PATENT DOCUMENT

Publication Number: US-10564724-B1
Application Number: US-201715691545-A
Country: US
Kind Code: B1

Title: Touch-based input device with haptic feedback

Abstract:
An input device, such as a stylus, can include a piezoelectric device for providing haptic feedback and/or detecting user input. The piezoelectric device can be coupled to an inner surface of a housing of the stylus. The piezoelectric device can provide haptic feedback with a force to the housing when an electric voltage is applied to the piezoelectric device. The haptic feedback can provide information to the user relating operation of the stylus with an external device. The piezoelectric device can also produce an electric voltage when an input force is applied to an outer surface of the housing and transmitted to the piezoelectric device. The electric voltage can be used to detect tactile input from a user.

Claims:
What is claimed is: 
     
       1. A stylus, comprising:
 a housing comprising a user grip region on an outer surface of the housing, wherein the housing extends continuously to define an outer periphery of the stylus; and 
 a guidetube coupled to an inner surface of the housing, the guidetube forming an opening to the inner surface of the housing; and 
 a piezoelectric device positioned within the opening and against the inner surface of the housing at the user grip region; 
 wherein the user grip region of the housing is deformable, such that an input force that deforms the user grip region of the housing into the opening is transmitted to the piezoelectric device to produce an electric voltage and such that haptic feedback provided by the piezoelectric device deforms the user grip region away from the opening. 
 
     
     
       2. The stylus of  claim 1 , wherein at least a portion of the inner surface of the housing or at least a portion of an outer surface of the housing is flat. 
     
     
       3. The stylus of  claim 1 , wherein the piezoelectric device extends annularly along an entire perimeter of the inner surface of the housing. 
     
     
       4. The stylus of  claim 3 , further comprising a guidetube extending annularly within the piezoelectric device, wherein the guidetube is coupled to the housing on opposing sides of the piezoelectric device, and wherein the piezoelectric device and the guidetube are radially separated by an annular gap. 
     
     
       5. The stylus of  claim 1 , further comprising an additional piezoelectric device, wherein the piezoelectric device and the additional piezoelectric device are disposed at different circumferential locations along the inner surface of the housing. 
     
     
       6. The stylus of  claim 1 , further comprising an additional piezoelectric device, wherein the piezoelectric device and the additional piezoelectric device are arranged along a line. 
     
     
       7. The stylus of  claim 1 , wherein the piezoelectric device is coupled to and extends between opposing sides of the inner surface of the housing. 
     
     
       8. The stylus of  claim 1 , wherein the piezoelectric device forms a helical shape. 
     
     
       9. A stylus, comprising:
 a housing forming an input component for receiving an input force from a user at a user grip region of the stylus, the housing extending continuously about a longitudinal axis of the stylus to define an outer periphery of the stylus; 
 a piezoelectric device coupled to the input component, wherein the piezoelectric device produces an input signal when the input force is applied to the input component and transmitted to the piezoelectric device, and wherein the piezoelectric device provides haptic feedback to the user via the input component; and 
 a communication component to communicate the input signal to an external device, wherein the haptic feedback is provided in response to an action signal received from the external device. 
 
     
     
       10. The stylus of  claim 9 , wherein the input signal comprises instructions to alter a setting of the external device. 
     
     
       11. The stylus of  claim 9 , wherein the haptic feedback is provided upon confirmation that the input signal has been received by the external device. 
     
     
       12. A method, comprising:
 sensing, with a piezoelectric device of a stylus, an input force applied to a user grip region of the stylus and transmitted to the piezoelectric device, the user grip region being located at a housing of the stylus that extends continuously about a longitudinal axis of the stylus to define an outer periphery of the stylus, the input force deforming the user grip region toward the longitudinal axis; 
 transmitting, from the stylus and to an external device, an input signal as an indication of the input force; 
 receiving an action signal from the external device; and 
 based on the action signal, providing haptic feedback with a force to the user grip region of the stylus by applying an electric voltage to the piezoelectric device to deform the user grip region away from the longitudinal axis. 
 
     
     
       13. The method of  claim 12 , wherein the input signal comprises an indication of an input sensed by the piezoelectric device. 
     
     
       14. The method of  claim 12 , wherein the action signal comprises a confirmation that the input signal was received by the external device. 
     
     
       15. The method of  claim 12 , wherein the input signal comprises instructions for the external device to apply an action upon receipt of an input sensed by a tip sensor at a tip of the stylus. 
     
