KR102186170B1 - Touch sensor and driving method thereof - Google Patents

Abstract

The present invention relates to a touch sensor and a driving method thereof. The touch sensor comprises: a touch sensing units including a plurality of sensing nodes configured by j rows; a noise calculator to calculate noise data by each row of the sensing nodes using the sensing data from the touch sensing units; and a touch calculator to calculate touch data by subtracting full calculated noise data from corresponding sensing data when the noise data by each row is calculated by the noise calculator. The noise calculator sets noise data of each sensing node included in an m^th (1<=m<=j) row as sensing data received from the touch sensing unit. When it is determined that a touch event occurs from an n^th sensing node included in the m^th row, the noise calculator updates the noise data of the n^th sensing node as a sum of noise data of an (n-1)^th sensing node included in the m^th row and a tracking change amount.

Description

Touch sensor and its driving method TECHNICAL FIELD [TOUCH SENSOR AND DRIVING METHOD THEREOF}

The present invention relates to a touch sensor and a driving method thereof, and more particularly, to a touch sensor capable of improving touch sensitivity by removing the influence of display noise, and a driving method thereof.

With increasing interest in information display and increasing demand for use of portable information media, research and commercialization of display devices are focused on.

Examples of such display devices include a liquid crystal display device, a field emission display device, a plasma display device, and an organic light emitting display device. .

Among them, the organic electroluminescent display displays an image using an organic light emitting diode that generates light by recombination of electrons and holes, which has an advantage of having a fast response speed and driving with low power consumption.

Recent display devices include a touch sensor for receiving a user's touch input in addition to an image display function. Accordingly, the user can use the display device more conveniently through the touch sensor.

Various types of touch sensors are used, but among them, the capacitive touch sensor is capable of detecting the touch position by detecting the point at which the capacitance changes according to the contact of a person's hand or object. It is widely used in recent years due to its easy detection of touch and excellent accuracy.

However, the spatial gap between the display panel and the touch sensor has been reduced according to the trend of flexible organic electroluminescent display devices and small size and thinness, and accordingly, the size of display driving noise induced by the touch sensor increases, thereby obtaining desired touch sensing sensitivity. It is reaching the level of becoming impossible.

An object of the present invention is to provide a touch sensor and a driving method thereof capable of improving touch sensitivity by removing the influence of display noise.

The touch sensor according to an embodiment of the present invention calculates noise data for each row of the sensing node using a touch sensing unit including a plurality of sensing nodes consisting of j rows, and sensing data output from the touch sensing unit. A noise calculation unit that calculates touch data by subtracting the total noise data from the corresponding sensing data when the noise data for each row is calculated by the noise calculation unit, and the noise The calculation unit sets noise data of each sensing node included in the m (1≦m≦j)-th row as sensing data received from the touch sensing unit, and a touch event at the n-th sensing node included in the m-th row When it is determined that is generated, the noise data of the n-th sensing node may be updated to a value obtained by adding a tracking change amount to the noise data of the n-1 th sensing node included in the m-th row.

In addition, the noise calculating unit, when the sum of the difference between the sensing data of the nth sensing node and the n-1th sensing node and the amount of tracking change is greater than a preset threshold, a touch event occurs in the nth sensing node. It can be judged as.

In addition, the tracking change amount is set as an average of the difference in sensing data from the previous sensing node for each sensing node included in the m-th row, or at least one sensing node located before the n-th sensing node. It may be set as an average value of the difference between the sensing data and the sensing node.

In addition, when the sum of the tracking change amount and the difference in sensing data between the nth sensing node and the n-1th sensing node is greater than a preset threshold value, the noise calculating unit may include the n-th sensing node together with the n-th sensing node. It may be determined that a touch event has occurred in the first sensing node and the n+1th sensing node.

In addition, the touch sensing unit includes driving electrodes and sensing electrodes disposed to cross each other, and the driving electrodes are formed to be elongated in a row direction and arranged in a plurality along a column direction, and receive a touch driving signal, and the The sensing electrodes are formed long in the column direction, are arranged in a plurality along the row direction, and the sensing data may be provided to the noise calculating unit.

In the method of driving a touch sensor according to an embodiment of the present invention, the step of acquiring sensing data for each sensing node from a touch sensing unit including a plurality of sensing nodes consisting of j rows and k columns, the sensing data Computing the noise data for each row of the sensing node, and when the calculation of the noise data for each row is completed, calculating touch data by subtracting the total calculated noise data from the corresponding sensing data, wherein the The calculating of noise data for each row of the sensing node using sensing data includes: the noise data of each sensing node included in the m (1 ≤ m ≤ j)-th row is converted to sensing data received from the touch sensing unit. And when it is determined that a touch event has occurred in the n (2≤n≤k)-th sensing node included in the m-th row, noise data of the n-th sensing node is included in the m-th row. It can be updated to a value obtained by adding the amount of tracking change to the noise data of the sensing node.

In addition, calculating noise data for each row of the sensing node using the sensing data includes a value obtained by adding the tracking change amount to the difference in sensing data of the n-th sensing node and the n-1th sensing node. If it is greater than the threshold value, it may be determined that a touch event has occurred in the nth sensing node.

