Abstract:
Embodiments of the present invention are directed to systems for improved touch screen user-input devices that combine the benefits of active and passive touch screen implementations. According to one or more embodiments of the present invention, a system is provided that includes a user input touch device (such as a stylus) that can be equipped with one or more tips of various sizes and shapes, and a touch screen input surface that is configured to detect each of the various tips. In contrast to prevailing conventional active stylus implementations, this allows touch screen implementations to use styluses with tips that simulate real-world artistic tools that are currently not available in digital arts media. Moreover, data obtained in the input device itself is communicated to the touch screen processor/controller to supplement the input data received in the touch screen device.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation-in-Part of U.S. application Ser. No. 14/250,254, filed Apr. 10, 2014 entitled “Stylus Signaling for Capacitive Touch Screen Panels” to Pedersen et al., which claims benefit of U.S. Provisional Applications No. 61/810,578, filed Apr. 10, 2013 entitled “Methods for Operating a Touch Screen Enabled Device with a Low Cost Stylus” to Huang et al., and U.S. Provisional Application No. 61/810,997, filed Apr. 11, 2013 entitled “Pen Signaling for Capacitive Touch Panels” to Pedersen et al. This application is related to U.S. patent application Ser. No. 14/165,324, filed Jan. 27, 2014 entitled “Stylus Tool with Deformable Tip” to Zerayohannes et al., which is incorporated by reference herein in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    Embodiments of this present invention are directed toward improving user interactions with touch input devices. More specifically, embodiments of the invention are directed to solutions for an improved user experience with touch input devices by enhancing the sensitivity and accuracy of touch input devices. 
       BACKGROUND OF THE INVENTION 
       [0003]    In the field of touch screen devices, there exists a need for writing utensils capable of interacting with touch screens to provide more versatile user input. Typically, these writing utensils have been implemented as styluses (or similar touch input devices), which mimic the shape and feel of traditional writing tools such as pens. Historically, these styluses were implemented as “passive” tools that were compatible with the detection scheme employed by the corresponding touch screen, without inherent processing or communication ability. 
         [0004]    Resistive touch screens were a popular early touch screen implementation, and are still used in many applications. One type of resistive touch screen involves two layers of electrically-resistive lines of electrodes, placed one above the other and spaced slightly apart. The lines of each layer are parallel with respect to the other lines of the same layer, and perpendicular with the lines of the other layer, thus forming a grid or matrix. When pressed by an object (such as a finger or stylus), the two layers come into contact, a contact point is created that causes a disruption to the voltage levels in the layers. The voltage across the touch screen is measured frequently by an array of sensors beneath the second layer, and any deviations in the voltage resulting from the contact between the layers (as pressed together by the input object) are detected. The point at which the object contacted the top layer is then specifically determined in the second layer (via proximity to the closest sensor) and registered as user input. A second type of resistive touch screen applies a uniform voltage gradient to a top layer. When the two layers are pressed together as a result of a contacting object, the underlying layer measures the voltage as a distance along the top layer, and generates a location coordinate along a first axis from the measurement. The voltage gradient is then applied to the bottom layer to determine the location coordinate along the other axis, and the position of the contact point is determined by combining the coordinate information. 
         [0005]    More recently, capacitive sensors have been used increasingly in lieu of traditional resistance-based touch screens, due to their relatively improved sensitivity and accuracy, and reduced size requirements. Even more recently, the detection of multiple touch inputs has been made possible by developments in the underlying touch controllers. Capacitive touch screens operate by maintaining an electrostatic field across the surface of a touch screen using an array of capacitive sensors. When an electrically conductive object (such as a finger or a specialized touch input device) comes into contact with the surface of the screen, the electrostatic field is distorted, resulting in a change in the capacitance at the sensors nearest to the contact point. Mere detection of the input position requires no active components from the input device, and any non-insulated material can be used. 
