U.S. patent application number 16/655917 was filed with the patent office on 2020-02-13 for stylus pen.
The applicant listed for this patent is Sang-Hyun HAN, Leading UI Co., Ltd.. Invention is credited to Sang-Hyun HAN, Han-Hee HONG.
Application Number | 20200050315 16/655917 |
Document ID | / |
Family ID | 64097701 |
Filed Date | 2020-02-13 |
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United States Patent
Application |
20200050315 |
Kind Code |
A1 |
HAN; Sang-Hyun ; et
al. |
February 13, 2020 |
STYLUS PEN
Abstract
A touch system includes a touch panel, a stylus pen and a touch
sensing controller. The touch panel includes a plurality of driving
electrodes and a plurality of sensing electrodes. The stylus pen
provides the touch panel with a pen frequency signal set for
detecting a position of a stylus pen and a pressure of the stylus
pen. The touch sensing controller outputs a plurality of driving
signals having different frequency components to the touch panel
and determines at least one of touch coordinates of a finger and
touch coordinates of the stylus pen based on a plurality of sensing
signals received from the touch panel.
Inventors: |
HAN; Sang-Hyun;
(Gyeonggi-do, KR) ; HONG; Han-Hee; (Gyeonggi-do,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HAN; Sang-Hyun
Leading UI Co., Ltd. |
Gyeonggi-do
Gyeonggi-do |
|
KR
KR |
|
|
Family ID: |
64097701 |
Appl. No.: |
16/655917 |
Filed: |
October 17, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15595140 |
May 15, 2017 |
10466834 |
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16655917 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 3/0442 20190501;
G06F 3/03545 20130101; G06F 3/04162 20190501; G06F 3/0441 20190501;
G06F 3/0446 20190501; G06F 3/0416 20130101; G06F 3/04166 20190501;
G06F 3/044 20130101; G06F 2203/04104 20130101 |
International
Class: |
G06F 3/041 20060101
G06F003/041; G06F 3/0354 20060101 G06F003/0354; G06F 3/044 20060101
G06F003/044 |
Claims
1. A stylus pen comprising: a conductive tip contactable with a
touch panel; a pressure sensor measuring a pressure of the
conductive tip applied to the touch panel and outputting a pen
pressure signal; a frequency signal generator generating a pressure
sensing signal based on the pen pressure signal and generating a
position sensing signal for sensing a position of the stylus pen;
and a mixer mixing the position sensing signal and the pressure
sensing signal to provide a mixing signal to the conductive
tip.
2. The stylus pen of claim 1, wherein the pressure sensing signal
has a uniform frequency and varied amplitude in accordance with the
pen pressure signal.
3. The stylus pen of claim 1, wherein frequencies of each of the
pressure sensing signal and the position sensing signal are
different from a frequency of a driving signal applied to a driving
electrode of the touch panel.
Description
RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. patent
application Ser. No. 15/595,140, filed on May 15, 2017. The
disclosure of the above listed application is hereby incorporated
by reference herein in its entirety.
BACKGROUND OF THE INVENTION
Technical Field
[0002] Exemplary embodiments of the present invention relate to a
touch system and a touch sensing controller and a stylus pen
employed in the touch system. More particularly, the present
invention relates to a touch system capable of simultaneously
realizing finger touch recognition and pen touch recognition and
capable of realizing multitouch recognition of stylus pens, and a
touch sensing controller and a stylus pen employed in the touch
system.
Discussion of the Related Art
[0003] The use of touch screen interfaces and styluses has been
widely established. Touch screen designs have incorporated many
different technologies including resistive, capacitive, inductive,
and radio frequency sensing arrays. For example, resistive touch
screens are passive devices well suited for use with a passive
stylus.
[0004] Although resistive touch screens can sense the input from
nearly any object, multi-touch is generally not supported. An
example of a multi-touch application may be applying two or more
fingers to the touch screen. Another example may be inputting a
signature, which may include simultaneous palm and stylus input
signals. Due to these and other numerous disadvantages, capacitive
touch screens are increasingly replacing resistive touch screens in
the consumer marketplace.
[0005] Various tethered active stylus approaches have been
implemented for use with touch screens and are found in many
consumer applications such as point-of-sale terminals (e.g., the
signature pad used for credit card transactions in retail stores)
and other public uses. However, the need for a tethered cable is a
significant drawback for private applications such as personal
computers ("PCs"), smart phones, and tablet PCs.
SUMMARY
[0006] Exemplary embodiments of the present invention provide a
touch system capable of simultaneously realizing finger touch
recognition and pen touch recognition, and realizing multi-touch
recognition of stylus pens.
[0007] Exemplary embodiments of the present invention also provide
a touch sensing controller employed in the above-mentioned touch
system.
[0008] Exemplary embodiments of the present invention further also
provide a stylus pen employed in the above-mentioned touch
system.
[0009] According to one aspect of the present invention, a touch
system includes a touch panel, a stylus pen and a touch sensing
controller. The touch panel includes a plurality of driving
electrodes and a plurality of sensing electrodes. The stylus pen
provides the touch panel with a pen frequency signal set for
detecting a position of a stylus pen and a pressure of the stylus
pen. The touch sensing controller outputs a plurality of driving
signals having different frequency components to the touch panel
and determines at least one of touch coordinates of a finger and
touch coordinates of the stylus pen based on a plurality of sensing
signals received from the touch panel.
[0010] In an exemplary embodiment, the pen frequency signal may be
a mixture of a position sensing signal set for sensing a position
of the stylus pen and a pressure sensing signal set for sensing a
pressure of the stylus pen.
[0011] In an exemplary embodiment, the position sensing signal and
the driving signal may have different frequency components.
[0012] In an exemplary embodiment, the pressure sensing signal and
the driving signal may have different frequency components.
[0013] In an exemplary embodiment, the touch sensing controller may
includes a touch driving unit, a touch sensing unit and a touch
determining unit. The touch driving unit is connected to the
driving electrodes to output the driving signals to the driving
electrodes. The touch sensing unit is connected to the sensing
electrodes to receive the sensing signals through the sensing
electrodes. The touch determining unit determines touch coordinates
based on the sensing signals received through the touch sensing
unit.
[0014] In an exemplary embodiment, the touch driving unit may
include a transmission signal generating part and a transmission
multiplexing part. The transmission signal generating part includes
a plurality of transmission signal generators generating different
driving signals. The transmission multiplexing part includes a
plurality of transmission multiplexers having a first transmission
input terminal connected to the transmission signal generator, a
second transmission input terminal connected to the touch sensing
unit, and an output terminal connected to the driving electrode.
The first transmission input terminal is connected to the
transmission output terminal or the second transmission input
terminal is connected to the output terminal in response to a
multiplexer control signal provided from an external device.
