light source 720 may be configured to emit unpolarized light, and the polarization conversion element 722 may include a linear polarizer and a QWP. The linear polarizer may be configured to convert unpolarized light into linearly polarized light. The QWP may be configured to convert linearly polarized light into circularly polarized light having a first directionality. The QWP may output circularly polarized light having the first directionality to a first polarization switch 723 (e.g., SHWP). In some embodiments, when the light source 720 emits unpolarized light, a circular polarizer may be used instead of the combination of a linear polarizer and a QWP.

[0170] In some embodiments, the light guide 712 can be coupled to the first coupling grating 735-1 and the first coupling grating 745-1. The light guide 714 can be coupled to the second coupling grating 735-2 and the second coupling grating 745-2. The coupling gratings 735-1 and 735-2 can be... Figure 3 The coupling gratings 335-1 and 335-2 shown are... Figure 4 The coupling gratings 435-1 and 435-2 shown are... Figure 5 The coupling gratings 535-1 and 535-2 shown, or Figure 6A The embodiments of coupling gratings 635-1 and 635-2 shown (or may be similar to coupling gratings 335-1 and 335-2, coupling gratings 435-1 and 435-2, coupling gratings 535-1 and 535-2, or coupling gratings 635-1 and 635-2). The output gratings 745-1 and 745-2 may be... Figure 3 The coupling gratings 345-1 and 345-2 shown are... Figure 4 The coupling gratings 445-1 and 445-2 shown are... Figure 5 The coupling gratings 545-1 and 545-2 shown, or Figure 6AThe embodiments of the coupling gratings 645-1 and 645-2 shown are (or may be similar to coupling gratings 345-1 and 345-2, coupling gratings 445-1 and 445-2, coupling gratings 545-1 and 545-2, or coupling gratings 645-1 and 645-2). In some embodiments, coupling gratings 735-1 and 735-2 may be reflective PVH gratings configured to back-diffuse circularly polarized light with opposite rotation, and coupling gratings 745-1 and 745-2 may be reflective PVH gratings configured to back-diffuse circularly polarized light with opposite rotation. Each coupling grating in coupling gratings 745-1 and 745-2 may have the same polarization selectivity as one of the coupling gratings in coupling gratings 735-1 and 735-2. For example, in some embodiments, the output grating 745-1 may have the same polarization selectivity as the input grating 735-1, and the output grating 745-2 may have the same polarization selectivity as the input grating 735-2. In some embodiments, for waveguide phenomena occurring in the optical guide, optical guides 712 and 714 may be separated by an air gap. In some embodiments, the air gap between optical guides 712 and 714 may be at least partially filled with a material (e.g., an adhesive) with a refractive index lower than that of the optical guide.

[0171] Reference Figure 7A During the first subframe of the display frame, the light source 720 can emit light 751 toward the polarization conversion element 722. For illustrative purposes, light 751 can be unpolarized light or linearly polarized light. The polarization conversion element 722 can be configured to polarize light 751 into circularly polarized light (e.g., RHCP light). The polarization conversion element 722 can output circularly polarized light to a first polarization switch 723 (e.g., SHWP). The controller 715 can control the first polarization switch 723 (e.g., SHWP) to operate in a non-switching state to transmit circularly polarized light (e.g., RHCP light) without affecting polarization. For example, the first polarization switch 723 (e.g., SHWP) can transmit circularly polarized light (e.g., RHCP light) received from the polarization conversion element 722 as circularly polarized light (e.g., RHCP light). The coupling grating 735-1 can be configured to couple the first input light 753 (e.g., RHCP light) into the light guide 712 via diffraction as a first TIR propagation light 755 (e.g., RHCP light). For illustrative purposes, Figure 7A A first TIR propagation ray 755a is shown. A first coupling grating 735-1 can couple the first ray 453a into the light guide 712 as the first TIR propagation ray 755a. The corresponding TIR propagation ray of the first ray 753b is not shown. Figure 7AThe initial polarization (e.g., right-handed circular polarization) of the first TIR propagating light 755 can be maintained as the first TIR propagating light propagates through the TIR within the optical guide 712 toward the coupling grating 745-1, for example, by means of... Figure 3 One or more polarization correction films, similar to the polarization correction film 330 shown, are used to maintain this.

