U.S. patent application number 16/056486 was filed with the patent office on 2018-11-29 for touch display apparatus, driving circuit, and driving method.
This patent application is currently assigned to FOCALTECH ELECTRONICS, LTD.. The applicant listed for this patent is FOCALTECH ELECTRONICS, LTD.. Invention is credited to Xinxi JIANG, Junqiao LIU, Lianghua MO.
Application Number | 20180341365 16/056486 |
Document ID | / |
Family ID | 50360511 |
Filed Date | 2018-11-29 |
United States Patent
Application |
20180341365 |
Kind Code |
A1 |
MO; Lianghua ; et
al. |
November 29, 2018 |
TOUCH DISPLAY APPARATUS, DRIVING CIRCUIT, AND DRIVING METHOD
Abstract
A touch display apparatus, a corresponding driving circuit, and
a driving method are provided. The touch display apparatus includes
a driving circuit configured to, during the touch sensing stage,
provide a first signal to a common electrode for realizing touch
detection during the touch sensing stage, a second signal used to
control a thin film transistor of the touch display apparatus to be
switched off and is used to decrease charge and discharge capacity
of a capacitor formed by the common electrode and the gate line,
and a third signal used to decrease charge and discharge capacity
of a capacitor formed by the common electrode and a data line. The
third signal is used to control the data line to enter a floating
state during the touch sensing stage.
Inventors: |
MO; Lianghua; (Shenzhen,
CN) ; JIANG; Xinxi; (Shenzhen, CN) ; LIU;
Junqiao; (Shenzhen, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FOCALTECH ELECTRONICS, LTD. |
Grand Cayman |
|
KY |
|
|
Assignee: |
FOCALTECH ELECTRONICS, LTD.
Grand Cayman
KY
|
Family ID: |
50360511 |
Appl. No.: |
16/056486 |
Filed: |
August 6, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15108213 |
Jun 24, 2016 |
10073562 |
|
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PCT/CN2014/072080 |
Feb 14, 2014 |
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16056486 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 3/0416 20130101;
G06F 3/0412 20130101; G02F 1/13338 20130101; G06F 3/044 20130101;
G09G 3/3688 20130101; G09G 3/3677 20130101; G06F 3/04166 20190501;
G02F 1/13439 20130101; G09G 2310/0281 20130101; G09G 2310/08
20130101; G09G 2310/0248 20130101; G06F 3/0418 20130101; G06F
3/0443 20190501; G09G 3/3655 20130101 |
International
Class: |
G06F 3/041 20060101
G06F003/041; G09G 3/36 20060101 G09G003/36; G02F 1/1343 20060101
G02F001/1343; G02F 1/1333 20060101 G02F001/1333; G06F 3/044
20060101 G06F003/044 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 31, 2013 |
CN |
201310753359.1 |
Claims
1. A touch display apparatus for realizing touch sensing and
displaying, comprising: a driving circuit configured to provide a
first signal to a common electrode of the touch display apparatus
for realizing touch detection during the touch sensing stage,
wherein the driving circuit is further configured to provide a
second signal to a gate line of the touch display apparatus during
the touch sensing stage, wherein the second signal is used to
control a thin film transistor of the touch display apparatus to be
switched off and is used to decrease charge and discharge capacity
of a capacitor formed by the common electrode and the gate line;
and/or wherein the driving circuit is further configured to provide
a third signal during the touch sensing stage, the third signal is
used to decrease charge and discharge capacity of a capacitor
formed by the common electrode and a data line of the touch display
apparatus, and the third signal is used to control the data line to
enter a floating state during the touch sensing stage.
2. The touch display apparatus according to claim 1, wherein the
second signal is a pulse signal with a same frequency and a same
phase as the first signal, or the second signal is a pulse signal
with a same frequency, a same phase and a same amplitude as the
first signal.
3. The touch display apparatus according to claim 1, wherein the
driving circuit is coupled to the data lines via a switch, and the
third signal is used to control the switch to be switched off to
control the data line to enter the floating state.
4. The touch display apparatus according to claim 1, wherein the
driving circuit comprises: a common electrode driving unit
configured to generate a common voltage signal and the first
signal, wherein the common voltage signal is provided to the common
electrode during a display stage; a gate driving unit coupled to a
plurality of gate lines, wherein the gate driving unit is
configured to generate a driving signal, and is further configured
to generate the second signal, wherein the second signal has a same
frequency as the first signal, and the driving signal is provided
to the gate lines during the display stage; a data line driving
unit coupled to a plurality of data lines, and configured to
generate a display signal, wherein the display signal is provided
to the data lines during the display stage; and a timing control
unit coupled to the common electrode driving unit, the gate driving
unit and the data line driving unit, wherein the timing control
unit is configured to, during the display stage, control the gate
driving unit to provide the driving signal to the plurality of gate
lines sequentially, control the data line driving unit to provide
the display signal to the data line, and control the common
electrode driving unit to provide the common voltage signal to the
common electrode; and the timing control unit is further configured
to, during the touch sensing stage, control the common electrode
driving unit to provide the first signal to the common electrode
for realizing touch detection, and control the gate driving unit to
provide the second signal to the plurality of gate lines, wherein
the second signal has a same phase as the first signal.
5. The touch display apparatus according to claim 4, wherein the
driving circuit further comprises switches arranged between the
data line driving unit and the plurality of data lines, and the
data line driving unit is configured to provide a pixel voltage to
the data lines as a display signal in a case that the switches are
on; and the timing control unit is connected to the switches, the
timing control unit is configured to control the switches to be
switched on during the display stage to control the data line
driving unit to provide the pixel voltage to the data line, and the
timing control unit is further configured to control the switches
to be switched off during the touch sensing stage via the third
signal to control the data line to enter the floating state.
6. The touch display apparatus according to claim 1, wherein the
driving circuit comprises: a common electrode driving unit
configured to generate a common voltage signal and the first
signal, wherein the common voltage signal is provided to the common
electrode during a display stage; a gate driving unit coupled to a
plurality of gate lines, and configured to generate a driving
signal, wherein the driving signal is provided to the gate lines
during the display stage; a data line driving unit coupled to a
plurality of data lines, wherein the data line driving unit is
configured to generate a display signal and the third signal, the
display signal is provided to the data lines during the display
stage; and a timing control unit coupled to the common electrode
driving unit, the gate driving unit and the data line driving unit,
wherein the timing control unit is configured to, during the
display stage, control the gate driving unit to provide the driving
signal to the plurality of gate lines sequentially, control the
data line driving unit to provide the display signal to the data
line, and control the common electrode driving unit to provide the
common voltage signal to the common electrode; the timing control
unit is further configured to control the common electrode driving
unit to provide the first signal to the common electrode during the
touch sensing stage for realizing touch detection; and the timing
control unit is further configured to control the data lines to
enter the floating state via the third signal.
7. The touch display apparatus according to claim 6, wherein the
data line driving unit is coupled to the plurality of data lines
via switches, and the timing control unit is configured to control
the switches to be switched off via the third signal to control the
data lines to enter the floating state.
8. The touch display apparatus according to claim 1, wherein the
driving circuit is directly connected to the gate line; or the
driving circuit is coupled to the gate line in a capacitive
coupling manner.
9. A driving circuit for driving a touch display apparatus,
comprising: a first driving module configured to provide a first
signal to a common electrode of the touch display apparatus for
realizing touch detection during the touch sensing stage; and a
second driving module configured to provide a second signal to a
gate line of the touch display apparatus during the touch sensing
stage, wherein the second signal is used to control a thin film
transistor of the touch display apparatus to be switched off and is
used to decrease charge and discharge capacity of a capacitor
formed by the common electrode and the gate line; and/or a third
driving module configured to provide a third signal during the
touch sensing stage, wherein the third signal is used to decrease
charge and discharge capacity of a capacitor formed by the common
electrode and a data line of the touch display apparatus, and the
third signal is used to control the data line to enter a floating
state during the touch sensing stage.
