Patent Description:
Electronic equipment such as computers and head-mounted display systems are sometimes controlled using input-output devices such as gloves. A glove may have sensors that detect user hand motions. The user hand motions can be used in controlling electronic equipment.

The use of wearable devices to gather input for controlling electronic equipment can pose challenges. If care is not taken, a device such as a glove may affect the ability of a user to feel objects in the user's surroundings, may be uncomfortable to use, or may not gather suitable input from the user. <CIT> discloses a method and apparatus of using a wearable remote interface device capable of detecting inputs from movements. The wearable remote interface device, which could be attached to a finger or a hand or any parts of a body, includes a sensor, a filter, an input identifier, and a transmitter. The sensor, in one embodiment, is capable of sensing the movement of the finger or any part of body in which the wearable remote interface device is attached with. Upon detecting the various movements associated with the finger, the filter subsequently removes any extraneous gestures from the detected movements. The input identifier, which could be a part of the filter, identifies one or more user inputs from the filtered movements. The transmitter transmits the input(s) to a processing device via a wireless communications network. <CIT> discloses a computer or video game device for generating hand manipulated data. The device consists of one or more sensors that are mounted on the human hand. The sensors are conveniently located for easy access and manipulation by opposing fingers on the same hand that the sensors are mounted on. This arrangement overcomes the limitations of a tabletop computer mouse by not requiring a planar surface, and by not requiring the user to hold onto the device. Additionally, the sensors are located in such a way that they do not impede standard office procedures such as using a computer keyboard, writing with a pen, holding a phone, etcetera. The device can also be quickly and easily attached or removed by the user. Various embodiments of the invention include "wired", "wireless", multiple finger, universal right or left-hand, universal finger or thumb application, and universal side or top mounted sensors. Existing technologies and manufacturing techniques are utilized to minimize cost. Uses include personal computer, video game, and industrial applications. <CIT> discloses an invention that can be embodied in a wearable device or system for measuring finger motion and recognizing hand gestures comprising a distal loop which encircles the intermediate phalanx of a finger, a proximal loop which encircles the proximal phalanx of the finger, a joint-spanning strip which connects these two loops, and a bend sensor which is part of the joint-spanning strip. Changes in energy transmitted through, or generated by, the bend sensor are used to measure the motion and/or configuration of the proximal interphalangeal joint. <CIT> relates to enabling measurement of finger touch pressure without attaching sensor on the touched surface or losing sense of touching by providing a strain gauge attached to the distorted body. <CIT> relates to a tactile feedback man-machine interface device which provides tactile feedback to various sensing body parts. <CIT> discloses a finger stimulus presentation device capable of imparting a mechanical stimulus to a finger while mounted thereon and minimizing loss to the usability of the finger.

A finger-mounted device may include finger-mounted units coupled to control circuitry. The control circuitry wirelessly transmit information gathered with the finger mounted units to an external device to control the external device. The control circuitry also use the finger-mounted units to provide a user's fingers with feedback such as haptic feedback. For example, the control circuitry may supply haptic output to a user's fingers based on wirelessly received information from the external device. The haptic output may correspond to virtual reality or augmented reality haptic output.

The finger-mounted units each have a body. The body serves as a support structure for components such as force sensors, accelerometers, and other sensors and for haptic output devices. During operation, a user may wear the finger mounted units on the tips of the user's fingers while interacting with external objects.

The body of each finger-mounted unit have sidewall portions coupled by portion that rests adjacent to a user's fingernail. A user's fingertip may be received between the sidewall portions. The body may be formed from deformable material such as metal or may be formed from adjustable structures such as sliding body portions that are coupled to each other using magnetic attraction, springs, or other structures. This allows the body of the finger-mounted unit to be adjusted to accommodate different finger sizes.

The body of each finger-mounted unit have a U-shaped cross-sectional profile that leaves the finger pad of each finger exposed when the body is coupled to a fingertip of a user's finger. The control circuitry may gather lateral finger movement input using the sensors and mag provide haptic output using the haptic output device. The present invention is described by the independent claims and the preferred embodiments are described in the dependent claims.

Wearable electronic devices may be used to gather input from a user and may be used to provide haptic output or other output to the user. For example, a wearable device such as a finger-mounted device may be used to gather input from a user's fingers as the user interacts with surfaces in the user's environment and may be used to provide clicks and other haptic output during these interactions. The input that is gathered in this way may include information on how firmly a user is pressing against objects (finger press input), finger tap input associated with light taps of a user's finger against a surface, lateral finger movement information such as shear force information indicating how firmly a user is pressing their finger sideways on a surface, and other user input. Haptic output may be provided to the user to confirm to the user that a light tap input has been recognized or to otherwise provide feedback to the user. The haptic feedback may provide the user with a sensation of tapping on a physical keyboard or other input device with a movable button member even when the user is tapping on a hard flat surface such as a tabletop. The haptic output provided with the wearable electronic device to the user may be virtual reality haptic output or augmented reality haptic output that is provided while a user is wearing a head-mounted display or other device that creates a virtual reality or augmented reality environment for a user.

