Light emitting array with reflective polarizers for photonic cycling

Abstract

A lighting assembly may include a light source and a reflective polarizer overlapping the light source. A portion of the light incident on the reflective polarizer may not pass through the reflective polarizer and may be reflected back to the light source. The light source may include at least one of a light emitting diode (LED) light source, a micro LED light source, an organic light emitting diode (OLED) light source, a micro OLED light source, a liquid crystal on silicon (LCoS) light source, or an fLCoS light source. The reflective polarizer may include a polymeric birefringent multilayer structure having a plurality of first layers and a plurality of second layers alternating. The plurality of first layers may each include an isotropic polymer film and the plurality of second layers may each include an anisotropic polymer film. Various other devices, systems, and methods are also disclosed.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 381,555, filed on October 29, 2022, the disclosure of which is incorporated by reference in its entirety. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The accompanying drawings illustrate several exemplary embodiments and are a part of the specification. Together with the following description, these drawings demonstrate and explain various principles of the present disclosure.

[0004] Figure 1A to Figure 1B is an illustration of an example system including a thin reflective polarizer overlapping a light emitting array, according to some embodiments.

[0005] FIG. 2A to FIG. 2C are top and side views of an example lighting assembly having a reflective polarizer overlapping a light-emitting diode (LED) according to some embodiments.

[0006] Figure 3 is a schematic diagram of an example system including a thin reflective polarizer overlapping a light emitting array, according to some embodiments.

[0007] FIG. 4A to FIG. 4B is a graphical representation of polarized light emitted from a light emitting component according to some embodiments.

[0008] FIG. 5A to FIG. 5C is a cross-sectional view of a conformal reflective polarizer film overlaid with various LED surfaces according to some embodiments.

[0009] FIG. 6A to FIG. 6C Included are schematic diagrams showing example light emitting components and spectra of polarized light emitted from the components according to some embodiments.

[0010] 7A to 7D Included are diagrams showing example broadband reflective polarizer designs for use with multicolor lighting assemblies according to some embodiments.

[0011] Fig. 8A A cross-sectional view of an example liquid crystal device including a reflective polarizer is shown according to some embodiments.

[0012] Figure 8B A cross-sectional view of an example reflective polarizer disposed between two peelable skin layers is shown in accordance with some embodiments.

[0013] Fig.9AA cross-sectional view of a reflective polarizer stack having two reflective polarizer layers disposed between a pair of peelable skin layers is shown in accordance with some embodiments.

[0014] Fig. 9B shows an overlapping micro LED array according to some embodiments Fig.9A Cross-sectional view of an example reflective polarizer stack.

[0015] Fig. 10A A cross-sectional view of an example conformal reflective polarizer overlaid with an array of micro-LEDs is shown in accordance with some embodiments.

[0016] Fig. 10B A cross-sectional view of an example conformal reflective polarizer overlaid with an array of micro-LEDs is shown in accordance with some embodiments.

[0017] Fig. 10C A cross-sectional view of an example conformal reflective polarizer overlaid with an array of micro-LEDs having a fill resin disposed between raised areas of the array in accordance with some embodiments is shown.

[0018] Fig.11 is a flow chart of an exemplary method for forming a reflective polarizer assembly according to some embodiments.

[0019] Fig.12 is an illustration of exemplary augmented reality glasses that may be used in conjunction with embodiments of the present disclosure.

[0020] Fig.13 is an illustration of an exemplary virtual reality headset that can be used in conjunction with embodiments of the present disclosure.

[0021] In all drawings, the same reference numerals and descriptions refer to similar but not necessarily identical elements. Although the exemplary embodiments described herein are susceptible to various modifications and alternative forms, a number of specific embodiments have been shown in the drawings by way of example, and these specific embodiments will be described in detail herein. However, the exemplary embodiments described herein are not intended to be limited to the specific forms disclosed. Instead, the present disclosure covers all modifications, equivalents, and alternatives that fall within the scope of the appended claims. DETAILED DESCRIPTION

[0022] Artificial reality devices (e.g., virtual reality (VR) and augmented reality (VR) eye-mounted devices or head-mounted devices) can enable users to experience a variety of events, such as interacting with people in a computer-generated three-dimensional world simulation or viewing data superimposed on a real-world view. As an example, superimposing information on the field of view can be achieved through an optical head-mounted display (OHMD) or by using embedded wireless glasses with a transparent heads-up display (HUD) or augmented reality (AR) overlay. VR / AR eye-mounted devices and VR / AR head-mounted devices can be used for various purposes. For example, governments can use such devices for military training, medical professionals can use such devices to simulate surgery, and engineers can use such devices as design visualization aids.

[0023] These and other applications can take advantage of one or more characteristics of polymers and / or other tailored materials to improve optical and structural characteristics in a beneficial manner. For example, the refractive index can be selectively tuned to manipulate light, the thermal conductivity can be adjusted to manage heat, and the mechanical strength and toughness can be enhanced to provide lightweight structural supports. In various applications, optical elements and other components can include polymer films having anisotropic mechanical properties and / or anisotropic optical properties.

[0024] For traditional AR / VR displays based on light-emitting diodes (LEDs), it is usually necessary to use polarized light. This polarized light can be used, for example, for pancake lenses, waveguide displays, etc. However, the light emitted directly from the LED is usually unpolarized, and adding a common polarizer can reduce its efficiency by 50% or more, resulting in heat absorption and increased overall power requirements of the head-mounted device. It is best for LEDs to have more efficient polarization and lower unused light losses.

[0025] In various examples described herein, polymer films exhibiting optical anisotropy can be incorporated into various systems and devices, including birefringent gratings, reflective polarizers, optical compensators, and optical retarders for systems using polarized light (e.g., liquid crystal displays (LCDs)). For example, reflective polarizers can be used in display-related applications to enhance brightness within display systems that use polarized light as described herein. In some embodiments, a reflective polarizer can be used to recycle light so that approximately 50% of the light emitted from an LED (or micro-LED, OLED, etc.) (e.g., the non-polarized portion of the light) is reflected back to the LED light source through the reflective polarizer. The reflected light photons can be partially reabsorbed by the LED, which then re-emits more non-polarized photons in response to the reabsorption of the light. This process can be repeated multiple times, thereby improving the efficiency of the LED and ensuring that the output light is polarized, while non-polarized light is continuously recycled.

[0026] The system efficiency may be limited by the reabsorption and re-emission of the LED semiconductor. In the system disclosed herein, the reflective polarizer is composed of, for example, an extremely thin birefringent extruded multilayer polymer. This reflective polarizer polymer layer can not only be located on top of the LED surface, but can also form a conformal coating on the surface of the microlens in contact with the LED. Such microlenses can include, for example, a lens array for collimating and / or changing the divergence of the LED.

[0027] The following will refer to Figures 1A to 10C A detailed description of a reflective polarizer and a light emitting system including a reflective polarizer for improving efficiency through photon recycling is provided. Fig.11 and Fig.12 A related discussion relates to exemplary virtual reality devices and augmented reality devices that may include one or more multilayer polymer films as disclosed herein.

[0028] Figure 1A to Figure 1B An example system 100 is shown that includes a thin reflective polarizer 102 overlapping a light emitting array 104 in accordance with some embodiments. Figure 1A As shown, a large portion (e.g., approximately 50%) of the emitted light 108 emitted from the light sources (e.g., LEDs 106) of the light emitting array 104 may not pass through the thin film reflective polarizer 102, as shown. Instead, a large portion of the light 108 that is not sufficiently polarized to pass through the reflective polarizer 102 may be reflected back toward the LEDs 106, as shown. For example, Figure 1BAs further shown, a significant portion of the emitted light 108 that is reflected back by the reflective polarizer 102 may be reabsorbed by the LED 106. The reabsorbed light may then be re-emitted again from the LED 106. At least a portion of the light re-emitted by the LED 106 may pass through the reflective polarizer 102, with the remainder being reflected again back to the LED 106 of the light emitting array 104 to be re-absorbed and re-emitted. The light from the LED 106 may undergo this reflection, re-absorption, re-emission process multiple times, resulting in a larger amount of polarized light 110 ultimately passing through the reflective polarizer 102. As a result, the lighting efficiency of the LED / reflective polarizer assembly of the system 100 may be significantly higher than conventional polarized lighting assemblies, wherein the disclosed assembly provides higher illumination without increasing power consumption.