In addition, the tracking change amount is set as an average of the difference in sensing data from the previous sensing node for each sensing node included in the m-th row, or at least one sensing node located before the n-th sensing node. It may be set as an average value of the difference between the sensing data and the sensing node.

In addition, calculating noise data for each row of the sensing node using the sensing data includes a value obtained by adding the tracking change amount to the difference in sensing data of the n-th sensing node and the n-1th sensing node. If it is greater than the threshold value, it may be determined that a touch event has occurred in the n-1th sensing node and the n+1th sensing node together with the nth sensing node.

In addition, the touch sensing unit includes driving electrodes and sensing electrodes disposed to cross each other, and the driving electrodes are formed to be elongated in a row direction and arranged in a plurality along a column direction, and receive a touch driving signal, and the The sensing electrodes are formed to be elongated in the column direction, are arranged in a plurality along the row direction, and provide the sensing data.

According to the present invention as described above, it is possible to provide a touch sensor capable of improving touch sensitivity and a driving method thereof by removing the influence of display noise.

1 is a schematic diagram of a display device including a touch sensor according to an exemplary embodiment of the present invention.
2 is a diagram showing a detailed configuration of a display device including a touch sensor according to an exemplary embodiment of the present invention.
3 is a diagram illustrating a touch sensing unit and a touch controller according to an embodiment of the present invention.
4 is a diagram illustrating a touch map reconstructed through sensing data output from a touch sensing unit according to an embodiment of the present invention.
5 is a diagram illustrating a touch map from which display noise is removed by a touch controller according to an embodiment of the present invention.
6 is a diagram illustrating a method of driving a touch sensor according to an embodiment of the present invention.
7A to 7F are diagrams for explaining a method of driving the touch sensor shown in FIG. 6.
8 is a diagram illustrating a method of driving a touch sensor according to another embodiment of the present invention.
9A to 9F are views for explaining a method of driving the touch sensor illustrated in FIG. 8.

Hereinafter, embodiments related to the present invention will be illustrated in the drawings and will be described in detail through detailed description. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, and it is to be understood that it includes all changes, equivalents, or substitutes included in the spirit and scope of the present invention. .

In describing the constituent elements of the present invention, terms such as first, second, A, B, (a), (b) may be used. These terms are only used to distinguish the component from other components, and the nature, order, or order of the component is not limited by the term. In addition, in the present specification, when a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected or connected to the other component, but each component It should be understood that another component may be "connected", "coupled" or "connected" between elements. In the case of "connected", "coupled" or "connected", it is understood to be physically "connected", "coupled" or "connected" as well as electrically "connected", "coupled" or "connected" as needed. Can be.

Terms such as "~ unit (unit)", "~ group", "~ ruler", and "~ module" described in this specification mean a unit that processes at least one function or operation, which is hardware, software, or hardware. And software. In addition, terms such as "include", "consist of" or "have" described in the present specification mean that the corresponding component may be included unless otherwise stated, excluding other components It should not be construed as being able to include other components.

In addition, it is intended to clarify that the division of the constituent parts in the present specification is merely divided by the main function that each constituent part is responsible for. That is, two or more constituent parts to be described below may be combined into one constituent part, or one constituent part may be divided into two or more according to more subdivided functions. In addition, each of the constituent units to be described below may additionally perform some or all of the functions of other constituent units in addition to its own main function, and some of the main functions of each constituent unit are different. It goes without saying that it may be performed exclusively by.

Hereinafter, a touch sensor and a driving method thereof according to an embodiment of the present invention will be described with reference to the drawings related to the embodiments of the present invention.

FIG. 1 is a schematic diagram of a display device including a touch sensor according to an exemplary embodiment of the present invention, and FIG. 2 is a detailed diagram illustrating a configuration of a display device including a touch sensor according to an exemplary embodiment of the present invention.

1 and 2, a display device including a touch sensor according to an embodiment of the present invention includes a touch sensor 100, a display panel 210, a display driving circuit 220, and a host 250. can do.

The touch sensor 100 may include a touch sensing unit 110 and a touch control unit 120.

The touch sensing unit 110 may be positioned on the display panel 210 and may perform a role of receiving a touch input by a user. In addition, a plurality of electrodes may be provided in order to sense a change in capacitance due to the touch.

The touch controller 120 controls the touch sensing unit 110 and senses a change in capacitance using sensing data output from the touch sensing unit 110 to detect whether or not a touch event has occurred and a location.

That is, the touch sensor 100 including the above-described touch sensing unit 110 and the touch control unit 120 may operate as a capacitive touch sensor.

The touch sensing unit 110 may be connected to the main FPCB 202 through a first flexible printed circuit board (FPCB) 201, and the touch control unit 120 is formed in an integrated circuit form to form a first FPCB. It can be located on 201.

Accordingly, the touch controller 120 may transmit and receive signals with the host 250 located in the main FPCB 202.

However, the location of the touch controller 120 is not limited thereto, and may be located in another location such as the main FPCB 202 or the like.

The display panel 210 includes a plurality of pixels and may display a predetermined image through the pixels.

For example, the display panel 210 may display an image under the control of the display driving circuit 220.

For example, the display panel 210 may be implemented as an organic light emitting display panel.

The display driving circuit 220 may control an image display operation of the display panel 210 by supplying a display driving signal to the display panel 210.

