WO2014061020A1

WO2014061020A1 - Digitizer system with stylus housing station

Info

Publication number: WO2014061020A1
Application number: PCT/IL2013/050836
Authority: WO
Inventors: Uri Ron; Eran AMIR; Yuval Stern
Original assignee: N-Trig Ltd.
Priority date: 2012-10-16
Filing date: 2013-10-16
Publication date: 2014-04-24

Abstract

A method for operating digitizer system that supports position detection of a stylus, the digitizer system integrated with a computing device associated with a stylus housing station is proposed. The method includes receiving indication that a stylus is placed in the housing station and altering operation of the digitizer system in response to receiving the indication that the stylus is placed in the housing station.

Description

DIGITIZER SYSTEM WITH STYLUS HOUSING STATION

FIELD AND BACKGROUND OF THE INVENTION

The present invention, in some embodiments thereof, relates to operation of a digitizer system that supports position detection of a stylus and, more particularly, but not exclusively to operation of the digitizer system integrated with a computing system that includes a housing station for the stylus.

Digitizer systems that support stylus input are known in the art. Position detection of the stylus with the digitizer system typically provides input to a computing device associated with the digitizer system and is interpreted as user commands. Some styluses operate by emitting an electromagnetic signal near a tip of the stylus. Position detection of such styluses can be performed while the stylus tip is either touching and/or hovering over a detection surface of the digitizer system. Some digitizer systems that support stylus input also support input by one or more fingertip touches. Often, the digitizer system is part of a touch screen and a position of the stylus and/or fingertip touch over the screen is correlated with virtual information rendered on the screen.

Some known digitizer systems support interaction with a stylus that is asynchronous with respect to the digitizer system. Typically, such a stylus is operative to transmit signal bursts at a pre-defined rate and the digitizer system is typically required to operate in a search mode to determine timing of the stylus burst. Typically, once the timing of the stylus burst is determined, the digitizer system synchronizes with the stylus bursts and switches to operation in a tracking mode for tracking position of the stylus.

U.S. Patent No. 7,292,229, entitled "Transparent Digitiser" assigned to N-trig Ltd., the contents of which is incorporated herein by reference, describes a method and apparatus for locating and identifying physical objects, such as a stylus or game tokens, with a digitizer arrangement. The stylus includes a resonator arrangement that is coupled across a gap formed around a writing tip of the stylus, to create an electric field concentration in the vicinity of the tip. The digitizer arrangement includes a grid-based sensor, which is preferably transparent, and which is located on top of flat panel display. An excitation coil surrounds the display screen with the digitizer arrangement and provides a trigger pulse that excites passive circuitry in the stylus to produce a response from the stylus. The response continues after the end of the excitation pulse and steadily decays. The decaying oscillations are sensed by the digitizer arrangement from which positioning of tip in the grid is determined.

U.S. Patent No. 7,372,455, entitled "Touch Detection for a Digitizer" assigned to N-trig Ltd., the contents of which is incorporated herein by reference, describes a detector for detecting both an electromagnetic stylus emitting a signal and interaction with finger touch. The detector typically includes a digitizer sensor with a grid of sensing conductive lines for sensing location of an electromagnetic stylus and a finger. The detector is capable of detecting simultaneous occurrences of multiple styluses and/or multiple finger touches.

U.S. Patent No. 8,481,872, entitled "Digitizer, Stylus and Method of Synchronization therewith," assigned to N-trig Ltd., the contents of which is incorporated herein by reference, describes a method for operating a digitizer with an autonomous asynchronous stylus. The method includes sampling outputs from a digitizer, detecting from the outputs at least one pulsed signal transmitted from an autonomous asynchronous stylus at a defined rate, determining a location of the stylus interaction with respect to the digitizer, and tracking stylus interaction with the digitizer over subsequent pulsed signals transmitted from the stylus.

U.S. Patent Application No. 2007-0146351, entitled "Position input device and computer system," the contents of which is incorporated herein by reference, describes a position input system including a position indicator for transmitting signals, and a position detector device for receiving signals transmitted from the position indicator. The position detector device is part of a computer system that includes a computer main unit, a monitor integrated with the position detector device, a keyboard, and a charger as a stand or holder for charging the position indicator. There is described a charging control process in which a user is requested to insert the position indicator to the charger in response to the position indicator providing indication that it requires charging. The computing main unit receives a charge request from the position indicator via the position detector device, displays a request to the user on the display and controls the charging process. Optionally, the computing main unit can initiate the charge request after a prescribed time period has elapsed from a previous charging session. SUMMARY OF THE INVENTION

According to an aspect of some embodiments of the present invention, there is provided a method for operating a digitizer system that supports position detection of a stylus. According to some embodiments of the present invention, the digitizer system is integrated into a computing device that includes and/or is associated with a dedicated housing station for storing, holding and/or charging the stylus while it is not being used to interact with the digitizer system. According to some embodiments of the present invention, the digitizer system is operable to receive input indicating when the stylus is positioned in the garage and to adjust its operational mode responsive to the received indication. In some exemplary embodiments, the digitizer system suspends stylus position detection while the stylus is in the garage. Optionally, the digitizer system also supports finger touch interaction and continues to detect finger touch interaction during this period. Optionally, the digitizer system initiates a stylus search mode responsive to receiving indication that the stylus has been removed from the garage.

