KR102390164B1 - Touch sensing method, touch sensing circuit, and touch display device - Google Patents

Abstract

The present embodiments relate to a touch sensing method, a touch sensing circuit, and a touch display device, in which a plurality of pseudo touch periods are defined within a touch period for touch sensing, and a multi-frequency driving method is performed in the plurality of pseudo touch periods. To a touch sensing method, a touch sensing circuit, and a touch display device for sensing the presence or absence of a touch or a touch position by outputting a touch driving signal for performing touch driving with a touch panel. According to the present embodiments, it is possible to output the touch driving signal at an accurate timing in the multi-frequency driving method.

Description

Touch sensing method, touch sensing circuit and touch display device

The present embodiments relate to a touch sensing method, a touch sensing circuit, and a touch display device.

As the information society develops, the demand for display devices for displaying images is increasing in various forms, and in recent years, liquid crystal display devices (LCDs), plasma display devices (PDPs), organic Various display devices such as an organic light emitting display device (OLED) are being used.

Among these display devices, there is a touch display device capable of providing a touch-based input method that allows a user to easily and intuitively and conveniently input information or commands by breaking away from a conventional input method such as a button, a keyboard, and a mouse. .

In order for such a touch display device to provide a touch-based input method, it is necessary to detect the presence or absence of a user's touch and to accurately detect touch coordinates (touch position).

To this end, based on a change in capacitance between touch electrodes or capacitance between a touch electrode and a pointer such as a finger through a plurality of touch electrodes disposed as a touch sensor on a touch panel (touch screen panel), the presence or absence of touch and touch coordinates, etc. A capacitive touch method for detecting .

On the other hand, an electronic device such as a touch display device having a touch sensing function must satisfy a condition that the level of electromagnetic interference (EMI, hereinafter referred to as "EMI") must be below a certain level.

However, the conventional touch display device has a problem in that the EMI level is considerably increased due to a touch driving signal for touch sensing.

In particular, when the touch driving signal applied to the touch electrode for touch sensing is a pulse-type signal having a predetermined frequency, the EMI effect may be further increased.

Due to the effect of EMI, the system stability of the touch display device is lowered, and the touch sensing performance is lowered by affecting the sensing voltage obtained during touch sensing, or other voltages required for the display are also affected, thereby lowering the display performance. can be

Against this background, the present embodiments may provide a touch sensing method, a touch sensing circuit, and a touch display device capable of improving an EMI (Electro Magnetic Interference) level.

The present embodiments may provide a touch sensing method, a touch sensing circuit, and a touch display device capable of performing touch driving in a multi-frequency driving method enabling EMI improvement.

The present embodiments may provide a touch sensing method, a touch sensing circuit, and a touch display device capable of improving touch sensing accuracy during touch driving in a multi-frequency driving method enabling EMI improvement.

In one aspect, the touch display device according to the present exemplary embodiments transmits a pulse-type touch driving signal to the touch panel according to a touch panel on which a plurality of touch electrodes are disposed, and a touch synchronization signal defining a touch period for touch sensing. and may include a touch sensing circuit for sensing the presence or absence of a touch or a touch position.

The touch sensing circuit of the touch display device may generate a pseudo touch synchronization signal defining a plurality of pseudo touch periods within the touch period.

Such a touch sensing circuit may output a touch driving signal generated during a plurality of pseudo touch periods according to the pseudo touch synchronization signal.

In such a touch display device, a frequency of a touch driving signal output in at least one pseudo touch period among the plurality of pseudo touch periods may be different from a frequency of a touch driving signal output in another pseudo touch period.

In the touch display device, in each of at least one of the plurality of pseudo touch periods, touch driving signals having different frequencies may be output.

In each of the at least one pseudo-touch period in the touch display device, the two or more touch driving signals having different frequencies may be applied to the touch electrodes in different regions of the touch panel.

In such a touch display device, the pseudo touch synchronization signal may define a rest period in which the touch driving signal is not output before and after each of the plurality of pseudo touch periods together with the plurality of pseudo touch periods.

In such a touch display device, at least one pseudo-touch period among the plurality of pseudo-touch periods may have a different time length from other pseudo-touch periods.

In such a touch display device, at least one touch period may be included in one display frame period.

In such a touch display device, a touch period may be performed alternately with a display period in which the touch panel is driven in a display mode for displaying an image.