         [0006]    As the technology of capacitive sensors and corresponding software has developed, the resolution (e.g., sensor density) of the touch screens has been able to increase commensurately, thereby also increasing the sensitivity and accuracy of registered touch inputs as well. This improved functionality has led to the rise of touch screens for new endeavors. Whereas in early implementations touch screens were typically limited to registering activation or user actuation of graphical interface elements such as buttons or virtual keyboard keys, advanced touch screen implementations have been extended to be used for handwriting, digital arts and other more advanced user input, particularly with the use of specialized styluses. 
         [0007]    Conventional touch-screen implemented digital arts typically use a single, narrow-tipped stylus to perform writing and drawing motions on the touch screen. However, these implementations (referred to as passive styluses) present an issue when the user wants to express a different font or stroke size. One popular alternative to passive styluses that has been developed allows the user to increase the width of an input (such as a stroke) proportionally to correspond to a pressure applied to the stylus, by detecting the pressure in the stylus using a pressure sensor, and communicating the pressure data to the touch screen device. These implementations—with the ability to determine additional user input data and to communicate such data—are known as active styluses. However, while suitable for expressing different stroke or font widths, not only do active styluses require additional sensor, circuit, and communication components to detect and communicate such data, the very act of applying pressure proportionally to increase input thickness is not intuitive in that it does not typically correspond to how artists use most real-world tools outside the field of digital arts, and as such can feel unnatural or counter-intuitive. 
       SUMMARY OF THE INVENTION 
       [0008]    This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the invention, nor is it intended to be used to limit the scope of the invention. 
         [0009]    Embodiments of the present invention are directed to techniques for improved touch screen user-input devices that combine the benefits of active and passive touch screen implementations. According to one or more embodiments of the present invention, a system is provided that includes a user input touch device (such as a stylus) that can be equipped with one or more tips of various sizes and shapes, and a touch screen input surface that is configured to detect each of the various tips. In contrast to prevailing conventional active stylus implementations, this allows touch screen implementations to use styluses with tips that simulate real-world artistic tools that are currently not available in digital arts media. Moreover, data detected (or pre-determined) in the touch input device itself is communicated to the touch screen processor/controller to supplement the input data received in the touch screen device. 
         [0010]    In one or more embodiments, the user input touch device is equipped with a circuit that is configured to wirelessly communicate data corresponding to characteristics of the device. According to such embodiments, a computing device paired to the user input touch device is also included, which comprises a wireless receiver configured to receive the data, an input surface or touch screen implemented using a plurality of capacitive sensors, and a processor configured to implement a touch controller that manages and coordinates the operation of the capacitive sensors. The touch controller is configured to, for example, detect a position of the user input touch device and the shape of the tip of the user input touch device based on one or more contact points between the touch device and the input surface. According to one or more embodiments, the data transmitted from the input touch device is used to supplement touch-detection data determined with the capacitive sensors and processed by the touch controller to improve accuracy and precision of both the input and the type of input received. 
         [0011]    According to another embodiment, a method is provided for generating touch input data using a hybrid stylus and a capacitive touch screen. In one or more embodiments, this method includes detecting a touch input generated by a touch input device in a touch screen; generating, in a touch controller of a touch screen device comprising a plurality of capacitive sensors, a data corresponding to a position and tip shape of a user input touch device; receiving, from the user input touch device over a wireless communication connection, data corresponding to a plurality of characteristics of the user input touch device; supplementing the generated signal with the data corresponding to a plurality of characteristics of the user input touch device; and calculating touch input from the supplemented signal. 
         [0012]    According to further embodiments, generating the signal comprising data corresponding to the position and tip shape of a user input touch device may comprise, for example: measuring relative accumulated charges in a plurality of capacitive sensors, determining at least one contact point corresponding to the position of the user input touch device based on the relative accumulated charges, measuring a discharge rate at the at least one contact point, determining a tip shape corresponding to the user input touch device based on the discharge rate, and generating the signal based on the determined position and tip shape corresponding to the user input touch device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The accompanying drawings are incorporated in and form a part of this specification. The drawings illustrate embodiments. Together with the description, the drawings serve to explain the principles of the embodiments: 
           [0014]      FIG. 1  depicts a diagram of an exemplary touch input device with a plurality of input interfaces, in accordance with various embodiments of the present invention. 
