Patent Application
20240142677
The accompanying drawings illustrate a number of 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.
Throughout the drawings, identical reference characters and descriptions indicate similar, but not necessarily identical, elements. While the exemplary embodiments described herein are susceptible to various modifications and alternative forms, specific embodiments have been shown byway of example in the drawings and will be described in detail herein. However, the exemplary embodiments described herein are not intended to be limited to the particular forms disclosed. Rather, the present disclosure covers all modifications, equivalents, and alternatives falling within the scope of the appended claims.
Polymer materials may be incorporated into a variety of different optic and electro-optic systems, including passive and active optics and electroactive devices. Lightweight and conformable, one or more polymer layers may be incorporated into wearable devices such as smart glasses and are attractive candidates for emerging technologies including virtual reality/augmented reality devices where a comfortable, adjustable form factor is desired.
Virtual reality (VR) and augmented reality (AR) eyewear devices or headsets, for instance, may enable users to experience events, such as interactions with people in a computer-generated simulation of a three-dimensional world or viewing data superimposed on a real-world view. By way of example, superimposing information onto a field of view may 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. AR/VR eyewear devices and headsets may be used for a variety of purposes. Governments may use such devices for military training, medical professionals may use such devices to simulate surgery, and engineers may use such devices as design visualization aids.
These and other applications may leverage one or more characteristics of polymer materials, including the refractive index to manipulate light, thermal conductivity to manage heat, and mechanical strength and toughness to provide light-weight structural support. In various applications, optical elements and other components may include polymer thin films that have anisotropic mechanical and/or optical properties. The degree of optical or mechanical anisotropy achievable through conventional thin film manufacturing processes is typically limited, however, and is often exchanged for competing thin film properties such as flatness, toughness and/or film strength. For example, highly anisotropic polymer thin films often exhibit low strength in one or more in-plane direction, which may challenge manufacturability and limit performance.
Polymer thin films exhibiting optical anisotropy, for instance, may be incorporated into a variety of systems and devices, including birefringent gratings, reflective polarizers, optical compensators and optical retarders for systems using polarized light such as liquid crystal displays (LCDs). Birefringent gratings may be used as optical combiners in augmented reality displays, for example, and as input and output couplers for waveguides and fiber optic systems. Reflective polarizers may be used in many display-related applications, particularly in pancake optical systems and for brightness enhancement within display systems that use polarized light. For orthogonally polarized light, pancake lenses may use reflective polarizers with extremely high contrast ratios for transmitted light, reflected light, or both transmitted and reflected light.
Notwithstanding recent developments, it would be advantageous to provide optical quality polymer thin films that may be incorporated into various optical systems including display systems for artificial reality applications. The instant disclosure is thus directed generally to polymer thin films and polymer multilayers having engineered optical and mechanical properties, and more specifically to wavelength band selective (reflective or transmissive) filters, including notched reflective polarizers and notched reflectors formed from such thin films. Such wavelength band selective filters may be referred to as “notched” filters. As used herein, a notched reflective polarizer may be configured to interact with polarized light, whereas a notched reflector may be configured to interact with non-polarized light.
According to particular embodiments, functional notched filters may be configured as notched reflective polarizers that are arranged to selectively reflect polarized light across a relatively narrow band. A relatively narrow band may be characterized by a FWHM of less than approximately 60 nm. An ultra-narrow band may be characterized by a FWHM of less than approximately 30 nm. Such notched filters may include a multilayer stack of engineered polymer thin films. Further example notched filters may include liquid crystals, organic crystals and/or inorganic crystals. Moreover, particularly for AR/VR applications, where comparative broadband reflective polarizers may scatter ambient light that adversely affects display contrast, the notched filters disclosed herein may pass ambient light. Additionally, the presently-disclosed notched reflective polarizers may be configured to transmit complementary polarizations of incident light, while reflecting only a narrowband portion of the spectrum.
According to some embodiments, a notched reflective polarizer (RP) may be configured to partially or totally reflect light having a selected polarization state across a chosen range (i.e., band) of wavelengths. A normalized reflectance may range from approximately 5% to approximately 100%, e.g., 5, 10, 20, 50, 80, 90, 95, or 100%. Light having a non-selected polarization state, or having wavelengths outside of the chosen band, may be substantially unaffected by the notched RP. Reflected light may be s-polarized (transverse electric mode) or p-polarized (transverse magnetic mode).
Whereas various embodiments and examples are described throughout the specification in the context of, and with reference to, a notched (narrow band) reflective polarizer, it will be appreciated that the instant description fully contemplates the complementary embodiments of a notched transmissive polarizer and a notched transflective polarizer, including the design, manufacture, and operation thereof.
In some examples, the reflected bandwidth (FWHM) of a notched filter may range from approximately 0.1 nm to approximately 100 nm, e.g., 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 30, 40, 50, or 100 nm, including ranges between any of the foregoing values.
A narrow band multilayer notched reflective polarizer may be characterized by 0.01<Δnx<0.3, where Δnx=|n1x−n2x|, e.g., Δnx<0.1 to achieve an ultra-narrow (FWHM<30 nm) band, and interlayer matching conditions configured to decrease internal reflections, where Δny<0.05, e.g., Δny=0 and Δnz<0.05, e.g., Δnz=0, where Δny=|n1y−n2y| and Δnz=|n1z−n2z|. According to some embodiments, n1x≠n1y or n2x≠n2y. According to some embodiments, n2x=n2y=n1y, where n1y<n1x. An average refractive index N=(nx+ny+nz)/3 for each first and second polymer layer may be greater than approximately 1.6. For some embodiments, the magnitude of AOI-induced blue shift may be decreased when n1z>1.6, e.g., n1z>1.7 or n1z>1.8, with n1z>n1m or n1z=n1m (m=x or y). A narrow band multilayer notched filter may be configured to reflect display light without appreciably reflecting ambient light.
Advantages associated with the incorporation of a notched RP into augmented reality or virtual reality systems may include decreasing unwanted artifacts resulting from stray light. A notched reflector may be used to mitigate obscuration in AR headsets. Also, a notched reflector may be configured as an accommodation mirror for use in AR headsets.
A notched RP may be incorporated into augmented reality or virtual reality systems to decrease the source(s) of stray light, which may otherwise decrease display contrast. Example optical display systems may include folded optics, such as pancake lenses, Fresnel lenses, diffractive lenses, and refractive lenses. Stray light may be sourced by the ambient environment, for instance, and may be caused by reflections from the system's optical components or even reflections from a body part of the user of the system. Further light sources may include lasers or light emitting diodes, such as uLEDs and OLEDs. In some cases, a notched filter may operate on un-polarized or linearly polarized light. In some cases, a notched reflective polarizer may operate on circularly polarized or elliptically polarized light. A notched reflective polarizer may decrease the bandwidth of light that can be reflected, which may decrease the intensity of the stray light.