10. The driving circuit according to claim 9, wherein the second
signal is a pulse signal with a same frequency and a same phase as
the first signal, or the second signal is a pulse signal with a
same frequency, a same phase and a same amplitude as the first
signal.
11. The driving circuit according to claim 9, wherein the third
driving module is coupled to the data line via a switch, and the
third signal is used to control the switch to be switched off to
control the data line to enter the floating state.
12. The driving circuit according to claim 9, wherein the driving
circuit comprises: a common electrode driving unit configured to
generate a common voltage signal and the first signal, wherein the
common voltage signal is provided to the common electrode during a
display stage; a gate driving unit coupled to a plurality of gate
lines, wherein the gate driving unit is configured to generate a
driving signal, and is further configured to generate the second
signal, wherein the second signal has a same frequency as the first
signal, and the driving signal is provided to the gate lines during
the display stage; a data line driving unit coupled to a plurality
of data lines, and configured to generate a display signal, wherein
the display signal is provided to the data lines during the display
stage; a timing control unit coupled to the common electrode
driving unit, the gate driving unit and the data line driving unit,
wherein the timing control unit is configured to, during the
display stage, control the gate driving unit to provide the driving
signal to the plurality of gate lines sequentially, control the
data line driving unit to provide the display signal to the data
line, control the common electrode driving unit to provide the
common voltage signal to the common electrode, and the timing
control unit is further configured to, during the touch sensing
stage, control the common electrode driving unit to provide the
first signal to the common electrode for realizing touch detection,
and control the gate driving unit to provide the second signal to
the plurality of gate lines, wherein the second signal has same
phase as the first signal.
13. The driving circuit according to claim 12, wherein the driving
circuit further comprises switches arranged between the data line
driving unit and the plurality of data lines, and the data line
driving unit is configured to provide a pixel voltage to the data
lines as a display signal in a case that the switches are on; and
the timing control unit is connected to the switches, the timing
control unit is configured to control the switches to be switched
on during the display stage to control the data line driving unit
to provide the pixel voltage to the data line; and the timing
control unit is further configured to control the switches to be
switched off during the touch sensing stage via the third signal to
control the data line to enter the floating state.
14. The driving circuit according to claim 9, comprising: a common
electrode driving unit configured to generate a common voltage
signal and the first signal, wherein the common voltage signal is
provided to the common electrode during a display stage; a gate
driving unit coupled to a plurality of gate lines, and configured
to generate a driving signal, wherein the driving signal is
provided to the gate lines during the display stage; a data line
driving unit coupled to a plurality of data lines, wherein the data
line driving unit is configured to generate a display signal and
the third signal, the display signal is provided to the data lines
during the display stage; and a timing control unit coupled to the
common electrode driving unit, the gate driving unit and the data
line driving unit, wherein the timing control unit is configured
to, during the display stage, control the gate driving unit to
provide the driving signal to the plurality of gate lines
sequentially, control the data line driving unit to provide the
display signal to the data line, and control the common electrode
driving unit to provide the common voltage signal to the common
electrode; the timing control unit is further configured to control
the common electrode driving unit to provide the first signal to
the common electrode during the touch sensing stage for realizing
touch detection, and the timing control unit is further configured
to control the data line to enter the floating state via the third
signal.
15. The driving circuit according to claim 14, wherein the data
line driving unit is coupled to the plurality of data lines via
switches, and the timing control unit is configured to control the
switches to be switched off via the third signal to control the
data lines to enter the floating state.
16. The driving circuit according to claim 9, wherein the first
driving module is directly connected to the gate line; or the first
driving module is coupled to the gate line in a capacitive coupling
manner.
17. A driving method for driving a touch display apparatus,
comprising: providing a driving signal to a plurality of gate lines
of the touch display apparatus sequentially, providing a display
signal to a data line of the touch display apparatus, and providing
a common voltage signal to a plurality of electrode units of a
common electrode of the touch display apparatus, during a display
stage; providing a first signal to the common electrode for
realizing touch detection during the touch sensing stage; and
providing a second signal to the gate lines in the process of
providing the first signal to the common electrode, wherein the
second signal is used to control a thin film transistor of the
touch display apparatus to be switched off and is used to decrease
charge and discharge capacity of a capacitor formed by the common
electrode and the gate lines; and/or providing a third signal in
the process of providing the first signal to the common electrode,
wherein the third signal is used to decrease charge and discharge
capacity of a capacitor formed by the common electrode and the data
line, and controlling the data line to enter a floating state via
the third signal.
18. The driving method according to claim 17, wherein the second
signal is a pulse signal with a same frequency and a same phase as
the first signal, or the second signal is a pulse signal with a
same frequency, a same phase and a same amplitude as the first
signal.
19. The driving method according to claim 17, wherein a switch is
connected to the data line, and the controlling the data line to
enter a floating state via the third signal comprises: controlling
the switch to be switched off via the third signal to control the
data line to enter the floating state.
Description
[0001] The present application is a continuation application of
U.S. Ser. No. 15/108213, which is the national phase of
International Application No. PCT/CN2014/072080, titled "TOUCH
DISPLAY APPARATUS, DRIVING CIRCUIT, AND DRIVING METHOD", filed on
Feb. 14, 2014, which claims the priority to Chinese Patent
Application No. 201310753359.1, titled "TOUCH DISPLAY APPARATUS,
DRIVING CIRCUIT, AND DRIVING METHOD", filed with the Chinese State
Intellectual Property Office on Dec. 31, 2013, all of which are
incorporated herein by reference in entirety.
FIELD
[0002] The disclosure relates to the field of touch technology, and
in particular to a touch display apparatus, a driving circuit and a
driving method.
BACKGROUND
[0003] Currently, a touch panel, as input medium, is a most simple,
convenient and natural means for human-computer interaction.
[0004] Reference is made to FIG. 1, a liquid crystal display
apparatus with an in-cell touch panel (In-cell touch panel)
according to the conventional technology is shown. The liquid
crystal display apparatus includes, from bottom to top, a thin film
transistor (TFT, Thin Film Transistor) substrate 1, a liquid
crystal layer (Liquid Crystal) 2 and a color filter (CF, Color
Filter) substrate 3. The TFT substrate includes a first glass
substrate 11, and thin film transistors 12 arranged on the first
glass substrate 11. The CF substrate includes, from bottom to top,
a common electrode 31, a color filter 32, a touch screen 33 and a
second glass substrate 34. The touch screen 33 in FIG. 1 may be a
self-capacitive touch screen. The self-capacitive touch screen
detects capacitance formed by a driving electrode or a sensing
electrode and the ground, and position detection is performed based
on change in the capacitance caused by a finger touching the touch
panel.
[0005] During the display of the liquid crystal display apparatus,
a liquid crystal display driving circuit switches on the thin film
transistors 12 row by row via a gate line, a data line provides a
pixel voltage to a pixel electrode 35 of each sub-pixel, and the
pixel voltage is provided to the common electrode 31. Reference is
made to FIG. 2, an equivalent circuit diagram of a sub-pixel unit
in the liquid crystal display apparatus shown in FIG. 1 is shown.
An equivalent capacitor Clc is formed by the pixel electrode 35 and
the common electrode 31. An electric field in the equivalent
capacitor Clc may pass through liquid crystal molecules in the
liquid crystal layer 2. The magnitude of the electric field
determines an angle of rotation of the liquid crystal molecule,
which in turn determines the strength of the light passing through
this sub-pixel in a specific direction.
[0006] With increased requirement on lightness and thinness for the
touch panel, the common electrode is reused as a detection
electrode for self-capacitance touch detection. As shown in FIG. 3,
a schematic diagram of a common electrode is shown. The common
electrode includes multiple block electrodes 36 in four rows and
four columns. Each of the block electrodes 36 is connected to a
driving chip 37 via a connecting line. The driving chip 37 drives
the multiple block electrodes 36 in a time-sharing manner. That is,
the driving chip 37 drives the common electrode to a potential
required for display during a display stage, and provides a touch
detection signal to the common electrode during a touch detecting
stage.