[0172] The coupling grating 745-1 can be configured to couple a first TIR propagating light 755 (e.g., RHCP light) from the light guide 712 via diffraction as a first output light 757 (e.g., RHCP light). Since the coupling grating 745-2 is configured to back-diffract the LHCP light and transmit the RHCP light, the first output light 757 (e.g., RHCP light) can be transmitted toward the eye 260 via the coupling grating 745-2 and the light guide 714 with substantially zero diffraction or with negligible diffraction. Figure 7A In the illustrated embodiment, the first output light 757 can be defined by first output light rays 757a and 757b. In some embodiments, the first output light 757 can correspond to a first output FOV. In some embodiments, the first output FOV can be greater than the full predetermined FOV of the first input light 753.

[0173] Reference Figure 7B During the second subframe of the display frame, the light source 720 may output light 752 toward the polarization conversion element 722. For illustrative purposes, light 752 may be unpolarized or linearly polarized light. The polarization conversion element 722 may be configured to polarize light 752 into circularly polarized light (e.g., RHCP light) and may output circularly polarized light toward a polarization switch 723 (e.g., SHWP). The polarization switch 723 (e.g., SHWP) may be configured to operate in a switching state to switch the directionality of the circularly polarized light (e.g., RHCP light) to the opposite directionality. For example, the polarization switch 723 (e.g., SHWP) may transmit circularly polarized light (e.g., RHCP light) received from the polarization conversion element 722 as circularly polarized light with the opposite directionality (e.g., LHCP light).

[0174] Since the coupling grating 735-1 can be configured to back-diffuse RHCP light and transmit LHCP light, the second input light 754 (e.g., LHCP light) can be transmitted through the light guide 712 and the coupling grating 735-1 toward the coupling grating 735-2 without diffraction and without changing its polarization. The coupling grating 735-2 can be configured to couple the second input light 754 (e.g., LHCP light) to the light guide 714 via diffraction as a second TIR propagation light 756 (e.g., LHCP light). For illustrative purposes, Figure 7BA second TIR propagation ray 756a is shown. A second coupling grating 735-2 can couple the second ray 754a into the light guide 714 as the second TIR propagation ray 756a. The corresponding TIR propagation ray 754b is not shown. Figure 7B As shown in the diagram, the initial polarization (e.g., left-handed circular polarization) of the second TIR propagating light 756 can be maintained as the second TIR propagating light propagates through the TIR within the optical guide 714 toward the coupling grating 745-2, for example, by means of... Figure 3 One or more polarization correction films, similar to the polarization correction film 330 shown, are used to maintain this. The coupling grating 745-2 can be configured to couple a second TIR propagating light 756 (e.g., LHCP light) from the light guide 714 via diffraction as a second output light 758 (e.g., LHCP light) propagating toward the eye 260. Figure 7B In the illustrated embodiment, the second output light 758 can be defined by second output rays 758a and 758b. In some embodiments, the second output light 758 can correspond to a second output FOV. In some embodiments, the second output FOV can be greater than the full predetermined FOV of the second input light 754.

[0175] Reference Figure 7A and Figure 7BIn some embodiments, the first coupling grating 745-1 may be configured to couple a first TIR propagation ray 755a from the light guide 712 as a first output ray 757a at a first output angle. In some embodiments, the first coupling grating 735-1 may be configured to couple a first ray 753b into the light guide 712, and the first coupling grating 745-1 may be configured to couple the first ray 753b from the light guide 712 as a first output ray 757b. The first output FOV may correspond to the angular region defined by the first output rays 757a and 757b. In some embodiments, the second coupling grating 745-2 may be configured to couple a second TIR propagation ray 756a from the light guide 714 as a second output ray 758a at a second output angle. In some embodiments, a second coupling grating 735-1 may be configured to couple a second ray 754b into a light guide 712, and a second coupling grating 745-2 may be configured to couple the second ray 754b out of the light guide 714 as a second output ray 758b. In some embodiments, a first output angle of a first output ray 757a and a second output angle of a second output ray 758a may have the same absolute value and opposite signs, such as opposite output angles +θ and -θ. In some embodiments, a first output angle of a first output ray 757a and a second output angle of a second output ray 758a may have different absolute values ​​and opposite signs (e.g., +θ1 and -θ2, where θ1 and θ2 have different values). In some embodiments, the first output ray 757b and the second output ray 758b may substantially overlap each other. Therefore, when the light guides included in the light guide display assembly 700 and conventional light guide display assemblies are manufactured based on materials with the same or similar refractive indices, the FOV provided by the light guide display assembly 700 may be enlarged or extended (e.g., doubled) compared to a conventional light guide display assembly. Alternatively or additionally, the disclosed light guide display assembly 700 (with light guides 712 and 714 made of materials with lower refractive index) can provide the same or similar FOV compared to conventional light guide display assemblies.

