U.S. patent number RE48,310 [Application Number 16/197,203] was granted by the patent office on 2020-11-17 for active stylus with passive mutual measurements.
This patent grant is currently assigned to Wacom Co., Ltd.. The grantee listed for this patent is Wacom Co., Ltd.. Invention is credited to Samuel Brunet, Luben H. Hristov, Trond J. Pedersen, Iqbal Sharif.
United States Patent |
RE48,310 |
Brunet , et al. |
November 17, 2020 |
Active stylus with passive mutual measurements
Abstract
An apparatus includes a sense unit operable to sense a plurality
of first signals transmitted on one or more vertical lines and one
or more horizontal lines of a touch sensor, the one or more
vertical lines and the one or more horizontal lines operable to
drive the plurality of first signals. The apparatus also includes a
drive unit operable to transmit, in response to the sense unit
sensing at least one of the plurality of first signals, a second
signal to the one or more vertical lines and the one or more
horizontal lines, the second signal changing an effective charge of
the one or more vertical lines and the one or more horizontal
lines.
Inventors: |
Brunet; Samuel (Cowes,
GB), Hristov; Luben H. (Sofia, BG),
Pedersen; Trond J. (Trondheim, NO), Sharif; Iqbal
(Hampshire, GB) |
Applicant: |
Name |
City |
State |
Country |
Type |
Wacom Co., Ltd. |
Saitama |
N/A |
JP |
|
|
Assignee: |
Wacom Co., Ltd. (Saitama,
JP)
|
Family
ID: |
50029715 |
Appl.
No.: |
16/197,203 |
Filed: |
November 20, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
13586745 |
Aug 15, 2012 |
9563304 |
Feb 7, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F
3/0441 (20190501); G06F 3/0446 (20190501); G06F
3/0416 (20130101); G06F 3/03545 (20130101); G06F
3/0442 (20190501); G06F 3/04162 (20190501); G06F
3/044 (20130101); G06F 3/03545 (20130101) |
Current International
Class: |
G06F
3/041 (20060101); G06F 3/0354 (20130101); G06F
3/044 (20060101) |
Field of
Search: |
;345/173,174,179 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2012/129247 |
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Sep 2012 |
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WO |
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WO 2012/129247 |
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Sep 2012 |
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WO |
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Other References
Rothkopf et al., "Electronic Devices With Flexible Displays," U.S.
Appl. No. 61/454,894, filed Mar. 21, 2011, 49 pages. cited by
applicant .
Myers et al., "Electronic Devices With Concave Displays," U.S.
Appl. No. 61/454,936, filed Mar. 21, 2011, 31 pages. cited by
applicant .
Lynch, "Electronic Devices with Convex Displays," U.S. Appl. No.
61/454,950, filed Mar. 21, 2011, 36 pages. cited by applicant .
U.S. Appl. No. 61/454,936, filed Mar. 21, 2011, Myers. cited by
applicant .
U.S. Appl. No. 61/454,950, filed Mar. 21, 2011, Lynch. cited by
applicant .
U.S. Appl. No. 61/454,894, filed Mar. 21, 2011, Rothkopf. cited by
applicant.
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Primary Examiner: Basehoar; Adam L
Attorney, Agent or Firm: Seed IP Law Group LLP
Claims
What is claimed is:
1. A system comprising: a touch sensor and an apparatus; the
apparatus comprising: a sense unit operable to sense a plurality of
first signals transmitted on one or more vertical lines .[.and.].
.Iadd.and/or .Iaddend.one or more horizontal lines of a touch
sensor, the one or more vertical lines and the one or more
horizontal lines operable to drive the plurality of first signals;
and a drive unit operable to transmit, in response to the sense
unit sensing at least a rising edge .[.and.]. .Iadd.and/or
.Iaddend.a falling edge of one of the plurality of first signals, a
second signal comprising an active high voltage output to the one
or more vertical lines and the one or more horizontal lines, the
second signal changing an effective charge of the one or more
vertical lines and the one or more horizontal lines, the second
signal comprising a modulated waveform; the touch sensor
comprising: a touch-sensor controller operable to acquire the
effective charge of the one or more vertical lines and the one or
more horizontal lines after waiting a predetermined amount of time
for a charge transfer to occur, the charge transfer resulting from
the active high voltage output.Iadd., .Iaddend.the predetermined
amount of time calculated based at least in part on a length of
time required to transmit the active high voltage output from the
drive unit of the apparatus to the one or more vertical lines and
the one or more horizontal lines of the touch sensor; and wherein
the touch-sensor controller includes one or more integrators
operable to, based on the acquired effective charge, compute a
first weighted average of the one or more vertical lines and a
second weighted average of the one or more horizontal lines.
2. The system of claim 1, wherein the sense unit comprises: a high
impedance amplifier operable to buffer and amplify the first
signals; and an edge detector operable to detect an edge of at
least one of the first signals.
3. The system of claim 1, wherein the apparatus further comprises:
a stylus tip; a stylus measure state in which the sensor unit is
operable to sense the first signals on the stylus tip; and a stylus
active state in which the drive unit is operable to drive the
second signal on the stylus tip.
4. The system of claim 1, wherein the sense unit is further
operable to sense .[.a.]. .Iadd.the .Iaddend.plurality of first
signals transmitted on the one or more vertical lines .[.and.].
.Iadd.and/or .Iaddend.the one or more horizontal lines at a
substantially same time.
.[.5. The system of claim 1, wherein the sense unit is further
operable to sense a plurality of first signals transmitted on one
or more vertical lines and one or more horizontal lines of a touch
sensor and the touch sensor is operable to sense the effective
charge on the one or more vertical lines and the one or more
horizontal lines..].
6. The system of claim 1, wherein: the first signals comprise
synchronized signal spikes, and the sense unit is further operable
to sense the first signals by detecting at least one of the
synchronized signal spikes.
7. The system of claim 1, wherein the apparatus further comprises a
stylus tip; wherein the drive unit is further operable to transmit
the second signal by activating a voltage on the stylus tip; and
wherein the drive unit comprises a timing circuit operable to, in
response to the sense unit sensing at least one of the first
signals, activate the voltage.
8. The system of claim 7, wherein the voltage is a high voltage
operable to decrease the effective charge.
9. The system of claim 1, wherein the touch sensor is operable to
determine a location of the apparatus based on the effective charge
of the horizontal lines and the vertical lines.
10. The system of claim 1, wherein the drive unit is further
operable to modulate the second signal in response to one or more
of a detected pressure associated with the apparatus and a detected
tilt angle of the apparatus.
