Touch sensor device with modulated control signal for communication with active stylus

Abstract

Device comprising: a readout unit which, in operation, can read a first signal from one or more control lines of a touch sensor, wherein the touch sensor comprises the control lines and one or more readout lines, and the control lines together with the readout lines form capacitive nodes; and a control unit which, in operation, can transmit a second signal based on the first signal to the readout lines, whereby the transmission of the second signal changes a perceived capacitance at each of one or more of the capacitive nodes.

Description

Technical area

[0001] The present disclosure relates generally to touch sensors. background

[0002] A touch position sensor can detect the presence and location of an object or the proximity of an object (such as a user's finger or a stylus) within a touch-sensitive area of ​​the touch sensor, which is, for example, overlaid on a display screen. In a touch-sensitive display application, the touch position sensor can enable the user to interact directly with what is shown on the display, rather than indirectly, such as with a mouse or touchpad. A touch sensor can be mounted on or incorporated into a desktop computer, a laptop computer, a tablet computer, a personal digital assistant (PDA), a smartphone, a satellite navigation device, a portable media player, a portable game console, a kiosk computer, a point-of-sale system, or other suitable device.A control panel on a household appliance or other device may contain a touch sensor.

[0003] There are a number of different types of touch position sensors, such as (for example) resistive touch screens, surface acoustic wave touch screens, and capacitive touch screens. Hereinafter, reference to a touch sensor may include a touch screen, and vice versa. When an object touches or approaches the surface of the capacitive touch screen, a capacitance change may occur within the touch screen at the location of the touch or approach. A controller may process the capacitance change to determine its location on the touch screen.

[0004] US 2011 / 0122087 A1 describes a touchscreen system comprising a touchscreen panel including drive lines, sensor lines crossing the drive lines, and sensor cells formed at intersections of the drive lines and sensor lines; a drive circuit for sequentially applying drive signals to the drive lines; a sensor circuit for detecting first sensor signals corresponding to changes in the mutual capacitances of the sensor cells to generate second sensor signals corresponding to the changes; a processor for determining a touch position based on the second sensor signals from the sensor circuit;and an active stylus separate from the touchscreen panel and configured to output an active stylus electric field synchronously with a drive signal of the drive signals applied to a drive line coupled to a sensor cell of the sensor cells adjacent to the active stylus when the active stylus approaches or touches the touchscreen panel;

[0005] DE 11 2008 000 906 T5 describes a two-dimensional position sensor based on capacitive proximity sensing technology. The sensor comprises a substrate with a sensitive area defined by an electrode pattern, the pattern containing drive electrodes and readout electrodes. These electrodes are arranged in the X and Y directions and are capacitively coupled. The sensor measures the position of an object by disrupting the capacitive coupling caused by the proximity of a pointing object and uses a control unit to apply drive signals and measure readout signals.

[0006] DE 10 2010 003 575 A1 describes an electronic device having a mutually capacitance-sensing touchscreen or touchpad with combined finger navigation, navigation with a movable stylus, and character input capability. First and second pluralities of detection and drive electrodes are arranged in or on at least one substrate to form an array configured to enable the detection of a first position corresponding to a finger or a second position corresponding to a movable stylus. The drive electrodes in the array are configured to operate as detection electrodes when the touchscreen or touchpad is operated in a first finger touch mode and to operate as additional detection electrodes when the touchscreen or touchpad is operated in a second movable stylus mode.

[0007] DE 11 2008 001 800 B4 describes a touch-sensitive capacitive inversion sensor, comprising: a touch panel having a plurality of sensing elements distributed over its surface; a capacitance measurement circuit connected to the sensing elements and arranged to repeatedly detect sets of capacitance signal values, each set consisting of a capacitance signal value from each of the sensing elements; and a processor connected to receive the sets of capacitance signal values ​​and arranged to process each set to calculate and output coordinates of single or multiple touch points on the touch panel. Short description of the drawings Fig. 1 shows an example touch sensor. Fig. 2 illustrates an exterior view of an exemplary active stylus. Fig. 3 shows an inside of an exemplary active stylus. Fig. Figure 4 illustrates an example active stylus with a touch sensor device. Fig. Figure 5 shows an example array of electrodes. Fig. 6 illustrates an exemplary method for modulating a drive signal for communication between an active stylus and a touch sensor device. Description of exemplary embodiments

[0008] Fig. 1 illustrates an example touch sensor 10 with an example controller 12. Touch sensor 10 and touch-sensor controller 12 can detect the presence and location of a touch or the proximity of an object within a touch-sensitive area of ​​touch sensor 10. Hereinafter, reference to a touch sensor may include both the touch sensor and its touch-sensor controller, where appropriate. Likewise, reference to a touch-sensor controller may include both the touch-sensor controller and its touch sensor, where appropriate. Touch sensor 10 may include one or more touch-sensitive areas, where appropriate.Touch sensor 10 may include an array of drive and sense electrodes (or an array of electrodes of a single type) disposed on one or more substrates, which may be made of a dielectric material. Hereinafter, reference to a touch sensor may include both the electrodes of the touch sensor and the substrate(s) on which they are disposed. Alternatively, reference to a touch sensor may include the electrodes of the touch sensor but not the substrate(s) on which they are disposed.

[0009] An electrode (either a ground electrode, a guard electrode, a drive electrode, or a sense electrode) may be a region of conductive material forming a particular shape, such as a circular disk, a square, a rectangle, or any other suitable shape or combination of these shapes. One or more cuts in one or more layers of conductive material may (at least in part) form the shape of an electrode, and the area of ​​the shape may be (at least in part) defined by these cuts. In certain embodiments, the conductive material of an electrode may cover approximately 100% of the area of ​​its shape. As a non-limiting example, an electrode may be made of indium tin oxide (ITO), and the ITO of the electrode may optionally occupy approximately 100% of the area of ​​its shape.In certain embodiments, the conductive material of an electrode may occupy substantially less than 100% of the area of ​​its shape. As a non-limiting example, an electrode may be formed from thin lines of metal or other conductive material (such as copper, silver, or a copper- or silver-containing metal), and the thin lines of conductive material may occupy substantially less than 100% of the area of ​​its shape as a hatch, mesh, or other suitable pattern. Although the present disclosure describes specific electrodes made of specific conductive material having a specific shape with a particular fill in a particular pattern, the present disclosure contemplates any suitable electrodes made of any suitable conductive material forming any suitable shapes with any suitable fills in any suitable patterns.Where appropriate, the shapes of the electrodes (or other elements) of a touch sensor may, in whole or in part, constitute one or more macrofeatures of the touch sensor. One or more properties of the implementation of these shapes (such as the conductive material, fills, or patterns within the shapes) may, in whole or in part, constitute one or more microfeatures of the touch sensor. One or more macrofeatures of a touch sensor may determine one or more properties of its functionality, and one or more microfeatures of the touch sensor may determine one or more optical features of the touch sensor, such as transparency, refraction, or reflection.