     
       16. The method of  claim 12 , wherein the transmitting is performed only if the input force exceeds a threshold.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 62/397,263, entitled “TOUCH-BASED INPUT DEVICE WITH HAPTIC FEEDBACK,” filed Sep. 20, 2016, the entirety of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present description relates generally to touch-based input devices, such as styluses, and, more particularly, to touch-based input devices that can provide haptic feedback to a user. 
     BACKGROUND 
     A variety of handheld input devices exist for detecting input from a user during use. For example, a stylus can be utilized to provide input by contacting a touch panel of an electronic device. The touch panel may include a touch sensitive surface that, in response to detecting a touch event, generates a signal that can be processed and utilized by other components of the electronic device. A display component of the electronic device may display textual and/or graphical display elements representing selectable virtual buttons or icons, and the touch sensitive surface may allow a user to navigate the content displayed on the display screen. Typically, a user can move one or more input devices, such as a stylus, across the touch panel in a pattern that the device translates into an input command. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain features of the subject technology are set forth in the appended claims. However, for purpose of explanation, several embodiments of the subject technology are set forth in the following figures. 
         FIG. 1  illustrates a view of a system including a stylus and an external device, according to some embodiments of the subject technology. 
         FIG. 2  illustrates a perspective view of the stylus of  FIG. 1 , according to some embodiments of the subject technology. 
         FIG. 3  illustrates a front sectional view of the section A-A of the stylus of  FIG. 2 , according to some embodiments of the subject technology. 
         FIG. 4  illustrates a side sectional view of the section B-B of the stylus of  FIG. 2 , with a piezoelectric device in a resting state, according to some embodiments of the subject technology. 
         FIG. 5  illustrates a side sectional view of the stylus of  FIG. 2 , with the piezoelectric device in an actuated state, according to some embodiments of the subject technology. 
         FIG. 6  illustrates a side sectional view of the stylus of  FIG. 2 , with the piezoelectric device in a deformed state, according to some embodiments of the subject technology. 
         FIG. 7  illustrates a graph comparing forces applied to a piezoelectric device and output voltages of the piezoelectric device across a span of time, according to some embodiments of the subject technology. 
         FIG. 8  illustrates a graph comparing forces applied to a piezoelectric device and output voltages of the piezoelectric device across a span of time, according to some embodiments of the subject technology. 
         FIG. 9  illustrates a block diagram illustrating the stylus and the external device of  FIG. 1 , according to some embodiments of the subject technology. 
         FIG. 10  illustrates a perspective view of a guidetube, according to some embodiments of the subject technology. 
         FIG. 11  illustrates a front sectional view of a stylus that includes the guidetube of  FIG. 10 , according to some embodiments of the subject technology. 
         FIG. 12  illustrates a side sectional view of the stylus of  FIG. 11 , with a piezoelectric device in a resting state, according to some embodiments of the subject technology. 
         FIG. 13  illustrates a side sectional view of the stylus of  FIG. 11 , with the piezoelectric device in an actuated state, according to some embodiments of the subject technology. 
         FIG. 14  illustrates a perspective view of a guidetube, according to some embodiments of the subject technology. 
         FIG. 15  illustrates a front sectional view of a stylus that includes the guidetube of  FIG. 14 , according to some embodiments of the subject technology. 
         FIG. 16  illustrates a side sectional view of the stylus of  FIG. 15 , with a piezoelectric device in a resting state, according to some embodiments of the subject technology. 
         FIG. 17  illustrates a side sectional view of the stylus of  FIG. 15 , with the piezoelectric device in an actuated state, according to some embodiments of the subject technology. 
         FIG. 18  illustrates a side sectional view of the stylus of  FIG. 15 , with the piezoelectric device in a deformed state, according to some embodiments of the subject technology. 
         FIG. 19  illustrates a perspective view of a guidetube, according to some embodiments of the subject technology. 
         FIG. 20  illustrates a front sectional view of a stylus that includes the guidetube of  FIG. 19 , according to some embodiments of the subject technology. 
         FIG. 21  illustrates a front sectional view of a stylus, according to some embodiments of the subject technology. 
         FIG. 22  illustrates a side sectional view of the stylus of  FIG. 21 , with a piezoelectric device in a resting state, according to some embodiments of the subject technology. 
         FIG. 23  illustrates a side sectional view of the stylus of  FIG. 21 , with the piezoelectric device in an actuated state, according to some embodiments of the subject technology. 
         FIG. 24  illustrates a side sectional view of a stylus, with first and second piezoelectric devices in resting states, according to some embodiments of the subject technology. 
         FIG. 25  illustrates a side sectional view of the stylus of  FIG. 24 , with the first piezoelectric device in a deformed state, according to some embodiments of the subject technology. 
         FIG. 26  illustrates a side sectional view of the stylus of  FIG. 24 , with the second piezoelectric device in a deformed state, according to some embodiments of the subject technology. 
         FIG. 27  illustrates a front sectional view of a stylus, according to some embodiments of the subject technology. 
         FIG. 28  illustrates a side sectional view of the stylus of  FIG. 27 , with a piezoelectric device in a resting state, according to some embodiments of the subject technology. 
         FIG. 29  illustrates a side sectional view of the stylus of  FIG. 27 , with the piezoelectric device in an actuated state, according to some embodiments of the subject technology. 
         FIG. 30  illustrates a front sectional view of a stylus, according to some embodiments of the subject technology. 
         FIG. 31  illustrates a side sectional view of the stylus of  FIG. 30 , according to some embodiments of the subject technology. 
         FIG. 32  illustrates a front sectional view of a stylus, according to some embodiments of the subject technology. 
         FIG. 33  illustrates a side view of the stylus of  FIG. 32 , according to some embodiments of the subject technology. 
         FIG. 34  illustrates a front sectional view of a stylus, according to some embodiments of the subject technology. 
         FIG. 35  illustrates a side sectional view of the stylus of  FIG. 34 , according to some embodiments of the subject technology. 
         FIG. 36  illustrates a front sectional view of a stylus, according to some embodiments of the subject technology. 
         FIG. 37  illustrates a side sectional view of the stylus of  FIG. 36 , according to some embodiments of the subject technology. 
         FIG. 38  illustrates a flow chart of an example process for providing haptic feedback, according to some embodiments of the subject technology. 
         FIG. 39  illustrates a flow chart of an example process for detecting a user input, according to some embodiments of the subject technology. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology may be practiced. The appended drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. However, it will be clear and apparent to those skilled in the art that the subject technology is not limited to the specific details set forth herein and may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. 
     Some electronic devices that include a display surface and/or a touch panel receive tactile input from a user and also provide haptic feedback to a user. For example, one or more vibration devices located under a touch panel of an electronic device can provide haptic feedback to a user by way of vibrations when the user is touching the touch screen. Such vibrations can be utilized to convey a variety of different information to a user, such as information regarding one or more touch inputs that a user has provided, alerts, or status of the electronic device or one or more applications executing thereupon. 
     Haptic feedback provided via devices with a display surface and/or a touch panel may not convey information adequately to a user when a stylus or other touch-based input device is utilized. In such a case, the user may not be directly touching the surface of the device that provides haptic feedback. As such, the user may not perceive the haptic feedback provided on the surface. Additionally, some existing styluses or other touch-based input devices may provide haptic feedback across an entirety of the device or at a location other than the user&#39;s natural grip location. Such configurations may require greater power consumption and larger haptic feedback components than would be required with components for providing haptic feedback locally at the location of the user&#39;s grip. 
     Furthermore, while the user is holding a stylus or other touch-based input device, the user may be limited to the input options provided thereby. Accordingly, additional input capabilities that are integrated into the input device would provide the user with expanded input capabilities without the need to simultaneously operate additional input devices. Some existing styluses or other touch-based input devices may require a user to operate input components that are at a location other than the user&#39;s natural grip location, thereby requiring that the user adjust the grip to provide the desired input. 