To allow the user to feel real-world objects accurately, the finger-mounted device may have a U-shaped cross-sectional profile or other shape that allows underside portions of the user's fingertips to be exposed to the environment. Sensor components for the finger-mounted device may be formed from force sensors, optical sensors, and other sensors. Haptic output devices may include piezoelectric actuators and other components that provide haptic output. In some configurations, a piezoelectric device or other component may be used both to provide haptic output (when driven with an output signal) and to gather force sensor input.

A finger-mounted device may be used to control a virtual reality or augmented reality system, may provide a user with the sensation of interacting on a physical keyboard when the user is making finger taps on a table surface (e.g., a virtual keyboard surface that is being displayed in alignment with the table surface using a head-mounted display), may allow a user to supply joystick-type input using only lateral movement of the user's fingertips, may gather force sensor measurements (user finger press force measurements) that are used in controlling other equipment, and/or may be used in gathering input and providing a user with haptic output in other system environments.

<FIG> is a diagram of an illustrative system that includes a wearable device such as a finger-mounted device. As shown in <FIG>, system <NUM> may include a finger-mounted device such as device <NUM> that interacts with electronic equipment such as electronic device <NUM>. Finger-mounted device <NUM> may include sensors such as force sensors <NUM>, haptic output devices <NUM>, and control circuitry <NUM>. Components such as these may be mounted on the body parts of a user (e.g., on a user's fingertips) using housing structures (sometimes referred to as body structures or body members). Housing structures may be formed for portions of device <NUM> that reside on one or more fingers. For example, device <NUM> may include a separate body member and associated components for each of multiple different fingers of a user. The housing structures may be formed from metal, polymer, fabric, glass, ceramic, other materials, or combinations of these materials. In some configurations, wireless or wired links may be used to route signals to and from fingertip components to other portions of device <NUM> (e.g., a portion of device <NUM> that is located on the rear of a user's hand, etc.).

If desired, device <NUM> may include input-output devices other than force sensors <NUM>. For example, device <NUM> may include optical sensors (e.g., sensors that detect light or sensors that emit light and detect reflected light), image sensors, status indicator lights and displays (e.g., light-based components such as light-emitting diodes that emit one or more regions of light, pixel arrays for displaying images, text, and graphics, etc.), may include buttons (e.g., power buttons and other control buttons), audio components (e.g., microphones, speakers, tone generators, etc.), touch sensors, sensors for detecting position, orientation, and/or motion (e.g., accelerometers, magnetic sensors such as compass sensors, gyroscopes, inertial measurement units that contain some or all of these sensors), muscle activity sensors (EMG) for detecting finger actions, and/or other circuitry for gathering input.

Haptic output devices <NUM> may be electromagnetic actuators (e.g., vibrators, linear solenoids, etc.), may be piezoelectric devices (e.g., piezoelectric devices that are separate from force sensing piezoelectric devices in device <NUM> and/or piezoelectric devices that serve both as haptic output devices and as force sensors), may be components that produce haptic output using heat-induced physical changes (e.g., by heating shape memory alloys), may be electroactive polymer components, or may be other suitable components that produce haptic output.

Control circuitry <NUM> may include storage and processing circuitry for supporting the operation of device <NUM>. The storage and processing circuitry may include storage such as nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in control circuitry <NUM> may be used to gather input from sensors and other input devices and may be used to control output devices such as haptic output devices <NUM>. The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors and other wireless communications circuits, power management units, audio chips, application specific integrated circuits, etc..

Control circuitry <NUM> may include antennas, radio-frequency transceiver circuitry, and other wireless communications circuitry and/or wired communications circuitry to support communications with external equipment such as electronic device <NUM>. Control circuitry <NUM> may, for example, support bidirectional communications with device <NUM> over a wireless local area network link, a cellular telephone link, or other suitable wired or wireless communications link (e.g., a Bluetooth® link, a WiFi® link, a <NUM> link, etc.). Device <NUM> may be, for example, a tablet computer, a desktop computer, a cellular telephone, a head-mounted device such as a head-mounted display, wearable equipment, a wrist watch device, a set-top box, a gaming unit, a television, a display that is coupled to a desktop computer or other electronic equipment, a voice-controlled speaker, home automation equipment, an accessory (e.g., ear buds, a removable case for a portable device, etc.), or other electronic equipment. Device <NUM> may include input-output circuitry such as sensors, buttons, cameras, displays, and other input-output devices and may include control circuitry (e.g., control circuitry such as control circuitry <NUM>) for controlling the operation of device <NUM>. Control circuitry <NUM> may include wireless power circuitry (e.g., a coil and rectifier for receiving wirelessly transmitted power from a wireless power transmitting device that has a corresponding wireless power transmitting circuit with a coil). During wireless power transmission operations (e.g., inductive power transmission), wireless power may be provided to device <NUM> and distributed to load circuitry in device <NUM> (e.g., circuitry <NUM>, devices <NUM>, sensors <NUM>, etc.). Circuitry <NUM> may include energy storage circuitry (e.g., batteries and/or capacitors) for storing power from a wired power device and/or a wireless power transmitting device.