[0176] exist Figure 7A and Figure 7BIn the illustrated embodiment, the first coupling grating 735-1, light guide 712, and first output grating 745-1 can be configured to provide a first output FOV at the eye-friendly region of the light guide display assembly 700. The second coupling grating 735-2, light guide 714, and second output grating 745-2 can be configured to provide a second output FOV at the eye-friendly region of the light guide display assembly 700. The first output FOV and the second output FOV may be substantially non-overlapping. In some embodiments, the first output FOV and the second output FOV may be substantially non-overlapping consecutive FOVs (e.g., 0° to +50°, 0° to -50°). The combination of the first output FOV and the second output FOV may be substantially greater than each of the first output FOV and the second output FOV. In some embodiments, the combination of the first output FOV and the second output FOV at the output side of the light guide display assembly 700 may be greater than a predetermined FOV of the image light 750 emitted by the light source 720 at the input side of the light guide display assembly 700. In some embodiments, the first TIR propagation light 755 may correspond to a first intermediate FOV, which is smaller than the first input FOV of the first input light 753, and the second TIR propagation light 756 may correspond to a second intermediate FOV, which is smaller than the second input FOV of the second input light 354. The combination of the first output FOV and the second output FOV at the output side of the light guide display component 700 may be greater than the combination of the first intermediate FOV and the second intermediate FOV.

[0177] In some embodiments, such as Figure 7A As shown, the second polarization switch 730 can be disposed between the light guide stack 710 (e.g., light guide 714) and the eye 260. The second polarization switch 730 can be an embodiment of the first polarization switch 723 (or can be similar to the first polarization switch 723). In some embodiments, the second polarization switch 730 can be synchronized with the first polarization switch 723. In some embodiments, the controller 715 can control the second polarization switch 730 and the first polarization switch 723 to operate in a synchronized state, i.e., both operate in a switched state or a non-switched state during the same subframe (e.g., one of the first and second subframes). In some embodiments, the second polarization switch 730 may not be synchronized with the first polarization switch 723. For example, the controller 715 can control the second polarization switch 730 and the first polarization switch 723 to operate in different operating states during the same subframe. For example, the controller 715 can control the second polarization switch 730 and the first polarization switch 723 to operate in a switched state during different subframes and in a non-switched state during different subframes.

[0178] By controlling the second polarization switch 730 to operate in a switched state during one of the first and second subframes and in a non-switched state during the other subframe, the eye 260 can receive two output lights with the same polarization. For example, during the first subframe, the controller 715 can control the second polarization switch 730 to operate in the non-switched state, thereby maintaining the polarization of light 757 (e.g., RHCP light) and transmitting light 757 as light 757' (e.g., RHCP light) without changing polarization to the eye 260. During the second subframe, the controller 715 can control the second polarization switch 730 to operate in a switched state, thereby switching the polarization of light 758 (e.g., LHCP light) to the opposite polarization and transmitting light 758 as light 758' (e.g., RHCP light) with changed polarization to the eye 260. Therefore, the eye 260 can receive two output lights 757' and 758' with the same polarization in different subframes. In addition to controlling the first polarization switch 723 and the second polarization switch 730, the controller 715 can control various other components (such as the light source assembly 705) included in the light guide display assembly 700.

