KR20140083214A - Display device with integrated touch screen and method for driving the same - Google Patents

Abstract

The present invention relates to a display device integrated with a touch screen, which includes a panel including a plurality of electrodes divided into n groups (n is an integer equal to or greater than 2); a display driver IC for applying a common voltage to the electrodes or dividing the electrodes into n groups to apply a touch scan signal to each of the n groups according to driving modes of the panel; and a touch IC for generating the touch scan signal to be applied to the display driver IC. The display driver IC applies the touch scan signal to each of the n groups at a predetermined time interval, and, in each of n groups, each electrode belonging to a touch unit in a predetermined region includes at least one electrode.

Description

TECHNICAL FIELD [0001] The present invention relates to a touch-screen integrated display device and a driving method thereof. BACKGROUND OF THE INVENTION [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly, to a touch screen integrated display device.

The touch screen may be a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an electroluminescence device (EL) , And is a kind of an input device that presses (presses or touches) a touch sensor in a touch screen while the user views the image display device and inputs predetermined information.

In particular, in recent years, in order to reduce the size of a portable terminal such as a smart phone, a tablet PC, and the like, there has been an increasing demand for an in-cell type touch screen integrated display device in which elements constituting a touch screen are built in a display device have.

In a general insensitive type touch screen display device, touch data is transmitted to the system once for each vertical synchronization signal (Vsync) defining one frame period. Hereinafter, driving of a conventional in-cell type touch screen integrated type display device will be described with reference to FIG.

1 is a timing diagram of signals in a display period and a touch sensing period according to a synchronization signal of a general touch screen integrated display device.

As shown in FIG. 1, a general in-cell type self-capacitance type touch screen integrated type display device is driven by time division within a frame within a display period and a touch sensing period in accordance with a synchronization signal.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a touch screen integrated type display device capable of determining whether or not a touch input is performed and determining whether or not to perform low power operation.

According to an aspect of the present invention, there is provided a touch screen integrated type display device including: a panel including a plurality of electrodes divided into n groups (n is an integer of 2 or greater); A display driver IC for applying a common voltage to the electrodes according to a driving mode of the panel or dividing the electrodes into n groups and applying a touch scan signal to the divided n groups; And a touch IC for generating the touch scan signal and applying the touch scan signal to the display driver IC, wherein the display driver IC applies the touch scan signal to the n groups with a predetermined time difference, And includes at least one electrode for each electrode belonging to a touch unit in a certain region.

According to an aspect of the present invention, there is provided a method of driving a touch screen integrated display device including a panel including a plurality of electrodes divided into n groups (where n is an integer of 2 or greater) A display driver IC for dividing the electrodes into n groups and applying touch scan signals to the divided n groups, a touch IC for generating and applying the touch scan signal to the display driver IC, The method comprising: applying the common voltage to all the electrodes during a display period of an n-th frame; Applying the touch scan signal to a group during a touch period of the nth frame; Confirming whether the panel is touch input; Applying the touch scan signal to the n groups with a predetermined time difference when the touch input is not present on the panel; And applying the touch scan signal to another group during the touch period of the nth frame, wherein each of the n groups includes at least one electrode for each electrode belonging to a touch unit of a certain region.

According to various embodiments of the present invention, it is possible to drive the panel with low power by determining in advance whether touch input is performed in the touch screen integrated display device.

In addition, according to various embodiments of the present invention, it is possible to confirm whether or not touch input of the entire panel is performed by one touch sensing scan signal.

1 is a timing diagram of a display period and a touch sensing period according to one vertical synchronizing signal of a general touch screen integrated display device;
2 is a block diagram of a touch screen integrated display device according to an embodiment of the present invention;
3 is a detailed view illustrating a connection relationship between a panel of a touch screen integrated display device and a display driver IC according to an exemplary embodiment of the present invention;
4 is a detailed view illustrating a connection relationship between a panel of a touch screen integrated type display device and a display driver IC according to another embodiment of the present invention;
5 is a detailed view illustrating a connection relationship between a panel of a touch screen integrated display device and a display driver IC according to another embodiment of the present invention;
6 is a flowchart illustrating a method of driving a touch screen integrated type display apparatus according to an embodiment of the present invention; And
FIG. 7 is a timing diagram of a display period and a touch sensing period according to one vertical synchronizing signal of the integrated touch screen display device according to an exemplary embodiment of the present invention; FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, a touch screen integrated type display device according to various embodiments of the present invention will be described as an example of a liquid crystal display device for convenience of explanation, and the present invention is not limited thereto, and a field emission display device, a plasma display panel , An electroluminescent display device, an electrophoretic display device, and the like. In addition, a description of the general configuration of the liquid crystal display device will be omitted.