According to an aspect of some embodiments of the present invention, there is provided a method for operating digitizer system that supports position detection of a stylus, the digitizer system integrated with a computing device associated with a stylus housing station. The method includes receiving indication that a stylus is placed in the housing station and altering operation of the digitizer system in response to receiving the indication that the stylus is placed in the housing station.

Optionally, the method includes suspending stylus detection responsive to receiving the indication that the stylus is placed in the housing station.

Optionally, the method includes receiving indication that the stylus has been removed from the housing station and resuming stylus detection responsive to receiving the indication that the stylus has been removed from the housing station.

Optionally, the digitizer system is operative to detect signals emitted by a stylus that is asynchronous with the digitizer system.

Optionally, the method includes initiating a stylus search operational mode responsive to receiving the indication that the stylus has been removed from the housing station, wherein a signal emitted by the stylus is searched for during the stylus search mode. Optionally, the digitizer system searches for the stylus at an accelerated rate for a pre-defined period after receiving indication that the stylus has been removed from the housing station and then reduced the rate after the pre-defined period has lapsed without signal emitted by the stylus being found.

Optionally, the method includes switching to a stylus tracking mode responsive to detecting a signal emitted by the stylus with the digitizer system, wherein during the stylus tracking mode coordinates of the stylus on the digitizer system are reported to the computing device.

Optionally, the digitizer system is operative to synchronize sampling for stylus detection with timing of signals emitted by the stylus.

Optionally, the digitizer system is operative to suspend transmission of a signal to the stylus in response to receiving the indication that the stylus is placed in the housing station.

Optionally, the digitizer system is operative to trigger the stylus to emit a signal. Optionally, the stylus is a conductive pointer that does not emit a signal.

Optionally, the method includes detecting finger touch interaction with the digitizer system and reporting coordinates of finger touch to the computing device.

Optionally, the method includes accelerating a rate of finger touch reporting while stylus detection is suspended.

Optionally, detecting finger touch interaction is based on a mutual capacitance touch method.

Optionally, the digitizer system is operative to alter one or more parameters and/or thresholds for detecting finger touch in response to receiving the indication that the stylus is placed in the housing Optionally, the digitizer system is operative to alter one or more parameters and/or thresholds for palm rejection in response to receiving the indication that the stylus is placed in the housing station.

Optionally, the digitizer system is a grid based capacitive sensor.

Optionally, the housing station includes a sensor for detecting presence of the stylus.

Optionally, output from the sensor is communicated with a general purpose input/output signal to the computing device. Optionally, the housing station includes a charging station for charging a power supply of the stylus.

Optionally, the computing device is operative to sense that the stylus is being charged in the charging station.

Optionally, the computing device provides indication to the digitizer system regarding presence of the stylus in the housing station.

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 to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the invention 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 invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced.

In the drawings:

FIG. 1 is simplified block diagram of an exemplary computing device including a digitizer system and stylus garage in accordance with some embodiments of the present invention;

FIG. 2 is a simplified time line showing exemplary sampling periods of the digitizer system during a stylus search operational mode in accordance with some embodiments of the present invention;

FIG. 3 is a simplified time line showing exemplary sampling periods of the digitizer system during a stylus and finger operational mode in accordance with some embodiments of the present invention; FIG. 4 is a simplified time line showing exemplary sampling periods of the digitizer system responsive to indication that the stylus is positioned in the stylus garage in accordance with some embodiments of the present invention;

FIG. 5 is a simplified time line showing exemplary sampling periods of digitizer system during an enhanced stylus search and finger operational mode in accordance with some embodiments of the present invention;

FIG. 6 is a simplified flow chart of an exemplary method for operating the digitizer system in accordance with some embodiments of the present invention;

FIG. 7 is a simplified flow chart of an additional exemplary method for operating the digitizer system in accordance with some embodiments of the present invention; and

FIGS. 8 A and 8B are simplified schematic drawings of an exemplary stylus garages associated with a laptop computer in accordance with some embodiments of the present invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

The present invention, in some embodiments thereof, relates to operation of a digitizer system that supports position detection of a stylus and, more particularly, but not exclusively to operation of the digitizer system when integrated with a computing device that includes a housing station for the stylus.