           [0015]      FIG. 2A  depicts an exemplary touch input detection in a touch screen device of a touch input device with a first input interface, in accordance with various embodiments of the present invention. 
           [0016]      FIG. 2B  depicts an exemplary touch input detection in a touch screen device of a touch input device with a second input interface, in accordance with various embodiments of the present invention. 
           [0017]      FIG. 2C  depicts an exemplary touch input detection in a touch screen device of a touch input device with a third input interface, in accordance with various embodiments of the present invention. 
           [0018]      FIG. 2D  depicts an exemplary touch input detection in a touch screen device of a touch input device with a fourth input interface, in accordance with various embodiments of the present invention. 
           [0019]      FIG. 3  depicts a flowchart of an exemplary process for calculating touch input in a touch screen device, in accordance with various embodiments of the present invention. 
           [0020]      FIG. 4  depicts a flowchart of an exemplary process for determining a position and tip shape of a touch input device in a touch screen, in accordance with various embodiments of the present invention. 
           [0021]      FIG. 5  depicts an exemplary computing system upon which embodiments of the present invention may be implemented, in accordance with various embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Reference will now be made in detail to the preferred embodiments of the invention, a method and system for a hybrid touch input device, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to be limit to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope as defined by the appended claims. 
         [0023]    Furthermore, in the following detailed descriptions of embodiments of the invention, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be recognized by one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the invention. 
         [0024]    Some portions of the detailed descriptions that follow are presented in terms of procedures, steps, logic blocks, processing, and other symbolic representations of operations on data bits that can be performed on computer memory. These descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. A procedure, computer generated step, logic block, process, etc., is here, and generally, conceived to be a self-consistent sequence of steps or instructions leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. 
         [0025]    It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the present invention, discussions utilizing terms such as “storing,” “creating,” “protecting,” “receiving,” “encrypting,” “decrypting,” “destroying,” or the like, refer to the action and processes of a computer system or integrated circuit, or similar electronic computing device, including an embedded system, that manipulates and transforms data represented as physical (electronic) quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. 
         [0026]    Embodiments of the invention are directed to novel solutions for improved touch input interfaces using hybrid touch input devices. 
       Hybrid Touch Input Device 
       [0027]      FIG. 1  depicts a diagram of an exemplary touch input device  101  with a plurality of input interfaces, in accordance with various embodiments of the present invention. As depicted in  FIG. 1 , a touch input device  101  according to one or more embodiments of the present invention may include a body  103 , and a tip  104 . According to one or more embodiments, the touch input device  101  may be implemented as a stylus, with a relatively thin, bacillar body  103  shaped similarly to a writing utensil such as a pen, pencil, or brush, with roughly the same or analogous dimensions. The body  103  may, in one or more embodiments, be implemented as a hollow or relative hollow shell composed from any number of electrically conductive materials suitable to be comfortably grasped and held. As depicted in  FIG. 1 , the touch input device  101  includes a tip  104  implemented with a tip base  105  and a nib ( 107   a ,  107   b ,  107   c ). The tip  104  may also be composed of one or more electrically conductive materials, and is attached at one end of the body  103  at a corresponding end of the tip base  105 . Attached on the other end of the tip base  105  is an electrically conductive nib  107   a  operable to generate touch input in a compatible touch screen (e.g., a capacitive sensing touch screen). 
         [0028]    Tips may be equipped with nibs ( 107   a ,  107   b ,  107   c ) of varying shapes and sizes. In one or more embodiments, the tip  104  (via tip base  105 ) can be decoupled (removed) from the body  103  and replaced with another tip to suit various purposes. As depicted in  FIG. 1 , tip  104  may be attached and detached using a grooved (e.g., screw) type mechanism on the end of the tip base  105  opposite of the nib ( 107   a ,  107   b ,  107   c ). Other attachment means may include clips, magnets, or other mechanisms for fastening the tip base  105  to the body  103 . In still further embodiments, tip  104  may be statically coupled to the body  103  with only the particular nib (e.g.,  107   a ,  107   b , and  107   c ) being adjustable and replaceable. For example, nib  107   a  is depicted with a ball point, which may be preferred by users for handwriting endeavors. Similarly, nib  107   b  is depicted with a chisel tip, which may be preferred by users for marking or highlighting. Nib  107   c  is depicted with a brush tip, which may be preferred for digital painting. Thus, users are able to advantageously switch between multiple tips  104  depending on the particular intended usage of the touch input device  101 . 