[0015] In an exemplary embodiment, the touch sensing unit may
includes a reception multiplexing part, a reception sensing part,
an analog-to-digital converting part and a fast Fourier transform
part. The reception multiplexing part includes a plurality of
reception multiplexers having a reception output terminal, a first
reception input terminal connected to the sensing electrode and a
second reception input terminal connected to a second transmission
input terminal of a transmission multiplexing part of the touch
driving unit. The first reception input terminal is connected to
the reception output terminal or the second reception input
terminal is connected to the reception output terminal in response
to the multiplexer control signal. The reception sensing part
includes a plurality of reception sensors connected to a reception
output terminal of the reception multiplexers. The
analog-to-digital converting part digitally converts sensing
signals received through the reception sensors. The fast Fourier
transform part Fourier-transforms the sensing signal digitally
converted by the analog-to-digital conversion part.
[0016] In an exemplary embodiment, in response to the multiplexer
control signal, first input terminals of the transmission
multiplexers and the driving electrodes are connected to each
other, and first input terminals of the reception multiplexers and
the receive sensing part are connected to each other, so that touch
coordinates of the finger, a first axis coordinates of the stylus
pen and a pen pressure information of the stylus pen are
sensed.
[0017] In an exemplary embodiment, in response to the multiplexer
control signal, second input terminals of the transmission
multiplexers and the driving electrodes are connected to each
other, and second input terminals of the reception multiplexers and
the receive sensing part are connected to each other, so that a
second axis coordinate of the stylus pen and a pen pressure
information of the stylus pen are sensed.
[0018] In an exemplary embodiment, the driving signal may be
simultaneously output to the touch panel.
[0019] According to another aspect of the present invention, a
touch sensing controller includes a touch driving unit, a touch
sensing unit and a touch determining unit. The touch driving unit
is connected to driving electrodes of a touch panel contacting with
a stylus pen that outputs a pen frequency signal set to detect a
position of the stylus pen and a pressure of the stylus pen. The
touch driving unit outputs the driving signals to the driving
electrodes. The touch sensing unit is connected to sensing
electrodes of the touch panel to receive the sensing signals
through the sensing electrodes. The touch determining unit
determines at least one of touch coordinates of a finger and touch
coordinates of the stylus pen based on the sensing signals.
[0020] In an exemplary embodiment, the touch driving unit may
include a transmission signal generating part and a transmission
multiplexing part. The transmission signal generating part includes
a plurality of transmission signal generators that generates
driving signals having different frequency components. The
transmission multiplexing part includes a plurality of transmission
multiplexers having a first transmission input terminal connected
to the transmission signal generator, a second transmission input
terminal connected to the touch sensing unit, and a transmission
output terminal connected to the driving electrode. The first
transmission input terminal and the transmission output terminal
are connected to each other or the second transmission input
terminal and the transmission output terminal are connected to each
other, in response to a multiplexer control signal provided from an
external device.
[0021] In an exemplary embodiment, the touch sensing unit may
includes a reception multiplexing part, a reception sensing part,
an analog-to-digital converting part and a fast Fourier transform
part. The reception multiplexing part includes a plurality of
reception multiplexers having a reception output terminal, a first
reception input terminal connected to the sensing electrode and a
second reception input terminal connected to a second transmission
input terminal of the transmission multiplexing part of the touch
driving unit. The first reception input terminal and the reception
output terminal are connected to each other or the second reception
input terminal and the receiving output terminal are connected to
each other, in response to the multiplexer control signal. The
reception sensing part includes a plurality of reception sensors
connected to a reception output terminal of the reception
multiplexers. The analog-to-digital converting part digitally
converts the sensing signals received through the reception
sensors. The fast Fourier transform part Fourier-transforms the
sensing signal digitally converted by the analog-to-digital
converting part.
[0022] In an exemplary embodiment, in response to the multiplexer
control signal, first input terminals of the transmission
multiplexers and the driving electrodes may be connected to each
other, and first input terminals of the reception multiplexers and
the receive sensing part may be connected to each other, so that a
touch coordinate of the finger, a first axis coordinate of the
stylus pen, and a pressure information of the stylus pen are
sensed.
[0023] In an exemplary embodiment, in response to the multiplexer
control signal, second input terminals of the transmission
multiplexers and the driving electrodes may be connected to each
other, and second input terminals of the reception multiplexers and
the receive sensing part may be connected to each other, so that a
second axis coordinate of the stylus pen and a pressure information
of the stylus pen are sensed.
[0024] According to another aspect of the present invention, a
stylus pen includes a conductive tip, a pressure sensor, a
frequency signal generator and a mixer. The conductive tip is
contactable with a touch panel. The pressure sensor measures a
pressure of the conductive tip applied to the touch panel and
outputting a pen pressure signal. The frequency signal generator
generates a pressure sensing signal based on the pen pressure
signal and generates a position sensing signal for sensing a
position of the stylus pen. The mixer mixes the position sensing
signal and the pressure sensing signal to provide a mixing signal
to the conductive tip.
[0025] In an exemplary embodiment, the pressure sensing signal may
have a uniform frequency and varied amplitude in accordance with
the pen pressure signal.
[0026] In an exemplary embodiment, frequencies of each of the
pressure sensing signal and the position sensing signal may be
different from a frequency of a driving signal applied to a driving
electrode of the touch panel.
[0027] According to a touch system and a touch sensing controller
and a stylus pen employed therein, the driving signals having
different frequency components are output to the touch panel and at
least one of the touch coordinates of the finger and the touch
coordinates of the stylus pen is determinated based on the sensing
signals received at the touch panel, so that the touch recognition
may be realized at the same time. Further, in order to sense a
position of the stylus pen and a pressure of the stylus pen, the
stylus pen is designed to set a frequency of a pen frequency signal
different from a frequency of a driving signal applied to the touch
panel, so that plural stylus pens may be used in one touch
panel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The above and other features and aspects of the present
invention will become more apparent by describing in detailed
exemplary embodiments thereof with reference to the accompanying
drawings, in which:
[0029] FIG. 1 is a schematic diagram illustrating a touch system
according to an exemplary embodiment of the present invention;
[0030] FIG. 2 is a configuration diagram illustrating a touch
coordinate determination by a touch sensing device shown in FIG.
1:
[0031] FIG. 3A is a schematic diagram illustrating an appearance of
the stylus pen shown in FIG. 1, and FIG. 3B is a configuration
diagram schematically illustrating the stylus pen shown in FIG.
1;
[0032] FIG. 4 is a block diagram illustrating the stylus pen shown
in FIG. 1;
[0033] FIG. 5 is waveform diagrams illustrating an example of a
position sensing signal and a pressure sensing signal output from
the stylus pen shown in FIG. 1;
[0034] FIG. 6 is a circuit diagram illustrating an example of the
stylus pen shown in FIG. 1;
[0035] FIG. 7 is a circuit diagram illustrating another example of
the stylus pen shown in FIG. 1;
[0036] FIG. 8A is a schematic diagram of a touch panel illustrating
a touch by a finger, and FIG. 8B is a waveform diagram illustrating
a touch coordinate recognition through a frequency spectrum
analysis of a sensing signal by a finger touch;
[0037] FIG. 9A is a schematic diagram of a touch panel illustrating
a touch by a stylus pen, and
[0038] FIG. 9B is a waveform diagram illustrating touch coordinate
recognition through frequency spectrum analysis of a sensing signal
by a stylus pen:
[0039] FIG. 10A is a schematic diagram of a touch panel
illustrating a touch by a finger and a stylus pen, and FIG. 10B is
a waveform diagram illustrating touch coordinate recognition
through a frequency spectrum analysis of a sensing signal by a
finger and a stylus pen;
[0040] FIG. 11A and FIG. 11B are configuration diagrams of a touch
sensing device illustrating a touch coordinates recognition of a
finger and a stylus pen;
[0041] FIG. 12 is a flowchart illustrating a touch coordinate
recognition method in which the finger and the stylus pen are
individually recognized in the touch sensing device shown in FIG.