11. An apparatus comprising a controller, wherein the controller is
configured to: while in a line active mode, transmit a plurality of
first signals to an active stylus on a plurality of horizontal
lines .[.and.]. .Iadd.and/or .Iaddend.a plurality of vertical
lines; transition from the line active mode to a line measure mode;
while in the line measure mode, sense an effective charge on the
plurality of horizontal lines and the plurality of vertical lines,
the effective charge responsive to a second signal from the active
stylus, wherein the second signal comprises an active high voltage
output that is transmitted by the active stylus in response to
detecting a rising edge .[.and.]. .Iadd.and/or .Iaddend.a falling
edge of .Iadd.one of .Iaddend.the .Iadd.plurality of .Iaddend.first
.[.signal.]. .Iadd.signals.Iaddend., the second signal further
comprising a modulated waveform; while in the line measure mode,
acquire the effective charge on one or more of the horizontal lines
and one or more of the vertical lines after waiting a predetermined
amount of time for a charge transfer to occur, the charge transfer
resulting from the active high voltage output, the predetermined
amount of time calculated based at least in part on a length of
time required to transmit the active high voltage output from a
drive unit of the active stylus to the one or more .Iadd.of the
.Iaddend.vertical lines and the one or more .Iadd.of the
.Iaddend.horizontal lines of the apparatus; and based on the
acquired effective charge, compute, by one or more integrators, a
first weighted average of the one or more .Iadd.of the
.Iaddend.vertical lines and a second weighted average of the one or
more .Iadd.of the .Iaddend.horizontal lines.
12. The apparatus of claim 11, further operable to transmit the
plurality of first signals on the plurality of vertical lines
.[.and.]. .Iadd.and/or .Iaddend.the plurality of horizontal lines
at a substantially same time.
13. The apparatus of claim 11, wherein: the first signals comprise
synchronized signal spikes; and the active stylus is operable to
sense the first signals by detecting at least one of the
synchronized signal spikes.
14. The apparatus of claim 11: further operable to receive a high
voltage signal from the active stylus; and wherein the high voltage
signal decreases the effective charge of at least one of the
horizontal lines and at least one of the vertical lines.
15. The apparatus of claim 11, further operable to determine a
location of the active stylus based on the effective charge of the
plurality of horizontal lines and the plurality of vertical
lines.
16. The apparatus of claim 11, further operable to: detect a
modulated effective charge on one or more of the horizontal lines
and one or more of the vertical lines; and determine one or more of
a tilt angle of the active stylus and a pressure associated with
the active stylus.
17. A method, comprising: transmitting a synchronized first signal
on .[.each of a plurality.]. .Iadd.at least one .Iaddend.of
horizontal lines and .[.each of a plurality.]. of vertical lines of
a touch screen device, wherein the synchronized first signal is
sensed on a stylus tip of an active stylus; sensing an effective
charge of the .[.plurality of.]. horizontal lines and .[.the
plurality of.]. the vertical lines, wherein the active stylus
activates an active high voltage output on the stylus tip in
response to detecting a rising edge .[.and.]. .Iadd.and/or
.Iaddend.a falling edge of the synchronized first signal, the
active high voltage operable to change the effective charge on one
or more of the horizontal lines and one or more of the vertical
lines, the active high voltage comprising a modulated waveform;
acquiring the effective charge of the .[.plurality of.]. horizontal
lines and the .[.plurality of the.]. vertical lines after waiting a
predetermined amount of time for a charge transfer to occur, the
charge transfer resulting from the active high voltage output, the
predetermined amount of time calculated based at least in part on a
length of time required to transmit the active high voltage output
from a drive unit of the active stylus to .Iadd.the .Iaddend.one or
more .Iadd.of the .Iaddend.vertical lines and .Iadd.the
.Iaddend.one or more .Iadd.of the .Iaddend.horizontal lines of the
touch screen device; and based on the acquired effective charge,
determining a location of the active stylus using one or more
integrators, wherein the one or more integrators compute a first
weighted average of the .[.plurality of.]. vertical lines and a
second weighted average of the .[.plurality of.]. horizontal
lines.
18. The method of claim 17, further comprising: transmitting the
synchronized first signal while a touch-sensor controller is in a
line active mode; and transitioning the touch-sensor controller to
a line measure mode.
19. The method of claim 17, wherein the synchronized first signal
comprises a synchronized signal spike and the active stylus is
operable to sense the synchronized first signal by detecting the
synchronized signal spike.
20. The method of claim 17, further comprising detecting one or
more of a tilt angle of the active stylus and a pressure associated
with the active stylus.
21. A method, comprising: sensing a synchronized first signal on a
stylus tip of an active stylus, wherein the synchronized first
signal is transmitted on .[.each of a plurality.]. .Iadd.at least
one .Iaddend.of horizontal lines and .[.each of a plurality of.].
vertical lines of a touch screen device; and activating an active
high voltage on the stylus tip in response to detecting a rising
edge .[.and.]. .Iadd.and/or .Iaddend.a falling edge of the
synchronized first signal, the active high voltage operable to
change an effective charge on one or more of the horizontal lines
and one or more of the vertical lines, the active high voltage
comprising a modulated waveform; wherein the touch screen device:
senses the effective charge of the .[.plurality of.]. horizontal
lines and the .[.plurality of.]. vertical lines, acquires the
effective charge of the .[.plurality of.]. horizontal lines and the
.[.plurality of.]. vertical lines after waiting a predetermined
amount of time for a charge transfer to occur, the charge transfer
resulting from the active high voltage output, the predetermined
amount of time calculated based at least in part on a length of
time required to transmit the active high voltage output from a
drive unit of the active stylus to .Iadd.the .Iaddend.one or more
.Iadd.of the .Iaddend.vertical lines and .Iadd.the .Iaddend.one or
more .Iadd.of the .Iaddend.horizontal lines of the touch screen
device, and based on the acquired effective charge, determines a
location of the active stylus using one or more integrators,
wherein the one or more integrators compute a first weighted
average of the .[.plurality of.]. vertical lines and a second
weighted average of the .[.plurality of.]. horizontal lines.