[0010] A mechanical stack may include the substrate (or multiple substrates) and the conductive material forming the drive or sense electrodes of touch sensor 10. As a non-limiting example, the mechanical stack may include a first layer of optically clear adhesive (OCA) beneath a cover panel. The cover panel may be transparent and made of a material suitable for repeated touch, such as glass, polycarbonate, or poly(methyl acrylate) (PMMA). The present disclosure contemplates any suitable cover panels made of any suitable material. The first layer of OCA may be disposed between the cover panel and the substrate with the conductive material forming the drive or sense electrodes.The mechanical stack may also include a second layer of OCA and a dielectric layer (which may be made of PET or other suitable material similar to the substrate with the conductive material forming the drive or sense electrodes). Alternatively, a thin coating of a dielectric material may optionally be applied in place of the second layer of OCA and the dielectric layer. The second layer of OCA may be disposed between the substrate with the conductive material forming the drive or sense electrodes and the dielectric layer, and the dielectric layer may be disposed between the second layer of OCA and an air gap adjacent to a display of a device including the touch sensor 10 and the touch-sensor controller 12.In one non-limiting example, the cover panel may have a thickness of 1 millimeter (mm), the first layer of OCA may have a thickness of approximately 0.05 mm, the substrate with the conductive material forming the drive or sense electrodes may have a thickness of approximately 0.05 mm, the second layer of OCA may have a thickness of approximately 0.05 mm, and the dielectric layer may have a thickness of approximately 0.05 mm. Although the present disclosure describes a specific mechanical stack having a specific number of specific layers of specific materials with a specific thickness, the present disclosure contemplates any suitable mechanical stack having any suitable number of suitable layers consisting of any suitable materials with any suitable thickness.As a non-limiting example, in certain embodiments, a layer of adhesive or dielectric may replace the dielectric layer, the second layer of OCA, and the air gap described above, such that no air gap exists on the display.

[0011] One or more portions of the substrate of touch sensor 10 may be made of polyethylene terephthalate (PET) or other suitable material. The present disclosure contemplates any suitable substrate, with any suitable portion being made of any suitable material. In particular embodiments, the drive or sense electrodes in touch sensor 10 may be made entirely or in part of ITO. In certain embodiments, the drive or sense electrodes in touch sensor 10 may be made of thin lines of metal or other conductive material. As a non-limiting example, one or more portions of the conductive material may be made of copper or copper-containing material and have a thickness of approximately 5 micrometers (µm) or less and a width of approximately 10 µm or less.In another example, one or more portions of the conductive material may be silver or silver-containing and may also have a thickness of about 5 μm or less and a width of about 10 μm or less. The present disclosure contemplates any suitable electrodes made of any suitable material.

[0012] Touch sensor 10 may implement a capacitive form of touch sensing. In a mutual capacitance implementation, touch sensor 10 may include an array of drive and sense electrodes forming an array of capacitive nodes. A drive electrode and a sense electrode may form a capacitive node. The drive and sense electrodes forming the capacitive node may come close to each other but do not make electrical contact. Instead, the drive and sense electrodes may be capacitively coupled across a gap between them. A pulsating or alternating voltage applied to the drive electrode (by touch-sensor controller 12) may induce a charge on the sense electrode, and the amount of induced charge may depend on external influences (such as a touch or the proximity of an object).When an object touches or approaches the capacitive node, a capacitance change may occur at the capacitive node, and touch-sensor controller 12 may measure the capacitance change. By measuring capacitance changes across the array, touch-sensor controller 12 may determine the location of the touch or proximity within the touch-sensitive area(s) of touch sensor 10.

[0013] In a self-capacitance implementation, touch sensor 10 may include an array of electrodes of a single type, each of which may form a capacitive node. When an object touches or comes close to the capacitive node, a change in self-capacitance may occur at the capacitive node, and touch-sensor controller 12 may measure the change in capacitance, e.g., as a change in the amount of charge required to increase the voltage at the capacitive node by a predetermined amount. As with a mutual-capacitance implementation, by measuring changes in capacitance across the array, touch-sensor controller 12 may determine the location of the touch or proximity within the touch-sensitive area(s) of touch sensor 10. This disclosure may contemplate any suitable form of capacitive touch sensing.

[0014] In specific embodiments, one or more drive electrodes may together form a drive line that runs horizontally or vertically or in any suitable orientation. Likewise, one or more sense electrodes may together form a sense line that runs horizontally or vertically or in any suitable orientation. In certain embodiments, the drive lines may be substantially perpendicular to sense lines. Hereinafter, reference to a drive line may optionally include one or more drive electrodes forming the drive line, and vice versa. Likewise, reference to a sense line may optionally include one or more sense electrodes forming the sense line, and vice versa.

