KR20210079999A - Touch sensing device for sensing noise and display device including the same - Google Patents

Abstract

One embodiment of the present invention relates to a touch sensing technology for sensing and avoiding noise. The present invention can change a driving signal to a frequency of the least noise and block in advance the possibility that the frequency is changed in a predetermined order or randomly. The present invention includes: a driving unit transmitting a driving signal for driving a touch electrode sensing a touch or proximity of an external object; a control unit supplying the driving signal to the driving unit; a sensing unit generating a low sensed value of the touch electrode for each frame with respect to a touch region formed by the touch electrode; and a noise determination unit that determines whether there is noise in the touch area.

Description

TOUCH SENSING DEVICE FOR SENSING NOISE AND DISPLAY DEVICE INCLUDING THE SAME

This embodiment relates to a touch sensing technology for sensing noise.

A technology for recognizing an external object that approaches or touches a touch panel is called a touch sensing technology. The touch panel is placed on the same position as the display panel on a plane. Accordingly, users can input a user operation signal to the touch panel while viewing an image of the display panel. This user manipulation signal generating method provides surprising user intuition compared to the previous other user manipulation signal input methods - for example, a mouse input method or a keyboard input method.

According to these advantages, touch sensing technology is applied to various electronic devices including display panels. The touch sensing device may sense a touch or proximity of an external object with respect to the touch panel by supplying a driving signal to a driving electrode disposed on the touch panel and receiving a reaction signal formed on the sensing electrode. The touch panel creates a capacitance between the driving electrode and the sensing electrode, and a change in the capacitance may indicate a touch or proximity of the external object.

On the other hand, the touch panel may contain noise. When the external object makes contact, noise may be transmitted through the external object and the touch panel may exhibit a malfunction.

In order to sense the noise, in the related art, it is determined whether the frequency of the noise included in the response signal is similar to the frequency of the response signal, and if similar, the frequency of the driving signal is changed. When the response signal fluctuates by more than a predetermined value with respect to the reference value, it may be determined that the frequency of the noise is similar to the frequency of the response signal. Here, the reference value may be data obtained when there is no touch or proximity of an external object or when noise is not intervened.

However, this conventional method can detect noise of the same frequency as the frequency of the driving signal, but may have a problem in that it cannot detect various types of noise such as harmonic noise.

In this regard, the present embodiment intends to provide a technology for effectively sensing various types of noise generated in touch sensing.

Against this background, an object of the present embodiment is to sense noise using an average value of the difference of maximum raw sensing values between adjacent frames according to the number of touches or proximity or a geometric feature of the touch area. to provide technology.

In order to achieve the above object, an embodiment includes a driving unit that transmits a driving signal for driving a touch electrode sensing a touch or proximity of an external object; a control unit supplying the driving signal to the driving unit; a sensing unit generating a low sensed value of the touch electrode for each frame with respect to the touch region including the touch electrode; and receiving the row-sensing value, comparing the number of the touch regions between a plurality of frames, and using a representative value for the row-sensing values between the plurality of frames according to the comparison result or geometrical characteristics of the touch regions To provide a touch sensing device including a noise determining unit for determining whether there is noise in the touch area by using the .

In the device, when the number of the touch areas between the plurality of frames is the same, the noise determination unit uses an average value of the difference between the maximum row sensing values between the plurality of frames as the representative value, and generates noise in the touch area. If there is, the control unit may be controlled to change the frequency of the driving signal.

In the device, the plurality of frames may be two frames that are temporally adjacent.

In the device, the noise determining unit may determine that there is noise in the touch area when the average value is greater than a threshold value.

In the device, the noise determination unit may control the control unit to change the frequency of the driving signal if the number of the touch areas is different between the plurality of frames by using the geometrical feature, and if there is noise in the touch area have.

In the device, the plurality of touch areas are formed for each frame, and the noise determining unit determines that there is noise in the plurality of touch areas when the width or width of any one of the plurality of touch areas is within a predetermined range. can

In the device, a plurality of touch areas are formed for each frame, and the noise determining unit determines that there is noise in the plurality of touch areas when the distance between the maximum low-sensing values of the plurality of touch areas is within a certain range. can be judged.

In the device, the noise determining unit may determine that there is no noise in the plurality of touch regions when a difference between the maximum row sensing values between the plurality of frames is less than a threshold value.