According to some embodiments of the present invention, the digitizer system is operable to receive indication(s) that a stylus is currently positioned and/or housed in housing and/or charging station, and to adjust operation of the digitizer system responsive to the indication. According to some embodiments of the present invention, the digitizer system suspends a stylus search operation and/or stylus tracking operation in response to receiving such indication. Typically, the digitizer system suspends stylus search and/or stylus tracking operation over the duration that the stylus is positioned in the housing. Optionally, other pre-defined detection and/or processing procedures are suspended in response to receiving such indication. According to some embodiments of the present invention, the digitizer system is also operable to receive indication(s) that the stylus has been removed from the housing station and to initiate a stylus search operation responsive to receiving such indication. Optionally, the stylus search operation is initiated after a delay corresponding to an estimated time it would take a user to remove the stylus from the housing and begin interacting with digitizer system.

The present inventors have found that the presence of a stylus in its housing station can be used as a clear indication that the stylus is not being used for interacting with the digitizer system and that such indication can be used by the digitizer system to adjust its operation to avoid wasting energy, time and/or processing resources on searching for the stylus while the stylus is not and/or cannot be used. In some exemplary embodiments, the energy expenditure that is saved by suspending stylus search and/or tracking is used to reduce power consumption of the computing device. In some exemplary embodiments, the energy, time and/or processing resources that are saved by suspending stylus search and/or tracking is alternatively used toward enhancing other functions performed by the digitizer system. In some exemplary embodiments, finger touch detection is enhanced over the duration that the stylus is positioned in the housing and stylus search and/or tracking are suspended. Optionally, the digitizer system increases the report rate of finger touch detection while the stylus is positioned in the housing. Typically, suspending stylus search and/or tracking while the stylus is positioned in the housing station also avoids false positive detection due to proximity of the housing to the digitizer sensor and/or due to noise picked up by the system. Not searching for stylus while it is in said housing may also simplify the digitizer operation and avoid detections of other noise sources as if they were stylus signals.

The present inventors have also found that, removal of the stylus from the housing station can provide indication that there is a high probability that stylus interaction is soon to commence. In some exemplary embodiments, the digitizer system initiates an enhanced stylus search mode with a high search rate responsive to receiving indication that the stylus has been removed from its housing station. Typically, the search rate for stylus detection that is used in the enhanced stylus search mode is higher than the search rate that is otherwise used during a search mode of the digitizer system. Optionally, the enhanced search mode is operated for a pre-defined time period. Optionally, if the stylus is not detected over the pre-defined time period of the enhanced search mode, the digitizer system switches to operating a regular search mode.

In some exemplary embodiments, the housing station includes a switch that senses insertion and removal of the stylus from the housing station, and the state of the switch is reported and used to provide indication to the digitizer system as to when the stylus is positioned in the housing station and/or has been removed from the housing station. In some exemplary embodiments, the housing station is a charging station for charging the stylus, and a charging state of the charger as sensed by the computing device is used to provide the indication to the digitizer system. Optionally, the stylus transmits information directly to the digitizer system and/or computing device to provide the indication as to when to suspend and/or reinstate stylus detection.

Reference is now made to FIG. 1 showing a simplified block diagram of an exemplary computing device including a digitizer system and stylus garage in accordance with some embodiments of the present invention. According to some embodiments of the present invention, computing device 100 includes a host computer 22, a display screen 45, a digitizer system including digitizer sensor 26 with operating circuitry 50, and a stylus garage 140 for storing a stylus 44 that is used for interacting with the digitizer system. According to some embodiments, the digitizer system is operative to sense input and/or detect position of a stylus 44 and one or more fingers 46 of a user interacting with digitizer sensor 26. Typically, coordinates of stylus 44 and one or more fingers 46 as detected by the digitizer sensor are reported to host 22.

According to some embodiments of the present invention, stylus 44 is operative to transmit and/or emit a signal 43 that can be picked up by sensor 26. Typically, signal 43 is an electric field that is generated near and/or around a writing tip of stylus 44. In some exemplary embodiments, signal 43 includes one or more signal bursts that are transmitted and/or emitted at pre-defined pulse repetition rate (PRR), e.g. emitted at a PRR falling between 10-300 Hz or a PRR of 60 Hz. Optionally, stylus 44 includes circuitry for modulating one or more of the signal bursts to include information that can be communicated to circuitry 50 and/or host 22. According to some embodiments of the present invention, stylus 44 is a self powered device that includes one or more batteries 47 or the like. Optionally, stylus 44 is rechargeable device. In some exemplary embodiments, stylus 44 includes a button and/or switch 48 that can be operated by a user for switching transmission of signal 43 ON/OFF. Optionally, stylus 44 includes additional buttons and/or switches that can be operated by a user for selecting specific functions, e.g. left click, eraser mode. In some exemplary embodiments, stylus 44 is asynchronous with the digitizer system. Optionally, stylus 44 is synchronized with the digitizer system and is operative to transmit and/or emit signal 43 responsive to a trigger signal and/or query managed by the digitizer system. Optionally, stylus 44 is a conductive pointer and does not include circuitry.