[0179] For the purpose of explanation, Figures 2A to 7B The light source assembly and eye are shown located on opposite sides of the light guide or light guide stack. Although not shown, in some embodiments, the light source assembly and eye may be located on the same side of the light guide or light guide stack. The light guide or light guide stack shown or described in various embodiments, and the features of the light guide or light guide stack, can be combined. In some embodiments, all coupling-in gratings and coupling-out gratings may be the same type of polarization-selective grating, such as a transmissive PVH grating or a reflective PVH grating. In some embodiments, the coupling-in gratings and coupling-out gratings may include different types of polarization-selective gratings, for example, at least one of the coupling-in gratings or coupling-out gratings may be a different grating type than the others. For example, in Figure 3 In the illustrated embodiment, at least one of the coupling gratings (335-1 and 335-2) and the coupling gratings (345-1 and 345-2) can be a transmissive PVH grating, while the remaining gratings can be reflective PVH gratings. Figure 4 In the illustrated embodiment, at least one of the coupling gratings (435-1 and 435-2) and the coupling out gratings (445-1 and 445-2) can be a reflective PVH grating, while the remaining gratings can be transmissive PVH gratings. Figure 5 In the illustrated embodiment, at least one of the coupling gratings (535-1 and 535-2) and the coupling out gratings (545-1 and 545-2) can be a transmissive PVH grating, while the remaining gratings can be reflective PVH gratings. Figure 6A and Figure 6BIn the illustrated embodiment, at least one of the coupling gratings (635-1 and 635-2) and the coupling out gratings (645-1 and 645-2) can be a transmissive PVH grating, while the remaining gratings can be reflective PVH gratings. Figure 7A and Figure 7B In the illustrated embodiment, at least one of the coupling gratings (735-1 and 735-2) and the coupling gratings (745-1 and 745-2) may be a transmissive PVH grating, while the other gratings may be a reflective PVH grating.

[0180] In some embodiments, a set of coupling-in gratings and a set of coupling-out gratings may be arranged in the same manner (e.g., side-by-side or stacked at the light guide) or in different manner. A set of coupling-in gratings may be located on the same side as the coupling-out gratings, or on a different side than the side where the other set of coupling-out gratings is located. For example, in Figure 3 In the illustrated embodiment, one set of coupling gratings (335-1 and 335-2) and one set of output gratings (345-1 and 345-2) can be arranged side-by-side at the light guide 310, while the other set can be stacked at the light guide 310. Figure 4 In the illustrated embodiment, one set of coupling gratings (435-1 and 435-2) and one set of output gratings (445-1 and 445-2) can be arranged side-by-side at the light guide 410, while the other set can be stacked at the light guide 410. Figure 6A and Figure 6B In the illustrated embodiment, one set of a set of coupling-in gratings (635-1 and 635-2) and a set of coupling-out gratings (645-1 and 645-2) can be arranged side by side at the light guide 610, while the other set can be stacked at the light guide 610.

[0181] In some embodiments, similar to Figure 5 The image shown is a light guide display assembly 500 with two light guides for transmitting two different parts of the field of view (FOV). Figure 4 The illustrated light guide display assembly 400 may include two light guides for transmitting two different portions of the field of view (FOV). In some embodiments, Figure 6A and Figure 6B The illustrated light guide display assembly 600 may include two light guides for transmitting two different portions of the field of view (FOV). In some embodiments, Figure 7A and Figure 7B The light guide display assembly 700 shown may include a light guide for transmitting two types of light, each corresponding to the full field of view in a timing manner.

[0182] All embodiments shown in the accompanying drawings illustrate a light guide display assembly configured to provide 1D FOV expansion, serving as examples for describing the principles of FOV expansion. To achieve 2D FOV expansion, the light guide display assembly may include additional gratings. In addition to the direction of FOV expansion, in the x-axis direction (perpendicular to the illustrated expansion direction (y-axis direction), the additional gratings may perform various functions similar to the illustrated gratings.

[0183] For example, in Figure 3 In the illustrated light guide display assembly, to provide 2D FOV expansion, two additional coupling gratings can be stacked with coupling gratings 345-1 and 345-2 on the first surface 310-1. In some embodiments, the two additional coupling gratings can be stacked together and arranged side-by-side with coupling gratings 345-1 and 345-2 on the first surface 310-1. In some embodiments, the two additional coupling gratings can be stacked together and (opposite to the stack of the two coupling gratings 345-1 and 345-2) arranged on the second surface 310-2.