Another embodiment provides a method for sensing noise by a touch sensing device, comprising: receiving a low-sensing value of the touch electrode for each frame with respect to a touch region including a touch electrode for sensing a touch or proximity of an external object; comparing the number of touch areas between a plurality of frames; and determining whether there is noise in the touch area in the comparison result, wherein the determining comprises: if the number of touch areas between the plurality of frames is the same, the difference between the maximum row sensing values between the plurality of frames Provided is a noise sensing method using an average value of , and using geometrical features of the touch regions when the number of the touch regions is different.

As described above, according to the present embodiment, various types of noise such as harmonic noise can be sensed to reduce touch misrecognition.

1 is a block diagram of a display device according to an exemplary embodiment.
2 is a diagram schematically illustrating a touch sensing system according to an embodiment.
3 is a block diagram of a touch sensing device according to an embodiment.
FIG. 4 is a diagram for explaining a noise sensing method using a difference in a maximum row sensing value between frames according to an exemplary embodiment.
5 is a first exemplary diagram for explaining a noise sensing method using a geometric feature of a touch area according to an embodiment.
6 is a second exemplary diagram for explaining a noise sensing method using geometrical features of a touch area according to an embodiment.
7 is a flowchart of an operation in which a touch sensing device senses noise according to an exemplary embodiment.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same components are given the same reference numerals as much as possible even though they are indicated on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the components from other components, and the essence, order, or order of the components are not limited by the terms. 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 another component is between each component. It should be understood that elements may be “connected,” “coupled,” or “connected.”

1 is a block diagram of a display device according to an exemplary embodiment.

Referring to FIG. 1 , the display device 100 includes a panel 110 , a data driving device 120 , a gate driving device 130 , and a touch sensing device 140 .

A plurality of data lines DL connected to the data driver 120 may be formed on the panel 110 , and a plurality of gate lines GL connected to the gate driver 130 may be formed on the panel 110 . In addition, a plurality of pixels P corresponding to intersections of the plurality of data lines DL and the plurality of gate lines GL may be defined in the panel 110 .

In each of these pixels P, a first electrode (eg, a source electrode or a drain electrode) is connected to the data line DL, a gate electrode is connected to the gate line GL, and a second electrode (eg, a second electrode) is connected to the gate line GL. , a drain electrode or a source electrode) may be formed with a transistor connected to the display electrode.

In addition, a plurality of touch electrodes TE may be further formed on the panel 110 to be spaced apart from each other. One pixel P may be located or a plurality of pixels P may be located in the region where the touch electrode TE is located.

The panel 110 may include a display panel and a touch screen panel (TSP), wherein the display panel and the touch panel may share some components with each other. For example, the plurality of touch electrodes TE may be one component of the display panel (eg, a common electrode to which a common voltage is applied) and at the same time may be one component of the touch panel (touch electrodes for sensing a touch). have. Since some components of the display panel and the touch panel are shared with each other, the panel 110 is also called an integrated panel, but the present invention is not limited thereto. In addition, although an in-cell type panel is known as a form in which some components of the display panel and the touch panel are shared with each other, this is only an example of the aforementioned panel 110 and the panel to which the present invention is applied is such an in-cell panel. It is not limited to an (In-Cell) type panel.

The data driving device 120 supplies a data signal to the data line DL to display an image in each pixel P of the panel 110 .

The data driver 120 may include at least one data driver integrated circuit, and the at least one data driver integrated circuit may include a tape automated bonding (TAB) method or a chip on glass (COG) method. It may be connected to a bonding pad of the panel 110 in a chip on glass method, or may be formed directly on the panel 110 , or may be formed by being integrated in the panel 110 in some cases. In addition, the data driving device 120 may be implemented in a chip on film (COF) method.

The gate driving device 130 sequentially supplies a scan signal to the gate line GL to turn on or off the transistor located in each pixel P.

The gate driving device 130 may be positioned on only one side of the panel 110 as shown in this figure, or divided into two and positioned on both sides of the panel 110 according to a driving method.

In addition, the gate driver 130 may include at least one gate driver integrated circuit, and the at least one gate driver integrated circuit may be formed using a tape automated bonding (TAB) method or a chip-on-glass (COG) method. It may be directly formed on the panel 110 by being connected to the bonding pad of the panel 110 or implemented in a gate in panel (GIP) type, or may be formed by being integrated in the panel 110 in some cases. In addition, the gate driving device 130 may be implemented in a chip on film (COF) method.