     In accordance with embodiments disclosed herein, improved touch-based input devices can receive tactile input from a user and can also provide haptic feedback to the user. Both the tactile input functions and the haptic feedback functions can be performed by one or more piezoelectric devices that are integrated into the input device. A piezoelectric device can be integrated into an input device in a low profile form that is more compact than many existing haptic feedback components, such as vibration motors. Haptic feedback can be focused to the user&#39;s natural grip location for more direct and efficient transmission. A piezoelectric device can also effectively sense user input passively to consume less power than many existing sensing components, such as strain gauges. Furthermore, a piezoelectric device can effectively detect a sudden tactile input from a user and disregard sustained tactile inputs that are provided while the user simply holds the input device at the user&#39;s natural grip location. 
     A touch-based input device in accordance with embodiments disclosed herein can include any device that is held, worn, or contacted by a user for providing input and/or receiving feedback. The touch-based input device can be used alone or in conjunction with another device. For example,  FIG. 1  illustrates a system  1  including a stylus  100  and an external device  90  having a surface  50 , according to some embodiments of the subject technology. The stylus  100  can be held by a user  10  and operate as a touch-based input device for use with the external device  90 . The surface  50  can include a display surface and/or a touch panel for interacting with the stylus  100  when contacted thereby. For example, the stylus  100  can include a tip  190  for contacting the surface  50 . Such contact can be detected by the external device  90  and/or the stylus  100 . For example, the stylus  100  can include one or more sensors that detect when the tip  190  contacts the surface  50 . Such sensors can include one or more contact sensors, capacitive sensors, touch sensors, cameras, piezoelectric sensors, pressure sensors, photodiodes, and/or other sensors operable to detect contact with the surface  50 . 
     While some embodiments of touch-based input devices disclosed herein relate to styluses, it will be appreciated that the subject technology can encompass and be applied to other input devices. For example, an input device in accordance with embodiments disclosed herein can include a phone, a tablet computing device, a mobile computing device, a watch, a laptop computing device, a mouse, a game controller, a remote control, a digital media player, and/or any other electronic device. Further, the external device can be any device that interacts with a touch-based input device. For example, an external device in accordance with embodiments disclosed herein can include a tablet, a phone, a laptop computing device, a desktop computing device, a wearable device, a mobile computing device, a tablet computing device, a display, a television, a phone, a digital media player, and/or any other electronic device. 
     The stylus  100  can support handling and operation by a user. In particular, the stylus  100  can receive inputs from a user at a location of the user&#39;s grip and provide haptic feedback at the location of the user&#39;s grip.  FIG. 2  illustrates a stylus  100 , according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIG. 2 , the stylus  100  can include a housing  110  that provides an outermost cover along at least a portion of the length of the stylus  100 . A user can grip the stylus  100  at a user grip region  104  during use of the stylus  100 . The user grip region  104  can be located at a natural grip location, so that the user can provide inputs and receive haptic feedback at the same location that is grasped during normal use of the stylus  100 . For example, the user grip region  104  can be located an outer surface  112  of the housing  110 . The user grip region  104  can be near the tip  190  of the stylus  100 . For example, the location of the user grip region  104  can be a distance from the tip  190  that is less than a half, a third, or a quarter of the total length of the stylus  100 . At the user grip region  104 , components of the stylus  100  can be positioned to provide haptic feedback to the user and/or receive tactile input from the user. For example, the user grip region  104  can be a portion of the housing  110 . Alternatively or in combination, the user grip region  104  can include an input component  102  set within the housing  110 , such as a button, switch, knob, lever, and/or another input component  102 . According to some embodiments, a marker can be provided on the outer surface  112  as an indicator for the location of the user grip region  104 . The marker can be flush with neighboring portions of the outer surface  112 , such that it can be seen but provide the same tactile features as other portions of the housing  110 . Alternatively or in combination, the marker can provide a protrusion, recess, or texture that provides surface features that are different from adjacent portions of the housing  110 . 
     The stylus  100  can provide haptic feedback to the user at the user grip region  104  and/or receive tactile input from the user at the user grip region  104  with a piezoelectric device  150 .  FIGS. 3 and 4  illustrate front and side sectional views of the stylus  100 , according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIGS. 3 and 4 , a piezoelectric device  150  can be coupled to the housing  110 . The piezoelectric device  150 , such as a piezo beam, strip, or disk, can be coupled directly to the inner surface  114  of the housing  110  or via an intervening structure that connects to the housing  110 . The inner surface  114  of the housing  110  can be flat at the location of the piezoelectric device  150  to facilitate coupling and securement of the piezoelectric device  150 . The outer surface  112  of the housing  110  can also be flat at the location of the piezoelectric device  150  as an indicator for guiding the user to a grip location. 
     Forces can be transmitted between the piezoelectric device  150  and the user grip region  104  at the outer surface  112  of the housing  110 . The user grip region  104  of the housing  110  can be deformable at least at the location of the piezoelectric device  150  in response to a force applied to the outer surface  112  or the inner surface  114 . At other regions of the housing  110 , rigidity of the housing  110  can be greater or supplemented by additional structure. For example, a guidetube  120  can be provided within a space encompassed by the housing  110 . The guidetube  120  can be coupled to the housing  110  with an adhesive layer  122 . The guidetube  120  can provide an aperture extending therethrough to facilitate direct coupling of the piezoelectric device  150  to the inner surface  114  of the housing  110 . The guidetube  120  can be more rigid than the housing  110 . According to some embodiments, the housing  110 , or a portion thereof, can be of a plastic (e.g., acrylonitrile butadiene styrene (“ABS”)) or elastic material, and the guidetube  120 , or a portion thereof, can be of a metallic material. 
     The piezoelectric device  150  can be of a material with piezoelectric properties. Exemplary materials include, for example, polymers such as polyvinylidene difluoride (“PVDF”) and poly-L-lactide (“PLLA”). Other materials include ceramics (e.g., barium titanate, lead zirconate titanate (“PZT”), potassium niobate, sodium tungstate, zinc oxide), natural crystals (e.g., berlinite, cane sugar, quartz, Rochelle salt, topaz, and/or a tourmaline group mineral), and synthetic crystals (e.g., gallium orthophosphate and/or langasite). The surface area of the piezoelectric device  150  can be, for example, 10 square millimeters, 10 square micrometers, 10 square nanometers, or any other size that provides the functions described herein. The piezoelectric device  150  can have a shape that is rectangular, circular, ovular, triangular, elongated, or combinations thereof. 
     The piezoelectric device  150  can provide haptic feedback to a user. According to some embodiments, the haptic feedback can confirm that a user selection has been received by the external device  90 . According to some embodiments, the haptic feedback can inform the user regarding status or operation of the external device  90 . According to some embodiments, the haptic feedback can render texture sensations to simulate drawing on a textured surface with the stylus  100 . 
     Referring now to  FIG. 5 , with continued reference to  FIGS. 3 and 4 , illustrated is a view of the piezoelectric device  150  in an actuated state, according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIG. 5 , the piezoelectric device  150  provides a force to the user grip region  104  of the housing  110  when an electric voltage is applied to the piezoelectric device  150 . Opposing sides of the piezoelectric device  150  can be connected to electrodes  152  and  154  that connect to positive and negative terminals of a voltage source. When a sufficient voltage is applied across the piezoelectric device  150 , it actuates (e.g., deforms, expands, contracts, or flexes). The piezoelectric device  150  can be made to actuate in any direction. The amount of voltage required to actuate the piezoelectric device  150  may vary and may depend on the type of material used to manufacture the piezoelectric device  150 . When no voltage is supplied by the voltage source, or when the voltage across the piezoelectric device  150  is less than the threshold amount of voltage required to actuate the piezoelectric device  150 , the piezoelectric device  150  can return to its unactuated or resting state. The magnitude of expansion or contraction of the piezoelectric device  150  can be determined by the level or amount of voltage across the piezoelectric device  150 , with a larger amount of voltage corresponding to a higher magnitude of expansion or contraction. Additionally, the polarity of the voltage across the piezoelectric device  150  may determine whether the piezoelectric device  150  contracts or expands. 