[0029] The reflective polarizer films described herein, such as the reflective polarizer films used in reflective polarizer 102, can be formed in any suitable manner. In some examples, the reflective polarizer film can include a stack of one layer or multiple layers. These layers can include, for example, a polymer layer or multiple overlapping polymer layers. The applied stress can be used to form a preferred arrangement of crystals or polymer chains within the polymer film and cause corresponding changes in optical, thermal and / or mechanical properties along different directions of the film. As further disclosed herein, during the process of stretching the polymer film to cause the preferred arrangement of crystals / polymer chains and the accompanying changes in refractive index / birefringence, thermal and mechanical properties, extrusion techniques can be used to reduce the propensity of polymer chain entanglement within the extruded film.

[0030] Single or multiple stretching events can be used to stretch the polymer film or polymer multilayer of extrusion.Some stretching processes can include two continuous stretching events.For example, orthogonal consecutive stretching (orthogonal consecutive stretching, OCS) can be used to develop structural fingerprints, such as less than the stretching ratio for obtaining similar structural fingerprints by contrasting single stretching (single stretching, SS) technology or parallel consecutive stretching (parallel consecutive stretching, PCS) technology. The polymer chain orientation of the smaller layer thickness and a higher degree. Orthogonal consecutive stretching can include firstly along the first in-plane axis stretching polymer film, and then next along the second in-plane axis orthogonal to the first in-plane axis stretching this polymer film.

[0031] Stretching can include a single stretching action or multiple continuous stretching events such as along different in-plane directions of the polymer film. The stretching action can be speed-limited or strain rate-limited. In some embodiments, the polymer film can be stretched at a variable speed or a constant speed. In some embodiments, a variable strain rate or a constant strain rate (e.g., 0.5 / second, 1 / second, 5 / second or 10 / second, including the range between any of the aforementioned values) can be used to stretch the polymer film. As an example, the strain rate can be reduced to a final strain rate (e.g., 0.5 / second) from an initial strain rate (e.g., 5 / second) throughout the stretching action and / or in different stretching events.

[0032] During the stretching action, the crystalline content in the polymer film can increase. In some embodiments, stretching can change the orientation of crystals within the polymer film without substantially changing the crystalline content.

[0033] The polymer film can be uniaxially oriented or biaxially multilayer oriented to form a reflective polarizer. Anisotropic polymer films can be formed using a film orientation system that is configured to heat and stretch the polymer film in at least one in-plane direction in one or more different regions of the polymer film. In some embodiments, the film orientation system can be configured to stretch the polymer film (i.e., a crystallizable polymer film) only along an in-plane direction. For example, the film orientation system can be configured to apply in-plane stress to the polymer film along the x direction while allowing the film to relax along the orthogonal in-plane direction (e.g., along the y direction). As used herein, in some examples, the relaxation of the polymer film can be accompanied by the absence of applied stress along the relaxation direction.

[0034] According to some embodiments, within an example orientation system, a polymer film may be heated and stretched transversely to the direction in which the film travels through the system. In such embodiments, the polymer film may be held along opposite edges by a plurality of removable clamps or other suitable fasteners or mounting features that may be slidably disposed along a divergent track system, such that the polymer film is stretched in a transverse direction (TD) as the polymer film moves through the heating and deformation zone of the film orientation system in a machine direction (MD). In some embodiments, the stretching rate in the transverse direction and the relaxation rate in the machine direction may be independently and locally controlled. In certain embodiments, large-scale production may be achieved, for example, using a roll-to-roll manufacturing platform.

[0035] In various examples, the degree of relaxation perpendicular to the stretching direction can be approximately equal to the square root of the stretch ratio in the stretching direction. In some embodiments, the degree of relaxation can be substantially constant throughout the stretching process. In other embodiments, the degree of relaxation can decrease, wherein a greater relaxation is associated with the beginning of the stretching step and a smaller relaxation is associated with the end of the stretching step.

[0036] After the polymer film is deformed, a thermal setting may be applied to the film. The thermal setting temperature may be less than, equal to, or greater than the orientation temperature, but higher than the glass transition temperature of the polymer. The thermal setting may be a constant strain or a variable strain. The polymer film may be cooled after the thermal setting. The cooling action may include allowing the polymer film to cool naturally at a set cooling rate, or cooling by quenching (e.g., by purging with a cryogenic gas), which may thermally stabilize the polymer film.

[0037] The disclosed polymer films can have the characteristics of optical quality polymer films and can be formed into or incorporated into optical elements, such as thin film reflective polarizers, such as Figure 1A and Figure 1B 1. The reflective polarizer 102 shown in FIG. The optical elements can be used in various types of display devices, such as virtual reality and augmented display glasses and head-mounted devices. The efficiency of these and other optical elements can correspond at least in part to optical transparency, thermal conductivity, and / or mechanical response.

[0038] As used herein, the terms "polymer film" and "polymer layer" may be used interchangeably. Furthermore, unless the context clearly indicates otherwise, reference to a "polymer film" or "polymer layer" may include reference to a "multilayer polymer film".

[0039] According to various embodiments, the optical element may include a reflective polarizer co-integrated with an anti-reflective coating configured to reduce the reflectivity of visible light and infrared (IR) radiation at least along and / or near the transmission axis of the reflective polarizer. In various embodiments, the reflective polarizer may include a stack of alternating isotropic polymer layers and anisotropic polymer layers, and the anti-reflective coating may include one or more polymer layers with a high refractive index and one or more polymer layers with a low refractive index arranged in an alternating ABAB structure.

[0040] In certain embodiments, a reflective polarizer stack and, optionally, an anti-reflective coating (ARC) can be co-extruded in a single-step process that reduces manufacturing complexity and avoids orange peel defects and undesirable reflectivity fluctuations along the blocking axis relative to comparative processes.

[0041] The optical properties of a reflective polarizer, or a reflective polarizer and anti-reflective coating (RP-ARC) multilayer stack, can be tuned by applying in-plane stress to the multilayer, which causes alignment of crystallites within the film and concomitant changes in refractive index and birefringence. For example, for augmented reality / virtual reality applications, RP-ARC multilayers can be laminated on a transparent substrate (e.g., a zoom lens).

[0042] In some embodiments, a sacrificial polymer layer can be coextruded with the RP-ARC stack to coat and protect the terminal layers within the multilayer stack. In some examples, the harmful effects of direct contact between the extrusion die and the functional terminal layers of the multilayer extrudate can be overcome by incorporating one or more sacrificial layers that are configured to substantially absorb surface damage caused by the die. Such sacrificial layers can be removed after the polymer layers are stretched and oriented but before being laminated to the substrate.

[0043] Example sacrificial layers may include low surface energy polymers (polymers S) (e.g., polydimethylsiloxane, polypropylene, polyethylene, ethylene-vinyl acetate, polyoxymethylene, polystyrene, polyvinyl alcohol), and fluorinated polymers (e.g., polytetrafluoroethylene and polyvinylidene fluoride), and combinations and copolymers thereof. In certain embodiments, the sacrificial layer may be configured as a peelable skin layer and may have a surface energy of less than about 38 dyne / cm.

[0044] In at least one embodiment, the first polymer film of the multilayer reflective polarizer stack can be optically isotropic, wherein n x =n y =n z and may include a first polymer composition, namely polymer A. In certain embodiments, the first polymer film may be characterized by a refractive index n x <1.8, n y <1.8, and n x -n y <0.1.