[0015] Touch sensor 10 may have drive and sense electrodes arranged in a pattern on one side of a single substrate. In such a configuration, a pair of drive and sense electrodes capacitively coupled to each other across a gap between them may form a capacitive node. In a self-capacitance implementation, only one type of electrode may be arranged in a pattern on a single substrate. In addition to, or as an alternative to, drive and sense electrodes arranged in a pattern on one side of a single substrate, touch sensor 10 may have drive electrodes arranged in a pattern on one side of a substrate and sense electrodes arranged in a pattern on another side of the substrate.Furthermore, touch sensor 10 may have drive electrodes arranged in a pattern on one side of the substrate and sense electrodes arranged in a pattern on a side of another substrate. In such configurations, an intersection of a drive electrode and a sense electrode may form a capacitive node. Such an intersection may be a location where the drive electrode and sense electrode "cross," or are closest to each other in their respective planes. The drive and sense electrodes do not make electrical contact with each other, but instead are capacitively coupled via a dielectric at the intersection.Although the present disclosure describes specific configurations of particular electrodes forming particular nodes, the present disclosure contemplates any suitable configuration of any suitable electrodes forming any suitable nodes. Furthermore, the present disclosure contemplates any suitable electrodes arranged on any suitable number of suitable substrates in any suitable patterns.

[0016] As described above, a change in capacitance at a capacitive node of touch sensor 10 may indicate a touch or proximity input at the location of the capacitive node. Touch-sensor controller 12 may detect and process the change in capacitance to determine the presence and location of the touch or proximity input. Touch-sensor controller 12 may then communicate information about the touch or proximity input to one or more components (such as one or more central processing units (CPUs) or digital signal processors (DSPs)) of a device that includes touch sensor 10 and touch-sensor controller 12, which may then respond to the touch or proximity input by initiating a function of the device (or an application running on it) associated with it.Although the present disclosure describes a particular touch-sensor controller having particular functionality with respect to a particular device and a particular touch sensor, the present disclosure contemplates any touch-sensor controller having any suitable functionality with respect to any suitable device and any suitable touch sensor.

[0017] Touch-sensor controller 12 may consist of one or more integrated circuits (ICs), such as general-purpose microprocessors, microcontrollers, programmable logic devices or arrays, and application-specific integrated circuits (ASICs). In certain embodiments, touch-sensor controller 12 includes analog circuitry, digital logic, and digital non-volatile memory. In certain embodiments, touch-sensor controller 12 is disposed on a flexible printed circuit (FPC) board that is connected to the substrate of touch sensor 10, as described below. The board may be active or passive. In certain embodiments, multiple touch-sensor controllers 12 may be disposed on the board. Touch-sensor controller 12 may include a processor unit, a drive unit, a readout unit, and a memory unit.The drive unit can supply drive signals to the drive electrodes of touch sensor 10. The readout unit can sense charge at the capacitive nodes of touch sensor 10 and provide measurement signals to the processor unit representing capacitance at the capacitive nodes. The processor unit can control the drive unit's supply of drive signals to the drive electrodes and process measurement signals from the drive unit to detect and process the presence and location of a touch or proximity input within the touch-sensitive area(s) of touch sensor 10. The processor unit can also track changes in the position of a touch or proximity input within the touch-sensitive area(s) of touch sensor 10.The memory unit may store programs for execution by the processor unit, including programs for controlling the drive unit to supply the drive signals to the drive electrodes, programs for processing the measurement signals from the readout unit, and optionally other suitable programs. Although the present disclosure describes a particular touch-sensor controller having a particular implementation with particular components, the present disclosure encompasses any suitable touch-sensor controller having any suitable implementation with any suitable components.

[0018] Traces 14 of conductive material disposed on the substrate of touch sensor 10 can connect the drive or sense electrodes of touch sensor 10 to connection pads 16 also disposed on the substrate of touch sensor 10. The connection pads 16 enable coupling of the traces 14 to touch-sensor controller 12, as described below. The traces can extend into or around the touch-sensitive area(s) of touch sensor 10 (e.g., at its edges). Certain traces 14 can provide drive connections for coupling touch-sensor controller 12 to drive electrodes of touch sensor 10, through which the drive unit of touch-sensor controller 12 can provide drive signals to the drive electrodes.Other conductive traces 14 may provide sense connections for coupling touch-sensor controller 12 to sense electrodes of touch sensor 10, through which the sense unit of touch-sensor controller 12 may sense charges at the capacitive nodes of touch sensor 10. The conductive traces 14 may be formed from thin lines of metal or other conductive material. In one non-limiting example, the conductive material of the conductive traces 14 may be copper or copper-containing and have a width of approximately 100 µm or less. In another example, the conductive material of the conductive traces 14 may be silver or silver-containing and have a width of approximately 100 µm or less. In certain embodiments, the conductive traces 14 may be formed entirely or partially from ITO in addition to, or as an alternative to, thin lines of metal or other conductive material.Although the present disclosure describes particular traces made of particular materials with particular widths, the present disclosure contemplates any suitable traces made of any suitable materials with any suitable widths. In addition to traces 14, touch sensor 10 may include one or more ground lines terminating at a ground connector (which may be a bonding pad 16) on an edge of the substrate of touch sensor 10 (similar to traces 14).

[0019] Connection pads 16 may be arranged along one or more edges of the substrate outside the touch-sensitive area(s) of touch sensor 10. Touch-sensor controller 12 may be located on a printed circuit board (PCB), as described above. Connection pads 16 may be made of the same material as traces 14 and may be adhered to the PCB using an anisotropic conductive film (ACF). In some embodiments, interconnect 18 may include conductive lines on PCB 12 that couple touch-sensor controller 12 to connection pads 16, which in turn couple touch-sensor controller 12 to traces 14 and the drive or sense electrodes of touch sensor 10. In other embodiments, connection pads 16 may be incorporated into an electromechanical connector (such asA zero-insertion cable-to-circuit board connector may be inserted. In these embodiments, connection 18 need not include a circuit board. The present disclosure contemplates any suitable connection 18 between touch-sensor controller 12 and touch sensor 10.