The display driving circuit 220 may generate a display driving signal by using the digital image data DAT and the timing signal Ts supplied from the outside.

For example, the display driving circuit 220 may receive image data DAT and a timing signal Ts from the host 250, and the timing signal Ts is a vertical synchronization signal and a horizontal synchronization signal. A signal (Horizontal Synchronization Signal), a main clock signal (Main Clock Signal), a data enable signal (Data Enable Signal) may be included.

Further, the display driving signal may include a scan signal, a data signal, and the like.

For example, the display driving circuit 220 may be formed in the form of an integrated circuit and mounted on the display panel 210. In addition, the second FPCB 203 may be connected to the main FPCB 202, and accordingly, the display driving circuit 220 may transmit and receive signals to and from the host 250 located in the main FPCB 202.

However, the position of the display driving circuit 220 is not limited thereto, and may be connected to the display panel 210 through, for example, a separate component (eg, FPCB).

The touch control unit 120 and the display driving circuit 220 may be separately positioned as shown, but are not limited thereto. That is, the touch control unit 120 and the display driving circuit 220 may be integrated into one chip.

In the case of the host 250, data may be exchanged with the touch controller 120 and the display driving circuit 220 through an interface. For example, the host 250 and the touch control unit 120 transmit and receive data through a low-frequency control interface such as I2C for transmitting touch coordinate information, and the host 250 and the display driving circuit 220 transmit image data. For this, you can use a high-speed data interface such as MIPI.

The display driving circuit 220 according to an embodiment of the present invention may include a scan driver 221, a data driver 222, and a timing controller 223.

The scan driver 221 may supply a scan signal to the display panel 210, and the data driver 222 may supply a data signal to the display panel 210.

The timing controller 223 may control the operation of the scan driver 221 and the data driver 222, and may receive digital image data DAT and a timing signal Ts from the host 250 for this purpose.

3 is a diagram showing a touch sensing unit and a touch control unit according to an embodiment of the present invention, and FIG. 4 is a view showing a touch map reconstructed through sensing data output from the touch sensing unit according to an embodiment of the present invention. 5 is a diagram illustrating a touch map from which display noise is removed by a touch controller according to an embodiment of the present invention.

Referring to FIG. 3, the touch sensing unit 110 may include a plurality of touch electrodes Tx and Rx.

For example, the touch electrodes Tx and Rx include a plurality of driving electrodes (or transmission electrodes, Tx1 to Txj) and a plurality of sensing electrodes (or reception electrodes, Rx1 to Rxk). can do.

The driving electrodes Tx1 to Txj are formed to be elongated in a row direction (eg, in the X-axis direction) and may be arranged in plural along a column direction (eg, in a Y-axis direction) crossing the row direction.

The sensing electrodes Rx1 to Rxk may be formed to be elongated in a column direction (eg, in a Y-axis direction) and may be arranged in a plurality in a row direction (eg, in an X-axis direction).

The driving electrodes Tx1 to Txj and the sensing electrodes Rx1 to Rxk are positioned to cross each other, thereby operating as a capacitive touch sensor.

The intersection of the driving electrodes Tx1 to Txj and the sensing electrodes Rx1 to Rxk may form a plurality of sensing nodes, and when a touch event occurs in the touch sensor 100, a location related to the touch event (sensing The mutual capacitance of the node) changes. The touch position may be detected by detecting a change in the capacitance of the sensing node.

For example, a plurality of sensing nodes including j rows and k columns may be formed through j driving electrodes Tx1 to Txj intersecting each other and k sensing electrodes Rx1 to Rxk.

For example, each of the driving electrodes Tx1 to Txj includes a plurality of first touch sensing cells 411 arranged at predetermined intervals along a row direction (eg, X-axis direction), and the first touch It may include a plurality of first connection patterns 412 electrically connecting the sensing cells 411 to each other.

In addition, each of the sensing electrodes Rx1 to Rxk includes a plurality of second touch sensing cells 421 arranged at predetermined intervals along a column direction (eg, Y-axis direction), and the second touch sensing A plurality of second connection patterns 422 electrically connecting the cells 421 to each other may be included.

In this case, the second touch sensing cells 421 may be distributedly disposed between the first touch sensing cells 411 so as not to overlap with the first touch sensing cells 411.

3 illustrates a case in which the first touch sensing cells 411 and the second touch sensing cells 421 have a polygonal shape, but the first touch sensing cells 411 and the second touch sensing cells ( The shape of 421) can be variously changed.

Further, the shapes of the driving electrodes Tx1 to Txj and the sensing electrodes Rx1 to Rxk are not limited thereto, and may be variously changed.

The driving electrodes Tx1 to Txj and the sensing electrodes Rx1 to Rxk may include a conductive material. For example, metals or alloys thereof may be included. The metals include gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), platinum. (Pt), etc. are mentioned.

Also, the driving electrodes Tx1 to Txj and the sensing electrodes Rx1 to Rxk may be made of a transparent conductive material. The transparent conductive material includes silver nanowire (AgNW), ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), AZO (Antimony Zinc Oxide), ITZO (Indium Tin Zinc Oxide), ZnO (Zinc Oxide), and SnO ₂ (Tin Oxide), Carbon Nano Tube, graphene, and the like. The driving electrodes Tx1 to Txj and the sensing electrodes Rx1 to Rxk may be formed of a single layer or multiple layers, respectively. The driving electrodes Tx1 to Txj and the sensing electrodes Rx1 to Rxk may be made of the same material or different materials.