     According to some embodiments, the piezoelectric device  150  can be made to vibrate by applying a control signal to the piezoelectric device  150 . The control signal may be a wave having a predetermined amplitude and/or frequency. When the control signal is applied, the piezoelectric device  150  may vibrate at the frequency of the control signal. The frequency can be in a range between 10 Hz and 5,000 Hz, 50 Hz and 1,000 Hz, or 100 Hz and 500 Hz. The frequency of the control signal may be adjusted to alter the rate of expansion and contraction of the piezoelectric device  150  if a certain vibration is desired. The amplitude of the control signal may be correlated to the magnitude of expansion or contraction of the piezoelectric device  150 , and may be adjusted to alter the intensity of the vibration. The voltage can be in a range of between 0.1 and 4.4 V, 1.1 V and 3.3 V, or can be about 2.2 V. 
     The piezoelectric device  150  can receive and detect tactile input from a user. According to some embodiments, the user input can indicate a selection made by the user and transmitted to the external device  90 . According to some embodiments, the user input can indicate that the external device  90  is to perform a corresponding action in response to subsequent inputs from the stylus  100 . For example, the stylus  100  can be used to indicate markings when used on a surface of the external device  90 , and the user input can indicate a selection of marking characteristics, such as shape, thickness, and color. According to some embodiments, the user input can select or alter a setting of the external device  90 , such as a selection between markings (e.g., drawing mode) or erasing existing markings (e.g., eraser mode). 
     Referring now to  FIG. 6 , with continued reference to  FIGS. 2 and 3 , illustrated is a view of the piezoelectric device  150  in a deformed state, according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIG. 6 , the piezoelectric device  150  produces an electric voltage when an input force is applied to an outer surface  112  of the housing  110  and transmitted to the piezoelectric device  150 . 
     When the piezoelectric device  150  deforms, expands, contracts, or flexes based on a tactile input from a user  10 , a voltage is produced across the piezoelectric device  150 . The voltage can be detected and measured via the electrodes  152  and  154  connected to opposing sides of the piezoelectric device  150 . Voltages can be produced based on deformation in one or more axes. The amount of deformation can generate a corresponding amount of voltage. The magnitude of the resulting voltage can be used to determine the force applied by the user  10 . When no deformation is occurring, the voltage can decay. Unlike traditional strain gauge sensors, no external voltage need be applied to the piezoelectric device  150  to detect tactile inputs. Rather, the piezoelectric device  150  can passively remain in a rest state until a force is applied, whereupon a detectable voltage is produced by virtue of the piezoelectric properties of the piezoelectric device  150 . 
     According to some embodiments, the stylus  100  can include one or more piezoelectric devices  150 . Multiple piezoelectric devices  150  can be positioned within the stylus  100  at the same or different radial, circumferential, and/or longitudinal positions. The functions of providing haptic feedback to a user and detecting tactile input from a user can be performed by the same or different piezoelectric devices  150 . Where these functions are provided by the same piezoelectric device  150 , the haptic feedback function can be suspended while the piezoelectric device  150  is sensing a tactile input above a certain threshold. Where these functions are provided by the same piezoelectric device  150 , the sensing function can be suspended while the piezoelectric device  150  is providing haptic feedback. Alternatively or in combination, the sensing function can be performed while the piezoelectric device  150  is providing haptic feedback, for example, by detecting a voltage across the piezoelectric device  150  and compensating for a known or expected offset due to performance of the haptic feedback function. 
     The voltage produced by the piezoelectric device  150  gradually decays during application of sustained forces, such that gradually increasing forces tend to produce less voltage than a more abrupt force that achieves the same peak magnitude in less time. Referring now to  FIGS. 7  and  8 , illustrated are graphs comparing forces applied to a piezoelectric device and output voltages of the piezoelectric device across a span of time, according to some embodiments of the subject technology.  FIG. 7  illustrates the results of a user-applied force that is typical of a user&#39;s normal grip during use of the stylus  100 . As illustrated in  FIG. 7 , the user-applied force gradually increases over time. However, the voltage initially increases to a peak and subsequently decays despite the increasing force. Likewise, a sustained or constant user-applied force would produce an initial voltage that would eventually decay entirely. In contrast,  FIG. 8  illustrates the results of a sudden user-applied force that is typical of a user&#39;s intentional input (e.g., tap, press, squeeze). As illustrated in  FIG. 8 , the user-applied force suddenly increases and subsequently decreases, thereby producing a more distinct force peak and a greater maximum voltage. As can be seen from these graphs, the voltage approximates the rate of change of the force more closely than it approximates the actual magnitude of the force. This feature of the piezoelectric device advantageously facilitates discernment between sustained forces resulting from a user&#39;s grip and a sudden force provided by the user. The system can be programmed to distinguish between gradual forces typical of a user&#39;s normal grip and sudden forces typical of a user-applied input by setting a threshold voltage. For example, the threshold voltage can be greater than a peak voltage such as that illustrated in  FIG. 7  and less than a peak voltage such as that illustrated in  FIG. 8 . Based on these principles, a stylus and operating parameters can be calibrated according to desired outcomes. 
     The stylus  100  can be provided with components that facilitate the operation thereof, including use with an external device  90 .  FIG. 9  illustrates various components of the stylus  100 , according to some embodiments of the subject technology. 
     According to some embodiments, the stylus  100  can include a tip sensor  192  at a tip  190  of the stylus  100  for sensing when the tip  190  is contacting a surface, such as the surface  50  of the external device  90 . The tip sensor  192  can include one or more contact sensors, capacitive sensors, touch sensors, cameras, piezoelectric sensors, pressure sensors, photodiodes, and/or other sensors. 
     According to some embodiments, the stylus  100  can include a controller  106  and a non-transitory storage media  162 . The non-transitory storage media  162  can include, for example, a magnetic storage medium, optical storage medium, magneto-optical storage medium, read-only memory, random access memory, erasable programmable memory, flash memory, or combinations thereof. According to some embodiments, the controller  106  can execute one or more instructions stored in the non-transitory storage medium  162  to perform one or more functions. For example, the non-transitory storage medium  162  can store one or more haptic profiles that the touch implement may utilize to simulate one or more textures. In some cases, the stylus  100  may retrieve a specific haptic profile utilizing one or more references and/or other codes detected from a surface utilizing the tip sensor  192  and/or received from an electronic device associated with the surface. 
     According to some embodiments, the stylus  100  can include a communication component  166  for communicating with the external device  90  and/or another device. The communication component  166  can include one or more wired or wireless components, WiFi components, near field communication components, Bluetooth components, and/or other communication components. The communication component  166  can include one or more transmission elements, such as one or more antennas. Alternatively or in combination, the communication component  166  can include an interface for a wired connection to the external device  90  and/or another device. 
     According to some embodiments, the stylus  100  can include a power source  164 , such as one or more batteries and/or power management units. The stylus  100  can include components for charging the power source  164 . 
     According to some embodiments, the stylus  100  can include other components including, for example, orientation detectors, gyroscopes, accelerometers, biometric readers, displays, sensors, switches (e.g., dome switches), buttons, voice coils, and/or other components. 
     A piezoelectric device can be supported on a portion of a guidetube within a housing.  FIG. 10  illustrates a guidetube  220  of a stylus  200 , according to some embodiments of the subject technology. The stylus  200  can be similar in some respects to the stylus  100  of  FIGS. 1, 2, and 9  and therefore can be best understood with reference thereto. According to some embodiments, for example as illustrated in  FIG. 10 , the guidetube  220  includes a main body  234  and an extension arm  230  that extends from different portions of the main body  234 . The extension arm  230  is separated from neighboring portions of the main body  234  by at least one gap  232 . According to some embodiments, the extension arm  230  extends longitudinally alongside a pair of longitudinal gaps  232  to form a bridge between opposing portions of the main body  234 . 
     Referring now to  FIGS. 11 and 12 , with continued reference to  FIG. 10 , illustrated are front and side sectional views of the stylus  200 , according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIGS. 11 and 12 , the guidetube  220  can be provided within a space encompassed by the housing  210 . The guidetube  220  can be coupled to the housing  210  with an adhesive layer  222 . A piezoelectric device  250  can be disposed between ends of the extension arm  230  that connect to the main body  234 , such that the piezoelectric device  250  is disposed away from portions of the extension arm  230  that connect to the main body  234 . According to some embodiments, the outer surface  212  of the housing  210  and the inner surface  214  of the housing  210  can be curved. The extension arm  230  of the guidetube  220  can provide one or more flat surfaces for coupling to the piezoelectric device  250 . According to some embodiments, the stylus  200  includes a force concentrator  240  between the housing  210  and the extension arm  230  of the guidetube  220 . The force concentrator  240  can have a surface area that is smaller than a surface area of the piezoelectric device  250 , to transmit forces between the housing  210  and the guidetube  220 . Forces transmitted by the force concentrator are focused in a smaller area than would be by the piezoelectric device  250  alone. 