[0020] Fig. 2 illustrates an exemplary exterior of an exemplary active stylus 20. In certain embodiments, the active stylus 20 is powered (i.e., via an internal or external power source) and is capable of receiving touch or proximity inputs to a touch sensor (e.g., the touch sensor shown in Fig. 1). The active stylus 20 may include one or more components, such as buttons 30 or sliders 32 and 34, integrated into an external body 22. These external components may enable interaction between the active stylus 20 and a user or between a device and a user. As a non-limiting example, interactions may include communication between the active stylus 20 and a device, activating or changing functionality of the active stylus 20 or a device, or generating feedback to or receiving input from one or more users.The device may be any suitable device, such as, but not limited to, a desktop computer, a laptop computer, a tablet computer, a personal digital assistant (PDA), a smartphone, a satellite navigation device, a portable media player, a portable game console, a kiosk computer, a point-of-sale device, or any other suitable device. Although this disclosure provides specific examples of certain components configured to enable certain interactions, this disclosure contemplates any suitable component configured to enable any suitable interaction. The active stylus 20 may have any suitable dimensions, with the outer body 22 being made of any suitable material or combination of materials, such as, but not limited to, plastic or metal.In certain embodiments, external components (e.g., 30 or 32) of the active stylus 20 may interact with internal components or programs of the active stylus 20 or trigger one or more interactions with one or more devices or other stylus devices 20.

[0021] Actuating one or more components may, as described above, initiate an interaction between the active stylus 20 and a user, or between the device and the user. Components of the active stylus 20 may include one or more buttons 30 or one or more sliders, called sliders 32 and 34. In one non-limiting example, the buttons 30 or sliders 32 and 34 may be mechanical or capacitive and act as a roller, a trackball, or a wheel. In another example, one or more sliders 32 or 34 may act as a vertical slider 34 aligned along a longitudinal axis of the active stylus 20, while one or more wheel sliders, called wheel sliders 32, may be aligned around the perimeter of the active stylus 20.In certain embodiments, capacitive sliders 32 and 34 or buttons 30 may be implemented using one or more touch-sensitive areas. The touch-sensitive areas may have any suitable shape, dimensions, and positions, or be made of any suitable material. In one non-limiting example, the sliders 32 and 34 or buttons 30 may be implemented using areas of flexible fabric formed using lines of conductive material. In another example, the sliders 32 and 34 or buttons 30 may be implemented using a printed circuit board.

[0022] The active stylus 20 may include one or more components configured to provide feedback or receive feedback from a user, such as, but not limited to, tactile, visual, or audible feedback. The active stylus 20 may include one or more ridges or grooves 24 on its outer body 22. The ridges or grooves 24 may have any suitable dimensions, any suitable spacing between the ridges or grooves, or be located in any suitable area on the outer body 22 of the active stylus 20. In one non-limiting example, the ridges 24 may enhance a user's grip on the outer body 22 of the active stylus 20 or provide tactile feedback or receive feedback from a user.The active stylus 20 may include one or more acoustic components 38 capable of sending and receiving acoustic signals. In one non-limiting example, acoustic or audio components 38 may include a microphone capable of recording or transmitting the voice(s) of a user or users. The audio component 38, in another example, may generate an audible indication of a power status of the active stylus 20. The active stylus 20 may include one or more visual feedback components 36, such as an LED indicator or electrophoretic ink (E-Ink). In one non-limiting example, the visual feedback component 36 may indicate a power status of the active stylus 20 to the user.

[0023] One or more modified surface areas 40 may form one or more components on the outer body 22 of the active stylus 20. The properties of the modified surface areas 40 may differ from the properties of the remaining surface of the outer body 22. As a non-limiting example, the modified surface area 40 may be modified to have a surface texture, temperature, or electromagnetic characteristic that differs from the surface properties of the remaining outer body 22. The modified surface area 40 may be capable of dynamically changing its properties, for example, using haptic interfaces or rendering methods. A user may interact with the modified surface area to enable any suitable functionality.As one non-limiting example, dragging a finger across the modified surface area 14 may initiate an interaction, such as data transfer, between the active stylus 20 and a device.

[0024] One or more components of the active stylus 20 may be configured to transmit data between the active stylus 20 and the device. For example, the active stylus 20 may include one or more tips 26 or pen tips. Tip 26 may include one or more electrodes configured to transmit data between the active stylus 20 and one or more devices or other active stylus devices. Tip 26 may generate or transmit pressure information (e.g., the amount of pressure applied across tip 26 by the active stylus 20) between the active stylus 20 and one or more devices or other active stylus devices 20. Tip 26 may be made of any suitable material, such as a conductive material, and may have any suitable dimensions, such as a diameter of 1 mm or less, at its outer end.The active stylus 20 may include one or more connectors 28 located at any suitable location on the outer body 22 of the active stylus 20. Connector 28 may be configured to transmit signals or information between the active stylus 20 and one or more devices or power sources, for example, via a wired connection. Connector 28 may transmit signals or information using any suitable technology, such as USB or Ethernet connections. Although the present disclosure describes and illustrates a particular configuration of certain components having particular locations, dimensions, compositions, and functionality, the present disclosure contemplates any suitable configuration of suitable components having any suitable locations, dimensions, compositions, and functionality with respect to the active stylus 20.

[0025] Fig. 3 illustrates example internal components of an example active stylus 20. The active stylus 20 includes one or more internal components, such as a controller 50, sensors 42, memory 44, or power source 48. In certain embodiments, one or more internal components may be configured to enable interaction between the active stylus 20 and a user, or between a device and a user. In other specific embodiments, one or more internal components may be configured, in conjunction with one or more external components as described above, to enable interaction between the active stylus 20 and a user, or between a device and a user.As one non-limiting example, interactions may include communication between the active stylus 20 and a device, enabling or changing functionality of the active stylus 20 or a device, or providing feedback to or receiving input from one or more users. In another example, the active stylus 20 may communicate over an appropriate short-range, low-power data transmission or modulation link, such as, but not limited to, a radio frequency communication link. In this case, the active stylus 20 includes an RF device for transmitting data over the RF link.