[0007] However, the common electrode forms multiple parasitic
capacitors during the touch detecting stage, which affects the
accuracy of the touch detection. Reference is made to FIG. 4, an
equivalent circuit diagram of the sub-pixel unit of the touch
display apparatus of the common electrode as shown in FIG. 3 is
shown. The common electrode is used as a touch detection electrode.
Thus, a parasitic capacitor Cmg is formed between the common
electrode and a gate line, a parasitic capacitor Cms is formed
between the common electrode and a data line, and a parasitic
capacitor Cs is formed between the common electrode and an outline
of a screen body. The parasitic capacitors would interfere with the
touch detection.
SUMMARY
[0008] The problem to be solved by the present disclosure is to
provide a touch display apparatus, a driving circuit and a driving
method for reducing the interference to the touch detection from a
parasitic capacitor and improve the accuracy of the touch
detection.
[0009] To solve the above problem, it is provided a touch display
apparatus for realizing touch sensing and displaying according to
the present disclosure. The touch display apparatus includes: a
first substrate; a second substrate arranged opposite to the first
substrate, where gate lines, data lines and thin film transistors
are arranged on a surface of the second substrate facing towards
the first substrate; a liquid crystal layer arranged between the
first substrate and the second substrate; a common electrode
arranged between the first substrate and the second substrate and
used as a touch sensing electrode during a touch sensing stage; and
a driving circuit configured to provide a first signal to the
common electrode for realizing touch detection during the touch
sensing stage, where the driving circuit is further configured to
provide a second signal to the gate line during the touch sensing
stage, where the second signal is used to control the thin film
transistor to be switched off and is used to decrease charge and
discharge capacity of a capacitor formed by the common electrode
and the gate line; and/or the driving circuit is further configured
to provide a third signal to the data line during the touch sensing
stage, where the third signal is used to decrease charge and
discharge capacity of a capacitor formed by the common electrode
and the data line.
[0010] Optionally, the second signal may be a pulse signal with a
same frequency and a same phase as the first signal.
[0011] Optionally, the second signal may be a pulse signal with a
same frequency, a same phase and a same amplitude as the first
signal.
[0012] Optionally, the third signal may be a pulse signal with a
same frequency and a same phase as the first signal.
[0013] Optionally, the third signal may be a pulse signal with a
same frequency, a same phase and a same amplitude as the first
signal. Optionally, the third signal may be a signal used to
control the data line to enter a floating state.
[0014] Optionally, the first signal, the second signal or the third
signal may be a square signal, a sine wave signal or a stair-step
signal.
[0015] Optionally, the driving circuit may be further configured
to: provide a driving signal to the gate line, provide a display
signal to the data line, and provide a common voltage signal to the
common electrode, during a display stage.
[0016] Optionally, the driving circuit may include: a common
electrode driving unit configured to generate the common voltage
signal and a first pulse signal; a gate driving unit connected to
multiple gate lines, where the gate driving unit may be configured
to generate the driving signal, and is further configured to
generate a second pulse signal with a same frequency as the first
pulse signal; a data line driving unit connected to multiple data
lines, and configured to generate the display signal; and a timing
control unit connected to the common electrode driving unit, the
gate driving unit and the data line driving unit, where the timing
control unit may be configured to, during the display stage,
control the gate driving unit to provide the driving signal to the
multiple gate lines sequentially, control the data line driving
unit to provide the display signal to the data line, and control
the common electrode driving unit to provide the common voltage
signal to the common electrode; and the timing control unit may be
further configured to, during the touch sensing stage, control the
common electrode driving unit to provide the first pulse signal to
the common electrode for realizing touch detection, and control the
gate driving unit to provide the second pulse signal with the same
phase as the first pulse signal to the multiple gate lines.
[0017] Optionally, the data line driving unit may be further
configured to generate a third pulse signal with a same frequency
as the first pulse signal; and the timing control unit may be
further configured to control the data line driving unit to provide
the third pulse signal with the same phase as the first pulse
signal to the multiple data lines during the touch sensing
stage.
[0018] Optionally, the driving circuit may further include switches
arranged between the data line driving unit and the multiple data
lines, and the data line driving unit may be configured to provide
a pixel voltage to the data line as a display signal in a case that
the switch is on; and the timing control unit may be connected to
the switch, the timing control unit may be configured to control
the switch to be switched on during the display stage to control
the data line driving unit to provide the pixel voltage to the data
line, and the timing control unit may be further configured to
control the switch to be switched off during the touch sensing
stage to control the data line to enter a floating state.
[0019] Optionally, the driving circuit may include: a common
electrode driving unit configured to generate the common voltage
signal and the first pulse signal; a gate driving unit connected to
multiple gate lines, and configured to generate the driving signal;
a data line driving unit connected to multiple data lines, where
the data line driving unit may be configured to generate a display
signal, and may be further configured to generate a third pulse
signal with a same frequency as the first pulse signal; or a data
line driving unit being coupled to the multiple data lines via a
switch; and a timing control unit connected to the common electrode
driving unit, the gate driving unit and the data line driving unit,
where the timing control unit may be configured to, during the
display stage, control the gate driving unit to provide the driving
signal to the multiple gate lines sequentially, control the data
line driving unit to provide the display signal to the data line,
and control the common electrode driving unit to provide the common
voltage signal to the common electrode; and the timing control unit
may be further configured to, during the touch sensing stage,
control the common electrode driving unit to provide the first
pulse signal to the common electrode for realizing touch detection,
and control the data line driving unit to provide the third pulse
signal with the same phase as the first pulse signal to the
multiple data lines or control the switch to be switched off to
control the data line to enter a floating state.
[0020] Optionally, the driving circuit may be directly connected to
the gate line.
[0021] Optionally, the driving circuit may be connected to the gate
line in a capacitive coupling manner.
[0022] Accordingly, it is further provided a driving circuit for
driving a touch display apparatus according to the present
disclosure. The touch display apparatus includes: a first
substrate; a second substrate arranged opposite to the first
substrate, where gate lines, data lines and thin film transistors
are arranged on a surface of the second substrate facing towards
the first substrate; a liquid crystal layer arranged between the
first substrate and the second substrate; and a common electrode
arranged between the first substrate and the second substrate and
used as a touch sensing electrode during a touch sensing stage. The
driving circuit includes: a first driving module configured to
provide a first signal to the common electrode for realizing touch
detection during the touch sensing stage; a second driving module
configured to provide a second signal to the gate line during the
touch sensing stage, where the second signal is used to control the
thin film transistor to be switched off and is used to decrease
charge and discharge capacity of a capacitor formed by the common
electrode and the gate line; and/or a third driving module
configured to provide a third signal to the data line during the
touch sensing stage, where the third signal is used to decrease
charge and discharge capacity of a capacitor formed by the common
electrode and the data line.
[0023] Optionally, the second signal may be a pulse signal with a
same frequency and a same phase as the first signal.
[0024] Optionally, the second signal may be a pulse signal with a
same frequency, a same phase and a same amplitude as the first
signal.
[0025] Optionally, the third signal may be a pulse signal with a
same frequency and a same phase as the first signal.
[0026] Optionally, the third signal may be a pulse signal with a
same frequency, a same phase and a same amplitude as the first
signal.
[0027] Optionally, the third signal may be a signal used to control
the data line to enter a floating state.
[0028] Optionally, the first signal, the second signal or the third
signal may be a square signal, a sine wave signal or a stair-step
signal.
[0029] Optionally, the first driving module may be further
configured to provide a common voltage signal to the common
electrode during a display stage, the second driving module may be
further configured to provide a driving signal to the gate line
during the display stage, and the third driving module may be
further configured to provide a display signal to the data line
during the display stage.