The touch sensing device 140 applies a driving signal to all or a part of the plurality of touch electrodes TE connected to the sensing line SL.

As shown in this figure, the touch sensing device 140 is a configuration separate from the data driving device 120 and the gate driving device 130 , and is external to the data driving device 120 and the gate driving device 130 . However, depending on the implementation method, it may be implemented as an internal configuration of another separate driver integrated circuit including at least one of the data driving device 120 and the gate driving device 130, or the data driving device ( 120) or the internal configuration of the gate driving device 130 may be implemented.

Accordingly, when the touch sensing device 140 applies the driving signal to all or a part of the plurality of touch electrodes TE, a separate driver integrated circuit including the touch sensing device 140 operates the plurality of touch electrodes TE. It can also be seen that the driving signal is applied in whole or in part. In addition, depending on the design method, the data driving device 120 or the gate driving device 130 including the touch sensing device 140 can be regarded as applying the driving signal to all or part of the plurality of touch electrodes TE. may be

The touch sensing device 140 is not limited to the implementation and design method, and if only the performance function described in this specification is the same or similar, it may be a different configuration itself or a configuration located inside or outside the other configuration. have.

Also, although one touch sensing device 140 is illustrated as being positioned on the display device 100 in this drawing, the display device 100 may include two or more touch sensing devices 140 .

Meanwhile, in order for the touch sensing device 140 to apply the driving signal to all or part of the plurality of touch electrodes TE, sensing lines SL connected to each of the plurality of touch electrodes TE are required. Accordingly, the sensing line SL, which is connected to each of the plurality of touch electrodes TE and transmits a driving signal, is connected to the panel 110 in the first direction (eg, vertical direction) or in the second direction (eg, horizontal direction). can be formed.

Meanwhile, the display device 100 may employ a capacitive touch method for recognizing proximity or touch of an object by sensing a change in capacitance through the touch electrode TE.

Such a capacitive touch method may be divided into, for example, a mutual capacitive touch method and a self-capacitive touch method.

In the mutual capacitive touch method, which is a type of the capacitive touch method, a driving signal is applied to one touch electrode (Tx electrode) and the other touch electrode (Rx electrode) coupled to the Tx electrode is sensed. In this mutual capacitive touch method, the value sensed by the Rx electrode varies according to proximity or touch of an object such as a finger or pen. In the mutual capacitance touch method, the presence or absence of touch and touch coordinates using the sensing value of the Rx electrode detect etc.

In the self-capacitance touch method, which is another type of the capacitive touch method, a driving signal is applied to one touch electrode TE and then the touch electrode TE is sensed again. In this self-capacitive touch method, the value sensed by the corresponding one touch electrode TE varies according to proximity or touch of an object such as a finger or pen. coordinates, etc. In this self-capacitive touch method, since the touch electrode TE for applying the driving signal and the touch electrode TE for sensing are the same, there is no distinction between the Tx electrode and the Rx electrode.

The display device 100 may employ one of the above-described two capacitive touch methods (mutual capacitive touch method and self-capacitive touch method). However, in this specification, for convenience of description, it is assumed that the self-capacitive touch method is employed and the embodiment will be described.

Meanwhile, the display device 100 may drive the touch electrode TE by dividing the display section and the touch section. As an example, the touch sensing device 140 of the display device 100 may not apply the driving signal to all or part of the touch electrode TE during the period in which the data signal is supplied.

Also, the display device 100 may drive the touch electrode TE without distinguishing between the display section and the touch section. As an example, the touch sensing device 140 of the display device 100 may apply a driving signal to all or a part of the touch electrode TE in a section for supplying a data signal.

2 is a diagram schematically illustrating a touch sensing system according to an embodiment.

Referring to FIG. 2 , the touch sensing system 200 may include a panel 110 and a touch sensing device 140 .

A plurality of touch electrodes TE may be disposed on the panel 110 .

The touch sensing device 140 may supply the driving signal STX to the touch electrode TE. The driving signal STX may be a voltage or current type signal, and the voltage type driving signal STX may be defined as a driving voltage. The driving signal may include one driving period including the first period and the second period.

