U.S. patent application number 12/755660 was filed with the patent office on 2011-03-10 for display device including touch panel device, and coupling-noise eliminating method.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Nam-Hee GOO, Bo-Ram KIM, Myoung-Chul KIM, Yun-Jae KIM, Byoung-Jun LEE.
Application Number | 20110057890 12/755660 |
Document ID | / |
Family ID | 43647364 |
Filed Date | 2011-03-10 |
United States Patent
Application |
20110057890 |
Kind Code |
A1 |
GOO; Nam-Hee ; et
al. |
March 10, 2011 |
DISPLAY DEVICE INCLUDING TOUCH PANEL DEVICE, AND COUPLING-NOISE
ELIMINATING METHOD
Abstract
A display device includes; a touch panel device including; a
touch panel and a touch controller connected to the touch panel,
the touch controller including; a sampling unit which samples a
sensing output signal input thereto from the touch panel to
generate a sampled signal, and an analog/digital converter which
converts the sampled signal to generate contact information, and a
display panel device including; a display panel, a gate driver
which applies a gate signal to the display panel, and a data driver
which applies a data voltage to the display panel, wherein the
sampling unit samples a portion of the sensing output signal which
does not include a coupling noise.
Inventors: |
GOO; Nam-Hee; (Gunsan-si,
KR) ; KIM; Bo-Ram; (Asan-si, KR) ; KIM;
Myoung-Chul; (Dongducheon-si, KR) ; LEE;
Byoung-Jun; (Cheonan-si, KR) ; KIM; Yun-Jae;
(Asan-si, KR) |
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon-si
KR
|
Family ID: |
43647364 |
Appl. No.: |
12/755660 |
Filed: |
April 7, 2010 |
Current U.S.
Class: |
345/173 |
Current CPC
Class: |
G06F 3/041 20130101;
G06F 3/0412 20130101; G06F 3/04184 20190501; G06F 3/04182 20190501;
G06F 3/0418 20130101 |
Class at
Publication: |
345/173 |
International
Class: |
G06F 3/041 20060101
G06F003/041 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 8, 2009 |
KR |
10-2009-0084546 |
Claims
1. A display device comprising: a touch panel device comprising: a
touch panel; and a touch controller connected to the touch panel,
the touch controller comprising: a sampling unit which samples a
sensing output signal input thereto from the touch panel to
generate a sampled signal; and an analog/digital converter which
converts the sampled signal to generate contact information; and a
display panel device comprising: a display panel; a gate driver
which applies a gate signal to the display panel; and a data driver
which applies a data voltage to the display panel, wherein the
sampling unit samples a portion of the sensing output signal which
does not include a coupling noise.
2. The display device of claim 1, wherein the coupling noise is in
synchronization with at least one of a clock signal which generates
the gate signal and a clock signal which generates the data
signal.
3. The display device of claim 1, wherein the sampling unit samples
the sensing output signal using a sampling enable signal, and the
sampling enable signal includes a first voltage corresponding to
the coupling noise of the sensing output signal and a second
voltage corresponding to a portion of the sensing output signal
without the coupling noise.
4. The display device of claim 3, wherein the display panel device
further includes a signal controller which controls the gate driver
and the data driver, and the sampling enable signal is generated in
the signal controller using at least one of a clock signal which
generates the gate signal and a clock signal which generates the
data signal.
5. The display device of claim 3, wherein the touch controller
further includes a signal generator that receives at least one of a
clock signal which generates the gate signal and the gate signal
and the touch controller generates the sampling enable signal.
6. The display device of claim 1, wherein the touch controller
further includes a register which stores sampling time information
corresponding to information for a time that the sensing output
signal is sampled, and the sampling unit samples for the portion of
the sensing output signal without the coupling noise using the
sampling time information.
7. The display device of claim 6, wherein the sampling time
information is generated by synchronizing at least one of a clock
signal which generates the gate signal and the gate signal with the
sensing output signal, and a period of the sensing output signal is
an integer multiple of one horizontal period.
8. A display device comprising: a touch panel device comprising: a
touch panel; and a touch controller connected to the touch panel,
the touch controller comprising: a noise removing unit which
removes a coupling noise from a sensing output signal input thereto
from the touch panel and which outputs a noise-free sensing output
signal; a sampling unit which samples the noise-free sensing output
signal to generate a sampled signal; and an analog/digital
converter which converts the sampled signal to generate contact
information; and a display panel device comprising: a display
panel; a gate driver which applies a gate signal to the display
panel; and a data driver which applies a data voltage to the
display panel, wherein the noise removing unit receives a reference
noise signal from the touch panel and generates the noise-free
sensing output signal by subtracting the reference noise signal
from the sensing output signal.
9. The display device of claim 8, wherein the coupling noise is in
synchronization with at least one of a clock signal which generates
the gate signal and the gate signal, and the reference noise signal
includes a reference voltage including about 0 V and the coupling
noise.
10. The display device of claim 8, wherein the touch panel is
disposed substantially opposite to the display panel, the touch
panel includes a touch region for sensing a touch and a reference
noise extracting region electrically separated from the touch
region, the touch region includes a first electrode which outputs
the sensing output signal, and the reference noise extracting
region includes a second electrode which receives a reference
voltage including about 0 V and which outputs the reference noise
signal to the touch controller.
11. The display device of claim 10, wherein the touch region
includes a plurality of x-axis electrodes and a plurality of y-axis
electrodes insulated from and disposed substantially perpendicular
to the plurality of x-axis electrodes, the sensing output signal is
output from a first x-axis electrode of the plurality of x-axis
electrodes and a first y-axis electrode of the plurality of y-axis
electrodes that correspond to a touch point of the touch panel, and
the reference noise signal is output from at least one of the
plurality of x-axis electrodes except the first x-axis electrode
and at least one of the plurality of y-axis electrodes except the
first y-axis electrode.
12. A display device comprising: a touch panel device comprising: a
touch panel; and a touch controller connected to the touch panel,
the touch controller comprising: a noise removing unit; a sampling
unit connected to the noise removing unit; and an analog/digital
converter connected to the sampling unit; and a display panel
device comprising: a display panel; a gate driver which applies a
gate signal to the display panel; and a data driver which applies a
data voltage to the display panel, wherein the touch controller
inputs a sensing input signal and an inversion sensing input
signal, which is inverted with respect to the sensing input signal,
to the touch panel, and receives a sensing output signal
corresponding to the sensing input signal and an inversion sensing
output signal corresponding to the inversion sensing input signal
from the touch panel, the noise removing unit removes a coupling
noise from the sensing output signal to generate a noise-free
sensing output signal, the sampling unit samples the noise-free
sensing output signal to generate a sampled signal, and the
analog/digital converter converts the sampled signal to generate
contact information, and the noise removing unit generates the
noise-free sensing output signal by subtracting the inversion
sensing output signal from the sensing output signal and dividing
the subtraction result in half.
13. A display device comprising: a touch panel device comprising: a
touch panel; and a touch controller connected to the touch panel,
the touch controller comprising: a sampling unit which samples a
sensing output signal input thereto from the touch panel to
generate a sampled signal; a filter which generates a coupling
noise removed signal by removing a coupling noise from the sampled
signal; and an analog/digital converter which converts the coupling
noise removed signal to generate contact information; and a display
panel device comprising: a display panel; a gate driver which
applies a gate signal to the display panel; and a data driver which
applies a data voltage to the display panel.
14. The display device of claim 13, wherein the sampled signal
includes a plurality of extracted data in series, the filter
compares the plurality of extracted data with each other, and the
filter compares a value of a first data of the plurality of
extracted data with a value of a previous data of the first data
and a value of a next data of the first data among the plurality of
extracted data, and removes the first data from the plurality of
extracted data when a difference between a value of the first data
and a value of the previous data, or a difference between the value
of the first data and a value of the next data, is equal to or
greater than a predetermined value.