In such a touch display device, the touch period may proceed at least partially overlapping with the display period for driving the touch panel in a display mode for displaying an image.

In another aspect, the touch sensing method according to the present embodiments may provide a touch sensing method of a touch display device including a touch panel on which a plurality of touch electrodes are disposed.

The touch sensing method includes a pseudo touch synchronization signal generating step of generating, according to a touch synchronization signal defining a touch period for touch sensing, a pseudo touch synchronization signal defining a plurality of pseudo touch periods within the touch period; A touch driving signal generating step of generating a pulse-type touch driving signal in the plurality of pseudo-touch periods according to a pseudo-touch synchronization signal, and outputting the touch driving signal to the touch panel according to the touch synchronization signal and determining whether there is a touch or not. It may include a touch sensing step of sensing a position.

In another aspect, the touch sensing circuit according to the present embodiments may be included in a touch display device including a touch panel on which a plurality of touch electrodes are disposed.

The touch sensing circuit generates a pseudo touch synchronization signal defining a plurality of pseudo touch periods within the touch period according to a touch synchronization signal defining a touch period for touch sensing, and according to the pseudo touch synchronization signal A touch controller generating at least one touch driving control signal, a touch driving signal generating unit generating a pulse-type touch driving signal in the plurality of pseudo touch periods according to the at least one touch driving control signal, and the touch synchronization signal Accordingly, a touch driving unit for outputting the touch driving signal to the touch panel may be included.

According to the present exemplary embodiments described above, it is possible to provide a touch sensing method, a touch sensing circuit, and a touch display device capable of improving an EMI (Electro Magnetic Interference) level.

According to the present embodiments, it is possible to provide a touch sensing method, a touch sensing circuit, and a touch display device capable of performing touch driving in a multi-frequency driving method enabling EMI improvement.

According to the present embodiments, it is possible to provide a touch sensing method, a touch sensing circuit, and a touch display device capable of improving touch sensing accuracy during touch driving of a multi-frequency driving method that enables EMI improvement.

1 is a schematic system configuration diagram of a touch display device according to embodiments.
2 and 3 are diagrams illustrating a display section and a touch section of a touch display device according to embodiments.
4 is a diagram for explaining a ground voltage modulation for time-free driving in a touch display device according to embodiments of the present invention.
5 is a schematic configuration diagram of a touch circuit according to example embodiments.
6 illustrates a connection structure between a touch circuit and a plurality of touch electrodes according to example embodiments.
7 is a view for explaining a method of driving a multiplexer of a touch display device according to embodiments.
8 shows waveforms of touch driving signals according to embodiments.
9 is a schematic configuration diagram of a touch circuit according to example embodiments.
10 to 13 show waveforms of a pseudo touch synchronization signal and a touch driving signal according to embodiments.
14 is a flowchart illustrating a touch sensing method of a touch display device according to example embodiments.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in 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 may 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 elements from other elements, and the essence, order, order, or number of the elements are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but other components may be interposed between each component. It should be understood that each component may be “interposed” or “connected”, “coupled” or “connected” through another component.

1 is a schematic system configuration diagram of a touch display device 100 according to the present exemplary embodiments.

In the touch display device 100 according to the present exemplary embodiments, a plurality of data lines DL and a plurality of gate lines GL are disposed, and are defined by a plurality of data lines DL and a plurality of gate lines GL. The display panel 110 includes a plurality of sub-pixels SP arranged therein.

Also, the touch display device 100 may include a touch panel 120 on which a plurality of touch electrodes TE serving as a touch sensor for touch sensing are disposed.

The touch panel 120 may be manufactured separately from the display panel 110 and bonded to the display panel 110 , or may be embedded in the display panel 110 .

When the touch panel 120 is embedded in the display panel 110 , the touch panel 120 may be viewed as an aggregate of a plurality of touch electrodes TE and a plurality of touch lines TL.

When the plurality of touch electrodes TE are embedded in the display panel 110 , the plurality of touch electrodes TE may be disposed as an in-cell type or an on-cell type. , may be manufactured together when the display panel 110 is manufactured.

Hereinafter, for convenience of description, it is assumed that the touch panel 120 is embedded in the display panel 110 , and the display panel 110 and the touch panel 120 are not separately distinguished.

The touch display device 100 according to the present exemplary embodiments has two driving operations: display driving for image display and touch driving for touch sensing.