[0030] Optionally, the driving circuit may include: a common
electrode driving unit configured to generate the common voltage
signal and a first pulse signal; a gate driving unit connected to
multiple gate lines, where the gate driving unit may be configured
to generate the driving signal, and may be further configured to
generate a second pulse signal with a same frequency as the first
pulse signal; a data line driving unit connected to multiple data
lines, and configured to generate the display signal; a timing
control unit connected to the common electrode driving unit, the
gate driving unit and the data line driving unit, where the timing
control unit may be configured to, during the display stage,
control the gate driving unit to provide the driving signal to the
multiple gate lines sequentially, control the data line driving
unit to provide the display signal to the data line, control the
common electrode driving unit to provide the common voltage signal
to the common electrode, and the timing control unit may be further
configured to, during the touch sensing stage, control the common
electrode driving unit to provide the first pulse signal to the
common electrode for realizing touch detection, and control the
gate driving unit to provide the second pulse signal with the same
phase as the first pulse signal to the multiple gate lines.
[0031] Optionally, the data line driving unit may be further
configured to generate a third pulse signal with a same frequency
as the first pulse signal; and the timing control unit may be
further configured to control the data line driving unit to provide
the third pulse signal with the same phase as the first pulse
signal to the multiple data lines during the touch sensing
stage.
[0032] Optionally, the driving circuit may further include switches
arranged between the data line driving unit and the multiple data
lines, and the data line driving unit may be configured to provide
a pixel voltage to the data line as a display signal in a case that
the switch is on; and the timing control unit may be connected to
the switch, the timing control unit may be configured to control
the switch to be switched on during the display stage to control
the data line driving unit to provide the pixel voltage to the data
line; and the timing control unit may be further configured to
control the switch to be switched off during the touch sensing
stage to control the data line to enter a floating state.
[0033] Optionally, the driving circuit may include: a common
electrode driving unit configured to generate the common voltage
signal and the first pulse signal; a gate driving unit connected to
multiple gate lines, and configured to generate the driving signal;
a data line driving unit connected to multiple data lines, where
the data line driving unit may be configured to generate a display
signal, and may be further configured to generate a third pulse
signal with a same frequency as the first pulse signal; or a data
line driving unit connected to the multiple data lines via a
switch; and a timing control unit connected to the common electrode
driving unit, the gate driving unit and the data line driving unit,
where the timing control unit may be configured to, during the
display stage, control the gate driving unit to provide the driving
signal to the multiple gate lines sequentially, control the data
line driving unit to provide the display signal to the data line,
and control the common electrode driving unit to provide the common
voltage signal to the common electrode, and the timing control unit
may be further configured to, during the touch sensing stage,
control the common electrode driving unit to provide the first
pulse signal to the common electrode for realizing touch detection,
and control the data line driving unit to provide the third pulse
signal with the same phase as the first pulse signal to the
multiple data lines or control the switch to be switched off to
control the data line to enter a floating state.
[0034] Optionally, the first driving module may be directly
connected to the gate line.
[0035] Optionally, the first driving module may be connected to the
gate line in a capacitive coupling manner.
[0036] Accordingly, it is provided a driving method for driving a
touch display apparatus according to the present disclosure. The
touch display apparatus includes: a first substrate; a second
substrate arranged opposite to the first substrate, where gate
lines, data lines and thin film transistors are arranged on a
surface of the second substrate facing towards the first substrate;
a liquid crystal layer arranged between the first substrate and the
second substrate; and a common electrode arranged between the first
substrate and the second substrate and used as a touch sensing
electrode during a touch sensing stage. The driving method
includes: providing a driving signal to the multiple gate lines
sequentially, providing a display signal to the data line, and
providing a common voltage signal to multiple electrode units of
the common electrode, during a display stage; and providing a first
signal to the common electrode for realizing touch detection during
the touch sensing stage; providing a second signal to the gate line
in the process of providing the first signal to the common
electrode, where the second signal is used to control the thin film
transistor to be switched off and is used to decrease charge and
discharge capacity of a capacitor formed by the common electrode
and the gate line; and/or providing a third signal in the process
of providing the first signal to the common electrode, where the
third signal is used to decrease charge and discharge capacity of a
capacitor formed by the common electrode and the data line. The
second signal may be a pulse signal with a same frequency and a
same phase as the first signal.
[0037] Optionally, the second signal is a pulse signal with a same
frequency, a same phase and a same amplitude as the first
signal.
[0038] Optionally, the third signal may be a pulse signal with a
same frequency and a same phase as the first signal.
[0039] Optionally, the third signal may be a pulse signal with a
same frequency, a same phase and a same amplitude as the first
signal.
[0040] Optionally, the third signal may be a signal used to control
the data line to enter a floating state.
[0041] Optionally, the first signal, the second signal or the third
signal may be a square signal, a sine wave signal or a stair-step
signal.
[0042] Compared with the conventional technology, the technical
solution according to the present disclosure has the following
advantages:
[0043] with the driving circuit of the touch display apparatus
according to the present disclosure, during the touch sensing
stage, the first signal is provided to the common electrode, the
second signal is provided to the gate line and/or the third signal
is provided, thus charge and discharge capacity of a parasitic
capacitor formed by the common electrode and/or the gate line is
decreased. Interference of the parasitic capacitor to the touch
detection is reduced by decreasing the charge and discharge
capacity of the parasitic capacitor, thus the accuracy of touch
detection is improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] FIG. 1 is a schematic diagram of a liquid crystal display
apparatus with an in-cell touch panel according to the conventional
technology;
[0045] FIG. 2 is an equivalent circuit diagram of a sub-pixel unit
as shown in FIG. 1;
[0046] FIG. 3 is a schematic diagram of a common electrode having a
function of self-capacitive touch detection according to the
conventional technology;
[0047] FIG. 4 is an equivalent circuit diagram of a sub-pixel unit
of a touch display apparatus in which a conventional cot electrode
is reused as a touch electrode according to the conventional
technology;
[0048] FIG. 5 is a schematic diagram of a touch display apparatus
according to an embodiment of the present disclosure;
[0049] FIG. 6 is a schematic diagram of a driving signal of the
touch display apparatus shown in FIG. 5;
[0050] FIG. 7 is a schematic diagram of a driving circuit shower
FIG. 5 according to an embodiment;
[0051] FIG. 8 is a schematic is diagram of a gate driving unit
shown in FIG. 5 according to an embodiment;
[0052] FIG. 9 is a schematic diagram of a common electrode driving
unit shown in FIG. 5 according to an embodiment;
[0053] FIG. 10 is a schematic diagram of a data line driving unit
shown in FIG. 5 according to an embodiment; and
[0054] FIG. 11 is a schematic diagram of a touch display apparatus
according to another embodiment of the present disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS
[0055] To make the above features and advantages of the disclosure
more apparent and easier to be understood, specific embodiments of
the disclosure are illustrated in detail hereinafter in conjunction
with the drawings.
[0056] To solve the problem mentioned in the background, it is
provided a touch display apparatus according to the present
disclosure. Reference is made to FIG. 5, a schematic diagram of a
touch display apparatus according to an embodiment of the present
disclosure is shown. The touch display apparatus includes a first
substrate (not shown), a second substrate 111, a liquid crystal
layer, a common electrode 105 and a driving circuit 100.
[0057] The first substrate is used as a glass substrate at a side
of a color filter (Color Filter, CF).
[0058] The second substrate 111 is used as a glass substrate at a
side of a thin film transistor (Thin Film Transistor, TFT). The
second substrate 111 is arranged opposite to the first
substrate.