[0045] The first polymer film may include one or more polymers synthesized from at least one acid monomer and at least one alcohol monomer. Example acids include naphthalene dicarboxylic acid, terephthalic acid, isophthalic acid, azelaic acid, norbornene dicarboxylic acid, and other dicarboxylic acids. Suitable acids may be polymerized with glycols including ethylene glycol, diethylene glycol, propylene glycol, butanediol, cyclohexanedimethanol, polyethylene glycol, and dihydrogen organic compounds, and the like, as well as combinations and derivatives thereof, including isomers and copolymers thereof.

[0046] The second polymer film of the multilayer reflective polarizer stack may include a crystalline or semi-crystalline optically anisotropic polymer, wherein the refractive index of each layer is, for example, determined according to n x >n y >n z or x >n y =n z and may include a second polymer composition, namely polymer B. In certain embodiments, the second polymer film may be characterized by n x >1.8 and n x -n y >0.1 (e.g., n x >1.85 and n x -n y >0.2). In certain embodiments, the refractive indices of adjacent layers (eg, the first film and the second film) are equal along a common direction (eg, n y (film 1) = n y (Film 2)) can achieve high contrast.

[0047] The second polymer film may, for example, include polyethylene naphthalate, polyethylene terephthalate, polyethylene isophthalate, polybutylene naphthalate, polybutylene terephthalate, polyoxymethylene, and aliphatic or semi-aromatic polyamides. In some cases, polymer B may also include one or more oligomers as described above. The molecular weight of the oligomer may be less than about 50% of the molecular weight of the polymer, for example, less than about 30%, less than about 10%, less than about 5%, or less than about 1% of the molecular weight of the polymer. In some cases, polymer B may include a nucleating agent, for example, talc, sodium benzoate, or an ionomer.

[0048] Although the reflective polarizer stack is described above as having two polymer layers, it will be appreciated that the total number of layers making up the reflective polarizer stack and any ARC stack formed on top can be independently selected to be any integer greater than 2. For example, the reflective polarizer stack can include 3 or more polymer layers, e.g., 3, 10, 100, 200, 300, 400, 500, or more layers, and the overlapping ARC can include 3 or more polymer layers, e.g., 3, 10, 20, 30, 40, 50, or more layers.

[0049] After the polymer crystals are oriented and one or more sacrificial layers are removed, the multilayer polymer film can be laminated onto an optical substrate (eg, glass or polymer lens). FIG. 2A to FIG. 2C A top view and a cross-sectional side view of an example lighting assembly having a reflective polarizer overlapping an LED are shown in accordance with some embodiments. Figure 2A An assembly 200A is shown that includes a reflective polarizer layer 212 overlying a single LED 214 . Figure 2B An assembly 200B is shown that includes a reflective polarizer layer 212 disposed on a multicolor LED structure 216B having a plurality of LEDs 214 (eg, red, green, red, blue (RGRB) LEDs). Figure 2C An assembly 200C is shown that includes a reflective polarizer layer 212 disposed on a multicolor LED structure 216C having a plurality of LEDs 214 (eg, red, green, blue (RGB) LEDs).

[0050] Figure 3 3 is a schematic diagram of an example system 300 including a thin reflective polarizer 312 overlapping a light emitting array 302, according to some embodiments. As shown, three example LED light sources 306 can transmit light through the reflective polarizer 312 toward, for example, a screen 318. In this example, up to about 50% of the light emitted from the three example LED light sources 306 can be reflected from the thin reflective polarizer 312, reabsorbed by the three example LED light sources 306, and then re-emitted by the LED light sources 306.

[0051] Figure 4A and Figure 4B shows the polarized light emitted from the light emitting component, such as Figure 3 shown. Figure 4AAn example of an idealized polarized light emission scenario is shown, where all light from an array of three LED light sources is polarized. The graph shows the light intensity in W / mm^2 along the length (X) and width (Y) dimensions of the light emitting area. As shown, in this ideal case, the emitted light area can have generally regular boundaries corresponding to the LED shape outline and contained within the limited viewing area of ​​the array.

[0052] Figure 4B A more realistic pattern of polarized light emission scenarios is shown, where approximately 50% of the light is emitted by the reflective polarizer (RP) / LED system described herein (see, e.g., Figure 3 300) as shown in FIG. Figure 4B As shown, the system can reflect light from the array over a wide horizontal field of view, such as about 40 degrees. The graph shows the light intensity in W / mm^2 along the length (X) dimension and the width (Y) dimension of the light emitting area. As shown in the figure, in this more realistic case, the area of ​​emitting light can be larger than Figure 4A The ideal scenario shown in is diffused to a greater extent.

[0053] FIG. 5A to FIG. 5C is a cross-sectional view of a conformal reflective polarizer film overlaid with various LED surfaces according to some embodiments. Figure 5A Light emitting assembly 500A is shown and includes a reflective polarizer layer 512 overlying a substantially planar surface, such as a planar surface of layer 520A covering an LED array 516 . Figure 5B and Figure 5C Light emitting components 500B and 500C are shown, and light emitting components 500B and 500C include a reflective polarizer layer 512 overlapping a non-uniform surface. For example, Figure 5B A reflective polarizer layer 512 is included that overlaps a curved surface of a lens 520B disposed over an LED array 516 . Figure 5C A reflective polarizer layer 512 is included that overlaps a roughened LED surface (eg, a wavy surface) of a microlens array 520C disposed over an LED array 516 .

[0054] Fig. 6A A cross-sectional view of a light emitting component 600 having a multilayer reflective polarizer 612 (n1 and n2 stack) is shown. As shown, the light emitting component 600 can be disposed between an incident material 622 that transmits incident light from an LED and a substrate material 624. Figure 6BSpectra of polarized light emitted from a light emitting assembly (e.g., light emitting assembly 600 including a multilayer reflective polarizer) are shown. As shown, P-polarized light can effectively pass through the example reflective polarizer, particularly within selected wavelengths. On the other hand, S-polarized light can be effectively blocked and reflected over a wide spectrum, such as Figure 6C shown.

[0055] 7A to 7D An example broadband reflective polarizer design is shown for use with a multi-color (eg, RGB) lighting assembly. Fig. 7A and Figure 7C For example, Figure 7B and Fig.7D p-polarized light reflection characteristics (wavelength / incident) of the multilayer reflective polarizer shown in . Figure 7B The reflective polarizer shown in can have a total thickness of about 7 μm, with the thickness of about 90 stacked layers increasing as shown. Fig.7D The reflective polarizer shown in can have a total thickness of about 4 μm, with the thickness of about 60 stacked layers varying as shown.

[0056] Fig. 8A 8 is a cross-sectional view of an example liquid crystal device 800 (e.g., a silicon-based liquid crystal (i.e., LCoS, silicon-based ferroelectric liquid crystal (fLCoS)) device) including a reflective polarizer 812. As shown in the figure, the reflective polarizer 812 can be, for example, overlapped with a reflective silicon layer 832 disposed on a substrate 830. The reflective polarizer 812 can reflect light from the substrate 830 that is not polarized in a selected direction. The light reflected from the reflective polarizer 812 can be reflected again by the reflective silicon layer 832. Only light that is ultimately polarized in a selected direction can pass through the reflective polarizer 812 to the liquid crystal layer 834. Therefore, the efficiency of appropriately polarized light passing through the reflective polarizer 812 and the liquid crystal 834 layer can be improved. The polarized light that passes through the reflective polarizer 812 and the liquid crystal layer 834 can be selectively polarized to easily pass through the polarizer 836.

[0057] Figure 8BA cross-sectional view of an assembly 850 is shown, which includes a reflective polarizer 812 disposed between two removable layers 852 and 854 (i.e., peelable skins). In some examples, the ultra-thin reflective polarizer 812 may include two removable layers 852 and 854 on both sides of the reflective polarizer 812 to protect the reflective polarizer 812 during the film formation process and the downstream lamination process. Examples of removable layers 852 and 854 may include low surface energy polymers (e.g., polydimethylsiloxane, polypropylene, polyethylene, ethylene-vinyl acetate, polyoxymethylene, polystyrene, polyvinyl alcohol), and fluorinated polymers (e.g., polytetrafluoroethylene and polyvinylidene fluoride), and their compositions and copolymers. In some embodiments, the sacrificial layer may be configured as a removable layer and may have a surface energy of less than about 38 dynes / cm. In other cases, a release coating, such as an adhesive layer, may be added between each removable layer 852 and 854 and the reflective polarizer 812.