Device <NUM> may be coupled to one or more additional devices in system <NUM>. For example, a head-mounted device with a display may be used for displaying visual content (virtual reality content and/or augmented reality content) to a user. This head-mounted device may be coupled to an electronic device such as a cellular telephone, tablet computer, laptop computer, or other equipment using wired and/or wireless communications links. Devices <NUM> may communicate with device <NUM> to gather input (e.g., user finger position information) and to provide output (e.g., using haptic output components in device).

During operation, control circuitry <NUM> of device <NUM> use communications circuitry to transmit user input such as force sensor information and information from other sensors to device <NUM> to use in controlling device <NUM>. Information from the sensors and other input devices in device <NUM> and/or information from device <NUM> may be used by control circuitry <NUM> in determining the strength and duration of haptic output supplied to the user with haptic output devices <NUM>.

<FIG> is top view of a user's hand and an illustrative finger-mounted device. As shown in <FIG>, device <NUM> may be formed from one or more finger-mounted units <NUM> mounted on fingers <NUM> of the user. Units <NUM> may, for example, be mounted on the tips of fingers <NUM> (e.g., overlapping fingernails <NUM>). Some or all of control circuitry <NUM> may be contained in units <NUM> or may be mounted in separate housing structures (e.g., part of a wrist band, a glove, a partial glove such as a fingerless glove or glove in which portions have been removed under the pads of a user's finger tips, etc.). Signal paths such as signal paths <NUM> may be used in interconnecting the circuitry of units <NUM> and/or additional circuitry such as control circuitry <NUM> that is located out of units <NUM>.

Signal paths <NUM> may include wired or wireless links. Wired paths may be formed, for example, using metal traces on a printed circuit such as a flexible printed circuit, using wires, using conductive strands (e.g. wires or metal-coated polymer strands) in woven, knit, or braided fabric, and/or using other conductive signal lines. In configurations in which some or all of control circuitry <NUM> is located outside of units <NUM>, signal paths such as signal paths <NUM> may run across some or all of user's hand <NUM> to couple the circuitry of units <NUM> to this control circuitry. Configuration in which control circuitry <NUM> is located in one or more units <NUM> and in which these units <NUM> are interconnected by wired or wireless paths <NUM> may also be used, if desired.

When units <NUM> are located on the user's fingertips, components in units <NUM> may sense contact between the user's fingertips and external surfaces. In some configurations, a user's fingertip (e.g., the pad of the user's fingertip) may contact a surface and, while the fingertip is in contact with the surface, a user may move the fingertip laterally in lateral directions such as lateral directions <NUM> and <NUM> of <FIG>. The lateral movement of the fingertip while the pad of the fingertip is in contact with a surface (e.g., movement of the fingertip in dimensions parallel to the plane of the surface being contacted) may generate shear forces that can be detected by the components of one or more units <NUM>. This allows the user's own fingertip to be used as a pointing device (e.g. to be used as a joystick) that can control an on-screen cursor or other adjustable system feature in a device such as device <NUM> of <FIG>. In some configurations, units <NUM> may be worn on portions of hand <NUM> other than the fingertips of fingers <NUM>. For example, units <NUM> may be worn elsewhere along the lengths of fingers <NUM>, as shown by illustrative units <NUM>' of <FIG>. If desired, units <NUM> and <NUM>' may be used together in device <NUM> (e.g., to gather information from multiple finger locations). Illustrative configuration in which units <NUM> are mounted at the tips of fingers <NUM> may sometimes be described herein as an example.

Units <NUM> may partly or completely surround the tips of fingers <NUM>. <FIG> is a cross-sectional view of an illustrative finger-mounted device (unit <NUM>) on a user's finger <NUM> in an arrangement in which the body of unit <NUM> surrounds finger <NUM> (e.g., in which unit <NUM> has portions of the top, sides, and lower finger pad portion of finger <NUM>). Unit <NUM> of <FIG> may, as an example, be formed from a soft elastomeric material, fabric, or other flexible material that allows the user to feel surfaces through unit <NUM>. If desired, sensors, haptic devices, and or other components may be mounted under the pad of finger <NUM> in locations such as location <NUM>.