The driving electrodes Tx1 to Txj and the sensing electrodes Rx1 to Rxk may be disposed on a substrate (not shown). Such a substrate may be implemented as a separate substrate or may be implemented as various components included in the display device. For example, the substrate may previously be an encapsulation layer of the display panel 210.

That is, the touch sensor 100 may be designed in an on-cell manner. For example, the touch sensing unit 110 may be disposed above the display panel 210.

The touch driver 121 may supply a touch driving signal Td to the touch sensing unit 110 to drive the touch sensor 100.

For example, the touch driver 121 may sequentially supply the touch driving signal Td from the first driving electrode Tx1 to the j-th driving electrode Txj. However, the present invention is not limited thereto, and the touch driver 121 may supply the touch driving signal Td in a time-division manner according to a different order, and also for a plurality of driving electrodes according to the characteristics of the touch driving signal Td. Simultaneous supply can also be used.

On the other hand, the spatial gap between the touch sensing unit 110 and the display panel 210 has been reduced to reduce the trend of miniaturization and thinness of the display device and the implementation of flexible characteristics, and accordingly, the touch sensing unit 110 and the display panel The influence of the parasitic capacitance (Cp) existing between (210) also increased.

This parasitic capacitance Cp mainly exists between the touch electrode included in the touch sensing unit 110 and the power surface 211 included in the display panel 210, and the voltage according to the pixel operation on the power surface 211 Since an IR drop occurs, display noise through the power surface 211 is induced in the touch sensing unit 110, causing a problem that a desired touch sensing sensitivity cannot be obtained.

In particular, referring to the touch map of FIG. 4, it can be seen that each row sharing the driving time of the driving electrodes Tx1 to Txj is affected by the same display noise, but the panel mismatch and the receiving end It can be seen that the influence of display noise for each row due to mismatch of the (sensing electrodes), etc., has a gentle slope change. The influence of the display noise increases as the screen change increases, and it is necessary to appropriately remove the noise of the display by tracking the change in the inclination.

In order to solve this problem, in the present invention, the noise calculation unit 122 and the touch calculation unit 123 are used.

That is, the noise calculation unit 122 may calculate noise data for each row of a sensing node having commonality of display noise by using the sensing data output from the touch sensing unit 110, and the touch calculation unit 123 When the noise calculation unit 122 completes the calculation of noise data for each row, touch data may be calculated by subtracting the calculated total noise data from the sensing data corresponding thereto.

In addition, with respect to the touch sensing unit 110 composed of sensing nodes composed of j rows and k columns, the noise calculating unit 122 is used to determine the noise of each sensing node included in the m (1 ≤ m ≤ j)-th row. Data is set as sensing data received from the touch sensing unit 110, and when it is determined that a touch event has occurred in the n-th sensing node included in the m-th row, noise data of the n-th sensing node is included in the m-th row. The noise data of the n-1 th sensing node and the tracking change amount may be summed.

In addition, the noise calculator 122 determines that a touch event has occurred in the n-th sensing node when the sum of the difference between the sensing data of the n-th sensing node and the n-1th sensing node and the amount of tracking change is greater than a preset threshold. can do.

In this case, the tracking change amount may be set as an average of a difference in sensing data from a previous sensing node for at least one sensing node located before the n-th sensing node in order to accurately track the change in display noise for each row of the sensing node. .

In general, in order to minimize the load on the hardware, the tracking change amount may be set as an average of a difference in sensing data from a previous sensing node for each sensing node included in the m-th row.

In addition, when the sum of the tracking change amount and the difference value between the nth sensing node and the n-1th sensing node is greater than a preset threshold, the noise calculating unit 122 senses the n-1th together with the nth sensing node. It can be determined that a touch event has occurred in the node and the n+1th sensing node.

Through this configuration, the display noise component for each row of the sensing node can be effectively calculated, and a touch map including effective touch data as shown in FIG. 5 can be calculated by subtracting the calculated display noise component from the sensing data.

Accordingly, the touch calculator 123 may determine a location where a touch event occurs on the touch sensor and its intensity by performing a predetermined logical operation based on the calculated touch data.

6 is a diagram illustrating a method of driving a touch sensor according to an embodiment of the present invention, and FIGS. 7A to 7F are views for explaining a method of driving the touch sensor shown in FIG. 6. In particular, in FIG. 6, a method of driving a touch sensor performed during one frame period has been described, and in FIG. 7A, for convenience of description, when the touch sensing unit 110 includes a plurality of sensing nodes consisting of 5 rows and 5 columns Is illustrated as an example.

Referring to FIG. 6, first, sensing data for each sensing node is obtained from the touch sensing unit 110 including a plurality of sensing nodes consisting of j (j is an integer of 2 or more) rows and k (k is an integer of 2 or more) columns. The step (ST100) may be performed. This step ST100 may be performed by the noise calculator 122 described above.