         [0029]    As depicted in  FIG. 1 , touch input device  101  may also include a circuit  109  and a wireless transceiver  111 . As depicted in  FIG. 1 , both the circuit  109  and the wireless transmitter  111  can be disposed within the interior of the body  103 . As depicted in  FIG. 1 , the wireless receiver may be communicatively coupled to the circuit  109  via a bus. In one or more embodiments, the circuit  109  may be implemented as, for example, a printed circuit board (PCB) with one or more of a processor and memory device collectively configured to determine various parameters of a touch input and/or of the touch input device. In addition, the circuit  109  may include one or more sensors configured to determine usage data, such as a pressure sensor operable to detect a pressure applied by a user to the touch input device  101 , a gyroscope to determine an orientation of the touch input device  101 , and an accelerometer to determine movement of the touch input device  101 . Other parameters of the touch input and/or of the touch input device that can be detected by the circuit  109  include data corresponding to the tip type or tip shape to determine the specific tip currently attached to the touch input device  101  (e.g., nib  107   a , nib  107   b , nib  107   c ). 
         [0030]    In still further embodiments, touch input device  101  may also include one or more user-operated controls  113  (e.g., push buttons) which can be activated (via, for example, user-applied pressure) by the user. The user-operated controls  113  may be implemented according to a variety of implementations that include, for example, any mechanism which can be toggled, and/or selected between. The user-operated controls may be pre-programmed and/or programmable to perform one or more operations (e.g., generate one or more signals as user-input) when actuated. In still further embodiments, touch input device  101  may also include one or more end units  115  disposed on an opposite end of the body  103  from the tip  104 . The end unit  115  may also be implemented from an electrically conductive material and be used to generate a specific touch input when applied to a touch screen device. For example, the end unit  115  may be implemented as a dedicated erasing unit, which, when the touch input device is positioned so that the end unit  115  is rendered upside-down (as determined by a gyroscope, for example) and applied to a touch screen, previously detected user input displayed in a touch screen display can be removed that corresponds to the positions in the touch screen at which touch input from the end unit  115  is detected. 
         [0031]    In still further embodiments, characteristics of the touch input device  101  and/or parameters of a usage of the touch input device  101  can also be determined by circuitry and/or components disposed in the touch input device  101 . For example, data corresponding to a relative current velocity, orientation, angle, etc. of the touch input device  101  may be calculated to accurately determine and/or infer the intended usage of the touch input device by generating and detecting signal data or referencing pre-determined configuration data in components in the touch input device and sending that data as wireless signal data from the wireless transceiver  111  to one or more corresponding wireless transceivers in a paired touch screen. The circuits and/or sensor components in the touch input device may include, but are not limited to, components such as an accelerometer, a compass, a tip detection mechanism, or gyroscope. The data generated in these sensors or circuits may correlate to usage information, such as the direction of travel of the touch input device, how the device is held or being used, writing tendencies or characteristics of the user. This information can be used to supplement, supersede, or even contradict information calculated by a touch controller based on the electric signals generated in the touch sensors of the touch screen. 
         [0032]    For example, position detection using touch sensors still experience a latency between when the touch gesture is performed, when the touch gesture is detected, and how the touch gesture and position is calculated. Sharp movements therefore may not be detected as quickly or accurately using a touch controller alone. The supplementary data however may be detected and transmitted to the touch controller pre-emptively, therefore improving responsiveness. In one or more embodiments, any and/or all of the parameter or usage data described above may be accumulated by the circuit  109  (via, for example, the aforementioned sensors) or determined by sensor controllers executed by a processor and stored in caches and/or a memory device of the circuit  109 . In still further embodiments, the accumulated data may be communicated to a wireless transceiver  111  and forwarded to a wireless receiver in a corresponding touch screen device (not shown) to supplement touch input data generated by a touch screen controller in response to contact between the touch input device and the touch screen itself. 