The touch sensing device 140 receives the response signal SRX to the driving signal STX from the touch electrode TE, and demodulates the response signal SRX to touch or close the object 10 to the panel 110 . can be sensed. The response signal SRX may be a signal in the form of current or voltage.

3 is a block diagram of a touch sensing device according to an embodiment.

Referring to FIG. 3 , the touch sensing device 140 may include a driving unit 310 , a sensing unit 320 , a noise control unit 330 , a control unit 340 , and a storage unit 350 .

The driving unit 310 may supply a driving signal STX having a frequency to the touch electrode. The driving unit 310 may drive the touch electrode with a driving signal STX having a different frequency. For example, the driver 310 may receive a driving signal STX having a changed frequency from the controller 340 and drive the touch electrode with the changed frequency.

The sensing unit 320 may receive a response signal SRX to the driving signal STX from the touch electrode. The sensing unit 320 may receive a response signal SRX having a different frequency in response to the driving signal STX. For example, when the driving unit 310 drives the touch electrode at the changed frequency, the sensing unit 320 may receive the response signal SRX of the changed frequency different from the previous frequency.

The sensing unit 320 may sense a touch or proximity of an external object to the panel according to the response signal SRX. The sensing unit 320 may generate touch sensing data by demodulating the response signal SRX. The sensing unit 320 may transmit the touch sensing data to the noise determining unit 330 .

The touch sensing data may include a raw sensing value (TSEN_RAW) generated by demodulating the response signal SRX. The raw sensing value TSEN_RAW may be, for example, a time-integrated value of a current or a voltage of the response signal SRX. The raw sensing value TSEN_RAW may be used to determine whether an object is touched on the touch panel or to generate touch coordinates. For example, when the size of the raw sensing value TSEN_RAW is greater than or smaller than the reference value, it may be determined that a touch by an external object has occurred.

The sensing unit 320 may generate a low sensing value TSEN_RAW of the touch electrode with respect to the touch area including the touch electrode. The touch area may be a set of low sensing values TSEN_RAW indicated by a plurality of touch electrodes on the touch panel or an area of the set. When the touch electrodes are sensed, a raw sensing value TSEN_RAW—analog data generated by demodulating the response signal SRX— may appear for each touch electrode. The low sensing value TSEN_RAW may appear according to the arrangement of the touch electrodes of the panel. Here, a change in capacitance occurs in a touch electrode touched or adjacent to an external object. According to the change in capacitance, the low-sensing value TSEN_RAW changes, and the change in the low-sensing value TSEN_RAW is a point of touch or proximity. It may occur in several touch electrodes around the touch electrode that becomes . In the plurality of touch electrodes under the influence of touch or proximity, the low sensing value TSEN_RAW may increase or decrease compared to the touch electrodes that are not. Therefore, the touch area may be an area of the touch panel in which the low sensing values TSEN_RAW of a plurality of touch electrodes under the influence of touch or proximity appear.

Of course, the touch electrode that is most affected by the touch or proximity - the touch electrode that becomes the point of the touch or proximity - may have the most maximized raw sensing value TSEN_RAW - the maximum value or the minimum value. Hereinafter, the touch electrode that is most affected by touch or proximity may be referred to as a point touch electrode.

The sensing unit 320 may generate a low sensing value TSEN_RAW of the touch electrode for each frame with respect to the touch region including the touch electrode. The sensing unit 320 uses a first method of sensing the touch panel after all lines of the display panel are scanned in one frame and a second method of sensing the touch panel after several lines of the display panel are scanned in one frame. A sensed value (TSEN_RAW) may be generated. The sensing unit 320 may generate a low sensing value TSEN_RAW of the touch electrode in every frame in the first or second method.

The noise determining unit 330 may compare the number of touch areas between a plurality of frames. For example, the noise determining unit 330 may calculate the number of touch areas for each of two or more temporally adjacent frames, and determine whether the number of touch areas is the same or different. Here, two or more frames that are temporally adjacent may mean a frame that is continuously reproduced, such as a current frame and a previous frame or a current frame and a next frame.

In order to determine the number of touch areas, the noise determination unit 330 may use a distribution of capacitance change-low sensing value TSEN_RAW- of the touch electrode. For example, the noise determination unit 330 may determine the row sensing values TSEN_RAW connected to each other as one touch area. When the noise determination unit 330 finds a discontinuous or intermittent point where the low sensing value TSEN_RAW does not appear in one touch area, it may determine that there is a new touch area based on this.