If desired, units <NUM> may have a U-shaped cross-sectional profile so that units <NUM> cover only the tops and/or sides of the user's fingers while the pads of the user's fingertips are exposed and not covered by any portions of device <NUM>. Units <NUM> with this type of configuration may allow the user to touch surfaces with the user's own skin, thereby enhancing the user's sensitivity to the environment in which device <NUM> is being used. For example, units <NUM> that cover only the tops and sides of a user's fingertips may allow the pads of the user's finger to detect small surface imperfections on a touched surface, slight irregularities in surface texture, and other details that might be obscured in a configuration in which the pads of the user's fingers are covered.

<FIG> is a perspective view of an illustrative unit <NUM> for finger-mounted device <NUM> in which body <NUM> of unit <NUM> is configured to only partly surround a user's fingertip. As shown in <FIG>, body <NUM> include side portions such as sidewall portions <NUM> (e.g., portions that contact the sides of a user's finger) and portions such as coupling portion <NUM> (e.g., a slightly bowed portion that covers the top of a user's fingertip or, in some configurations, that covers the pad of the user's fingertip at the bottom of the user's fingertip). Potion <NUM> may support sidewall portions <NUM> adjacent to opposing left and right sides of a user's finger. Openings such as optional openings <NUM> may be formed in body <NUM> to facilitate bending of a metal member or other structure forming body <NUM>. Body <NUM> may be tapered to facilitate mounting of body <NUM> on a user's fingertip (e.g., body <NUM> may have a wider portion of width W1 and a narrower portion for the outermost tip of the user's finger with a width W2 that is less than W1).

<FIG> is an end view of an illustrative unit such as unit <NUM> of <FIG> in a configuration in which a user's finger (e.g., finger pad <NUM> at the bottom of the tip of finger <NUM>) is resting lightly on an external surface such as surface <NUM>. As shown in <FIG>, body <NUM> of unit <NUM> may have a U-shaped cross-sectional profile that holds body <NUM> to finger <NUM> with a friction fit. With this configuration, the open side of U-shaped body <NUM> may face downward to expose finger pad <NUM>.

When a user moves finger <NUM> laterally in direction <NUM> as shown in <FIG>, shear forces are generated. Force sensors (e.g., in sidewalls <NUM>) detects this shear force and may use the detected shear force to measure the user's lateral finger movement.

<FIG> shows how finger press input force against surface <NUM> may be measured. When a user presses finger <NUM> downwardly against surface <NUM> in direction <NUM>, portions of finger <NUM> will be forced outwardly in directions <NUM> (e.g., symmetrically). Force sensors in sidewall portions <NUM> of body <NUM> of unit <NUM> can detect these outward forces and can use this information to quantify the amount of downward force applied in direction <NUM>.

<FIG> is a cross-sectional view of an illustrative finger-mounted unit showing illustrative mounting locations for electrical components. As shown in <FIG>, components <NUM> may be mounted on the inner and/or outer surfaces of body <NUM> (e.g., on sidewall portions <NUM> and/or upper portion <NUM> of body <NUM>). Force sensors is mounted on sidewall portions <NUM> to detect finger forces as described in connection with <FIG>. As another example, haptic output devices <NUM> may be mounted on sidewall portions <NUM> (e.g., on an outer surface, on an inner surface facing an opposing force sensor on an opposing inner sidewall surface, on the upper or lower surface of portion <NUM> of body <NUM>, etc.). Components <NUM> may include an accelerometer or other sensor that detects motion, orientation, and/or position for finger <NUM>. For example, an accelerometer may be located on the upper surface of portion <NUM> or elsewhere in unit <NUM>. When a user taps lightly on surface <NUM> (<FIG>) to provide device <NUM> with finger tap input, the accelerometer may detect a sudden change in the speed of unit <NUM> (e.g., a peak in measured acceleration) corresponding to the tap. When both force sensors and accelerometers are present in device <NUM>, device <NUM> can measure finger press input (downward force), lateral finger motion input (shear forces), and finger tap input (accelerometer output signal peaks).

Other components <NUM> that may be supported by body <NUM> include components for wired and/or wireless communications circuitry and/or other circuitry <NUM> (e.g., circuitry supported by body portion <NUM>), batteries, optical sensors (e.g., light-emitting and light-detecting components on portion <NUM>), a strain gauge (e.g., a strain gauge that extends across some or all of the width of portion <NUM> and which may optionally be mounted on an upper surface of portion <NUM> to measure strain resulting from movement of sidewall portions <NUM> relative to portion <NUM> and corresponding flattening of the bowed shape of portion <NUM>), and/or light-emitting devices such as light-emitting diodes or passive marker structures on the top of portion <NUM> or elsewhere in body <NUM> to facilitate camera-based position monitoring of the locations and/or orientations of units <NUM> (e.g., position monitoring using image sensors in device <NUM> or other external equipment).