     The piezoelectric device  250  can provide haptic feedback to a user. Referring now to  FIG. 13 , with continued reference to  FIGS. 11 and 12 , illustrated is a view of the piezoelectric device  250  in an actuated state, according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIG. 13 , the piezoelectric device  250  provides a force to the housing  210  when an electric voltage is applied to the piezoelectric device  250 . The force can be transmitted via the extension arm  230  of the guidetube  220  and the force concentrator  240 . The gaps  232  surrounding the extension arm  230  provide flexibility to the extension arm  230  to facilitate deformation, expansion, contraction, or flexion thereof. According to some embodiments, the piezoelectric device  250  can also detect tactile input from a user. For example, the piezoelectric device  250  can produce an electric voltage when an input force is applied to an outer surface  212  of the housing  210  and transmitted to the piezoelectric device  250  via the force concentrator  240  and the extension arm  230  of the guidetube  220 . 
     One or more piezoelectric devices can be supported on portions of a guidetube within a housing.  FIG. 14  illustrates a guidetube  320  of a stylus  300 , according to some embodiments of the subject technology. The stylus  300  can be similar in some respects to the stylus  100  of  FIGS. 1, 2, and 9  and therefore can be best understood with reference thereto. According to some embodiments, for example as illustrated in  FIG. 14 , the guidetube  320  includes a main body  334  and an extension arm  330  that extends from a portion of the main body  334 . The extension arm  330  extends from the main body  334  at a single region of attachment thereto. The extension arm  330  is surrounded on multiple sides by the gap  332 , such that the extension arm  330  can bend and flex at the junction  336  between the extension arm  330  and the main body  334 . 
     Referring now to  FIGS. 15 and 16 , with continued reference to  FIG. 10 , illustrated are front and side sectional views of the stylus  300 , according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIGS. 15 and 16 , the guidetube  320  can be provided within a space encompassed by the housing  310 . The guidetube  320  can be coupled to the housing  310  with an adhesive layer  322 . A first piezoelectric device  350  can be disposed away from the junction  336  between the extension arm  330  and the main body  334 . A second piezoelectric device  352  can be disposed at the junction  336  between the extension arm  330  and the main body  334 . According to some embodiments, the stylus  300  includes a force concentrator  340  between the housing  310  and the extension arm  330  of the guidetube  320 . 
     One or both of the piezoelectric devices  350  and  352  can provide haptic feedback to a user. Referring now to  FIG. 17 , with continued reference to  FIGS. 15 and 16 , illustrated is a view of the piezoelectric device  350  in an actuated state, according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIG. 17 , the first piezoelectric device  350  provides a force to the housing  310  when an electric voltage is applied to the piezoelectric device  350 . In particular, the gap  332  allows the extension arm  330  to pivot about the junction  336  so that an end region of the extension arm  330  moves against the housing  310  and transmits forces to the housing  310 . The force can be transmitted via the extension arm  330  of the guidetube  320  and the force concentrator  340 . 
     One or both of the piezoelectric devices  350  and  352  can detect tactile input from a user. Referring now to  FIG. 18 , with continued reference to  FIGS. 15 and 16 , illustrated is a view of the second piezoelectric device  352  in a deformed state, according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIG. 17 , the second piezoelectric device  352  can produce an electric voltage when an input force is applied to an outer surface  312  of the housing  310  and transmitted to the second piezoelectric device  352  via the force concentrator  340  and the extension arm  330  of the guidetube  320 . In particular, as the extension arm  330  pivots about the junction  336 , the second piezoelectric device  352  is deformed due to its position spanning the junction  336 . 
     Multiple piezoelectric devices can be positioned within a stylus, for example, at the different radial, circumferential, and/or longitudinal positions.  FIG. 19  illustrates a guidetube  420  of a stylus  400 , according to some embodiments of the subject technology. The stylus  400  can be similar in some respects to the stylus  100  of  FIGS. 1, 2, and 9  and therefore can be best understood with reference thereto. According to some embodiments, for example as illustrated in  FIG. 19 , the guidetube  420  includes a main body  434  and extension arms  430  that each extend from different portions of the main body  434 . 
     Referring now to  FIG. 20 , with continued reference to  FIG. 19 , illustrated is a front sectional view of the stylus  400 , according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIG. 20 , for example as illustrated in  FIG. 20 , the guidetube  420  can be provided within a space encompassed by the housing  410 . Multiple piezoelectric devices  450  are disposed along inner surfaces  414  of corresponding extension arms  430  of the guidetube  420 . As illustrated in  FIG. 20 , the piezoelectric devices  450  can be circumferentially distributed such that each piezoelectric device  450  has a circumferential position that is different from other piezoelectric devices  450 . The piezoelectric devices  450  can be equally distributed, such that the distance between circumferentially adjacent pairs of piezoelectric devices  450  is the same. Alternatively or in combination, the piezoelectric devices  450  can have an uneven distribution. Any number of piezoelectric devices  450  can be provided. For example, the stylus  400  can include 1, 2, 3, 4, 5, 6, 7, 8, 9, or more than 9 piezoelectric devices  450 . At least some of the piezoelectric devices  450  can have the same or different circumferential positions (e.g., about a perimeter of the stylus). At least some of the piezoelectric devices  450  can have the same or different longitudinal positions (e.g., relative to the tip). At least some of the piezoelectric devices  450  can have the same or different radial positions (e.g., relative to a central axis). 
     An annular piezoelectric device can extend along an entire perimeter of an inner surface of a housing.  FIGS. 21 and 22  illustrate front and side sectional views of a stylus  500 , according to some embodiments of the subject technology. The stylus  500  can be similar in some respects to the stylus  100  of  FIGS. 1, 2, and 9  and therefore can be best understood with reference thereto. According to some embodiments, for example as illustrated in  FIGS. 21 and 22 , the stylus  500  includes a housing  510  with an outer surface  512  and an inner surface  514 . According to some embodiments, a guidetube  520  can be provided within a space encompassed by the housing  510 . The guidetube  520  can be coupled to the housing  510  with an adhesive layer  522 . A piezoelectric device  550  can be disposed radially between the guidetube  520  and the housing  510 . The piezoelectric device  550  can form an annular ring that extends along an entire perimeter of the inner surface  514  of the housing  510 . Alternatively or in combination, the piezoelectric device  550  can extend along a portion of a perimeter of the inner surface  514 . The piezoelectric device  550  and the guidetube  520  can be radially separated by an annular gap  530 , so the piezoelectric device  550  is permitted to deform somewhat without contacting the guidetube  520 . 
     The piezoelectric device  550  can provide haptic feedback to a user. Referring now to  FIG. 23 , with continued reference to  FIGS. 21 and 22 , illustrated is a view of the piezoelectric device  550  in an actuated state, according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIG. 23 , the piezoelectric device  550  provides a force to the housing  510  when an electric voltage is applied to the piezoelectric device  550 . According to some embodiments, the piezoelectric device  550  can also detect tactile input from a user. For example, the piezoelectric device  550  can produce an electric voltage when an input force is applied to an outer surface  512  of the housing  510  and transmitted to the piezoelectric device  550 . 
     Multiple piezoelectric devices can be used in concert to detect particular user inputs.  FIG. 24  illustrates a side sectional view of a stylus  600 , according to some embodiments of the subject technology. The stylus  600  can be similar in some respects to the stylus  100  of  FIGS. 1 ,  2 , and  9  and therefore can be best understood with reference thereto. According to some embodiments, for example as illustrated in  FIG. 24 , the stylus  600  can include multiple piezoelectric devices  650  and  652 . The piezoelectric devices  650  and  652  can be coupled to an inner surface  612  of a housing  610 . The piezoelectric devices  650  and  652  can be arranged along a line or other path. Any number of piezoelectric devices can be provided along a path. For example, the stylus  600  can include 2, 3, 4, 5, 6, 7, 8, 9, or more than 9 piezoelectric devices along a path. The stylus  600  can also include a guidetube  620  provided within a space encompassed by the housing  610 . The guidetube  620  can be coupled to the housing  610  with an adhesive layer  622 . 