In some cases, a notched reflector may be used in AR systems to reduce obscuration. It may be undesirable, for instance, for people viewing an AR system during its use to see the full reflected spectrum that is intended only for the user. With a notched reflector, the total intensity of reflected light may be decreased. Further, according to some embodiments, when both the light source bandwidth and the notched reflector bandwidth are small, the reflector may be essentially “invisible” to an outside viewer.
According to further embodiments, a notched reflector may be made into an accommodation mirror for an AR display system. An accommodation mirror may be mounted in the line-of-sight of the system's user. In contrast to a full spectrum reflector (e.g., mirror) that blocks the user's view, a notched reflector may be configured to reflect only a narrow bandwidth of light, which allows the user to view the outside world. In particular embodiments, a notched reflector as disclosed herein may be oriented at an angle (e.g., 45°) with respect to a user, such as in the example of a 450 beam-splitter, which may be desirably unnoticed by an outside viewer.
As disclosed further herein, a notched filter, such as a notched reflective polarizer or notched reflector may include a multilayer stack of polymer thin films. The optical, thermal, and mechanical response of a polymer thin film may be determined by its chemical composition, the chemical structure of the polymer repeat unit, its density and extent of crystallinity, as well as the alignment of the crystals and/or polymer chains throughout the polymer matrix. Among these factors, the crystal or polymer chain alignment may dominate. In crystalline or semi-crystalline polymer thin films, an optical, thermal, or mechanical property or condition may be correlated to the degree or extent of crystal orientation, whereas the degree or extent of chain entanglement may create comparable optical, thermal, or mechanical properties in thin films that include an amorphous polymer.
As will be appreciated, for a reflective polarizer having a multilayer architecture, the path difference between reflected rays will vary as a function of the angle of incidence (AOI) of the illuminating light. As the AOI increases, the constructive interference spectral band will exhibit a shift toward lower wavelengths, i.e., a blueshift effect. By way of example, a narrowband polarizer reflecting red wavelengths at normal incidence may reflect green wavelengths for an AOI of 45°. In some embodiments, a notched reflective polarizer may be configured to minimize this blueshift effect and reflect incident light over a narrow band independent of the angle of incidence. This may be particularly advantageous for applications with large AOI requirements, such as wide field-of-view AR/VR optical displays.
An applied stress may be used to form a preferred alignment of crystals or polymer chains within a polymer thin film and induce a corresponding modification of the optical, thermal, and/or mechanical properties along different directions of the film. As disclosed further herein, during processing where a polymer thin film is stretched to induce a preferred alignment of crystals/polymer chains and an attendant modification of the refractive index/birefringence, thermal, and mechanical properties. Applicants have shown that an extrusion method can decrease the propensity for polymer chain entanglement within the extruded thin film.
An extruded polymer thin film or polymer multilayer may be stretched using single or multiple stretching events. Some stretching processes may include two or more successive stretching events. For instance, orthogonal consecutive stretching may be used to develop structural fingerprints, such as smaller lamellar thicknesses and higher degrees of polymer chain orientation at draw ratios less than the draw ratios used to achieve similar structural fingerprints via comparative single stretching (SS) or parallel consecutive stretching (PCS) techniques. Orthogonal consecutive stretching may include stretching a polymer thin film along a first in-plane axis, and then subsequently stretching the polymer thin film along a second in-plane axis that is orthogonal to the first in-plane axis.
Stretching may include a single act of stretching or plural, successive stretching events, such as along different in-plane directions of a polymer thin film. The act of stretching may be velocity limited or strain rate limited. In some embodiments, a polymer thin film may be stretched at a variable or constant velocity. In some embodiments, the polymer thin film may be stretched using a variable strain rate or a constant strain rate (e.g., 0.5/sec, 1/sec, 5/sec, or 10/sec, including ranges between any of the foregoing values). By way of example, the strain rate may decrease throughout an act of stretching and/or amongst different stretching events from an initial strain rate (e.g., 5/sec) to a final strain rate (e.g., 0.5/sec).
The crystalline content within the polymer thin film may increase during an act of stretching. Alternatively, in some embodiments, stretching may alter the orientation of crystals within a polymer thin film without substantially changing the crystalline content.
Polymer thin films may be oriented either uniaxially or biaxially and stacked as a multilayer to form a notched reflective polarizer or a notched reflector. An anisotropic polymer thin film may be formed using a thin film orientation system configured to heat and stretch a polymer thin film in at least one in-plane direction in one or more distinct regions thereof. In some embodiments, a thin film orientation system may be configured to stretch a polymer thin film, i.e., a crystallizable polymer thin film, along only one in-plane direction. For instance, a thin film orientation system may be configured to apply an in-plane stress to a polymer thin film along the x-direction while allowing the thin film to relax along an orthogonal in-plane direction (e.g., along the y-direction). As used herein, the relaxation of a polymer thin film may, in certain examples, accompany the absence of an applied stress along a relaxation direction.
According to some embodiments, within an example orientation system, a polymer thin film may be heated and stretched transversely to a direction of film travel through the system. In such embodiments, a polymer thin film may be held along opposing edges by plural movable clips slidably disposed along a diverging track system such that the polymer thin film is stretched in a transverse direction (TD) as it moves along a machine direction (MD) through heating and deformation zones of the thin film orientation system. 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 enabled, for example, using a roll-to-roll manufacturing platform.
In various examples, the extent of relaxation perpendicular to the stretch direction may be approximately equal to the square root of the stretch ratio in the stretch direction. In some embodiments, the extent of relaxation may be substantially constant throughout the stretching process(es). In further embodiments, the extent of relaxation may decrease, with greater relaxation associated with the beginning of a stretch step and lesser relaxation associated with the end of a stretch step.
Following deformation of the polymer thin film, a thermal setting can be applied to the film. The thermal setting temperature can be less than, equal to, or greater than an orientation temperature but above a glass transition temperature of the polymer. The thermal setting can be at a constant strain or a variable strain. The thermal setting may be followed by cooling of the polymer thin film. The act of cooling may include allowing the polymer thin film to cool naturally, at a set cooling rate, or by quenching, such as by purging with a low temperature gas, which may thermally stabilize the polymer thin film.
The presently disclosed polymer thin films may be characterized as optical quality polymer thin films and may form, or be incorporated into, an optical element such as a reflective polarizer or an anti-reflective coating. Optical elements may be used in various display devices, such as virtual reality (VR) and augmented reality (AR) glasses and headsets. The efficiency of these and other optical elements may depend on the degree of optical clarity, birefringence, thermal conductivity, and/or mechanical response.
As used herein, the terms “polymer thin film” and “polymer layer” may be used interchangeably. Furthermore, reference to a “polymer thin film” or a “polymer layer” may include reference to a “multilayer polymer thin film” unless the context clearly indicates otherwise.
In accordance with various embodiments, an optical element includes a notched reflective polarizer (RP). In various embodiments, the reflective polarizer may include a stack of alternating isotropic and anisotropic polymer layers arranged in an alternating ABAB . . . architecture. In further embodiments, an optical element includes a notched reflector. A notched reflector may include alternating isotropic polymer layers.