According to some embodiments of the present invention, stylus garage 140 is operable to store stylus 44 while stylus 44 is not being used to interact with digitizer sensor 26. According to some embodiments of the present invention, stylus garage 140 includes circuitry that can sense insertion (and/or removal) of stylus 44 into (or out off) stylus garage 140. According to some embodiments of the present invention, stylus garage 140 is also electrically connected or otherwise in communication with host 22 and insertion (and/or removal) of stylus 44 is reported to host 22.

In some exemplary embodiments, stylus garage 140 includes charging circuitry 136 for charging stylus 44, e.g. for recharging batteries 47. Optionally, charging circuitry 136 is powered and/or controlled by host computer 22. Optionally and/or alternatively, stylus garage 140 includes a sensing switch 138 for detecting when stylus 44 is inserted in stylus garage 140. Optionally, switch 138 is an optical interrupter switch including an emitter and detector pair. Alternatively switch 138 is a contact switch, proximity sensor and/or a magnetic sensor. Optionally, presence (and/or absence) of stylus 44 in garage 140 is detected by charging circuitry 136 and sensing switch 138 is not required. Optionally, stylus 44 is operable to senses when it is being charged to emit a signal that can be picked up by digitizer sensor 26 to indicate that it is presently being charged.

Typically, digitizer sensor 26 is overlaid on and/or otherwise integrated with display screen 45 to form a touch screen. According to some embodiments of the present invention, digitizer sensor 26 is formed with a plurality of horizontal and vertical conductive lines 18 that cross to form a grid. Typically, the horizontal conductive lines 18 and the vertical conductive lines are patterned on separated surfaces and/or layers, so that there is no physical and/or electrical contact between conductive lines 18. Alternatively, horizontal conductive lines 18 and the vertical conductive lines are patterned on the same surface but with spacers between conductive lines 18 at junction points so that there is no physical and/or electrical contact between conductive lines 18. Optionally, one or more of conductive lines 18 are shaped as lines and/or strips with varying width, e.g. resembling a sequence of diamonds or rhombuses. Optionally, conductive lines 18 are formed from transparent material and/or are structured so as not to obstruct a user's view of display screen 26.

According to some embodiments of the present invention, circuitry 50 is electrically connected to conductive lines 18 and controls operation of digitizer sensor 26. Typically, circuitry 50 includes both analog a digital components. Typically, circuitry 50 samples and processes output from conductive lines 18 of digitizer sensor 26. According to some embodiments of the present invention, circuitry 50 is operative to detect coordinates of stylus 44 or fingers 46 based on the output sampled and is also operative to report the coordinates to host 22.

Typically, during stylus detection of a signal emitting stylus, circuitry samples substantially simultaneously the output from both horizontal and vertical conductive lines 18 of sensor 26. According to some embodiments of the present invention, circuitry 50 is operative to detect signals 43 from a stylus 44 that is asynchronous with respect to the digitizer system. According to some embodiments of the present invention, circuitry 50 synchronizes with burst signals 43 emitted by stylus 44 by first operating in a stylus search mode to search for the presence and timing of burst signal 43, and then synchronizes sampling with the detected timing of burst signal 43. In some exemplary embodiments, circuitry 50 includes memory capability and the PRR of stylus 44 is stored in its memory.

According to some embodiments of the present invention, finger touch and/or hover interaction with digitizer sensor 26 is detected using a mutual capacitive detection method. Optionally, a stylus that is a conductive pointer that does not emit a signal, e.g. a passive stylus, is also detected using a mutual capacitive detection method. Alternatively, a stylus that is a conductive pointer that does not emit a signal, e.g. a passive stylus, is detected using self-capacitance detection method. According to some embodiments, circuitry 50 produces and sends one or more triggering pulses to at least one of the conductive lines 18, and samples output on one or more conductive lines 18 that cross, e.g. are orthogonal to the triggered conductive lines 18, to identify location of finger 46 at the junction area between the conductive line that was triggered and the conductive line that was sampled. Typically, output from each of the cross points is detected by scanning conductive lines 18 along one of the horizontal or vertical axes of digitizer sensor 26 and sampling output from the other one of the axes. Optionally and/or alternatively, circuitry 50 samples conductive line 18 that was triggered and/or conductive lines 18 parallel to the triggered conductive line. Optionally, a self- capacitance touch detection method is used to detect finger and/or passive stylus input.