FIG. 2 is a view illustrating a configuration of a touch screen integrated type display device according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a connection relationship between a panel of a touch screen integrated type display device and a display driver IC according to an exemplary embodiment of the present invention in detail Fig.

As shown in FIG. 2, the integrated touch screen type display device according to an exemplary embodiment of the present invention includes a panel 100, a display driver IC 200, and a touch IC 300.

First, the panel 100 has a built-in touch screen (not shown), and the touch screen performs a function of detecting a touch position of the user. Particularly, And is a self-capacitance type in-cell type touch screen which is driven in time division.

The panel 100 may be configured such that a liquid crystal layer is formed between two substrates. In this case, the lower substrate of the panel 100 includes a plurality of gate lines, a plurality of data lines intersecting the gate lines, a plurality of TFTs (thin film transistors) formed at the intersections of the data lines and the gate lines, The pixels are arranged in a matrix by the intersection structure of the gate lines.

 Further, the panel 100 includes electrodes 101 divided into two groups and a plurality of wirings. In the touch screen integrated type display device shown in Fig. 2, although the electrodes are divided into two groups such as G1 and G2 in total, this is not applicable to one embodiment, and as shown in Fig. 4, a total of three groups G1, G2 and G3 And may be divided into a total of four groups such as G1, G2, G3, and G4 as shown in FIG. In other words, in the touch screen integrated display device according to various embodiments of the present invention, the electrodes may be divided into n groups (n is an integer of 2 or more).

The panel according to an embodiment of the present invention includes a touch unit as shown in FIG. 2, wherein the touch unit is not a specific component, and may be defined as a minimum range in which a user's touch is input. In other words, if the user's touch input is a touch input by a finger, it may be the minimum range in which the finger touches.

Here, the plurality of electrodes 101 are formed so as to overlap with a plurality of pixel electrodes in the pixel region of the panel 100. In other words, the plurality of electrodes is not formed for each pixel but is formed in an area overlapping a plurality of pixels.

When the driving mode of the panel is the touch driving mode, the touch IC 300 is operated as a common electrode for driving the liquid crystal together with the pixel electrode formed in each pixel, And a touch electrode that senses a touch position by a touch scan signal applied from the touch sensor.

The plurality of electrodes 101 are divided into two groups 110 and 120, and each of the wirings connects the plurality of electrodes 101 to the display driver IC 200. Accordingly, the common voltage and the touch scan signal output from the display driver IC 200 are applied to the plurality of electrodes 101 through the respective wirings.

Next, the display driver IC 200 applies a common voltage to the plurality of electrodes 101 according to the driving mode of the panel 100, or applies a touch scan signal to each of the divided two groups.

In other words, if the driving mode of the panel 100 is the display driving mode, the common voltage is applied to the plurality of electrodes, and if the driving mode of the panel is the touch driving mode, the touch scan signal is applied to the divided two groups.

For example, if the driving mode of the panel is the display driving mode, a common voltage is applied to all the electrodes of the panel. If the driving mode of the panel is the touch driving mode, And applies a touch scan signal to the G2 group 120 to detect whether the touch input is performed on the panel. If no touch input is detected in the G1 group 110, a touch scan signal is applied to the G2 group 120 to which the touch scan signal is not applied for a predetermined time according to the low power mode, If a touch input is detected by any one of the groups G1 and G2, the touch scan signal is sequentially applied to the divided two groups during the touch sensing period of the next frame, To perform sensing.