The touch display device 100 according to the present exemplary embodiments includes a source driving circuit SDC for driving a plurality of data lines DL in order to drive the display panel 110 during a display period in which display driving is performed. It may include a source driving circuit (GDC) and a gate driving circuit (GDC) for driving the plurality of gate lines GL.

In addition, the touch display device 100 supplies various control signals DCS and GCS to the source driving circuit SDC and the gate driving circuit GDC to control the source driving circuit SDC and the gate driving circuit GDC. It may further include a controller CONT to control.

The controller CONT starts scanning according to the timing implemented in each display frame, and converts the input image data input from the outside to match the data signal format used by the source driving circuit SDC, and converts the converted image data ( Data) and control the data drive at an appropriate time according to the scan.

Such a controller may be a timing controller used in a conventional display technology or a control device that further performs other control functions including a timing controller.

Also, the controller may transmit a touch synchronization signal Tsync for defining a touch period during which touch driving for touch sensing of the touch panel 120 is performed to the touch circuit TC.

Referring to FIG. 1 , the touch display device 100 drives the touch panel 120 during a touch period, receives a signal from the touch panel 120 , and performs touch sensing and pen touch sensing based on the received signal. It may include a touch circuit TC.

The touch circuit TC generates a touch driving signal (TDS) for driving the plurality of touch electrodes TE in a defined touch period according to the touch synchronization signal Tsync received from the controller CONT. Thus, it is possible to output to the touch electrodes TE.

In embodiments according to the present invention, the touch controller TP may be built-in to the controller CONT (or a timing controller).

The touch circuit TC receives a touch driving circuit (TDC) for driving the plurality of touch electrodes TE and the touch electrodes TE to which the touch driving signal TDS is applied during the touch period. It may include a touch controller (TP), etc. for determining the presence or absence of a touch and/or a touch position based on the received signal.

The touch driver TDC may supply the touch driving signal TDS to the plurality of touch electrodes TE to drive the plurality of touch electrodes TE.

The touch driver TDC may receive a touch sensing signal TSS from each touch electrode TE to which the touch driving signal TDS is supplied.

The touch driver TDC transmits the received touch sensing signal TSS or the signal-processed sensing data to the touch controller TP.

The touch controller TP may execute a touch algorithm by using the touch sensing signal TSS or sensed data, and may determine the presence or absence of a touch and/or a touch position through this.

Although not shown, the touch display device 100 may include a touch driving signal generator (not shown) that generates the touch driving signal TDS. The touch driving signal generator may be inside or outside the touch driving unit TDC.

The touch driving signal generator may be inside or outside the touch controller TP. In some cases, the touch driving signal generator may be implemented as a separate power controller integrated circuit.

In particular, in the present embodiments, the touch controller TP may generate a pseudo touch synchronization signal for defining a plurality of pseudo touch periods included in the touch period according to the touch synchronization signal Tsync received from the controller. .

Here, each of the plurality of pseudo-touch periods may be temporally separated within the touch period.

In addition, the touch driving signal generator may generate the touch driving signal TDS during a plurality of pseudo touch periods according to the pseudo touch synchronization signal and output the generated touch driving signal TDS to the touch driving unit TDC.

In this case, the touch driving signal generator may generate a frequency of the touch driving signal TDS in at least one pseudo touch period among the plurality of pseudo touch periods to be different from the frequency of the touch driving signal TDS in other pseudo touch periods.

Also, the touch driving signal generator may generate a plurality of touch driving signals TDS having different frequencies in at least one of the plurality of pseudo touch periods.

The touch controller TP according to the present embodiments is based on self-capacitance that detects the presence or absence of a touch and/or the location of the touch by detecting a change in self-capacitance between each touch electrode TE and the pointer. of the touch sensing method may be employed.

Also, in the touch display device 100 according to the present exemplary embodiments, a driving electrode (also referred to as a touch driving electrode or a transmission (Tx) electrode) and a sensing electrode (touch sensing) in which a plurality of touch electrodes TE are electrically separated from each other electrode or receiving (Rx) electrode), by applying a touch driving signal (TDS) to the driving electrode, and receiving the touch sensing signal (TSS) from the sensing electrode, the mutual-capacitance between the driving electrode and the sensing electrode ( A mutual-capacitance-based touch sensing method for detecting the presence or absence of a touch and/or the location of a touch based on a change in Mutual-Capacitance may be employed.