         [0033]    In one or more embodiments, the information received from the touch input device is used as a secondary source of information to confirm or supplement the (primary) data received by the touch controller from the touch screen. By supplementing the touch input data with parameter data generated by circuits, sensors, or other components in the touch input device  101 , additional types of input or usage data can be calculated, and/or may be calculated with greater accuracy over calculations performed by the touch screen and controller alone. In addition, by generating the parameter data in the touch input device  101  itself, some of the touch input data may be eliminated from being generated in the touch screen, thereby freeing the touch screen controller to process other input data more quickly. For example, by identifying and communicating the shape of a nib (e.g.,  107   a ,  107   b ,  107   c ), the touch screen may no longer have to (continuously) determine the shape of the touch input device or calculate whether an input received from the touch screen corresponds to the tip of the touch input device or is input from another object (e.g., in multi-touch detection applications). The touch controller of the touch screen device is also able to optimize touch detection and input calculation specifically for the detected tip or nib—by, for example, entering into a dedicated mode specifically optimized for the detected tip or nib. Likewise, by supplementing position and location data with wireless triangulation, the position and location of the touch input device  101  in a surface of a touch screen device can be verified with greater speed and/or accuracy. 
         [0034]      FIGS. 2A-2D  depict exemplary touch input detection generated by a touch input device  201  in a touch screen device  207 .  FIG. 2A  depicts an exemplary touch input detection in a touch screen device  207  generated by a touch input device  201  with a first input interface, in accordance with various embodiments of the present invention.  FIG. 2B  depicts an exemplary touch input detection in the touch screen device  207  generated by the touch input device  201  with a second input interface, in accordance with various embodiments of the present invention.  FIG. 2C  depicts an exemplary touch input detection in the touch screen device  207  generated by a touch input device  201  with a third input interface, in accordance with various embodiments of the present invention.  FIG. 2D  depicts an exemplary touch input detection in a touch screen device  207  generated by a touch input device  201  with a fourth input interface in accordance with various embodiments of the present invention. 
         [0035]    As depicted in  FIGS. 2A-2D , input interfaces of the touch input device  201  may include a tip base  203  with a shaped nib. For example,  FIG. 2A  depicts a tip base  203  with a chisel-tipped nib  205   a ), whereas  FIGS. 2B, 2C, and 2D  depict, respectively, exemplary tip bases  203  with a ball-point nib  205   b , a brush-tip  205   c , and a broad-tipped nib  205   d . The tip base  203  may be statically coupled to the touch input device  201  or interchangeable with other compatible tip bases, according to various embodiments. Alternatively, the tips/nibs themselves (e.g.,  205   a ,  205   b ,  205   c , and  205   d ) may be interchangeable between tip bases  203 . In one or more embodiments, data corresponding to the size and shape of the current nib or tip coupled to the end of the touch input device  201  may be stored in a memory disposed in the touch input device  201  and/or communicated to a touch screen controller of a touch screen device to assist in touch input detection. 
         [0036]    As depicted in  FIGS. 2A-2D , touch screen device  207  may include a touch screen  209 , implemented as a surface (such as glass) above an arrangement of capacitive sensors. In one or more embodiments, the arrangement comprises a layer of projective capacitive sensors in a grid, which, when a voltage is supplied across the layer, forms a uniform electrostatic field. When an electrically conductive object, such as a human finger or the touch input devices described above, approaches or contacts the surface, the electrostatic field is distorted, and the charge accumulated in the capacitive sensors is drained (using the object or object-user as a ground) proportionally with respect to the proximity of the input, such that capacitive sensors closest to a point of contact experience the greatest change. The change in voltage across the sensors is detected by a touch controller (typically by measuring the frequency of an oscillator or signal corresponding to the sensor) and a touch input is registered. 