Typically the triggering pulses and/or signals are analog pulses and/or signals. Typically, the triggering pulses and/or signals are any type of alternating current (AC) signals that are confined to one or more pre-defined frequencies, e.g. a sub-range and/or "frequency window" of about 20 to about 100 KHz, including frequencies between 18 to 200 KHz. Typically, sampling output for finger detection is performed over a time period that is not used for sampling output for stylus detection. Typically, during stylus detection, conductive lines 18 are not triggered. Typically, circuitry 50 provides a relatively low impedance connection while sampling output for stylus detection as compared to a relatively high impedance connection that circuitry 50 uses for sampling output for finger detection. Optionally, a dedicated triggering signal is used for detecting a passive stylus, e.g. a stylus that does not emit a signal.

It is noted that although circuitry 50 is shown as a separate and/or stand alone component, a person of ordinary skill in the art will appreciate that portions of circuitry 50 can be integrated with a processor and/or controller of host and/or some of its designated functionalities can be implemented with processor and/or controller of host 22 and/or are implemented by software installed on host 22. Typically, circuitry 50 can both transmit information to host 22, e.g. coordinates of user interaction, and receive input and/or commands from host 22. Typically, circuitry 50 receives indication from host 22 that stylus 44 has been inserted and/or removed from stylus garage 140. Optionally, circuitry associated with stylus garage 140 is in electrical communication with circuitry 50 and/or circuitry 50 controls operation of switch 138 and/or charging station 136.

Reference is now made to FIG. 2 showing a simplified time line for exemplary sampling periods of the digitizer system during a stylus search and finger operational mode in accordance with some embodiments of the present invention. According to some embodiments of the present invention, the digitizer system supports stylus detection of a stylus that is asynchronous with respect to the digitizer system. Typically, during startup of the digitizer system and/or after a pre-defined time period in which the digitizer system has lost communication with stylus 44, the digitizer system operates in a stylus search and finger mode 300. According to some embodiments of the present invention, stylus search and finger mode 300 is activated on the condition that stylus 44 is outside of stylus garage 140. According to some embodiments of the present invention, during stylus search and finger mode 300, the digitizer system samples output for stylus detection over one or more sampling windows 'S' that are dispersed at different times over a defined refresh cycle 'Ts' to search for a burst signal 43 of stylus 44. Typically, refresh cycle 'Ts' for stylus detection is defined based on a known PRR of stylus 44.

According to some embodiments of the present invention, stylus 44 is operative to emit one or more burst and/or pulse signals 43 over a repetition cycle of stylus 44. Optionally, one or more of burst signals 43 is modulated with information that can be decoded by circuitry 50 and/or host 22. It is noted that only one burst signal 43 per repetition cycle is shown and described herein for simplicity purposes.

According to some embodiments of the present invention, the digitizer system continues to operate in stylus search and finger mode 300 until burst signal 43 is detected over a sampling period 'S'. According to some embodiments of the present invention, once burst signal 43 is detected over sampling windows 'S,' the digitizer system terminates stylus search and finger mode 300 and synchronizes subsequent sampling windows 'S' with a detected timing of signal burst 43. Typically, while the digitizer system is synchronized with stylus signal 43, coordinates of a stylus can be determined based on output from a single sampling window 'S.'

Typically, during stylus search and finger mode, the digitizer system also samples output and/or continues to sample output for finger detection over sampling windows 'F'. According to some embodiments of the present invention, when the digitizer systems detects a finger with a mutual capacitance touch method, a plurality of sampling windows 'F' is required to scan the digitizer sensor 26 before coordinates of finger interaction can be determined. Typically, the digitizer system boosts the report rate for finger detection by including more sampling windows 'F' than sampling windows 'S' . Optionally, the report rate for finger detection is further boosted by increasing the number of sampling windows 'F' required to scan digitizer sensor 26. Optionally, the number of sampling windows 'F' is reduced by simultaneously triggering a group of conductive lines 18, each conductive line 18 of the group with a different frequency. Methods for reducing the number of sampling periods required for scanning a digitizer sensor are described in more details for example in incorporated U.S. Patent No. 7,373,455 and in U.S. Patent No. 8,232,977 entitled "System and Method for Detection with a Digitizer Sensor," both patents incorporated herein by reference for all purposes. In some exemplary embodiments, the digitizer system operates in stylus only mode and finger detection is not performed. In some exemplary embodiments, stylus 44 is synchronous with the digitizer system or is a passive stylus, e.g. does not emit a signal and a stylus search mode is not required.