[0184] exist Figure 4 In the illustrated light guide display assembly, to provide 2D FOV expansion, two additional coupling gratings can be stacked with two coupling gratings 445-1 and 445-2. In some embodiments, the two additional coupling gratings can be stacked together and disposed (opposite to the stacked coupling gratings 445-1 and 445-2) on the first surface 410-1. In some embodiments, the two additional coupling gratings can be stacked together and disposed side-by-side with the stack of coupling gratings 445-1 and 445-2. In some embodiments, the two additional coupling gratings can be disposed side-by-side on the first surface 410-1. In some embodiments, the two additional coupling gratings can be disposed side-by-side on the second surface 410-2 with the stack of coupling gratings 445-1 and 445-4.

[0185] exist Figure 5In the illustrated light guide display assembly, additional coupling gratings may be included to provide 2D FOV expansion. In various configurations, the additional coupling gratings may be combined with existing coupling gratings. Exemplary configurations are shown below. Other variations of these configurations may also be used. In some embodiments, the additional coupling grating may be stacked with coupling grating 545-1, and the additional coupling grating may be stacked with coupling grating 545-2. In some embodiments, the additional coupling grating may be disposed opposite to coupling grating 545-1 on the second surface 512-2, and the additional coupling grating may be disposed opposite to coupling grating 545-2 on the second surface 514-2. In some embodiments, the additional coupling grating may be disposed side-by-side with coupling grating 545-1, and the additional coupling grating may be disposed side-by-side with the second surface 514-2.

[0186] exist Figure 6A and Figure 6B In the light guide display assembly shown, additional coupling gratings may be included to provide 2D FOV expansion. These additional coupling gratings can be configured in various ways in conjunction with the above. Figure 3 The 2D FOV extension of the light guide display assembly shown describes similar constructions to those used in combination with existing coupling gratings. In some embodiments, additional polarization conversion elements may be included.

[0187] exist Figure 7A and Figure 7B In the light guide display assembly shown, additional coupling gratings may be included to provide 2D FOV expansion. These additional coupling gratings can be configured in various ways in conjunction with the above. Figure 5 The 2D FOV extension of the light guide display assembly shown describes similar constructions to those used in combination with existing coupling gratings. In some embodiments, additional polarization conversion elements may be included.

[0188] Figure 8A flowchart illustrating a method 800 for providing an extended field of view (FOV) according to embodiments of the present disclosure is provided. Method 800 may include: coupling a first light having a first polarization and a first input FOV into one or more light guides as a first total internal reflection (“TIR”) propagating light (step 810). For example, a first coupling element may couple the first light into one or more light guides as a first TIR propagating light. Method 800 may further include: coupling a second light having a second polarization and a second input FOV into one or more light guides as a second TIR propagating light (step 820). For example, a second coupling element may couple the second light into one or more light guides as a second TIR propagating light. The first polarization and the second polarization may be orthogonal polarizations. In some embodiments, the one or more light guides may include a single light guide coupled to a first coupling element (e.g., a first coupling grating), a second coupling element (e.g., a second coupling grating), and one or more coupling elements (e.g., coupling out gratings). The coupling grating may be configured to couple the first light and the second light into the light guide via diffraction. In some embodiments, one or more light guides may include two or more light guides (forming a light guide stack), each light guide being coupled to one or more input gratings and one or more output gratings. A first light beam may be coupled into the first light guide via one or more input gratings coupled to the first light guide. A second light beam may be coupled into the second light guide via one or more input gratings coupled to the second light guide. The first and second light beams may be coupled into the one or more light guides during the same subframe (e.g., simultaneously) or during different subframes (e.g., sequentially).