         [0037]    In one or more embodiments, the rate at which an electrical charge is drained may also be measured and used to determine the particular tip shape. For example, due to the varying shapes and contact points of the nibs and tips ( 205   a ,  205   b ,  205   c ,  205   d ), touch input can be registered at multiple sensors from a single contact. For example, a chisel-tipped nib (e.g.,  205   a ) may register touch input at multiple contact points (e.g., A, B, C), thereby having a proportionally greater impact on the capacitive sensors most proximate to those contact points. However, due to the angle of the chisel-tipped nib  205   a , the end of the nib with the further projection (corresponding to contact point A) may begin draining the charge at an earlier moment in time—however briefly—than the end of the nib corresponding to the last contact point (C), or drain at a faster rate (e.g., a discharge rate). It is appreciated that the number, position, and discharge rate of the contact points may vary for each tip or nib. For example, ball-point nib  205   b  and broad-tipped nib  205   d  are each depicted in  FIGS. 2B and 2D  (respectively) with two contact points (A, B), however, the ball-point nib  205   b  may have contact points with greater proximity to each other relative to a broad tipped nib  205   d . On the other hand, brush  205   c  is depicted in  FIG. 2C  with three contact points (A, B, C), but where ball-point nib  205   b  and broad-tipped nib  205   d  may (or may not) discharge at relatively similar rates at each of their contact points, brush  205   c  may discharge at a greater rate at the contact point closest to its center of mass (e.g., contact point b), and may discharge at decreasingly lower rates at contact points farthest away from the center of mass. 
         [0038]    In still further embodiments, a contact point is registered only once the drop in voltage and/or rate of discharge is determined to be above a pre-determined threshold for a period of time. In addition, the orientation and/or grip of the user may also factor into which contact points are registered and in what sequences. Thus, the position of a touch input device  201  may be determined by detecting where in the capacitive sensor grid a drop in voltage and accumulated charge is experienced, and the specific shape of the touch input device  201  may be determined by measuring the discharge rate at each point of contact of the touch input device  201 . In one or more embodiments, the discharge rate and number of possible points of contact corresponding to each tip or nib may be pre-stored (e.g., in a table) and determined and/or corroborated by referencing the pre-stored data. 
         [0039]    As described above, embodiments of the present inventive concepts include tips and nibs of various sizes and shapes, some of which are capable of generating contact points with areas significantly smaller or larger than contact points generated by traditionally used objects (e.g., fingers, styluses). Some embodiments may include, for example, fine-tipped nibs capable of generating contact points with areas as small as 1 millimeter in diameter or less. According to such embodiments, the pitch (e.g., the areas enclosed by capacitive sensor lines forming the touch screen grid) may be reduced to increase sensitivity to smaller contact points. The pitch may be reduced by, for example, increasing the density and number of sensor lines in the grid. Alternately, a higher voltage may be supplied to increase the sensitivity of the sensors to detect finer contact points. According to these embodiments, the touch screen devices described herein may be equipped with a higher density of capacitive sensing features, or operated using a higher supplied voltage to provide a touch screen capable of detecting contact points at least as small as 1 millimeter in diameter. 
         [0040]      FIG. 3  depicts a flowchart of an exemplary process  300  for calculating touch input in a touch screen device, in accordance with various embodiments of the present invention. Steps  301 - 309  describe exemplary steps of the flowchart  300  in accordance with the various embodiments herein described. According to some embodiments, some or all of the steps  301 - 307  may be performed by one or more touch controllers executed by one or more processors (specifically, in a touch screen device). 
         [0041]    At step  301 , a touch input is detected in a touch screen device. In one or more embodiments, the touch input corresponds to a touch input device, such as a stylus. Touch input may be detected in a touch screen of the touch screen device by detecting (via measurement) a drop in voltage and/or accumulated charge in one or more capacitive sensors comprised in the touch screen. In one or more embodiments, the capacitive sensors comprise projective capacitive sensors arranged in one or more layers as a two dimensional array (grid), configured to drain an accumulated charge upon contact with an electrically conductive object (such as a stylus or other touch input device). 
