Abstract: A display assembly includes a light source, a spatial light modulator (SLM) and a grating. The light source is configured to emit illumination light, the SLM is configured to receive the illumination light and reflect at least a portion of the illumination light. The grating is positioned to redirect the illumination light output from the light source toward the SLM, receive at least a portion of the reflected light from the SLM, redirect first light having a first polarization toward the light source, and transmit through the grating second light having a second polarization that is orthogonal to the first polarization. Also disclosed are operations performed by the display assembly.

Abstract: Methods and systems for image sensing are provided. In one example, an apparatus comprises a semiconductor substrate comprising a light incident surface to receive light, a first pinned photodiode, and a second pinned photodiode, the first pinned photodiode and the second pinned photodiode forming a stack structure in the semiconductor substrate along an axis perpendicular to the light incident surface, the stack structure enabling the first pinned photodiode and the second pinned photodiode to, respectively, convert a first component of the light and a second component of the light to first charge and second charge. The apparatus further comprises one or more capacitors formed in the semiconductor substrate and configured to generate a first voltage and a second voltage based on, respectively, the first charge and the second charge.

Abstract: The disclosed transparent circuit board may include a transparent substrate, a first conductive trace coupled to the transparent substrate, and an electrical component having a bottom surface facing the transparent substrate and a top surface facing away from the transparent substrate. The bottom surface may include a first electrical contact coupled to the first conductive trace, and the top surface may include a second electrical contact. The transparent circuit board may also include a second conductive trace electrically connected to the second electrical contact and a transparent encapsulation layer coupled to the transparent substrate and encapsulating the electrical component. Various other ophthalmic devices, systems, and methods are also disclosed.

Abstract: Disclosed herein includes a system, a method, and a device for interacting with displayed items. A contact point can be established with a surface of a contact panel and the contact panel can be operated in a navigation mode during which a selection element, for selecting one or more items of a user interface (UI) in a display of a second device, is maintained at a determined location in the display. The UI can be moved in the display relative to the selection element as the selection element is maintained at the determined location, by moving the contact point on the surface of the contact panel in the navigation mode. At least one item of the UI that is moved within a selection threshold of the selection element can be selected by removing the contact point with the contact panel.

Abstract: An apparatus for creating and tuning haptic feedback is provided. The apparatus includes (A) a brace with first and second portions, (B) a vibrotactile actuator, coupled to the first portion of the brace, configured to apply haptic stimulations to a user, and (C) a linear actuator, coupled to the second portion of the brace, configured to (i) obtain a signal generated based on information about the user's body at a target location of the user and (ii) adjust a tension of the brace according to the signal. In some embodiments, the apparatus also includes one or more sensors configured to generate the information about the user's body at the target location. Furthermore, a controller may be configured to: (i) generate the signal based on the information about the user's body at the target location generated by the one or more sensors and (ii) provide the signal to the linear actuator.

Abstract: Disclosed herein includes a system, a method, and a device for improving computation efficiency of a neural network. In one aspect, adder circuitry is configured to add input data from processing of the neural network and a first number of bits of accumulated data for the neural network to generate summation data. In one aspect, according to a carry value of the adding from the adder circuitry, a multiplexer is configured to select between i) a second number of bits of the accumulated data and ii) incremented data comprising the second number of bits of the accumulated data incremented by a predetermined value. The summation data appended with the selected one of the second number of bits of the accumulated data or the incremented data may form appended data.

Abstract: In general, this disclosure describes scalable, partitionable encryption engines. The partitionable encryption engines of this disclosure yield power savings, such as by controlling operation of partitioned sub-datapaths at reduced clock rates. An apparatus includes an interface configured to receive a block of encrypted data for decryption, and a decryption engine in communication with the interface. The decryption engine includes a plurality of decryption sub-datapaths, where each respective decryption sub-datapath has no data interdependency with any other decryption sub-datapath of the plurality of decryption sub-datapaths. The decryption engine is configured to selectively enable one or more decryption sub-datapaths of the plurality of decryption sub-datapaths to decrypt the block of encrypted data to form a decrypted block of data.