22. A computer-readable non-transitory storage medium embodying
logic configured when executed to: transmit a synchronized first
signal on .[.each of a plurality.]. .Iadd.at least one .Iaddend.of
horizontal lines and .[.each of a plurality of.]. vertical lines of
a touch screen device, wherein the synchronized first signal is
sensed on a stylus tip of an active stylus; sense an effective
charge of the .[.plurality of.]. horizontal lines and .[.the
plurality of.]. the vertical lines, wherein the active stylus
activates an active high voltage output on the stylus tip in
response to detecting a rising edge .[.and.]. .Iadd.and/or
.Iaddend.a falling edge of the synchronized first signal, the
active high voltage operable to change the effective charge on one
or more of the horizontal lines and one or more of the vertical
lines, the active high voltage comprising a modulated waveform;
acquire the effective charge of the .[.plurality of.]. horizontal
lines and .[.the plurality of.]. the vertical lines after waiting a
predetermined amount of time for a charge transfer to occur, the
charge transfer resulting from the active high voltage output, the
predetermined amount of time calculated based at least in part on a
length of time required to transmit the active high voltage output
from a drive unit of the active stylus to the one or more .Iadd.of
the .Iaddend.vertical lines and the one or more .Iadd.of the
.Iaddend.horizontal lines of the touch screen device.[.:.]..Iadd.;
.Iaddend.and based on the acquired effective charge, determine a
location of the active stylus using one or more integrators,
wherein the one or more integrators compute a first weighted
average of the .[.plurality of.]. vertical lines and a second
weighted average of the .[.plurality of.]. horizontal lines.
Description
TECHNICAL FIELD
This disclosure relates generally to touch screen technology.
BACKGROUND
A touch sensor may detect the presence and location of a touch or
the proximity of an object (such as a user's finger or a stylus)
within a touch-sensitive area of the touch sensor overlaid on a
display screen, for example. In a touch-sensitive-display
application, the touch sensor may enable a user to interact
directly with what is displayed on the screen, rather than
indirectly with a mouse or touch pad. A touch sensor may be
attached to or provided as part of a desktop computer, laptop
computer, tablet computer, personal digital assistant (PDA),
smartphone, satellite navigation device, portable media player,
portable game console, kiosk computer, point-of-sale device, or
other suitable device. A control panel on a household or other
appliance may include a touch sensor.
There are a number of different types of touch sensors, such as
(for example) resistive touch screens, surface acoustic wave touch
screens, and capacitive touch screens. Herein, reference to a touch
sensor may encompass a touch screen, and vice versa, in particular
embodiments. When an object touches or comes within proximity of
the surface of the capacitive touch screen, a change in capacitance
may occur within the touch screen at the location of the touch or
proximity. A touch-sensor controller may process the change in
capacitance to determine its position on the touch screen.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an example touch sensor.
FIG. 2 illustrates an example active stylus with touch sensor
device.
FIG. 3 illustrates an example active stylus.
FIG. 4 illustrates an example method of communication between an
active stylus and a touch sensor device.
FIG. 5 illustrates an example timing diagram for communicating
between an active stylus and a touch sensor device.
DESCRIPTION OF EXAMPLE EMBODIMENTS
In particular implementations of a touch sensor, the touch sensor
may be configured to detect and/or track the location of an active
stylus in proximity to the touch sensor. Example embodiments of a
touch sensor and active stylus are herein described. In particular
embodiments, the active stylus may interact with a touch sensor
using passive mutual measurements by the touch sensor. The touch
sensor may operate in two modes, one in which the touch sensor
drives a signal on the touch sensor's horizontal and vertical
electrodes lines and one in which the touch sensor takes passive
mutual measurements of the horizontal and vertical electrodes. The
active stylus may similarly operate in two modes, one in which the
active stylus detects a drive signal on the active stylus tip, and
one in which the active stylus activates a voltage on the active
stylus tip. When the active stylus detects the drive signal, the
active stylus may, in response, activate the voltage. After
transmitting the drive signal, the touch sensor may begin to take
passive mutual measurements of the horizontal and vertical
electrodes. Based on the effect of the voltage on the passive
mutual measurements, the touch sensor may determine the location of
the active stylus relative to an intersection of a horizontal
electrode and vertical electrode. A more detailed description of
example embodiments of a touch sensor and active stylus, including
technical advantages of various embodiments, are described below
with respect to FIGS. 1 to 5.
FIG. 1 illustrates an example touch sensor 10 with an example
touch-sensor controller 12. Touch sensor 10 and touch-sensor
controller 12 may detect the presence and location of a touch or
the proximity of an object within a touch-sensitive area of touch
sensor 10. Herein, reference to a touch sensor may encompass both
the touch sensor and its touch-sensor controller, in particular
embodiments. Similarly, reference to a touch-sensor controller may
encompass both the touch-sensor controller and its touch sensor, in
particular embodiments. Touch sensor 10 may include one or more
touch-sensitive areas, in particular embodiments. 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. Herein, reference to a
touch sensor may encompass both the electrodes of the touch sensor
and the substrate(s) that they are disposed on, in particular
embodiments. Alternatively, in particular embodiments, reference to
a touch sensor may encompass the electrodes of the touch sensor,
but not the substrate(s) that they are disposed on.
An electrode (whether a ground electrode, a guard electrode, a
drive electrode, or a sense electrode) may be an area of conductive
material forming a shape, such as for example a disc, square,
rectangle, thin line, other suitable shape, or suitable combination
of these. One or more cuts in one or more layers of conductive
material may (at least in part) create the shape of an electrode,
and the area of the shape may (at least in part) be bounded by
those cuts. In particular embodiments, the conductive material of
an electrode may occupy approximately 100% of the area of its
shape. As an example and not by way of limitation, an electrode may
be made of indium tin oxide (ITO) and the ITO of the electrode may
occupy approximately 100% of the area of its shape (sometimes
referred to as 100% fill), in particular embodiments. In particular
embodiments, the conductive material of an electrode may occupy
substantially less than 100% of the area of its shape. As an
example and not by way of limitation, an electrode may be made of
fine lines of metal or other conductive material (FLM), such as for
example copper, silver, or a copper- or silver-based material, and
the fine lines of conductive material may occupy approximately 5%
of the area of its shape in a hatched, mesh, or other suitable
pattern. Herein, reference to FLM encompasses such material, in
particular embodiments. Although this disclosure describes or
illustrates particular electrodes made of particular conductive
material forming particular shapes with particular fill percentages
having particular patterns, this disclosure contemplates any
suitable electrodes made of any suitable conductive material
forming any suitable shapes with any suitable fill percentages
having any suitable patterns.
In particular embodiments, the shapes of the electrodes (or other
elements) of a touch sensor may constitute in whole or in part one
or more macro-features of the touch sensor. One or more
characteristics of the implementation of those shapes (such as, for
example, the conductive materials, fills, or patterns within the
shapes) may constitute in whole or in part one or more
micro-features of the touch sensor. One or more macro-features of a
touch sensor may determine one or more characteristics of its
functionality, and one or more micro-features of the touch sensor
may determine one or more optical features of the touch sensor,
such as transmittance, refraction, or reflection.