As shown in FIG. 2, each of the groups G1 and G2 includes at least one electrode for each electrode belonging to a touch unit of a certain region. In particular, the touch screen integrated display according to an embodiment of the present invention includes two groups Each of the electrodes includes two electrodes for each of the electrodes belonging to the touch unit, so that it is possible to detect whether all the electrodes of the panel are touched by applying a touch scan signal to only one group. Here, the touch unit is not a specific component, and may be defined as a minimum range in which the user's touch is input. In other words, if the user's touch input is a touch input by a finger, it may be the minimum range in which the finger touches. In addition, in the touch screen integrated type display device according to an embodiment of the present invention, a certain region may be a region corresponding to four electrodes of two rows and two columns.

3, the display driver IC 200 is for driving a plurality of electrodes 101 with a common electrode or a touch electrode, and includes a common voltage generator 210, a switching unit 220, A signal generation unit 230, a switching control signal generation unit 240, a time delay adjuster 250, and the like.

The common voltage generator 210 generates the common voltage Vcom and applies it to the switching unit.

In other words, if the driving mode of the panel is the display driving mode, a common voltage to be applied to the plurality of electrodes is generated and applied to the switching unit 220.

The synchronization signal generation unit 230 generates a synchronization signal indicating a drive mode of the panel.

For example, when the driving mode of the panel is the display driving mode, the common voltage Vcom generated by the common voltage generating unit is applied to the electrodes 101 through the switching unit 220, 101) to generate a synchronization signal.

The switching control signal generator 240 may be configured such that the electrodes 101 are connected to the common voltage generator 210 at the same time or the electrodes 101 are connected to the touch IC 300 And generates a control signal to be connected to each group.

The switching unit 220 may include a plurality of first switching units 221 and a plurality of second switching units 222 and applies a common voltage and a touch scan signal to the electrodes 101.

In other words, the switching unit 220 simultaneously applies a common voltage to the plurality of electrodes 101 in accordance with the synchronizing signal of the synchronizing signal generating unit 230 and the control signal of the switching control signal generating unit 240, Apply the signal to each group.

For example, as shown in FIG. 3, the plurality of first switching units 221 may connect the common voltage generator 210, the touch sensing unit 300, and the second switching unit 222, If the synchronizing signal of the synchronizing signal generator 230 is a synchronizing signal indicating the display driving mode, the common voltage generator 210 and the plurality of second switching units 222 are connected to each other, The touch IC 300 and the plurality of second switching units 222 are connected to each other. The plurality of first switching units 221 may be a 2: 1 multiplexer.

The plurality of second switching units 222 may connect the plurality of first switching units to only one electrode of each group, and the control signal of the switching control signal generating unit 240 may be controlled according to a synchronization signal indicating the display driving mode The first switch 221 and the plurality of electrodes are connected to each other, and if the control signal is a control signal according to the synchronization signal indicating the touch driving mode, the plurality of first switching units 221 and the plurality of electrodes .

If there is no touch input on the panel during the touch sensing period of the G1 group after connecting the plurality of first switching units to the G1 group 110, the plurality of second switching units 222 may transmit the G2 group If a touch input has been made to the panel during the touch sensing period of the previous frame, the first switching units may be sequentially connected to the G1 group 110 and the G2 group 120. FIG.

If there is no touch input on the panel after performing the touch sensing operation for any one group, the time delay adjuster 250 adjusts the application time of the touch scan signal so that the touch scan signal may be applied to the next group after a time delay according to the low power mode It plays a role of delay.

Referring again to FIG. 2, the touch IC 300 applies a touch scan signal to a plurality of electrodes 101 through a display driver IC 200, senses a change in capacitance of the electrodes, And performs a function of detecting whether or not it is touched.

For example, the touch IC 300 according to an exemplary embodiment of the present invention may include a touch scan signal generator for generating a touch scan signal to be supplied to a plurality of electrodes of the panel for touch sensing. The touch scan signal may be a touch driving voltage, and the touch driving voltage may be greater than a common voltage applied to the plurality of electrodes of the panel for driving the display. In this case, the touch driving voltage has the voltage corresponding to the common voltage as the low level voltage, and the higher voltage can have the high level voltage.

In addition, the touch IC 300 according to an embodiment of the present invention includes a touch sensing unit that receives a touch sensing signal from a plurality of electrodes 101, calculates touch coordinates, and performs a function of sensing a touch by a user . Here, the calculated touch coordinates are transmitted to the system unit of the display device to enable the touch coordinates of the user generated on the panel to be sensed.