         [0042]    At step  303 , the position and tip parameter/characteristic data of the touch input is generated. Generation of the position data is described in greater detail below, with respect to  FIG. 4 . At step  305 , input device parameter data is received from the touch input device whose touch input was detected at step  301 . Input device parameter data may include, for example, identification data corresponding to the user input device (e.g., model, version, serial number), data corresponding to the hardware in the device (e.g., processor, memory, wireless communication capabilities) or the software executing in the device (firmware version, application version). Device parameter data may also include data determined in the input device from one or more sensors. For example, orientation data may be generated by a gyroscope in the input device and included in the device parameter data. Likewise, velocity data may be determined by accelerometers in the input device and included in the device parameter data. The input device parameter data may also include position/location data generated in the input device (e.g., via wireless triangulation). In one or more embodiments, the input device parameter data received in step  305  also includes data (e.g., tip size and shape, number of contact points, etc.) corresponding to the tip currently equipped by the input device data. In still further embodiments, the input device data may also include data corresponding to a user actuation of user operable controls. 
         [0043]    In one or more embodiments, the input device parameter data may be received wirelessly, through, for example, a radio-frequency communication such as WiFi, Bluetooth (BT), or near-field communication (NFC) from a paired device equipped with wireless communication capability. Alternately, the input device parameter data may be received through a physical wired connection between the input device and the touch screen device. According to one or more embodiments, the parameter data may be received continuously while the touch input device is used and/or a touch input is detected in the touch screen device. 
         [0044]    At step  307  of  FIG. 3 , the position and tip data generated at step  303  is supplemented with the device parameter data received in step  305  and the aggregated input data is provided to the touch controller of the touch screen device. In one or more embodiments, the aggregated input data may be used to update the position and tip data generated at step  303  in the touch controller. Alternately, or in addition, the aggregated input data may be stored in a memory or the cache of the processor executing the touch controller. The touch input is thereafter calculated at step  309  from the supplied data to register a more accurate and precise touch input. 
         [0045]      FIG. 4  depicts a flowchart of an exemplary process  400  for determining a position and tip shape of a touch input device in a touch screen, in accordance with various embodiments of the present invention. Steps  401 - 409  describe exemplary steps of the flowchart  400  in accordance with the various embodiments herein described. According to some embodiments, some or all of the steps  401 - 407  may be performed during the performance of step  303  by one or more touch controllers executed by one or more processors (specifically, in a touch screen device). 
         [0046]    Steps  401  and  403  correspond to determining the position in the touch screen of a touch input device generating touch input by measuring drops in voltage (accumulated charge). At step  401 , the relative accumulated charges in the capacitive sensors of the touch screen are measured. The accumulated charges may be measured by a touch controller in the touch screen device based on the electrical charge in the one or more capacitive sensors. When a drop voltage beyond a threshold is detected, the amount of the drop(s) and/or the remaining charge(s) are measured to determine the sensors in the sensor grid that have experienced the greatest drops. The sensors with the greatest drops typically correspond to the sensors most proximate to contact points of the touch input device, and the position in the touch screen is determined at step  403  by identifying which sensors correspond to the contact point(s) of the touch input device. 
         [0047]    Steps  405  and  407  correspond to determining the size and shape of an interface (e.g., tip) of a touch input device by measuring the discharge rate of charges resulting from the touch input. At step  405 , the drainage rate of the affected sensors in step  401  is measured, and the size and shape is determined at step  407  based on the measured rates of drain. In one or more embodiments, the drainage rates of affected sensors correspond to the proximity of those sensors to one or more contact points. Multiple affected sensors each draining at sufficient rates to correspond to proximity to a contact point over a distributed area would thus imply that the touch input device either has many contact points at multiple corners, or a contact surface that covers the distributed area. Determining between the two may be performed by measuring the drainage rate of sensors within the perimeter established by the distributed area, where relatively constant drainage rates would imply a larger contact surface, and inconsistent drainage rates imply multiple, interspersed contact points. Thus, determining the total area of the affected sensors in addition to the sensors experiencing drainage at the highest rates may be used to approximate the shape and size of the input object. In one or more embodiments, detection of the tip size and/or shape causes the touch controller to enter a different mode optimized specifically for the detected tip size and/or shape. For example, for touch input devices equipped with tips with single, smaller contact surfaces (e.g., points), touch detection may be optimized for precision with the threshold for detecting a contact point adjusted to eliminate mis-detections or noise. Alternately, the particular touch controller mode may be optimized to more efficiently distinguish between tips with a single large contact surface or tips with multiple contact surfaces distributed over an entire area. 