<FIG> is a side view of the illustrative finger-mounted unit of <FIG>. As shown in <FIG>, sensors or other components <NUM> may be segmented along the side of body sidewall portion <NUM> of unit <NUM>. If desired, the sensors or other components <NUM> supported by body <NUM> may have multiple subcomponents such as components <NUM>'. For example, a force sensor and/or haptic device on sidewall <NUM> of <FIG> may have multiple components <NUM>' each of which produces a separate respective force sensor measurement and/or each of which produces a separate respective haptic output. This allows more detailed measurements to be made on the forces created during operation (e.g., to help accurately acquire information on the location of a finger press within the tip of the user's finger by comparing where different portions of the user's finger press outwardly in directions <NUM> of <FIG>) and allows more detailed haptic feedback to be provided to the user. If desired, multiple sensors such as force sensors and/or multiple haptic output devices or other components <NUM>' may be placed on upper portion <NUM> of body <NUM>, as shown in <FIG>.

Piezoelectric components may be used in forming force sensors (by converting applied force into electrical signals for processing by control circuitry <NUM>) and haptic output devices (by converting electrical signals from control circuitry <NUM> into forces applied to the user's hand). An illustrative piezoelectric device is shown in <FIG>. Piezoelectric device <NUM> of <FIG> has a support structure such as support structure <NUM> with a beam-shaped portion such as portion <NUM>. Piezoelectric layers <NUM> and <NUM> may be formed on opposing surfaces of beam portion <NUM>. In a force sensor, bending of beam <NUM> due to applied force will induce compressive stress in layer <NUM> and tensile stress in layer <NUM>, which can be measured and evaluated using circuitry <NUM> to produce a force reading. In a haptic output device, voltages may be applied to layers <NUM> and <NUM> by control circuitry <NUM> that cause layer <NUM> to contract and that cause layer <NUM> to expand, thereby deflecting beam portion <NUM> as shown in <FIG>. If desired, piezoelectric components such as component <NUM> may have other shapes such as the illustrative disk shape of <FIG>. In a force sensor with this type of arrangement, applied force to component <NUM> along axis <NUM> may produce compressive and tensile stresses in layers <NUM> and <NUM> that can be measured by control circuitry <NUM>. In a haptic output device with this type of arrangement, applied electrical signals to layers <NUM> and <NUM> can be used to deflect component <NUM> up or down along axis <NUM>.

Capacitive sensing techniques may be used to measure force. Consider, as an example, the capacitive force sensor of <FIG>. Capacitive force sensor <NUM> has a substrate such as substrate <NUM> (e.g., a flexible or rigid printed circuit, etc.). One or more capacitive force sensor elements <NUM> may be formed on substrate <NUM>. For example, a one-dimensional or two-dimensional array of force sensor elements <NUM> may be formed on substrate <NUM> that are coupled to capacitive measurement circuitry in control circuitry <NUM> using signal lines formed from metal traces on substrate <NUM>. Each capacitive force sensor element <NUM> may have capacitive force sensing electrodes such as electrodes <NUM> and <NUM> separated by a compressible material <NUM> (e.g., polymer foam, an elastomeric material such as silicone, etc.). Control circuitry <NUM> can measure the capacitance between the pair of electrodes in each element <NUM>. In response to applied force on a given element <NUM>, compressible material <NUM> in that element will become thinner and the electrode spacing will reduce, leading to an increase in capacitance that control circuitry <NUM> can measure to determine the magnitude of the applied force.

In addition to or instead of using piezoelectric components for force sensing and/or providing haptic output, and in addition to or instead of using capacitive force sensor arrangements for force sensing, device <NUM> may use other force sensing and/or haptic output devices. For example, force may be sensed using soft piezoelectric polymers, microelectromechanical systems (MEMs) force sensors, a strain gauge (e.g., a planar strain gauge mounted to the surface of portion <NUM>), resistive force sensors, optical sensors that measure skin color changes due to pressure variations, and/or other force sensing components. Haptic output devices may be based on electromagnetic actuators such as linear solenoids, motors that spin asymmetrical masses, electroactive polymers, actuators based on shape memory alloys, pneumatic actuators, and/or other haptic output components.

As shown in <FIG>, unit <NUM> may be worn in a configuration in which portion <NUM> is adjacent to fingernail <NUM> and in which finger pad <NUM> is exposed. Unit <NUM> may be worn in this way when it is desired to maximize the user's ability to feel objects in the user's environment. <FIG> shows how unit <NUM> may be worn in a flipped configuration in which unit <NUM> is upside down in comparison to the orientation of <FIG> and in which portion <NUM> is adjacent to finger pad <NUM>. Unit <NUM> may be worn in this way to enhance haptic coupling between haptic output component(s) on body <NUM> and finger pad <NUM> (e.g., when device <NUM> is being used in a virtual reality system and in which haptic output is being provided to a user in the absence of a user's actual touching of external surfaces). <FIG> shows how sidewall portions of unit <NUM> may have a rotatable flap such as flaps 40P or 40P'. The flap may rotate into position 40F (e.g., a position in which a haptic output device or other component <NUM> is adjacent to finger pad <NUM>).