[0059] Multiple gate lines G.sub.1, G.sub.2 . . . G.sub.M, multiple
data lines S.sub.1, S.sub.2 . . . S.sub.N and thin film transistors
104 are arranged on a surface of the second substrate 111 facing
towards the first substrate. A drain of the thin film transistor
106 is connected to a pixel electrode (not shown), The multiple
gate lines G.sub.1, G.sub.2 . . . G.sub.M are electrically
connected to gates of the thin film transistors 104, and configured
to provide driving signals to the gates of the thin film
transistors 104. The multiple data lines S.sub.1, S.sub.2 . . .
S.sub.N are connected to sources of the thin film transistors 104,
and are configured to provide pixel voltages to the sources of the
thin film transistors 106.
[0060] The liquid crystal layer (not shown) is arranged between the
first substrate and the second substrate 111.
[0061] The common electrode 105 is arranged between the first
substrate and the second substrate 111. The common electrode 105 is
used as a touch sensing electrode during a touch sensing stage, and
is provided with a common voltage (VCOM) during a display stage.
Specifically, the common electrode 105 may include multiple
electrode units arranged in a matrix, and the multiple electrode
units are detection electrodes for realizing self-capacitive
detection in the touch sensing.
[0062] The driving circuit 100 is configured to provide a first
signal to the common electrode 105 for realizing touch detection
during the touch sensing stage. The driving circuit 100 is further
configured to provide a second signal to the gate lines G.sub.1,
G.sub.2 . . . G.sub.M during the touch sensing stage. The second
signal is used to control the thin film transistor to be switched
off and is used to decrease charge and discharge capacity of a
capacitor formed by the common electrode and the gate line. And/or,
the driving circuit 100 is further configured to provide a third
signal during the touch sensing stage. The third signal is used to
decrease charge and discharge capacity of a capacitor formed by the
common electrode and the data line.
[0063] It should be noted that, to decrease the charge and
discharge capacity of the capacitor formed by the common electrode
105 and the gate line (the data line) herein refers to: to decrease
the charge and discharge capacity as compared with that of a
capacitor in a case that no second signal (no third signal).
[0064] With the touch display apparatus according to the
embodiment, the first signal provided to the common electrode and
the second signal (the third signal) by the driving circuit can
decrease the charge and discharge capacity of the parasitic
capacitor formed by the common electrode and the gate line (the
data line), thus interference of the parasitic capacitor to the
touch detection is reduced, and accuracy of the touch detection is
improved.
[0065] Next, a principle of improving the accuracy of the touch
detection by the touch display apparatus according to the
embodiment shown in FIG. 5 is explained in conjunction with a
driving signal shown in FIG. 6.
[0066] As shown in FIG. 5, the driving circuit 100 in the
embodiment includes a common electrode driving unit 103, a gate
driving unit 101, a data line driving unit 102 and a timing control
unit (not shown).
[0067] The common electrode driving unit 103 is connected to the
common electrode 105, and is configured to generate the common
voltage signal VCOM and a first pulse signal 201 which is the first
signal. The first pulse signal 201 here is a square signal with a
low level of 0V and a high level of 2V The first pulse signal 201
is a detection signal provided to the common electrode used as the
touch sensing electrode for realizing touch detection.
[0068] The gate driving unit 101 is connected to multiple gate
lines G.sub.1, G.sub.2 . . . G.sub.M and is configured to generate
a second pulse signal 202. The gate driving unit 101 may be
directly connected to the gate lines G.sub.1, G.sub.2 . . .
G.sub.M, or may be connected to the gate lines G.sub.1, G.sub.2 . .
. G.sub.M in a capacitive coupling manner.
[0069] The second pulse signal 202 is the second signal, and the
second pulse signal 202 here is a square signal with a low level of
-12V and a high level of -10V, The second pulse signal 202 is a
pulse signal with a same frequency and a same amplitude (which is
2V) as the first pulse signal 201. The high level of the second
pulse signal 202 is much smaller than a threshold voltage of the
thin film transistor 104, so that the thin film transistor 104 is
switched off, thereby not affecting a signal provided to a liquid
crystal box during the touch sensing stage, and realizing a normal
display function of the touch display apparatus.
[0070] The data line driving unit 102 is connected to multiple data
lines S.sub.1, S.sub.2 . . . S.sub.N and is configured to generate
a third pulse signal 203 which is the third signal. The third pulse
signal 203 here is a square signal with a low level of 0V and a
high level of 2V The third pulse signal 203 is a pulse signal with
a same frequency and a same amplitude (which is 2V) as the first
pulse signal 201.
[0071] The timing control unit is connected to the common electrode
driving unit 103, the gate driving unit 101 and the data line
driving unit 102, and configured to, during the touch sensing
stage, control the common electrode driving unit 201 to provide the
first pulse signal to the common electrode 105 for realizing touch
detection, control the gate driving unit 101 to provide the second
pulse signal 202 with the same phase as the first pulse signal 201
to the multiple gate lines G.sub.1, G.sub.2 . . . G.sub.M, and
control the data line driving unit 102 to provide the third pulse
signal 230 with a same phase as the first pulse signal 201 to the
multiple data lines S.sub.1, S.sub.2 . . . S.sub.N.
[0072] In the driving circuit 100 of the touch display apparatus
according to the embodiment, the second pulse signal 202 with a
same frequency, a same phase and a same amplitude as the first
pulse signal 201 is provided to multiple gate lines G.sub.1,
G.sub.2 . . . G.sub.M by the gate driving unit 101 during the touch
sensing stage. Thus, even a capacitor is formed by the common
electrode 105 and the gate lines G.sub.1, G.sub.2 . . . G.sub.M,
the capacitor is not charged and discharged, since signals with
same frequency, a same phase and a same amplitude are provided to
two electrode plates formed by the common electrode 105 and the
gate lines G.sub.1, G.sub.2 . . . G.sub.M, that is, voltages of
same magnitude are provided to the two electrode plates of the
capacitor at any time, Hence, charge and discharge capacity of the
capacitor formed by the common electrode 105 and the gate lines
G.sub.1, G.sub.2 . . . G.sub.M is zero. Compared with a case that
the second pulse signal 202 is not provided to the gate lines
G.sub.1, G.sub.2 . . . G.sub.M, the charge and discharge capacity
is decreased up to zero. That is, the capacitor formed by the
common electrode 105 and the gate lines G.sub.1, G.sub.2 . . .
G.sub.M does not interfere with touch detection in a practical
circuit, and thus the accuracy of the touch detection is
improved.
[0073] In the driving circuit 100 of the touch display apparatus
according to the embodiment, the third pulse signal 203 with a same
frequency, a same phase and a same amplitude as the first pulse
signal 201 is provided to multiple data lines S.sub.1, S.sub.2 . .
. S.sub.N by the data line driving unit 102 during the touch
sensing stage. Thus, even a capacitor is formed by the common
electrode 105 and the data lines S.sub.1, S.sub.2 . . . S.sub.N,
the capacitor is not charged and discharged, since signals with
same frequency, a same phase and a same amplitude are provided to
two electrode plates formed by the common electrode 105 and the
data lines S.sub.1, S.sub.2 . . . S.sub.N, that is, voltages of
same magnitude are provided to the two electrode plates of the
capacitor at any time. Hence, charge and discharge capacity of the
capacitor formed by the common electrode 105 and the data lines
S.sub.1, S.sub.2 . . . S.sub.N is zero. Compared with a case that
the third pulse signal 203 is not provided to the data lines
S.sub.1, S.sub.2 . . . S.sub.N, the charge and discharge capacity
is decreased up to zero. That is, the capacitor formed by the
common electrode 105 and the data lines S.sub.1, S.sub.2 . . .
S.sub.N does not interfere with touch detection in a practical
circuit, and thus the accuracy of the touch detection is
improved.