Meanwhile, the above-mentioned source driving circuit (SDC), gate driving circuit (GDC), touch driving unit (TDC), and touch controller (TP) are functionally classified and may be implemented separately, and in some cases, the source driving circuit ( SDC). Two or more of the gate driving circuit GDC, the touch driving unit TDC, and the touch controller TP may be integrated and implemented.

In the present exemplary embodiments, one touch electrode TE may be larger than the size of one sub-pixel SP. That is, one touch electrode TE may have a size corresponding to or larger than the size of the area occupied by the plurality of subpixels SP.

For example, one touch electrode TE (unit touch electrode) may have a size several to several hundred times larger than that of one sub-pixel SP.

The ratio between the size of the touch electrode and the size of the sub-pixel may be adjusted by comprehensively considering the touch sensing efficiency and performance, or the influence of the display due to the touch sensing.

For example, the touch display device 100 may block a plurality of common electrodes (Vcom electrodes) used when driving a display and use them as a plurality of touch electrodes TE.

The touch display panel 110 may be various types of panels such as a liquid crystal display panel and an organic light emitting display panel. For example, when the display panel 110 is a liquid crystal display panel, the touch display device 100 may use a common voltage (Vcom) is applied to block the pixel electrode and a plurality of common electrodes forming an electric field, so that they can be used as a plurality of touch electrodes TE.

As another example, when the touch display panel 110 is an organic light emitting display panel, the touch display device 100 includes the first electrode, the organic light emitting layer and the second electrode constituting an organic light emitting diode (OLED). A plurality of touch electrodes TE may be formed on a touch sensor metal layer positioned on an encapsulation layer having an encapsulation function.

Hereinafter, for convenience of description, it is assumed that the plurality of touch electrodes TE are used as touch driving electrodes (touch sensors) when driving a touch and are used as common electrodes (Vcom electrodes) when driving a display. do.

2 and 3 are diagrams illustrating a display section and a touch section of a touch display device according to embodiments.

The touch display device 100 according to the embodiments may perform a driving operation in a time division driving method and/or a time free driving method.

Referring to FIG. 2 , when the touch display device 100 operates in a time division driving method, the touch display device 100 performs a time division operation of a display driving for providing an image display function and a touch driving for providing a touch sensing function. to be performed in the display period DS and the touch period TS, respectively.

In this case, the timing of the display period DS and the touch period TS may be controlled by the touch synchronization signal TSYNC. That is, the touch synchronization signal Tsync may be used as a signal for defining the display period DS together with the touch period TS.

During the display period DS, a common voltage that is a DC voltage may be applied to the plurality of touch electrodes TE.

Here, the common voltage may be a pixel voltage applied to a pixel electrode in each sub-pixel and a voltage forming an electric field.

During the touch period TS, the touch driving signal TDS may be applied to all or part of the plurality of touch electrodes TE.

In this case, the touch driving signal TDS or a signal corresponding thereto may be applied to all or part of the data lines DL. The touch driving signal TDS or a signal corresponding thereto may be further applied to all or part of the gate lines GL.

The touch driving signal TDS may be a pulse-type signal with a variable voltage level.

In addition, a method of time-dividing one display frame period into a display period DS and a touch period TS may be further classified into a V-sensing method and an H-sensing method.

In the case of the V-sensing method, one display frame period is time-divided into one display period DS and one or more touch periods TS.

During one display period DS, the touch display device 100 performs display driving for one display frame.

During one or more touch periods TS, the touch display device 100 senses the presence or absence of a touch or a touch position in one display frame area.

In the case of the H-sensing method, one display frame period is time-divided into two or more display periods DS and two or more touch periods TS.

During the two or more display periods DS, the touch display device 100 performs display driving for one display frame.

During the two or more touch periods TS, the touch display device 100 senses the presence or absence of a touch or a touch position in one display frame area.

Meanwhile, referring to FIG. 3 , when the touch display device 100 operates in a time free driving method, display driving for providing an image display function and touch driving for providing a touch sensing function are performed. can be done simultaneously. This time-free driving method is also referred to as a simultaneous driving method.

As the touch display device 100 becomes a large screen and a high resolution, the time required for the display period and the touch period is increasing. Accordingly, when the time-divided display period and the touch period are separately distinguished, one display frame period may be exceeded.

However, in the time-free driving method, since the display period and the touch period may overlap, the time constraint between the display period and the touch period may be reduced.