15. A method for eliminating a coupling noise of a display device,
the display device including a touch panel device including a touch
panel and a touch controller, and a display panel device including
a display panel, a gate driver which applies a gate signal to a
display panel, and a data driver which applies a data voltage to
the display panel, the method comprising: receiving a sensing
output signal including a coupling noise from the touch panel;
sampling a portion of the sensing output signal without the
coupling noise to generate a sampled signal; and generating contact
information by converting the sampled signal.
16. The method of claim 15, wherein the coupling noise is in
synchronization with at least one of a clock signal for generating
the gate signal and the gate signal.
17. The method of claim 15, wherein the sampling for the portion of
the sensing output signal without the coupling noise to generate
the sampled signal comprises using a sampling enable signal, and
the sampling enable signal includes a first voltage corresponding
to the coupling noise of the sensing output signal and a second
voltage corresponding to a portion of the sensing output signal
without the coupling noise.
18. The method of claim 17, wherein the display panel device
further includes a signal controller which controls the gate driver
and the data driver, and the sampling enable signal is generated in
the signal controller using at least one of a clock signal which
generates the gate signal and the gate signal.
19. The method of claim 17, wherein the touch controller further
comprises a signal generator which generates the sampling enable
signal by receiving at least one of a clock signal which generates
the gate signal and the gate signal.
20. The method of claim 15, wherein the sampling for the portion of
the sensing output signal without the coupling noise to generate
the sampled signal comprises using sampling time information
corresponding to information for a time that the sensing output
signal is sampled, and the touch controller further includes a
register which stores the sampling time information.
21. The method of claim 20, wherein the sampling time information
is generated by synchronizing at least one of a clock signal which
generates the gate signal and the gate signal with the sensing
output signal, and a period of the sensing output signal is an
integer multiple of one horizontal period.
22. A method for eliminating a coupling noise of a display device
including a touch panel device including a touch panel and a touch
controller, and a display panel device including a display panel, a
gate driver which applies a gate signal to the display panel, and a
data driver which applies a data voltage to the display panel, the
method comprising: receiving a sensing output signal including a
coupling noise, and a reference noise signal from the touch panel;
generating a noise-free sensing output signal by subtracting the
reference noise signal from the sensing output signal to remove the
coupling noise from the sensing output signal; sampling the
noise-free sensing output signal to generate a sampled signal; and
generating contact information by converting the sampled
signal.
23. The method of claim 22, wherein the coupling noise is in
synchronization with at least one of a clock signal which generates
the gate signal and the gate signal, and the reference noise signal
includes a reference voltage including 0V and the coupling
noise.
24. The method of claim 22, wherein the touch panel is disposed
substantially opposite to the display panel, the touch panel
includes a touch region which senses a touch and a reference noise
extracting region electrically separated from the touch region, the
touch region includes a first electrode which outputs the sensing
output signal, and the reference noise extracting region is applied
with a reference voltage including about 0 V, and includes a second
electrode which outputs the reference noise signal to the touch
controller.
25. The method of claim 22, wherein the touch region includes a
plurality of x-axis electrodes and a plurality of y-axis electrodes
insulated from and disposed substantially perpendicular to the
x-axis electrodes, the sensing output signal is output from a first
x-axis electrode and a first y-axis electrode corresponding to a
touch point of the touch panel among the plurality of x-axis
electrodes and the plurality of y-axis electrodes, and the
reference noise signal is output from at least one of the plurality
of x-axis electrodes except the first x-axis electrode and from at
least one of the plurality of y-axis electrodes except the first
y-axis electrode.
26. A method for eliminating a coupling noise of a display device
including a touch panel device including a touch panel and a touch
controller, and a display panel device including a display panel, a
gate driver which applies a gate signal to the display panel, and a
data driver which applies a data voltage to the display panel, the
method comprising: inputting a sensing input signal and an
inversion sensing input signal, which is an inverted signal of the
sensing input signal, to the touch panel; receiving a sensing
output signal corresponding to the sensing input signal, and an
inversion sensing output signal corresponding to the inversion
sensing input signal from the touch panel; generating a noise-free
sensing output signal by subtracting the inversion sensing output
signal from the sensing output signal and dividing the subtraction
result in half; generating a sampled signal by sampling the
noise-free sensing output signal; and generating contact
information by converting the sampled signal.
27. A method for eliminating a coupling noise of a display device
including a touch panel device including a touch panel and a touch
controller, and a display panel device including a display panel, a
gate driver which applies a gate signal to the display panel, and a
data driver which applies a data voltage to the display panel, the
method comprising: receiving a sensing output signal including a
coupling noise from the touch panel; generating a sampled signal by
sampling the sensing output signal; generating a coupling noise
removed signal by removing the coupling noise from the sampled
signal; and generating contact information by converting the
coupling noise removed signal.
28. The method of claim 27, wherein the sampled signals include a
plurality of extracted data in series, the removing of the coupling
noise from the sampled signal comprises: comparing a value of a
first data of the plurality of extracted data with a value of a
previous data of the first data and a value of a next data of the
first data among the plurality of extracted data; and removing the
first data from the plurality of extracted data when a difference
between a value of the first data and a value of the previous data
or a difference between the value of the first data and a value of
the next data is equal to or greater than a predetermined value.
Description
[0001] This application claims priority to Korean Patent
Application No. 10-2009-0084546, filed on Sep. 8, 2009, and all the
benefits accruing therefrom under 35 U.S.C. .sctn.119, the content
of which in its entirety is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] (a) Field of the Invention
[0003] The present invention relates to a display device including
a touch panel device, and a method for eliminating a coupling noise
between the display device and the touch panel device.
[0004] (b) Description of the Related Art
[0005] A display device of a liquid crystal display ("LCD") and an
organic light emitting device ("OLED"), a portable transmitting
device, and other types of information processing devices execute a
function thereof using various input devices, e.g., keyboards,
mice, etc. Recently, the use of touch panels as an input device has
increased.
[0006] The typical touch panel is a device for allowing a machine
such as a computer to perform a desired command by writing a
character, drawing a picture, or executing an icon through touching
a finger or a touch pen (such as a stylus) on a screen. A display
device to which the touch panel is attached can determine whether
the finger of a user or a touch pen, etc., touches a screen, and
touch position information thereof (the touch determination, i.e.,
the determination of whether a touch event occurred, and the
positional information regarding the touch event may collectively
be referred to as a "touch input"). The display device may then
display images according to the position of the touch input.
[0007] These touch panels are typically classified as a resistive
type, a capacitive type and an electro-magnetic ("EM") type
according to the method by which the touch is sensed.
[0008] Among the various types of touch panels, the resistive type
of touch panel typically includes upper and lower transparent
electrodes separated from each other by a spacer. If an upper plate
formed with the upper transparent electrode is depressed by
external contact such that the upper transparent electrode and the
lower transparent electrode physically contact each other, the
contact and the position of the contact may be determined by
measuring a voltage change according to the resistance of the
depressed position. The resistive type of touch panel may be
operated regardless of the conductivity of the contact matter,
however when several positions are simultaneously touched, the
values of the changed voltages are recognized jointly as one
contact such that it is difficult to obtain simultaneous touch
information from the several positions.
[0009] The capacitance type of touch panel typically includes a
film formed with a transparent electrode, and touch determination
and touch positions may be determined by measuring a voltage change
of the conductive matter by the user contact after applying a
voltage to the transparent electrode. The user contact in this type
of touch panel is typically supplied by the finger of the user.