As used herein, an “isotropic” layer may be characterized by equivalent or substantially equivalent refractive indices. For instance, a polymer layer may have refractive indices nx, ny, nz, where nx and ny are in-plane values, and for an isotropic polymer layer, nx=ny=nz. In a further example, an isotropic polymer layer may have refractive indices that differ by no more than a specified value, D, e.g., |nx−ny|<D, |nx−nz|<D, and |ny−nz|<D, where D may be 0.1, 0.05, 0.02, or 0.01. Typically, the refractive index of a medium decreases with an increase in the wavelength of light traversing the medium. Herein, refractive index values may be defined in terms of reference wavelength, such as 460 nm, 540 nm, 589 nm, or 630 nm. According to further embodiments, in lieu of a particular reference wavelength, refractive index values may be defined with reference to the visible spectrum, e.g., approximately 400 nm to approximately 700 nm.
In particular embodiments, the layers within the stack defining a notched filter may be co-extruded in a single-step process that decreases manufacturing complexity and, relative to comparative processes, obviates the creation of orange peel defects and the undesired realization of reflectivity ripple along the block axis.
An example method may include extruding alternating first and second polymer layers to form a notched filter stack. The method may further include applying an in-plane stress to the multilayer polymer thin film.
Optical properties of the RP multilayer may be tuned by applying an in-plane stress to the multilayer that induces an alignment of crystallites within the thin films and an attendant modification of refractive index and birefringence. For AR/VR applications, for example, the RP multilayer may be laminated over a transparent substrate, such as a varifocal lens.
According to various embodiments, the performance of a notched reflective polarizer may be determined by one or more of (i) the number of polymer layers in the multilayer stack, (ii) the intralayer refractive index and/or birefringence, (iii) the interlayer refractive index and/or birefringence, and (iv) the thickness and thickness profile of the polymer layers.
The following will provide, with reference to
An example notched reflective polarizer architecture is shown schematically in
The second polymer thin films 102 may have a thickness d2 and may include a crystalline or semi-crystalline optically anisotropic polymer, where n2x<n2y=n2z, for example, and may include a second polymer composition. In certain embodiments, the second polymer thin films 102 may be characterized by n2y>1.4, and |n2x−n2y>0.1, e.g., n2y>1.7, and |n2x−n2y|>0.2. In particular embodiments, a high contrast ratio may be achieved where the refractive indices for adjacent layers (e.g., first and second thin films) are equal or substantially equal along a common direction, e.g., n1x=n2x.
According to illustrative embodiments, the first polymer thin films 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 mono-ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, cyclohexane dimethanol, polyethylene glycol, di-hydrogenated organic compounds and the like, as well as combinations and derivatives, including isomers and co-polymers thereof.
The second polymer thin films may include polyethylene naphthalate, polyethylene terephthalate, polyethylene isophthalate, polybutylene naphthalate, polybutylene terephthalate, polyoxymethylene, as well as aliphatic or semi-aromatic polyamides. In some cases, the second polymer thin films may further include one or more oligomers as identified above. The molecular weight of the oligomer may be less than approximately 50% of the molecular weight of the polymer, e.g., less than approximately 30%, less than approximately 10%, less than approximately 5%, or less than approximately 1% of the molecular weight of the polymer.
As shown in the illustrated embodiment of
In an example embodiment, the thickness d1 of first polymer thin films 101 may exhibit a minimum value proximate to each outermost layer of the multilayer stack, and the thickness d1 may increase as a function of position with increasing distance from the outermost layers. A first polymer thin film 101 located proximate to the middle of the multilayer stack may have a maximum thickness, for example. The thickness d2 of second polymer thin films 102 may have a reciprocal relationship. That is, the thickness d2 of second polymer thin films 102 may exhibit a maximum value proximate to each outermost layer of the multilayer stack, and the thickness d2 may decrease as a function of position with increasing distance from the outermost layers. A second polymer thin film 102 located proximate to the middle of the multilayer stack may have a minimum thickness, for example. This thickness relationship amongst the first and second polymer thin films is shown schematically in
Turning to
In
As will be appreciated, although example notched filters are described herein with reference to an alternating pair of polymer layers (e.g., an ABAB . . . configuration of refractive index values along a chosen direction), a greater number of distinct polymer layers and further example stacking sequences may be used. Alternate stacking sequences may include ABCBCA . . . or ABCABC . . . , for example, although further stacking sequences are contemplated.
Referring to
By way of example, and referring still to
During a second stretching step, the polymer thin film may be stretched along a second axis perpendicular to the first axis. The draw ratio during the second stretching step may be at least approximately 1.2, e.g., approximately 1.5, approximately 2, approximately 5, approximately 8, or more, including ranges between any of the foregoing values. In some embodiments, the draw ratio during the first stretching step may be less than the draw ratio during the second stretching step. By way of example, a draw ratio during the first stretching step may be less than approximately 3, or approximately 2, including ranges between any of the foregoing values. Following the second stretching step, the polymer thin film may be heated to increase its crystalline content.
Referring still to
During a first stretching process, an inter-clip spacing 450 within clip array 410 may increase, while an inter-clip spacing 445 within clip array 420 may be fixed. A tensile stress may be applied to the polymer thin film 405 along the machine direction while the polymer thin film is unstressed along the transverse direction, thus forming a uniaxially stretched polymer thin film 440. During a second and subsequent stretching process, an inter-clip spacing 455 within clip array 420 may increase, while an inter-clip spacing 460 within clip array 410 may be fixed. Thus, a tensile stress may be applied to the polymer thin film 440 along the transverse direction while the polymer thin film is unstressed along the machine direction, thus forming a processed polymer thin film 465.
According to further embodiments, a simultaneous biaxial stretch may be performed using the orientation system shown in
A single stage thin film orientation system for forming an optically anisotropic polymer thin film is shown schematically in
Polymer thin film 505 may include a single polymer layer or multiple (e.g., alternating) layers of first and second polymers, such as a multilayer ABAB . . . structure. Alternately, polymer thin film 505 may include a composite architecture having a crystallizable polymer thin film and a high Poisson's ratio polymer thin film directly overlying the crystallizable polymer thin film (not separately shown). In some embodiments, a polymer thin film composite may include a high Poisson's ratio polymer thin film reversibly laminated to, or printed on, a single crystallizable polymer thin film or a multilayer polymer thin film.
During operation, proximate to input zone 530, clips 524, 526 may be affixed to respective edge portions of polymer thin film 505, where adjacent clips located on a given track 525, 527 may be disposed at an inter-clip spacing 550, 555. For simplicity, in the illustrated view, the inter-clip spacing 550 along the first track 525 within input zone 530 may be equivalent or substantially equivalent to the inter-clip spacing 555 along the second track 527 within input zone 530. As will be appreciated, in alternate embodiments, within input zone 530, the inter-clip spacing 550 along the first track 525 may be different than the inter-clip spacing 555 along the second track 527.
