Patent Description:
The touch-screen includes a Flat Panel Display (FPD) integrated with a digitizer sensor. Integration may be based on the digitizer sensor overlaid on the FPD, integrated on a protective glass layer of the FPD (on-cell technology) or integrated as part of the FPD (in-cell technology). The digitizer sensor typically includes a matrix of electrode junctions arranged in rows and columns.

The signal emitted by the active stylus is picked up by the digitizer sensor when electrostatic coupling is established between the writing tip and a portion of the matrix of electrode junctions. The electrostatic coupling is a result of proximity of the writing tip to the digitizer sensor. Positions of the writing tip over the screen are correlated with virtual information portrayed on the touch-screen. Digitizer sensors that track signals emitted by the stylus also typically track input provided with a finger or conductive object. A mutual capacitive sensor is one type of digitizer sensor that is integrated with FPD to form a touch-screen. <CIT> describes a stylus may have an elongated body with opposing first and second ends. Electronic equipment may have a touch sensor that receives electromagnetic signals from one or more electrodes at the first end. The stylus may have a six-axis inertial sensor at the second end. Force sensors may be located at the first and second ends. User input from the force sensors, the inertial sensor, and other input-output devices may be used to supply the stylus with mode change commands. In response to the mode change commands the stylus may transition between operating modes such as a touch sensor mode and one or more inertial sensor modes. Inertial sensor data may be used to allow the stylus to operate as a joystick, a rotational controller, an air mouse, or other input devices in addition to serving as a touch sensor input device. <CIT> describes a stylus for use with a digitizer sensor includes a housing confined by a first and second end, a primary tip positioned at the first end of the housing and associated with a first transmitting element, the first transmitting element having a first diameter, a secondary tip positioned at the second end of the housing and associated with a second transmitting element, the second transmitting element having a second diameter that is larger than the first diameter, a transmitting unit for transmitting a first signal with a first amplitude via the first transmitting element and for transmitting a second signal with a second amplitude via the second transmitting element, wherein the first amplitude is at least twice the second amplitude and a powering unit for powering transmission of the first and second signal.

Known active styluses are limited in their functionality. For example, they have not successfully replaced the conventional mouse. One of the limitations of the active stylus when operated as a mouse is the inconvenience of having to operate the stylus over the touch-screen. At times positioning the stylus over the touch-screen may obstruct the user's view. In addition, cursor control based on moving the writing tip over the touch-screen may be limited due to size of the screen and resolution of the digitizer sensor.

According to aspects of some embodiments of the present disclosure, additional and improved functionality is added to the active stylus by adding a pointing stick or an optical sensor to the stylus. Input from the pointing stick or the optical sensor may then be transmitted to the computing device via another wireless channel, e.g. Bluetooth communication, near field communication (NFC), radio frequency (RF) that is independent from the electrostatic channel of the touch-screen. According to some example embodiments, a stylus may automatically switch between transmission via the electrostatic channel associated with the touch-screen and transmission via another wireless channel based on sensing proximity of the stylus to the touch-screen.

Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the disclosure, example methods and/or materials are described below.

Some embodiments of the disclosure are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the disclosure. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the disclosure may be practiced.

The disclosure in some embodiments relates to an active stylus that is configured to provide input to a device based on its writing tip touching and hovering over a touch-screen of the device and is also configured to provide input to the device based on a user actuating a sensor integrated on a housing of the stylus. The additional input provided by the sensor may improve the functionality of the stylus when operated for controlling a cursor displayed on the touch-screen and may also provide additional functionality.

In some example embodiments, the sensor is a pointing stick, e.g. a trackpoint sensor integrated on a tail end of the stylus. A user may conveniently operate the pointing stick by holding the stylus and pushing the pointing stick with a thumb or a finger. The pointing stick may sense axial force in two dimensions or in three dimensions. Optionally, the pointing stick provides air mouse functionality and joystick functionality. In some example embodiments, input from the pointing stick and input from the writing tip are combined and are used by the device for gesture control or improved joystick control. In some example embodiments, input from a pressure sensor integrated with the writing tip provides an Z data and control that may be combined with X-Y data detected with the pointing stick.