A mechanical stack may contain the substrate (or multiple
substrates) and the conductive material forming the drive or sense
electrodes of touch sensor 10. As an example and not by way of
limitation, the mechanical stack may include a first layer of
optically clear adhesive (OCA) beneath a cover panel. The cover
panel may be clear and made of a resilient material suitable for
repeated touching, such as for example glass, polycarbonate, or
poly(methyl methacrylate) (PMMA). This disclosure contemplates any
suitable cover panel 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 another suitable
material, similar to the substrate with the conductive material
forming the drive or sense electrodes). As an alternative, in
particular embodiments, a thin coating of a dielectric material may
be applied instead 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 making up 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 to a
display of a device including touch sensor 10 and touch-sensor
controller 12. As an example only and not by way of limitation, the
cover panel may have a thickness of approximately 1 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 this disclosure describes a particular mechanical
stack with a particular number of particular layers made of
particular materials and having particular thicknesses, this
disclosure contemplates any suitable mechanical stack with any
suitable number of any suitable layers made of any suitable
materials and having any suitable thicknesses. As an example and
not by way of limitation, in particular embodiments, a layer of
adhesive or dielectric may replace the dielectric layer, second
layer of OCA, and air gap described above, with there being no air
gap to the display.
One or more portions of the substrate of touch sensor 10 may be
made of polyethylene terephthalate (PET) or another suitable
material. This disclosure contemplates any suitable substrate with
any suitable portions made of any suitable material. In particular
embodiments, the drive or sense electrodes in touch sensor 10 may
be made of ITO in whole or in part. In particular embodiments, the
drive or sense electrodes in touch sensor 10 may be made of fine
lines of metal or other conductive material. As an example and not
by way of limitation, one or more portions of the conductive
material may be copper or copper-based and have a thickness of
approximately 5 .mu.m or less and a width of approximately 10 .mu.m
or less. As another example, one or more portions of the conductive
material may be silver or silver-based and similarly have a
thickness of approximately 5 .mu.m or less and a width of
approximately 10 .mu.m or less. This disclosure contemplates any
suitable electrodes made of any suitable material.
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 near each other, but not make electrical
contact with each other. Instead, the drive and sense electrodes
may be capacitively coupled to each other across a space between
them. A pulsed 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 charge induced may be
susceptible to external influence (such as a touch or the proximity
of an object). When an object touches or comes within proximity of
the capacitive node, a change in capacitance may occur at the
capacitive node and touch-sensor controller 12 may measure the
change in capacitance. By measuring changes in capacitance
throughout the array, touch-sensor controller 12 may determine the
position of the touch or proximity within the touch-sensitive
area(s) of touch sensor 10.
In a self-capacitance implementation, touch sensor 10 may include
an array of electrodes of a single type that may each form a
capacitive node. When an object touches or comes within proximity
of 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, for example, as a change in the amount of
charge needed to raise the voltage at the capacitive node by a
pre-determined amount. As with a mutual-capacitance implementation,
by measuring changes in capacitance throughout the array,
touch-sensor controller 12 may determine the position of the touch
or proximity within the touch-sensitive area(s) of touch sensor 10.
This disclosure contemplates any suitable form of capacitive touch
sensing, in particular embodiments.
In particular embodiments, one or more drive electrodes may
together form a drive line running horizontally or vertically or in
any suitable orientation. Similarly, one or more sense electrodes
may together form a sense line running horizontally or vertically
or in any suitable orientation. In particular embodiments, drive
lines may run substantially perpendicular to sense lines. Herein,
reference to a drive line may encompass one or more drive
electrodes making up the drive line, and vice versa, in particular
embodiments. Similarly, reference to a sense line may encompass one
or more sense electrodes making up the sense line, and vice versa,
in particular embodiments.
Touch sensor 10 may have drive and sense electrodes disposed 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 space between them may form a capacitive node. For a
self-capacitance implementation, electrodes of only a single type
may be disposed in a pattern on a single substrate. In addition or
as an alternative to having drive and sense electrodes disposed in
a pattern on one side of a single substrate, touch sensor 10 may
have drive electrodes disposed in a pattern on one side of a
substrate and sense electrodes disposed in a pattern on another
side of the substrate. Moreover, touch sensor 10 may have drive
electrodes disposed in a pattern on one side of one substrate and
sense electrodes disposed in a pattern on one 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 the
sense electrode "cross" or come nearest each other in their
respective planes. The drive and sense electrodes do not make
electrical contact with each other--instead they are capacitively
coupled to each other across a dielectric at the intersection.
Although this disclosure describes particular configurations of
particular electrodes forming particular nodes, this disclosure
contemplates any suitable configuration of any suitable electrodes
forming any suitable nodes. Moreover, this disclosure contemplates
any suitable electrodes disposed on any suitable number of any
suitable substrates in any suitable patterns.
As described above, a change in capacitance at a capacitive node of
touch sensor 10 may indicate a touch or proximity input at the
position 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 other components (such one or more
central processing units (CPUs)) of a device that includes touch
sensor 10 and touch-sensor controller 12, which may respond to the
touch or proximity input by initiating a function of the device (or
an application running on the device). Although this disclosure
describes a particular touch-sensor controller having particular
functionality with respect to a particular device and a particular
touch sensor, this disclosure contemplates any suitable
touch-sensor controller having any suitable functionality with
respect to any suitable device and any suitable touch sensor.
Touch-sensor controller 12 may be one or more integrated circuits
(ICs), such as for example general-purpose microprocessors,
microcontrollers, programmable logic devices or arrays,
application-specific ICs (ASICs). In particular embodiments,
touch-sensor controller 12 comprises analog circuitry, digital
logic, and digital non-volatile memory. In particular embodiments,
touch-sensor controller 12 is disposed on a flexible printed
circuit (FPC) bonded to the substrate of touch sensor 10, as
described below. The FPC may be active or passive, in particular
embodiments. In particular embodiments, multiple touch-sensor
controllers 12 are disposed on the FPC. Touch-sensor controller 12
may include a processor unit, a drive unit, a sense unit, and a
storage unit. The drive unit may supply drive signals to the drive
electrodes of touch sensor 10. The sense unit may sense charge at
the capacitive nodes of touch sensor 10 and provide measurement
signals to the processor unit representing capacitances at the
capacitive nodes. The processor unit may control the supply of
drive signals to the drive electrodes by the drive unit and process
measurement signals from the sense 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 may
also track changes in the position of a touch or proximity input
within the touch-sensitive area(s) of touch sensor 10. The storage
unit may store programming for execution by the processor unit,
including programming for controlling the drive unit to supply
drive signals to the drive electrodes, programming for processing
measurement signals from the sense unit, and other suitable
programming, in particular embodiments. Although this disclosure
describes a particular touch-sensor controller having a particular
implementation with particular components, this disclosure
contemplates any suitable touch-sensor controller having any
suitable implementation with any suitable components.