Hereinafter, a touch screen integrated display device according to another embodiment of the present invention will be described in detail with reference to FIGS. 4 and 5. FIG.

FIG. 4 is an embodiment of a panel including electrodes divided into three groups, and FIG. 5 is an embodiment of a panel including electrodes divided into four groups.

Other configurations of the display driver IC 200 according to other embodiments of the present invention and other embodiments are described in detail in one embodiment of the present invention and therefore will not be described here.

4 is a detailed view illustrating a connection relationship between a panel of a touch screen integrated type display device and a display driver IC according to another embodiment of the present invention.

4, the display driver IC 200 according to another embodiment of the present invention applies a common voltage to a plurality of electrodes 101 in accordance with a driving mode of the panel 100, The touch scan signal is applied to each group.

In other words, when the driving mode of the panel 100 is the display driving mode, the common voltage is applied to the plurality of electrodes, and when the panel driving mode is the touch driving mode, the touch scan signals are applied to the divided three groups.

For example, if the driving mode of the panel is the display driving mode, a common voltage is applied to all the electrodes of the panel. If the driving mode of the panel is the touch driving mode, Applies a touch scan signal to the panel G2 to detect whether or not the touch input is performed on the panel, and applies a touch scan signal to the panel G3 to detect whether the touch input is performed on the panel.

If the touch input is not detected in the G1 group 110, a touch scan signal is applied to the G2 group 120 to which the touch scan signal was not applied after a predetermined time delay according to the low power mode, If no touch input is detected in the G1 and G2 groups, a touch scan signal is applied to the G3 group 130 after a predetermined time delay according to the low power mode to detect whether or not a touch input is input to the panel.

If a touch input is detected in any one of the groups G1, G2, and G3, the touch scan signal is sequentially applied to the three divided groups during the touch sensing period of the next frame, .

As shown in FIG. 4, each of the groups G1, G2, and G3 includes at least one electrode for each electrode belonging to a touch unit of a certain area. Particularly, the touch screen integrated display device according to an embodiment of the present invention includes three One of the groups includes two electrodes for each electrode belonging to the touch unit so that it is possible to detect whether all the electrodes of the panel are touch input by applying a touch scan signal to only one group. Here, the touch unit is not a specific component, and may be defined as a minimum range in which the user's touch is input. In other words, if the user's touch input is a touch input by a finger, it may be the minimum range in which the finger touches. In addition, in the touch screen integrated type display device according to an embodiment of the present invention, a certain region may be a region corresponding to four electrodes of two rows and two columns.

5 is a detailed view illustrating a connection relationship between a panel of a touch screen integrated type display device and a display driver IC according to another embodiment of the present invention.

5, the display driver IC 200 according to another embodiment of the present invention applies a common voltage to a plurality of electrodes 101 in accordance with the driving mode of the panel 100, The touch scan signal is applied to each group.

In other words, when the driving mode of the panel 100 is the display driving mode, the common voltage is applied to the plurality of electrodes, and if the driving mode of the panel is the touch driving mode, the touch scan signal is applied to the divided four groups.

For example, if the driving mode of the panel is the display driving mode, a common voltage is applied to all the electrodes of the panel. If the driving mode of the panel is the touch driving mode, A touch scan signal is applied to the panel G2 to detect touch input, a touch scan signal is applied to the panel to detect touch input to the panel, The controller 140 applies a touch scan signal to the panel to detect whether or not the touch input is performed.

If the touch input is not detected in the G1 group 110, a touch scan signal is applied to the G2 group 120 to which the touch scan signal was not applied after a predetermined time delay according to the low power mode, If no touch input is detected in the G1 and G2 groups, a touch scan signal is applied to the G3 group 130 after a predetermined time delay according to the low power mode to detect whether or not a touch input is input to the panel. If no touch input is detected in the groups G1, G2, and G3, a touch scan signal is applied to the G4 group 140 after a predetermined time delay according to the low power mode to detect whether the touch input is input to the panel.