Haptic output may be provided in the form of one or more pulses in the displacement of the haptic output device(s) of unit <NUM>. <FIG> is a graph of an illustrative drive signal DR of the type that may be used in controlling a haptic output device in unit <NUM>. In the example of <FIG>, the drive signal includes a pair of closely spaced pulses <NUM> (e.g., two pulses <NUM> that occur at a rate of about <NUM>-<NUM>, at least <NUM>, less than <NUM>, or other suitable frequency). There are two pulses in the group of pulses (group <NUM>) of <FIG>, but fewer pulses or more pulses may be included in the drive signal DR, if desired. Human fingers typically exhibit sensitivity to signals at <NUM>-<NUM> and are particularly sensitive to signals in the range of <NUM>-<NUM>. Drive signals DR at other frequencies may, however be used if desired. Each pulse <NUM> may have the shape of a truncated sinusoidal wave, a Gaussian shape, or other suitable shape.

<FIG> is a perspective view of an illustrative finger-mounted device arrangement in which unit <NUM> has frame members <NUM> that help support other portions of body <NUM>. Frame members <NUM> may be elongated structures such as deformable metal wires that overlap a deformable structure such as a layer of plastic or sheet metal. The presence of frame members <NUM> may help allow a user to controllably deform body <NUM> to produce a satisfactory friction fit of body <NUM> onto the tip of the user's finger <NUM>.

In the example of <FIG>, pneumatic components <NUM> have been formed on the inner surfaces of sidewall portions <NUM> of body <NUM>. When inflated, pneumatic components <NUM> (e.g., balloons) expand to position <NUM>', thereby helping to hold unit <NUM> on a user's finger.

<FIG> is a view of an illustrative configuration for unit <NUM> in which a layer (layer <NUM>) of foam or other compressible material (e.g., silicone or other elastomeric material) has been placed on the inner surfaces of sidewall portions <NUM> and portion <NUM> of body <NUM>. When unit <NUM> is placed on a user's finger, compressible layer <NUM> can conform to the shape of the user's finger to help hold unit <NUM> on the user's finger.

<FIG> shows how a threaded fastener such as nut <NUM> may be used in adjusting the width of body <NUM> to help hold body <NUM> on a user's finger. Nut <NUM> may be received on threads on portion <NUM> of body portion <NUM>. When nut <NUM> is rotated in directions <NUM> about axis <NUM>, portions <NUM> of body portion <NUM> will be pulled together or pressed apart, depending on the direction of rotation of nut <NUM>. When portions <NUM> are pulled towards each other, body sidewall portions <NUM> will be biased inwardly in directions <NUM>, thereby reducing the separation distance between body sidewall portions <NUM> and securing unit <NUM> on the user's finger.

In the example of <FIG>, unit <NUM> has portions that slide with respect to each other. In particular, body portion <NUM> may have a first portion such as portion <NUM>-<NUM> that slides relative to a second portion such as portion <NUM>-<NUM> to adjust the width of unit <NUM> and therefore the separation distance of sidewall portions <NUM> to a comfortable size. Areas <NUM> of portions <NUM>-<NUM> and <NUM>-<NUM> may exhibit magnetic attraction that holds portions <NUM>-<NUM> and <NUM>-<NUM> together and helps secure unit <NUM> on a user's fingers in a desired configuration.

<FIG> shows how a biasing structure such as spring <NUM> can pull portions <NUM>-<NUM> and <NUM>-<NUM> towards each other in directions <NUM> to secure unit <NUM> on the user's finger.

<FIG> is a cross-sectional side view of unit <NUM> in an illustrative configuration in which body <NUM> is formed from deformable structures such as deformable metal layer(s). With this type of arrangement, wall portions <NUM> can be bent inwardly in directions <NUM> to positions such as positions <NUM>' when it is desired to secure unit <NUM> on a finger of the user. Body <NUM> in this type of arrangement may include a metal layer that coated with elastomeric material. As shown in <FIG>, for example, body <NUM> may include central metal layer <NUM> and polymer coating layers 38P.

<FIG> is a side view of an illustrative finger-mounted unit (unit <NUM>') in a location that is on finger <NUM> but not overlapping fingernail <NUM> at the tip of finger <NUM>. Device <NUM> may have one or more finger-mounted units and these units may, in general, be located at the user's fingertips, at other locations on the user's fingers <NUM>, etc..

<FIG> shows how components <NUM> may include optical sensors that can gather touch input from an area such as area 32T on the back of user's finger <NUM>. The optical sensors may include light-emitting diodes, lasers, or other light-emitting components (e.g., infrared light-emitting diodes) and may include light-detecting components such as solid state light detectors (e.g., photodiodes, phototransistors, etc.). The light-emitting components may emit light along paths <NUM> and the light-detecting components may detect reflected light along paths <NUM> due to the presence of a user's fingertip or other external object that intersects one of these paths <NUM>. Paths <NUM> may be parallel to each other and/or may include angled paths (e.g., to facilitate triangulation). By processing the optical sensor signals from the optical sensors in this type of arrangement, control circuitry <NUM> can measure the location of an object in area 32T (e.g., in one or two dimensions). This allows area 32T to be used as a miniature portable track pad.