Tracks 14 of conductive material disposed on the substrate of touch
sensor 10 may couple the drive or sense electrodes of touch sensor
10 to connection pads 16, also disposed on the substrate of touch
sensor 10. As described below, connection pads 16 facilitate
coupling of tracks 14 to touch-sensor controller 12. Tracks 14 may
extend into or around (e.g. at the edges of the touch-sensitive
area(s) of touch sensor 10. Particular tracks 14 may 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 may supply drive signals to the drive
electrodes. Other tracks 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 charge at the capacitive nodes of touch sensor 10.
Tracks 14 may be made of fine lines of metal or other conductive
material. As an example and not by way of limitation, the
conductive material of tracks 14 may be copper or copper-based and
have a width of approximately 100 .mu.m or less. As another
example, the conductive material of tracks 14 may be silver or
silver-based and have a width of approximately 100 .mu.m or less.
In particular embodiments, tracks 14 may be made of ITO in whole or
in part in addition or as an alternative to fine lines of metal or
other conductive material. Although this disclosure describes
particular tracks made of particular materials with particular
widths, this disclosure contemplates any suitable tracks made of
any suitable materials with any suitable widths. In addition to
tracks 14, touch sensor 10 may include one or more ground lines
terminating at a ground connector (which may be a connection pad
16) at an edge of the substrate of touch sensor 10 (similar to
tracks 14).
Connection pads 16 may be located along one or more edges of the
substrate, outside the touch-sensitive area(s) of touch sensor 10.
As described above, touch-sensor controller 12 may be on an FPC.
Connection pads 16 may be made of the same material as tracks 14
and may be bonded to the FPC using an anisotropic conductive film
(ACF). Connection 18 may include conductive lines on the FPC
coupling touch-sensor controller 12 to connection pads 16, in turn
coupling touch-sensor controller 12 to tracks 14 and to the drive
or sense electrodes of touch sensor 10. In another embodiment,
connection pads 16 may be connected to an electro-mechanical
connector (such as a zero insertion force wire-to-board connector);
in this embodiment, connection 18 may not need to include an FPC.
This disclosure contemplates any suitable connection 18 between
touch-sensor controller 12 and touch sensor 10.
Touch sensor 10 may interact with a touch object such as an active
stylus in any suitable manner. A particular active stylus may be
configured to cause a change in capacitance at a capacitive node of
touch sensor 10. The change in capacitance induced by the active
stylus may mimic a touch by, for example, a human finger.
Accordingly, when the processor causes the drive unit to supply
drive signals to the one or more of the drive electrodes, an active
stylus may detect the pulse and respond by injecting a charge at a
capacitive node in proximity to the active stylus. The touch-sensor
controller 12 may measure the change in capacitance to detect
and/or track the location of the active stylus.
In a particular implementation of touch sensor 10, touch-sensor
controller 12 may successively control pulses on horizontal drive
lines such that a given horizontal drive line may pulse at a given
time. The active stylus may detect the edge of the pulse on the
given horizontal drive line and may determine an amplitude of the
pulse induced in a tip of the active stylus. In response, the
active stylus may transmit a high voltage pulse on its stylus tip.
The active stylus may modulate the amplitude of the pulse based on
the amplitude of the pulse induced in the active stylus tip by the
given horizontal drive line. The pulse transmitted by the active
stylus tip may reduce the effective charge of capacitive nodes in
proximity to the active stylus. The touch-sensor controller may
detect the resulting effective charge on the vertical sense lines,
and by coordinating the known location of the horizontal drive line
pulse with the effective charge on the vertical sense lines,
determine a location of active stylus.
Modulation of the pulse transmitted by the active stylus may be
detected by the touch-sensor controller to facilitate determining
the location of the active stylus. For example if the active stylus
is moving in a direction parallel with the vertical sense lines, a
modulated signal responsive to the amplitude of the drive line
signal detected by the active stylus may allow the touch-screen
controller to determine the active stylus's relative vertical
distance from a given horizontal drive line. Modulating the signal
output by the active stylus may increase the accuracy of the
touch-sensor controller 12. In order to accomplish this, the active
stylus may include a detection circuit that detects the amplitude
of drive line pulses and modulates the pulse output on its stylus
tip responsive to the amplitude of the detected drive line
pulse.
In some implementations, however, it may be desirable to use such a
amplitude detection and modulation circuit in the active stylus for
other purposes, or, to remove it entirely. Described below with
respect to FIGS. 2 to 5 is an active stylus that may interact with
a touch sensor using passive mutual measurements by the touch
sensor. In an implementation with passive mutual measurements, an
active stylus may, in some embodiments, be provided that does not
include circuitry to detect amplitude of a drive line signal and
modulate the amplitude of pulse output in response to the amplitude
of the detected drive line signal. Alternatively or in addition,
the active stylus herein described may modulate its output to
transmit other information to the touch-sensor controller 12, such
as pressure information and/or tilt angle information.
FIG. 2 illustrates an example active stylus 30 with touch sensor 10
and touch-sensor controller 12. Touch-sensor controller 12 may
detect a location of active stylus 30 using passive mutual
measurements. Touch-sensor 10 includes an array of drive and sense
electrodes X.sub.0 . . . X.sub.N and Y.sub.0 . . . Y.sub.N.
Horizontal lines X.sub.0 . . . X.sub.N may represent electrodes
that are configured to operate as drive lines and sense lines.
Vertical electrodes Y.sub.0 . . . Y.sub.N may represent electrodes
that are configured to operate as drive lines and sense lines. It
should be understood, however that while pictured as having a
particular orientation and geometry, touch sensor 10 may be
configured with any appropriate pattern and geometry, including the
aforementioned hatched and/or mesh patterns.
Active stylus 30 includes a stylus tip 34 and an electronic circuit
32. Stylus tip 34 of active stylus 30 represents any suitable
combination of components and/or circuitry to sense a pulse signal
transmitted on one or more of horizontal lines X.sub.0 . . .
X.sub.N and/or vertical lines Y.sub.0 . . . Y.sub.N. Electronic
circuit 32 represents any suitable combination of components and/or
circuitry to detect the pulse signal sensed by stylus tip 34 and
respond by transmitting an appropriate signal on stylus tip 34. In
some embodiments, electronic circuit 32 includes a timing circuit
and other components appropriate to synchronize the output of the
appropriate signal on stylus tip 34 such that the signal output by
stylus tip 34 occurs at a time expected by touch-sensor controller
12. A more detailed embodiment of active stylus 30 is explained
below with respect to FIG. 3.
Active stylus 30 may be capacitively and/or galvanically coupled to
an operator interacting with the touch screen. The operator may be
capacitively (C.sub.G1) and/or galvanically coupled to ground.