Although the display period and the touch period are exemplified as the same period in FIG. 3 , the driving time point or the driving end point of the display period and the touch period may be different from each other.

That is, at least a portion of the display period in which the display panel 110 is driven in the display mode and the touch period of the touch panel 120 may overlap in time.

When the touch display device 100 is driven in a time-free driving method, for example, the touch driving circuit TDC outputs sensing data including values corresponding to differences in sensing signals corresponding to two touch electrodes. can be configured.

That is, the touch circuit TC performs a first touch line TL1 and a second touch among the plurality of touch lines TL during a display driving period in which the data voltages VDATA are applied to the plurality of data lines DL. A touch presence or touch coordinates may be acquired based on sensing data including a value corresponding to a difference between the first sensing signal TSS1 and the second sensing signal TSS2 received from the line TL2 .

This method may be referred to as a differential sensing method.

Meanwhile, the touch driving signal TDS may be a signal for driving the touch electrodes TE for touch sensing and a common voltage that allows the touch electrodes TE to serve as a common electrode for driving a display.

For example, the touch driving signal TDS may be a data voltage VDATA supplied to each of two or more subpixels SP overlapping each touch electrode TE and a common voltage forming a capacitance.

That is, the touch driving signal TDS is a voltage forming capacitance with the data voltage VDATA supplied to each of the two or more sub-pixels SP overlapping the first touch electrode TE1 and the second touch electrode TE2 ) may be a data voltage VDATA supplied to each of the two or more sub-pixels SP overlapping each other and a voltage forming a capacitance.

When the touch display device 100 operates in a time-free driving method, the pixel voltage applied to the pixel electrode in each sub-pixel and the common voltage forming the electric field are not a DC voltage, but a pulse signal with a variable voltage level. there is.

In addition, when the touch display device 100 is driven in a time-free driving method, the plurality of touch electrodes TE may be a plurality of blocked common electrodes, and the touch driving signal TDS may also be viewed as a common voltage. can

In this case, the touch synchronization signal Tsync may be used as a signal for defining the touch period regardless of the display period.

4 is a diagram for explaining a ground voltage modulation for time-free driving in a touch display device according to embodiments of the present invention.

In the touch display device 100 , the touch driving signal TDS for time-free driving may be a voltage corresponding to the ground voltage GND_M to which the display panel 110 is grounded.

The ground voltage GND_M to which the display panel 110 is grounded may be a signal whose voltage level changes.

The touch driving signal TDS may correspond to the ground voltage GND_M to which the display panel 110 is grounded in frequency and phase.

The ground voltage GND_M to which the display panel 110 is grounded is a DC voltage to which the touch controller TP sensing the presence or absence of a touch or touch coordinates or a controller CONT for display driving control is grounded during the display driving period. It may be a signal modulated based on the ground voltage GND of .

In relation to the above-described ground modulation and touch driving signal TDS, the display panel 110 is grounded to the modulated ground voltage M_GND, so that the touch electrodes TE corresponding to the common electrodes disposed on the display panel 110 are grounded. ), even when the touch driving signal TDS in the form of a DC voltage is applied, the touch driving signal TDS is shaken by the modulated ground voltage M_GND, so that the touch driving signal TDS is modulated with the modulated ground voltage M_GND. It becomes a signal whose voltage level changes identically or similarly to .

Meanwhile, the touch driving signal TDS for time-free driving may be a voltage corresponding to the ground voltage GND_M to which the display panel 110 is grounded.

5 is a schematic configuration diagram of a touch circuit according to embodiments, and FIG. 6 shows a connection structure between the touch circuit and a plurality of touch electrodes according to the embodiments.

1 , the touch circuit TC includes a touch controller TP and a touch driver TDC. Also, as shown in FIG. 5 , the touch controller TP may include a touch driving control signal generating unit PWMD and a touch sensing unit TSU.

The touch driving control signal generator PWMD receives a touch synchronization signal Tsync defining a touch period for driving the display panel 110 for touch sensing from the controller CONT of the touch display device.

The touch driving control signal generator PWMD generates the touch driving control signal PWM during the touch period according to the received touch synchronization signal Tsync, and outputs the generated touch driving control signal PWM to the touch driving signal generator TPIC.

The touch driving signal generator TPIC generates a pulse-type touch driving signal TDS according to the touch driving control signal PWM and outputs it to the touch driving unit TDC.