[0058] In at least one example, removable layers 852 and 854 can be coextruded with reflective polarizer 812. Additionally or alternatively, removable layers 852 and 854 can be solvent coated on reflective polarizer 812 after forming reflective polarizer 812. Solvent coating can be by blade coating, spray coating, or dip coating. In other cases, removable layers 852 and 854 can be added by vapor deposition after forming reflective polarizer 812.

[0059] In various embodiments, in order to avoid pixel crosstalk and / or interference, a pattern can be made on top of the reflective polarizer. Such a pattern can be designed based on the pixel distance and the light source position. For example, the pattern can simply be one or more repeated rectangles or circles. The pattern can be embossed onto the film, for example, by passing through a patterned cold roller immediately after the film is extruded. The pattern can be embossed after the reflective polarizer is formed by high temperature stamping. The pattern can also be formed by laser cutting patterning or blade cutting patterning. Any other suitable patterning technology can be used additionally or alternatively.

[0060] Fig.9AA cross-sectional view of an assembly 950 according to some embodiments is shown, the assembly 950 including a reflective polarizer stack 912 having at least two reflective polarizer layers or regions disposed between a pair of removable layers 952 and 954. In some cases, the reflective polarizer stack 912 may have two regions (e.g., two regions in two or more separate reflective polarizer layers, as shown). For example, one region may be a high-angle reflection region 912A that reflects high-angle light from a light source. Another region may be, for example, a normal-angle reflection region 912B that reflects light at a normal angle and / or close to a normal angle from a light source. In various examples, the high-angle reflection region 912A that reflects high-angle light may be closer to the light source, while the normal-angle reflection region 912B that reflects light close to a normal angle may be further away from the light source.

[0061] Fig. 9B A cross-sectional view of an assembly 960 including an array of micro-LEDs 962 overlapping therewith is shown in accordance with some embodiments. Fig.9A As shown, removable layers 952 and / or 954 can be removed during or before securing reflective polarizer stack 912 to micro LED array 962. In some cases, reflective polarizer stack 912 can be conformal to a light source, including a light source with an uneven surface.

[0062] In some embodiments, Fig. 10A The micro LED array assembly 1000 and Fig. 10B As shown in the micro LED array assembly 1010 , the reflective polarizer 1012 can conform to the uneven surface of the micro LED array 1016 .

[0063] In at least one embodiment, Fig. 10C As shown, the reflective polarizer 1012 may not conform to the uneven surface of the micro LED array 1016. In this example, the space between the uneven surface portion of the micro LED array 1016 and the reflective polarizer 1012 (e.g., the space between the micro lenses or other surface features) can be filled with a filling material (e.g., resin 1070) as shown.

[0064] An integrated polarization recycling system may include an LED-based light source and a thin polymer reflective polarizer for enhancing the polarization light emission efficiency. The light source may include, but is not limited to, LEDs, micro-LEDs, OLEDs, micro-OLEDs, LCoS, and fLCoS. The thin polymer may be made of a polymer birefringent multilayer structure. The multilayer structure may include a plurality of alternating first polymer layers and a plurality of second polymer layers, each of the plurality of first polymer layers having a polymer film with in-plane refractive indices of n1x and n1y, and each of the plurality of second polymer layers having a polymer film with in-plane refractive indices of n2x and n2y, where n1x = n1y, and n2x < n2y or n2y < n2x. Wherein, n1x < 1.8, n1y < 1.8, │n1x - n1y│ < 0.1, n2y > 1.5, and │n2x - n2y│ > 0.05 (in some cases, │n2x - n2y│ > 0.1). The total thickness of the reflective polarizer may be less than 0.5h, where h is the height of the semiconductor component of the LED. The spectral bandwidth of the reflective polarizer may be at least 1.1 times as large as, but not greater than 2 times, the spectral bandwidth of the LED, and the central wavelength emitted by the LED matches the central wavelength designed for the reflective polarizer. The reflective polarizer may reflect more than 90% of the s-polarized light or p-polarized light while transmitting at least 85% of the other of the p-polarized light or s-polarized light. The outer surface of the LED may be covered with the reflective polarizer.

[0065] An integrated polarization recycling system may include a light source based on a group of LEDs and a thin polymer reflective polarizer for enhancing the polarization light emission efficiency. The light source may include, but is not limited to, LEDs, micro-LEDs, OLEDs, micro-OLEDs, LCoS, and fLCoS. The group of LEDs may include 2 to 6 LEDs. Each LED may emit a red spectral band, a green spectral band, or a blue spectral band. The spectral bandwidth of the reflective polarizer may be broadband and cover at least the sum of the group of LEDs within the visible spectrum (400 nm to 720 nm). The thin polymer reflective polarizer may be made of a polymer birefringent multilayer structure. The multilayer structure may include a plurality of alternating first polymer layers and a plurality of second polymer layers, the plurality of first polymer layers each including a polymer film with in-plane refractive indices of n1x and n1y, and the plurality of second polymer layers each including a polymer film with in-plane refractive indices of n2x and n2y. Wherein, n1x = n1y and n2x < n2y or n2y < n2x. Wherein, n1x < 1.8, n1y < 1.8, │n1x - n1y│ < 0.1, n2y > 1.5, and │n2x - n2y│ > 0.3. The total thickness of the reflective polarizer may be less than 0.5h, where h is the height of the semiconductor component of the LED. The spectral bandwidth of the reflective polarizer may be at least 1 times larger than the spectral bandwidth of the LED, but not more than 2 times that bandwidth. The reflective polarizer may reflect more than 90% of the s-polarized light or p-polarized light while transmitting at least 85% of the other of the p-polarized light or s-polarized light. The outer surface of the LED or the group of LEDs may be covered with the reflective polarizer.

[0066] An integrated polarization recycling system may include an LED-based light source, a thin polymer reflective polarizer for enhancing the polarization light emission efficiency, and an optical component attached to the LED to control the direction and divergence of the light of the LED. The light source may include, but is not limited to, an LED, a micro-LED, an OLED, a micro-OLED, an LCoS, and an fLCoS. The thin polymer reflective polarizer may be made of a polymer birefringent multilayer structure. The multilayer structure may include a plurality of alternating first polymer layers and a plurality of second polymer layers, the plurality of first polymer layers each including a polymer film with in-plane refractive indices of n1x and n1y, and the plurality of second polymer layers each including a polymer film with in-plane refractive indices of n2x and n2y. Wherein, n1x = n1y and n2x < n2y or n2y < n2x. Wherein, n1x < 1.8, n1y < 1.8, │n1x - n1y│ < 0.1, n2y > 1.5, and │n2x - n2y│ > 0.05. The total thickness of the reflective polarizer may be less than 0.5h, where h is the height of the semiconductor component of the LED. The spectral bandwidth of the reflective polarizer may be at least 1.1 times as large as the spectral bandwidth of the LED, but not greater than 3 times that bandwidth, and the central wavelength emitted by the LED matches the central wavelength designed for the reflective polarizer. The reflective polarizer may reflect more than 90% of the s-polarized light or p-polarized light, while transmitting at least 85% of the other of the p-polarized light or s-polarized light. The optical component may be a microlens, a metasurface, a diffractive component, or a surface roughness for reducing total internal reflection (TIR). The microlens may be spherical, aspherical, or cylindrical, converging (with a focal length between 10 microns and 500 microns) or diverging light (diverging from 0 degrees to 60 degrees). The optical component may be coated with a reflective polarizer film.