11A and FIG. 11B; and
[0042] FIG. 13 is a flowchart illustrating a touch coordinate
recognition method in which the finger and the stylus pen are
simultaneously recognized in the touch sensing device shown in FIG.
11A and FIG. 11B.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The present invention is described more fully hereinafter
with reference to the accompanying drawings, in which exemplary
embodiments of the present invention are shown. The present
invention may, however, be embodied in many different forms and
should not be construed as limited to the exemplary embodiments set
forth herein. Rather, these exemplary embodiments are provided so
that this disclosure will be thorough and complete, and will fully
convey the scope of the present invention to those skilled in the
art. In the drawings, the sizes and relative sizes of layers and
regions may be exaggerated for clarity.
[0044] It will be understood that when an element or layer is
referred to as being "on," "connected to" or "coupled to" another
element or layer, it can be directly on, connected or coupled to
the other element or layer or intervening elements or layers may be
present. In contrast, when an element is referred to as being
"directly on." "directly connected to" or "directly coupled to"
another element or layer, there are no intervening elements or
layers present. Like numerals refer to like elements throughout. As
used herein, the term "and/or" includes any and all combinations of
one or more of the associated listed items.
[0045] It will be understood that, although the terms first,
second, third etc. may be used herein to describe various elements,
components, regions, layers and/or sections, these elements,
components, regions, layers and/or sections should not be limited
by these terms. These terms are only used to distinguish one
element, component, region, layer or section from another region,
layer or section. Thus, a first element, component, region, layer
or section discussed below could be termed a second element,
component, region, layer or section without departing from the
teachings of the present invention.
[0046] Spatially relative terms, such as "beneath," "below,"
"lower," "above," "upper" and the like, may be used herein for ease
of description to describe one element or feature's relationship to
another element(s) or feature(s) as illustrated in the figures. It
will be understood that the spatially relative terms are intended
to encompass different orientations of the device in use or
operation in addition to the orientation depicted in the figures.
For example, if the device in the figures is turned over, elements
described as "below" or "beneath" other elements or features would
then be oriented "above" the other elements or features. Thus, the
exemplary term "below" can encompass both an orientation of above
and below. The device may be otherwise oriented (rotated 90 degrees
or at other orientations) and the spatially relative descriptors
used herein interpreted accordingly.
[0047] The terminology used herein is for the purpose of describing
particular exemplary embodiments only and is not intended to be
limiting of the present invention. As used herein, the singular
forms "a," "an" and "the" are intended to include the plural forms
as well, unless the context clearly indicates otherwise. It will be
further understood that the terms "comprises" and/or "comprising,"
when used in this specification, specify the presence of stated
features, integers, steps, operations, elements, and/or components,
but do not preclude the presence or addition of one or more other
features, integers, steps, operations, elements, components, and/or
groups thereof.
[0048] Exemplary embodiments of the invention are described herein
with reference to cross-sectional illustrations that are schematic
illustrations of idealized exemplary embodiments (and intermediate
structures) of the present invention. As such, variations from the
shapes of the illustrations as a result, for example, of
manufacturing techniques and/or tolerances, are to be expected.
Thus, exemplary embodiments of the present invention should not be
construed as limited to the particular shapes of regions
illustrated herein but are to include deviations in shapes that
result, for example, from manufacturing. For example, an implanted
region illustrated as a rectangle will, typically, have rounded or
curved features and/or a gradient of implant concentration at its
edges rather than a binary change from implanted to non-implanted
region. Likewise, a buried region formed by implantation may result
in some implantation in the region between the buried region and
the surface through which the implantation takes place. Thus, the
regions illustrated in the figures are schematic in nature and
their shapes are not intended to illustrate the actual shape of a
region of a device and are not intended to limit the scope of the
present invention.
[0049] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
[0050] Hereinafter, the present invention will be explained in
detail with reference to the accompanying drawings.
[0051] FIG. 1 is a schematic diagram illustrating a touch system
according to an exemplary embodiment of the present invention. In
particular, it is a schematic diagram illustrating the simultaneous
use of a stylus pen and a finger on a touch panel.
[0052] Referring to FIG. 1, a touch system includes a touch sensing
device 100 and a stylus pen 200 to recognize a touch operation of a
finger 300 by the user or a touch operation of the stylus pen 200.
The touch sensing device 100 detects a position of the finger 300
of the user to determine a touch coordinates of the finger 300 or
detects a position of the stylus pen 200 to determine a touch
coordinates of the stylus pen 200. A touch coordinates of the
finger 300 and a touch coordinates of the stylus pen 200 may be
detected at the same time.
[0053] FIG. 2 is a configuration diagram illustrating a touch
coordinate determination by a touch sensing device shown in FIG.
1.
[0054] Referring to FIG. 1 and FIG. 2, a plurality of driving
signals is applied to different driving electrodes provided on a
touch panel. Each of the driving signals has different frequency
components. Hereinafter, for convenience of explanation, it is
described that a first driving signal STX0, a second driving signal
STX1, a third driving signal STX2 and a fourth driving signal STX3
are applied to the touch panel. Therefore, the first driving signal
STX0 has a first frequency component f0, the second driving signal
STX1 has a second frequency component f1, and the third driving
signal STX2 has a third frequency component f2, and the fourth
driving signal STX3 has a fourth frequency component f3. Each of
the first to fourth frequency components f0, f1, f2 and f3 is
different from each other.
[0055] A sensing electrode RX of the touch panel receives sensing
signal SRX sensed corresponding to the first to fourth driving
signals STX0, STX1, STX2 and STX3. The sensing signal is mixed by
the touch panel; however an amplitude of the sensing signal SRX is
decreased in comparison to the driving signals STX0, STX1. STX2 and
STX3.
[0056] The sensing signal SRX is amplified by an amplifier and then
supplied to a fast Fourier transform (FFT) processing block. The
FFT processed sensing signals are disassembled and interpreted to
derive coordinates of where the touch occurred. The amplifier or
the FFT processing block may be provided in a touch sensing
controller provided in the touch sensing device 100.
[0057] FIG. 3A is a schematic diagram illustrating an appearance of
the stylus pen shown in FIG. 1, and FIG. 3B is a configuration
diagram schematically illustrating the stylus pen shown in FIG.
1.
[0058] FIG. 3A and FIG. 3B, a stylus pen 200 includes a
pencil-shaped conductive case 202, a conductive tip 204 connected
to one side of the conductive case 202, a pen pressure sensor 206
disposed between the conductive case 202 and the conductive tip
204, a frequency signal generator 208 and a mixer 210.