Abstract: In one embodiment, a computing system may receive a video including a sequence of frames. The computing system may access a three-dimensional mask that specifies pixel-sampling locations, the three-dimensional mask having a first dimension and a second dimension corresponding to a spatial domain and a third dimension corresponding to a temporal domain. Blue noise property may be present in the pixel-sampling locations that are associated with each of a plurality of two-dimensional spatial slices of the three-dimensional mask in the spatial domain and the pixel-sampling locations that are associated with each of a plurality of one-dimensional temporal slices of the three-dimensional mask in the temporal domain. The computing system may generate a sample of the video by sampling the sequence of frames using the three-dimensional mask.

Abstract: A lens assembly includes a first optical element and a second optical element. The first optical element includes a flat partially reflective layer. The second optical element includes a curved reflective polarizer layer.

Abstract: An animatronic device includes a mechanical eyeball configured to rotate about a first rotational axis and a second rotational axis that intersect at a fixed center point. A controller is configured to generate eye movement instructions that cause the animatronic device to rotate the mechanical eyeball about at least one of the first rotational axis and the second rotational axis. The eye movement instructions are generated based on an eye tracking system used to track movement of an eye of a user. The controller maps the tracked eye movement to movement of the mechanical eyeball and generates eye movement instructions based on the mapping.

Abstract: Techniques for adjusting an optical element using an actuator assembly. The optical element is adjusted by translating the optical element along a linear axis of motion or by applying force upon a surface of the optical element. The optical element can be a liquid lens that is shaped by the application of force upon a surface of the lens. The actuator assembly includes a plurality of lead screws and a mechanical linkage that intercouples the lead screws and that is configured to simultaneously rotate the plurality of lead screws. The actuator assembly further includes a displacement element configured to act upon the optical element, through translational motion of the displacement element in response to rotation of the lead screws. Multiple optical elements can be adjusted simultaneously using respective displacement elements coupled to the lead screws.

Abstract: A display device includes a projector and a display that has a first surface and a second surface. The projector is configured to project image light toward the display. The display is configured to output diffused image light from the first surface and to transmit ambient light from the second surface to the first surface. The display device also includes an optical assembly that has a substrate with substantially uniform thickness. The optical assembly is configured to receive the diffused image light and transmit a portion of the diffused image light output from the first surface of the display at a first optical power. The optical assembly is also configured to receive the ambient light and transmit a portion of the ambient light through the optical assembly at a second optical power that is less than the first optical power.

Abstract: The invention is directed towards enhanced systems and methods for employing a pulsed photon (or EM energy) source, such as but not limited to a laser, to electrically couple, bond, and/or affix the electrical contacts of a semiconductor device to the electrical contacts of another semiconductor devices. Full or partial rows of LEDs are electrically coupled, bonded, and/or affixed to a backplane of a display device. The LEDs may be ?LEDs. The pulsed photon source is employed to irradiate the LEDs with scanning photon pulses. The EM radiation is absorbed by either the surfaces, bulk, substrate, the electrical contacts of the LED, and/or electrical contacts of the backplane to generate thermal energy that induces the bonding between the electrical contacts of the LEDs' electrical contacts and backplane's electrical contacts. The temporal and spatial profiles of the photon pulses, as well as a pulsing frequency and a scanning frequency of the photon source, are selected to control for adverse thermal effects.

Abstract: Ghost images can interfere with eye tracking in a system that uses folded optics, such as is an artificial-reality display. Optical elements, such as waveplates and/or polarizers, can be used to attenuate or eliminate light causing the ghost images.

Abstract: Example devices include a fluidic device, such as a fluidic valve, including a body formed from a rigid body material including a fluidic source, a fluidic drain, and a fluidic gate, each of which may have a fluid connection with a chamber, or a portion thereof. The device may further include a gate transmission element, located within the chamber, that is controllable between at least a first position and a second position using a gate pressure received through the fluidic drain. Adjustment of the position of the gate transmission element may allow control of fluid flow through the device. Other devices, methods, systems, and computer-readable media are also disclosed.

Abstract: An electrostatic zipping actuator includes a primary electrode, a secondary electrode overlying the primary electrode, a dielectric layer located between and abutting at least a portion of the primary electrode and the secondary electrode, and a dielectric fluid disposed at least at a junction between the dielectric layer and one of the electrodes, where an average total thickness of the dielectric layer is less than approximately 10 micrometers.