In other example embodiments, the sensor is an optical sensor configured to track movement of the stylus on a surface other than the touch-screen. The optical sensor may provide mouse functionality. In some example embodiments, the optical sensor is configured to track movement both while the stylus is positioned horizontally on a surface and while the stylus is positioned in a writing orientation. Optionally, the stylus additionally includes buttons for right mouse click and left mouse click and a sensing strip to control scrolling and thereby provide full mouse emulation.

According to some example embodiments, a user may seamless switch between using the writing tip over the touch-screen to provide input via the electrostatic channel and using one of the pointing stick and the optical sensor to provide input via an alternate wireless channel.

Reference is now made to <FIG> showing a simplified block diagram of an example multi-functional stylus and a touch enabled computing device. A stylus <NUM> may include a writing tip <NUM> that provides touch input to a touch-screen <NUM> of a touch enabled device <NUM> and may also include a pointing stick <NUM> or an optical sensor <NUM> based on which a user may provide additional input with stylus <NUM> for controlling objects displayed on the touch screen or for providing electronic inking.

In some example embodiments, the additional input may be transmitted to a host <NUM> of device <NUM> via a wireless communication channel <NUM> between wireless communication unit <NUM> and module <NUM> of host <NUM>. Communication unit <NUM> may be a channel with Bluetooth communication, near field communication (NFC), radio frequency (RF) communication.

Touch input may be detected and tracked based on stylus <NUM> emitting signal <NUM> via tip <NUM> and digitizer sensor <NUM> picking up signal <NUM> at a location near writing tip <NUM>. Signal <NUM> may be a pulsed signal transmitted at a defined repeat rate, e.g. every <NUM>-<NUM> msec. In some examples, the pulsed signal includes a position signal (or beacon) and a train of data defining a plurality of parameters. The parameters may be directly related to stylus <NUM>, related to an environment around the stylus <NUM>, related to a user using stylus <NUM>, related to privileges allotted to the stylus <NUM>, ma specify capabilities of stylus <NUM>, or provide information received from a sensor such as a optical sensor <NUM> or a pointing stick <NUM>. Information related to stylus <NUM> may include indications of a pressed button(s) <NUM>, pressure level on tip <NUM> as detected by a tip sensor included in stylus <NUM>, tilt, identification, manufacturer, version, media access control (MAC) address, and stored configurations such as color, tip type, brush, and add-ons.

Optionally, digitizer sensor <NUM> may be a grid based capacitive sensor formed with row and column conductive strips <NUM> or a matrix of electrode junctions not necessarily constructed based on row and column conductive strips. A digitizer circuit <NUM> samples output from conductive strips <NUM> to detect stylus signals pick up by digitizer sensor <NUM>. Coordinates of stylus <NUM> and data transmitted by stylus <NUM> may be determined from the signals picked up by digitizer sensor <NUM>. In some examples, digitizer circuit <NUM> manages pairing with stylus <NUM>. Processing of the stylus signal <NUM> may be with digitizer circuit <NUM> or with host <NUM>.

Digitizer circuit <NUM> may also apply mutual capacitance detection or a self-capacitance for sensing a touch signal from touch (or hover) of fingertip <NUM> from a hand <NUM>. During mutual capacitance and self-capacitance detection, digitizer circuit <NUM> sends a triggering signal, e.g. pulse to one or more conductive strips <NUM> of digitizer sensor <NUM> and samples output from conductive strips <NUM> in response to the triggering. Coordinates of fingertip <NUM> may be computed by digitizer circuit <NUM> or by host <NUM> from the sampled output. The triggering signal may also be used by stylus <NUM> as an uplink signal based on which stylus <NUM> identifies the digitizer system and synchronizes with its detection periods.

Output from digitizer circuit <NUM> is reported to host <NUM>. The output provided to host <NUM> may include coordinates of one or more fingertips <NUM>, coordinates of writing tip <NUM> of stylus <NUM> and additional information provided by stylus <NUM>, e.g. pressure, tilt, and battery level. Host <NUM> may transmit the information to an application manager or a relevant application. Host <NUM> may also transmit data to stylus <NUM> with wireless module <NUM>.