For example, when j and k are each set to 5, the touch sensing unit 110 may include a total of 25 sensing nodes consisting of 5 rows and 5 columns, through which the noise calculation unit 122 Sensing data S11 to S55 for each sensing node may be obtained (see FIG. 7A).

Thereafter, an operation (ST110) of grouping the acquired sensing data for each sensing node S11 to S55 for each row may be performed. This step ST110 may be performed by the noise calculating unit 122 described above.

For example, the acquired sensing data S11 to S55 for each sensing node may be grouped (G1 to G5) based on each row having common display noise (refer to FIG. 7B ).

In addition, the step (ST120) of setting (initializing) noise data (N11 to N55) of each sensing node to sensing data (S11 to S55) for each sensing node obtained from the touch sensing unit 110 may be performed. This step ST120 may be performed by the noise calculating unit 122 described above.

For example, noise data N11 to N55 of sensing nodes included in each grouped row may be set to the same value as the sensing data S11 to S55 for each sensing node corresponding thereto (see FIG. 7C ). Accordingly, noise data of each sensing node included in the m (1≦m≦j)-th row may be set as sensing data received from the touch sensing unit 110.

Thereafter, the step of updating the noise data for each group (G1 to G5) of the sensing nodes may be performed. This step may be performed by the noise calculator 122 described above, and when it is determined that a touch event has occurred in the n (2≤n≤k)-th sensing node included in the m-th row, the touch event is generated. The noise data of the nth sensing node may be updated to a value obtained by adding a tracking change amount to the noise data of the n-1th sensing node included in the mth row. For example, a method of updating noise data for the first group G1 located in the first row will be described.

First, an operation ST130 of calculating a tracking change amount of the first group G1 may be performed. For example, the tracking change amount may be set as an average of the difference between the sensing data D11 to D14 from the previous sensing node for each sensing node included in the first row (see FIG. 7D ). That is, the initial tracking change amount of the first group G1 may be set as an average change amount of sensing data calculated for all sensing nodes.

If the first group G1 includes k sensing nodes, the difference (D1n-1) of the sensing data between the nth sensing node and the n-1th sensing node is equal to the sensing data S1n of the nth sensing node and n -It may be set as a difference value between the sensing data S1n-1 of the first sensing node.

Thereafter, an operation (ST140) of determining whether a touch event has occurred in an n-th sensing node included in the first group G1 may be performed. This step ST140 may be performed by the noise calculating unit 122 described above.

As an example, the noise calculating unit 122 is the n-th sensing node included in the m-th row and the n-th sensing node when the sum of the difference of the sensing data and the tracking change amount is greater than a preset threshold, the n-th It may be determined that a touch event has occurred in the sensing node. That is, when the following equation is satisfied, it may be determined that a touch event has occurred in the n-th sensing node.

│Smn-Smn-1 + Vt│> REF

Here, Smn is the sensing data of the nth sensing node included in the mth row, Smn-1 is the sensing data of the n-1th sensing node included in the mth row, Vt is the tracking change amount, and REF is a preset threshold. .

For example, in the case of the second sensing node included in the first row (the first group G1), it is determined that a touch event has occurred when the following equation is satisfied, and otherwise, it may be determined that the touch event has not occurred. have.

│S12-S11 + Vt│> REF

When it is determined that a touch event has not occurred in the second sensing node included in the first row (first group G1), the noise data N12 of the second sensing node may be maintained without being updated (Fig. 7e), then the update step (ST150) of the tracking change amount may be performed. This step ST150 may be performed through the noise calculator 122 described above, and may be omitted if necessary.

For example, when it is determined that a touch event has not occurred in the n-th sensing node included in the m-th row, the tracking change amount is set as the difference in sensing data between the n-th sensing node and the previous sensing node, or It may be updated to a value obtained by an average of a difference in sensing data from a previous sensing node for each sensing node from a previously located specific sensing node to the n-th sensing node.

For example, if it is determined that a touch event has not occurred in the second sensing node included in the first row (first group G1), the tracking change amount is the difference in sensing data between the second sensing node and the first sensing node ( D11) can be updated.

Thereafter, an operation (ST170) of determining whether a touch determination operation for the current group G1 has been completed may be performed. Since the remaining sensing nodes remain in the first group G1, a step ST140 of determining whether to touch the third sensing node may be performed.

If it is determined that the touch event has not occurred in the third sensing node included in the first row (first group G1), the noise data N13 of the third sensing node may be maintained without being updated. . Also, the tracking change amount may be updated as an average value of the difference in sensing data D12 between the third sensing node and the second sensing node and the difference D11 in sensing data between the second sensing node and the first sensing node.

Thereafter, when it is determined that a touch event has not occurred in the fourth sensing node included in the first row (first group G1), the noise data N14 of the fourth sensing node may be maintained without being updated. . In addition, the tracking change amount is the difference in sensing data between the fourth sensing node and the third sensing node (D13), the difference in sensing data between the third sensing node and the second sensing node (D12), and between the second sensing node and the first sensing node. It may be updated as an average value of the difference in sensing data D11.

However, if the number of difference values of the sensing data used when calculating the tracking change amount increases, the burden on the hardware increases. In order to alleviate this, the number of difference values of the sensing data used when calculating the tracking change amount can be appropriately adjusted.