[0059] The conductive tip 204 has a shape that can be brought into
contact with the touch panel.
[0060] The pen pressure sensor 206 measures a pressure of the
conductive tip 204 applied to the touch panel and outputs a
pressure signal. That is, the pen pressure sensor 206 generates an
electric signal in accordance with a pressure applied to the
conductive tip 204 protruding from an end portion of a stylus pen
body. For example, the pen pressure sensor 206 generates an
electrical signal in accordance with a pressure applied to the
conductive tip 204 by a user's writing operation. The conductive
tip 204 may be connected to the pen pressure sensor 206 to transmit
a pressure generated by the conductive tip 204 to the pen pressure
sensor 206.
[0061] The frequency signal generator 208 generates a position
sensing signal SPO that is set to detect a position of a stylus pen
200 and generates a pressure sensing signal SPR that is set to
measure a pressure of a stylus pen based on the pressure signal.
Hereinafter, for convenience of description, an example in which
four driving electrodes and four sensing electrodes are disposed in
the touch panel will be described. In this case, a first driving
signal STX0, a second driving signal STX1, a third driving signal
STX2 and a fourth driving signal STX3 are applied to the driving
electrodes. Accordingly, the first driving signal STX0 has a first
frequency component f0, the second driving signal STX1 has a second
frequency component f1, the third driving signal STX2 has a third
frequency component f1, and the fourth driving signal STX3 has a
fourth frequency component f3. Each of the first to fourth
frequency components f0, f1, f2 and f3 is different from each
other. Moreover, a fifth frequency component f4 of the position
sensing signal SPO and a sixth frequency component f5 of the
pressure sensing signal SPR are different from the first to fourth
frequency components f0, f1, f2 and f3.
[0062] The mixer 210 mixes the position sensing signal SPO and the
pressure sensing signal SPR to output a mixing signal to the
conductive tip 204.
[0063] As described above, in order to sense a position of the
stylus pen and a pressure of the stylus pen, the stylus pen is
designed to set a frequency of a pen frequency signal different
from a frequency of a driving signal applied to the touch panel, so
that plural stylus pens may be used in one touch panel.
[0064] FIG. 4 is a block diagram illustrating the stylus pen 200
shown in FIG. 1.
[0065] Referring to FIG. 4, the stylus pen 200 includes buttons
250, a button processing unit 252, a pen control unit 260, a pen
pressure sensor 206, a pen pressure processing unit 207, a pen
control unit 260, a power managing unit 270, a battery 272, a
waveform generating unit 280 and a waveform driving unit 290.
[0066] The buttons 250 are varied according to a user's operation
to provide a button signal to the button processing unit 252. The
buttons 250 may be mechanical buttons or electrostatic buttons. The
buttons 250 may provide additional functionality including "left
click" and "right click" functions similar to those of a computer
mouse but not limited thereto. The buttons 250 of the stylus pen
200 may be coupled to a pen control unit (CPU) 260. The buttons 250
may be mechanical, electrical, capacitive, or other types known to
those skilled in the art.
[0067] The button processing unit 252 converts a button signal
provided from the buttons 250 into a digital signal and provides
the digital signal to the pen control unit 260.
[0068] The pen pressure sensor 206 senses a pressure applied to the
touch panel by the stylus pen 200 and provides a sensed pressure
signal to the pen pressure processing unit 207.
[0069] The pen pressure processing unit 207 provides a pressure
signal provided from the pen pressure sensor 206 to the waveform
driving unit 280.
[0070] The pen control unit 260 may control an operation of
components provided in the stylus pen 200.
[0071] The power managing unit 270 supplies the power of the
battery 272 to the respective components. The power supply is
boosted as needed, and the boosted power supply is supplied to the
respective components. Conventionally, a stylus pen may be
classified into an active type and a passive type according to the
presence or absence of a battery. According to the present
invention, since the battery 272 is provided in the stylus pen 200,
the stylus pen according to the present invention is an active
stylus pen.
[0072] The waveform generating unit 280 provides the waveform
driving unit 290 with a first waveform for generating a position
sensing signal SPO or a second waveform for generating a pressure
sensing signal SPR in response to a control of the pen control unit
260. The first waveform or the second waveform may be a sinusoidal
wave.
[0073] The waveform driving unit 290 amplifies the first waveform
or the second waveform generated by the waveform generating unit
280, mixes the amplified waveforms, and outputs the mixed signal.
In the present exemplary embodiment, a pen pressure processing unit
207, a waveform generating unit 280 and a waveform driving unit 290
may define the frequency signal generator 208 shown in FIG. 3.
[0074] FIG. 5 is waveform diagrams illustrating an example of a
position sensing signal SPO and a pressure sensing signal SPR
output from the stylus pen shown in FIG. 1.
[0075] Referring to FIG. 5, a fifth frequency component f4 of a
position sensing signal SPO is set differently from the first to
fourth frequency components f0, f1, f2 and f3 of the driving signal
provided to the driving electrodes of the touch panel. Moreover, a
sixth frequency component f5 of the pressure sensing signal SPR is
set differently from the first to fourth frequency components f0,
f1, f2 and f3 of the driving signal provided to the driving
electrodes of the touch panel. Moreover, a fifth frequency
component f4 of the position sensing signal SPO and a sixth
frequency component f5 of the pressure detection signal SPR are set
differently from each other.
[0076] The position sensing signal SPO has a fixed frequency and a
fixed amplitude.
[0077] The pressure sensing signal SPR has a fixed frequency and a
variable amplitude. An amplitude of the pressure sensing signal SPR
may vary according to a pen pressure signal corresponding to a
pressure applied to a stylus pen. For example, a pressure sense
signal SPR having the maximum amplitude may be outputted when a
high pen pressure signal is detected, and a pressure sense signal
SPR having the minimum amplitude may be outputted when a low pen
pressure signal is detected.
[0078] Meanwhile, the amplitude of the pressure sensing signal SPR
may vary according to a button that can be operated by a user. The
button may be provided in a stylus pen, and the amplitude of the
pressure sensing signal SPR may be varied in accordance to the
button.
[0079] FIG. 6 is a circuit diagram illustrating an example of the
stylus pen shown in FIG. 1.
[0080] Referring to FIG. 6, a waveform generating unit 280 includes
a fifth frequency signal generator 282 and a sixth frequency signal
generator 284, and a waveform driving unit 290 includes a first
amplifying unit 292, a second amplifying unit 294, a mixer 210 and
a conductive tip 204.
[0081] The first amplifying unit 292 includes a first resistor R1,
a second resistor R2 and a first operational amplifier OP1. A first
terminal of the first resistor R1 receives a position sensing
signal SPO and a second terminal of the first resistor R1 is
connected to an inverting terminal of the first operational
amplifier OP1. A first terminal of the second resistor R2 is
connected to the second terminal of the first resistor R1 and the
inverting terminal of the first operational amplifier OP1, and a
second terminal of the second resistor R2 is connected to the mixer
210.