Abstract: An optical waveguide is provided. The optical waveguide includes a base structure and a plurality of grating structures disposed at the base structure. The grating structures include a plurality of in-coupling grating structures configured to couple a plurality of lights into the optical waveguide. At least one of a grating period or a slant angle of a first in-coupling grating structure is different from at least one of a corresponding grating period or a corresponding slant angle of a second in-coupling grating structure. The grating structures also include a plurality of out-coupling grating structures configured to couple the lights out of the optical waveguide.

Abstract: A flexure guidance system may be provided for controlling movement of an optical subassembly and/or a connected combiner lens. For instance, the flexure guidance system may include a distal end piece, a proximal end piece, and multiple wire flexures that link the distal end piece to the proximal end piece. The linking wire flexures may be spaced to form an interior cavity between the distal end piece and the proximal end piece. This interior cavity may house various electronic components. One or more actuators in the system may move the electronic components according to input signals along different axes of movement provided by the wire flexures. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: A device for providing a 1D line of an image is disclosed. The device includes a wavelength-tunable light source for providing image light having the angular distribution encoded in optical spectrum. The device further includes a thin slab waveguide having an out-coupler in form of a diffraction grating for out-coupling the image light at an angle dependent on wavelength. The image may be formed by scanning a collimated beam propagating in the slab waveguide when using tunable monochromatic light sources, or by forming the 1D singular distribution of brightness at a same time when using a tunable-spectrum light sources. The device may be used in a near-eye display for forming a 2D image in angular domain.

Abstract: Disclosed herein are related to a system and a method of remotely rendering an image. In one approach, a console device generates an image according to a gaze direction of a user of a head mounted display (HMD). In one aspect, the image includes a first area and a second area disposed along an axis, where the second area is located farther away from a foveated area of the image than the first area. In one aspect, the foveated area corresponds to the gaze direction of the user of the HMD. In one aspect, the console device compresses the image according to the axis, where the second area is compressed at a higher level than the first area. In one aspect, the compressed image is transmitted to the HMD. The HMD may decompress the compressed image according to the axis, and render the decompressed image.

Abstract: Aspects of the present disclosure are directed to virtual interaction modes for social and group communication. Additional aspects of the present disclosure are directed to automated controls for connecting a trigger performed in an artificial reality environment to an action on a personal computing device. Further aspects of the present disclosure are directed to providing versions of person virtual objects in an artificial reality environment and contextual breakpoints to switch between them. Yet further aspects of the present disclosure are directed to extending a mouse for artificial reality environment input.

Abstract: In one embodiment, a method includes receiving a request to transfer a handle to an object from a first process to a second process, accessing a first security context of the handle and a second security context of the second process, identifying one or more security policies based on at least one of the first security context and the second security context, determining that the handle is allowed to be transferred to the second process by applying the one or more security policies on the first security context of the handle and the second security context of the second process, and transferring the handle to the second process in response to the request.

Abstract: A telecentric optical element that has a first surface, a second surface, and a layer of optically anisotropic material between the first surface and the second surface. The telecentric optical element is configured to receive light on the first surface, the light having propagated from a location within a predetermined distance range from the first surface of the optical element. The telecentric optical element is also configured to redirect a first portion of the light, having a first polarization, off the first surface of the telecentric optical element in an off-axis direction, and to transmit a second portion of light, having polarization different from the first polarization, to the second surface. An eye-tracking assembly that includes the telecentric optical element and a display device that includes the telecentric optical element are also disclosed.

Abstract: A system for vibration-driven sensing may include a wearable dimensioned to be donned by a user of an artificial reality system. The system may also include a vibration sensor that is incorporated into the wearable and generates an electrical response that corresponds to a vibration detected at the wearable. The system may further include at least one processing device communicatively coupled to the vibration sensor. The processing device may determine, based at least in part on the electrical response generated by the vibration sensor, that the user has made a specific gesture with at least one body part. In response to this determination, the processing device may generate an input command for the artificial reality system based at least in part on the specific gesture made by the user. Various other systems and methods are also disclosed.

Abstract: In one embodiment, a method includes generating a handle that references a checkpoint for a service, sending the handle to the service, wherein the handle is configured to be used by the service to store one or more states of the service in the checkpoint, determining that the service needs to be restarted, restarting the service, accessing the handle for the checkpoint, and sending the handle for the checkpoint to the restarted service, wherein the handle for the checkpoint is configured to be used by the restarted service to restore the one or more states.