In this case, the touch driving signal generating unit TPIC may generate by varying the waveform (eg, frequency) of the touch driving signal TDS according to the waveform (eg, frequency or duty ratio) of the touch driving control signal PWM. there is.

Referring to FIG. 6 , the touch driving unit TDC receives the touch driving signal TDS from the touch driving signal generating unit TPIC, and transmits the received touch driving signal TDS to a plurality of touch electrodes through the touch electrode line TL. The output is made to the touch electrodes TE to drive the plurality of touch electrodes TE.

When driving the plurality of touch electrodes TE, the touch driver TDC may sequentially drive one or two or more of the plurality of touch electrodes TE, or use all of the plurality of touch electrodes TE. They can even run together.

In addition, the touch driving unit TDC receives the touch sensing signal TSS from each touch electrode TE to which the touch driving signal TDS is supplied, and touches the received touch sensing signal TSS or the sensed data processed by the touch sensing signal TSS. It is transmitted to the sensing unit (TSU).

Here, the touch sensing signal TSS is a signal whose waveform varies according to a change in capacitance of each of the plurality of touch electrodes.

The touch sensing unit TSU may execute a touch algorithm by using the touch sensing signal TSS or sensing data, and may detect the presence or absence of a touch and/or a touch position through this.

Meanwhile, during the touch period, when the touch driving signal TDS is applied to one or more of the touch electrodes TE, the touch electrode TE to which the touch driving signal TDS is applied is connected to the data line DL. A parasitic capacitance Cp may be formed with each of the gate line GL and the other touch electrodes TE to which the touch driving signal TDS is not applied.

As described above, the parasitic capacitance generated during the touch period acts as a load during touch sensing and may be a major factor in reducing sensing accuracy.

Accordingly, in the touch display device 100 according to the present exemplary embodiments, when at least one of the plurality of touch electrodes TE is sequentially driven during a touch period, the parasitic capacitance Cp acting as a load during touch sensing ) can be performed to prevent or reduce the occurrence of load free driving.

In the load-free driving, when the touch driving signal TDS is applied to the at least one touch electrode TE during the touch period, the plurality of data lines DL, the plurality of gate lines GL, and the remaining touch electrodes TE are operated. The load-free driving signal LFDS may be applied in whole or in part.

When the load-free driving signal LFDS corresponds to the touch driving signal TDS, the load-free driving signal LFDS has the same frequency as that of the touch driving signal TDS, and the phase and the touch driving signal TDS. It may have the same phase or may have the same amplitude as the amplitude of the touch driving signal TDS.

Accordingly, a potential difference is generated between the touch electrode TE to which the touch driving signal TDS is applied and the data line DL, the gate line GL, and the touch electrode TE to which the load-free driving signal LFDS is applied. Otherwise, the parasitic capacitance Cp can be prevented from being formed.

Here, the load-free driving signal LFDS may be the same or substantially the same signal as the touch driving signal TDS, and may remove or reduce parasitic capacitance between the touch electrode TE, which is a touch sensing target, and another electrode. If there is, it may be a signal different from or similar to the touch driving signal TDS.

Meanwhile, the touch display device 100 controls at least one of the plurality of touch electrodes TE by using the touch driving signal TDS having a pulse type of a single frequency (eg, several tens of KHz to several hundred KHz) during the touch period. When sequentially driven, EMI (Electro Magnetic Interference) may occur in a harmonic frequency component according to a change in the voltage level of the touch driving signal TDS.

In particular, the touch display device 100 controls at least one of the plurality of touch electrodes TE by using the touch driving signal TDS having a pulse type of a single frequency (eg, several tens of KHz to several hundred KHz) during the touch period. Sequential driving, and at this time, when load-free driving of at least one of the other touch electrode TE, the data line DL, and the gate line GL is further performed, EMI caused by the touch driving signal TDS is reduced. It may become more severe.

Accordingly, the touch display device 100 according to the embodiments may provide a multi-frequency driving method in order to reduce the EMI phenomenon caused by the touch driving signal TDS.

According to the multi-frequency driving method in which the frequency of the touch driving signal TDS for driving the touch electrode TE is two or more, the frequency of the touch driving signal TDS output from the touch circuit TC is variable. can

According to the multi-frequency driving, as the frequency of the touch driving signal TDS output from the touch circuit TC varies, an EMI dispersion phenomenon occurs, so that the EMI phenomenon caused by the touch driving signal TDS can be alleviated.