[0082] The second resistor R2 may be a variable resistor. The
inverting terminal of the first operational amplifier OP1 is
connected to the second terminal of the first resistor R1 and the
first terminal of the second resistor R2, and a non-inverting
terminal of the first operational amplifier OP1 is connected to a
reference voltage Vref.
[0083] The second amplifying unit 294 includes a third resistor R3,
a fourth resistor R4 and a second operational amplifier OP2. A
first terminal of the third resistor R3 receives a position sensing
signal SPO and the second terminal of the third resistor R3 is
connected to an inverting terminal of the second operational
amplifier OP2. A first terminal of the fourth resistor R4 is
connected to the second terminal of the third resistor R3 and the
inverting terminal of the second operational amplifier OP2, and a
second terminal of the fourth resistor R4 is connected to the mixer
210. The fourth resistor R4 may be a variable resistor. An
inverting terminal of the second operational amplifier OP2 is
connected to a second terminal of the third resistor R3 and a first
terminal of the fourth resistor R4, and a non-inverting terminal of
the second operational amplifier OP2 is connected to the reference
voltage Vref.
[0084] The mixer 210 includes a fifth resistor R5, a sixth resistor
R6, a third operational amplifier OP3 and a seventh resistor R7. A
first terminal of the fifth resistor R5 is connected to an output
terminal of a first amplifying unit, and a second terminal of the
fifth resistor R5 is connected to an inverting terminal of the
third operational amplifier OP3. A first terminal of the sixth
resistor R6 is connected to an output terminal of the second
amplifying unit, and a second terminal of the sixth resistor R6 is
connected to an inverting terminal of the third operational
amplifier OP3. The seventh resistor R7 is connected to an inverting
terminal and an output terminal of the third operational amplifier
OP3. An inverting terminal of the third operational amplifier OP3
is connected to the second terminal of the fifth resistor R5 and
the second terminal of the sixth resistor R6, and a non-inverting
terminal of the third operational amplifier OP3 is connected to the
reference voltage Vref.
[0085] In the foregoing specification, it has been described that
the position sensing signal SPO and the pressure sensing signal SPR
are generated separately, and the generated signals are amplified
and then mixed to provide a pen frequency signal to the conductive
tip.
[0086] FIG. 7 is a circuit diagram illustrating another example of
the stylus pen shown in FIG. 1;
[0087] Referring to FIG. 7, a waveform generating unit 280 may
include a digital function generator that provides a sinusoidal
wave to the waveform driver 290. The digital function generator may
include a plurality of direct digital synthesis (hereinafter,
"DDS") modules configured to precisely generate a sinusoidal wave
of a precise frequency, period, and phase in response to control of
the pen control unit 260 (shown in FIG. 4).
[0088] Each of the DDS modules may generate a plurality of
frequency signals. For example, a position sensing signal SPO
having a fifth frequency component f4 and a pressure sensing signal
SPR having a sixth frequency component f5 may be generated.
Moreover, a signal having a frequency component fn-1, a signal
having a frequency component fn, or the like may be generated.
Here, the signal having the frequency component fn-1 may be a
frequency component corresponding to a first button provided to the
stylus pen, and the signal having the frequency component fn may
correspond to a second button provided to the stylus pen.
[0089] The waveform driving unit 290 includes a first resistor R1,
a second resistor R2 and a first operational amplifier OP1. A first
terminal of the first resistor R1 receives a sinusoidal signal from
the waveform generating unit 280, and a second terminal of the
first resistor R1 is connected to an inverting terminal of the
first operational amplifier OP1. A first terminal of the second
resistor R2 is connected to the second terminal of the first
resistor R1 and the inverting terminal of the first operational
amplifier OP1, and a second terminal of the second resistor R2 is
connected to the conductive tip 204. The second resistor R2 may be
a variable resistor. The inverting terminal of the first
operational amplifier OP1 is connected to the second terminal of
the first resistor R1 and a first terminal of the second resistor
R2, and a non-inverting terminal of the first operational amplifier
OP1 is connected to the reference voltage Vref.
[0090] FIG. 8A is a schematic diagram of a touch panel illustrating
a touch by a finger, and FIG. 8B is a waveform diagram illustrating
a touch coordinate recognition through a frequency spectrum
analysis of a sensing signal by a finger touch.
[0091] Referring to FIG. 8A, a first driving electrode TX0, a
second driving electrode TX1, a third driving electrode TX2 and a
fourth driving electrode TX3 are arranged in a horizontal direction
on a touch panel, and a first sensing electrode RX0, a second
sensing electrode RX1, a third sensing electrode RX2 and a fourth
sensing electrode RX3 are arranged in the longitudinal direction on
the touch panel. The first to fourth driving electrodes TX0, TX1,
TX2 and TX3 are arranged in a lower area of the touch panel and the
first to fourth sensing electrodes RX0, RX1, RX2 and RX3 are
arranged in an upper area of the touch panel.
[0092] A first driving signal STX0, a second driving signal STX0, a
third driving signal STX2 and a fourth driving signal STX3 are
applied to the first driving electrode TX0, the second driving
electrode TX1, the third driving electrode TX2 and the fourth
driving electrode TX3, respectively. First to fourth sensing
signals SRX0, SRX1, SRX2 and SRX3 corresponding to the applied
driving signals STX0, STX1, STX2 and STX3 are received through a
first sensing electrode RX0, a second sensing electrode RX1, a
third sensing electrode RX2 and a fourth sensing electrode RX3,
respectively. The received sensing signals are subjected to FFT
processing to determine touch coordinates.
[0093] Referring to FIG. 8B, a sensing signal received through a
second sensing electrode RX1 is subjected to FFT processing.
[0094] In the case of a base state in which there is no touch
operation, the FFT-processed sensing signal has a first frequency
component f0, a second frequency component f1, a third frequency
component f2 and a fourth frequency component 13. Here, the
amplitudes of the first to fourth frequency components f0, f1, f2
and f3 are equal to each other.
[0095] When a finger touches an area where the second driving
electrode TX1 intersects with the second sensing electrode RX1, the
FFT-processed sensing signal has a first frequency component f0, a
second frequency component f1, a third frequency component f2 and a
fourth frequency component f3. In this case, the amplitudes of the
first frequency component f0, the third frequency component f2 and
the fourth frequency component 13 are substantially equal to each
other. The amplitude of the second frequency component f1 is
smaller than the amplitude of the first frequency component f0.
[0096] When a waveform of a finger touch state is subtracted from a
waveform of a base state, the second frequency component f1 only
remains. The amplitude of the second frequency component f1
remaining after the subtraction may correspond to a finger touch
sensitivity.
[0097] Therefore, since the second frequency component f1 is
detected corresponding to the second sensing electrode RX1, the
second driving electrode TX1 delivering a second driving signal
STX1 having the second frequency component f1 and the second
sensing electrode RX1 are detected as touch coordinates of a
finger.
[0098] FIG. 9A is a schematic diagram of a touch panel illustrating
a touch by a stylus pen, and FIG. 9B is a waveform diagram
illustrating touch coordinate recognition through frequency
spectrum analysis of a sensing signal by a stylus pen.