[0189] Method 800 may further include decoupling a first TIR propagating light from one or more light guides as a first output light corresponding to a first output FOV (step 830). For example, a first coupling element may decouple the first TIR propagating light from one or more light guides as a first output light corresponding to a first output FOV. Method 800 may further include decoupling a second TIR propagating light from one or more light guides as a second output light corresponding to a second output FOV (step 840). For example, one or more coupling gratings coupled to one or more light guides may decouple the first TIR propagating light and the second TIR propagating light from one or more light guides via diffraction as a first output light corresponding to a first output FOV and a second output light corresponding to a second output FOV. The coupling elements and coupling elements may be polarization-selective. For example, the coupling elements and coupling elements may include reflective PVH gratings or transmissive PVH gratings. Thus, light with different polarizations (e.g., orthogonal polarizations) can be coupled into the light guide through different coupling gratings and decoupled from the light guide in different directions through different coupling gratings. The first output FOV and the second output FOV may be substantially non-overlapping. In some embodiments, the first output FOV and the second output FOV may be substantially non-overlapping consecutive FOVs (e.g., 0° to +50°, 0° to -50°). The combination of the first output FOV and the second output FOV may be substantially greater than each of the first output FOV and the second output FOV. In some embodiments, the combination of the first output FOV of the first output light and the second output FOV of the second output light may be substantially greater than the first input FOV of the first light and the second input FOV of the second light coupled to one or more light guides.

[0190] Method 800 may include other additional steps or processes. For example, in some embodiments, method 800 may include generating a first light with a first polarization. For example, the disclosed light source assembly may generate the first light with the first polarization and may output the first light toward a first coupling element that may couple the first light into one or more light guides. Method 800 may also include generating a second light with a second polarization. For example, the disclosed light source assembly may generate the second light with the second polarization and may output the second light to a second coupling element that may couple the second light into one or more light guides. The second polarization may be orthogonal to the first polarization. In some embodiments, each of the first light and the second light may correspond to a different portion of a predetermined field of view (FOV) of image light generated by the light source assembly. In some embodiments, each of the first light and the second light may correspond substantially to the entire (e.g., full) predetermined FOV. In some embodiments, method 800 may include controlling the light source assembly via a controller to generate the first light and the second light. In some embodiments, method 800 may include controlling the light source assembly via a controller to generate the first light and the second light during the same subframe (e.g., simultaneously). In some embodiments, method 800 may include controlling a light source assembly via a controller to generate a first light and a second light in a temporally sequential manner over two consecutive subframes of a display frame. In some embodiments, when the first light and the second light are generated during the same subframe, the first light and the second light may be coupled into one or more light guides during the same subframe, and the first TIR propagation light and the second TIR propagation light may be coupled out from one or more light guides during the same subframe. In some embodiments, when the first light and the second light are generated over two consecutive subframes (e.g., a first subframe and a second subframe), the first light may be coupled into one or more light guides during the first subframe, and the first TIR propagation light may be coupled out from one or more light guides during the first subframe. The second light may be coupled into one or more light guides during the second subframe, and the second TIR propagation light may be coupled out from one or more light guides during the second subframe.

[0191] Some portions of this specification describe embodiments of the present disclosure based on algorithms and symbolic representations of information operations. While these operations are described functionally, computationally, or logically, they can be implemented by computer programs or equivalent electronic circuits or microcode, etc. Furthermore, it has proven convenient in some cases to refer to arrangements of these operations as modules, without loss of generality. The described operations and their associated modules can be embodied in software, firmware, hardware, or any combination thereof.

[0192] Any step, operation, or process described herein may be performed or implemented using one or more hardware and / or software modules, individually or in combination with other devices. In one embodiment, a software module is implemented using a computer program product comprising a computer-readable medium containing computer program code that can be executed by a computer processor to perform any or all of the described steps, operations, or processes. In some embodiments, a hardware module may include hardware components such as devices, systems, optical elements, controllers, electronic circuits, logic gates, etc.

[0193] Embodiments of this disclosure may also relate to means for performing the operations described herein. Such means may be specifically constructed for a particular purpose, and / or 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-transitory tangible computer-readable storage medium, or any type of medium suitable for storing electronic instructions that may be coupled to a computer system bus. A non-transitory computer-readable storage medium may be any medium capable of storing program code, such as a disk, optical disk, read-only memory (“ROM”), random access memory (“RAM”), electrically programmable read-only memory (“EPROM”), electrically erasable programmable read-only memory (“EEPROM”), registers, hard disk, solid-state drive, smart media card (“SMC”), secure digital card (“SD”), flash memory card, etc. Furthermore, any computing system described in the specification may include a single processor, or may be an architecture employing multiple processors to enhance computing power. A processor can be a central processing unit (“CPU”), a graphics processing unit (“GPU”), or any processing device configured to process data and / or perform computations based on data. A processor can include software and hardware components. For example, a processor can include hardware components such as application-specific integrated circuits (“ASICs”), programmable logic devices (“PLDs”), or any combination thereof. A PLD can be a complex programmable logic device (“CPLD”), a field-programmable gate array (“FPGA”), etc.