This capacitance type touch panel may determine the contact
existence and the contact position even if various positions are
simultaneously contacted, however the voltage change is not
generated when an insulator, such as gloves or other non-conductive
surface, contact the touch panel such that the contact information
may not be obtained.
[0010] The touch panel may be further classified into an external
type in which the touch panel is attached to an outside of the
display device and an embedded type in which the touch panel is
located inside the display device itself.
[0011] A display panel of the display device may include a
plurality of switching elements for switching a data voltage, and a
plurality of signal lines, such as gate lines and data lines, for
applying the data voltage to a plurality of pixels by controlling
the switching elements. The gate lines transmit a gate signal
including a gate-on voltage Von and a gate-off voltage Voff.
Signals applied to the display panel, and especially signals having
relatively large widths such as the gate signal, influence a
sensing output signal of both the embedded and external touch
panel, thereby generating unwanted coupling noise which
deteriorates the quality of the associated display.
BRIEF SUMMARY OF THE INVENTION
[0012] The present invention eliminates coupling noise included in
a sensing output signal of a touch panel device.
[0013] An exemplary embodiment of a display device according to a
the present invention includes; a touch panel device including a
touch panel and a touch controller; and a display panel device
including a display panel, a gate driver which applies a gate
signal to the display panel, and a data driver which applies a data
voltage to the display panel, wherein the touch controller includes
a sampling unit that samples a sensing output signal inputted from
the touch panel to generate a sampled signal and an analog/digital
("A/D") converter which converts the sampled signal to generate
contact information, and the sampling unit samples for a portion of
the sensing output signal which does not include a coupling
noise.
[0014] In one exemplary embodiment, the coupling noise may be in
synchronization with at least one of a clock signal which generates
the gate signal and the gate signal.
[0015] In one exemplary embodiment, the sampling unit may sample
the sensing output signal by using a sampling enable signal, and
the sampling enable signal may include a first voltage
corresponding to a coupling noise of the sensing output signal, and
a second voltage corresponding to a portion without the coupling
noise.
[0016] In one exemplary embodiment, the display panel device may
further include a signal controller for controlling the gate driver
and the data driver, and the sampling enable signal may be
generated in the signal controller by using at least one of a clock
signal which generates the gate signal and the gate signal.
[0017] In one exemplary embodiment, the touch controller may
further include a signal generator receiving at least one of a
clock signal which generates the gate signal and the gate signal
and generates the sampling enable signal.
[0018] In one exemplary embodiment, the touch controller may
further include a register for storing sampling time information as
information for a time that the sensing output signal is sampled,
and the sampling unit may execute the sampling for the portion of
the sensing output signal without the coupling noise by using the
sampling time information.
[0019] In one exemplary embodiment, the sampling time information
may be generated by synchronizing at least one of a clock signal
which generates the gate signal and the gate signal with the
sensing output signal, and a period of the sensing output signal
may be an integer multiple of 1 horizontal period 1H.
[0020] Another exemplary embodiment of a display device according
to the present invention includes: a touch panel device including a
touch panel and a touch controller; and a display panel device
including a display panel, a gate driver which applies a gate
signal to the display panel, and a data driver which applies a data
voltage to the display panel, wherein the touch controller includes
a noise removing unit for removing a coupling noise from the
sensing output signal inputted from the touch panel and for
outputting a noise-free sensing output signal, a sampling unit for
sampling the noise-free sensing output signal to generate a sampled
signal, and an A/D converter which converts the sampled signal to
generate contact information, and the noise removing unit further
receives a reference noise signal from the touch panel and
generates the noise-free sensing output signal by subtracting the
reference noise signal from the sensing output signal.
[0021] In one exemplary embodiment, the coupling noise may be in
synchronization with at least one of a clock signal which generates
the gate signal and the gate signal, and the reference noise signal
may include a reference voltage including 0V and the coupling
noise.
[0022] In one exemplary embodiment, the touch panel may face the
display panel, the touch panel may include a touch region for
sensing a touch and a reference noise extracting region
electrically separated from the touch region, the touch region may
include a first electrode for outputting the sensing output signal,
and the reference noise extracting region may include a second
electrode for receiving a reference voltage including 0V and for
outputting the reference noise signal to the touch controller.
[0023] In one exemplary embodiment, the touch region may include a
plurality of x-axis electrodes and a plurality of y-axis electrodes
insulated from and disposed substantially perpendicular to the
x-axis electrodes, the sensing output signal may be output from a
first x-axis electrode and a first y-axis electrode that correspond
to a touch point of the touch panel among the plurality of x-axis
electrodes and the plurality of y-axis electrodes, and the
reference noise signal may be output from at least one of the
plurality of x-axis electrodes except the first x-axis electrode
and at least one of the plurality of y-axis electrodes except the
first y-axis electrode.
[0024] Another exemplary embodiment of a display device according
to the present invention includes a touch panel device including a
touch panel and a touch controller, and a display panel device
including a display panel, a gate driver applying a gate signal to
the display panel, and a data driver applying a data voltage to the
display panel. The touch controller inputs a sensing input signal
and an inversion sensing input signal that is an inverted signal of
the sensing input signal to the touch panel, and receives a sensing
output signal corresponding to the sensing input signal and an
inversion sensing output signal corresponding to the inversion
sensing input signal from the touch panel. The touch controller
includes a noise removing unit for removing a coupling noise from
the sensing output signal to generate a noise-free sensing output
signal, a sampling unit for sampling the noise-free sensing output
signal to generate a sampled signal, and an A/D converter which
converts the sampled signal to generate contact information. The
noise removing unit generates the noise-free sensing output signal
by subtracting the inversion sensing output signal from the sensing
output signal and dividing the subtraction result in half.
[0025] Another exemplary embodiment of a display device according
to the present invention includes a touch panel device including a
touch panel and a touch controller, and a display panel device
including a display panel, a gate driver which applies a gate
signal to the display panel, and a data driver which applies a data
voltage to the display panel. The touch controller includes a
sampling unit for sampling a sensing output signal inputted from
the touch panel to generate a sampled signal, a filter which
generates a coupling noise removed signal by removing a coupling
noise from the sampled signal, and an A/D converter which converts
the coupling noise removed signal to generate contact
information.
[0026] In one exemplary embodiment, the sampled signal may include
a plurality of extracted data in series, the filter may compare the
plurality of extracted data with each other, and the filter may
compare a value of a first data of the plurality of extracted data
with a value of previous data of the first data and a value of next
data of the first data among the plurality of extracted data, and
may remove the first data from the plurality of extracted data when
a difference between the value of the first data and the value of
the previous data or a difference between the value of the first
data and the value of the next data is equal to or more than a
predetermined value.
[0027] An exemplary embodiment of a method for eliminating a
coupling noise of a display device according to the present
invention, the display device including a touch panel device
including a touch panel and a touch controller, and a display panel
device including a display panel, a gate driver which applies a
gate signal to the display panel, and a data driver applying a data
voltage to the display panel, includes; receiving a sensing output
signal including coupling noise from the touch panel; performing
sampling for a portion of the sensing output signal without the
coupling noise to generate a sampled signal; and converting the
sampled signal to generate contact information.
[0028] In one exemplary embodiment, the coupling noise may be in
synchronization with at least one of a clock signal which generates
the gate signal and the gate signal.
[0029] In one exemplary embodiment, the executing of sampling for
the portion of the sensing output signal without the coupling noise
to generate the sampled signal may comprises using a sampling
enable signal, and the sampling enable signal may include a first
voltage corresponding to the coupling noise of the sensing output
signal and a second voltage corresponding to a portion without the
coupling noise.