If a touch input is detected in any one of the groups G1, G2, G3, and G4, the touch scan signal is sequentially applied to the divided four groups during the touch sensing period of the next frame, To perform sensing.

As shown in FIG. 5, each of the groups G1, G2, G3, and G4 includes at least one electrode for each electrode belonging to a touch unit of a certain area. In particular, the touch screen integrated display device Each of the four groups includes one electrode for each electrode belonging to the touch unit so that it is possible to detect whether all the electrodes of the panel are touched by only applying a touch scan signal to one group. Here, the touch unit is not a specific component, and may be defined as a minimum range in which the user's touch is input. In other words, if the user's touch input is a touch input by a finger, it may be the minimum range in which the finger touches. In addition, in the touch screen integrated type display device according to an embodiment of the present invention, a certain region may be a region corresponding to four electrodes of two rows and two columns.

Hereinafter, a driving method of the touch screen integrated type display device as described above will be described with reference to FIGS. 6 and 7. FIG.

6 is a flowchart illustrating a method of driving a touch screen integrated type display device according to an embodiment of the present invention.

6, a method of driving a touch screen integrated type display device according to an exemplary embodiment of the present invention includes a panel including a plurality of electrodes divided into two groups, a method of applying a common voltage to a plurality of electrodes A display driver IC for dividing the electrodes into two groups and applying a touch scan signal to the divided two groups, and a touch IC for generating and applying a touch scan signal to the display driver IC A method, comprising: applying a common voltage to all electrodes during a display period of an nth frame; applying a touch scan signal to one group during a touch period of an n-th frame; Confirming whether the panel is touch input; Applying a touch scan signal to the n groups with a predetermined time difference when the touch input is not present on the panel; And applying a touch scan signal to another group during a touch period of an nth frame, wherein each of the n groups includes at least one electrode for each electrode belonging to a touch unit of a certain region.

First, a common voltage is applied to a plurality of electrodes during a first display period (S1).

For example, during the display period of the (n-1) -th frame, a plurality of electrodes are applied with a common voltage for operating as a common electrode for driving the display, and the plurality of electrodes are applied with a common voltage, And drives the liquid crystal.

Next, a step S2 of applying a touch scan signal to one of the groups during the first touch sensing period is performed.

For example, a touch sensing signal is applied to the G1 group 110 during a touch sensing period of the (n-1) th frame. Here, the touch scan signal input to the G1 group is a touch scan signal for detecting whether or not the touch input is performed on the panel.

Next, a step S3 of confirming whether the touch input is performed on the panel is performed.

For example, it is determined whether a touch input is performed on the panel based on the touch sensing signal applied to the G1 group 110 in the (n-1) th frame.

If there is no touch input on the panel, step S4 is performed for a predetermined time delay according to the low power mode before the touch scan signal is applied to the G2 group 120, and a touch sensing signal is applied to the G2 group 120 (S5). Here, the touch scan signal input to the G2 group is a touch scan signal for detecting whether or not the touch input is performed on the panel.

A step S5 of applying a touch sensing signal to the G2 group 120 is performed and then a step S3 is performed to confirm whether or not the panel is touch input.

If there is a touch input on the panel, a common voltage is applied to the plurality of electrodes during the second display period (S6). During the second touch sensing period, the touch signal is sequentially applied to the two divided groups (Step S7). The touch scan signal sequentially applied to the divided two groups is a touch scan signal for detecting the touch position of the panel.

A step S7 of sequentially applying a touch sensing signal to the two groups is performed and then a common voltage is applied to the plurality of electrodes during a display period of the next frame S1.

2, each of the G1 and the G2 groups includes at least one electrode for each electrode belonging to a touch unit in a certain region, and in particular, a touch screen integrated type display apparatus according to an exemplary embodiment of the present invention, In the touch screen integrated display device according to an embodiment of the present invention, each of the two groups includes two electrodes for each electrode belonging to the touch unit, so that only a touch scan signal is applied to only one group, Enables detection of input.

Here, the touch unit is not a specific component, and may be defined as a minimum range in which the user's touch is input. In other words, if the user's touch input is a touch input by a finger, it may be the minimum range in which the finger touches.