[0067] An ultra-thin reflective polarizer may include at least one peelable surface layer and a multilayer reflective polarizer less than about 15 um. The multilayer reflective polarizer may be less than 10 um. The surface layer may include a portion with a surface energy less than about 38 dynes / cm. A release coating may be added between the peelable surface layer and the reflective polarizer. The surface layer may include a portion selected from the group consisting of polyethylene, polypropylene, and fluorinated polymers. A patch pattern may be included on the surface of the reflective polarizer to avoid pixel crosstalk.

[0068] The reflective polarizer can reflect high-angle light closer to the emission surface and can reflect low-angle light away from the emission surface. The reflective polarizer can have a first major surface, a second major surface, and a thickness, wherein the reflective polarizer has a first reflective polarizer region and a second reflective polarizer region, the first reflective polarizer region is adjacent to the first major surface, and the second reflective polarizer region is adjacent to the first reflective polarizer region. The first reflective polarizer region can preferentially reflect at least one of red light, green light, and blue light at an incident angle of about 45 degrees from the first major surface in air to the normal, and the second reflective polarizer region can preferentially reflect at least one of red light, green light, and blue light at an incident angle between about 0 degrees and about 20 degrees. The thickness between the first major surface and the nearest point of the reflective polarizer region can be less than about 10 microns (e.g., about 5 microns, about 2 microns). The spacing between the first reflective polarizer region and the second reflective polarizer region can be less than about 10 microns (e.g., about 5 microns, about 2 microns). The reflective polarizer can include a multilayer optical film made of at least one birefringent polymer layer, or a cholesteric reflective polarizer, or a combination thereof.

[0069] A reflective polarizer with low thickness may have a first major surface and a second major surface, wherein at least the first major surface is within about 10 microns, 5 microns, 2 microns, or 1 micron of the reflective polarizer. The method of manufacturing such a reflective polarizer may include forming a reflective polarizer having an alternating stack of a first polymer and a second polymer, the first polymer forming a high birefringence, the second polymer forming a relatively low birefringence, wherein there is a releasable layer between at least the first major surface and the reflective polarizer stack. The releasable layer may be located between the reflective polarizer and the surface layer forming the first major surface. The releasable layer may include a fluorinated polymer (the fluorinated polymer includes one of PVDF, PFE), a copolymer, polyethylene, polypropylene, cycloolefin polymers and copolymers, and mixtures thereof. The releasable layer may form a surface layer.

[0070] Fig.11 1 is a flow chart illustrating a method 1100 of manufacturing a reflective polarizer assembly according to at least one embodiment of the present disclosure. Fig.11 As shown, at operation 1110, a reflective polarizer can be formed by forming an alternating stack of at least one first polymer layer and at least one second polymer layer, wherein the at least one first polymer layer has a first birefringence and the at least one second polymer layer has a second birefringence that is different from the first birefringence.

[0071] At operation 1120, an adhesive layer may be formed on at least one surface of the reflective polarizer.

[0072] At operation 1130, a removable layer may be disposed on the adhesive layer.

[0073] Exemplary embodiment

[0074] Example 1: An illumination assembly includes a light source and a reflective polarizer that overlaps with the light source, wherein a portion of the light incident on the reflective polarizer does not pass through the reflective polarizer and is reflected back to the light source.

[0075] Example 2: The display system according to Example 1 further includes an optical element disposed between the light source and the reflective polarizer, wherein the optical element is coupled to the light source and the optical element is covered by the reflective polarizer.

[0076] Example 3: The display system according to any one of Examples 1 and 2, wherein the light reflected back to the light source is reabsorbed by the light source, and in response to the reabsorbed light, the light source re-emits light to the reflective polarizer.

[0077] Example 4: The display system according to any one of Examples 1 to 3, wherein the light source includes at least one of a light emitting diode (LED) light source, a micro-LED light source, an organic light emitting diode (OLED) light source, a micro-OLED light source, a liquid crystal on silicon (LCoS) light source, or a fLCoS light source.

[0078] Example 5: The display system according to any one of Examples 1 to 4, wherein the reflective polarizer includes a thin polymer reflective polarizer.

[0079] Example 6: The display system according to Example 5, wherein the thin polymer reflective polarizer includes a polymer birefringent multilayer structure.

[0080] Example 7: The display system according to Example 6, wherein 1) the birefringent multilayer structure includes a plurality of alternating first layers and a plurality of second layers, 2) each of the plurality of first layers includes an isotropic polymer film having in-plane refractive indices of n x (1) and n y (1), and each of the plurality of second layers includes an anisotropic polymer film having in-plane refractive indices of n x (2) and n y (2), 3) n1x = n1y and n2x < n2y or n2y < n2x, and 4) n1x < 1.8, n1y < 1.8, │n1x - n1y│ < 0.1, n2y > 1.5, and │n2x - n2y│ > 0.05.

[0081] Example 8: The display system according to Example 7, wherein │n2x - n2y│ > 0.1.

[0082] Example 9: A display system as described in Example 6, wherein the birefringent multilayer structure has an average reflectivity of less than about 1% in the range of 400nm to 700nm along the passing direction, and has an average reflectivity of at least about 90% in the range of 400nm to 700nm along the blocking direction.

[0083] Example 10: A display system as described in any of Examples 1 to 9, wherein the total thickness of the reflective polarizer is less than 0.5h, where h is the height of the semiconductor component of the LED.

[0084] Example 11: A display system as described in any of Examples 1 to 10, wherein the spectral bandwidth of the reflective polarizer is at least 1.1 times larger than the spectral bandwidth of the LED, but not greater than 2 times the bandwidth, and the central wavelength emitted by the LED matches the central wavelength of the reflective polarizer.

[0085] Example 12: A display system as described in any of Examples 1 to 11, wherein the reflective polarizer reflects more than 90% of one of the s-polarized light or the p-polarized light while transmitting at least 85% of the other of the s-polarized light or the p-polarized light.

[0086] Example 13: The display system of any of Examples 1 to 12 further includes a sacrificial layer disposed directly on the reflective polarizer, wherein the sacrificial layer includes a portion having a surface energy less than about 38 dynes / cm.

[0087] Example 14: A display system as described in any of Examples 1 to 13, wherein the light source includes a group of 2 to 6 LEDs, and each LED emits at least one of red spectrum light, green spectrum light, or blue spectrum light.

[0088] Example 15: A display system as described in Example 14, wherein the spectral bandwidth of the reflective polarizer is broadband and covers at least the sum of the LED groups in the visible spectrum of about 400nm to 720nm.

[0089] Example 16: A display system as described in any of Examples 14 and 15, wherein the spectral bandwidth of the reflective polarizer is at least 1 times larger than the spectral bandwidth of the LED, but not greater than 2 times the bandwidth.

[0090] Example 17: The color conversion unit of any of Examples 1 to 16 further comprising at least one removable layer overlapping a surface of the reflective polarizer.

[0091] Example 18: A reflective polarizer comprises a first major surface, a second major surface, a first reflective polarizer region, and a second reflective polarizer region, wherein 1) the first reflective polarizer region is adjacent to the first major surface, 2) the second reflective polarizer region is adjacent to the first reflective polarizer region, 3) the first reflective polarizer region preferentially reflects at least one of red light, green light, or blue light from the first major surface at an incident angle of approximately 30 to 60 degrees from the normal in air, and 4) the second reflective polarizer region reflects at least one of red light, green light, or blue light at an incident angle of approximately 0 to 20 degrees from the normal in air.

[0092] Example 19: A method comprising: forming a reflective polarizer by forming an alternating stack of at least one first polymer layer and at least one second polymer layer, wherein the at least one first polymer layer has a first birefringence and the at least one second polymer layer has a second birefringence that is different from the first birefringence; and forming an adhesive layer on at least one surface of the reflective polarizer.

[0093] Example 20: The method as described in Example 19, further comprising: disposing a removable layer on the adhesive layer.