     Referring now to  FIGS. 25 and 26 , with continued reference to  FIG. 24 , illustrated are various views of the sensing states of the stylus  600 , according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIG. 25 , as a user  10  applies a force to the first piezoelectric device  650 , the stylus  600  can detect the resulting voltage that is induced in the first piezoelectric device  650 . As illustrated in  FIG. 26 , the user  10  can subsequently apply a force to the second piezoelectric device  652 , and the stylus  600  can detect the resulting voltage that is induced in the second piezoelectric device  652 . The sequence of forces and induced voltages within a span of time can be interpreted by the stylus  600  as a user&#39;s motion gesture in a particular direction (e.g., in a direction along a line or path defined by the arrangement of the piezoelectric devices  650  and  652 ). For example, the sequence of (1) a detected voltage in the first piezoelectric device  650  and then (2) a detected voltage and the second piezoelectric device  652  can be interpreted as a user motion gesture in a first direction. The sequence of (1) a detected voltage and the second piezoelectric device  652  and then (2) a detected voltage in the first piezoelectric device  650  can be interpreted as a user motion gesture in a second direction, opposite the first direction. Detected user motion gestures can be correlated with preprogrammed functions to be performed by the stylus  600  and/or an external device upon detection of the user motion gestures. 
     A piezoelectric device can extend between opposing sides of a housing.  FIGS. 27 and 28  illustrate front and side sectional views of a stylus  700 , according to some embodiments of the subject technology. The stylus  700  can be similar in some respects to the stylus  100  of  FIGS. 1, 2, and 9  and therefore can be best understood with reference thereto. According to some embodiments, for example as illustrated in  FIGS. 27 and 28 , the stylus  700  can include a piezoelectric device  750 , such as a disk, that extends between opposing sides of a housing  710 . The piezoelectric device  750  can extend, for example, through a central axis of the housing  710 . The housing  710  can include an outer surface  712  and an inner surface  714 . The stylus  700  can also include a guidetube  720  provided within a space encompassed by the housing  710 . The guidetube  720  can be coupled to the housing  710  with an adhesive layer  722 . The piezoelectric device  750  can extend through opposing portions of the guidetube  720  to contact the inner surface  714  on opposing sides of the housing  710 . The piezoelectric device  750  can include one or more extensions  752  that extend radially from a central portion of the piezoelectric device  750  to extend through gaps in the guidetube  720 . Any number of extension  752  can be provided. For example, the piezoelectric device  750  can include can include 1, 2, 3, 4, 5, 6, 7, 8, 9, or more than 9 extensions  752 . The piezoelectric device  750  can be stabilized between longitudinally opposite portions of the guidetube  720 , such that longitudinal mobility of the piezoelectric device  750  is limited by the guidetube  720 . 
     The piezoelectric device  750  can provide haptic feedback to a user. Referring now to  FIGS. 28 and 29 , with continued reference to  FIG. 27 , illustrated are various views of the haptic feedback states of the stylus  700 , according to some embodiments of the subject technology. According to some embodiments, for example as illustrated in  FIG. 27 , the piezoelectric device  750  (e.g., the extensions  752 ) provides a force to the housing  710  when an electric voltage is applied to the piezoelectric device  750 . According to some embodiments, the piezoelectric device  750  can also detect tactile input from a user. For example, the piezoelectric device  750  can produce an electric voltage when an input force is applied to an outer surface  712  of the housing  710  and transmitted to the piezoelectric device  750  (e.g., via the extensions  752 ). 
     According to some embodiments, one or more features of the stylus  100 , the stylus  200 , the stylus  300 , the stylus  400 , the stylus  500 , the stylus  600 , and/or the stylus  700  can be combined in a single device. For example, an input device of the subject technology can include one or more piezoelectric devices  150 , one or more piezoelectric devices  250 , one or more first piezoelectric devices  350 , one or more second piezoelectric devices  352 , one or more piezoelectric devices  450 , one or more piezoelectric devices  550 , one or more first piezoelectric devices  650 , one or more second piezoelectric devices  652 , and/or one or more piezoelectric devices  750 . According to some embodiments, any one or more of the piezoelectric devices can be used for providing haptic feedback to a user. According to some embodiments, any one or more of the piezoelectric devices can be used for detecting tactile input from a user. 
     A piezoelectric device can follow a helical path along a portion of a stylus. The helical path can allow the piezoelectric device to provide tactile input detection and/or haptic feedback at a variety of circumferential locations across a given length of the stylus.  FIGS. 30 and 31  illustrate front and side sectional views of a stylus  800 , according to some embodiments of the subject technology. The stylus  800  can be similar in some respects to the stylus  100  of  FIGS. 1, 2, and 9  and therefore can be best understood with reference thereto. According to some embodiments, for example as illustrated in  FIGS. 30 and 31 , the stylus  800  includes a housing  810  and a guidetube  820 , which can be provided within a space encompassed by the housing  810 . A piezoelectric device  850  can be disposed radially between portions of the guidetube  820  and the housing  810 . Layers of the housing  810 , the guidetube  820 , and the piezoelectric device  850  can be coupled together with an adhesive  822 . The piezoelectric device  850  can form a helix that extends between the guidetube  820  and the housing  810 . The helical shape of the piezoelectric device  850  can extend circumferentially at least one turn within the housing  810 . The piezoelectric device  850  can be directly coupled to the guidetube  820  and/or the housing  810 . Alternatively or in combination, the piezoelectric device  850  can be directly coupled to only one of the guidetube  820  and the housing  810  and be separated from the other by a radial gap. Multiple piezoelectric devices  850  can be used in concert to provide haptic feedback at various longitudinal locations and/or detect particular user inputs. For example, multiple piezoelectric devices  850  can be arranged at various longitudinal locations in a manner similar to the arrangement of the stylus  600 , as shown in  FIGS. 24-26 . 
     A piezoelectric device can be provided on an outer surface of a housing of a stylus. The position of the piezoelectric device on the outer surface can provide tactile input detection and/or haptic feedback immediately adjacent to the grip of a user.  FIGS. 32 and 33  illustrate front and side sectional views of a stylus  900 , according to some embodiments of the subject technology. The stylus  900  can be similar in some respects to the stylus  100  of  FIGS. 1, 2, and 9  and therefore can be best understood with reference thereto. According to some embodiments, for example as illustrated in  FIGS. 32 and 33 , the stylus  900  includes a housing  910  and a piezoelectric device  950  disposed on the housing  910 . The housing  910  and the piezoelectric device  950  can be coupled together with an adhesive  922 . The piezoelectric device  950  can form a helix or another shape, such as an annular ring, a longitudinally extending segment, or another shape described herein. Multiple piezoelectric devices  950  can be used in concert to provide haptic feedback at various longitudinal locations and/or detect particular user inputs. For example, multiple piezoelectric devices  950  can be arranged at various longitudinal locations in a manner similar to the arrangement of the stylus  600 , as shown in  FIGS. 24-26 . 
     A piezoelectric device or multiple piezoelectric devices can extend circumferentially within a stylus to provide tactile input detection and/or haptic feedback at a variety of circumferential locations.  FIGS. 34 and 35  illustrate front and side sectional views of a stylus  1000 , according to some embodiments of the subject technology. The stylus  1000  can be similar in some respects to the stylus  100  of  FIGS. 1,2, and 9  and therefore can be best understood with reference thereto. According to some embodiments, for example as illustrated in  FIGS. 34 and 35 , the stylus  1000  includes a housing  1010  and a guidetube  1020 , which can be provided within a space encompassed by the housing  1010 . Piezoelectric devices  1050  can be disposed radially between portions of the guidetube  1020  and the housing  1010 . Layers of the housing  1010 , the guidetube  1020 , and the piezoelectric devices  1050  can be coupled together with an adhesive  1022 . The piezoelectric devices  1050  can form arcs that extend circumferentially between the guidetube  1020  and the housing  1010 . Where multiple piezoelectric devices  1050  are provided, the multiple piezoelectric devices  1050  can be circumferentially adjacent to each other to provide a combined structure. The combined structure extends across all or most of an entire circumference. Alternatively or in combination, a single piezoelectric device  1050  can extend an entire, continuous circumference. Multiple piezoelectric devices  1050  can be used in concert to provide haptic feedback at various longitudinal locations and/or detect particular user inputs. For example, multiple piezoelectric devices  1050  can be arranged at various longitudinal locations in a manner similar to the arrangement of the stylus  600 , as shown in  FIGS. 24-26 . 