Abstract: An optical system includes an optical lens, a polarization volume hologram (PVH) layer arranged over the optical lens, and an IR absorbing structure arranged between the optical lens and the PVH layer. The PVH layer being configured to reflect infrared (IR) light. The IR absorbing structure includes a quarter-wave plate (QWP) arranged between the optical lens and the PVH layer and a linear absorptive polarizer arranged between the QWP and the optical lens. The linear absorptive polarizer is configured to absorb IR light.

Abstract: In one embodiment, a method includes receiving a first frame associated with a first time and one or more second frames of a video having a resolution lower than a target resolution, wherein each second frame is associated with a second time prior to the first time, generating a first feature map for the first frame and one or more second feature maps for the one or more second frames, up-sampling the first feature map and the one or more second feature maps to the target resolution, warping each of the up-sampled second feature maps according to a motion estimation between the associated second time and the first time, and generating a reconstructed frame having the target resolution corresponding to the first frame by using a machine-learning model to process the up-sampled first feature map and the one or more up-sampled and warped second feature maps.

Abstract: A system receives audio data in a frequency range of 20 Hz-20 kHz. The received audio data is encoded by the system into ultrasonic data in frequencies that are greater than 20 kHz, and transmitted into a local area that is proximal to the transmitting device, i.e., within the transmission range of the transmitting device. An ultrasonic communication device that is located in the transmission range of the transmitting device may receive the ultrasonic data. The received ultrasonic data is decoded by the ultrasonic communication system in the receiving device into audio data in a frequency range of 20 Hz-20 kHz, and subsequently presented to a user of the receiving ultrasonic communication device.

Abstract: A polarization volume hologram (PVH) lens includes a PVH layer having a freeform design. The PVH layer includes a first region and a second region having different optical properties.

Abstract: In one embodiment, a method includes receiving, from a client system associated with a first user, a first audio input. The method includes generating multiple transcriptions corresponding to the first audio input based on multiple automatic speech recognition (ASR) engines. Each ASR engine is associated with a respective domain out of multiple domains. The method includes determining, for each transcription, a combination of one or more intents and one or more slots to be associated with the transcription. The method includes selecting, by a meta-speech engine, one or more combinations of intents and slots from the multiple combinations to be associated with the first user input. The method includes generating a response to the first audio input based on the selected combinations and sending, to the client system, instructions for presenting the response to the first audio input.

Abstract: A scanning projector display includes a plurality of light engines coupled to a MEMS scanner. Each light engine includes a light source subassembly for providing a diverging light beam optically coupled to a collimator for collimating the diverging light beam. In operation, the collimated light beams of the plurality of light engines impinge onto the tiltable reflector at different angles of incidence. A controller may be operably coupled to the light source subassembly of each light engine of the plurality of light engines and the MEMS scanner for tilting the tiltable reflector of the MEMS scanner. The controller is configured to energize the light source of each light engine in coordination with tilting the tiltable reflector for displaying the image.

Abstract: A system on a chip (SoC) includes a security processor configured to determine that a first channel ID describing a {source, destination} tuple for a crypto packet matches a second channel ID describing a corresponding {source, destination} tuple for a preceding crypto packet received immediately prior to the crypto packet. The SoC also includes a decryption engine configured to, responsive to the determination that the first channel ID matches the second channel ID: obtain a set of round keys applied to perform an add round key computational stage of a previous decryption datapath used to decrypt a preceding cipher text block obtained from the preceding crypto packet, and to reuse the set of round keys to perform a corresponding add round key computational stage of a current decryption datapath used to decrypt a cipher text block obtained from the crypto packet.

Abstract: The disclosed wearable apparatus may include (1) a device dimensioned to fit about a body part of a user, (2) a tensioning mechanism that harnesses to the device in a manner that is relative to the fit of the device about the body part of the user, and (3) an actuator couples to the tensioning mechanism that, when actuated, causes substantially tangential movement of the tensioning mechanism relative to a surface of the body part to produce substantially orthogonal movement of the device relative to the surface of the body part. Various other methods, systems, and/or computer-readable media are also disclosed.