Reference is now made to <FIG> and <FIG> showing schematic drawing of a user operating an example pointing stick on a stylus to interact with a computing device while the stylus is positioned on the touch-screen and away from the touch-screen respectively. In some example embodiments, a pointing stick <NUM> is installed at a tail end of a stylus <NUM> opposite an end including writing tip <NUM>. Pointing stick <NUM> may sense applied force in the X and Y direction and may be actuated by pushing with a thumb or fingers in the general direction the user wants the cursor to move. Optionally, pointing stick is also sensitive to force applied in the Z direction as when pushing pointing stick in a longitudinal direction of stylus <NUM>. Optionally, mouse click may be emulated based on force applied in the Z direction. In some example embodiments, one of the X or Y directions of pointing stick <NUM> may be aligned with a marking <NUM> on stylus <NUM> to provide indication of the control directions. Input from pointing stick <NUM> may be transmitted to a device <NUM> and may be applied to move a cursor <NUM>. A velocity at which cursor <NUM> moves may be related to the force applied on pointing stick <NUM>. Increasing the force that a user applies on pointing stick <NUM> increases the velocity at which cursor <NUM> moves. A relation between applied force and cursor speed can be adjusted, similar to the way mouse speed is known to be adjusted. In other example embodiments, pointing stick <NUM> may be used as a joystick. Input provided to device <NUM> by pointing stick <NUM> may be similar to the input provided by a trackpoint button integrated on a keyboard. Optionally, additional data is provided based on Z control included in pointing stick <NUM>.

According to some example embodiments, sensed force in the X, Y and Z directions, or commands based on the sensor force may be transmitted to a touch enabled device. In some example embodiments, the electrostatic channel may be used to transmit the data or commands when stylus <NUM> is positioned over touch-screen <NUM> (<FIG>). Optionally, force data may be modulated on a signal transmitted by stylus <NUM>. In other examples, the data or commands may be transmitted via an alternate wireless channel <NUM> while stylus <NUM> is displaced from touch-screen <NUM>.

In some example embodiments, input from pointing stick <NUM> may be detected while a stylus is paired with touch screen <NUM> and input from pointing stick <NUM> may be applied for gesture control.

Reference is now made to <FIG> showing a simplified block diagram of a stylus including an example pointing stick on a tail end of the stylus. According to example embodiments, a stylus <NUM> includes a circuit <NUM>, e.g. an application specific integrated circuit (ASIC) that may control operation of the stylus, a power source <NUM>, e.g. one or more batteries and a wireless transmission unit <NUM> all housed in a housing <NUM> of stylus <NUM>. Optionally, power source <NUM> is configured for being recharged for example in a garage associated with device <NUM>. Stylus <NUM> additionally includes a writing tip <NUM> extending from one end of stylus <NUM> and a pointing stick <NUM> extending from an opposite end of stylus <NUM>. In some example embodiments, force applied on pointing stick <NUM> in the X and Y direction may be sensed with a sensor <NUM> and force applied in the Z direction may be sensed with a sensor <NUM>. Optionally, sensor <NUM> may be a tip switch that toggles based on pressing in the Z direction. Sensor <NUM> may be for example a pair of linear magnetic encoders or a pair of resistive strain gauges. Direction of X-Y sensors may be visually indicated by aligning one of the X or Y directions, e.g. the Y direction with a clip <NUM> of stylus <NUM> or other indication on housing <NUM> that is apparent to a user. ASIC <NUM>, e.g. the stylus control circuit may control transmission of output from sensors <NUM> and <NUM> via writing tip <NUM> or via wireless module <NUM>.