In addition to input zone 530 and output zone 547, system 500 may include one or more additional zones 535, 540, 545, etc., where each of: (i) the translation rate of the polymer thin film 505, (ii) the shape of first and second tracks 525, 527, (iii) the spacing between first and second tracks 525, 527, (iv) the inter-clip spacing 550, 552, 554, 555, 557, 559, and (v) the local temperature of the polymer thin film 505, etc. may be independently controlled.
In an example process, as it is guided through system 500 by clips 524, 526, polymer thin film 505 may be heated to a selected temperature within each of zones 530, 535, 540, 545, 547. Fewer or a greater number of thermally controlled zones may be used. As illustrated, within zone 535, first and second tracks 525, 527 may diverge along a transverse direction such that polymer thin film 505 may be stretched in the transverse direction while being heated, for example, to a temperature greater than its glass transition temperature (Tg) but less than the onset of melting.
Referring still to
A temperature of the polymer thin film may be controlled within each heating zone. Within stretching zone 535, for example, a temperature of the polymer thin film 505 may be constant or independently controlled within sub-zones 565, 570, for example. In some embodiments, the temperature of the polymer thin film 505 may be decreased as the stretched polymer thin film 505 enters zone 540. Rapidly decreasing the temperature (i.e., thermal quenching) following the act of stretching within zone 535 may enhance the conformability of the polymer thin film 505. In some embodiments, the polymer thin film 505 may be thermally stabilized, where the temperature of the polymer thin film 505 may be controlled within each of the post-stretch zones 540, 545, 547. In some embodiments, a polymer thin film may be heated within one or more post-stretch zones. Heating following an act of stretching, i.e., heat setting, may induce further crystallization of the polymer and may thermally stabilize the thin film and improve its polarization performance and conformability. A thermally-stabilized polymer thin film may be characterized by low machine direction shrinkage. For example, shrinkage along the machine direction of a heat set polymer thin film that is heated to a temperature greater the glass transition temperature of its highest Tg component (e.g., Tg+20° C. or Tg+30° C.) may be less than approximately 20%, e.g., less than 20, 10, 5, or 3%, including ranges between any of the foregoing values. A temperature of the polymer thin film may be controlled by forced thermal convection or by radiation, for example, IR radiation, or a combination thereof.
Downstream of stretching zone 535, according to some embodiments, a transverse distance between first track 525 and second track 527 may remain constant or, as illustrated, initially decrease (e.g., within zone 540 and zone 545) prior to assuming a constant separation distance (e.g., within output zone 547). In a related vein, the inter-clip spacing downstream of stretching zone 535 may increase or decrease relative to inter-clip spacing 552 along first track 525 and inter-clip spacing 557 along second track 527. For example, inter-clip spacing 555 along first track 525 within output zone 547 may be less than inter-clip spacing 552 within stretching zone 535, and inter-clip spacing 559 along second track 527 within output zone 547 may be less than inter-clip spacing 557 within stretching zone 535. According to some embodiments, the spacing between the clips may be controlled by modifying the local velocity of the clips on a linear stepper motor line, or by using an attachment and variable clip spacing mechanism connecting the clips to the corresponding track.
To facilitate cross-stretch relaxation while stretching in the TD direction, the inter-clip spacings 552, 557 within stretching zone 535 may be decreased by at least approximately 10% (e.g., 10%, 20%, 30%, 40%, or 50% or more) relative to respective inter-clip spacings 550, 555 within input zone 530. The relaxation profile may be constant or variable, i.e., as a function of position, across stretching zone 535. According to some embodiments, a maximum TD draw ratio within stretching zone 535 be at least approximately 2 and less than approximately 4. The stretched and oriented polymer thin film 515 may be removed from system 500 and stretched in a further stretching step, such as via length orientation with relaxation as shown in
Referring to
In an example process, proximate to input zone 630, first and second clips 624, 626 may be affixed to edge portions of polymer thin film 605, where adjacent clips located on a given track 625, 627 may be disposed at an initial inter-clip spacing 650, 655, which may be substantially constant or variable along both tracks within input zone 630. Within input zone 630 a distance along the transverse direction between first track 625 and second track 627 may be constant or substantially constant.
System 600 may additionally include one or more zones 635, 640, etc. The dynamics of system 600 allow independent control over: (i) the translation rate of the polymer thin film 605, (ii) the shape of first and second tracks 625, 627, (iii) the spacing between first and second tracks 625, 627 along the transverse direction, (iv) the inter-clip spacing 650, 655 within input zone 630 as well as downstream of the input zone (e.g., inter-clip spacings 652, 654, 657, 659), and (v) the local temperature of the polymer thin film, etc.
In an example process, as it is guided through system 600 by clips 624, 626, polymer thin film 605 may be heated to a selected temperature within each of zones 630, 635, 640, 645. A temperature greater than the glass transition temperature of a component of the polymer thin film 605 may be used during deformation (i.e., within zone 635), whereas a lesser temperature, an equivalent temperature, or a greater temperature may be used within each of one or more downstream zones.
As in the previous embodiment, the temperature of the polymer thin film 605 within stretching zone 635 may be locally controlled. According to some embodiments, the temperature of the polymer thin film 605 may be maintained at a constant or substantially constant value during the act of stretching. According to further embodiments, the temperature of the polymer thin film 605 may be incrementally increased within stretching zone 635. That is, the temperature of the polymer thin film 605 may be increased within stretching zone 635 as it advances along the machine direction. By way of example, the temperature of the polymer thin film 605 within stretching zone 635 may be locally controlled within each of heating zones a, b, and c.
The temperature profile may be continuous, discontinuous, or combinations thereof. As illustrated in
Referring still to
Within stretching zone 635, the inner-clip spacings 652, 657 may increase linearly such that the primary mode of deformation may be at constant velocity. For example, a strain rate of the polymer thin film may decrease along the machine direction. In further embodiments, the polymer thin film 605 may be stretched at a constant strain-rate where the inter-clip spacing may increase exponentially.
In certain examples, a progressively decreasing strain rate may be implemented with thin film orientation system 600 to generate a high refractive index polymer thin film. For instance, within stretching zone 635 an inter-clip spacing may be configured such that a distance between each successive pair of clips 624, 626 increases along the machine direction. The inter-clip spacing between each successive pair of clips may be independently controlled to achieve a desired strain rate along the machine direction.
In response to the tensile stress applied along the machine direction, system 600 is configured to inhibit the generation of stresses and an attendant realignment of crystals along the machine direction. As illustrated, within zone 635, first and second tracks 625, 627 may converge along a transverse direction such that polymer thin film 605 may relax in the transverse direction while being stretched in the machine direction. In some embodiments, a compressive force may be applied in the transverse direction. Using a single stretching step or multiple stretching steps, polymer thin film 605 may be stretched by a factor of at least approximately 1.2, (e.g., 1.2, 1.5, 2, 4, 5, 6, 7, 8, 9, 10, 20, 40, 100, or more, including ranges between any of the foregoing values).