[0094] Embodiments of the present disclosure may include various types of artificial reality systems, or be implemented in combination with various types of artificial reality systems. Artificial reality is a form of reality that has been adjusted in some way before being presented to the user, and artificial reality may include, for example, virtual reality, augmented reality, mixed reality, hybrid reality, or some combination and / or derivative thereof. Artificial reality content may include content generated entirely by a computer or computer-generated content combined with collected (e.g., real-world) content. Artificial reality content may include video, audio, tactile feedback, or some combination thereof, any of which may be presented in a single channel or multiple channels (e.g., stereoscopic video that produces a three-dimensional (3D) effect to the observer). In addition, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof, which are used, for example, to create content in artificial reality and / or to be used in artificial reality in other ways (e.g., to perform activities in artificial reality).

[0095] Artificial reality systems can be implemented in a variety of different form factors and configurations. Some artificial reality systems can be designed to operate without the use of a near-eye display (NED). Other artificial reality systems can include a NED that also provides visibility of the real world (e.g., Fig.12 ) or an NED that visually immerses a user in an artificial reality (e.g., Fig.13 1300 in the virtual reality system 1300). While some artificial reality devices may be stand-alone systems, other artificial reality devices may communicate and / or coordinate with external devices to provide an artificial reality experience to a user. Examples of such external devices include handheld controllers, mobile devices, desktop computers, devices worn by a user, devices worn by one or more other users, and / or any other suitable external system.

[0096] The augmented reality system 1200 may include an eye-mounted device 1202 having a frame 1210 configured to hold a left display device 1215(A) and a right display device 1215(B) in front of the user's eyes. The display device 1215(A) and the display device 1215(B) may operate together or independently to present an image or a series of images to the user. Although the augmented reality system 1200 includes two displays, embodiments of the present disclosure may be implemented in an augmented reality system having a single NED or more than two NEDs.

[0097] In some embodiments, the augmented reality system 1200 may include one or more sensors, such as sensor 1240. Sensor 1240 may generate a measurement signal in response to the movement of the augmented reality system 1200 and may be located substantially on any portion of the frame 1210. Sensor 1240 may represent one or more of a variety of different sensing mechanisms, such as a position sensor, an inertial measurement unit (IMU), a depth camera assembly, a structured light emitter and / or detector, or any combination thereof. In some embodiments, the augmented reality system 1200 may include or exclude sensor 1240, or may include more than one sensor. In embodiments where sensor 1240 includes an IMU, the IMU may generate calibration data based on the measurement signal from sensor 1240. Examples of sensor 1240 may include, but are not limited to, an accelerometer, a gyroscope, a magnetometer, other suitable types of sensors that detect movement, sensors for error correction of an IMU, or some combination thereof.

[0098] In some examples, the augmented reality system 1200 may also include a microphone array having a plurality of acoustic transducers 1220 (A) to 1220 (J), which are collectively referred to as acoustic transducers 1220. Acoustic transducers 1220 may represent a transducer that detects changes in air pressure caused by sound waves. Each acoustic transducer 1220 may be configured to detect sound and convert the detected sound into an electronic format (e.g., an analog format or a digital format). Fig.12 The microphone array in may include, for example, ten acoustic transducers: acoustic transducers 1220(A) and 1220(B) that can be designed to be placed in corresponding ears of a user; acoustic transducers 1220(C), 1220(D), 1220(E), 1220(F), 1220(G) and 1220(H) that can be positioned at multiple locations on the frame 1210; and / or acoustic transducers 1220(I) and 1220(J) that can be positioned on the corresponding neckband 1205.

[0099] In some embodiments, one or more of acoustic transducers 1220(A) to 1220(J) may be used as an output transducer (e.g., a speaker). For example, acoustic transducers 1220(A) and / or 1220(B) may be earbuds or any other suitable type of earphone or speaker.

[0100] The configuration of each acoustic transducer 1220 of the microphone array may vary. Fig.12 12 is shown as having ten acoustic transducers 1220, but the number of acoustic transducers 1220 can be more or less than ten. In some embodiments, using a greater number of acoustic transducers 1220 can increase the amount of audio information collected and / or improve the sensitivity and accuracy of the audio information. In contrast, using a smaller number of acoustic transducers 1220 can reduce the computing power required for the associated controller 1250 to process the collected audio information. In addition, the position of each acoustic transducer 1220 of the microphone array can vary. For example, the position of the acoustic transducer 1220 can include a defined position on the user, a defined coordinate on the frame 1210, an orientation associated with each acoustic transducer 1220, or some combination thereof.

[0101] The acoustic transducers 1220(A) and 1220(B) can be located on different parts of the user's ear, such as behind the pinna, behind the tragus, and / or in the auricle or ear cavity. Alternatively, in addition to the acoustic transducer 1220 in the ear canal, there can be additional acoustic transducers 1220 on or around the ear. Positioning the acoustic transducers 1220 near the user's ear canal can enable the microphone array to collect information about how sound reaches the ear canal. By positioning at least two of these acoustic transducers 1220 on both sides of the user's head (e.g., as binaural microphones), the augmented reality system 1200 can simulate binaural hearing and capture a 3D stereo sound field around the user's head. In some embodiments, acoustic transducers 1220(A) and 1220(B) may be connected to augmented reality system 1200 via wired connection 1230, while in other embodiments, acoustic transducers 1220(A) and 1220(B) may be connected to augmented reality system 1200 via a wireless connection (e.g., a Bluetooth connection). In still other embodiments, acoustic transducers 1220(A) and 1220(B) may not be used in conjunction with augmented reality system 1200 at all.

[0102] The acoustic transducers 1220 on the frame 1210 can be positioned in a variety of different ways, including along the length of the temples, across the bridge, above or below the display device 1215(A) and the display device 1215(B), or some combination thereof. The acoustic transducers 1220 can also be oriented so that the microphone array can detect sounds in a wide range of directions around the user wearing the augmented reality system 1200. In some embodiments, an optimization process can be performed during the manufacture of the augmented reality system 1200 to determine the relative positioning of the acoustic transducers 1220 in the microphone array.

[0103] In some examples, the augmented reality system 1200 may include or be connected to an external device (e.g., a paired device), such as a neckband 1205. Neckband 1205 generally represents any type or form of paired device. Therefore, the following discussion of neckband 1205 may also be applied to various other paired devices, such as charging boxes, smart watches, smart phones, wristbands, other wearable devices, handheld controllers, tablets, laptops, other external computing devices, etc.

[0104] As shown, the neckband 1205 can be coupled to the eye-mounted device 1202 via one or more connectors. The connectors can be wired or wireless and can include electronic components and / or non-electronic (e.g., structural) components. In some cases, the eye-mounted device 1202 and the neckband 1205 can operate independently without any wired or wireless connection between them. Although Fig.12 Various components of the eye-mounted device 1202 and the neckband 1205 are shown located at example locations on the eye-mounted device 1202 and the neckband 1205, but the components can be located elsewhere on the eye-mounted device 1202 and / or the neckband 1205 and / or distributed differently on the eye-mounted device 1202 and / or the neckband 1205. In some embodiments, components of the eye-mounted device 1202 and the neckband 1205 can be located on one or more additional peripheral devices that are paired with the eye-mounted device 1202, the neckband 1205, or some combination thereof.

[0105] Pairing an external device (e.g., a neckband 1205) with an augmented reality eye-mounted device can enable the eye-mounted device to achieve a pair of eye-mounted form factors while still providing sufficient battery power and computing power for the expanded capabilities. Some or all of the battery power, computing resources, and / or additional features of the augmented reality system 1200 can be provided by the paired device, or shared between the paired device and the eye-mounted device, thereby reducing the weight, thermal distribution, and form factor of the eye-mounted device as a whole, while still retaining the desired functionality. For example, since users can bear a heavier weight load on their shoulders than they can bear on their heads, the neckband 1205 can allow components that would otherwise be included on the eye-mounted device to be included in the neckband 1205. The neckband 1205 can also have a larger surface area through which heat is diffused and dissipated to the surrounding environment. Therefore, the neckband 1205 can allow for greater battery power and computing power than would otherwise be possible on a standalone eye-mounted device. Because the weight carried in the neckband 1205 can be less invasive to the user than the weight carried in the eye-mounted device 1202, the user can tolerate wearing a lighter eye-mounted device and carrying or wearing a paired device for longer periods of time than the user can tolerate wearing a heavy stand-alone eye-mounted device, thereby enabling the user to more fully integrate the artificial reality environment into their daily activities.