[0074] It should also be noted that, the second pulse signal 202
and the third pulse signal 203 each have a same frequency, a same
phase and a same amplitude as the first pulse signal 201, so that
the capacitor formed by the common electrode and the gate lines
(the data lines) is not charged and discharged, which are not
limited thereto in the present disclosure, as long as the second
pulse signal 202 and the third pulse signal 203 each have a same
frequency and a same phase as the first pulse signal 201. Even
magnitudes of voltage provided to two electrode plates of the
capacitor are different at any time, a potential difference between
the electrode plates of the capacitor is decreased compared with a
case that no signal is provided to the gate lines, since signals of
two electrode plates have same frequency and a same phase. Thus,
the charge and discharge capacity of the capacitor formed by the
common electrode 105 and the gate lines G.sub.1, G.sub.2 . . .
G.sub.M (the data lines S.sub.1, S.sub.2 . . . S.sub.N) is
reduced.
[0075] It should be further noted that, the first signal, the
second signal and the third signal in an embodiment each are pulse
signals, which is not limited in the present disclosure, as long as
the signal is a signal provided to the common electrode 105, the
gate lines G.sub.1, G.sub.2 . . . G.sub.M and the data lines
S.sub.1, S.sub.2 . . . S.sub.N so to decrease the charge and
discharge capacity of the capacitor.
[0076] It should be further noted that, the first signal, the
second signal and the third signal in an embodiment each are square
signals, which is not limited in the present disclosure. The first
signal, the second signal and the third signal in another
embodiment may be sine wave signals or stair-step signals.
[0077] The driving circuit 100 of the touch display apparatus in
the embodiment can reduce an effect of the parasitic capacitor
between the common electrode 105 and the gate lines G.sub.1,
G.sub.2 . . . G.sub.M, and can reduce an effect of the parasitic
capacitor between the common electrode 105 and the data lines
S.sub.1, S.sub.2 . . . S.sub.N, which is not limited in the present
disclosure. In a touch display apparatus according to another
embodiment, only the gate driving unit 101 may be arranged, for
reducing interference of the parasitic capacitor between the common
electrode 105 and the gate lines G.sub.1, G.sub.2 . . . G.sub.M to
the touch detection. In the embodiment in which only the gate
driving unit 101 is arranged, the timing control unit only controls
the gate driving unit 101 to provide the second pulse signal 202
with a same phase as the first pulse signal 201 to the multiple
gate lines G.sub.1, G.sub.2 . . . G.sub.M.
[0078] Alternatively, in a touch display apparatus according to
another embodiment, only the data line driving unit 102 may be
arranged, for reducing interference of the parasitic capacitor
between the common electrode 105 and the data lines S.sub.1,
S.sub.2 . . . S.sub.N to the touch detection. In the embodiment in
which only the data line driving unit 102 is arranged, the timing
control unit only controls the data line driving unit 102 to
provide the third pulse signal 203 with a same phase as the first
pulse signal 201 to the multiple data lines S.sub.1, S.sub.2 . . .
S.sub.N.
[0079] Reference is made to FIG. 5 and FIG. 6 continuously, the
driving circuit 100 of the touch display apparatus according to the
embodiment serves to perform both driving display and driving touch
detection. A circuit part of driving display and a circuit part of
driving touch detection together are integrated into the driving
circuit 100.
[0080] Specifically, the driving circuit 100 is further configured
to provide a driving signal to the gate lines G.sub.1, G.sub.2 . .
. G.sub.M, provide a display signal to the data lines S.sub.1,
S.sub.2 . . . S.sub.N, and provide a common voltage signal to the
common electrode 105, during a display stage, which is not limited
in the present disclosure. In another embodiment, the driving
circuit may only function to perform the driving touch detection,
as long as the driving circuit can reduce the interference of the
parasitic capacitor during the touch sensing stage.
[0081] Specifically, the driving circuit 100 includes a total
timing controller (not shown) and is configured to drive to the
display stage and the touch sensing stage in a time-sharing manner.
The driving circuit 100 during the touch sensing stage is not
described herein, and reference may be made to the above
description. In the following, an operation of the driving circuit
100 during the display stage is introduced in detail.
[0082] As shown in FIG. 6, the gate driving unit 101 of the driving
circuit 100 is further configured to generate the driving signal.
Specifically, the driving circuit herein generates timing puke
signals driving the gate lines G.sub.1, G.sub.2 . . . G.sub.M
sequentially, and the pulse signal is a pulse signal with a high
level of 15V and a low level of 0V.
[0083] The data line driving unit 102 is further configured to
generate a display signal D.
[0084] The common electrode driving unit 103 is further configured
to generate a common voltage signal VCOM.
[0085] The timing control unit is connected to the common electrode
driving unit 103, the gate driving unit 101 and the data line
driving unit 102. The timing control unit is configured to, during
the display stage, control the gate driving unit 101 to provide a
driving signal to multiple gate lines G.sub.1, G.sub.2 . . .
G.sub.M sequentially, control the data line driving unit 102 to
provide the display signal D to the data lines S.sub.1, S.sub.2 . .
. S.sub.N, and control the common electrode driving unit 103 to
provide the common voltage signal VCOM to the common electrode 105.
The timing control unit is further configured to, during the touch
sensing stage, control the common electrode driving unit 103 to
provide the first pulse signal 201 to the common electrode 105 for
realizing touch detection, and control the gate driving unit 101 to
provide the second pulse signal 202 with a same phase as the first
pulse signal 201 to the multiple gate lines G.sub.1, G.sub.2 . . .
G.sub.M. The timing control unit is further configured to control
the data line driving unit 102 to provide the third pulse signal
202 with a same phase as the first pulse signal to multiple data
lines S.sub.1, S.sub.2 . . . S.sub.N during the touch sensing
stage.
[0086] In the following, the driving circuit 100 is further
explained in conjunction with a specific circuit.
[0087] Reference is made to FIG. 7, a schematic diagram of a
driving circuit shown in FIG. 5 according to an embodiment is
shown. The driving circuit 100 in the embodiment further includes
an on-screen gate circuit 106 arranged on a screen (a region of a
dashed box shown in FIG. 5). It should be noted that, a touch
display apparatus with a resolution of 1280.times.720 RGB is taken
as an example herein. 640 gate lines are generated at each side of
the screen on tight and left. Specifically, the on-screen gate
circuit 106 is formed by connecting 640 RS Cell sub-circuits (the
RS Cell is used as a latch). In the RS Cell sub-circuit, VGL end is
connected to a voltage source provided to the gate line for turning
off a thin film transistor TFT, CK end is connected to a clock
input signal, SP end is a data input end, and OUT is an output
end.
[0088] Logic control signals provided to the RS Cell sub-circuit by
the gate driving unit 101 include: CK1_L, CK2_L, SP_L, CK1_R,
CK2_R, SP_R and VGLO for driving the gate lines G.sub.1, G.sub.2 .
. . G.sub.M (M is 1280).
[0089] Reference is made to FIG. 8, a schematic diagram of a gate
driving unit 101 shown in FIG. 5 according to an embodiment is
shown. The gate driving unit 101 includes a charge pump 1012, a
voltage regulator 1013, multiple high voltage driving units 1015, a
power signal unit 1014 and a timing control unit 1011.
[0090] The charge pump 1012 includes a first output terminal
configured to output a first voltage VGH (15V) for driving the thin
film transistor to turn on; and a second output terminal configured
to output a second voltage VGL1 (-12V) for controlling the thin
film transistor to turn off.
[0091] The voltage regulator 1013 is connected to the second output
terminal of the charge pump 1012 and is configured to adjust the
second voltage outputted by the charge pump 1012 to form a third
voltage VGL2 (-10V). The second voltage and the third voltage
correspond to a low level and a high level of the second pulse
signal 202 respectively.
[0092] An input terminal of the multiple high voltage driving units
1015 is connected to the first output terminal and the second
output terminal of the charge pump 1012 and the voltage regulator
1013. An output terminal of the high voltage driving units 1015 is
connected to the SP end, which is the data input terminal, of the
RS Cell sub-circuit and the CK end for outputting the logic control
signals CK1_L, CK2_L, SP_L, CK1_R, CK2_R and SP_R.