Reference is now made to <FIG> showing a schematic drawing of an example pointing stick sensor in a neutral and pushed positioned respectively. Optionally, pointing stick <NUM> may be connected to an elastic or compressible element <NUM> that is housed in a pyramid structure <NUM>. Pyramid structure <NUM> may include four walls <NUM> aligned in a defined X and Y direction and may be fixed or integrated with housing <NUM>. Electrodes <NUM> may be patterned or positioned on each of the four walls of pyramid <NUM>. Inner walls <NUM> may provide electrical isolation between electrodes <NUM> and elastic element <NUM>. Electrodes <NUM> may be connected to ASIC <NUM>. Elastic element <NUM> may be rounded, e.g. spherically or hemi-spherically shaped and may include conductive material. Flattening of elastic element <NUM> increases capacitive coupling between elastic element <NUM> and one or more of the electrodes <NUM> on the pyramid structure.

As pointing stick <NUM> is pushed, elastic element <NUM> presses and flattens against one or more inner walls <NUM> of pyramid structure <NUM>. Elastic element <NUM> may flatten against each of wall <NUM> with varying degrees based on a direction and magnitude of the force applied on pointing stick <NUM>. Direction and magnitude of the force applied on pointing stick <NUM> may be sensed based on a sensed capacitive coupling with each of the electrodes <NUM>. Force applied in the Z direction may be based on a symmetric force detected on each of electrodes <NUM> while force applied in the X or Y direction may be based on asymmetric force applied on electrodes <NUM>.

Reference is now made to <FIG> showing a simplified flow chart of an example method for operating a pointing stick integrated on a tail end of an active stylus. In some example embodiments, a circuit in a stylus is senses a tilt force on pointing stick in an X-Y directions (block <NUM>). For example circuit <NUM> may sense tilt force applied on pointing stick <NUM> of stylus <NUM> (<FIG>). Optionally, a circuit in the stylus may translate the sensed tilt force to X-Y displacement data (block <NUM>). In some example embodiments, the pointing stick is also sensitive to a force applied in a longitudinal direction of the stylus that presses the pointing stick into the stylus housing (block <NUM>). In some example embodiments, a longitudinal force above a defined threshold may be translated as a button press command (block <NUM>). Optionally, the circuit in the stylus may detect the button press command. X-Y displacement data and button press data may be transmitted by via the electrostatic channel while a writing tip of the stylus is positioned on the touch-screen (block <NUM>) and may be transmitted by wireless transmission (block <NUM>) while the stylus is displaced from the touch-screen.

Reference is now made to <FIG> showing schematic drawing of a user operating an optical sensor on a stylus in a horizontal and tilted orientation respectively. In some example embodiments, multiple functionality is added to a stylus by integrating an optical sensor <NUM> on an active stylus <NUM>. Optical sensor <NUM> may sense movement of stylus <NUM> along a surface <NUM>. Surface <NUM> may be a surface other than the touch-screen <NUM>, e.g. a tabletop (<FIG>) or a surface on a laptop computer (<FIG>). In some example embodiments, optical sensor <NUM> may be oriented and configured to track a user's hand <NUM> moving stylus <NUM> while the stylus is positioned horizontally on a surface <NUM> (<FIG>) and while stylus <NUM> is held in a writing position (<FIG>). Optical sensor <NUM> may be operated in a same manner as a conventional optical mouse. Optical sensor <NUM> may detect two dimensional movement on surface <NUM> and transmit input to a computing device <NUM> via a wireless communication channel <NUM> based on the movement sensed. Input to computing device <NUM> may control position of a cursor <NUM> on touch-screen <NUM> without stylus <NUM> directly interacting with touch-screen <NUM> and may also be used to provided electronic inking <NUM>. In some example embodiments, inking with optical sensor <NUM> may be performed with a higher resolution as compared to inking based on the electrostatic interface with touch-screen <NUM>.

Reference is now made to <FIG> showing a simplified block diagram of a stylus including an example optical sensor with optional additional buttons and scroll sensor feature. A stylus <NUM> may include an optical sensor <NUM> integrated on a portion of housing <NUM> that is tapered toward writing tip <NUM>. Optionally, in this orientation, optical sensor <NUM> may be operated while a user is holding stylus <NUM> in a writing position. Optionally, in this orientation, optical sensor <NUM> may also be operated while stylus <NUM> is laying down on a surface (<FIG>). Alternatively, optical sensor <NUM> may be integrated along a portion of housing <NUM> that is not tapered and only operable while stylus <NUM> is laying flat against a surface.