[0026] Control unit 50 may be a microcontroller or any other type of processor suitable for controlling the function of the active stylus 20. Control unit 50 may be one or more integrated circuits, such as general-purpose microprocessors, microcontrollers, PLDs, PLAs, or ASICs. Control unit 50 may include a processor unit, a drive unit, a readout unit, and a memory unit. The drive unit may supply signals to electrodes from tip 26 via center shaft 41. The drive unit may further supply signals for controlling sensors 42 or one or more external components of the active stylus 20. The readout unit may acquire signals received from electrodes from tip 26 via center shaft 41 and provide measurement signals representing input from a device to the processor unit.The readout unit can further acquire signals generated by sensors 42 or one or more external components and provide measurement signals representing input from a user to the processor unit. The processor unit can control the supply of signals to the electrodes of tip 26 and process measurement signals from the readout unit to acquire and process input from the device. The processor unit can further acquire measurement signals from sensors 42 or one or more external components.The memory unit may store programs for execution by the processor unit, including, where appropriate, programs for controlling the drive unit to supply signals to the electrodes of tip 26, programs for processing measurement signals from the readout unit corresponding to input from the device, programs for processing measurement signals from sensors 42 or external components to initiate a predetermined function or gesture to be performed by the active stylus 20 or the device, or other suitable programs. In one non-limiting example, programs executed by control unit 50 may electronically filter signals received from the readout unit.Although the present disclosure describes a particular controller having a particular implementation with particular components, the present disclosure contemplates any suitable controller having any suitable implementation with any suitable components.

[0027] In certain embodiments, the active stylus 20 may include one or more sensors 42, such as touch sensors, gyroscopes, accelerometers, contact sensors, or any other type of sensor used to collect or measure data about the environment in which the active stylus 20 operates. Sensors 42 may collect and measure one or more characteristics of the active stylus 20, such as acceleration or movement, orientation, contact, pressure on the outer body 22, the force at tip 26, vibration, or any other suitable characteristic of the active stylus 20. The sensors 20 may be implemented, for example, but not limited to, mechanical, electronic, or capacitive. Data collected or measured by the sensors 42Measured data transmitted to control unit 50 can, as described above, trigger a predetermined function or gesture to be performed by the active stylus 20 or the device. In certain embodiments, data sensed or received by the sensors 42 can be stored in memory 44. Memory 44 can be any form of memory suitable for storing data in the active stylus 20. In other specific embodiments, control unit 50 can access data stored in memory 44. In one non-limiting example, memory 44 can store programs for execution by the processor unit of control unit 50. In another example, data measured by the sensors 42 can be processed by control unit 50 and stored in memory 44.

[0028] Power source 48 may be any type of stored energy source, including electrical or chemical energy sources, suitable for operating active stylus 20. In certain embodiments, power source 48 may be charged with energy from a user or a device. In one non-limiting example, power source 48 may be a rechargeable battery charged by motion induced on active stylus 20. In other particular embodiments, power source 48 of active stylus 20 may supply or receive power from the device or another external power source. In one non-limiting example, power may be transferred inductively between power source 48 and a power source of the device or another external power source, such as a wireless power transfer device.The power source may also be powered by a wired connection via a suitable connector coupled to a suitable power source.

[0029] Fig. 4 illustrates an example active stylus 20 with an example device 52. Device 52 may include a display (not shown) and a touch sensor with a touch-sensitive area 54. Display 52 may be a liquid crystal display (LCD), an LED display, an LED-backlit LCD, or other suitable display, and may be visible through a cover and substrate (and the touch sensor drive and sense electrodes disposed thereon) of device 52. Although the present disclosure describes a particular device display and particular types of displays, the present disclosure contemplates any suitable display and any suitable types of displays.

[0030] The electronics of device 52 may enable the functionality of device 52. As a non-limiting example, the electronics of device 52 may include circuitry or other electronics for wireless transmission to or from device 52, execution of programs on device 52, generation of graphical or other user interfaces for the display of device 52 for display to a user, management of power for device 52 from a battery or other power source, capture still images, record video, other suitable functions, or any combination thereof. Although the present disclosure describes particular device electronics that enable particular functionality of a particular device, the present disclosure contemplates any suitable device electronics that enable any suitable functionality of any suitable device.

[0031] In certain embodiments, the active stylus 20 and device 52 may be synchronized prior to transferring data between the active stylus 20 and device 52. In one non-limiting example, the active stylus 20 may be synchronized with device 52 via a predetermined bit sequence sent by the touch sensor of device 52. In another example, the active stylus 20 may be synchronized with the device by processing the drive signal sent by the drive electrodes of the touch sensor of device 52. The active stylus 20 may interact or communicate with device 52 when the active stylus 20 is brought into contact with or approached the touch-sensitive area 54 of the touch sensor of device 52. In certain embodiments, interaction between the active stylus 20 and device 52 may be capacitive or inductive.As one non-limiting example, when the active stylus 20 is brought into contact with or near the touch-sensitive area 54 of device 52, signals generated by the active stylus 20 may affect capacitive nodes of the touch-sensitive area of ​​device 52, or vice versa. In another example, a power source of the active stylus 20 may be inductively charged via the touch sensor of device 52, or vice versa. Although the present disclosure describes particular interactions and transfers between the active stylus 20 and device 52, the present disclosure contemplates any suitable interactions and transfers using any suitable means, such as mechanical forces, current, voltage, or electromagnetic fields.

[0032] In certain embodiments, a measurement signal from the sensors of the active stylus 20 can initiate, enable, or terminate interactions between the active stylus 20 and one or more devices 52 or one or more users, as described above. Interaction between the active stylus 20 and device 52 can occur when the active stylus 20 comes into contact with or approaches device 52. As a non-limiting example, a user can perform a gesture or sequence of gestures, such as shaking or rotating the active stylus 20, while the active stylus 20 is hovering over the touch-sensitive area 54 of device 52. The active stylus 20 can interact with device 52 based on the gesture performed with the active stylus 20 to initiate a predetermined function, such as authenticating a user associated with the active stylus 20 or device 52.Although the present disclosure describes particular movements that enable certain types of interactions between the active stylus 20 and device 52, the present disclosure contemplates any suitable movement that affects any suitable interaction in any suitable manner.

[0033] In certain embodiments, as described above in connection with Fig. 1, a touch sensor (e.g. the one in Fig. 1) may contain an array of drive and sense electrodes or an array of electrodes of a single type. These electrodes may be connected to a control unit (e.g., the one shown in Fig. 1 shown control unit 12) via special conductor tracks (e.g. in Fig. 1. The drive unit of the control unit can supply drive signals to the drive electrodes via some tracks, and the readout unit of the control unit can read charge at the capacitive nodes via other tracks. The electrodes can be arranged in various patterns, and the present disclosure contemplates any suitable patterns for the electrode arrangements. For example, Fig. 5 illustrates an exemplary array of electrodes arranged in an XY grid pattern. In certain embodiments, the drive electrodes may be arranged along a group of lines (e.g., the X lines X0 to X n-1 ) and the readout electrodes can be arranged along another group of lines (e.g. the Y lines Y0 to Y n-1). The capacitive nodes are located at one or more intersection points of the X and Y lines. A touch-sensitive area 500 can be occupied by these electrodes.