As shown in <FIG>, external equipment such as electronic device <NUM> in system <NUM> may contain sensors such as one or more cameras <NUM> (e.g., visual light cameras, infrared cameras, etc.). Electronic device <NUM> may, as an example, be a head-mounted device such as augmented reality (mixed reality) or virtual reality googles (or glasses, a helmet, or other head-mountable support structures). Visual markers <NUM> may be placed in the user's working environment. Markers <NUM> may be, for example, passive visual markers such as bar codes, cross symbols, or other visually identifiable patterns and may be applied to a tabletop or other work surface. If desired, markers <NUM> may be formed as part of a work surface pad such as pad <NUM>. Markers may also be placed on finger-mounted device(s) <NUM> (see, e.g., unit <NUM> of <FIG>).

Markers <NUM> may, if desired, include light-emitting components (e.g., visual light-emitting diodes and/or infrared light-emitting diodes modulated using identifiable modulation codes) that are detected using cameras. Markers <NUM> may help inform system <NUM> of the location of the user's virtual work surface and one or more of the user's fingers as a user is interacting with a computer or other equipment in system <NUM>.

Visual markers <NUM> on units <NUM> and/or inertial measurement units in units <NUM> (e.g., accelerometers, compasses, and/or gyroscopes) may be used in tracking the user's finger locations (e.g., the locations of finger-mounted units <NUM>) relative to markers <NUM> on the user's work area. At the same time, system <NUM> may display associated visual content for the user. The user may interact with the displayed visual content by supplying force input, motion input (e.g., air gestures), taps, shearing force input, and other input gathered from units <NUM> by inertial measurement units in units <NUM> and/or force sensors and other sensors in device(s) <NUM>.

For example, information on the location of finger-mounted units <NUM> relative to markers <NUM> may be gathered by control circuitry in device <NUM> or other electronic equipment in system <NUM> (e.g., a computer, cellular telephone, or other electronic device coupled to device <NUM>) during operation of system <NUM> while monitoring units <NUM> for force input, gesture input (e.g., taps, three-dimensional air gestures, etc.) that indicate that a user has selected (e.g., highlighted), moved, or otherwise manipulated a displayed visual element and/or provided commands to system <NUM>. As an example, a user may make an air gesture such as a left hand wave to move visual content to the left. System <NUM> may use inertial measurement units in units <NUM> to detect the left hand wave gesture and can move visual elements being presented to the user with a display in device <NUM> in response to the left hand wave gesture. As another example, a user may select a visual element in the user's field of view by tapping on that element.

In this way, control circuitry in device <NUM>, and/or other control circuitry in system <NUM> may allow a user to manipulate visual elements being viewed by the user (e.g., virtual reality content or other visual content being presented with a head-mounted device such as augmented reality googles or other device <NUM> with a display). If desired, a camera such as camera <NUM> may face the eyes of a user (e.g., camera <NUM> or other visual tracking equipment may form part of a gaze tracking system). The camera and/or other circuitry of the gaze tracking system may monitor the direction in which a user is viewing real-world objects and visual content. As an example, a camera may be used to monitor the point of gaze (direction of gaze) of a user's eyes as the user is interacting with virtual content presented by device <NUM> and as the user is interacting with real-life content. Control circuitry in device <NUM>, unit <NUM>, or other electronic equipment may measure the amount of time that a user's gaze dwells in particular locations and can use this point-of-gaze information in determining when to select virtual objects. Virtual objects can also be selected when it is determined that a user is viewing a particular object (e.g., by analyzing point-of-gaze information) and when it is determined that a user has made a voice command, finger input, button press input, or other user input to select the particular object that is being viewed. Point-of-gaze information can also be used during drag and drop operations (e.g., to move virtual objects in accordance with movement of the point-of-gaze from one location in a scene to another.

<FIG> is a diagram showing how visual elements can be manipulated by a user who is wearing finger-mounted device <NUM> on finger <NUM>. Visual elements such as illustrative element <NUM> (e.g., an icon representing a desktop application, a file folder, a media file or other file, or other information) may be displayed using a display in device <NUM>. Workspace <NUM> may have markers <NUM>, if desired. A user may select visual items using taps, force input, persistent touch input, air gestures, and/or other user input that is detected using unit(s) <NUM> and/or other equipment in system <NUM> such as cameras in device <NUM>.