Within stretching zone 635, an angle of inclination of first and second tracks 625, 627 (i.e., with respect to the machine direction) may be constant or variable. In particular examples, the inclination angle within stretching zone 635 may decrease along the machine direction. That is, according to certain embodiments, the inclination angle within heating zone a may be greater than the inclination angle within heating zone b, and the inclination angle within heating zone b may be greater than the inclination angle within heating zone c. Such a configuration may be used to provide a progressive decrease in the relaxation rate (along the transverse direction) within the stretching zone 635 as the polymer thin film advances through system 600.
In some embodiments, the temperature of the polymer thin film 605 may be decreased as the stretched polymer thin film 605 exits zone 635. In some embodiments, the polymer thin film 605 may be thermally stabilized, where the temperature of the polymer thin film 605 may be controlled within each of the post-deformation zones 640, 645. A temperature of the polymer thin film may be controlled by forced thermal convection or by radiation, for example, IR radiation, or a combination thereof.
Downstream of deformation zone 635, the inter-clip spacing may increase or remain substantially constant relative to inter-clip spacing 652 along first track 625 and inter-clip spacing 657 along second track 627. For example, inter-clip spacing 655 along first track 625 within output zone 645 may be substantially equal to the inter-clip spacing 652 as the clips exit zone 635, and inter-clip spacing 659 along second track 627 within output zone 645 may be substantially equal to the inter-clip spacing 657 as the clips exit zone 635. Following the act of stretching, polymer thin film 605 may be annealed, for example, within one or more downstream zones 640, 645.
The strain impact of the thin film orientation system 600 is shown schematically by unit segments 660, 665, which respectively illustrate pre- and post-deformation dimensions for a selected area of polymer thin film 605. In the illustrated embodiment, polymer thin film 605 has a pre-stretch width (e.g., along the transverse direction) and a pre-stretch length (e.g., along the machine direction). As will be appreciated, a post-stretch width may be less than the pre-stretch width and a post-stretch length may be greater than the pre-stretch length.
In some embodiments, a roll-to-roll system may be integrated with a thin film orientation system, such as thin film orientation system 500 or thin film orientation system 600, to manipulate a polymer thin film. In further embodiments, as illustrated herein with reference
An example roll-to-roll polymer thin film orientation system is depicted in
While controlling the temperature of the polymer thin film, rollers 705, 715 may be engaged and the polymer thin film may be stretched. For instance, first roller 705 may rotate at a first rate and second roller 715 may rotate at a second rate greater than the first rate to stretch the polymer thin film along a machine direction therebetween. Within a deformation zone between rollers, system 700 may be configured to locally control the temperature and the strain rate of the polymer thin film. In some examples, as the polymer thin film advances from roller 705 to roller 715, a temperature of the polymer thin film may increase, and a strain rate of the polymer thin film may decrease. Downstream of roller 715, the polymer thin film may then be cooled while maintaining the applied stress. System 700 may be used to form a uniaxially oriented polymer thin film. Additional rollers may be added to system 700 to control the conveyance and take-up of the polymer thin film.
Example processes may be integrated with a real-time feedback loop that is configured to assess one or more attributes of the organic crystal thin film and accordingly adjust one or more process variables. Resultant organic solid structures may be incorporated into optical elements such as AR/VR headsets and other devices, e.g., waveguides, prisms, Fresnel lenses, and the like.
Referring now to
Referring to
Turning to
As will be appreciated with reference to
Referring to
Example multilayer notched reflective polarizer architectures are shown in
Applicants have developed a number of approaches for manufacturing high average refractive index (N>1.6) polymer layers having a small in-plane birefringence. In some embodiments, a high refractive index atom may be incorporated into the polymer backbone or polymer side chain. Example high refractive index atoms include N, O, S, Cl, and Br. Such a polymer material may be oriented uniaxially or biaxially through a suitable stretching process.
According to further embodiments, high average refractive index polymer materials may include a high refractive index (e.g., n>2) organic additive, such as particles, needles, or nanoscale crystals. Such a modified polymer material may be oriented uniaxially or biaxially through a suitable stretching process.
According to still further embodiments, in a multilayer architecture, one of the polymer layers may be formed from or include a liquid crystal, organic crystal, or liquid crystal polymer. The liquid crystal, organic crystal, or liquid crystal polymer may be characterized by nz>nx and nz>ny.
Referring to
Referring to
Referring to
The multilayer reflective polarizer architecture shown in
The multilayer reflective polarizer architecture shown in
The influence of the angle of incidence (AOI) on the blue shift of reflected light for an optically isotropic material (nx=ny=nz=1.60) is shown in
Referring to
In some embodiments, a multilayer notched filter exhibiting low band shift may be configured with alternating layers of anisotropic (n1x>n1y) and isotropic (n2x=n2y) polymer materials. Less phase shift may be attributed to a higher average refractive index in the multilayer, such as when the refractive indices of the isotropic layers are matched to the extraordinary refractive index of the anisotropic layers (i.e., n2x=n2y=n1x).
The influence of the angle of incidence (AOI) on the blue shift of reflected light for optically anisotropic multilayer structures is shown in
Referring to
With reference initially to the reflective polarizer of
Turning to
A notch filter that is immune to the unwanted leakage due to blue shift effects may be formed by combining the structure of
Referring to
According to further embodiments, the molecules shown in
Referring to
The design and optical performance of exemplary multilayer structures, including architectures having an apodized or graduated thickness profile, are shown in
In an example multilayer notched reflective polarizer, the thickness of each individual layer may be engineered to enhance performance, such as across a specified spectral band. Whereas each layer in a comparative multilayer may have an equivalent optical thickness (e.g., λ/4), in some embodiments, the thickness of each layer may be independently chosen and/or determined using an analytical model. Layer-by-layer and modeled asynchronous approaches are illustrated schematically in
Referring to
With reference to
As illustrated, the layer pairs may arranged such that a total thickness of successive layer pairs changes by less than approximately 20% (e.g., less than 5, 10, 15, or 20%) within a first region of the multilayer and a total thickness of neighboring layer pairs changes by at least approximately 40% (e.g., 40, 45, 50, or 55%) within a second region of the multilayer adjacent to the first region. Thus, the multilayer of
Referring to
Referring to
Referring to
As disclosed herein, an optical element includes a polymer multilayer defining a notched reflective polarizer (RP). The reflective polarizer stack may include an alternating ABAB . . . architecture of amorphous, optically isotropic polymer layers and semicrystalline, optically anisotropic polymer layers. Along a block mode of the reflective polarizer, an in-plane refractive index of the anisotropic polymer layers may be greater than an in-plane refractive index of the isotropic polymer layers. On the other hand, along a transmissive (pass) mode orthogonal to the block mode, in-plane refractive indices of the anisotropic and isotropic polymer layers may be substantially equal.