[0034] In certain embodiments, to determine the position of an object, such as a stylus or a user's finger, within a touch-sensitive area (e.g., touch-sensitive area 500), a sampling of the electrodes or coordinates within the touch-sensitive area may be performed (e.g., driving the drive electrodes and sampling the capacitive nodes within the touch-sensitive area 500). In some implementations, the drive electrodes are each driven line-by-line. That is, a number of pulses (e.g., 3 or 4 pulses) are passed through each line of drive electrodes (e.g., line X), and for each pulse, a number of signal samples (e.g., 1 or 2 samples) are read by sampling the corresponding capacitive nodes. For example, in Fig. 5 the drive electrodes along the line X0 are driven first, the charge is transferred via the capacitive coupling between the drive and the readout lines, and the corresponding capacitive nodes along the Y-lines (e.g. Y0 to Y n ) can be scanned to acquire the signal samples. Then, the drive lines along line X1 are driven next, the charge is again transferred via the capacitive coupling between the drive and sense lines, and the corresponding capacitive nodes along the Y lines are scanned to acquire the signals. This continues until the electrodes along the last line X nare controlled and the corresponding capacitive nodes along the Y-lines are sampled to acquire the signal samples. The samples may be digitally quantized (for example, via an analog-to-digital converter, a phase or frequency detector, and / or other suitable methods). The digital samples are then transmitted in individual frames. In certain embodiments, a frame contains a complete sample of some or all of the capacitive nodes within a touch-sensitive area. For example, in the Fig. In the case shown in Figure 5, a frame contains [MxN] samples, where N indicates the number of X-lines (e.g., control lines) and M indicates the number of receive lines.

[0035] In the exemplary grid of electrodes shown in Fig. As shown in Figure 5, the capacitive nodes are located at the intersections of the drive and sense electrodes. To simplify the explanation, a small portion 510 of the touch-sensitive area 500 is used here, and this portion 510 contains four capacitive nodes 511A, 511B, 511C, 511D. When a stylus moves within the touch-sensitive area 500, it may be located at a coordinate that coincides with one of the capacitive nodes, or it may be located at a coordinate that lies between a number of capacitive nodes. For example, coordinate 512A lies mostly between nodes 511A and 511B, while coordinate 512B lies between nodes 511A, 511B, 511C, and 511D.A device with a touch sensor is often capable of determining separate coordinates within its touch-sensitive area in greater numbers than the number of capacitive nodes actually contained within the touch-sensitive area. This is because coordinates between the capacitive nodes can also be detected.

[0036] In some implementations, the capacitive nodes are sampled to measure the signals (e.g., voltage levels) at those nodes. The signal for each coordinate is interpolated using the signals measured at the capacitive nodes near that coordinate. In some implementations, if a capacitive node is closer to a particular coordinate, that capacitive node has a stronger influence on that coordinate. Conversely, if a capacitive node is farther from a particular coordinate, that capacitive node has less influence on the coordinate.

[0037] In the Fig. In the exemplary case illustrated in Figure 5, for coordinate 512A, since it lies primarily between capacitive nodes 511A and 511B, the signals from capacitive nodes 511A and 511B have a stronger influence on coordinate 512A. Furthermore, since coordinate 512A lies approximately halfway between capacitive nodes 511A and 511B, the influence of the signals from capacitive nodes 511A and 511B on coordinate 512A is approximately equal. Thus, the signal at coordinate 512A can be interpolated as 50% of the signal measured at capacitive node 511A plus 50% of the signal measured at capacitive node 511B. Furthermore, since the capacitive nodes 511C and 511D are located near coordinate 512A, their influence can also be taken into account when the signal at coordinate 512A is interpolated and calculated (e.g.45% of the signal measured at capacitive node 511A + 45% of the signal measured at capacitive node 511B + 5% of the signal measured at capacitive node 511C + 5% of the signal measured at capacitive node 511D). Similarly, for coordinate 512B, its signal can be calculated by interpolating the signals measured at capacitive nodes 511A, 511B, 511C, and 511D, since this coordinate lies between these four capacitive nodes. Furthermore, since coordinate 512B is closer to capacitive nodes 511C and 511D than to capacitive nodes 511A and 511B, capacitive nodes 511C and 511D have a stronger influence on coordinate 512B than capacitive nodes 511A and 511B (e.g., 12.5% ​​of the signal measured at capacitive node 511A + 12.5% ​​of the signal measured at capacitive node 511B + 37.5% of the signal measured at capacitive node 511C + 37.5% of the signal measured at capacitive node 511D).

[0038] For example, when an object (e.g., a finger or active stylus 20) touches or comes close to a capacitive node (such as capacitive nodes 511A, 511B, 511C, and 511D), a change in capacitance at the capacitive node may be detected, and a touch-sensor controller (such as touch-sensor controller 12) may measure the detected change in capacitance. A detected change in capacitance may include an apparent or actual change in capacitance. A touch may appear to cause a change in capacitance without actually changing any stored charge. For example, if charge is added or subtracted to and / or from a node and then the resulting current flow at the integrator is measured, the capacitance at the node may appear to have increased or decreased.In this example, the charge may not be stored at the node, but rather may flow through it. By measuring sensed changes in capacitance across the entire array, the touch-sensor controller can determine the position of the touch (e.g., from a stylus or a human finger) or proximity within the touch-sensitive area(s). References to changes in capacitance throughout this document may include any sensed changes in capacitance.

[0039] Fig. 6 illustrates an exemplary method for modulating a drive signal for communication between an active stylus and a touch-sensor device. The method can be divided into two stages: a readout stage and a transmit stage. In the embodiment described below, the readout stage is performed by the readout unit of control unit 50, and the transmit stage is performed by the drive unit of control unit 50.