Thereafter, when it is determined that a touch event has occurred in the fifth sensing node included in the first row (first group G1), the step of updating the noise data N15 of the fifth sensing node (ST160) is performed. Can be.

For example, when it is determined that a touch event has occurred in the n-th sensing node included in the m-th row, the noise data of the n-th sensing node is traced to the noise data of the n-1th sensing node included in the m-th row. It can be updated with the sum of the changes.

For example, since it is determined that a touch event has occurred in the fifth sensing node included in the first row (first group G1), the noise data N15 of the fifth sensing node is the noise data of the fourth sensing node ( It may be updated to a value (N15') obtained by adding the current tracking change amount to N14).

Accordingly, since the operation of determining whether to touch the current group G1 has been completed (ST170), an operation (ST180) of determining whether noise data of all groups has been acquired may be performed. Therefore, each step (S130, ST140, ST150, ST160, ST170, ST180) for the remaining groups (G2 to G5) may be repeatedly performed, and finally as shown in FIG. 7F as noise data of all groups are obtained. Total noise data can be calculated.

When the calculation of the noise data for each row is completed, a step ST190 of calculating touch data may be performed by subtracting the calculated total noise data N11 to N55 ′ from the sensing data corresponding thereto. This step ST190 may be performed by the touch calculator 123 described above.

Through this, effective touch data in the form of FIG. 5 can be calculated, and through this, the location of the touch event and its intensity can be determined.

Meanwhile, the above-described tracking change amount update step ST150 may be omitted to minimize the load on the hardware. In this case, the tracking change amount initially calculated for each row in the tracking change amount calculation step ST130 (average change amount of sensing data calculated for all sensing nodes) may be maintained and used without the need to separately update the tracking change amount.

8 is a diagram illustrating a method of driving a touch sensor according to another embodiment of the present invention, and FIGS. 9A to 9F are diagrams for explaining a method of driving the touch sensor shown in FIG. 8. In particular, in FIG. 8, a method of driving a touch sensor performed during one frame period has been described, and in FIG. 9A, for convenience of description, when the touch sensing unit 110 includes a plurality of sensing nodes comprising 5 rows and 5 columns Is illustrated as an example.

Referring to FIG. 8, first, sensing data for each sensing node is obtained from a touch sensing unit 110 including a plurality of sensing nodes consisting of j (j is an integer of 2 or more) rows and k (k is an integer of 2 or more) columns. The step (ST200) may be performed. This step ST200 may be performed by the noise calculating unit 122 described above.

For example, when j and k are each set to 5, the touch sensing unit 110 may include a total of 25 sensing nodes consisting of 5 rows and 5 columns, through which the noise calculation unit 122 Sensing data S11 to S55 for each sensing node may be obtained (see FIG. 9A).

Thereafter, an operation (ST210) of grouping the acquired sensing data for each sensing node S11 to S55 for each row may be performed. This step ST210 may be performed by the noise calculator 122 described above.

For example, grouping (G1 to G5) may be performed on the acquired sensing data S11 to S55 for each sensing node based on each row having common display noise (see FIG. 9B).

In addition, the step (ST220) of setting (initializing) noise data (N11 to N55) of each sensing node to sensing data (S11 to S55) for each sensing node obtained from the touch sensing unit 110 may be performed. This step ST220 may be performed by the noise calculator 122 described above.

For example, noise data N11 to N55 of sensing nodes included in each grouped row may be set to the same value as the sensing data S11 to S55 for each sensing node corresponding thereto (see FIG. 9C ). Accordingly, noise data of each sensing node included in the m (1≦m≦j)-th row may be set as sensing data received from the touch sensing unit 110.

Thereafter, the step of updating the noise data for each group (G1 to G5) of the sensing nodes may be performed. This step may be performed by the noise calculator 122 described above, and when it is determined that a touch event has occurred in the n (2≤n≤k)-th sensing node included in the m-th row, the touch event is generated. The noise data of the nth sensing node may be updated to a value obtained by adding a tracking change amount to the noise data of the n-1th sensing node included in the mth row. For example, a method of updating noise data for the first group G1 located in the first row will be described.

First, an operation ST230 of calculating a tracking change amount of the first group G1 may be performed. For example, the tracking change amount may be set as an average of the difference in sensing data (D11 to D14) from the previous sensing node for each sensing node included in the first row (see FIG. 9D). That is, the initial tracking change amount of the first group G1 may be set as an average change amount of sensing data calculated for all sensing nodes.

If the first group G1 includes k sensing nodes, the difference (D1n-1) of the sensing data between the nth sensing node and the n-1th sensing node is equal to the sensing data S1n of the nth sensing node and n -It may be set as a difference value between the sensing data S1n-1 of the first sensing node.

Thereafter, an operation (ST240) of determining whether a touch event has occurred in an n-th sensing node included in the first group G1 may be performed. This step ST240 may be performed by the noise calculating unit 122 described above.

As an example, the noise calculating unit 122 is the n-th sensing node included in the m-th row and the n-th sensing node when the sum of the difference of the sensing data and the tracking change amount is greater than a preset threshold, the n-th It may be determined that a touch event has occurred in the sensing node. That is, when the following equation is satisfied, it may be determined that a touch event has occurred in the n-th sensing node.