Touch-sensor controller 12 may also be capacitively (C.sub.G2)
and/or galvanically coupled to ground. Accordingly, a pulse
generated by stylus tip 34 and/or electronic circuit 32 may be
received on the electrodes of touch sensor 10 such as one or more
of horizontal lines X.sub.0 . . . X.sub.N and one or more of
vertical lines Y.sub.0 . . . Y.sub.N. Active stylus 30 also may be
capacitively coupled to one or more electrodes of touch sensor 10
that are in proximity to stylus tip 34. As illustrated, active
stylus 30 is in proximity to horizontal line X.sub.0 and vertical
line Y.sub.1, which results in capacitances of C.sub.X0 and
C.sub.Y1. Due to charge balance, a voltage pulse on stylus tip may
result in a corresponding change in charge of charge on the
electrodes of touch sensor 10. For example, an appropriate high
voltage pulse may result in a decrease in charge on the electrodes
X.sub.0 and Y.sub.1.
In operation, touch-sensor controller 12 may control horizontal
lines X.sub.0 . . . X.sub.N and vertical lines Y.sub.0 . . .
Y.sub.N according to particular modes of operation. In one mode,
horizontal lines X.sub.0 . . . X.sub.N and vertical lines Y.sub.0 .
. . Y.sub.N may act as drive lines. This mode may be referred to as
a line active mode. In a second mode, X.sub.0 . . . X.sub.N and
vertical lines Y.sub.0 . . . Y.sub.N may act as sense lines. This
mode may be referred to as a line measure mode.
While in the line active mode, touch-sensor controller 12 may
transmit a drive signal 70 on all or substantially all of
horizontal lines X.sub.0 . . . X.sub.N and vertical lines Y.sub.0 .
. . Y.sub.N. In some embodiments, touch-sensor controller 12 may
select a subset of X.sub.0 . . . X.sub.N and vertical lines Y.sub.0
. . . Y.sub.N on which to transmit drive signal 70. Drive signals
70 transmitted on the electrodes of touch sensor 10 may be
synchronized signal spikes. The drive signals 70 may be transmitted
at substantially the same time and/or have substantially the same
waveform on each of the lines. Thus, each of drive signals 70 may
collectively act as a single synchronized pulse signal. Moreover,
in some embodiments, drive signals 70 may be used as a
synchronization signal that triggers the timing sequence between
touch-sensor controller 12 and the timing circuit of active stylus
30.
In response to detecting the drive signal 70, active stylus 30
transitions to an active output mode and transmits a pulse on
stylus tip 34. Meanwhile, after transmitting the drive signals on
horizontal lines X.sub.0 . . . X.sub.N and vertical lines Y.sub.0 .
. . Y.sub.N, touch-sensor controller 12 may transition the
electrodes to the line measure mode. At such time, all the sense
lines may be floated. If, for example, touch-sensor controller 12
does not measure on all lines, the non-measured lines should be
held to ground or some constant voltage.
While in the line measure mode, touch-sensor controller acquires
the effective charge on each of the X and Y lines. The charge may
be acquired after a predetermined amount of time. The predetermined
amount of time may be calculated to allow active stylus 30 enough
time to acquire drive signal 70, ready the voltage pulse on stylus
tip 34, and/or allow the effective charge to be transferred to
electrodes of touch-sensor 10 that are in proximity to the active
stylus tip 34, such as X.sub.0 and Y.sub.1 in the illustration.
More detailed embodiments of example timing sequences between
active stylus 30 and touch-sensor controller 12 are discussed below
with respect to FIGS. 4 and 5.
As a result of the pulse on stylus tip 34 of active stylus 30, the
resulting charge on electrodes proximate to stylus tip 34 may
decrease. In the illustrated embodiment, active stylus 30 is
located near the intersection of the X.sub.0 and Y.sub.1 lines.
Graph 72 illustrates the resulting decrease in charge on the
X.sub.0 line, while graph 74 illustrates the resulting decrease in
charge on the Y.sub.1 line. The decrease in effective charge may be
determined by touch-sensor controller 12 in order to determine the
location of active stylus 30.
After a fixed amount of time after drive signal 70 is transmitted,
touch-sensor controller 12 may determine to acquire the charge on
horizontal lines X.sub.0 . . . X.sub.N and vertical lines Y.sub.0 .
. . Y.sub.N. The charges on the lines may be acquired and/or
analyzed in any suitable manner. For example, touch-sensor
controller 12 may include and/or be connected to one or more
integrators that compute a weighted average of signals on the X
lines and a weighted average of signals on the Y lines. The
weighted averages may be analyzed to determine an X.sub.n, Y.sub.m
location of active stylus 30. After a fixed amount of time behind
the negative edge of drive signal 70, while the sense lines may be
floating, integrators of the acquisition circuit of controller 12
may be switched on and the transferred charge from the stylus may
be transferred to the integrator capacitance. Once the integration
is completed, the sense line may be connected to ground. In some
embodiments the X lines may integrated by one integrator and the Y
lines may be integrated by another integrator.
Another method of acquiring the charge may include measuring the
charges on each of the lines by detecting a spike in voltage on the
X-Y lines. Another example is using a balanced position method to
locate the place between the left sum of signals and right sum of
signals becomes minimum.
After the pulse is acquired during the measure line state and
location of active stylus 30 determined, touch-sensor controller 12
may transition the horizontal and vertical lines back to an active
line state in which the drive signal 70 is transmitted and the
process may repeat.
As a result of the ability to measure on the horizontal and
vertical lines of touch sensor 10, any requirement to modulate the
signal in response to the amplitude of the drive signal may be
reduced and/or eliminated. Accordingly, a technical advantage may
include the ability to produce an active stylus without modulation
hardware, resulting in lower costs and higher efficiency. This may
allow an active stylus to have reduced power consumption and/or
greater battery life than other active stylus solutions. Another
technical advantage may be the ability to modulate the output
signal of an active stylus in order to convey other information to
touch-sensor controller 12, such as a detected tilt angle of an
active stylus, pressure associated with an active stylus, and/or
other information associated with an active stylus.
FIG. 3 illustrates an example active stylus 30. As illustrated,
active stylus 30 includes an electronic circuit 32 and stylus tip
34. Active stylus 30 may additionally include any number of
buttons, sliders, indicators, and/or other components operable to
provide human machine interaction. For example, active stylus 30
may include a angle sensor to detect tilt angle and/or a pressure
sensor to detect pressure associated with the active stylus 30,
such as the pressure of active stylus tip 34 against touch sensor
10 or other object. Generally, active stylus 30 detects a drive
signal transmitted from touch sensor 10, and, in response,
transmits an output signal on stylus tip 34.