[0040] The readout stage may begin in step 610, in which the readout unit of control unit 50 receives a signal from control lines of a touch sensor (for example, the X lines, ie, X0 to X 10, of touch sensor 10). In step 620, the readout unit of control unit 50 filters the readout signal. For example, the readout unit may filter the readout signal with a high-pass filter or other types of filters, including both continuous and discrete-time filters. In step 630, the readout unit of control unit 50 amplifies the filtered signal. For example, the readout unit may amplify the filtered signal with an operational amplifier or other types of voltage and current amplifiers, including both continuous and discrete-time amplifiers. In some embodiments, stylus tip 26 is also biased to a virtual ground with a resistor.

[0041] In step 640, the readout unit of control unit 50 stores the amplified signal in a capacitor. In step 650, the readout unit of control unit 50 detects the presence of a trigger condition. In one example, the trigger condition is a voltage pulse in a pulse train signal transmitted through the drive lines. That is, the trigger condition may be the falling edge of the amplitude of the voltage pulse. In another example, the trigger condition is a signal peak transmitted over the one or more drive lines. For example, the readout unit may detect a signal peak transmitted over the one or more drive lines and store the amplitude of the signal peak in a peak detector or an analog-to-digital converter. A characteristic of the signal peak, such as the amplitude, may be used as the trigger condition.In some embodiments, the amplitude of the signal peak stored in the peak detector or analog-to-digital converter only becomes a trigger condition when the amplitude is higher than a minimum threshold amplitude. Teachings of certain embodiments are based on the recognition that requiring the amplitude of the signal peak to meet a minimum threshold requirement can reduce noise effects.

[0042] If the readout unit of control unit 50 detects the presence of a trigger condition, the readout unit releases the stored signal in step 660. For example, the readout unit may release the signal stored in the capacitor if the signal is above a predefined threshold. In one exemplary embodiment, the predefined threshold is a fixed voltage (e.g., 100 mV). In some embodiments, the presence of a trigger condition triggers a comparator, which compares the signal to the predefined threshold.

[0043] The transfer stage may begin in step 670, where the driver of control unit 50 determines whether the active stylus 20 is operating in "touch" mode or "non-touch" mode. Generally, when a human finger touches or comes close to a capacitive node, the touch-sensor controller may measure a reduction in the capacitance of the capacitive node. In certain embodiments, the active stylus 20 may be configured such that the capacitance of a capacitive node decreases when the active stylus 20 touches or comes close to the capacitive node. This configuration of the active stylus 20 may be referred to as "touch" mode because, in this configuration, the active stylus 20 may mimic the "touch" of a human finger by reducing the capacitance of a capacitive node.

[0044] In certain embodiments, the active stylus 20 may be configured to increase the capacitance of a capacitive node when the active stylus 20 touches or comes close to the capacitive node. This configuration of the active stylus 20 may be referred to as a "non-touch" mode because the active stylus 20 in this configuration does not resemble the "touch" of a human finger. In some embodiments, the active stylus 20 is configured to operate in both touch and non-touch modes. In some embodiments, a user can select between touch and non-touch modes, for example, by inputting a selection via buttons 30 or sliders 32 or 34.

[0045] In some implementations, it is assumed that "touch" and "non-touch" modes provide certain advantages. For example, an active stylus 20 operating in "touch" mode may work with touch sensors designed for use with human fingers. An active stylus 20 operating in "non-touch" mode may allow a touch sensor to omit certain signal processing steps. For example, if a touch sensor operates only in non-touch mode, the touch sensor may, in practice, ignore reductions in capacitance caused by human contact. For example, a touch sensor operating only in "non-touch" mode may not need to execute algorithms to determine whether a "touch" is intentional or unintentional (e.g.,accidental touches by a user's hand when writing on the touch sensor). In some embodiments, a touch sensor can operate in both "touch" and "non-touch" modes, allowing the touch sensor to distinguish between a human finger and a stylus operating in "non-touch" mode. In some embodiments, the touch sensor can specify certain capacitive nodes as operating in "touch" mode, "non-touch" mode, or both. For example, in "non-touch" mode, the host processing unit can categorize modulation from a stylus as distinct from that from a finger, since a finger does not typically generate high levels of "non-touch" and is incapable of modulating, whereas the active stylus 20 can generate high levels of "non-touch" and has circuitry capable of modulating signals.For example, a finger has a predictive signal response, while a stylus can use amplitude, phase and / or frequency modulation to send signals to the touch sensor.

[0046] When the active stylus 20 is operating in "touch" mode, the drive unit of control unit 50 may invert the phase of the signal in step 680. For example, the drive unit may receive a signal from the capacitor and convert the voltage into an inverted and multiplied drive signal for transmission to the touch sensor. In step 685, the drive unit may transmit the "touch" signal via stylus tip 26 to the sense lines of a touch sensor (e.g., the Y lines Y0 through Y n from touch sensor 10). Transmission of the inverted signal may cause a reduction in the capacitance of one or more capacitive nodes of the touch sensor.

[0047] When the active stylus 20 is operating in "non-touch" mode, the driver of control unit 50 may increase the voltage of the signal in step 690. For example, the driver may increase the signal voltage from approximately 2.5V to 10V. In this example, the driver does not change the phase of the received signal. In step 695, the driver may apply the "opposite touch" signal via stylus tip 26 to the sense lines of a touch sensor (for example, the Y lines Y0 through Y n from touch sensor 10). Transmission of the signal may cause an increase in the capacitance of one or more capacitive nodes of the touch sensor.

[0048] After the inverted signal has been transmitted to the sense lines for a sufficient time, the drive unit of control unit 50 can connect stylus tip 26 to a virtual ground and reset stylus tip 26 to a resting level prior to tip release. This allows the active stylus 20 to be in the resting state and ready for a new cycle.