Reference is now made to FIG. 3 showing a simplified time line for exemplary sampling periods of the digitizer system during a stylus and finger operational mode in accordance with some embodiments of the present invention. According to some embodiments of the present invention, once timing of burst signal 43 is detected, the digitizer system switches its operation to a stylus and finger operational mode 305. According to some embodiments of the present invention, during the stylus and finger operational mode 305, the digitizer system synchronizes sampling window 'S' with timing of burst signal 43. Typically, during stylus and finger operation mode 305, one or more sampling windows 'F' are defined between periods for sampling windows 'S' . In some exemplary embodiments, the digitizer system operates in stylus only mode and finger detection is not performed. Typically, stylus and finger operational mode continues as long as burst signal 43 is detected. Optionally, if burst signal 43 is absent for a pre-defined number of cycles, the digitizer system switches to stylus search and finger mode. According to some embodiments of the present invention, the digitizer system discontinues stylus and finger operational mode and switches to finger only mode responsive to receiving indication that stylus 44 is in stylus garage 140. In some exemplary embodiments, the stylus is a passive stylus that does not emit a signal and the passive stylus is also detected using a mutual capacitive detection method. Optionally, both finger and stylus are detected based on output sampled in a same window. Alternatively, the passive stylus is detected using a self-capacitance detection method.

Reference is now made to FIG. 4 showing a simplified time line for exemplary sampling periods of the digitizer system responsive to indication that the stylus is positioned in the stylus garage in accordance with some embodiments of the present invention. According to some embodiments of the present invention, the digitizer system initiates a finger only detection mode 310 responsive to receiving indication that stylus 44 is in stylus garage 140. According to some embodiments of the present invention, the digitizer system does not sample output for stylus detection during finger only detection mode. In some exemplary embodiments, the digitizer system increases the number of sampling windows 'F' instead, so that the report rate for finger detection is improved. Alternatively, the digitizer system maintains the same report rate, e.g. the same number of sampling windows 'F', and reduces the energy expenditure of the computing device. Optionally, a power management system of computing device 100 provides digitizer system with instructions on how to operate while stylus 44 is in stylus garage 140. The refresh rate may depend on the battery status of the computing device. In some exemplary embodiments, if the digitizer system was operating in stylus only mode, the digitizer sensor suspends all sampling over the duration that the stylus is positioned in the stylus garage.

Reference is now made to FIG. 5 showing a simplified time line for exemplary sampling periods of digitizer system during an enhanced stylus search and finger operational mode in accordance with some embodiments of the present invention. According to some embodiments of the present invention, in response to the digitizer system receiving indication from the computing device that stylus 44 has been removed from stylus garage 140, the digitizer system initiates an enhanced stylus search and finger operational mode 315. Optionally, enhanced stylus search and finger operational mode 315 is initiated only after a pre-defined time period has lapsed, corresponding to an estimated time it would take a user to remove the stylus from the garage and begin using the stylus to interact with the digitizer system. According to some embodiments of the present invention, during enhanced stylus search and finger operational mode 315, the digitizer system increase its rate for searching for a stylus as compared to the rate used in stylus search and finger mode 300 (FIG. 2). According to some embodiments of the present invention, more than one sampling window 'S' for stylus searching is provided per refresh cycle, Ts of stylus detection. Optionally, the refresh rate for finger detection is reduced during this operational mode to allow faster stylus detection. According to some embodiments of the present invention, if stylus 44 is not detected after a pre-defined period of time, the digitizer system switches to stylus search and finger operational mode 310. Typically, once stylus signal 43 is detected, the digitizer system switches to stylus and finger mode 305. In some exemplary embodiments, the digitizer system operates in enhanced stylus search only mode and also does not sample output for finger detection.

Reference is now made to FIG. 6 showing a simplified flow chart of an exemplary method for operating the digitizer system in accordance with some embodiments of the present invention. According to some embodiments of the present invention, the digitizer system may begin operation in a stylus search mode and during this mode searches for a stylus that may be interacting with the digitizer system (block 405). In some exemplary embodiments, the digitizer system also supports finger touch detection and additionally scans the digitizer sensor for finger touch during his period. Optionally, stylus search and finger detection is performed in a stylus search and finger operational mode as discussed herein above for example in reference to FIG. 2. According to some embodiments of the present invention, the digitizer system may query an associated host 22 to determine if the stylus is in stylus garage 140 (block 410). Optionally, host 22 provides indication when the stylus is in stylus garage 140 also without a query by the digitizer system.

According to some embodiments of the present invention, if the stylus is determined to be in stylus garage 140, the digitizer system suspends stylus search (block 415). In some exemplary embodiments, when the digitizer system supports finger touch detection, the digitizer system continues to scan for finger touch interaction during this period. Optionally, digitizer system operates in a finger only detection mode as discussed herein above in reference to FIG. 4. Optionally, the report rate for finger detection is increased during this period.