Electronic circuit 32 includes a sense unit 36 and a drive unit 38.
Sense unit 36 detects a drive signal sensed by stylus tip 34, while
drive unit 38 transmits an output signal on stylus tip 34. Sense
unit 36 includes high impedance amplifier 40 coupled to an edge
detector 42. Sense unit 36 is used to detect drive signals
transmitted on the horizontal and/or vertical electrodes of touch
sensor 10.
Drive unit 38 includes a timing circuit 44, an oscillator 46, a
high voltage source 48, and a battery 50. Timing circuit 44 is
coupled to edge detector 42, oscillator 46, and high voltage source
48. Timing circuit 44 is connected to a switch contact of switching
device 52. Timing circuit 44 controls the timing various events
within active stylus 30, including its modes of operations and/or
timing sequence. In some embodiments, timing circuit 44 may include
a modulation circuit operable to modulate the output of high
voltage source 48. Oscillator 46 may provide a clock input for
timing circuit 44. Timing circuit 44 may be operable to modulate
the output of high voltage source 48 in order to transmit modulated
signals to touch-sensor controller 12 representative of information
received from a tilt, pressure, and/or other sensor associated with
active stylus 30.
High voltage source 48 represents a circuit operable to convert a
low-voltage battery source to a high-voltage pulse output on active
stylus tip 34. For example, in some embodiments, high voltage
source 48 may output a voltage of up to 20V. Although a particular
voltage is disclosed, it should be understood that any voltage
operable to decrease the effective charge of horizontal and
vertical lines in proximity to active stylus tip 34 may be used.
Switching device 52 may be operable to selectively output the high
voltage source on stylus tip 34 in response to signals received
from timing circuit 44.
In operation, active stylus 30 may operate according to various
modes of operation, including a measure mode and an active output
mode. While active stylus 30 is in the measure mode, high impedance
amplifier 40 may detect one or more signals transmitted, for
example, by the horizontal and vertical lines of a touch sensor 10.
The signals, may, for example be synchronized signal spikes
transmitted on horizontal lines X.sub.0 . . . X.sub.N and vertical
lines Y.sub.0 . . . Y.sub.N. The synchronized signal spikes may, as
explained above, collectively form a single signal, such as a
synchronization pulse, that may be configured to synchronize the
timing of the communications between touch-sensor controller 12 and
active stylus 30.
Edge detector 42 may detect an edge of signal or signals
transmitted by touch-sensor controller 12. Edge detector 42 may, in
some embodiments detect a positive edge and/or negative edge of a
synchronization pulse. In response to one or more edges being
detected, edge detector 42 may transmit a signal to timing circuit
44. Timing circuit 44, in response to an edge being detected, may
transition the state of active stylus 30 to the active output state
in which a high voltage may be output on stylus tip 34. Timing
circuit 44 may determine when to activate high voltage source 48
according to a predetermined timing sequence.
In operation, when active stylus 30 is in a measure mode, high
impedance amplifier 40 may detect the drive signal 70, such as a
synchronization pulse, transmitted by touch-sensor controller 12 on
horizontal lines X.sub.0 . . . X.sub.N and vertical lines Y.sub.0 .
. . Y.sub.N. Edge detector 42 may detect the positive arising
and/or falling edge of the drive signal 70 and in response, may
transmit a signal to timing circuit according to the rising and/or
falling edge. In response, timing circuit 44 may ready active
stylus 30 for the active output mode in which high voltage source
48 is transmitted to active stylus tip 34 by turning on and/or
activating switching device 52. During the time in which the high
voltage is output on active stylus tip 34, timing circuit may
modulate the output in order to transmit information associated
with one or more sensors of active stylus 30. By modulating the
height of the active output voltage, data may be exchanged between
active stylus 30 and touch-sensor controller 12. For example,
active stylus 30 may transmit data representative of a tilt angle
of active stylus 30, of a pressure associated with active stylus
30, of one or more buttons and/or sliders being activated, and/or
other appropriate information. After a predetermined amount of
time, timing circuit 44 may turn off and/or deactivate switch 52.
Timing circuit 44 may then ready active stylus 30 for the measure
state after which the operation may repeat.
FIG. 4 illustrates an example method 400 of communication between
an active stylus 30 and a touch sensor 10. The method may start at
step 402, where a drive signal 70, such as a synchronization pulse,
is transmitted by the touch-sensor controller 12 on the horizontal
lines X.sub.0 . . . X.sub.N and vertical lines Y.sub.0 . . .
Y.sub.N. During this step, the horizontal lines X.sub.0 . . .
X.sub.N and vertical lines Y.sub.0 . . . Y.sub.N may be in a line
active state. After transmitting the drive signal 70, such as a
synchronization pulse, the method proceeds to step 404, where
touch-sensor controller 12 transitions the horizontal lines X.sub.0
. . . X.sub.N and vertical lines Y.sub.0 . . . Y.sub.N to a measure
lines state.
Meanwhile, active stylus 30 may be in a measure state. At step 502,
active stylus detects the drive signal 70 transmitted by
touch-sensor controller 12 at step 402 by sensing the drive signal
70 on stylus tip 34. In response to sensing the drive signal 70,
active stylus 30 proceeds to step 504 and transitions to the active
output state. While in the active output state 504, the active
stylus will then at step 506 output a high voltage on stylus tip
34.
At step 406, the high voltage output on stylus tip 34 results in a
charge being transferred to electrodes of touch-sensor controller
12 in proximity to active stylus tip 34 while they are in a measure
lines state. After a time sufficient to transfer the effective
charge as a result of the high output voltage on the stylus tip 34,
touch-sensor controller 12 may, at step 408, acquire measured
charge of horizontal lines X.sub.0 . . . X.sub.N and vertical lines
Y.sub.0 . . . Y.sub.N lines. At step 410 touch-sensor controller 12
may determine and/or track a location of active stylus 30. For
example, touch-sensor controller 12 may determine the location
according to any of the techniques discussed above. At step 412,
touch-sensor controller 12 may end the measured line state.
Meanwhile, active stylus 30 may end the high voltage output and end
the active output state.
After step 412 and step 508 complete, the touch-sensor controller
12 may transition back to an active line state at step 402 in which
the drive signal 70 may be transmitted, while active stylus 30
transitions back to a measure state at step 502. Thus, the method
of FIG. 4 may repeat, in particular embodiments.
Moreover, although this disclosure describes and illustrates
particular steps of the method of FIG. 4 as occurring in a
particular order, this disclosure contemplates any suitable steps
of the method of FIG. 4 occurring in any suitable order.