Abstract: In one embodiment, a method includes, by one or more computing systems, receiving, from a client system, an input in a multi-turn message thread, parsing the input to identify a plurality of hypothesis dialog states associated with the input, generating a plurality of functions corresponding to the plurality of hypothesis dialog states, calculating a plurality of probability scores for the plurality of functions, respectively, based on a prior dialog state associated with the message thread and a current user context, wherein each probability score represents a likelihood that the respective function is associated with an intended dialog state, and storing the plurality of functions if each of the probability scores is below a threshold probability score, wherein the plurality of functions is stored as a hierarchical set of functions that is used as the prior dialog state in response to a next input in the message thread.

Abstract: An optical device for a head-mounted display device includes a first partial reflector and a second partial reflector positioned relative to the first partial reflector so that the second partial reflector receives first light transmitted through the first partial reflector and reflects at least a portion of the first light toward the first partial reflector as second light. At least a portion of the second light is reflected by the first partial reflector as third light, and at least a portion of the third light is transmitted through the second partial reflector. At least one of the first partial reflector or the second partial reflector includes a reflective holographic element.

Abstract: The disclosed high-efficiency motor may include the following: at least two magnets, a rigid structure arranged between the at least two magnets, where the rigid structure has traces configured to act as a moveable coil, and at least two couplings that respectively link the magnets to the rigid structure in a flexible manner. An electrical input signal applied to the moveable coil may cause motive force to be applied the rigid structure according to the input signal, so that the rigid structure moves orthogonally relative to the magnets as driven by the input signal. In this manner, the high-efficiency motor may be incorporated into a system that may reproduce a full-range audio signal. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: A piezoelectric microelectromechanical systems (MEMS) transducer that can operate as a microphone (e.g., contact microphone) or a speaker is presented herein. The piezoelectric MEMS transducer includes a substrate, a proof mass and folded displacement sensing structures. Each folded displacement sensing structure comprises a continuous beam, a first piezoelectric stress sensor coupled to a first portion of the continuous beam, and a second piezoelectric stress sensor coupled to a second portion of the continuous beam. The first portion of the continuous beam is coupled to a respective portion of the proof mass, and the second portion of the continuous beam is coupled to a respective portion of the substrate. The first and second portions of the continuous beam come together at an acute angle. The first and second piezoelectric stress sensors output stress information responsive to a stress induced in the continuous beam by displacement of the proof mass.

Abstract: In one embodiment, a method includes displaying, through a head-mounted display (HMD), virtual objects to a user wearing the HMD. The method then accesses a boundary definition that corresponds to a boundary within a physical space surrounding the user and generates a plurality of spatial points based on depth measurements of physical objects within the physical space. Based on the spatial points, a location at which a physical object is likely to exist is determined. The method determines whether the location of the physical object is inside the boundary definition and, in response to this determination, issues an alert to the user.

Abstract: Methods and apparatus for enabling a user or third-party to select or adjust parameters of one or more statistical models used to generate a musculoskeletal representation. The method comprises providing as input to the statistical model(s), a plurality of neuromuscular signals recorded by a plurality of neuromuscular sensors during performance of at least one gesture by a user, wherein the at least one gesture is performed by the user while wearing a wearable device having the plurality of neuromuscular sensors arranged thereon, rendering at least one visual representation based on an output of the statistical model(s), and receiving user or third-party input to adjust parameters of the statistical model(s) based on the rendered at least one visual representation, the user input including a selection of a particular statistical model of the statistical model(s) and/or an adjustment of parameters associated with the particular statistical model.

Abstract: In one example, an apparatus is provided. The apparatus comprises an image sensor configured to generate a first raw output to represent a first intensity of incident light based on a first relationship, and to generate a second raw output to represent a second intensity of incident light based on a second relationship. The apparatus further comprises a post processor configured to: generate a first post-processed output based on the first raw output and based on the first relationship such that the first post-processed output is linearly related to the first intensity based on a third relationship, and to generate a second post-processed output based on the second raw output and based on the second relationship such that the second post-processed output is linearly related to the second intensity based on the third relationship.

Abstract: Disclosed herein are techniques for managing the thermal resistance and the planarity of a display package. According to certain embodiments, a device includes a display package having a molding compound; a plurality of light emitting diode (LED) dies arranged on a top surface of the display package, wherein each LED die of the plurality of LED dies includes a plurality of LEDs; a backplane die embedded within the molding compound of the display package, wherein the backplane die is electrically coupled to each LED die of the plurality of LED dies; and at least one spacer structure embedded within the molding compound of the display package. The backplane die and the at least one spacer structure together provide mechanical support and planar alignment for the plurality of LED dies arranged on the top surface of the display package. The at least one spacer structure has a first thermal conductivity, and the molding compound has a second thermal conductivity lower than the first thermal conductivity.