The noise determination unit 330 may determine whether there is noise in the touch area by using a representative value of the row sensing value TSEN_RAW between a plurality of frames or by using a geometrical characteristic of the touch area according to the comparison result.

Specifically, the noise determining unit 330 uses the average value of the difference between the maximum row sensing values between the plurality of frames as the representative value when the number of the touch areas between the plurality of frames is the same, and the noise is generated in the touch area. If it is determined that there is, the controller 340 may be controlled to change the frequency of the driving signal.

For example, when the display device drives N (N is a natural number greater than or equal to 2) frames, the noise determination unit 330 may calculate the number of touch regions in the current frame and the previous frame among the first to N frames. . As a result of the noise determination unit 330 comparing the number of touch areas, if the number of touch areas is the same, the noise determination unit 330 may determine that the number of touch areas between a plurality of frames is the same. Here, the number of touch areas may be one or more, and the number of touch areas in the current frame and the previous frame may be the same.

Next, the noise determining unit 330 may calculate a maximum raw sensing value difference between two adjacent frames. The noise determining unit 330 may calculate a difference between the maximum low-sensing value of the N-1 th frame and the maximum low-sensing value of the N-th frame. In addition, the noise determining unit 330 may calculate a difference between the maximum low-sensing value of the N-2 th frame and the maximum low-sensing value of the N-1 th frame. In this way, the noise determining unit 330 may calculate the difference between the maximum row sensing values between the two adjacent frames from the first to the N frames to obtain N-1 difference values. The noise determining unit 330 may obtain an average of N-1 difference values. Accordingly, the noise determining unit 330 may calculate an average value of the difference between the maximum row sensed values between frames.

The noise determining unit 330 may use a threshold value to determine whether there is noise in the touch area from the average value. The noise determining unit 330 may determine that there is noise when the average value is greater than a threshold value. Alternatively, the noise determining unit 330 may determine that there is no noise unless the average value is greater than a threshold value.

If it is determined that there is noise, the noise determining unit 330 may generate a frequency change signal to change the frequency of the driving signal for driving the touch electrode from one touch section of the current frame or from the next frame and transmit it to the controller 340 . have.

In addition, the noise determination unit 330 uses the geometrical characteristics of the touch area when the number of the touch areas is different between a plurality of frames, and when it is determined that there is noise in the touch area, the control unit 340 changes the frequency of the driving signal. can control

For example, when the display device drives N (N is a natural number greater than or equal to 2) frames, the noise determination unit 330 may calculate the number of touch regions in the current frame and the previous frame among the first to N frames. . If the number of touch areas is different as a result of the noise determination unit 330 comparing the number of touch areas, the noise determination unit 330 may determine that the number of touch areas is different between a plurality of frames. Here, the number of touch areas may be one or more, and the number of touch areas in the current frame and the previous frame may be different.

Next, the noise determining unit 330 may derive geometric characteristics of the touch area for every frame. The noise determining unit 330 may determine the shape of the touch area or the location and distance between the touch areas as a geometric characteristic of the touch area. For example, the noise determining unit 330 may calculate the shape, location, and distance of the touch area in the current frame.

The noise determining unit 330 may use a predetermined condition to determine whether there is noise in the touch area based on the geometrical characteristics.

For example, if the width or width (horizontal or vertical) of the touch area in the current frame is within a predetermined range, the noise determination unit 330 may determine that there is noise in the touch area. The width or a certain range of the width is difficult to see as separate touches independent of each other, and may be as long as one or two touch electrodes. In general, the touch area generated by a single independent touch includes the touch electrodes around the point touch electrode and has a constant width or width. However, if noise intervenes in the touch area, it may be much shorter than the constant length. because there is

For example, when the distance (interval) between the plurality of touch areas in the current frame is within a predetermined range, the noise determining unit 330 may determine that there is noise in the touch area. A certain range of the distance is difficult to see as separate touches independent of each other, and may be as long as one or two touch electrodes. In general, a touch area generated by a single independent touch includes a peripheral touch electrode centered on the point touch electrode, so that the distance between the plurality of touch areas has a constant length. Because it could be much shorter. Here, the distance may be measured based on between the point touch electrodes of the plurality of touch areas or may be measured based on the touch electrodes located at the outermost part of the touch area.