     Multiple piezoelectric devices can be distributed about a circumference to provide tactile input detection and/or haptic feedback at selected circumferential locations.  FIGS. 36 and 37  illustrate front and side sectional views of a stylus  1100 , according to some embodiments of the subject technology. The stylus  1100  can be similar in some respects to the stylus  100  of  FIGS. 1 ,  2 , and  9  and therefore can be best understood with reference thereto. According to some embodiments, for example as illustrated in  FIGS. 36 and 37 , the stylus  1100  includes a housing  1110  and a guidetube  1120 , which can be provided within a space encompassed by the housing  1110 . Piezoelectric devices  1150  can be disposed radially between portions of the guidetube  1120  and the housing  1110 . Layers of the housing  1110 , the guidetube  1120 , and the piezoelectric devices  1150  can be coupled together with an adhesive  1122 . The piezoelectric devices  1150  can be distributed at selected circumferential locations between the guidetube  1120  and the housing  1110 . Each circumferentially adjacent pair of piezoelectric devices  1150  can be separated by a circumferential gap (e.g., filled with the adhesive  1122 ). The location of the piezoelectric devices  1150  can be selected to effectively provide adequate tactile input detection and/or haptic feedback without excessive coverage. The reduced size of the piezoelectric devices  1150  can focus activity where it is most effective. For example, the piezoelectric devices  1150  can be arranged to align with a location of a user&#39;s grip. Multiple piezoelectric devices  1150  can be used in concert to provide haptic feedback at various longitudinal locations and/or detect particular user inputs. For example, multiple piezoelectric devices  1150  can be arranged at various longitudinal locations in a manner similar to the arrangement of the stylus  600 , as shown in  FIGS. 24-26 . 
     According to some embodiments, a method  1200  can be employed to manage the haptic feedback that is provided to the user.  FIG. 38  illustrates a flow chart of an example process for providing haptic feedback, according to some embodiments of the subject technology. According to some embodiments, for example as illustrated at block  1202  of  FIG. 38 , a stylus (e.g., input device) can receive an action signal. The action signal can be received from an external device, such as via the communication component  166  of the stylus. For example, an action signal from an external device can include an indication (e.g., confirmation) that a selection has been received by the external device from the user. By further example, an action signal from an external device can include a notification, alert, or alarm managed by the external device. An action signal from an external device can include information regarding operation of the stylus in conjunction with the external device. For example, an action signal from an external device can confirm the occurrence and/or a characteristic of contact between the stylus and the external device, such as when contact is made and the magnitude of force applied. According to some embodiments, the action signal can be received from a component of the stylus, such as a tip sensor, an accelerometer, a gyroscope, or a piezoelectric device of the stylus. An action signal from a component of the stylus can indicate that a user-applied input has been detected. An action signal from a component of the stylus can indicate a position and/or orientation of the stylus. 
     According to some embodiments, for example as illustrated at block  1204  of  FIG. 38 , receipt of the action signal at the stylus can prompt the stylus to determine a corresponding action. Such a determination can be performed, for example, by the controller  160  and/or the storage medium  162  of the stylus. The origin of the action signal and/or a characteristic thereof can be analyzed and compared to preprogrammed actions to be performed by the stylus. Preprogrammed actions can be stored in a storage medium of the stylus. For example, a lookup table can include a record of action signals with associated actions to be performed by the stylus. Action signals can be compared to a threshold to determine whether a corresponding action should be performed. Other factors, such as whether a piezoelectric device of the stylus is receiving an input from a user, can be considered to determine whether a corresponding action should be performed. 
     According to some embodiments, for example as illustrated at block  1206  of  FIG. 38 , the stylus can provide haptic feedback to a user based on the determined action. The haptic feedback can be provided, for example, by the piezoelectric device based on operation of the controller  160 . Upon determining a corresponding action, the stylus (e.g., via the controller  160 ) can operate a piezoelectric device to provide haptic feedback to user. According to some embodiments, the haptic feedback can be provided in accordance with the corresponding action that is determined based on the action signal. For example, the haptic feedback via the stylus can inform the user regarding status or operation of the external device. 
     According to some embodiments, the haptic feedback can enhance operation of the stylus. For example, operation of the piezoelectric device can render texture sensations to simulate drawing on a textured surface with the stylus. Vibrations can be transmitted to the user from the piezoelectric device as the stylus is determined to be moving across a surface of an external device. The force of the contact, the speed of the stylus, the orientation of the stylus, and/or the textured surface to be simulated can be considered to determine the operation of the piezoelectric device. 
     According to some embodiments, a method  1300  can be employed to detect tactile input from a user.  FIG. 39  illustrates a flow chart of an example process for detecting a user input, according to some embodiments of the subject technology. According to some embodiments, for example as illustrated at block  1302  of  FIG. 38 , a voltage can be detected across a piezoelectric device of a stylus (e.g., input device). The voltage can be induced by an input force from a user, for example applied to a housing of the stylus. The voltage can be detected passively, without requiring a power source to detect a change in voltage. According to some embodiments, a magnitude, duration, and/or change of the voltage can be detected. Voltage is across one or more piezoelectric devices can be detected for further analysis. 
     According to some embodiments, for example as illustrated at block  1304  of  FIG. 39 , the voltage across a piezoelectric device can be analyzed to interpret a characteristic of an input force from a user. Such analysis can be performed, for example, by the controller  160  and/or the storage medium  162  of the stylus. According to some embodiments, the characteristic of the input force can include a magnitude, duration, and/or change of the input force. For example, as discussed herein and illustrated in  FIGS. 7 and 8 , characteristics of the input force can be inferred from the resulting voltage across a piezoelectric device. 
     According to some embodiments, the input force can be the sensing function can be performed while the piezoelectric device  150  is providing haptic feedback, for example, by detecting a voltage across the piezoelectric device  150  and compensating for a known or expected offset due to performance of the haptic feedback function. Where sensing and haptic feedback are provided by the same piezoelectric device, the sensing can be performed while the piezoelectric device is providing haptic feedback by detecting a voltage across the piezoelectric device and compensating for a known or expected offset due to performance of the haptic feedback function. 
     According to some embodiments, the stylus can compensate for a known or expected decay of the voltage across the piezoelectric device. As discussed herein, a sustained or constant user-applied force would produce an initial voltage that would eventually decay entirely. The stylus can utilize a charge amplifier to compensate for the decay in voltage or calculate a theoretical voltage based on the known or expected decay during the time span of a user input. 
     According to some embodiments, a characteristic of the input force can be compared to preprogrammed thresholds and/or converted to a value that is transmitted as an input signal. The value can be proportionate to or otherwise based on one or more characteristics of the input force. 
     According to some embodiments, for example as illustrated at block  1306  of  FIG. 39 , and input signal can be transmitted from the stylus based on the input force and analysis thereof. The transmission can be performed, for example, by the communication component  166  based on operation of the controller  160 . The input signal can be transmitted to an external device and/or other components of the stylus. The input signal can include information relating to a characteristic of the input force. For example, the input signal can include a value that represents a magnitude of the input force and/or that the input force exceeds a threshold. 
     According to some embodiments, the stylus and/or an external device can be provided with instructions to perform certain actions upon receipt of the input signal. For example, an external device can interpret receipt of the input signal as a user selection. The subject of the user selection can be further indicated, for example, by contact of the stylus (e.g., the tip of the stylus) on a surface of the external device. 