[0106] The neckband 1205 may be communicatively coupled to the eye-mounted device 1202 and / or communicatively coupled to other devices. These other devices may provide certain functionality (e.g., tracking, positioning, depth mapping, processing, storage, etc.) to the augmented reality system 1200. Fig.12 In an embodiment of the present invention, the neckband 1205 may include two acoustic transducers (e.g., 1220 (I) and 1220 (J)), which are part of the microphone array (or potentially form their own microphone sub-array). The neckband 1205 may also include a controller 1225 and a power supply 1235.

[0107] The acoustic transducers 1220(I) and 1220(J) of the neckband 1205 may be configured to detect sound and convert the detected sound into an electronic format (analog or digital). Fig.12 In an embodiment of the present invention, the acoustic transducers 1220(I) and 1220(J) can be located on the neckband 1205, thereby increasing the distance between the neckband acoustic transducers 1220(I) and 1220(J) and other acoustic transducers 1220 located on the eye-mounted device 1202. In some cases, increasing the distance between the acoustic transducers 1220 of the microphone array can improve the accuracy of the beamforming performed by the microphone array. For example, if the acoustic transducers 1220(C) and 1220(D) detect a sound, and the distance between the acoustic transducers 1220(C) and 1220(D) is greater than, for example, the distance between the acoustic transducers 1220(D) and 1220(E), the determined source location of the detected sound can be more accurate than when it is detected by the acoustic transducers 1220(D) and 1220(E).

[0108] The controller 1225 of the neckband 1205 can process information generated by the sensors on the neckband 1205 and / or the augmented reality system 1200. For example, the controller 1225 can process information from the microphone array that describes the sound detected by the microphone array. For each detected sound, the controller 1225 can perform a direction-of-arrival (DOA) estimate to estimate from which direction the detected sound arrives at the microphone array. When the microphone array detects a sound, the controller 1225 can fill the audio data set with this information. In an embodiment where the augmented reality system 1200 includes an inertial measurement unit, the controller 1225 can calculate all inertial calculations and spatial calculations from the IMU located on the eye-mounted device 1202. The connector can transmit information between the augmented reality system 1200 and the neckband 1205, and between the augmented reality system 1200 and the controller 1225. The information can be in the form of optical data, electronic data, wireless data, or any other transmittable data form. Moving the processing of information generated by the augmented reality system 1200 to the neck strap 1205 can reduce the weight and heat of the eye device 1202, making the eye-mounted device more comfortable for the user.

[0109] The power supply 1235 in the neckband 1205 can provide power to the eye-mounted device 1202 and / or the neckband 1205. The power supply 1235 can include, but is not limited to, lithium-ion batteries, lithium-polymer batteries, primary lithium batteries, alkaline batteries, or any other form of power storage device. In some cases, the power supply 1235 can be a wired power supply. Including the power supply 1235 on the neckband 1205 instead of the eye-mounted device 1202 can help better distribute the weight and heat generated by the power supply 1235.

[0110] As mentioned, some artificial reality systems may substantially replace one or more of a user's multiple sensory perceptions of the real world with a virtual experience, rather than blending the artificial reality with the real reality. An example of this type of system is a head-mounted display system that covers most or all of the user's field of view, e.g. Fig.13 13. Virtual reality system 1300 may include a front rigid body 1302 and a band 1304 shaped to fit around a user's head. Virtual reality system 1300 may also include output audio transducers 1306 (A) and 1306 (B). Fig.13 , but the front rigid body 1302 may include one or more electronic components, including one or more electronic displays, one or more inertial measurement units (IMUs), one or more tracking transmitters or detectors, and / or any other suitable device or system for creating an artificial reality experience.

[0111] Artificial reality systems may include various types of visual feedback mechanisms. For example, the display devices in the augmented reality system 1200 and / or the virtual reality system 1300 may include one or more liquid crystal displays (LCDs), one or more light emitting diode (LED) displays, one or more micro LED displays, one or more organic LED (OLED) displays, one or more digital light project (DLP) micro displays, one or more liquid crystal on silicon (LCoS) micro displays, and / or any other suitable type of display screen. These artificial reality systems may include a single display screen for both eyes, or a display screen may be provided for each eye, which may provide additional flexibility for zoom adjustment or correction of the user's refractive error. Some of these artificial reality systems may also include multiple optical subsystems having one or more lenses (e.g., traditional concave or convex lenses, Fresnel lenses, adjustable liquid lenses, etc.), through which the user can view the display screen. These optical subsystems can be used for a variety of purposes, including collimating light (e.g., making an object appear to be at a greater distance than it is physically at), magnifying light (e.g., making an object appear larger than its actual size), and / or delivering light (e.g., delivering light to a viewer's eye). These optical subsystems can be used in a direct-view architecture (e.g., a single lens configuration that directly collimates light but produces so-called pincushion distortion) and / or a non-direct-view architecture (e.g., a multi-lens configuration that produces so-called barrel distortion to eliminate pincushion distortion).

[0112] In addition to or instead of using a display screen, some of the artificial reality systems described herein may include one or more projection systems. For example, each display device in the augmented reality system 1200 and / or the virtual reality system 1300 may include a micro LED projector that projects light into the display device (e.g., using a waveguide), and the display device is, for example, a transparent combination lens that allows ambient light to pass through. The display device can refract the projected light toward the user's pupil, and can enable the user to view both the artificial reality content and the real world at the same time. The display device can use any of a variety of different optical components to achieve this, including waveguide elements (e.g., holographic waveguide elements, planar waveguide elements, diffractive waveguide elements, polarization waveguide elements, and / or reflective waveguide elements), light manipulation surfaces and elements (e.g., diffractive elements and gratings, reflective elements and gratings, and refractive elements and gratings), coupling elements, etc. The artificial reality system can also be configured with an image projection system of any other suitable type or form, such as a retinal projector used in a virtual retinal display.

[0113] The artificial reality systems described herein may also include various types of computer vision components and subsystems. For example, the augmented reality system 1200 and / or the virtual reality system 1300 may include one or more optical sensors, such as a two-dimensional (2D) camera or a 3D camera, a structured light emitter and detector, a time-of-flight depth sensor, a single beam or scanning laser rangefinder, a 3D laser radar (LiDAR) sensor, and / or any other suitable type or form of optical sensor. The artificial reality system may process data from one or more of these sensors to identify the user's location, map the real world, provide the user with context about the real-world surroundings, and / or perform various other functions.

[0114] The artificial reality system described herein may also include one or more input and / or output audio transducers. The output audio transducer may include a voice coil speaker, a ribbon speaker, an electrostatic speaker, a piezoelectric speaker, a bone conduction transducer, a cartilage conduction transducer, an auricle vibration transducer, and / or any other suitable type or form of audio transducer. Similarly, the input audio transducer may include a condenser microphone, a dynamic microphone, a ribbon microphone, and / or any other type or form of input transducer. In some embodiments, a single transducer may be used for both audio input and audio output.

[0115] In some embodiments, the artificial reality systems described herein may also include tactile (i.e., haptic) feedback systems that can be incorporated into headwear, gloves, clothing, handheld controllers, environmental devices (e.g., chairs, floor mats, etc.), and / or any other type of device or system. The tactile feedback system can provide various types of skin feedback (including vibration, thrust, pull, texture, and / or temperature). The tactile feedback system can also provide various types of kinesthetic feedback, such as motion and compliance. Tactile feedback can be implemented using motors, piezoelectric actuators, fluid systems, and / or various other types of feedback mechanisms. The tactile feedback system can be implemented independently of other artificial reality devices, implemented within other artificial reality devices, and / or implemented in combination with other artificial reality devices.