[0099] Since the touch panel shown in FIG. 9A has been described
with reference to FIG. 8B, a description thereof will be
omitted.
[0100] Referring to FIG. 9B, a sensing signal received through a
second sensing electrode RX1 is FFT-processed.
[0101] In the case of a base state in which there is no touch
operation, the FFT-processed sensing signal has a first frequency
component f0, a second frequency component f1, a third frequency
component f2 and a fourth frequency component f3. Here, the
amplitudes of the first to fourth frequency components f0, f1, f2
and f3 are equal to each other.
[0102] When a stylus pen touches a region where the second driving
electrode TX1 intersect with the second sensing electrode RX, the
FFT-processed sensing signal has a first frequency component f0, a
second frequency component f1, a third frequency component f2, a
fourth frequency component f3, a fifth frequency component f5 and a
sixth frequency component f6. In this case, the amplitudes of the
first to fourth frequencies f, f1, f2 and f3 are substantially
equal to each other. The amplitude of the fifth frequency component
f5 is smaller than the amplitude of the first frequency component
f0. The amplitude of the sixth frequency component f6 is smaller
than the amplitude of the first frequency component f0. The
amplitude of the sixth frequency component f6 is smaller than the
amplitude of the fifth frequency component f5.
[0103] When a waveform of a stylus pen touch state is subtracted
from a waveform of the base state, the fifth frequency component f5
and the sixth frequency component f6 only remain. The amplitude of
the fifth frequency component f5 remaining after the subtraction
may correspond to a touch sensitivity of a stylus pen. Moreover,
the amplitude of the sixth frequency component f6 remaining after
the subtraction may correspond to a pen pressure sensitivity of the
stylus pen.
[0104] Thus, since the fifth frequency component f5 is detected
corresponding to the second sensing electrode RX1, it may be
confirmed that a stylus pen is disposed on the second sensing
electrode RX1. Therefore, the second sensing electrode RX1 is
detected as a first axis coordinate (e.g., X coordinate) of the
stylus pen.
[0105] The touch coordinates by the stylus pen may be recognized in
the above-described manner, and a more detailed description will be
described with reference to FIGS. 11A to 13 described later.
[0106] FIG. 10A is a schematic diagram of a touch panel
illustrating a touch by a finger and a stylus pen, and FIG. 10B is
a waveform diagram illustrating touch coordinate recognition
through a frequency spectrum analysis of a sensing signal by a
finger and a stylus pen.
[0107] Since the touch panel shown in FIG. 10A has been described
with reference to FIG. 8B, a description thereof will be
omitted.
[0108] Referring to FIG. 10B, a sensing signal received through a
second sensing electrode RX1 is FFT-processed.
[0109] In the case of a base state in which there is no touch
operation, the FFT-processed sensing signal has a first frequency
component f0, a second frequency component f1, a third frequency
component f2 and a fourth frequency component f3. Here, the
amplitudes of the first to fourth frequency components f0, f1, f2
and f3 are equal to each other.
[0110] When a finger touches an area where the second driving
electrode TX1 intersects with the second sensing electrode RX1 and
a stylus pen touches an area where the third driving electrode TX2
intersects with the second sensing electrode RX1, the FFT-processed
sensing signal has a first frequency component f0, a second
frequency component f1, a third frequency component f2, a fourth
frequency component f3, a fifth frequency component f5 and a sixth
frequency component f6. In this case, the amplitudes of the first
frequency component f0, the third frequency component f2 and the
fourth frequency component f3 are substantially equal to each
other. The amplitude of the second frequency component f1 is
smaller than the amplitude of the first frequency component f0. The
amplitude of the fifth frequency component f5 is smaller than the
amplitude of the first frequency component f0. The amplitude of the
sixth frequency component f6 is smaller than the amplitude of the
first frequency component f0. The amplitude of the sixth frequency
component f6 is smaller than the amplitude of the fifth frequency
component f5.
[0111] When a waveform of a mixed state is subtracted from a
waveform of the base state, the second frequency component f1, the
fifth frequency component f5 and the sixth frequency component f6
only remain. The amplitude of the second frequency component f1
remaining after the subtraction may correspond to a finger touch
sensitivity. Moreover, the amplitude of the fifth frequency
component f5 remaining after the subtraction may correspond to a
touch sensitivity of the stylus pen. Moreover, the amplitude of the
sixth frequency component f6 remaining after the subtraction may
correspond to a pen pressure sensitivity of the stylus pen.
[0112] Thus, since the second frequency component f1 is detected
corresponding to the second sensing electrode RX1, the second
driving electrode TX1 delivering a second driving signal STX1
having the second frequency component f1 and the second sensing
electrode RX1 are detected as touch coordinates of a finger.
Moreover, since the fifth frequency component f5 is detected
corresponding to the second sensing electrode RX1, it may be
confirmed that a stylus pen is disposed on the second sensing
electrode RX1. Therefore, the second sensing electrode RX1 is
detected as a first axis coordinate of the stylus pen.
[0113] The touch coordinates by the finger and the touch
coordinates by the stylus pen may be recognized in the
above-described manner, and a more detailed description will be
described with reference to FIGS. 11A to 13 described later.
[0114] FIG. 11A and FIG. 11B are configuration diagrams of a touch
sensing device illustrating a touch coordinates recognition of a
finger and a stylus pen. In particular, FIG. 11A is a configuration
diagram of a touch sensing device illustrating a sensing of a
finger coordinates, a X-coordinate of a stylus pen and a pen
pressure information of the stylus pen, and FIG. 11B is a
configuration diagram of a touch sensing device illustrating a
sensing of a Y-coordinate of a stylus pen and a pen pressure
information of the stylus pen.
[0115] FIG. 11A and FIG. 11B, a touch panel 110 includes a first
driving electrode TX0, a second driving electrode TX1, a third
driving electrode TX2 and a fourth driving electrode TX1 arranged
in a horizontal direction, and includes a first sensing electrode
RX0, a second sensing electrode RX1, a third sensing electrode RX2
and a fourth sensing electrode RX3 arranged in a longitudinal
direction. For convenience of explanation, it is shown that a touch
panel 110 of a 4.times.4 matrix in which four driving electrodes
and four sensing electrodes are disposed.
[0116] In the touch panel 110, the driving electrodes are
orthogonally arranged to intersect with and overlap each of the
sensing electrodes. Thus, each driving electrode is capacitively
coupled to each of the sensing electrodes. For example, the second
driving electrode TX1 is capacitively coupled to the second sensing
electrode RX1 at a point where the second driving electrode TX1 and
the second sensing electrode RX1 are overlapped with each other.
The intersections of the driving electrodes and the sensing
electrodes form a capacitive sensing element, respectively.
[0117] Due to a capacitive coupling between the driving electrode
and the sensing electrodes, supplying a driving signal at each
driving electrode may induce a current in each of the sensing
electrodes. For example, when a driving signal is applied to a
second driving electrode TX1, a driving signal induces a sensing
signal on a second sensing electrode RX1 in the touch panel 110.