In addition, the noise determining unit 330 may consider whether a difference between the maximum row sensing values between a plurality of frames is greater than a threshold value in order to determine the noise from the geometrical characteristics of the touch area. The noise determination unit 330 may compare the difference between the maximum row sensed value between the current frame and the previous frame with a threshold value.

When a touch or proximity is just started, the touch sensitivity is weak, and thus the width or width of the touch area may be within a predetermined range. That is, the width or width of the touch area may be as short as the length of one or two touch electrodes. When touch or proximity is just starting, noise may not be involved even if the width or width of the touch area is within a predetermined range. Accordingly, the noise determining unit 330 performs the noise determination unit 330 only on the condition that the difference between the maximum row sensing values between the plurality of frames—for example, between the current frame and the previous frame—is greater than the threshold value, the plurality of touch regions. It can be determined that there is noise in the If the difference between the maximum row sensing values between the plurality of frames is smaller than the threshold value, the noise determining unit 330 may determine that there is no noise in the plurality of touch regions.

If it is determined that there is noise, the noise determining unit 330 may generate a frequency change signal to change the frequency of the driving signal for driving the touch electrode from one touch section of the current frame or from the next frame and transmit it to the controller 340 . have.

Also, before changing the frequency of the driving signal, the noise determining unit 330 may additionally perform noise index sensing. The noise determining unit 330 may determine whether the plurality of candidate frequencies has enough noise to be used as the driving signal STX. For example, the noise determination unit 330 may calculate an average value for the difference between the maximum row sensing values TSEN_RAW between the plurality of frames also for the candidate frequencies. The noise determination unit 330 may change the frequency of the driving signal only when the average value of the candidate frequencies is smaller than the threshold value, even if the current frequency is determined to be noisy through any of the above-described methods. If the average value of the candidate frequencies is not less than the threshold value, the frequency of the driving signal may not be changed.

The control unit 340 may supply the driving signal STX to the driving unit 310 . When the control unit 340 receives the request for frequency change of the driving signal STX - the frequency change signal - from the noise determination unit 340 , the control unit 340 generates a driving signal STX having a frequency according to the request to the driving unit 310 . can be supplied with For example, the control unit 340 may generate the driving signal STX of the changed frequency and transmit it to the driving unit 310 . Thereafter, the driving unit 310 may drive the touch electrode with the driving signal STX of the changed frequency.

The controller 340 may generate a control signal CS to control the driving unit 310 and the sensing unit 320 . When the control unit 340 transmits the control signal CS to the driving unit 310 and the sensing unit 320 , the driving unit 310 and the sensing unit 320 may operate according to the control signal CS.

Data for noise sensing may be stored in the storage unit 350 . For example, a row sensed value (TSEN_RAW) of every frame, a maximum raw sensed value of every frame, or data about the number of touch regions, etc. may be stored.

FIG. 4 is a diagram for explaining a noise sensing method using a difference in a maximum raw value between frames according to an exemplary embodiment.

Referring to FIG. 4 , when the number of touches between a current frame and a previous frame is the same, the touch sensing apparatus according to an embodiment may sense noise using a difference between the maximum row sensing values between frames.

The noise determining unit of the touch sensing device may obtain a distribution of a low-sensing value 401 of a previous frame and a distribution of a low-sensing value of the current frame 402 . In this figure, the distribution of the low-sensing value 401 of the previous frame and the distribution of the low-sensing value 402 of the current frame may have the same one touch area including the first touch area I (shaded area). Since the number of touch regions between the current frame and the previous frame is the same, the noise determining unit may perform a noise sensing operation using a difference between the maximum row sensing values between frames.

The first touch area I may be an area corresponding to a plurality of touch electrodes representing a plurality of row sensing values. Each row sensed value may be represented by coordinates of an X-axis (X) and a Y-axis (Y). The first touch area (I) is (X2, Y6), (X2, Y5), (X2, Y4), (X3, Y6), (X3, Y5), (X3, Y4), (X3, Y3), It may be a region corresponding to (X4, Y5), (X4, Y4), and (X4, Y3). In the low-sensing value distribution 401 of the previous frame, the maximum low-sensing value may be 182 as (X3, Y5), which is a point at which the external object OBJ points. On the other hand, in the low-sensing value distribution 402 of the current frame, the maximum low-sensing value may be 200 as (X3, Y5), which is a point at which the external object OBJ points.