[0194] Embodiments of this disclosure may also relate to products generated by the computational processes described herein. Such products may include information generated by the computational processes, wherein the information is stored on a non-transitory tangible computer-readable storage medium, and may include any embodiment of a computer program product or other combination of data described herein.

[0195] Furthermore, when the embodiments shown in the accompanying drawings depict a single element, it should be understood that embodiments or other embodiments not shown in the drawings but within the scope of this disclosure may include multiple such elements. Similarly, when the embodiments shown in the accompanying drawings depict multiple such elements, it should be understood that embodiments or other embodiments not shown in the accompanying drawings but within the scope of this disclosure may include only one such element. The number of elements shown in the accompanying drawings is for illustrative purposes only and should not be construed as limiting the scope of the embodiments. Furthermore, unless otherwise stated, the embodiments shown in the accompanying drawings are not mutually exclusive, and they may be combined in any suitable manner. For example, an element shown in one accompanying drawing / embodiment but not in another accompanying drawing / embodiment may still be included in another accompanying drawing / embodiment. In any optical device disclosed herein that includes one or more optical layers, films, plates, or elements, the number of layers, films, plates, or elements shown in the accompanying drawings is for illustrative purposes only. In other embodiments not shown in the accompanying drawings that are still within the scope of this disclosure, the same or different layers, films, plates, or elements shown in the same or different accompanying drawings / embodiments may be combined or repeated in various ways to form a stack.

[0196] Various embodiments have been described to illustrate exemplary implementations. Based on the disclosed embodiments, those skilled in the art can make various other changes, modifications, rearrangements, and substitutions without departing from the scope of this disclosure. Therefore, although this disclosure has been described in detail with reference to the above embodiments, this disclosure is not limited to the above embodiments. This disclosure may be embodied in other equivalent forms without departing from the scope of this disclosure.

Claims

1. An optical device comprising: one or more light guides; a first in-coupling element configured to couple first light having a first input field of view (FOV) into a first light guide; a second in-coupling element configured to couple second light having a second input FOV into a second light guide; a first out-coupling element configured to couple the first light out of the first light guide as first output light having a first output FOV; and a second out-coupling element configured to couple the second light out of the second light guide as second output light having a second output FOV that is substantially non-overlapping with the first output FOV, wherein a combination of the first output FOV and the second output FOV is greater than at least one of the first output FOV or the second output FOV; wherein at least one of the first in-coupling element, the second in-coupling element, the first out-coupling element, or the second out-coupling element comprises a polarization selective element.

2. The optical device of claim 1, wherein: the combination of the first output FOV and the second output FOV is greater than each of the first output FOV and the second output FOV.

3. The optical device of claim 1, wherein: the first out-coupling element is configured to couple the first light out of the first light guide at different locations of the first out-coupling element, and the second out-coupling element is configured to couple the second light out of the second light guide at different locations of the second out-coupling element.

4. The optical device of claim 1, wherein: the first in-coupling element is configured to substantially couple the first light having a first polarization into the first light guide as first totally internally reflected propagating light and substantially transmit the second light having a second polarization that is orthogonal to the first polarization; and the second in-coupling element is configured to substantially couple the second light having the second polarization into the second light guide as second totally internally reflected propagating light and substantially transmit the first light having the first polarization.

5. The optical device of claim 4, wherein: the first out-coupling element is configured to substantially couple the first totally internally reflected propagating light having a third polarization out of the first light guide and substantially transmit the second totally internally reflected propagating light having a fourth polarization that is orthogonal to the third polarization; and the second out-coupling element is configured to substantially couple the second totally internally reflected propagating light having the fourth polarization out of the second light guide and substantially transmit the first totally internally reflected propagating light having the third polarization. the polarization selective element comprises a polarization selective grating or a holographic element comprising at least one of a sub-wavelength structure, a liquid crystal, or a photorefractive holographic material.