│Smn-Smn-1 + Vt│> REF

Here, Smn is the sensing data of the nth sensing node included in the mth row, Smn-1 is the sensing data of the n-1th sensing node included in the mth row, Vt is the tracking change amount, and REF is a preset threshold. .

For example, in the case of the second sensing node included in the first row (the first group G1), it is determined that a touch event has occurred when the following equation is satisfied, and otherwise, it may be determined that the touch event has not occurred. have.

│S12-S11 + Vt│> REF

When it is determined that a touch event has not occurred in the second sensing node included in the first row (first group G1), an update step ST250 of the tracking change amount may be performed. This step ST250 may be performed through the noise calculator 122 described above, and may be omitted if necessary.

For example, when it is determined that a touch event has not occurred in the n-th sensing node included in the m-th row, the tracking change amount is set as the difference in sensing data between the n-th sensing node and the previous sensing node, or It may be updated to a value obtained by an average of a difference in sensing data from a previous sensing node for each sensing node from a previously located specific sensing node to the n-th sensing node.

For example, when it is determined that a touch event has not occurred in the second sensing node included in the first row (first group G1), the tracking change amount of the second sensing node is the second sensing node and the first sensing node. It may be updated with the difference in sensing data D11 of.

Thereafter, an operation (ST280) of determining whether a touch determination operation for the current group G1 has been completed may be performed. Since the remaining sensing nodes remain in the first group G1, a step ST240 of determining whether to touch the third sensing node may be performed thereafter.

If it is determined that the touch event has not occurred in the third sensing node included in the first row (first group G1), an update step ST250 of the tracking change amount may be performed. Accordingly, the tracking change amount of the third sensing node may be updated as an average value of the difference in sensing data of the third sensing node and the second sensing node (D12) and the difference in sensing data of the second sensing node and the first sensing node (D11). have.

However, if the number of difference values of the sensing data used when calculating the tracking change amount increases, the burden on the hardware increases. In order to alleviate this, the number of difference values of the sensing data used when calculating the tracking change amount can be appropriately adjusted.

Thereafter, when it is determined that a touch event has occurred in the fourth sensing node included in the first row (first group G1), the step of setting a touch area (ST260) may be performed. This step (ST260) may be performed through the noise calculating unit 122 described above. For example, when it is determined that a touch event has occurred in the n-th sensing node included in the m-th row, n- It may be determined that a touch event has occurred in the first sensing node and the n+1th sensing node. Therefore, in this step (ST260), when it is determined that a touch event has occurred in the n-th sensing node included in the m-th row, the n-1th sensing node, the n-th sensing node, and the n+1th sensing node are touched. It can be set as a touch area.

For example, since it is determined that a touch event has occurred in the fourth sensing node included in the first row (first group G1), the touch event is generated in the third sensing node and the fifth sensing node adjacent to the fourth sensing node. It can be determined that it has occurred. Accordingly, a third sensing node, a fourth sensing node, and a fifth sensing node may be set as a touch area in which a touch event has occurred. In particular, in the case of the third sensing node, even if it is determined that no touch event has occurred in the previous step, since the third sensing node is located adjacent to the fourth sensing node recognized as the touch region, it may be set as the touch region. Also, in the case of the fifth sensing node, even if it is determined that no touch event has occurred in a later step, since it is located adjacent to the fourth sensing node recognized as a touch region, it may be set as a touch region.

Thereafter, the step ST270 of maintaining the same amount as the previous tracking change amount without updating the tracking change amount may be performed. This step ST270 may be performed through the noise calculator 122 described above.

In addition, even when it is determined that a touch event has not occurred in the fifth sensing node included in the first row (first group G1) through the step ST240, the effect of the fourth sensing node described above. As a result, it is assumed that a touch event has occurred in the fifth sensing node, so that the tracking change amount maintenance step (S270) may be performed.

Accordingly, since the operation of determining whether to touch the current group G1 has been completed (ST280), an operation (S290) of checking the touch area may be performed.

In this step ST290, it may be determined whether each sensing node included in the first group G1 has been set as a touch area in a previous step. Thereafter, an operation ST300 of updating noise data may be performed on the sensing node determined as the touch area.

For example, when it is determined that the n-th sensing node included in the m-th row is a touch area in which a touch event has occurred, noise data of the n-th sensing node is included in the m-th row. It can be updated with the sum of the tracking change amount.

Accordingly, the noise data N13 of the third sensing node set as the touch area in the previous step may be updated to a value (N13') obtained by adding the corresponding tracking change amount to the noise data N12 of the second sensing node, and the fourth sensing The noise data N14 of the node may be updated as a value (N14') of the noise data N13 of the third sensing node and the corresponding tracking change amount, and the noise data N15 of the fifth sensing node is the fourth sensing node. It may be updated to a value (N15') obtained by adding the corresponding tracking change amount to the noise data (N14) of.

In addition, existing noise data may be maintained for a sensing node not set as a touch area.

After the above-described steps (ST290 and ST300), the step (ST310) of determining whether the touch area check for the current group G1 has been completed may be performed. When the touch area check for the corresponding group is completed, all groups An operation (ST320) of determining whether noise data has been acquired may be performed. Therefore, each step (S230, ST240, ST250, ST260, ST270, ST280, ST290, ST300, ST310) for the remaining groups (G2 to G5) may be repeatedly performed, and as noise data of all groups are acquired. Finally, total noise data as shown in FIG. 9F may be calculated.