[0030] In one exemplary embodiment, the display panel device may
further include a signal controller for controlling the gate driver
and the data driver, and the sampling enable signal may be
generated in the signal controller by using at least one of a clock
signal which generates the gate signal and the gate signal.
[0031] In one exemplary embodiment, the touch controller further
may include a signal generator which generates the sampling enable
signal by receiving at least one of a clock signal which generates
the gate signal and the gate signal.
[0032] In one exemplary embodiment, the performing of sampling for
the portion of the sensing output signal without the coupling noise
to generate the sampled signal may comprise using sampling time
information which is information for a time that the sensing output
signal is sampled, and the touch controller may further include a
register for storing the sampling time information.
[0033] In one exemplary embodiment, the sampling time information
may be generated by synchronizing at least one of a clock signal
which generates the gate signal and the gate signal with the
sensing output signal, and a period of the sensing output signal
may be an integer multiple of 1 horizontal period 1H.
[0034] Another exemplary embodiment of a method for eliminating a
coupling noise of a display device according to the present
invention, display device including a touch panel device including
a touch panel and a touch controller, and a display panel device
including a display panel, a gate driver applying a gate signal to
the display panel, and a data driver applying a data voltage to the
display panel includes; receiving a sensing output signal including
a coupling noise, and a reference noise signal from the touch
panel; generating a noise-free sensing output signal by subtracting
the reference noise signal from the sensing output signal to remove
the coupling noise from the sensing output signal; sampling the
noise-free sensing output signal to generate a sampled signal; and
converting the sampled signal to generate contact information.
[0035] In one exemplary embodiment, the coupling noise may be in
synchronization with at least one of a clock signal which generates
the gate signal and the gate signal, and the reference noise signal
may include a reference voltage including 0V and the coupling
noise.
[0036] In one exemplary embodiment, the touch panel may face the
display panel, the touch panel may include a touch region for
sensing a touch and a reference noise extracting region
electrically separated from the touch region, the touch region may
include a first electrode for outputting the sensing output signal,
and the reference noise extracting region may be applied with a
reference voltage including 0V and may include a second electrode
for outputting the reference noise signal to the touch
controller.
[0037] In one exemplary embodiment, the touch region may include a
plurality of x-axis electrodes and a plurality of y-axis electrodes
insulated from and disposed substantially perpendicular to the
x-axis electrodes, the sensing output signal may be output from a
first x-axis electrode and a first y-axis electrode corresponding
to a touch point of the touch panel among the plurality of x-axis
electrodes and the plurality of y-axis electrodes, and the
reference noise signal may be output from at least one of the
plurality of x-axis electrodes except the first x-axis electrode
and from at least one of the plurality of y-axis electrodes except
the first y-axis electrode.
[0038] Another exemplary embodiment of a method for eliminating a
coupling noise of a display device according to the present
invention, the display device including a touch panel device
including a touch panel and a touch controller, and a display panel
device including a display panel, a gate driver applying a gate
signal to the display panel, and a data driver applying a data
voltage to the display panel, includes; inputting to the touch
panel a sensing input signal and an inversion sensing input signal
that is an inverted signal of the sensing input signal; receiving a
sensing output signal corresponding to the sensing input signal and
an inversion sensing output signal corresponding to the inversion
sensing input signal from the touch panel; generating a noise-free
sensing output signal by subtracting the inversion sensing output
signal from the sensing output signal and dividing the subtraction
result in half; sampling the noise-free sensing output signal to
generate a sampled signal; and converting the sampled signal to
generate contact information.
[0039] Another exemplary embodiment of a method for eliminating a
coupling noise of a display device according to the present
invention, the display device including a touch panel device
including a touch panel and a touch controller, and a display panel
device including a display panel, a gate driver which applies a
gate signal to the display panel, and a data driver which applies a
data voltage to the display panel, includes; receiving a sensing
output signal including a coupling noise from the touch panel,
sampling the sensing output signal to generate a sampled signal,
removing the coupling noise from the sampled signal to generate a
coupling noise removed signal, and converting the coupling noise
removed signal to generate contact information.
[0040] In one exemplary embodiment, the sampled signals may include
a plurality of extracted data in series, the removing of the
coupling noise from the sampled signal may include comparing a
value of a first data of the plurality of extracted data with a
value of previous data of the first data and a value of next data
of the first data among the plurality of extracted data, and
removing the first data from the plurality of extracted data when a
different between the value of the first data and the value of the
previous data or a difference between the value of the first data
and the value of the next data is equal to or more than a
predetermined value.
[0041] According to the present exemplary embodiments, when the
touch panel is attached to the display panel or is embodied inside
the display panel, the coupling noise of the gate signal may be
removed such that an error generated by the coupling noise of the
contact information may be prevented. Also, touch accuracy of the
display device requiring minute touch resolution may be
improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] The above and other aspects, advantages and features of this
disclosure will become more apparent by describing in further
detail exemplary embodiments thereof with reference to the
accompanying drawings, in which:
[0043] FIG. 1 is a cross-sectional view of an exemplary embodiment
of a display device including a touch panel and a display panel
according to the present invention;
[0044] FIG. 2 is a cross-sectional view of an exemplary embodiment
of a liquid crystal display ("LCD") including an exemplary
embodiment of a touch panel and an exemplary embodiment of a liquid
crystal panel according to the present invention;
[0045] FIG. 3 is a block diagram of an exemplary embodiment of a
display panel device of a display device according to the present
invention;
[0046] FIG. 4 is a block diagram of an exemplary embodiment of a
touch panel device of a display device according to the present
invention;
[0047] FIG. 5 is a waveform diagram of a clock signal, a gate
signal, a coupling noise signal, a noise-free sensing output signal
and a sensing output signal of an exemplary embodiment of a display
device according to an exemplary embodiment of the present
invention;
[0048] FIG. 6 is an actual waveform diagram of a gate signal and a
sensing output signal of an exemplary embodiment of a display
device according to the present invention;
[0049] FIG. 7 and FIG. 8 are block diagrams of an exemplary
embodiment of a touch controller according to the present
invention;
[0050] FIG. 9 is a waveform diagram of a sensing output signal and
a sampling enable signal according to the exemplary embodiment of a
touch controller shown in FIG. 7 and FIG. 8;
[0051] FIG. 10 is a block diagram of another exemplary embodiment
of a touch controller according to the present invention;
[0052] FIG. 11 is a waveform diagram of a gate signal, a noise-free
sensing output signal, and a sensing output signal according to the
exemplary embodiment of a touch controller shown in FIG. 10;
[0053] FIG. 12 is a block diagram of another exemplary embodiment
of a touch controller according to the present invention;
[0054] FIG. 13 is a waveform diagram of a sensing output signal, a
reference noise signal, and a coupling noise removed sensing output
signal according to the exemplary embodiment of a touch controller
shown in FIG. 12;
[0055] FIG. 14 is a block diagram of an exemplary embodiment of a
touch panel device including the exemplary embodiment of a touch
controller shown in FIG. 12;
[0056] FIG. 15 is a block diagram of another exemplary embodiment
of a touch panel device including the exemplary embodiment of a
touch controller shown in FIG. 12;
[0057] FIG. 16 is a waveform diagram of a sensing output signal
according to the exemplary embodiment of a touch panel device shown
in FIG. 15;
[0058] FIG. 17 is a block diagram of an exemplary embodiment of a
touch panel device according to the present invention;
[0059] FIG. 18 is a block diagram of an exemplary embodiment of a
touch controller according to the exemplary embodiment of a touch
panel device shown in FIG. 17;
[0060] FIG. 19 is a waveform diagram of a sensing output signal, a
reversion sensing output signal, and a coupling noise removed
sensing output signal including the exemplary embodiment of a touch
panel device and touch controller shown in FIG. 17 and FIG. 18;
[0061] FIG. 20 is a block diagram of another exemplary embodiment
of a touch controller according to the present invention;
[0062] FIG. 21 is a waveform diagram of the sensing output signal
according to the exemplary embodiment of a touch controller shown
in FIG. 20; and
[0063] FIG. 22 is an enlarged view of a portion A of the sensing
output signal shown in FIG. 21.