That is, it is possible to confirm whether or not the entire panel is touch input by only applying a touch scan signal to any one of the groups. The touch scan signal is applied to another group after operating in the low power mode according to the touch input information, May be sequentially applied to the divided groups to reduce power consumption.

FIG. 7 is a timing diagram of signals for a display period and a touch sensing period according to one vertical synchronization signal of the integrated touch screen display device according to an exemplary embodiment of the present invention. Referring to FIG.

7 is a timing diagram illustrating a timing diagram in which a touch scan signal is applied to another group after a predetermined time delay if no touch input is performed on a panel when a touch scan signal is applied to any one of the two groups. Here, as shown in FIG. 2, a touch scan signal is applied to each group through a second switching unit (multiplexer), and a time delay is provided through a time delay controller in the display driver IC.

7, a common voltage is applied simultaneously through each second switching unit during the display driving period of each frame in FIG. 7. However, FIG. 7 is a timing diagram illustrating the timing of the time delay adjustment. The timing diagram is omitted.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: Panel 101: Electrode
110: first group 120: second group
130: third group 140: fourth group
200: Display driver IC 210: Common voltage generator
220: switching part 221: first switching part
222: second switching unit 230: synchronous signal generating unit
240: switching control signal generator 250: time delay adjuster
300: Touch IC

Claims (14)

a panel including a plurality of electrodes divided into n groups (n is an integer of 2 or more);
A display driver IC for applying a common voltage to the electrodes according to a driving mode of the panel or dividing the electrodes into n groups and applying a touch scan signal to the divided n groups; And
And a touch IC for generating and applying the touch scan signal to the display driver IC,
The display driver IC applies the touch scan signal to the n groups with a predetermined time difference,
Wherein each of the n groups includes at least one electrode for each electrode belonging to a touch unit of a certain region.
The method according to claim 1,
Wherein each of the n groups includes two electrodes for each of the electrodes belonging to the touch unit.
The method according to claim 1,
Wherein one of the n groups includes two electrodes for each electrode belonging to the touch unit.
The method according to claim 1,
And each of the n groups includes one electrode for each electrode belonging to the touch unit.
The method according to claim 1,
Wherein the predetermined region is a region corresponding to four electrodes of two rows and two columns.
The method according to claim 1,
The display driver IC includes:
A common voltage generator for generating the common voltage;
A switching unit for applying the common voltage and the touch scan signal to the electrodes;
And a time delay controller for adjusting an application time of the touch scan signal.
The method according to claim 6,
The switching unit includes:
And a plurality of n: 1 multiplexers.
a panel including a plurality of electrodes divided into n groups (n is an integer of 2 or more), a common voltage is applied to the electrodes, or the electrodes are divided into n groups, And a touch IC for generating and applying the touch scan signal to the display driver IC, the method comprising:
applying the common voltage to all the electrodes during a display period of an n < th >frame;
Applying the touch scan signal to a group during a touch period of the nth frame;
Confirming whether the panel is touch input;
Applying the touch scan signal to the n groups with a predetermined time difference when the touch input is not present on the panel; And
And applying the touch scan signal to another group during the touch period of the n-th frame,
Wherein each of the n groups includes at least one electrode for each electrode belonging to a touch unit of a predetermined region.
9. The method of claim 8,
If the panel has the touch input, applying the common voltage to all the electrodes during a display period of the (n + 1) th frame;
sequentially applying the touch scan signal to the divided n groups during a touch period of an (n + 1) th frame;
applying the common voltage to all the electrodes during a display period of an (n + 2) th frame; And
And applying the touch scan signal to one group during the touch period of the (n + 2) -th frame.
9. The method of claim 8,
If there is no touch input on the panel,
Performing the step of applying the touch scan signal to the other group during the touch period, and checking whether the touch input of the panel is performed again.
9. The method of claim 8,
Wherein each of the n groups includes two electrodes for each of the electrodes belonging to the touch unit.
9. The method of claim 8,
Wherein one of the n groups includes two electrodes for each electrode belonging to the touch unit.
9. The method of claim 8,
Wherein each of the n groups includes one electrode for each electrode belonging to a touch unit of a certain region.
9. The method of claim 8,
Wherein the predetermined region is a region corresponding to four electrodes of two rows and two columns.

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