Example 1: A notched filter including a multilayer having alternating first and second polymer layers, the first polymer layers each including a polymer thin film having in-plane refractive indices n1x and n1y, and the second polymer layers each including a polymer thin film having in-plane refractive indices n2x and n2y, where a thickness of each successive first polymer layer and a thickness of each correspondingly successive second polymer layer change asynchronously throughout the multilayer.
Example 2: The notched filter of Example 1, where the first polymer layers each include an isotropic polymer thin film and the second polymer layers each include an anisotropic polymer thin film.
Example 3: The notched filter of any of Examples 1 and 2, where |n1x−n1y|<0.1, n2y>1.4, and |n2x−n2y|>0.01.
Example 4: The notched filter of any of Examples 1-3, where n2y>1.7 and |n2x−n2y|>0.01.
Example 5: The notched filter of any of Examples 1-4, where the multilayer is configured to reflect a band of incident light with a relative intensity of less than approximately 90%.
Example 6: The notched filter of any of Examples 1-4, where the multilayer is configured to reflect a band of incident light with a relative intensity of approximately 100%.
Example 7: The notched filter of any of Examples 1-6, where the multilayer is configured to reflect a band of incident light with a reflected bandwidth of less than approximately 100 nm.
Example 8: The notched filter of any of Examples 1-6, where the multilayer is configured to transmit a band of incident light with a transmitted bandwidth of less than approximately 100 nm.
Example 9: A notched filter including a multilayer having alternating first and second polymer layers, the first polymer layers each including a polymer thin film having in-plane refractive indices n1x and n1y, and the second polymer layers each including a polymer thin film having in-plane refractive indices n2x and n2y, where a thickness difference between neighboring first and second polymer layers is less than approximately 20% within a first region of the multilayer, and a thickness difference between neighboring first and second polymer layers is at least approximately 50% within a second region of the multilayer proximate to the first region.
Example 10: The notched filter of Example 9, where the first polymer layers each include an isotropic polymer thin film and the second polymer layers each include an anisotropic polymer thin film.
Example 11: The notched filter of any of Examples 9 and 10, where |n1x−n1y|<0.1, n2y>1.4 and |n2x−n2y|>0.01.
Example 12: The notched filter of any of Examples 9-11, where n2y>1.7 and |n2x−n2y|>0.01.
Example 13: The notched filter of any of Examples 9-12, where the multilayer is configured to reflect at least one band of incident light with a relative intensity of less than approximately 90%.
Example 14: The notched filter of any of Examples 9-13, where the multilayer is configured to reflect at least one band of incident light with a reflected bandwidth of less than approximately 100 nm.
Example 15: The notched filter of any of Examples 9-13, where the multilayer is configured to transmit at least one band of incident light with a transmitted bandwidth of less than approximately 100 nm.
Example 16: A notched filter includes a multilayer having alternating first and second polymer layers, the first polymer layers each including a polymer thin film having in-plane refractive indices n1x and n1y, and the second polymer layers each including a polymer thin film having in-plane refractive indices n2x and n2y, where 0.01<|n1x−n2x|<0.3, 0.01<|n1y−n2y|<0.3, and an average refractive index for each first and second polymer layer is greater than approximately 1.6.
Example 17: The notched filter of Example 16, where n1x≠n1y or n2x≠n2y.
Example 18: The notched filter of Example 16, where |n1x−n2x|<0.1 and |n1y−n2y|<0.1.
Example 19: The notched filter of Example 16, where n1x=n1y and n2x=n2y.
Example 20: The notched filter of Example 16, where the average refractive index for each first and second polymer layer is greater than approximately 1.7.
Example 21: A notched filter including a multilayer having alternating first and second polymer layers forming layer pairs, the first polymer layers each including a polymer thin film having in-plane refractive indices n1x and n1y, and the second polymer layers each including a polymer thin film having in-plane refractive indices n2x and n2y, where a total thickness of successive layer pairs changes by less than approximately 20% within a first region of the multilayer and a total thickness of neighboring layer pairs changes by at least approximately 50% within a second region of the multilayer adjacent to the first region.
Example 22: The notched filter of Example 21, where, within a selected layer pair, a thickness of the first polymer layer is substantially equal to a thickness of the second polymer layer.
Example 23: A method including heating a segment of a crystallizable polymer thin film to a first temperature, applying a stress to the crystallizable polymer thin film in an amount effective to induce a positive strain within the heated segment, and removing the applied stress while continuing to heat the segment of the polymer thin film to form an oriented crystalline polymer article.
Example 24: The method of Example 23, including (a) attaching a clip array to opposing edges of the crystallizable polymer thin film, the clip array including a plurality of first clips slidably disposed on a first track located proximate to a first edge of the crystallizable polymer thin film and a plurality of second clips slidably disposed on a second track located proximate to a second edge of the crystallizable polymer thin film, (b) applying a stress to the crystallizable polymer thin film along a machine direction by increasing an inter-clip spacing amongst the first clips and simultaneously increasing an inter-clip spacing amongst the second clips, and (c) decreasing a distance between the first clips and the second clips to allow the crystallizable polymer thin film to relax in a transverse direction while applying the stress.
Example 25: A uniaxially-oriented polymer thin film having an average glass transition temperature (Tg), where the polymer thin film contracts by less than approximately 20% along a machine direction when heated to a temperature of at least approximately Tg+20° C.
Example 26: An optical element including a lens and a notched filter disposed over a surface of the lens, where the notched filter includes a multilayer thin film and is configured to reflect only selected bands of visible light.
Example 27: The optical element of Example 26, where the selected bands of visible light are red, green, and blue spectral components.
Example 28: A multilayer thin film including alternating first and second layers, where the first layers each include an anisotropic polymer thin film having in-plane refractive indices n1x and n1y and the second layers each include an isotropic polymer thin film having in-plane refractive indices n2x and n2y, with n1x>n1y and n2x=n2y=n1x.
Example 29: A multilayer thin film including alternating first and second layers, wherein the first layers each include an anisotropic polymer thin film having in-plane refractive indices n1x and n1y, with nx1>n1y and n1x-n1y<0.3, and the second layers each include an isotropic polymer thin film having in-plane refractive indices n2x and n2y, with n2x=n2y=n1y.
Embodiments of the present disclosure may include or be implemented in conjunction with various types of artificial-reality systems. Artificial reality is a form of reality that has been adjusted in some manner before presentation to a user, which may include, for example, a virtual reality, an augmented reality, a mixed reality, a hybrid reality, or some combination and/or derivative thereof. Artificial-reality content may include completely computer-generated content or computer-generated content combined with captured (e.g., real-world) content. The artificial-reality content may include video, audio, haptic feedback, or some combination thereof, any of which may be presented in a single channel or in multiple channels (such as stereo video that produces a three-dimensional (3D) effect to the viewer). Additionally, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof, that are used to, for example, create content in an artificial reality and/or are otherwise used in (e.g., to perform activities in) an artificial reality.