7 is a diagram for explaining a multiplexer driving method of the touch display device 100 according to the present exemplary embodiment.

When the touch driver TDC simultaneously senses a plurality of touch electrodes TE, the touch driver TDC must be configured to simultaneously process the touch sensing signal TSS received from the touch electrode TE. Accordingly, there is a problem in that the circuit configuration of the touch driver TDC becomes very complicated.

On the other hand, when the touch driver TDC individually senses the plurality of touch electrodes TE, there is a problem in that the driving time for all the touch electrodes TE is greatly increased. That is, the time required for the touch period increases.

Accordingly, the touch driver TDC may include a multiplexer circuit including a plurality of multiplexers to simultaneously sense two or more touch electrodes among the plurality of touch electrodes TE.

Referring to FIG. 6 , the multiplexer circuit assumes that eight multiplexers (MUX A - MUX H) are configured.

Each of the eight multiplexers (MUX A to MUX H) has four channels (1, 2, 3, 4). (1, 2, 3, 4 are the channel numbers of each MUX)

Referring to FIG. 6 , as an example, the plurality of touch electrodes TE may include a plurality of groups (Group 1, 2, 3, 4) can be grouped.

Group 1 710 may be touch electrodes sensed by the touch driving signal TDS output through channel 1 of each multiplexer (touch electrodes sensed in the MUX 1 driving period).

Group 2 720 may be touch electrodes sensed by the touch driving signal TDS output through channel 2 of each multiplexer (touch electrodes sensed in the MUX 2 driving period).

The group 3 730 may be touch electrodes sensed by the touch driving signal TDS output through the channel 3 of each multiplexer (touch electrodes sensed in the MUX 3 driving period).

Group 4 740 may be touch electrodes sensed by the touch driving signal TDS output through channel 4 of each multiplexer (touch electrodes sensed in the MUX 4 driving period).

That is, the plurality of groups 710 to 740 may be viewed as a set of touch electrodes TE that are selected and sensed simultaneously by a plurality of multiplexers MUX A - MUX H.

When the touch electrodes TE are sensed, other channels of each multiplexer may output a Load Free Driving (LFD) driving signal corresponding to a signal similar to, identical to, or substantially identical to the touch driving signal TDS. there is.

Since it has been described above that the touch driver TDC includes eight multiplexers MUX A - MUX H, the touch driver TDC can sense eight touch electrodes TE at the same time.

However, in some cases, the touch driver TDC may be configured to simultaneously drive eight or more touch electrodes TE by electrically connecting two or more touch electrodes to each channel 1, 2, 3, 4 of the multiplexer. .

In addition, one or more of the plurality of multiplexers (MUX A, MUX B, MUX C, MUX D, MUX E, MUX F, MUX G, MUX H) may be driven separately.

8 shows waveforms of touch driving signals according to embodiments.

FIG. 8 shows an example of a waveform of the touch driving signal TDS generated by the touch circuit TC of FIG. 5 .

When the touch display device 100 uses a multi-frequency driving method to reduce EMI caused by the touch driving signal TDS, a method of varying the frequency of the touch driving signal TDS with time may be used. .

To this end, the touch driving signal generator TPIC varies the touch driving control signal PWM and transmits it to the touch driving signal generator TPIC, and the touch driving signal generator TPIC transmits the touch driving control signal PWM. Accordingly, the frequency of the touch driving signal TDS may be varied and generated.

Here, the touch driving signal generator TPIC may vary the frequency of the touch driving signal TDS at a specific timing according to the touch driving control signal PWM.

The touch driving unit TDC may receive the touch driving signal TDS and output the received touch driving signal TDS to the plurality of touch electrodes TE.

In this case, the touch driving unit TDC may output the received touch driving signal TDS through the plurality of multiplexers MUX A to MUX H.

Accordingly, as shown in FIG. 8 , when the frequency of the touch driving signal TDS is temporally changed, the touch driving signal TDS of the same frequency may be supplied to the plurality of touch electrodes TE at the same time point, and at different time points. In , touch driving signals TDS of different frequencies may be supplied to the plurality of touch electrodes TE.

As described above, when each of the plurality of groups 710 to 740 is a set of touch electrodes TE sensed at the same time, touch driving signals TDS of the same frequency are applied to the touch electrodes in each group 710 to 740 . ) is supplied, touch driving signals TDS of different frequencies may be supplied to the touch electrodes of different groups.