[0093] Specifically, the high voltage driving unit 1015 includes a
first PMOS transistor P1, a first NMOS transistor N1A and a second
NMOS transistor N1B. A source of the first PMOS transistor P1 is
connected to the first output terminal of the charge pump 1012
(provided with the first voltage VGH), and a gate of the first MOS
transistor P1 is connected to a first timing controller (not
shown). A source of the first NMOS transistor N1A is connected to
the second output terminal of the charge pump 1012 (provided with
the second voltage VGL), and a gate of the first NMOS transistor
N1A is connected to a third timing controller and a second timing
controller. A source of the second NMOS transistor N1B is connected
to the voltage regulator 1013 (provided with the third voltage
VGL2), a gate of the second NMOS transistor N1B is connected to the
second timing controller, and a drain of the second NMOS transistor
N1B is connected to a drain of the first NMOS transistor N1A and a
drain of the first PMOS transistor P1.
[0094] An input terminal of the power signal unit 1014 is connected
to the second output terminal of the charge pump 1012 and the
voltage regulator, and an output terminal of the power signal unit
1014 is connected to a voltage source VGL input terminal of the
multiple RS Cell sub-circuits.
[0095] Specifically, the power signal unit 1014 includes a third
NMOS transistor N2A and a fourth NMOS transistor N2B. A source of
the third NMOS transistor N2A is connected to a third output
terminal of the charge pump 1012, and a gate of the third NMOS
transistor N2A is connected to the second timing controller. A
source of the fourth NMOS transistor N2B is connected to an output
terminal of the voltage regulator 1013, a gate of the fourth NMOS
transistor N2B is connected to the second timing controller, and a
drain of the fourth NMOS transistor N2B is connected to a drain of
the third NMOS transistor.
[0096] The timing control unit 1011 includes a first timing
controller (not shown). The first timing controller is connected to
the high voltage driving unit 1015 for driving the high voltage
driving unit 1015 to output the first voltage VGH and the second
voltage VGL1 alternately to provide the first voltage VGH and the
second voltage VGL1 to the multiple gate lines in a time-sharing
manner, thereby providing a driving signal to multiple gate lines
in a time-sharing manner to be used in the display stage.
[0097] The timing control unit 1011 further includes a second
timing controller. The second timing controller is connected to the
high voltage driving unit 1015 and the power signal unit 1014. The
second timing controller is configured to drive the power signal
unit 1014 to output the second voltage VGL1 and the third voltage
VGL2 to an input terminal of the voltage source VGL of the RS Cell
sub-circuit alternately. The second timing controller is further
configured to control the high voltage driving unit 1015 to output
the second voltage VGL1 and the third voltage VGL2 to the data
input terminal SP of the RS Cell sub-circuit alternately, so that a
signal from the voltage source VGL input terminal of the RS Cell
sub-circuit is outputted to the output terminal OUT of the RS Cell
sub-circuit to provide the second pulse signal 202 to multiple gate
lines to be used in the touch sensing stage.
[0098] The timing control unit 1011 further includes a total timing
controller (not shown). The total timing controller is connected to
the first timing controller and the second timing controller, and
is configured to control the first timing controller to perform the
driving during the display stage and control the second timing
controller to perform the driving during the touch sensing
stage.
[0099] Reference is made to FIG. 9, a schematic diagram of a data
line driving unit shown in FIG. 5 according to an embodiment is
shown. Specifically, the data line driving unit includes a timing
control unit 1011 and multiple data line signal buffers 1023.
[0100] The multiple data line signal buffers 1023 correspond to
multiple data lines S.sub.1, S.sub.2 . . . . S.sub.N
respectively.
[0101] The data line signal buffer 1023 includes a positive driving
circuit 1021 and a negative driving circuit 1022.
[0102] An output terminal of the positive driving circuit 1021 is
connected to the corresponding one of the data lines for generating
a first pixel voltage driving liquid crystal molecules to rotate
towards a first direction as the display signal, and a first switch
T1A is arranged near the output terminal of the positive driving
circuit.
[0103] An output terminal of the negative driving circuit 1022 is
connected to the corresponding one of the data lines for generating
a second pixel voltage driving liquid crystal molecules to rotate
towards a second direction as a display signal, and a second switch
T1D is arranged near the output terminal of the negative driving
circuit.
[0104] The data line driving unit further includes a third switch
T1B and a fourth switch T1C. One end of the third switch T1B is
connected to a voltage source VSP (a voltage of which is 2V), and
the other end of the third switch T1B is connected to an output
terminal of the data line driving unit. One end of the fourth
switch T1C is connected to the ground, and the other end of the
fourth switch T1C is connected to the output terminal of the data
line driving unit.
[0105] The timing control unit 1011 further includes a third timing
controller (not shown). The third timing controller is driven by
the total timing controller during the display stage, and is
connected to the positive driving circuit 1021 and the negative
driving circuit 1022. The third timing controller is configured to
drive the first switch T1A and the second switch T1D to be switched
on alternately, so that the positive driving circuit and the
negative driving circuit output the first pixel voltage and the
second pixel voltage respectively.
[0106] The timing control unit 1011 further includes a fourth
timing controller. The fourth timing controller is driven by the
total timing controller during the touch sensing stage, and is
configured to drive the third switch T1B (not shown) and the fourth
switch T1C to be switched on alternately, so as to output the third
pulse signal 203 with a high level being a voltage of the voltage
source and a low level of 0V in a time-sharing manner.
[0107] Reference is made to FIG. 10, which is a schematic diagram
of a common electrode driving unit shown in FIG. 1 according to an
embodiment. The common electrode driving unit includes a touch
detection circuit 1033, a common electrode driving buffer 1032 and
a timing control unit 1011.
[0108] The touch detection circuit 1033 is connected to multiple
electrode units of the common electrode 105 via first switches K1A,
K2A . . . KNA respectively, and is configured to provide the first
pulse signal to the multiple electrode units in a case that the
first switches K1A, K2A . . . KNA are switched on for realizing
touch detection.
[0109] The common electrode driving buffer 1032 is connected to the
multiple electrode units of the common electrode 105 via second
switches K1B, K2B . . . KNB respectively, and is configured to
provide the common voltage signal to the multiple electrode units
in a case that the second switches K1B, K2B . . . KNB are switched
on.
[0110] The timing control unit 1011 is connected to the first
switches K1A, K2A . . . KNA and the second switches K1B, K2B . . .
KNB. The timing control unit 1011 is configured to drive the first
switches K1A, K2A . . . KNA to be switched on during the touch
sensing stage so that the touch detection circuit 1033 performs
self-capacitance detection on the multiple electrode units of the
common electrode 105. The timing control unit 1011 is further
configured to drive the second switches K1B, K2B . . . KNB to be
switched on during the display stage so as to control the common
electrode driving buffer 1032 to provide the common voltage signal
to the multiple electrode units of the common electrode 105.
[0111] It should be noted that, FIG. 8, FIG. 9 and FIG. 10 show
specific implementations of the gate driving unit 101, the data
line driving unit 102 and the common electrode driving unit 103
respectively, which is not limited in the present disclosure. In
another embodiment, the gate driving unit 101, the data line
driving unit 102 and the common electrode driving unit 103 may be
implemented in other circuit configuration.
[0112] Alternatively, in other embodiment, the gate driving unit
(or the data line driving unit) of the driving circuit may realize
only the display function. During the touch sensing stage, the data
line driving circuit provides a pulse signal corresponding to the
first signal to the data line (or the gate line driving circuit
provides a pulse signal corresponding to the first signal to the
gate line). That is, by only reducing the interference of parasitic
capacitor formed by the data line (or the gate line) and the common
electrode to the touch detection, the accuracy of the touch
detection is improved.