6. The optical device of claim 1, wherein, ​ 7. The optical device of claim 6, wherein, The polarization selective element includes a liquid crystal polymer material having an optical axis with an orientation that spatially varies in an in-plane direction and in an out-of-plane direction.

8. The optical device of claim 1, further comprising: one or more polarization correction films disposed at a surface of at least one of the first light guide or the second light guide, and configured to maintain a polarization of at least one of the first light or the second light as the first light and the second light propagate inside the first light guide and the second light guide by total internal reflection.

9. The optical device of claim 1, wherein: the first out-coupling element is configured to couple out a first polarization component of the first light from the first light guide during a first sub-frame of a display frame as the first output light, the second out-coupling element is configured to couple out a second polarization component of the first light from the second light guide during the first sub-frame as the second output light, the optical device further comprises a polarization switch configured to maintain a polarization of the first output light and a polarization of the second output light during the first sub-frame, and the optical device further comprises a polarizer configured to transmit the first output light and block the second output light.

10. The optical device of claim 9, wherein: the first out-coupling element is configured to couple out a first polarization component of the second light from the first light guide during a second sub-frame of the display frame as a third output light, the second out-coupling element is configured to couple out a second polarization component of the second light from the second light guide during the second sub-frame as a fourth output light, the polarization switch is configured to change the polarization of the third output light and change the polarization of the fourth output light during the second sub-frame, and the polarizer is configured to block the third output light and transmit the fourth output light.

11. The optical device of claim 1, wherein: the first light guide and the second light guide are a same single light guide, the first in-coupling element and the second in-coupling element are stacked together or disposed side-by-side at the single light guide, and the first out-coupling element and the second out-coupling element are stacked together or disposed side-by-side at the single light guide.

12. The optical device of claim 1, wherein: the first light guide and the second light guide are different light guides, the first in-coupling element and the first out-coupling element are connected to the first light guide, and the second in-coupling element and the second out-coupling element are connected to the second light guide.

13. The optical device of claim 1, further comprising: a light source assembly configured to emit the first light and the second light, wherein the first input field of view (FOV) is a first portion of a predetermined FOV and the second input FOV is a second portion of the predetermined FOV; and a display assembly configured to display the first output light and the second output light. a controller configured to control the light source assembly to emit the first light and the second light during a same subframe of a display frame or during two consecutive subframes of the display frame.

14. The optical device of claim 1, further comprising: a light source assembly configured to emit the first light and the second light, wherein each of the first input field of view (FOV) and the second input FOV corresponds to a substantially same predetermined FOV; and a controller configured to control the light source assembly to emit the first light and the second light during two consecutive subframes, respectively.

15. The optical device of claim 1, further comprising: a light source assembly configured to emit the first light and the second light, the light source assembly comprising a light source and a first polarization switch configured to switch a polarization of at least one of the first light or the second light emitted by the light source; a second polarization switch configured to switch a polarization of at least one of the first output light or the second output light; and a controller configured to synchronize an operational state of the first polarization switch and an operational state of the second polarization switch.

16. The optical device of claim 1, wherein: a combination of the first output FOV and the second output FOV is greater than at least one of the first input field of view (FOV) or the second input FOV.

17. A method for providing an extended field of view (FOV), the method comprising: coupling a first light having a first input FOV into a first light guide and coupling the first light out of the first light guide as a first output light having a first output FOV; and coupling a second light having a second input FOV into a second light guide and coupling the second light out of the second light guide as a second output light having a second output FOV, the second output FOV being substantially non-overlapping with the first output FOV; wherein a combination of the first output FOV and the second output FOV is greater than at least one of the first output FOV or the second output FOV, and the first light and the second light have orthogonal polarizations.

18. The method of claim 17, further comprising: generating the first light and the second light during a same subframe of a display frame; or generating the first light during a first subframe and generating the second light during a second subframe, the first subframe and the second subframe being consecutive subframes of a display frame. ​ ​ ​

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