Optical sensor <NUM> may include a Light Emitting Diode (LED) <NUM> that emits a light through an optical window <NUM>. Light emitted by LED <NUM> may be reflected from a surface, e.g. tabletop back through optical window <NUM> and captured by a image sensor <NUM>. Optionally, image sensor <NUM> is associated with optics <NUM>. A processor <NUM> may compare a series of images to detect movement of optical window <NUM>. In some example embodiments, optical sensor <NUM> includes a first image sensor <NUM> positioned and oriented to capture images while the stylus is being held in a writing position and includes a second image sensor <NUM> positioned and oriented to capture images while the stylus is positioned flat against a surface Processor <NUM> may detect images captured from each of the image sensors and select data from image sensor <NUM> that provides the best results. Optionally, stylus <NUM> includes a gyroscope and processor <NUM> may select one of the two image sensors to actuate for tracking based input from the gyroscope.

Stylus <NUM> may additionally include one or two user manipulated buttons <NUM> that provide mouse right click and mouse left click functionality. In some example embodiments, stylus <NUM> additional includes a capacitive sensing strip <NUM> integrated along a length of housing <NUM> that can be operated by a user's finger to provide a scroll command by sliding a finger along capacitive sensing strip <NUM>. Optical sensor <NUM>, buttons <NUM> and strip <NUM> may be controlled by ASIC <NUM>. Input to a computing device <NUM> based on commands sensed with optical sensor <NUM>, buttons <NUM> and strip <NUM> may be transmitted with a wireless communication unit <NUM>. Operation of optical sensor <NUM>, buttons <NUM> and strip <NUM> and wireless communication unit <NUM> may be powered by a power source <NUM> in stylus <NUM>. Optionally power source <NUM> is a rechargeable battery.

Reference is now made to <FIG> showing a simplified flow chart of an example method for operating a stylus with an optical sensor. Optical sensor may be selectively activated by a controller of the stylus, e.g. ASIC <NUM> and a wakeup command by the controller may initiate activation of the optical sensor (block <NUM>). The optical sensor may be maintained in a sleep mode while the stylus is paired with a touch-screen of a computing device and may be activated based on sensing a break in the pairing. Optionally, a user may initiate activation of the optical sensor based on pressing a button on the stylus, e.g. one of buttons <NUM>.

In some example embodiments, orientation of the stylus may be detected (block <NUM>) and sensing of the optical sensor may be adjusted to the orientation detected (block <NUM>). Based on sensed data, X-Y displacement commands are determined provided to stylus controller (block <NUM>). The commands may then be transmitted by wireless transmission (block <NUM>). Mouse tracking with the optical sensor may be selectively turned off by a controller of the stylus (block <NUM>).

Claim 1:
A stylus (<NUM>) configured for interacting with a touch screen (<NUM>), the stylus comprising:
an elongated housing (<NUM>) including a first end and a second end, wherein the second end is opposite the first end;
a tip (<NUM>) extending from the first end of the elongated housing, wherein the tip is configured to interact with a digitizer sensor of the touch screen;
a first wireless transmitter (<NUM>) configured to transmit a signal via the tip;
a pointing stick (<NUM>) at the second end;
a tri-axial force sensor (<NUM>, <NUM>) mounted on the second end, wherein the tri-axial force sensor is configured to sense contact force applied by a user pressing the pointing stick and wherein the tri-axial force sensor (<NUM>) includes four walls (<NUM>) aligned in a defined X and Y direction to form a pyramid structure each wall having an electrode (<NUM>) positioned thereon wherein the Z direction is along the longitudinal direction of the stylus, wherein in the Z direction a symmetric force is detectable on each of the electrodes (<NUM>) and wherein in the X or Y direction an asymmetric force is detectable on each of the electrodes (<NUM>);
a second wireless transmitter (<NUM>) configured to transmit output sensed by the tri-axial force sensor; and
a controller (<NUM>) configured to control transmission of the first wireless transmitter and the second wireless transmitter.