         [0048]    At step  409 , the position data determined at step  403  and the size and shape data determined at step  407  is combined and transmitted to a touch controller in a touch screen device paired with the touch input device. In one or more embodiments, the tip size and shape may be verified by the touch screen device by referencing a pre-stored data structure (e.g., table) of known touch input interfaces (e.g., touch input device tips) in one or more of the touch screen device and the touch input device. 
       Exemplary Computing Device 
       [0049]    As presented in  FIG. 5 , an exemplary system upon which embodiments of the present invention may be implemented includes a touch screen device, such as touch screen computing system  500 . In its most basic configuration, touch screen computing system  500  typically includes at least one processing unit  501  and memory, and an address/data bus  509  (or other interface) for communicating information. Depending on the exact configuration and type of computing system environment, memory may be volatile (such as RAM  502 ), nonvolatile (such as ROM  503 , flash memory, etc.) or some combination of the two. 
         [0050]    Touch screen computing system  500  may also comprise an optional graphics subsystem  505  for presenting information to the user, e.g., by displaying information on an attached display device  510 . According to embodiments of the present claimed invention, the display device  510  may include one or more light emitting elements, such as a liquid crystal display (LCD) or light emitting diodes (LEDs), over which a touch screen  513  comprising a conductive surface (like glass) and a grid of capacitive sensors operated and managed by a touch controller is disposed. In one or more embodiments, the graphics subsystem  505  may be coupled directly to the display device  510  through a graphics bus  511 . A graphical user interface executing in the touch screen computing system  500  may be generated in the graphics subsystem  505 , for example, and displayed to the user in the display device  510 . In one embodiment, the processes  300  and  400  may be performed, in whole or in part, by graphics subsystem  505  in conjunction with the processor  501  and memory  502 , with any resulting output displayed in attached display device  510 . 
         [0051]    Additionally, touch screen computing system  500  may also have additional features/functionality. For example, touch screen computing system  500  may also include additional storage (removable and/or non-removable) including, but not limited to, magnetic or optical disks or tape. Such additional storage is illustrated in  FIG. 5  by data storage device  504 . Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. RAM  502 , ROM  503 , and data storage device  504  are all examples of computer storage media. 
         [0052]    Touch screen computing system  500  also comprises an optional alphanumeric input device  506 , an optional cursor control or directing device  507 , and one or more signal communication interfaces (input/output devices, e.g., a network interface card)  508 . In one or more embodiments, at least one of the alphanumeric input device  506  and directing device  507  may be implemented as a virtual alphanumeric input device or directing device through the combination of the graphical user interface rendered by the graphics subsystem  505  and the touch screen device  513 . Optional alphanumeric input device  506  can communicate information and command selections to central processor  501 . Optional cursor control or directing device  507  is coupled to bus  509  for communicating user input information and command selections to central processor  501 . Signal communication interface (input/output device)  508 , also coupled to bus  509 , can be a serial port. Communication interface  509  may also include wireless communication mechanisms. Using communication interface  509 , touch screen computing system  500  can be communicatively coupled to other computer systems over a communication network such as the Internet or an intranet (e.g., a local area network), or can receive data (e.g., a digital television signal). 
         [0053]    Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims. 
         [0054]    In the foregoing specification, embodiments have been described with reference to numerous specific details that may vary from implementation to implementation. Thus, the sole and exclusive indicator of what is the invention, and is intended by the applicant to be the invention, is the set of claims that issue from this application, in the specific form in which such claims issue, including any subsequent correction. Hence, no limitation, element, property, feature, advantage, or attribute that is not expressly recited in a claim should limit the scope of such claim in any way. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.