When the calculation of the noise data for each row is completed, an operation ST330 of calculating touch data may be performed by subtracting the calculated total noise data N11 to N55 ′ from the corresponding sensing data. This step ST330 may be performed by the above-described touch calculator 123.

Through this, effective touch data in the form of FIG. 5 can be calculated, and through this, the location of the touch event and its intensity can be determined.

Meanwhile, the above-described tracking change amount updating step ST250 and the tracking change amount maintaining step S270 may be omitted to minimize the load on the hardware. In this case, the tracking change amount initially calculated for each row in the tracking change amount calculation step ST230 (average change amount of sensing data calculated for all sensing nodes) may be maintained and used without the need to separately update the tracking change amount.

Those of ordinary skill in the art to which the present invention pertains will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. The scope of the present invention is indicated by the scope of the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention. It must be interpreted.

100: touch sensor 110: touch sensing unit
120: touch control unit 121: touch driving unit
122: noise calculation unit 123: touch calculation unit
210: display panel 220: display driving circuit
221: scan driver 222: data driver
223: timing control unit 250: host

Claims (10)

a touch sensing unit including a plurality of sensing nodes consisting of j rows;
A noise calculator configured to calculate noise data for each row of the sensing node by using sensing data output from the touch sensing unit; And
A touch calculator configured to calculate touch data by subtracting the total noise data from the corresponding sensing data when the noise data for each row is calculated by the noise calculator; Including,
The noise calculation unit,
Noise data of each sensing node included in the m (1≤m≤j)-th row is set as sensing data received from the touch sensing unit, and a touch event has occurred in the n-th sensing node included in the m-th row. If it is determined, the noise data of the n-th sensing node is updated to a value obtained by adding the tracking change amount to the noise data of the n-1th sensing node included in the m-th row,
The tracking change amount is,
The difference in sensing data from the previous sensing node by at least one sensing node located before the n-th sensing node is set as an average value of the difference in sensing data from the previous sensing node for each sensing node included in the m-th row Touch sensor, characterized in that set to the average value. The method of claim 1,
The noise calculation unit,
When the sum of the tracking change amount and the difference in sensing data between the n-th sensing node and the n-th sensing node is greater than a preset threshold, it is determined that a touch event has occurred in the n-th sensing node. Touch sensor. delete The method of claim 2,
The noise calculation unit,
When the sum of the tracking change amount and the difference in sensing data between the nth sensing node and the n-1th sensing node is greater than a preset threshold, the n-1th sensing node and n+ together with the nth sensing node A touch sensor, characterized in that it is determined that a touch event has occurred in a first sensing node. The method of claim 1,
The touch sensing unit,
Including driving electrodes and sensing electrodes disposed to cross each other,
The driving electrodes,
It is formed long in the row direction and is arranged in a number along the column direction, and receives a touch driving signal,
The sensing electrodes,
A touch sensor, characterized in that it is formed elongated in the column direction, is arranged in a plurality along the row direction, and provides the sensing data to the noise calculating unit. acquiring sensing data for each sensing node from a touch sensing unit including a plurality of sensing nodes including j rows and k columns;
Calculating noise data for each row of the sensing node by using the sensing data; And
When calculation of noise data for each row is completed, calculating touch data by subtracting the calculated total noise data from the corresponding sensing data; Including,
Calculating noise data for each row of the sensing node by using the sensing data,
Noise data of each sensing node included in the m (1 ≤ m ≤ j) th row is set as sensing data received from the touch sensing unit, and the n (2 ≤ n ≤ k) th sensing included in the m th row When it is determined that a touch event has occurred in the node, the noise data of the n-th sensing node is updated to a value obtained by adding the amount of tracking change to the noise data of the n-1th sensing node included in the m-th row,
The tracking change amount is set as an average of a difference in sensing data from a previous sensing node for each sensing node included in the m-th row, or a previous sensing node for each of at least one sensing node located before the n-th sensing node A method of driving a touch sensor, characterized in that it is set as an average value of a difference in sensing data between and. The method of claim 6,
The step of calculating noise data for each row of the sensing node using the sensing data,
When the sum of the tracking change amount and the difference in sensing data between the n-th sensing node and the n-th sensing node is greater than a preset threshold, it is determined that a touch event has occurred in the n-th sensing node. How to drive the touch sensor. delete The method of claim 7,
The step of calculating noise data for each row of the sensing node using the sensing data,
When the sum of the tracking change amount and the difference in sensing data between the nth sensing node and the n-1th sensing node is greater than a preset threshold, the n-1th sensing node and n+ together with the nth sensing node A method of driving a touch sensor, characterized in that it is determined that a touch event has occurred in a first sensing node. The method of claim 6,
The touch sensing unit,
Including driving electrodes and sensing electrodes disposed to cross each other,
The driving electrodes,
It is formed long in the row direction and is arranged in a number along the column direction, and receives a touch driving signal,
The sensing electrodes,
A driving method of a touch sensor, characterized in that it is formed long in the column direction, is arranged in a plurality along the row direction, and provides the sensing data.

Images