Visual items such as illustrative element <NUM> can be selected (e.g., to launch an application, to highlight an item, etc.), moved, deleted, marked, and/or may otherwise be manipulated by a user using gestures (e.g., drag and drop gestures, etc.) and other user input. For example, a user may drag and drop visual element <NUM> to location <NUM> on workspace <NUM> using the tip of finger <NUM> as an input device (while the location of the tip of finger <NUM> is monitored using unit <NUM>). Unit <NUM> on finger <NUM> may supply haptic output (e.g., feedback that creates a virtual detent as a user drags element <NUM> past a predetermined boundary). This feedback may be accompanied by visual feedback (e.g., changes in the color and other aspects of the appearance of element <NUM> that are synchronized with haptic feedback). If desired, device <NUM> may display visual elements in a virtual workspace that extends upwards in front of (and, if desired, to the left and right sides of and/or behind) the user, as shown by virtual workspace <NUM>'. A user may drag and drop visual element <NUM> to a location in virtual workspace <NUM>' (e.g., to place element <NUM> in location <NUM>). Items in workspace <NUM>' may be manipulated using air gestures or other input (e.g., voice input, etc.). For example, a user may use a rightwards swipe to move items in workspace <NUM>' to the right.

As the user interacts with virtual content using unit <NUM>, the user may contact a table surface or other surface with the surface of finger <NUM>. For example, the finger pulp of finger pad <NUM> at the bottom of the tip of finger <NUM> may contact the table surface and may be compressed by the force imparted by finger <NUM>. To lessen fatigue and improve a user's experience when providing finger press input, the forces imposed on a user's fingers as the user is providing input to an electronic device can be modified using components coupled to a user's finger and/or components in the electronic device. As an example, components in a finger-mounted device such as unit <NUM> may be used to help soften the impact between a user's finger and the input surface (e.g., a surface associated with workspace <NUM>).

An unmodified finger impact event may be characterized by an abrupt force-versus-displacement profile (e.g., rapidly rising force on a user's finger when traveling a relatively short distance toward an input surface). By modifying these forces, a user may be provided with softer finger-to-input-surface interactions, with finger sensations that mimic the action of clicking on a physical button, and/or other finger sensations. With one illustrative configuration, actuators in unit <NUM> (e.g., piezoelectric actuators, electromechanical actuators, etc.) can squeeze (or not squeeze) a user's fingertip just before the fingertip touches a surface, thereby selectively modifying the user's experience as the fingertip contacts the surface. If, for example, actuators on the left and right side of unit <NUM> squeeze inwardly on finger <NUM> just before finger pad <NUM> touches surface <NUM> and thereby cause the pulp of finger <NUM> to protrude towards surface <NUM> prior to contact, the user may experience a softer impact with surface <NUM> than if the actuators do not squeeze inwardly on the finger. Modifications such as these may be made dynamically as a user interacts with virtual content.

<FIG> shows how visual element <NUM> may be a list containing multiple items. A desired item in the list may be selected by causing finger <NUM> to hover (linger) over the desired item for more than a predetermined amount of time (as shown by illustrative selected item <NUM>). Finger position information gathered by system <NUM> (e.g., an inertial measurement in unit <NUM>, a camera measuring a marker on a unit <NUM>, etc.) may be used in determining which list items are to be selected, highlighted, etc. Gestures may be used to scroll through items.

If desired, system <NUM> (e.g., cameras in device <NUM>, etc.) can detect the position of units <NUM> using optical sensing. As shown in <FIG>, units <NUM> may include visual markers <NUM> (e.g., passive markers, visible or infrared light-emitting diodes, etc.). Markers <NUM> may be placed on portions of unit <NUM> in device <NUM> such as portions <NUM> and <NUM>. Markers <NUM> may be arranged in a recognizable asymmetrical pattern to help avoid creating ambiguous position data.

<FIG> is a cross-sectional side view of unit <NUM> in an illustrative configuration in which upper portion <NUM> has thicker portions 42N in which components <NUM> have been housed and a thinner portion to facilitate bending such as thinner portion 42T. Thinner portion 42T may be formed from a flexible material such as metal, polymer, and/or other materials and may be interposed between portions 42N.

Claim 1:
A finger-mounted device configured to be worn on a finger (<NUM>) of a user, the finger-mounted device comprising:
a body (<NUM>) having a U-shaped cross section and configured to be coupled to the finger (<NUM>), covering a fingernail of the finger (<NUM>) and leaving a finger pad (<NUM>) of the finger (<NUM>) exposed, the body (<NUM>) comprising first and second sidewall portions (<NUM>) that contact sides of the finger and that are coupled by an upper portion (<NUM>), the first and second sidewall portions having force sensors (<NUM>), wherein the force sensors (<NUM>) is configured to detect shear forces generated by lateral finger movement;
a haptic output device (<NUM>) coupled to the body (<NUM>); and
control circuitry (<NUM>) configured to:
gather finger input using the force sensors (<NUM>), wherein the finger input includes the lateral finger movement;
provide haptic output to the user's finger (<NUM>) using the haptic output device (<NUM>); and
wirelessly transmit control signals to an external electronic device based on the finger input.