Abstract: Systems and methods for transitioning a call between two devices are disclosed herein. An origin device for the call is determined based on a first position of an ultra-wideband (UWB) device. A destination device for the call is then determined based on a second position of the UWB device. The UWB device sends transition commands to both the origin device and the destination device, each transition command including an identifier of the other device. Using the identifier of the origin device, the destination device connects to the call the origin device is currently participating in. When the origin device detects that the destination device has connected to the call, the origin device disconnects from the call.

Abstract: The disclosed wearable devices may include a body shaped and sized to be worn against a user's skin, a flexible vibrotactile actuator positioned on or in the body, and a tunable stiffness material adjacent to the flexible haptic actuator. The flexible vibrotactile actuator may be in a location to transmit a haptic sensation to the user's skin when the body is worn by the user. The tunable stiffness material may have an adjustable stiffness such that adjustment of the stiffness of the tunable stiffness material alters a haptic sensation induced by the flexible haptic actuator against the user's skin. Various other related methods, systems, and devices are also disclosed.

Abstract: A rhythm-based video game (“game”) is disclosed. In the game, a player slashes blocks representing musical beats using a pair of energy blades resembling a lightsaber. A gaming console renders multiple digital objects, e.g., digital blocks, digital mines and digital obstacles, that are approaching a player in a virtual space. The gaming console also renders a digital representation of an instrument, e.g., a lightsaber (“digital saber”), using which the player slashes, cuts or otherwise interacts with the digital blocks to cause a digital collision between the digital saber and the digital blocks. The player can score by slashing the digital blocks, not hitting the digital mines and avoiding the digital obstacles. The game presents the player with a stream of approaching digital objects in synchronization with music, e.g., a song's beats, being played in the game. The pace at which the digital blocks approach the player increases with the beats.

Abstract: A micro-light emitting diode (micro-LED) includes a current aperture to confine the current in a localized region such that the carrier recombination mostly occurs in the localized region to emit photons, thereby reducing the surface recombination and improving the quantum efficiency. The current confinement and localization are achieved using a localized breakthrough of a barrier layer by a localized contact, lightly p-doped active layers to suppress lateral transport of the carriers to the surface region, selective ion implantation, etching, or oxidation of a semiconductor layer, or any combination thereof.

Abstract: An audio system for a wearable device dynamically updates acoustic transfer functions. The audio system is configured to estimate a direction of arrival (DoA) of each sound source detected by a microphone array relative to a position of the wearable device within a local area. The audio system may track the movement of each sound source. The audio system may form a beam in the direction of each sound source. The audio system may identify and classify each sound source based on the sound source properties. Based on the DoA estimates, the movement tracking, and the beamforming, the audio system generates or updates the acoustic transfer functions for the sound sources.

Abstract: Embodiments of the present disclosure support a head-mounted display (HMD) wirelessly coupled to a console. The HMD includes a positional tracking system, a beam controller and a transceiver. The positional tracking system tracks position of the HMD and generates positional information describing the tracked position of the HMD. The transceiver communicates with a console via a wireless channel, in accordance with communication instructions, the communication instructions causing the transceiver to communicate over one directional beam of a plurality of directional beams. The beam controller determines a change in the positional information. Based on the change to the positional information, the beam controller determines a directional beam of the plurality of directional beams. The beam controller further generates the communication instructions identifying the determined directional beam, and provides the communication instructions to the transceiver.

Abstract: The disclosed handheld controllers may include at least one finger force-feedback mechanism. The finger force-feedback mechanism may include a rotational element positioned to have an axis of rotation that is located along a palm side of a finger of an intended user's hand when holding the handheld controller, a proximal linkage element positioned and configured to rotate with the intended user's finger about the major knuckle when the user squeezes the handheld controller, and a distal linkage element positioned and configured to rotate relative to the proximal linkage element with the intended user's finger about the second knuckle when the user squeezes the handheld controller. Various other handheld controllers, artificial-reality systems, and methods are also disclosed.