Artificial-reality systems may be implemented in a variety of different form factors and configurations. Some artificial-reality systems may be designed to work without near-eye displays (NEDs). Other artificial-reality systems may include an NED that also provides visibility into the real world (such as, e.g., augmented-reality system 4700 in
Turning to
In some embodiments, augmented-reality system 4700 may include one or more sensors, such as sensor 4740. Sensor 4740 may generate measurement signals in response to motion of augmented-reality system 4700 and may be located on substantially any portion of frame 4710. Sensor 4740 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, augmented-reality system 4700 may or may not include sensor 4740 or may include more than one sensor. In embodiments in which sensor 4740 includes an IMU, the IMU may generate calibration data based on measurement signals from sensor 4740. Examples of sensor 4740 may include, without limitation, accelerometers, gyroscopes, magnetometers, other suitable types of sensors that detect motion, sensors used for error correction of the IMU, or some combination thereof.
In some examples, augmented-reality system 4700 may also include a microphone array with a plurality of acoustic transducers 4720(A)-4720(J), referred to collectively as acoustic transducers 4720. Acoustic transducers 4720 may represent transducers that detect air pressure variations induced by sound waves. Each acoustic transducer 4720 may be configured to detect sound and convert the detected sound into an electronic format (e.g., an analog or digital format). The microphone array in
In some embodiments, one or more of acoustic transducers 4720(A)-(J) may be used as output transducers (e.g., speakers). For example, acoustic transducers 4720(A) and/or 4720(B) may be earbuds or any other suitable type of headphone or speaker.
The configuration of acoustic transducers 4720 of the microphone array may vary. While augmented-reality system 4700 is shown in
Acoustic transducers 4720(A) and 4720(B) may be positioned on different parts of the user's ear, such as behind the pinna, behind the tragus, and/or within the auricle or fossa. Or, there may be additional acoustic transducers 4720 on or surrounding the ear in addition to acoustic transducers 4720 inside the ear canal. Having an acoustic transducer 4720 positioned next to an ear canal of a user may enable the microphone array to collect information on how sounds arrive at the ear canal. By positioning at least two of acoustic transducers 4720 on either side of a user's head (e.g., as binaural microphones), augmented-reality device 4700 may simulate binaural hearing and capture a 3D stereo sound field around about a user's head. In some embodiments, acoustic transducers 4720(A) and 4720(B) may be connected to augmented-reality system 4700 via a wired connection 4730, and in other embodiments acoustic transducers 4720(A) and 4720(B) may be connected to augmented-reality system 4700 via a wireless connection (e.g., a BLUETOOTH connection). In still other embodiments, acoustic transducers 4720(A) and 4720(B) may not be used at all in conjunction with augmented-reality system 4700.
Acoustic transducers 4720 on frame 4710 may be positioned in a variety of different ways, including along the length of the temples, across the bridge, above or below display devices 4715(A) and 4715(B), or some combination thereof. Acoustic transducers 4720 may also be oriented such that the microphone array is able to detect sounds in a wide range of directions surrounding the user wearing the augmented-reality system 4700. In some embodiments, an optimization process may be performed during manufacturing of augmented-reality system 4700 to determine relative positioning of each acoustic transducer 4720 in the microphone array.
In some examples, augmented-reality system 4700 may include or be connected to an external device (e.g., a paired device), such as neckband 4705. Neckband 4705 generally represents any type or form of paired device. Thus, the following discussion of neckband 4705 may also apply to various other paired devices, such as charging cases, smart watches, smart phones, wrist bands, other wearable devices, hand-held controllers, tablet computers, laptop computers, other external compute devices, etc.
As shown, neckband 4705 may be coupled to eyewear device 4702 via one or more connectors. The connectors may be wired or wireless and may include electrical and/or non-electrical (e.g., structural) components. In some cases, eyewear device 4702 and neckband 4705 may operate independently without any wired or wireless connection between them. While
Pairing external devices, such as neckband 4705, with augmented-reality eyewear devices may enable the eyewear devices to achieve the form factor of a pair of glasses while still providing sufficient battery and computation power for expanded capabilities. Some or all of the battery power, computational resources, and/or additional features of augmented-reality system 4700 may be provided by a paired device or shared between a paired device and an eyewear device, thus reducing the weight, heat profile, and form factor of the eyewear device overall while still retaining desired functionality. For example, neckband 4705 may allow components that would otherwise be included on an eyewear device to be included in neckband 4705 since users may tolerate a heavier weight load on their shoulders than they would tolerate on their heads. Neckband 4705 may also have a larger surface area over which to diffuse and disperse heat to the ambient environment. Thus, neckband 4705 may allow for greater battery and computation capacity than might otherwise have been possible on a stand-alone eyewear device. Since weight carried in neckband 4705 may be less invasive to a user than weight carried in eyewear device 4702, a user may tolerate wearing a lighter eyewear device and carrying or wearing the paired device for greater lengths of time than a user would tolerate wearing a heavy standalone eyewear device, thereby enabling users to more fully incorporate artificial-reality environments into their day-to-day activities.
Neckband 4705 may be communicatively coupled with eyewear device 4702 and/or to other devices. These other devices may provide certain functions (e.g., tracking, localizing, depth mapping, processing, storage, etc.) to augmented-reality system 4700. In the embodiment of
Acoustic transducers 4720(I) and 4720(J) of neckband 4705 may be configured to detect sound and convert the detected sound into an electronic format (analog or digital). In the embodiment of
Controller 4725 of neckband 4705 may process information generated by the sensors on neckband 4705 and/or augmented-reality system 4700. For example, controller 4725 may process information from the microphone array that describes sounds detected by the microphone array. For each detected sound, controller 4725 may perform a direction-of-arrival (DOA) estimation to estimate a direction from which the detected sound arrived at the microphone array. As the microphone array detects sounds, controller 4725 may populate an audio data set with the information. In embodiments in which augmented-reality system 4700 includes an inertial measurement unit, controller 4725 may compute all inertial and spatial calculations from the IMU located on eyewear device 4702. A connector may convey information between augmented-reality system 4700 and neckband 4705 and between augmented-reality system 4700 and controller 4725. The information may be in the form of optical data, electrical data, wireless data, or any other transmittable data form. Moving the processing of information generated by augmented-reality system 4700 to neckband 4705 may reduce weight and heat in eyewear device 4702, making it more comfortable to the user.
Power source 4735 in neckband 4705 may provide power to eyewear device 4702 and/or to neckband 4705. Power source 4735 may include, without limitation, lithium ion batteries, lithium-polymer batteries, primary lithium batteries, alkaline batteries, or any other form of power storage. In some cases, power source 4735 may be a wired power source. Including power source 4735 on neckband 4705 instead of on eyewear device 4702 may help better distribute the weight and heat generated by power source 4735.