The noise determining unit may obtain a difference value −18− between the maximum low-sensing value 200 of the current frame and the maximum low-sensing value 182 of the previous frame. The noise determining unit may calculate a maximum difference between two adjacent frames for the entire frame as described above, and calculate an average value by averaging the difference.

5 is a first exemplary diagram for explaining a noise sensing method using geometrical features of a touch area according to an embodiment, and FIG. 6 is a first exemplary diagram for explaining a noise sensing method using geometrical features of a touch area according to an exemplary embodiment. This is the second example.

Referring to FIG. 5 , when the number of touches between a current frame and a previous frame is different, the touch sensing apparatus according to an embodiment may sense noise using a first geometrical feature of the current frame.

The noise determining unit of the touch sensing device may obtain a distribution of a low-sensing value of a previous frame and a distribution of a low-sensing value of the current frame 502 . In the above-described example, the distribution of the row sensing values of the previous frame may have one touch area. However, in this figure, the distribution 502 of the row sensing value of the current frame includes the 1-1 touch area I-1 (shaded area) and the 1-2 touch area I-2 (shaded area), It may have two touch areas different from the distribution of the row sensing values of the previous frame. Since the number of touch regions is different between the current frame and the previous frame, the noise determining unit may perform a noise sensing operation using the first geometrical feature.

The 1-1 touch area I-1 may be an area corresponding to (X2, Y6) and (X3, Y6). The noise determining unit may determine whether there is noise through the first geometrical feature of the 1-1 touch area I-1. For example, the noise determining unit may determine whether the width H1 of the 1-1 touch area I-1 is within a predetermined range. Preferably, the predetermined range may mean that the width of one touch area is within the length of two or less touch electrodes. In this case, the noise determining unit may determine that noise is intervening. Since the width H1 of the 1-1 touch area I-1 is within a certain range due to the length of one touch electrode, the noise determination unit determines that there is noise in the 1-1 touch area I-1. can

The 1-2-th touch area I-2 may be an area corresponding to (X2, Y4), (X3, Y4), (X3, Y3), (X4, Y4), and (X4, Y3). The noise determining unit may determine whether there is noise based on the geometrical characteristics of the first-second touch area I-2. For example, the noise determining unit may determine whether the width H2 of the 1-2 th touch area I-2 is within a predetermined range. The predetermined range means that the width of one touch area is within the length of two or less touch electrodes, and the noise determination unit may determine that noise is intervened in this case. Since the width H2 of the 1-2 touch area I-2 is within a certain range due to the length of the two touch electrodes, the noise determination unit determines that there is noise in the 1-2 touch area I-2. can

Referring to FIG. 6 , when the number of touches between the current frame and the previous frame is different, the touch sensing apparatus according to an embodiment may sense noise using the second geometrical feature of the current frame.

The noise determining unit may determine whether there is noise through the second geometrical characteristics of the 1-1 touch area I-1 and the 1-2 touch area I-2. For example, the noise determining unit may determine whether the distance D between the 1-1 touch area I-1 and the 1-2 touch area I-2 is within a predetermined range. Preferably, the predetermined range may mean that the distance between the plurality of touch areas is within the length of two or less touch electrodes. In this case, the noise determining unit may determine that noise is intervening. Since the distance D between the 1-1 touch area I-1 and the 1-2 touch area I-2 is within a certain range due to the length of one touch electrode, the noise determining unit is the 1-1 touch area It may be determined that there is noise in (I-1) or the 1-2-th touch area I-2.

In other words, in the previous frame (401 in FIG. 4 ), the first touch area (I) is (X2, Y6), (X2, Y5), (X2, Y4), (X3, Y6), (X3, Y5), (X3, Y4), (X3, Y3), (X4, Y5), (X4, Y4), and (X4, Y3) were the areas, but in the current frame, noise intervened in the first touch area (I). The first touch area I may be divided into a 1-1 touch area I-1 and a 1-2 touch area I-2. The noise determining unit of the touch sensing device may determine that one touch area is divided into a plurality of touch areas as the presence of noise by determining whether the geometrical characteristics between frames satisfy a predetermined condition. This is because if one large touch area is divided into small touch areas due to the presence of noise, the width or width of the separated touch area and the distance between the touch areas will be very short. Noise sensing using geometric features can be applied in this case.