[0116] By providing tactile perception, auditory content, and / or visual content, artificial reality systems can create complete virtual experiences or enhance the user's real-world experience in various contexts and environments. For example, artificial reality systems can assist or expand a user's perception, memory, or cognition in a specific environment. Some systems can enhance the user's interaction with other people in the real world, or can achieve more immersive interaction with other people in the virtual world. Artificial reality systems can also be used for educational purposes (e.g., for teaching or training in schools, hospitals, government organizations, military organizations, enterprises, etc.), entertainment purposes (e.g., for playing video games, listening to music, watching video content, etc.) and / or for accessibility purposes (e.g., as hearing aids, visual aids, etc.). The embodiments disclosed herein can implement or enhance the user's artificial reality experience in one or more of these contexts and environments, and / or in other contexts and environments.

[0117] The process parameters and step sequences described and / or shown herein are provided as examples only and may vary as desired. For example, although the steps shown and / or described herein may be shown or discussed in a particular order, the steps do not necessarily need to be performed in the order shown or discussed. The various exemplary methods described and / or shown herein may also omit one or more of the steps described or shown herein, or include additional steps in addition to those disclosed steps.

[0118] The foregoing description has been provided to enable others skilled in the art to best utilize the various aspects of the exemplary embodiments disclosed herein. This exemplary description is not intended to be exhaustive or limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the present disclosure. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. In determining the scope of the present disclosure, reference should be made to the appended claims and their equivalents.

[0119] Unless otherwise noted, the terms "connected to" and "coupled to" (and their derivatives) as used in the specification and claims should be understood to allow both direct and indirect connections (i.e., via other elements or components). In addition, the terms "a" or "an" as used in the specification and claims should be understood to mean "at least one of..." Finally, for ease of use, the terms "including" and "having" (and their derivatives) as used in the specification and claims are interchangeable with the word "comprising" and have the same meaning as the word "comprising".

[0120] It will be understood that when an element (e.g., a layer or region) is referred to as being formed on, deposited on, or disposed “on” or “over” another element, the one element may be directly on at least a portion of the other element, or one or more intervening elements may also be present. Conversely, when an element is referred to as being “directly on” or “directly over” another element, the one element may be on at least a portion of the other element without intervening elements.

[0121] As used herein, the term "substantially" in relation to a given parameter, performance or condition may refer to and include the extent to which a person of ordinary skill in the art would understand that the given parameter, performance or condition has a minor degree of variation, such as within acceptable manufacturing tolerances. As an example, depending on the particular parameter, performance or condition being substantially satisfied, these parameters, performance or conditions may be at least about 90% satisfied, at least about 95% satisfied, or even at least about 99% satisfied.

[0122] As used herein, in certain embodiments, the term "about" in reference to a particular value or range of values ​​may refer to and include the stated value and all values ​​within 10% of the stated value. Thus, as an example, in certain embodiments, referring to a value of "50" as "about 50" may include values ​​equal to 50±5, i.e., values ​​in the range of 45 to 55.

[0123] Although the transition phrase "comprising" may be used to disclose various features, elements, or steps of a particular embodiment, it should be understood that alternative embodiments are implicitly included that include embodiments that may be described using the transition phrases "consisting of" or "consisting essentially of. Thus, for example, implicitly included alternative embodiments of a polymer film that comprises or includes polyethylene naphthalate include embodiments in which the polymer film consists essentially of polyethylene naphthalate and embodiments in which the polymer film consists of polyethylene naphthalate.

Claims

1. A lighting assembly, comprising: a light source; and a reflective polarizer that overlaps with the light source, wherein a portion of the light incident on the reflective polarizer does not pass through the reflective polarizer and is reflected back to the light source.

2. The lighting assembly according to claim 1, further comprising an optical element disposed between the light source and the reflective polarizer, wherein: the optical element is coupled to the light source; and the optical element is covered by the reflective polarizer.

3. The lighting assembly according to claim 1, wherein: the light reflected back to the light source is reabsorbed by the light source; and in response to the reabsorbed light, the light source re-emits light to the reflective polarizer.

4. The lighting assembly of claim 1, wherein: The light source includes at least one of a light-emitting diode (LED) light source, a micro-LED light source, an organic light-emitting diode (OLED) light source, a micro-OLED light source, a liquid crystal on silicon (LCoS) light source, or an fLCoS light source.

5. The lighting assembly of claim 1, wherein: The reflective polarizer includes a thin polymer reflective polarizer.

6. The lighting assembly of claim 5, wherein: The thin polymer reflective polarizer includes a polymer birefringent multilayer structure.

7. The lighting assembly according to claim 6, wherein: the birefringent multilayer structure includes a plurality of alternating first layers and a plurality of second layers; The plurality of first layers each include an in-plane refractive index n x (1) and n y (1) isotropic polymer film, and each of the plurality of second layers comprises an in-plane refractive index n x (2) and n y (2) anisotropic polymer film; n1x = n1y and n2x < n2y or n2y < n2x; and n1x < 1.8, n1y < 1.8, │n1x - n1y│ < 0.1, n2y > 1.5, and │n2x - n2y│ > 0.

05.

8. The lighting assembly of claim 7, wherein: │n2x - n2y│ > 0.

1.

9. The lighting assembly of claim 6, wherein: The birefringent multilayer structure has an average reflectivity of less than about 1% in the range of 400 nm to 700 nm along the pass direction and an average reflectivity of at least about 90% in the range of 400 nm to 700 nm along the blocking direction.

10. The lighting assembly of claim 1, wherein: The total thickness of the reflective polarizer is less than 0.5h, where h is the height of the semiconductor component of the LED.

11. The lighting assembly of claim 1, wherein: The spectral bandwidth of the reflective polarizer is at least 1.1 times as large as the spectral bandwidth of the LED, but not greater than 2 times the bandwidth, and the central wavelength emitted by the LED matches the central wavelength of the reflective polarizer.

12. The lighting assembly of claim 1, wherein: The reflective polarizer reflects more than 90% of one of the s-polarized light or p-polarized light while transmitting at least 85% of the other of the s-polarized light or the p-polarized light.

13. The lighting assembly of claim 1 further comprising a sacrificial layer disposed directly on the reflective polarizer, wherein: The sacrificial layer includes a portion having a surface energy of less than about 38 dynes / cm.

14. The lighting assembly according to claim 1, wherein: the light source includes a group of 2 to 6 LEDs; and each LED emits at least one of red spectral light, green spectral light, or blue spectral light.

15. The lighting assembly of claim 14, wherein: The spectral bandwidth of the reflective polarizer is broadband and at least covers the sum of the LED groups within the visible spectrum of about 400 nm to 720 nm.

16. The lighting assembly of claim 14, wherein: The spectral bandwidth of the reflective polarizer is at least 1 times as large as the spectral bandwidth of the LED, but not greater than 2 times the bandwidth.

17. The lighting assembly according to claim 1, further comprising at least one removable layer that overlaps with the surface of the reflective polarizer.

18. A reflective polarizer, the reflective polarizer comprising: a first major surface; a second major surface; a first reflective polarizer region; as well as a second reflective polarizer region, in: the first reflective polarizer region being adjacent the first major surface; the second reflective polarizer region is adjacent to the first reflective polarizer region; the first reflective polarizer region preferentially reflects at least one of red, green, or blue light from the first major surface at an incident angle of about 30 degrees to about 60 degrees from normal in air; and The second reflective polarizer region reflects at least one of red, green, or blue light at an incident angle of about 0 to 20 degrees from normal in air.

19. A method comprising: forming a reflective polarizer by forming an alternating stack of at least one first polymer layer having a first birefringence and at least one second polymer layer having a second birefringence that is different from the first birefringence; as well as An adhesive layer is formed on at least one surface of the reflective polarizer.

20. The method of claim 19, further comprising: A removable layer is disposed on the adhesive layer.

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