DETAILED DESCRIPTION OF THE INVENTION
[0064] The invention now will be described more fully hereinafter
with reference to the accompanying drawings, in which embodiments
of the invention are shown. This invention may, however, be
embodied in many different forms and should not be construed as
limited to the embodiments set forth herein. Rather, these
embodiments are provided so that this disclosure will be thorough
and complete, and will fully convey the scope of the invention to
those skilled in the art. Like reference numerals refer to like
elements throughout.
[0065] It will be understood that when an element is referred to as
being on another element, it can be directly on the other element
or intervening elements may be present therebetween. In contrast,
when an element is referred to as being "directly on" another
element, there are no intervening elements present. As used herein,
the term "and/or" includes any and all combinations of one or more
of the associated listed items.
[0066] 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 element,
component, 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.
[0067] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the 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," or "includes"
and/or "including" when used in this specification, specify the
presence of stated features, regions, integers, steps, operations,
elements, and/or components, but do not preclude the presence or
addition of one or more other features, regions, integers, steps,
operations, elements, components, and/or groups thereof.
[0068] Furthermore, relative terms, such as "lower" or "bottom" and
"upper" or "top," may be used herein to describe one element's
relationship to another elements as illustrated in the Figures. It
will be understood that relative terms are intended to encompass
different orientations of the device in addition to the orientation
depicted in the Figures. For example, if the device in one of the
figures is turned over, elements described as being on the "lower"
side of other elements would then be oriented on "upper" sides of
the other elements. The exemplary term "lower", can therefore,
encompasses both an orientation of "lower" and "upper," depending
on the particular orientation of the figure. Similarly, if the
device in one of the figures is turned over, elements described as
"below" or "beneath" other elements would then be oriented "above"
the other elements. The exemplary terms "below" or "beneath" can,
therefore, encompass both an orientation of above and below.
[0069] 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 the present
disclosure, and will not be interpreted in an idealized or overly
formal sense unless expressly so defined herein.
[0070] Exemplary embodiments of the present invention are described
herein with reference to cross section illustrations that are
schematic illustrations of idealized embodiments 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, 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, a region illustrated or described as flat may, typically,
have rough and/or nonlinear features. Moreover, sharp angles that
are illustrated may be rounded. Thus, the regions illustrated in
the figures are schematic in nature and their shapes are not
intended to illustrate the precise shape of a region and are not
intended to limit the scope of the present invention.
[0071] All methods described herein can be performed in a suitable
order unless otherwise indicated herein or otherwise clearly
contradicted by context. The use of any and all examples, or
exemplary language (e.g., "such as"), is intended merely to better
illustrate the invention and does not pose a limitation on the
scope of the invention unless otherwise claimed. No language in the
specification should be construed as indicating any non-claimed
element as essential to the practice of the invention as used
herein.
[0072] Hereinafter, the present invention will be described in
detail with reference to the accompanying drawings.
[0073] Firstly, an exemplary embodiment of a display device
according to the present invention will be described with reference
to FIG. 1 to FIG. 5.
[0074] FIG. 1 is a cross-sectional view of an exemplary embodiment
of a display device including a touch panel and a display panel
according to the present invention, FIG. 2 is a cross-sectional
view of an exemplary embodiment of a liquid crystal display ("LCD")
including a touch panel and a liquid crystal panel according to the
present invention, FIG. 3 is a block diagram of an exemplary
embodiment of a display panel device of a display device according
to the present invention, FIG. 4 is a block diagram of an exemplary
embodiment of a touch panel device of a display device according to
the present invention, and FIG. 5 is a waveform diagram of a clock
signal, a gate signal, a coupling noise signal, a noise-free
sensing output signal, and a sensing output signal of an exemplary
embodiment of a display device according to the present invention,
and FIG. 6 is an actual waveform diagram of a gate signal and a
sensing output signal of an exemplary embodiment of a display
device according to the present invention.
[0075] Referring to FIG. 1, an exemplary embodiment of a display
device according to the present invention includes a display panel
device having a display panel 300, and a touch panel device having
a touch panel 10. Embodiments include configurations wherein the
touch panel 10 may be deposited on the display panel 300 or may be
attached to, e.g., integrally formed as a single, unitary and
indivisible unit with, the display panel 300.
[0076] The display panel device may be a flat panel display such as
an LCD and an organic light emitting device ("OLED"), although the
present invention is not limited thereto, and the display panel 300
may be a display panel for the flat panel display.
[0077] Referring to FIG. 3, the exemplary embodiment of a display
panel device according to the present invention includes a display
panel 300, a gate driver 400, a data driver 500 and a signal
controller 600.
[0078] As shown in an equivalent circuit view, the display panel
300 includes a plurality of signal lines G1-Gn and D1-Dm, and a
plurality of pixels PX connected thereto and arranged substantially
in a matrix shape. The signal lines G1-Gn and D1-Dm include a
plurality of gate lines G1 to Gn for transmitting gate signals
(also referred as "scanning signals") and a plurality of data lines
D1 to Dm for transmitting a plurality of data voltages. Each pixel
PX, for example the pixel PX connected to the i-th (i=1, 2, . . . ,
n) gate line Gi and the j-th (j=1, 2, . . . , m) data line Dj,
includes a switching element (not shown) connected to the gate line
Gi and the data line Dj.
[0079] The gate driver 400 is connected to the scanning lines G1-Gn
of the display panel 300 to apply a scanning signal consisting of a
combination of a gate-on voltage Von for turning on the switching
element and a gate-off voltage Voff for turning off the switching
element to the scanning lines G1-Gn.
[0080] The data driver 500 is connected to the data lines D1-D2m of
the display panel 300 to apply the data voltage to the data lines
D1-D2m.
[0081] The signal controller 600 controls the gate driver 400 and
the data driver 500. The signal controller 600 receives an input
image signal Din and an input control signal ICON for controlling
the display of the input image signal Din from an external supply
(not shown). The input image signals Din includes information about
luminance of each pixel PX, and examples of the input control
signal include a vertical synchronization signal, a horizontal
synchronizing signal, a main clock signal, a data enable signal and
various other similar signals.
[0082] Referring to FIG. 4, the exemplary embodiment of a touch
panel device according to the present invention includes a touch
panel 10 and a touch controller 20 connected thereto.
[0083] The touch panel 10 receives a sensing input signal "Sin"
from the touch controller 20, and if a contact, such as the
application of a force to the touch controller 20 via a finger of a
user, is applied to the surface of the touch panel 10, the touch
panel 10 senses the contact and the sensing output signal "Sout" is
output to the touch controller 20. The touch controller 20
processes the sensing output signal to generate the contact
information "INF" such as the coordinate of the contact position,
and the contact information INF is output to the external device
(not shown). The external device transmits the input image signal
to the display panel device based on the contact information
INF.
[0084] Referring to FIG. 2, another embodiment of a display device
according to the present invention includes the display panel
device having the display panel 300, and the touch panel device
having the touch panel 10.
[0085] The present exemplary embodiment of a display panel 300
includes a lower panel 100 and an upper panel 200 disposed
substantially opposite to each other, and a liquid crystal layer 3
interposed therebetween. Polarizers 12 and 22 are provided on the
outer surfaces of the display panel 300; embodiments include
configurations wherein the polarizers 12 and 22 are disposed
directly on the display panel 300 and configurations wherein the
polarizers 12 and 22 may be disposed such that intervening layers
are present between the polarizers 12 and 22 and the display panel
300. The transmissive axis of the two polarizers 12 and 22 may be
crossed with, e.g., substantially perpendicular to, each other, and
exemplary embodiments also include configurations wherein one of
the two polarizers 12 and 22 may be omitted.