Then, the sensing signal on each of the sensing electrodes may be
sequentially measured by using a multiplexer in order to
sequentially connect each of the sensing electrodes to a
demodulation circuit. A capacitance associated with each
intersection point between a driving electrode and a sensing
electrode may be sensed by selecting each available combination of
a driving electrode and a sensing electrode.
[0118] When a touch object such as a finger or a stylus approaches
the touch panel 110, the object causes a reduction of capacitance,
which affects only a part of the electrodes. For example, when a
finger is positioned near an intersection of a second driving
electrode TX1 and a second sensing electrode RX1, a presence of the
finger reduces a coupling capacitance between the second driving
electrode TX1 and the second sensing electrode RX1. In another
exemplary embodiment, the presence of the finger increases the
coupling capacitance between the second driving electrode TX1 and
the second sensing electrode RX1. Thus, a position of a finger on
the touch panel 110 may be determined by identifying a sensing
electrode having a reduced coupling capacitance between the sensing
electrode and the driving electrode to which the driving signal is
applied when the reduced capacitance is measured on the sensing
electrode. Thus, the capacitances associated with each intersection
of the electrodes in the touch panel 110 are sequentially
determined, so that positions of one or more inputs may be
determined.
[0119] In the present exemplary embodiment, although the driving
electrodes and sensing electrodes are shown as bars or elongated
rectangles, alternative embodiments may be used to form a variety
of mosaic shapes such as a diamond shape, a square shape, a gull
shape, and other available shapes.
[0120] The touch sensing controller 120 outputs a plurality of
driving signals having different frequency components to the touch
panel 110 and determines at least one of touch coordinates of a
finger and touch coordinates of a stylus pen based on the plurality
of sensing signals provided from the touch panel 110. The touch
sensing controller 120 may be implemented as one or a plurality of
chips.
[0121] The touch sensing controller 120 includes a touch driving
unit 122, a touch sensing unit 124, a touch determining unit 126
and a touch control unit 128.
[0122] The touch driving unit 122 is connected to driving
electrodes TX0, TX1, TX2 and TX3 of the touch panel 110 that are in
contact with a stylus pen that outputs a pen frequency signal set
to detect a position of the stylus pen and a pressure of the stylus
pen. The touch driving unit 122 outputs the driving signals to the
driving electrodes TX0, TX1, TX2 and TX3.
[0123] The touch driving unit 122 includes a transmission signal
generating part 1222 and a transmission multiplexing part 1224. The
transmission signal generating part 1222 includes a plurality of
transmission signal generators generating driving signals having
different frequency components.
[0124] The transmission multiplexing part 1224 includes a plurality
of transmission multiplexers having a first transmission input
terminal (0) connected to the transmission signal generator, a
second transmission input terminal (1) connected to the touch
sensing unit 124 and a transmission output terminal connected to
the driving electrode. The first transmission input terminal is
connected to the transmission output terminal or the second
transmission input terminal is connected to the transmission output
terminal in response to a multiplexer control signal MUXC provided
from the touch control unit 128.
[0125] The touch sensing unit 124 is connected to sensing
electrodes RX0, RX1, RX2 and RX3 of the touch panel 110 to receive
the sensing signals through the sensing electrodes RX0, RX1, RX2
and RX3.
[0126] The touch sensing unit 124 includes a reception multiplexing
part 1242, a reception sensing part 1244, an analog-to-digital
converting part 1246 and a fast Fourier transform part 1248.
[0127] The reception multiplexing part 1242 includes a plurality of
reception multiplexers having a reception output terminal, a first
reception input terminal (0) connected to the sensing electrode and
a second reception connection terminal (1) connected to a second
transmission input terminal (1) of a transmission multiplexing part
1224 of the touch driving unit 122. In response to the multiplexer
control signal MUXC, the first reception input terminal is
connected to the reception output terminal or the second reception
input terminal is connected to the reception output terminal.
[0128] The reception sensing part 1244 includes a plurality of
reception sensors connected to a reception output terminal of the
reception multiplexers.
[0129] The analog-to-digital converting part 1246 digitally
converts the sensing signals received through the reception sensors
to provide the converted signals to the fast Fourier transform part
1248. The analog-to-digital converting part 1246 performs the ADC
conversion at a frequency at least two times faster than the
driving frequency.
[0130] The fast Fourier transform part 1248 performs fast Fourier
transform each of the digitally converted sensing signals to
convert each of the sensing signals into a frequency domain in a
time domain. The fast Fourier transform part 1248 obtains a
frequency component and the magnitude of the frequency component to
provide the frequency component and the magnitude of the frequency
component to the touch determining unit 126. In the present
exemplary embodiment, by converting the sensing in the time domain
into the sensing in the frequency domain, it is very useful for
digital signal processing.
[0131] The touch determining unit 126 determines at least one of
touch coordinates of a finger, touch coordinates of a stylus pen
and a pen pressure information of the stylus pen based on a
variation amount between frequency amplitudes of the fast
Fourier-transformed sensing signal based on a frequency amplitude
of a driving signal.
[0132] The touch control unit 128 controls an operation of the
touch driving unit 122 such that driving signals having different
frequency components are simultaneously supplied to the driving
electrodes.
[0133] The touch control unit 128 provides information about a
frequency of the driving signal to the analog-to-digital converting
part 1246 so that the analog-to-digital converting part 1246
converts a frequency of the driving signal to a frequency faster
than the frequency of the driving signal.
[0134] In the present embodiment, the touch sensing controller 120
may further include one or more memory devices (not shown) for
storing measured sizes and associated parameters, and a
microprocessor (not shown) for performing the necessary computation
and control functions.
[0135] In order to perform one or more of the functions described
herein, other portions of the touch sensing controller 120 and/or
the touch sensing device 100 may be realized as one or more
application-specific integrated circuits (ASICs),
application-specific standard product (ASSP) or the like.
[0136] In operation, as shown in FIG. 11A, in response to the
multiplexer control signal MUXC, first input terminals (0) of the
transmission multiplexers and the driving electrodes are connected
to each other and first input terminals (0) the reception
multiplexers and the reception sensing part 1244 are connected to
each other, so that a touch coordinates of the finger, a first axis
coordinate of the stylus pen and a pen pressure information of the
stylus pen are sensed. In FIG. 11A, since the sensing electrodes
RX0, RX1, RX2 and RX3 are arranged along a X-axis, a first axis
coordinate of the stylus pen is a X coordinate.
[0137] Moreover, as shown in FIG. 11B, in response to the
multiplexer control signal MUXC, second input terminals (1) of the
transmission multiplexers and the driving electrode are connected
to each other and second input terminal (1) of the reception
multiplexers and reception sensing part 1244 are connected to each
other, so that a second axis coordinate of the stylus pen and a pen
pressure information of the stylus pen are sensed. In FIG. 11B,
since the driving electrodes TX0, TX1, TX2 and TX3 are arranged
along a Y-axis, a second axis coordinate of the stylus pen is a Y
coordinate.