According to some embodiments of the present invention, as long as the stylus is out of stylus garage 140, digitizer system continues to search for the stylus (block 405) and once the stylus is found (block 440), the digitizer system switches to a stylus track mode for tracking position of the stylus (block 435). Typically, once the stylus is found, the digitizer system synchronizes stylus detection with timing of a signal(s) emitted by the stylus. In some exemplary embodiments, when the digitizer system supports finger touch detection, the digitizer system continues to scan for finger touch interaction during this period. Typically, as long as the digitizer system has indication that the stylus is in the stylus garage, suspension of stylus detection continues. According to some embodiments of the present invention, once the digitizer system receives indication that the stylus has been removed from the garage, the digitizer system switches to an enhanced stylus search mode during which the digitizer system searches for the stylus at a possibly enhanced rate. In some exemplary embodiments, when the digitizer system supports finger touch detection, the digitizer system continues to scan for finger touch interaction during this period. Optionally, the digitizer system operates in an enhanced stylus search and finger operational mode as discussed herein above in reference to FIG. 5.

Reference is now made to FIG. 7 showing a simplified flow chart of an additional exemplary method for operating the digitizer system in accordance with some embodiments of the present invention. According to some embodiments of the present invention, the digitizer system may begin operation in a standard mode (block 605). Typically, during the standard mode, the digitizer system samples output from the digitizer sensor for detecting both stylus and finger interaction. Optionally, during the standard mode, the digitizer system transmits a trigger or synchronizing signal to a stylus. Optionally, during the standard mode, the digitizer system triggers the digitizer sensor at a pre-defined rate and with a pre-defined triggering signal. Optionally, during the standard mode, the digitizer system performs one or more pre-defined processing algorithms on the output sampled, e.g. for palm rejection. In some exemplary embodiments, the digitizer system scans the digitizer sensor finger touches occurring simultaneously on the digitizer sensor can be detected. According to some embodiments of the present invention, the digitizer system may query an associated host to determine if the stylus is in the stylus garage (block 610). Optionally, host provides indication when the stylus is in the stylus garage also without a query by the digitizer system.

According to some embodiments of the present invention, if the stylus is determined to be in the stylus garage, the digitizer system adjusts its operation to operation in a "Stylus in Housing" mode (block 615). Typically, the digitizer system adjusts its operation to operate without stylus interaction. Optionally, in "Stylus in Housing" mode, transmission of a triggering signal to a stylus is suspended. Optionally, stylus detection is suspended. Optionally, refresh rate for finger touch detection is increased. Optionally, one or more parameters of a processing routine is adjusted, e.g. parameters for a routine and/or algorithm to detect palm. According to some embodiments of the present invention, as long as the stylus is in the stylus garage the digitizer system continues to operate in Stylus in Housing" mode (block 620).

According to some embodiments of the present invention, once the digitizer system receives indication that the stylus has been removed from the garage (block 620), the digitizer system switches to operate in a "Stylus Leaving Housing" mode. In some exemplary embodiments, during "Stylus Leaving Housing" mode, the digitizer enhances stylus search and/or detection. Optionally, the digitizer system alters one or more parameters and/or thresholds for detecting finger touch. In some exemplary embodiments, "Stylus Leaving Housing" mode is operated over a pre-defined period of time, after which the digitizer system resumes a standard operation mode (block 605).

Reference is now made to FIGS. 8 A and 8B showing simplified schematic drawings of two exemplary stylus garages associated with a laptop computer in accordance with some embodiments of the present invention. According to some embodiments of the present invention, a computing device 510 has an integrated stylus garage 141 (FIG. 7A), or a computing device 520 is electrically connected to a stylus garage 142. Optionally, computing device 510 or 520 includes a touch screen 145 that supports detection of stylus 44. Optionally, connection with stylus garage 142 can be a tethered connection and/or a wireless connection. Typically, stylus garage 142 can be optionally disconnected from computing device 520.

According to some embodiments of the present invention, stylus garage 141 and/or 142 includes a charging station for charging stylus 44. Optionally, the charging station includes a power supply coil 185 through which stylus 44 is inserted when placed in stylus garage 141 and/or 142. In some exemplary embodiments, computing device 510 or 520 includes a power management integrated circuit (PMIC) that is operated to sense when the stylus 44 is drawing current from the host battery (including leakage current). In some exemplary embodiments, a comparator is used to sense current going into the stylus 44 and the comparator provides indication to the computing device. Optionally, the host tunes the comparator to trigger when the measured current is above a threshold, correlated to the minimum charge current. Optionally, the PMIC, comparator, or the stylus sends an interrupt to the host, which may use an API to provide indication to the digitizer system regarding presence of stylus 44 in stylus garage 141 or 142. Alternatively, stylus garage 141 or 142 includes a sensor and/or switch 128 (FIG. 1) to sense the presence of stylus 44. Optionally, a state of the switch and/or sensor is communicated with a General Purpose Input/Output (GPIO) signal to the host computing platform, or directly to a controller of the digitizer system.