[0086] In the exemplary embodiment shown in FIG. 2, the touch panel
10 is disposed between the display panel 300 and the polarizer 22.
Alternative exemplary embodiments include configurations wherein
the touch panel 10 may be disposed under the upper panel 200 of the
display panel 300 or may be attached outside the polarizer 22. The
exemplary embodiment in which the touch panel 10 is attached
outside the polarizer 22 may also be referred to as an external
type display device, and the exemplary embodiment in which the
touch panel 10 is attached inside the polarizer 22 may also be
referred to as the embedded type display device.
[0087] The various characteristics related to FIG. 1, FIG. 3, and
FIG. 4 may be applied to the exemplary embodiment of FIG. 2.
[0088] Now, an exemplary embodiment of the operation of the display
device will be described.
[0089] The signal controller 600 processes the input image signals
Din to convert the output image signal Dout and to generate the
gate control signal CONT1 and the data control signal CONT2, and
outputs the gate control signal CONT1 to the gate driver 400, and
outputs the data control signal CONT2 and the output image signal
Dout to the data driver 500.
[0090] Embodiments of the scan control signals CONT1 include a
scanning start signal for instructing to start scanning, and at
least one clock signal for controlling the output period of the
gate-on voltage Von.
[0091] Referring to FIG. 5, the pulse width of the clock signal CKV
is about 1 horizontal period (or "1H", which is one period of the
horizontal synchronizing signal and the data enable signal), and in
one exemplary embodiment the duty ratio may be about 50%. The clock
signal CKV swings between the high level voltage Vh and the low
level voltage V1, and when the clock signal CKV is increased to the
high level voltage Vh or is decreased to the low level voltage V1,
the gate signal is generated in synchronization therewith as
illustrated by gate signals Vg1 through Vgk. The pulse width of the
gate signal, that is the time period of the gate-on voltage Von, is
1H.
[0092] The data driver 500 receives output image signal Dout for
one row of pixels PXs according to the data control signal CONT2
from the signal controller 600 and converts the output image signal
Dout into a corresponding data voltage and then applies the
corresponding data voltage to the corresponding data lines
D1-Dm.
[0093] The gate driver 400 applies the gate-on voltage Von to a
gate line of the plurality of gate lines G1-Gn in response to the
scanning control signals CONT1 from the signal controller 600,
thereby turning on the switching element connected to the applied
gate line such that the data voltage applied to the data lines
D1-Dm is applied to the corresponding pixel through the turned-on
switching element.
[0094] After a time period of 1H, the data driver 500 and the gate
driver 400 repeat the same operation for a pixel of the next row.
In such a manner, the gate-on voltage Von is applied to all of the
gate lines G1a to Gmh during one frame, and the data voltage is
applied to all of the pixels in a row by row manner.
[0095] Referring to FIG. 5 and FIG. 6, the sensing output signal
Sout output from the touch panel 10 is influenced by the gate
signals Vg1, . . . , Vgk applied to the plurality of gate lines
(e.g., from the first gate line G1 to the k-th gate line Gk (k=1, .
. . , n)). That is, the sensing output signal Sout is coupled to
the gate signals (Vg, . . . , Vgk) such that the noise-free sensing
output signal Sout0 is added with the coupling noise signal Nc such
that the sensing output signal Sout is output when the voltage of
the gate signals Vg, . . . , Vgk is increased or decreased. The
sensing output signal Sout includes a plurality of coupling noises
Ns. While not limiting of the present invention, the coupling of
the gate signals and the sensing output signal Sout may be
capacitive coupling.
[0096] For illustrative purposes, the gate signals Vg1, . . . , Vgk
of the gate lines G1 through the k-th gate line Gk (k=1, . . . , n)
is represented by one signal in FIG. 6.
[0097] The coupling noise Ns added to the sensing output signal
Sout may be undesirably substantial when the touch panel 10 is
positioned inside the display panel 300 or attached closely to the
display panel 300 as shown in FIG. 1 and FIG. 2. If the sensing
output signal Sout with the added coupling noise Ns is sampled in
an unmodified state to obtain the contact information INF, the
value of the coupling noise may be processed such that erroneous
contact information INF corresponding to the coupling noise Ns may
be obtained.
[0098] Next, a method for eliminating a coupling noise of the touch
panel device by obtaining correct contact information INF omitting
a coupling noise of a sensing output signal Sout will be described
with reference to FIG. 7 to FIG. 9 as well as FIG. 1 to FIG. 6.
[0099] FIG. 7 and FIG. 8 are block diagrams of an exemplary
embodiment of a touch controller according to the present
invention, and FIG. 9 is a waveform diagram of a sensing output
signal and a sampling enable signal according to the exemplary
embodiment of a touch controller shown in FIG. 7 and FIG. 8.
[0100] Referring to FIG. 7, the exemplary embodiment of a touch
controller 20 of the touch panel device according to the present
invention includes a sampling unit 21 and an analog/digital ("A/D")
converter 24.
[0101] The sampling unit 21 receives a sampling enable signal SEN
from the signal controller 600 of the display panel device and
samples the sensing output signal Sout from the touch panel 10
based on the sampling enable signal SEN, and outputs the sampled
data to the A/D converter 24.
[0102] The sampling enable signal SEN, which is a signal for the
position information of the coupling noise Ns of the sensing output
signal Sout, instructs the sampling unit 21 sample the sensing
output signal Sout during a portion of the sensing output signal
Sout where the coupling noise Ns is not present. The sampling
enable signal SEN includes a low level voltage V2 and a high level
voltage V1, and may be generated by using the clock signal CKV or
the gate signals Vg1, . . . , Vgk in the signal controller 600.
[0103] As shown in FIG. 9, the sampling enable signal SEN includes
a pulse rising at a predetermined time after a rising time of the
gate signals Vg1, . . . , Vgk and falling at a predetermined time
before the next rising time of the gate signals Vg1, . . . , Vgk.
The time length between the rising time of the gate signals Vg1, .
. . , Vgk and the rising time of the pulse of the sampling enable
signal SEN or the time length between the falling time of the pulse
of the sampling enable signal SEN and the next rising time of the
gate signals Vg1, . . . , Vgk may be, for example, equal to or less
than 1/4H. That is, the time while the high level voltage V1 is
maintained may be equal to or over 1/2H and less than 1H. Also, the
period of the sampling enable signal may be 1H. The sampling unit
21 does not execute the sampling function during the time when the
sampling enable signal SEN is at the low voltage V2, and the values
of the sensing output signal Sout are sampled only during the time
when the sampling enable signal SEN is the high voltage V1.
Alternative embodiments include configurations wherein the
positions of the high voltage V1 and the low voltage V2 of the
sampling enable signal SEN may be exchanged with each other. In one
such alternative embodiment, the sampling unit 21 would execute the
sampling function only during the time when the sampling enable
signal SEN was at the low voltage.
[0104] The A/D converter 24 converts the sampled signal into a
digital data to generate contact information INF such as
coordinates of the contact position, and outputs the contact
information INF to an external device.
[0105] As described above, sampling is performed avoiding the
coupling noise Ns of the sensing output signal Sout, such that an
influence of the coupling noise may be removed from the contact
information.
[0106] Referring to FIG. 8, differently from the exemplary
embodiment of FIG. 7, the sampling enable signal SEN may be
generated in a signal generator 26 within the touch controller 20.