7 is a flowchart of an operation in which a touch sensing device senses noise according to an exemplary embodiment.

Referring to FIG. 7 , according to an embodiment, the touch sensing apparatus may perform different noise sensing operations according to whether the number of touches between the current frame and the previous frame is the same.

The noise determining unit of the touch sensing device may receive a low-sensing value for a touch electrode that senses a touch or proximity of an external object (step S702). The noise determination unit may receive a row sensed value for every frame.

The noise determining unit may extract the touch area from the current frame and the previous frame, respectively (step S704).

The noise determining unit may compare the number of touch areas of the current frame and the previous frame (step S706).

If the number of touch regions in the current frame and the previous frame is the same (YES in step S706), the noise determining unit may calculate an average value of the difference between the maximum row sensing values between adjacent frames. The maximum difference between the rowsensing values may be calculated using adjacent frames for the entire frame (step S708-1). The noise determining unit may compare the average value with a threshold value (step S710-1). If the average value is greater than the threshold value (YES in step S710-1), the noise determining unit may determine that there is noise, and control the control unit and the driving unit to change the frequency of the driving signal (step S712-1). If the average value is not greater than the threshold value (NO in step S710-1), the noise determination unit may determine that there is no noise. The noise determining unit may perform noise sensing again.

If the number of touch areas in the current frame and the previous frame is different (NO in step S706), the noise determining unit may analyze the geometrical characteristics of the touch areas in the current frame (step S708-2). The noise determining unit may determine whether the geometrical feature satisfies a predetermined condition (step S710-2). Here, the predetermined condition may mean that the width or width of the touch areas and the distance between the touch areas are within a predetermined length. When a certain condition is satisfied (YES in step S710-2), the noise determining unit may determine that there is noise and control the control unit and the driving unit to change the frequency of the driving signal (step S712-2). If the predetermined condition is not satisfied (NO in step S710-2), the noise determining unit may determine that there is no noise. The noise determining unit may perform noise sensing again.

Claims (9)

a driving unit transmitting a driving signal for driving a touch electrode sensing a touch or proximity of an external object;
a control unit supplying the driving signal to the driving unit;
a sensing unit generating a low sensed value of the touch electrode for each frame with respect to the touch region formed by the touch electrode; and
Receive the row sensed value, compare the number of the touch regions between a plurality of frames, and use a representative value for the row sensed value between the plurality of frames according to the comparison result or determine the geometrical characteristics of the touch region A touch sensing device including a noise determining unit for determining whether there is noise in the touch area using the According to claim 1,
The noise determining unit may be configured to use, as the representative value, an average value of a difference between the maximum row sensing values between the plurality of frames when the number of the touch regions between the plurality of frames is the same, and if there is noise in the touch area, the driving A touch sensing device for controlling the control unit to change the frequency of the signal. 3. The method of claim 2,
The plurality of frames are two frames that are temporally adjacent to each other. 3. The method of claim 2,
The noise determining unit may be configured to determine that there is noise in the touch area when the average value is greater than a threshold value. According to claim 1,
The noise determining unit may control the control unit to change the frequency of the driving signal if the number of the touch areas is different between the plurality of frames by using the geometrical feature and if there is noise in the touch area. 6. The method of claim 5,
The touch area is formed in plurality for each frame,
The noise determination unit may be configured to determine that there is noise in the plurality of touch areas when the width or width of any one of the plurality of touch areas is within a predetermined range. 6. The method of claim 5,
The touch area is formed in plurality for each frame,
The noise determining unit may be configured to determine that there is noise in the plurality of touch areas when a distance between the maximum raw sensing values of the plurality of touch areas is within a predetermined range. 8. The method of claim 7,
The noise determining unit may be configured to determine that there is no noise in the plurality of touch regions when a difference between the maximum raw sensing values between the plurality of frames is less than a threshold value. A method for sensing noise by a touch sensing device, the method comprising:
receiving a low-sensing value of the touch electrode for each frame with respect to a touch region including a touch electrode for sensing a touch or proximity of an external object;
comparing the number of touch areas between a plurality of frames; and
determining whether there is noise in the touch area in the comparison result,
In the determining, if the number of touch areas between the plurality of frames is the same, an average value of the difference in the maximum row sensing value between the plurality of frames is used, and if the number of touch areas is different, the geometric shape of the touch area is used. A noise sensing method using features.

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