It is noted that although most of the embodiments of been described in reference to stylus and finger detection, a person of ordinary skill in the art will appreciate that methods for finger detection also can also be used for detection other parts of the hand, e.g. such as palm, other parts of the body and/or other capacitive bodies.

It is noted that the digitizer system described herein may be suitable for integration with any computing device that is operable to receive input from a user and includes a display screen, e.g., mobile, desktop, or tabletop computing devices that include, for example, flat panel display screens. Examples of such devices include tablet personal computers (PCs), touch enabled lap-top computers, tabletop computers, personal digital assistants (PDA) or hand held computing devices such as palm pilots, mobile phones, navigation systems, and electronic gaming devices.

The terms "comprises", "comprising", "includes", "including", "having" and their conjugates mean "including but not limited to".

The term "consisting of means "including and limited to".

The term "consisting essentially of" means that the composition, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.

Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

Claims

WHAT IS CLAIMED IS:

1. A method for operating digitizer system that supports position detection of a stylus, the digitizer system integrated with a computing device associated with a stylus housing station, the method comprising:

receiving indication that a stylus is placed in the housing station; and altering operation of the digitizer system in response to receiving the indication that the stylus is placed in the housing station.

2. The method of claim 1 comprising:

suspending stylus detection responsive to receiving the indication that the stylus is placed in the housing station.

3. The method of claim 2 comprising:

receiving indication that the stylus has been removed from the housing station; and

resuming stylus detection responsive to receiving the indication that the stylus has been removed from the housing station.

4. The method according to claim 3, wherein the digitizer system is operative to detect signals emitted by a stylus that is asynchronous with the digitizer system.

5. The method of claim 3 or claim 4 comprising initiating a stylus search operational mode responsive to receiving the indication that the stylus has been removed from the housing station, wherein a signal emitted by the stylus is searched for during the stylus search mode.

6. The method of claim 5, wherein the digitizer system searches for the stylus at an accelerated rate for a pre-defined period after receiving indication that the stylus has been removed from the housing station and then reduced the rate after the pre-defined period has lapsed without signal emitted by the stylus being found.

7. The method according to any one of claims 3-6, comprising switching to a stylus tracking mode responsive to detecting a signal emitted by the stylus with the digitizer system, wherein during the stylus tracking mode coordinates of the stylus on the digitizer system are reported to the computing device.

8. The method according to any one of claims 3-7, wherein the digitizer system is operative to synchronize sampling for stylus detection with timing of signals emitted by the stylus.

9. The method according to any one of claims 1-8, wherein the digitizer system is operative to suspend transmission of a signal to the stylus in response to receiving the indication that the stylus is placed in the housing station.

10. The method according to any one of claims 1-9, wherein the digitizer system is operative to trigger the stylus to emit a signal.

11. The method according to claim 1, wherein the stylus is a conductive pointer that does not emit a signal.

12. The method according to any one of claims 1-11, comprising detecting finger touch interaction with the digitizer system and reporting coordinates of finger touch to the computing device.

13. The method according to claim 12, comprising accelerating a rate of finger touch reporting while stylus detection is suspended.

14. The method according to claim 12 or claim 13, wherein detecting finger touch interaction is based on a mutual capacitance touch method.

15. The method according to any one of claims 1-14, wherein the digitizer system is operative to alter one or more parameters and/or thresholds for detecting finger touch in response to receiving the indication that the stylus is placed in the housing station.

16. The method according to claim 15, wherein the digitizer system is operative to alter one or more parameters and/or thresholds for palm rejection in response to receiving the indication that the stylus is placed in the housing station.

17. The method according to any one of claims 1-16, wherein the digitizer system is a grid based capacitive sensor.

18. The method according to any one of claims 1-17, wherein the housing station includes a sensor for detecting presence of the stylus.

19. The method according to claim 18, wherein output from the sensor is communicated with a general purpose input/output signal to the computing device.

20. The method according to any one of claims 1-19, wherein the housing station includes a charging station for charging a power supply of the stylus.

21. The method according to claim 20, wherein the computing device is operative to sense that the stylus is being charged in the charging station.

22. The method according to any one of claims 19-21, wherein the computing device provides indication to the digitizer system regarding presence of the stylus in the housing station.