The signal generator 26 may receive the clock signal CKV or the
gate signal from the display panel device to generate the sampling
enable signal SEN as shown in FIG. 9, and may supply the sampling
enable signal SEN to the sampling unit 21.
[0107] Next, a coupling noise eliminating method of another
exemplary embodiment of a touch panel device according to the
present invention will be described with reference to FIG. 10 and
FIG. 11 as well as FIG. 1 to FIG. 6.
[0108] FIG. 10 is a block diagram of another exemplary embodiment
of a touch controller according to the present invention, and FIG.
11 is a waveform diagram of a gate signal, a noise-free sensing
output signal, and a sensing output signal according to the
exemplary embodiment of a touch controller shown in FIG. 10.
[0109] Referring to FIG. 10, a touch controller 20 of a touch panel
device according to an exemplary embodiment of the present
invention includes a synchronizing unit 28, a register 30, a
sampling unit 21 and an A/D converter 24.
[0110] The synchronizing unit 28 receives the clock signal CKV or
the gate signals Vg1, . . . , Vgk from the display panel device,
synchronizes them with the sensing output signal Sout, such that a
time period wherein the coupling noise is not present in the
sensing output signal Sout, that is, the sampling time, is
determined. To make the sampling time uniform for every period of
the sensing output signal Sout, the period Ts of the sensing output
signal Sout may be N times (N=1, 2, . . . , wherein N is a positive
integer) 1H. Accordingly, as shown in FIG. 11, the position of the
coupling noise Ns is uniform every period of the sensing output
signal Sout.
[0111] This determined sampling time as a sampling time information
Itime that is the information during the period Ts of the sensing
output signal Sout is stored in the register 30, and then is
provided to the sampling unit 21. The sampling time information
Itime includes a blocking period Bt corresponding to the coupling
noise Ns and a sampling period At corresponding to the portion of
the sensing output signal Sout where the coupling noise Ns is not
present. For example, the blocking period Bt may start 1/4H or less
before the coupling noise time and end 1/4H or less after the
coupling noise time. That is, the blocking period Bt may last 1/2H
or less around the point of the coupling noise, and the sampling
period At may last 1/2H or more avoiding the point of the coupling
noise.
[0112] The sampling unit 21 receives the sampling time information
Itime from the register 30 to execute the sampling using the
sampling time information Itime excluding the coupling noise Ns of
the sensing output signal Sout, and outputs the sampled result to
the A/D converter 24. As shown in FIG. 11, the sampling time
information Itime may correspond to the period Ts of the sensing
output signal Sout.
[0113] The A/D converter 24 converts the sampled signal into a
digital data to generate contact information INF such as
coordinates of the contact position and output the contact
information INF to an external device.
[0114] As described above, the sampling position of the sensing
output signal Sout is previously determined and is stored to the
register 30 of the touch controller 20 such that the influence by
the coupling noise may be easily removed from the contact
information INF.
[0115] Next, a coupling noise eliminating method of another
exemplary embodiment of a touch panel device according to the
present invention will be described with reference to FIG. 12 to
FIG. 16 as well as FIG. 1 to FIG. 6.
[0116] FIG. 12 is a block diagram of another exemplary embodiment
of a touch controller according to the present invention, and FIG.
13 is a waveform diagram of a sensing output signal, a reference
noise signal, and a coupling noise removed sensing output signal
according to the exemplary embodiment of a touch controller shown
in FIG. 12.
[0117] Referring to FIG. 12, an exemplary embodiment of a touch
controller 20 of a touch panel device according to the present
invention includes a noise removing unit 32, a sampling unit 21,
and an A/D converter 24.
[0118] The noise removing unit 32 receives the sensing output
signal Sout and a reference noise signal Nref from the touch panel
10 to remove the coupling noise Ns from the sensing output signal
Sout and to generate the noise-free sensing output signal Sout0.
The reference noise signal Nref is a signal including only the
coupling noise Ns of the sensing output signal Sout with reference
to the reference voltage such as 0V, as shown in FIG. 13. The noise
removing unit 32 subtracts the reference noise signal Nref from the
input sensing output signal Sout to remove the coupling noise from
the sensing output signal Sout, thereby generate the noise-free
sensing output signal Sout0.
[0119] The sampling unit 21 samples the noise-free sensing output
signal Sout0 and outputs it to the A/D converter 24.
[0120] The A/D converter 24 converts the sampled signal into
digital data to generate the contact information INF such as
coordinates of the contact position, and outputs the contact
information INF to an external device.
[0121] As described above, the influence of the coupling noise may
be easily removed from the contact information INF by subtracting
the reference noise signal Nref from the sensing output signal
Sout.
[0122] Next, an exemplary embodiment of a method for generating a
reference noise signal Nref according to the present invention will
be described with reference to FIG. 14.
[0123] FIG. 14 is a block diagram of an exemplary embodiment of the
touch panel device shown in FIG. 12.
[0124] Referring to FIG. 14, the exemplary embodiment of a touch
panel device according to the present invention includes a touch
panel 10 and a touch controller 20, and the touch panel 10 includes
a touch region 13 and a reference noise extracting region 14. As
illustrated in FIG. 14, the reference noise extracting region 14 is
disposed in a thin strip along a bottom portion of the touch panel
10, however the shape and location of the reference noise
extracting region 14 is not limited thereto.
[0125] Electrodes 16 for transmitting the sensing input signal Sin
or the sensing output signal Sout are formed in the touch region
13, and an additional electrode 17 that is separated from the
electrodes 16 of the touch region 13 is formed in the reference
noise extracting region 14. Both ends of the additional electrode
17 of the reference noise extracting region 14 are applied with the
reference voltage such as 0 V from the touch controller 20 through
a reference noise signal line 15. The output signal from the
additional electrode 17 of the reference noise extracting region
14, that is, the reference noise signal Nref, is influenced by the
coupling noise generated by the gate signal of the display panel
directly under the additional electrode 17, and such reference
noise signal is essentially equivalent to, e.g., it is the same as,
the coupling noise Ns included in the sensing output signal Sout
from the touch region 13.
[0126] Next, an exemplary embodiment of a method for generating a
reference noise signal Nref according to the present invention will
be described with reference to FIG. 15 and FIG. 16.
[0127] FIG. 15 is a block diagram of another exemplary embodiment
of the touch panel device, and FIG. 16 is a waveform diagram of a
sensing output signal according to the exemplary embodiment of a
touch panel device shown in FIG. 15.
[0128] Referring to FIG. 15, an exemplary embodiment of a touch
panel 10 according to the present invention includes a plurality of
y-axis electrodes Ey1, Ey2, Ey3, . . . , Eym that are substantially
parallel to each other and extended in the row direction, and a
plurality of x-axis electrodes Ex1, Ex2, Ex3, . . . , Exn that are
substantially parallel to each other and extended in the column
direction and insulated from and intersecting the y-axis electrodes
Ey1, Ey2, Ey3, . . . , Eym. In one exemplary embodiment, the y-axis
electrodes and the x-axis electrodes are disposed substantially
perpendicular to one another Exemplary embodiments include
configurations wherein the x-axis electrodes Ex1, Ex2, Ex3, . . . ,
Exn and the y-axis electrodes Ey1, Ey2, Ey3, . . . , Eym may be
made of a transparent conductive material such as indium tin oxide
("ITO"), indium zinc oxide ("IZO") and other materials with similar
characteristics. The x-axis electrodes Ex1, Ex2, Ex3, . . . , Exn
and the y-axis electrodes Ey1, Ey2, Ey3, . . . , Eym are
respectively connected to the touch controller 20 through the
signal lines thereby receiving the sensing input signal Sin and
outputting the sensing output signal Sout to the touch controller
20. This exemplary embodiment of a touch panel device may obtain
contact information of a multi-touch event even when several
positions are simultaneously touched.