     According to some embodiments, the external device can record receipt of the input signal and apply a corresponding action in response to subsequent inputs from the stylus. For example, the stylus can be used for drawing or writing by contacting the surface of the external device with the tip of the stylus. Such input can be recorded by the external device with markings, lines, or shapes having a variety of characteristics. For example, the recorded markings can have a certain shape, thickness, and color. When the user operates the piezoelectric device to create an input signal, the external device can interpret the input signal as a command to apply one or more characteristics to markings generated by subsequent input from the stylus. Accordingly, subsequent contact between the tip of the stylus and the surface of the external device can be recorded as markings having the one or more characteristics determined by the input signal. According to some embodiments, the input signal generated by operation of the piezoelectric device can toggle a setting that interprets subsequent inputs as either drawing new markings (e.g., drawing mode) or erasing existing markings (e.g., eraser mode). According to some embodiments, during receipt of an input signal generated by operation of the piezoelectric device, inputs from the tip of the stylus can be interpreted based on the input signal. For example, an input signal that corresponds to a magnitude of a force applied to the piezoelectric device can command the external device to interpret simultaneous inputs from the tip of the stylus with markings that have a thickness proportionate to the magnitude of the force. Drawing with the stylus during application of a force above a threshold or within a higher range can result in thicker markings, and drawing with the stylus during application of a force below the threshold or within a lower range can result in thinner markings. Multiple ranges and thresholds can apply to the detected voltage to provide a range of possible input signals. 
     According to some embodiments, the characteristic of the input force can include a direction, pathway, speed, and/or length of a user motion gesture providing the input force. For example, a stylus can track a user motion gesture across multiple piezoelectric devices and detect input forces applied in sequence to each of the multiple piezoelectric devices. The combined input can be used to detect a direction, pathway, speed, and/or length of the user motion gesture across the multiple piezoelectric devices. The stylus or the external device can interpret the resulting input signal as a command to perform a function in accordance with the characteristic. According to some embodiments, the input signal can change a setting of the external device based on the input signal. For example, the external device can change volume, brightness, display zoom, marking characteristic, or other features of the external device to an extent that is proportionate to the characteristic (e.g., length) of the user motion gesture. For example, applying a user motion gesture in a first direction across the piezoelectric devices can increase a setting value (e.g., volume, marking thickness, etc.) of the external device, and applying a user motion gesture across the piezoelectric devices in a second direction, opposite the first direction, can decrease the setting value of the external device. 
     Various functions described above can be implemented in digital electronic circuitry, in computer software, firmware or hardware. The techniques can be implemented using one or more computer program products. Programmable processors and computers can be included in or packaged as mobile devices. The processes and logic flows can be performed by one or more programmable processors and by one or more programmable logic circuitry. General and special purpose computing devices and storage devices can be interconnected through communication networks. 
     Some implementations include electronic components, such as microprocessors, storage and memory that store computer program instructions in a machine-readable or computer-readable medium (alternatively referred to as computer-readable storage media, machine-readable media, or machine-readable storage media). Some examples of such computer-readable media include RAM, ROM, read-only compact discs (CD-ROM), recordable compact discs (CD-R), rewritable compact discs (CD-RW), read-only digital versatile discs (e.g., DVD-ROM, dual-layer DVD-ROM), a variety of recordable/rewritable DVDs (e.g., DVD-RAM, DVD-RW, DVD+RW, etc.), flash memory (e.g., SD cards, mini-SD cards, micro-SD cards, etc.), magnetic and/or solid state hard drives, ultra density optical discs, any other optical or magnetic media, and floppy disks. The computer-readable media can store a computer program that is executable by at least one processing unit and includes sets of instructions for performing various operations. Examples of computer programs or computer code include machine code, such as is produced by a compiler, and files including higher-level code that are executed by a computer, an electronic component, or a microprocessor using an interpreter. 
     While the above discussion primarily refers to microprocessor or multi-core processors that execute software, some implementations are performed by one or more integrated circuits, such as application specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs). In some implementations, such integrated circuits execute instructions that are stored on the circuit itself. 
     As used in this specification and any claims of this application, the terms “computer”, “processor”, and “memory” all refer to electronic or other technological devices. These terms exclude people or groups of people. For the purposes of the specification, the terms “display” or “displaying” means displaying on an electronic device. As used in this specification and any claims of this application, the terms “computer readable medium” and “computer readable media” are entirely restricted to tangible, physical objects that store information in a form that is readable by a computer. These terms exclude any wireless signals, wired download signals, and any other ephemeral signals. 
     To provide for interaction with a user, implementations of the subject matter described in this specification can be implemented on a computer having a display device as described herein for displaying information to the user and a keyboard and a pointing device, such as a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, such as visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input. 
     Many of the above-described features and applications are implemented as software processes that are specified as a set of instructions recorded on a computer readable storage medium (also referred to as computer readable medium). When these instructions are executed by one or more processing unit(s) (e.g., one or more processors, cores of processors, or other processing units), they cause the processing unit(s) to perform the actions indicated in the instructions. Examples of computer readable media include, but are not limited to, CD-ROMs, flash drives, RAM chips, hard drives, EPROMs, etc. The computer readable media does not include carrier waves and electronic signals passing wirelessly or over wired connections. 
     In this specification, the term “software” is meant to include firmware residing in read-only memory or applications stored in magnetic storage, which can be read into memory for processing by a processor. Also, in some implementations, multiple software aspects of the subject disclosure can be implemented as sub-parts of a larger program while remaining distinct software aspects of the subject disclosure. In some implementations, multiple software aspects can also be implemented as separate programs. Finally, any combination of separate programs that together implement a software aspect described here is within the scope of the subject disclosure. In some implementations, the software programs, when installed to operate on one or more electronic systems, define one or more specific machine implementations that execute and perform the operations of the software programs. 
     A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, declarative or procedural languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, object, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network. 
     It is understood that any specific order or hierarchy of blocks in the processes disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes may be rearranged, or that all illustrated blocks be performed. Some of the blocks may be performed simultaneously. For example, in certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. 
     The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. Headings and subheadings, if any, are used for convenience only and do not limit the subject disclosure. 
     The predicate words “configured to”, “operable to”, and “programmed to” do not imply any particular tangible or intangible modification of a subject, but, rather, are intended to be used interchangeably. For example, a processor configured to monitor and control an operation or a component may also mean the processor being programmed to monitor and control the operation or the processor being operable to monitor and control the operation. Likewise, a processor configured to execute code can be construed as a processor programmed to execute code or operable to execute code 
     A phrase such as an “aspect” does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. A phrase such as an aspect may refer to one or more aspects and vice versa. A phrase such as a “configuration” does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. A disclosure relating to a configuration may apply to all configurations, or one or more configurations. A phrase such as a configuration may refer to one or more configurations and vice versa. 
     The word “example” is used herein to mean “serving as an example or illustration.” Any aspect or design described herein as “example” is not necessarily to be construed as preferred or advantageous over other aspects or design 
     All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.” Furthermore, to the extent that the term “include,” “have,” or the like is used in the description or the claims, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim.

Metadata:
Filing Date: 20170830
Publication Date: 20200218
Grant Date: 20200218
Priority Date: 20160920
Inventors: BERGERON, KATHLEEN A.
LEHMANN, Alex J.
XU, QILIANG
GAO, ZHENG
WANG, PAUL X.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F2203/0383", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/0381", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/03545", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0383", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/03545", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/0381", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0383", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/03545", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0383", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/0381", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/016", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 69528296