As noted, some artificial-reality systems may, instead of blending an artificial reality with actual reality, substantially replace one or more of a user's sensory perceptions of the real world with a virtual experience. One example of this type of system is a head-worn display system, such as virtual-reality system 4800 in
Artificial-reality systems may include a variety of types of visual feedback mechanisms. For example, display devices in augmented-reality system 4700 and/or virtual-reality system 4800 may include one or more liquid crystal displays (LCDs), light emitting diode (LED) displays, microLED displays, organic LED (OLED) displays, digital light project (DLP) micro-displays, 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 may provide a display screen for each eye, which may allow for additional flexibility for varifocal adjustments or for correcting a user's refractive error. Some of these artificial-reality systems may also include optical subsystems having one or more lenses (e.g., conventional concave or convex lenses, Fresnel lenses, adjustable liquid lenses, etc.) through which a user may view a display screen. These optical subsystems may serve a variety of purposes, including to collimate (e.g., make an object appear at a greater distance than its physical distance), to magnify (e.g., make an object appear larger than its actual size), and/or to relay (to, e.g., the viewer's eyes) light. These optical subsystems may be used in a non-pupil-forming architecture (such as a single lens configuration that directly collimates light but results in so-called pincushion distortion) and/or a pupil-forming architecture (such as a multi-lens configuration that produces so-called barrel distortion to nullify pincushion distortion).
In addition to or instead of using display screens, some of the artificial-reality systems described herein may include one or more projection systems. For example, display devices in augmented-reality system 4700 and/or virtual-reality system 4800 may include microLED projectors that project light (using, e.g., a waveguide) into display devices, such as clear combiner lenses that allow ambient light to pass through. The display devices may refract the projected light toward a user's pupil and may enable a user to simultaneously view both artificial-reality content and the real world. The display devices may accomplish this using any of a variety of different optical components, including waveguide components (e.g., holographic, planar, diffractive, polarized, and/or reflective waveguide elements), light-manipulation surfaces and elements (such as diffractive, reflective, and refractive elements and gratings), coupling elements, etc. Artificial-reality systems may also be configured with any other suitable type or form of image projection system, such as retinal projectors used in virtual retina displays.
The artificial-reality systems described herein may also include various types of computer vision components and subsystems. For example, augmented-reality system 4700 and/or virtual-reality system 4800 may include one or more optical sensors, such as two-dimensional (2D) or 3D cameras, structured light transmitters and detectors, time-of-flight depth sensors, single-beam or sweeping laser rangefinders, 3D LiDAR sensors, and/or any other suitable type or form of optical sensor. An artificial-reality system may process data from one or more of these sensors to identify a location of a user, to map the real world, to provide a user with context about real-world surroundings, and/or to perform a variety of other functions.
The artificial-reality systems described herein may also include one or more input and/or output audio transducers. Output audio transducers may include voice coil speakers, ribbon speakers, electrostatic speakers, piezoelectric speakers, bone conduction transducers, cartilage conduction transducers, tragus-vibration transducers, and/or any other suitable type or form of audio transducer. Similarly, input audio transducers may include condenser microphones, dynamic microphones, ribbon microphones, 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.
In some embodiments, the artificial-reality systems described herein may also include tactile (i.e., haptic) feedback systems, which may be incorporated into headwear, gloves, body suits, handheld controllers, environmental devices (e.g., chairs, floormats, etc.), and/or any other type of device or system. Haptic feedback systems may provide various types of cutaneous feedback, including vibration, force, traction, texture, and/or temperature. Haptic feedback systems may also provide various types of kinesthetic feedback, such as motion and compliance. Haptic feedback may be implemented using motors, piezoelectric actuators, fluidic systems, and/or a variety of other types of feedback mechanisms. Haptic feedback systems may be implemented independent of other artificial-reality devices, within other artificial-reality devices, and/or in conjunction with other artificial-reality devices.
By providing haptic sensations, audible content, and/or visual content, artificial-reality systems may create an entire virtual experience or enhance a user's real-world experience in a variety of contexts and environments. For instance, artificial-reality systems may assist or extend a user's perception, memory, or cognition within a particular environment. Some systems may enhance a user's interactions with other people in the real world or may enable more immersive interactions with other people in a virtual world. Artificial-reality systems may also be used for educational purposes (e.g., for teaching or training in schools, hospitals, government organizations, military organizations, business 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 may enable or enhance a user's artificial-reality experience in one or more of these contexts and environments and/or in other contexts and environments.
The process parameters and sequence of the steps described and/or illustrated herein are given by way of example only and can be varied as desired. For example, while the steps illustrated and/or described herein may be shown or discussed in a particular order, these steps do not necessarily need to be performed in the order illustrated or discussed. The various exemplary methods described and/or illustrated herein may also omit one or more of the steps described or illustrated herein or include additional steps in addition to those disclosed.
The preceding description has been provided to enable others skilled in the art to best utilize various aspects of the exemplary embodiments disclosed herein. This exemplary description is not intended to be exhaustive or to be 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 illustrative and not restrictive. Reference should be made to the appended claims and their equivalents in determining the scope of the present disclosure.
Unless otherwise noted, the terms “connected to” and “coupled to” (and their derivatives), as used in the specification and claims, are to be construed as permitting both direct and indirect (i.e., via other elements or components) connection. In addition, the terms “a” or “an,” as used in the specification and claims, are to be construed as meaning “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 and have the same meaning as the word “comprising.”
It will be understood that when an element such as a layer or a region is referred to as being formed on, deposited on, or disposed “on” or “over” another element, it may be located directly on at least a portion of the other element, or one or more intervening elements may also be present. In contrast, when an element is referred to as being “directly on” or “directly over” another element, it may be located on at least a portion of the other element, with no intervening elements present.
As used herein, the term “substantially” in reference to a given parameter, property, or condition may mean and include to a degree that one of ordinary skill in the art would understand that the given parameter, property, or condition is met with a small degree of variance, such as within acceptable manufacturing tolerances. By way of example, depending on the particular parameter, property, or condition that is substantially met, the parameter, property, or condition may be at least approximately 90% met, at least approximately 95% met, or even at least approximately 99% met.
As used herein, the term “approximately” in reference to a particular numeric value or range of values may, in certain embodiments, mean and include the stated value as well as all values within 10% of the stated value. Thus, by way of example, reference to the numeric value “50” as “approximately 50” may, in certain embodiments, include values equal to 50±5, i.e., values within the range 45 to 55.
While various features, elements or steps of particular embodiments may be disclosed using the transitional phrase “comprising,” it is to be understood that alternative embodiments, including those that may be described using the transitional phrases “consisting of” or “consisting essentially of,” are implied. Thus, for example, implied alternative embodiments to a polymer thin film that comprises or includes polyethylene naphthalate include embodiments where a polymer thin film consists essentially of polyethylene naphthalate and embodiments where a polymer thin film consists of polyethylene naphthalate.
This application claims the benefit of priority under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 63/381,446, filed Oct. 28, 2022, the contents of which are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63381446 | Oct 2022 | US |