[0049] In certain embodiments, the steps of the method may be Fig. 6 may be repeated if necessary. Furthermore, although the present disclosure describes certain steps of the method in Fig. 6 so that they take place in a particular order, provides that any suitable steps of the method in Fig. 6 in any suitable order. Furthermore, although the present disclosure describes and illustrates particular components, devices, or systems that perform particular steps of the method in Fig. 6, any suitable combination of any suitable components, devices or systems that perform any suitable steps of the method in Fig. 6 execute.

[0050] A reference to a computer-readable permanent storage medium herein includes, where appropriate, a semiconductor-based or other integrated circuit (IC) (such as a field-programmed gate array (FPGA) or an application-specific integrated circuit (ASIC)), a hard disk, a hard disk drive, a hybrid hard disk drive (HHD), an optical disk, an optical disk drive (ODD), a magneto-optical disk, a magneto-optical disk drive, a floppy disk, a floppy disk drive (FDD), a magnetic tape, a holographic storage medium, a solid-state drive, a RAM drive, an SD card, an SD card drive, or other suitable computer-readable, permanent storage medium, or a combination of two or more of these.

[0051] "Or" here means inclusive and not exclusive, unless otherwise stated or the context requires. "A or B" here therefore means "A, B, or both," unless otherwise stated or the context requires. Furthermore, "and" means each one individually or all together, unless otherwise stated or the context requires. "A and B" here therefore means "A and B, individually or together," unless otherwise stated or the context requires.

[0052] This disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the exemplary embodiments that one skilled in the art would contemplate. Furthermore, in the appended claims, reference to a device or system, or a component of a device or system, configured to perform a particular function includes that device, system, or component regardless of whether that particular function is enabled, turned on, or unlocked, as long as that device, system, or component is configured to perform that function.

Claims

[1] Device comprising: a readout unit operable to read a first signal from one or more drive lines of a touch sensor, wherein the touch sensor comprises the drive lines and one or more readout lines, and the drive lines together with the readout lines form capacitive nodes; and a drive unit operable to transmit a second signal based on the first signal to the sense lines, wherein transmitting the second signal changes a perceived capacitance at each of one or more of the capacitive nodes. [2] Device according to claim 1, wherein the readout unit is further configured can filter the first signal; can amplify the filtered signal; can store the amplified signal in a capacitor; can detect the presence of a trigger condition; and when the trigger condition is detected, the signal stored in the capacitor can be released if a voltage of the stored signal is above a predefined threshold. [3] The device of claim 2, wherein the trigger condition is a voltage pulse in a pulse train signal transmitted through the drive lines. [4] The device of claim 2, wherein the trigger condition is a signal peak transmitted through the drive lines. [5] The device according to claim 1, wherein the control unit is further configured can receive a signal transmitted by the trip unit; and invert a phase of the received signal to obtain the second signal, wherein transmitting the second signal reduces the perceived capacitance of the one or more capacitive nodes. [6] The apparatus of claim 1, wherein the drive unit is further operable to receive a signal transmitted from the readout unit; and increase the voltage of the received signal to obtain the second signal, wherein transmitting the second signal increases the perceived capacitance of the one or more capacitive nodes. [7] The device according to claim 6, wherein the second signal is transmitted in phase with the read-out first signal. [8] The apparatus of claim 1, further comprising a user input device operative to receive a user input selection, the user input selection indicating a choice between a first mode and a second mode, in the first mode instructing the drive unit to transmit the second signal such that perceived capacitance of the one or more capacitive nodes is reduced by transmitting the second signal, and in the second mode instructing the drive unit to transmit the second signal such that perceived capacitance of the one or more capacitive nodes is reduced by transmitting the second signal. [9] Procedure which includes: Reading a first signal from one or more drive lines of a touch sensor, wherein the touch sensor comprises the drive lines and one or more read lines, and the drive lines together with the read lines form capacitive nodes; and Transmitting a second signal based on the first signal to the sense lines, wherein transmitting the second signal changes a perceived capacitance at each of one or more of the capacitive nodes. [10] The method of claim 9, wherein reading the first signal further comprises: Filtering the first signal; Amplifying the filtered signal; Storing the amplified signal in a capacitor; Detecting the presence of a trigger condition; and Releasing the signal stored in the capacitor when a voltage of the stored signal is above a predefined threshold when the trigger condition is detected. [11] The method of claim 10, wherein the trigger condition is a voltage pulse in a pulse train signal transmitted through the drive lines. [12] The method of claim 10, wherein the trigger condition is a signal peak transmitted through the drive lines. [13] The method of claim 9, wherein transmitting the second signal further comprises: Receiving a signal transmitted by the readout unit; and Inverting a phase of the received signal to obtain the second signal, wherein transmitting the second signal reduces the perceived capacitance of the one or more capacitive nodes. [14] The method of claim 9, wherein transmitting the second signal further comprises: Receiving a signal transmitted by the readout unit; and Increasing the voltage of the received signal to obtain the second signal, wherein transmitting the second signal increases the perceived capacitance of the one or more capacitive nodes. [15] The method of claim 14, wherein the second signal is transmitted in phase with the read-out first signal. [16] One or more computer-readable permanent storage media containing logic that, when executed, can read a first signal from one or more drive lines of a touch sensor, wherein the touch sensor comprises the drive lines and one or more read lines, and the drive lines together with the read lines form capacitive nodes; and transmit a second signal based on the first signal to the sense lines, wherein transmitting the second signal changes a perceived capacitance at each of one or more of the capacitive nodes. [17] The media of claim 16, wherein the logic is further operable to filter the first signal; can amplify the filtered signal; can store the amplified signal in a capacitor; can detect the presence of a trigger condition; and when the trigger condition is detected, the signal stored in the capacitor can be released if a voltage of the stored signal is above a predefined threshold. [18] The media of claim 16, wherein the logic further functions to: can receive a signal transmitted by the readout unit; and invert a phase of the received signal to obtain the second signal, wherein transmitting the second signal reduces the perceived capacitance of the one or more capacitive nodes. [19] The media of claim 16, wherein the logic is further operable to receive a signal transmitted from the readout unit; and increase the voltage of the received signal to obtain the second signal, wherein transmitting the second signal increases the perceived capacitance of the one or more capacitive nodes. [20] Media according to claim 19, wherein the second signal is transmitted in phase with the read-out first signal.

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