Furthermore, although this disclosure describes and illustrates
particular components, devices, or systems carrying out particular
steps of the method of FIG. 4, this disclosure contemplates any
suitable combination of any suitable components, devices, or
systems carrying out any suitable steps of the method of FIG.
4.
FIG. 5 illustrates an example timing diagram for communicating
between active stylus 30 and touch sensor 10. FIG. 5 illustrates an
example of a manner by which controller 12 may be synchronized with
the corresponding active stylus 30 timing.
At time 1, a synchronization pulse of width T0 is transmitted on
the drive lines of the touch sensor 10, which may be horizontal
lines X.sub.0 . . . X.sub.N and vertical lines Y.sub.0 . . .
Y.sub.N lines.
At time 2, the rising edge of the synchronization pulse stylus is
detected by active stylus 30.
At time 3, the synchronization pulse ends.
At time 4, active stylus 30 detects the falling edge of the
synchronization pulse.
At time 5, after the synchronization pulse is transmitted,
touch-sensor controller 12 transitions the active output state to a
measure state.
At time 6, active stylus 30 transitions to an active output
state.
At time 7, while in the active output state, active stylus 30
begins transmitting an active high output voltage on the active
stylus tip 34. The active high voltage may be of length T5. This
voltage causes a charge transfer to occur on the electrodes of the
touch sensor 10, indicated by the shaded vertical bar in the timing
diagram. Touch-sensor controller 12 waits an appropriate amount of
time (T4) for the charge transfer to occur before acquiring the
charge on horizontal lines X.sub.0 . . . X.sub.N and vertical lines
Y.sub.0 . . . Y.sub.N lines.
At time 8, touch-sensor controller 12 acquires the signals on the
horizontal lines X.sub.0 . . . X.sub.N and vertical lines Y.sub.0 .
. . Y.sub.N lines. The acquisition may require a time T6 to
complete.
At time 9, the acquisition is completed and the touch-screen
controller may determine a location of active stylus 30 based on
the acquired signals.
At time 10, touch-sensor controller 12 will transition back to a
line active, or pulse state.
At time 11, active stylus 30 ceases to output high voltage on
stylus tip 34.
At time 12, active stylus 30 transitions to a measure state.
After the timing sequence completes, the sequence repeats starting
at time 1.
Moreover, although this disclosure describes and illustrates
particular timing functions of FIG. 5 and illustrates the
communications between active stylus and touch screen device as
occurring in a particular order, this disclosure contemplates any
suitable steps of the method of FIG. 5 occurring in any suitable
order according to any suitable timing scenario. Furthermore,
although this disclosure describes and illustrates particular
components, devices, or systems carrying out the timing functions
of FIG. 5, this disclosure contemplates any suitable combination of
any suitable components, devices, or systems carrying out any
suitable steps of the method of FIG. 5.
Herein, reference to a computer-readable non-transitory storage
medium or media may include one or more semiconductor-based or
other integrated circuits (ICs) (such, as for example, a
field-programmable gate array (FPGA) or an application-specific IC
(ASIC)), hard disk drives (HDDs), hybrid hard drives (HHDs),
optical discs, optical disc drives (ODDs), magneto-optical discs,
magneto-optical drives, floppy diskettes, floppy disk drives
(FDDs), magnetic tapes, solid-state drives (SSDs), RAM-drives,
SECURE DIGITAL cards, SECURE DIGITAL drives, any other suitable
computer-readable non-transitory storage medium or media, or any
suitable combination of two or more of these, in particular
embodiments. A computer-readable non-transitory storage medium or
media may be volatile, non-volatile, or a combination of volatile
and non-volatile, in particular embodiments.
Herein, "or" is inclusive and not exclusive, unless expressly
indicated otherwise or indicated otherwise by context. Therefore,
herein, "A or B" means "A, B, or both," unless expressly indicated
otherwise or indicated otherwise by context. Moreover, "and" is
both joint and several, unless expressly indicated otherwise or
indicated otherwise by context. Therefore, herein, "A and B" means
"A and B, jointly or severally," unless expressly indicated
otherwise or indicated otherwise by context.
This disclosure encompasses all changes, substitutions, variations,
alterations, and modifications to the example embodiments herein
that a person having ordinary skill in the art would comprehend.
For example, in some embodiments, substantially all horizontal
lines X.sub.0 . . . X.sub.N and vertical lines Y.sub.0 . . .
Y.sub.N lines may be pulsed with drive signal 70. In other
embodiments, it may be desirable to acquire to transmit drive
signal 70 only on certain subsets of the horizontal and vertical
lines. Moreover, touch-sensor controller 12 may be configured to
sense the charge on substantially all horizontal and vertical lines
and/or sense the charge on groups of horizontal and vertical
lines.
According to the teachings of the present disclosure, active stylus
30 may detect both positive and negative edge of touch-sensor
controller 12 synchronization pulses. Active stylus 30 may generate
high voltage pulses on both the positive and negative edges. Such
an approach may allow touch-sensor controller 12 to suppress low
frequency noises and/or may be used to transfer data between active
stylus 30 and touch-sensor controller 12. As another example,
because active stylus 30 may receive drive signals 70 from
substantially all horizontal lines X.sub.0 . . . X.sub.N and
substantially all vertical lines Y.sub.0 . . . Y.sub.N lines, power
consumption may be reduced as a result of a reduced need to amplify
the signal received on active stylus tip 34 during the measure
state. This may also result in reduced production and/or
manufacturing costs. As another example, because of the pulsing of
substantially all horizontal lines X.sub.0 . . . X.sub.N and
substantially all vertical lines Y.sub.0 . . . Y.sub.N lines,
active stylus 30 may be capable of detecting the drive signal 70
even at some distance from touch screen sensor 10. In such
embodiments, active stylus 30 may be capable of communicating with
touch-sensor controller 12 even while active stylus 30 is hovering
above a surface of the touch screen and/or not in direct contact
with the touch screen. As another example, linearity may be
improved over active stylus solutions and/or a faster data exchange
rate may be achieved.
Moreover, although this disclosure describes and illustrates
respective embodiments herein as including particular components,
elements, functions, operations, or steps, any of these embodiments
may include any combination or permutation of any of the
components, elements, functions, operations, or steps described or
illustrated anywhere herein that a person having ordinary skill in
the art would comprehend. Furthermore, reference in the appended
claims to an apparatus or system or a component of an apparatus or
system being adapted to, arranged to, capable of, configured to,
enabled to, operable to, or operative to perform a particular
function encompasses that apparatus, system, component, whether or
not it or that particular function is activated, turned on, or
unlocked, as long as that apparatus, system, or component is so
adapted, arranged, capable, configured, enabled, operable, or
operative.
* * * * *