[0138] As described above, the touch sensing controller 120 outputs
a plurality of driving signals having different frequency
components to the touch panel 110 and determines at least one of
touch coordinates of a finger and touch coordinates of a stylus pen
based on the sensing signals received at the touch panel 110, so
that the touch recognition may be realized at the same time.
[0139] FIG. 12 is a flowchart illustrating a touch coordinate
recognition method in which the finger and the stylus pen are
individually recognized in the touch sensing device shown in FIG.
11A and FIG. 11B.
[0140] Referring to FIG. 11A, FIG. 11l and FIG. 12, the multiplexer
is set to 0 (step S100). That is, first transmission input
terminals (0) of the transmission multiplexers included in the
transmission multiplexing part 1224 and the driving electrodes TX0,
TX1, TX2 and TX3 are connected to each other, and first reception
input terminals (0) of reception multiplexers included in the
reception multiplexing part 1242 and the sensing electrodes RX0,
RX1, RX2 and RX3 are connected to each other.
[0141] Then, the driving signals are transmitted to the driving
electrodes TX0, TX1, TX2 and TX3, and the sensing signals are
received through the sensing electrodes RX0, RX1, RX2 and RX3 (step
S102).
[0142] Then, it is checked whether or not the pen frequency
component is detected by fast Fourier transforming the sensing
signals (step S104). The pen frequency component includes pen
X-axis position information (e.g., the fifth frequency component
f4) and pen pressure information (e.g., the sixth frequency
component f5).
[0143] When it is checked that the pen frequency components f4 and
f5 are sensed in step S104, the pen X-axis position information
(e.g., the fifth frequency component f4) is stored and the pen
pressure information of the pen (e.g., the sixth frequency
component f5) is stored (step S106).
[0144] Then, the multiplexer is set to 1 (step S108). That is, the
second transmission input terminal (1) of the transmission
multiplexers included in the transmission multiplexing part 1224
and the driving electrodes TX0, TX1, TX2 and TX3 are connected to
each other, and the second reception input terminal (1) of the
reception multiplexers included in the reception multiplexing part
1242 and the sensing electrodes RX0, RX1, RX2 and RX3 are connected
to each other.
[0145] Then, the sensing signals received through the sensing
electrodes RX0, RX1, RX2 and RX3 are FFT-processed to check whether
or not the pen frequency components f4 and f5 are sensed (step
S110).
[0146] When it is checked that the pen frequency components f4 and
f5 are sensed in step S110, the pen Y-axis position information f4
is stored and the pen pressure information f5 is stored (step
S112).
[0147] Then, the pen coordinate (X, Y) and the pen pressure
information are reported (step S114). The pen coordinate (X. Y) is
the pen X-axis position information f4 stored in step S106 and the
pen Y-axis position information f4 stored in step S112. The pen
pressure information f5 of the pen may be the pen pressure
information f5 of the pen stored in step S106 or the pen pressure
information f5 of the pen stored in step S112.
[0148] Then, after the multiplexer is set to 0 (step S116), it is
fed back to step S104. That is, the first transmission input
terminal (0) of the transmission multiplexers included in the
transmission multiplexing part 1224 and the driving electrodes TX0,
TX1, TX2 and TX3 are connected to each other, and it is fed back to
step S104 after connecting the first reception input terminal (0)
of the reception multiplexers included in the reception
multiplexing part 1242 and the sensing electrodes RX0, RX1, RX2 and
RX3 to each other.
[0149] Meanwhile, when it is checked that the pen frequency
components f4 and f5 are not sensed in step S104, RX sensing is
performed (that is, a FFT processing) to check whether or not the
transmission frequency components f0 to f3 are sensed (step
S120).
[0150] When it is checked that the transmission frequency
components f0, f1, f2 and f3 are not sensed in step S120, it is fed
back to step S102. When it is checked that the transmission
frequency components f0, f1, f2 and f3 are sensed in step S120, the
touch coordinates of a finger is stored (step 122), and the stored
finger coordinates is reported (step S124).
[0151] FIG. 13 is a flowchart illustrating a touch coordinate
recognition method in which the finger and the stylus pen are
simultaneously recognized in the touch sensing device shown in FIG.
11A and FIG. 11B.
[0152] Referring to FIG. 11A, FIG. 11B and FIG. 13, the multiplexer
is set to 0 (step S200). That is, the first transmission input
terminal (0) of the transmission multiplexers included in the
transmission multiplexing part 1224 and the driving electrodes TX0,
TX1, TX2 and TX3 are connected to each other, and the first
reception input terminal (0) of the reception multiplexers included
in the reception multiplexing part 1242 and the sensing electrodes
RX0, RX1, RX2 and RX3 are connected to each other.
[0153] Then, the driving signals are transmitted to the driving
electrodes TX0, TX1, TX2 and TX3, and the sensing signals are
received through the sensing electrodes RX0, RX1, RX2 and RX3 (step
S202).
[0154] Then, it is checked whether or not the pen frequency
components f0, f1, f2, f3, f4 and f5 are sensed by fast Fourier
transforming the sensing signals (step S204).
[0155] When it is checked that the pen frequency components f0 to
f5 are not sensed in step S204, it is fed back to step S202.
[0156] When it is checked that the pen frequency components f0, f1,
f2, f3, f4 and f5 are sensed in step S204, the pen X-axis position
information f4 is stored and the pen pressure information f5 is
stored (step S206).
[0157] Then, the multiplexer is set to 1 (step S208). That is, the
second transmission input terminal (1) of the transmission
multiplexers included in the transmission multiplexing part 1224
and the driving electrodes TX0, TX1, TX2 and TX3 are connected to
each other, and the second reception input terminal (1) of the
reception multiplexers included in the reception multiplexing part
1242 and the sensing electrodes RX0, RX1, RX2 and RX3 are connected
to each other.
[0158] Then, the sensing signals received through the sensing
electrodes RX0, RX1, RX2 and RX3 are FFT-processed to check whether
or not the pen frequency components f4 and f5 are sensed (step
S210).
[0159] When it is checked that the pen frequency components f4 and
f5 are sensed in step S210, the pen Y-axis position information f4
is stored and the pen pressure information f5 is stored (step
S212).
[0160] Then, finger coordinate information, pen coordinate
information and pen pressure information are reported (step S214),
and then it is feedback to step S200. The finger coordinate (X,Y)
information is the pen X-axis coordinate stored at step S206 and
the pen Y-axis coordinate stored at step S212. The pen pressure
information may be the pen pressure information f5 stored in step
S206 or the pressure information f5 stored in step S212.
[0161] Although the operations of the method(s) herein are shown
and described in a particular order, the operations of each method
may be varied such that certain operations may be performed in
reverse order, or that a particular operation may be performed at
least partially concurrently with other operations. In other
exemplary embodiments, the instructions or sub-actions of the
individual operations may be intermittent and/or alternate.
[0162] Having described exemplary embodiments of the present
invention, it is further noted that it is readily apparent to those
of reasonable skill in the art that various modifications may be
made without departing from the spirit and scope of the invention
which is defined by the metes and bounds of the appended
claims.
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