[0129] As shown in FIG. 15, if an external object is contacted at a
touch point Pt (e.g., the intersection of the x-axis electrode Ex2
and the y-axis electrode Ey2) of the touch panel 10, as shown in
FIG. 16 sensing output signals Sout(x2) and Sout(y2) including a
touch period Ptp(x) and Ptp(y) including the information of the
touch position, and the coupling noise caused by the gate signal
are output from the x-axis electrode Ex2 and the y-axis electrode
Ey2 at the touch point Pt. However, output signals Sout(x1),
Sout(x3), . . . , Sout(xn), and Sout(y1), Sout(y3), . . . ,
Sout(ym) only include the coupling noise caused by the gate signal
with reference to the reference voltage such as 0V and are output
from the x-axis electrodes Ex1, Ex3, . . . , Exn and the y-axis
electrodes Ey1, Ey3, . . . , Eym except for the touch point Pt. The
output signals Sout(x1), Sout(x3), . . . , Sout(xn), and Sout(y1),
Sout(y3), . . . , Sout(ym), which include only the coupling noise
caused by the gate signal with reference to the reference voltage
such as 0V, may be used as the reference noise signal Nref as shown
in FIG. 13.
[0130] Next, an exemplary embodiment of a method for eliminating
the coupling noise of a touch panel device according to the present
invention will be described with reference to FIG. 17 to FIG. 19 as
well as FIG. 1 to FIG. 6.
[0131] FIG. 17 is a block diagram of another exemplary embodiment
of a touch panel device according to the present invention, FIG. 18
is a block diagram of a touch controller according to the exemplary
embodiment of a touch panel device shown in FIG. 17, and FIG. 19 is
a waveform diagram of a sensing output signal, a reversion sensing
output signal and a coupling noise removed sensing output signal
according to the exemplary embodiment of a touch panel device and
touch controller shown in FIG. 17 and FIG. 18.
[0132] Referring to FIG. 17, an exemplary embodiment of a touch
panel device according to the present invention includes a touch
panel 10 and a touch controller 20 connected thereto.
[0133] The touch controller 20 sequentially inputs an inversion
sensing input signal Sin' and the sensing input signal Sin to the
touch panel 10 and receives the sensing output signal Sout and an
inversion sensing output signal Sout' from the touch panel 10. The
inversion sensing input signal Sin' is a polarity-inverted signal
of the sensing input signal Sin, the inversion sensing output
signal Sout' is an output signal corresponding to the inversion
sensing input signal Sin', and, as has been previously described,
the sensing output signal Sout is the output signal corresponding
to the sensing input signal Sin.
[0134] The touch controller 20 processes the sensing output signal
Sout to generate contact information INF such as coordinates of the
contact position, and sends it to an external device (not shown).
The external device transmits the input image signal to the display
panel device based on the contact information INF.
[0135] Referring to FIG. 18, the touch controller 20 includes a
noise removing unit 32, a sampling unit 21 and an A/D converter
24.
[0136] The noise removing unit 32 receives the sensing output
signal Sout and the inversion sensing output signal Sout' from the
touch panel 10, removes the coupling noise Ns from the sensing
output signal Sout, and thereby generates a noise-free sensing
output signal Sout. Next, an exemplary embodiment of a method for
removing the coupling noise will be described with reference to
FIG. 19.
[0137] Referring to FIG. 19, the coupling noise Ns loaded in the
sensing output signal Sout and the inversion sensing output signal
Sout' have substantially the same phase and the same potential
values, and the remaining portions are substantially similar except
that they have the opposite polarity. Accordingly, as shown in FIG.
19, if the inversion sensing output signal Sout' is subtracted from
the sensing output signal Sout, and then the subtraction result is
divided by 2, i.e., the subtraction result is divided in half, the
coupling noises Ns are offset with each other such that the
noise-free sensing output signal Sout0 may be simply obtained.
[0138] The sampling unit 21 samples the noise-free sensing output
signal Sout0 and sends it to the A/D converter 24 and the A/D
converter 24 converts the sampled signal into the digital data to
generate the contact information INF such as the coordinates of the
contact position and sends it to an external device.
[0139] Next, an exemplary embodiment of a method for eliminating
the coupling noise of another exemplary embodiment of a touch panel
device according to the present invention will be described with
reference to FIG. 20 to FIG. 22 as well as FIG. 1 to FIG. 6.
[0140] FIG. 20 is a block diagram of an exemplary embodiment of a
touch controller according to the present invention, FIG. 21 is a
waveform diagram of the sensing output signal according to the
exemplary embodiment of a touch controller shown in FIG. 20, and
FIG. 22 is an enlarged view of a portion A of the sensing output
signal shown in FIG. 21.
[0141] Referring to FIG. 20, a touch controller 20 of an exemplary
embodiment of a touch panel device according to the present
invention includes a sampling unit 21, a filter 23 and an A/D
converter 24.
[0142] The sampling unit 21 receives the sensing output signal Sout
from the touch panel 10 for sampling, and sends it to the filter
23.
[0143] The filter 23 removes the data corresponding to the coupling
noise from the data of the sampled signals, and sends the result to
the A/D converter 24.
[0144] The A/D converter 24 converts the sampled signal from which
the coupling noise is removed into a digital data to generate
contact information INF such as the coordinates of the contact
position and sends the contact information INF to an external
device.
[0145] Next, an exemplary embodiment of a method for eliminating
the coupling noise through the filter 23 will be described with
reference to FIG. 21 and FIG. 22.
[0146] As shown in FIG. 21 and FIG. 22, the data at the sampling
positions a1, a2, . . . , a15 that are extracted to be converted
into digital data include the data Vb and Vc corresponding to the
coupling noise Ns as well as the normal data Va. The filter 23
compares the extracted data Va, Vb, and Vc with each other, and if
the data at the n-th position an (n=1, 2, . . . , 15) shows a
difference greater than a predetermined value in comparison with
the surrounding data, the data at the n-th position an (n=1, 2, . .
. , 15) is regarded as a coupling noise and is removed. In this
way, if a portion corresponding to the coupling noise Ns of the
sensing output signal Sout is sampled, the corresponding portion is
removed such that an influence of the coupling noise may be removed
from the contact information. In the present exemplary embodiment
illustrated in FIG. 22 there are 15 sampled positions, however the
present invention is not limited thereto.
[0147] As described above, according to the present exemplary
embodiment, when the touch panel 10 is attached to the display
panel 300 or is embedded inside the display panel 300, the coupling
noise by the gate signal may be easily removed such that an error
in the generation of contact information due to the coupling noise
i may be prevented. Also, the touch accuracy of a display device
requiring minute touch resolution may be improved.
[0148] In the several exemplary embodiments of the present
invention, the touch panel may be a touch panel of the various
kinds such as a resistive type, a capacitive type, an
electro-magnetic ("EM") type, or various other similar types of
touch panels. Also, various characteristics of the present
invention may be applied to the display device including the touch
panel of the various structures.
[0149] Further, in an exemplary embodiment of the present
invention, the gate signal of the display panel was described as an
example as the cause of the coupling noise of the sensing output
signal Sout; but the present invention is not limited thereto, and
the signal causing the coupling noise may be various signals
varying between a high voltage and a low voltage and may be
eliminated using devices and methods as described above.
[0150] While this invention has been described in connection with
what is presently considered to be practical exemplary embodiments,
it is to be understood that the invention is not limited to the
disclosed embodiments, but, on the contrary, is intended to cover
various modifications and equivalent arrangements included within
the spirit and scope of the appended claims.
* * * * *