[0113] It should be noted that, in the above embodiment, the third
signal is a signal provided to the data line by the driving
circuit, charge and discharge capacity of a capacitor is decreased
by using the third signal provided to the data line and the first
signal provided to the common electrode, which is not limited in
the present disclosure. In other embodiment, the third signal may
not be a signal provided to the data line.
[0114] Reference is made to FIG. 11, a schematic diagram of a touch
display apparatus according to another embodiment of the present
disclosure is shown. The similarities between this embodiment and
the embodiment shown in FIG. 5 are not described. This embodiment
is different from the embodiment shown in FIG. 5 in that, the
driving circuit is coupled to the data line via the switch (no
shown). The third signal 303 in this embodiment is a signal for
controlling the switch to be switched off and may control the data
line to enter a floating state during the touch sensing stage. In
the floating state, the data line connected to the driving circuit
during the display stage is disconnected from the driving circuit
during the touch sensing stage.
[0115] Thus, the data line is disconnected from the driving circuit
during the touch sensing stage and is not provided with any signal.
Hence, during the touch sensing stage, in a capacitor formed by the
common electrode and the data line, an electrode plate
corresponding to the data line is not connected to any device, and
the capacitor is not charged and discharged, thus the charge and
discharge capacity is decreased and the accuracy of the touch
detection is improved.
[0116] Specifically, the similarities between the driving circuit
having both the display function and the touch detecting function
and the previous embodiment are not described. The driving circuit
differs from that in the previous embodiment in that, the driving
circuit further includes: switches arranged between the data line
driving unit and the multiple data lines, and the data line driving
unit is configured to provide a pixel voltage to the data line as a
display signal in a case that the switch is on; and the timing
control unit is connected to the switch, the timing control unit is
configured to control the switch to be switched on during the
display stage to control the data line driving unit to provide the
pixel voltage to the data line, and the timing control unit is
further configured to control the switch to be switched off during
the touch sensing stage via the third signal 303 to control the
data line to enter a floating state, to decrease the interference
of the parasitic capacitor formed by the data line and the common
electrode to the touch detection during the touch sensing
stage.
[0117] It should be noted that, in the embodiment shown in FIG. 11,
the gate driving unit further provides the second pulse signal 302
with a same frequency, a same phase and a same amplitude as the
first pulse signal 301 to the multiple gate lines G.sub.1, G.sub.2
. . . G.sub.M to reduce the interference of the parasitic capacitor
formed by the common electrode and the gate line and the
interference of the parasitic capacitor formed by the common
electrode and the data line. In other embodiment, the gate driving
unit of the driving circuit may realize only the display function,
the driving circuit during the touch sensing stage controls the
data line to enter a floating state. That is, by only reducing the
interference of the parasitic capacitor between the data line and
the common electrode to the touch detection, the accuracy of the
touch detection is improved.
[0118] Accordingly, it is further provided a driving circuit
according to the present disclosure, which is applied to a touch
display apparatus. The touch display apparatus includes: a first
substrate; a second substrate arranged opposite to the first
substrate, where gate lines, data lines and thin film transistors
are arranged on a surface of the second substrate facing towards
the first substrate; a liquid crystal layer arranged between the
first substrate and the second substrate; and a common electrode
arranged between the first substrate and the second substrate and
used as a touch sensing electrode during a touch sensing stage.
[0119] The driving circuit includes: a first driving module
configured to provide a first signal to the common electrode for
realizing touch detection during the touch sensing stage; a second
driving module configured to provide a second signal to the gate
line during the touch sensing stage, where the second signal is
used to control the thin film transistor to be switched off and is
used to decrease charge and discharge capacity of a capacitor
formed by the common electrode and the gate line; and/or a third
driving module configured to provide a third signal to the data
line during the touch sensing stage, where the third signal is used
to decrease charge and discharge capacity of a capacitor formed by
the common electrode and the data line.
[0120] Specifically, the first driving module includes a common
electrode driving unit and a part of the timing control unit for
driving the common electrode driving unit; the second driving
module includes a gate driving unit and a part of the timing
control unit for driving the gate driving unit; and the third
driving module includes a data line driving unit and a part of the
timing control unit for driving the data line driving unit.
[0121] The related description of the driving circuit has been
given in the related embodiment of the touch display apparatus,
which is not described herein.
[0122] It is further provided a driving method for driving a touch
display apparatus according to the present disclosure. The touch
display apparatus includes: a first substrate; a second substrate
arranged opposite to the first substrate, where gate lines, data
lines and thin film transistors are arranged on a surface of the
second substrate facing towards the first substrate; a liquid
crystal layer arranged between the first substrate and the second
substrate; and a common electrode arranged between the first
substrate and the second substrate and used as a touch sensing
electrode during a touch sensing stage.
[0123] The driving method includes:
[0124] providing a driving signal to the multiple gate lines
sequentially, providing a display signal to the data line, and
providing a common voltage signal to multiple electrode units of
the common electrode, during a display stage; and
[0125] providing a first signal to the common electrode for
realizing touch detection during the touch sensing stage; providing
a second signal to the gate line in the process of providing the
first signal to the common electrode, where the second signal is
used to control the thin film transistor to be switched off and is
used to decrease charge and discharge capacity of a capacitor
formed by the common electrode and the gate line; and/or providing
a third signal in the process of providing the first signal to the
common electrode, where the third signal is used to decrease charge
and discharge capacity of a capacitor formed by the common
electrode and the data line.
[0126] With the driving method according to the present disclosure,
during the touch sensing stage, the first signal is provided to the
common electrode, the second signal is provided to the gate line
and/or the third signal is provided, thus charge and discharge
capacity of a parasitic capacitor formed by the common electrode
and the gate line and/or the data line is decreased. Interference
of the parasitic capacitor to the touch detection is reduced by
decreasing the charge and discharge capacity of the parasitic
capacitor, thus the accuracy of touch detection is improved.
[0127] Optionally, the second signal is a pulse signal with a same
frequency, a same phase and a same amplitude as the first signal,
so that the capacitor formed by the common electrode and the gate
line is not charged and discharged, that is, the charge and
discharge capacity is decreased to zero, which is not limited in
the present disclosure. In other embodiment, the second is a pulse
signal with a same frequency and a same phase as the first signal,
and the charge and discharge capacity can also be decreased.
[0128] Optionally, in the process of providing the third signal,
the third signal is provided to the data line. The third signal is
a pulse signal with a same frequency, a same phase and a same
amplitude as the first signal, so that the capacitor formed by the
common electrode and the data line is not charged and discharged,
that is, the charge and discharge capacity is decreased to zero to
reduce the interference of the parasitic capacitor, which is not
limited in the present disclosure. In other embodiment, the third
signal is a pulse signal with a same frequency and a same phase as
the first signal, and the charge and discharge capacity can also be
decreased.
[0129] Optionally, the third signal may not be a signal provided to
the data line, and may be a signal used to control the data line to
enter a floating state. Specifically, the data line may be coupled
to the driving circuit via a switch, and the third signal may be a
signal for controlling the driving circuit to be disconnected from
the data line so as to control the data line to enter a floating
state, so that the capacitor formed by the common electrode and the
data line is not charged and discharged, that is, the charge and
discharge capacity is decreased to zero.
[0130] In the driving method according to the present disclosure, a
form of the first signal, the second signal or the third signal is
not limited, which may be a pulse signal, such as a square signal,
a sine wave signal or a stair-step signal, or may not be a pulse
signal.
[0131] It should be noted that, the driving method according to the
present disclosure may be performed by the driving circuit
according to the present disclosure, or may be performed by other
driving circuit, which is not limited in the present
disclosure.
[0132] Although the present invention is disclosed above, the
present invention should not be limited thereto. Various changes
and modifications can be made by those skilled in the art without
departing from the spirit and scope of the present invention.
Therefore, the scope of protection of the present invention should
be defined by the appending claims.
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