In FIG. 8 , for convenience of understanding, touch driving signals TDS output through each of a plurality of multiplexers MUX A to MUX H are TDSa, TDSb, TDSc, . separated by . And the touch driving signals TDS output from the plurality of multiplexers MUX A to MUX H to each channel 1, 2, 3, 4, that is, the touch driving signals output to each of the plurality of groups 710 to 740 (TDS) again (TDSa1, TDSa2, TDSa3), (TDSb1, TDSb2, TDSB3), (TDSc1, TDSc2, TDSc3)… and marked separately.

Referring to FIG. 8 , the frequency of the touch driving signal TDS generated by the touch circuit TC of FIG. 5 varies with time. Only the same touch driving signal TDS may be supplied.

For example, the driving signals TDSa1, TDSb1, TDSc1, ...) output to channel 1 of each multiplexer may be the same touch driving signal (TDSa1 = TDSb1 = TDSc1 = ...).

In addition, the driving signals TDSa2, TDSb2, TDSc2, ...) output to channel 2 of each multiplexer may be the same touch driving signals (TDSa2 = TDSb2 = TDSc2 = ...). Also, the driving signals output to channel 3 of each multiplexer The TDSa3, TDSb3, TDSc3, ... may also be the same touch driving signal (TDSa3 = TDSb3 = TDSc3 = ...).

Here, that the driving signals are identical may mean that the phase, amplitude, and all other signal characteristics between the touch driving signals TDS are completely identical or substantially identical. "Substantially equal" means that two values are considered equal, even if they are actually different, if the difference is within a predefined tolerance margin. For example, the allowable margin may be ㅁ20%, ㅁ10%, ㅁ5%, ㅁ1%, and the like.

Meanwhile, in order for the touch display device 100 to reduce the EMI phenomenon caused by the touch driving signal TDS, in the multi-frequency driving method, a method in which a plurality of touch driving signals TDS having different frequencies are used together may be used. . Also, a method of varying the frequency of each of the plurality of touch driving signals TDS having different frequencies may be used.

However, in the touch circuit TC of FIG. 5 , it is difficult to apply a method in which a plurality of touch driving signals TDS having different frequencies are used together.

Even when the touch driving signal generating unit TPIC is configured to generate a plurality of touch driving signals TDS of different frequencies and transmit them to the touch driving unit TDC, a plurality of touch driving signals ( TDS) This is because it is difficult to specify a time point at which each frequency is varied.

As shown in FIG. 8 , when the frequency of the touch driving signal TDS is changed based on a specific time point, a plurality of touch driving signals TDS of different frequencies can be supplied to each group 710 to 740 . The channel change timing of the multiplexers (MUX A to MUX H) of the

If there is a difference between the time when the frequency of the touch driving signal TDS is changed and the time when the channels of the plurality of multiplexers are changed, there is a problem in that the accuracy of touch sensing is lowered.

In addition, it is difficult to stabilize a voltage state that changes rapidly in each touch electrode TE.

9 is a schematic configuration diagram of a touch circuit according to example embodiments.

Like the touch circuit TC of FIG. 5 , the touch circuit TC of FIG. 9 also includes a touch controller TP and a touch driver TDC. In addition, the touch controller TP may include a touch driving control signal generating unit PWMD and a touch sensing unit TSU.

However, unlike the touch circuit TC of FIG. 9 , the touch controller TP further includes a pseudo touch synchronization signal generator PTSG.

In addition, the touch synchronization signal Tsync transmitted from the controller CONT is not transmitted to the touch driving control signal generation unit PWMD, but is transmitted to the pseudo touch synchronization signal generation unit PTSG.

The pseudo touch synchronization signal generator PTSG generates a pseudo touch synchronization signal PTsync for defining a plurality of pseudo touch periods PTS within the touch period TS defined by the touch synchronization signal Tsync. Then, the generated pseudo touch synchronization signal PTsync is transmitted to the touch driving control signal generator PWMD.

Here, the pseudo touch synchronization signal PTsync is a signal for temporally dividing the touch periods TS so that a plurality of pseudo touch periods PTS can be included in the touch period TS.

Accordingly, the touch driving control signal generating unit PWMD generates a touch driving control signal PWM in a plurality of pseudo touch periods PTS within the touch period TS according to the pseudo touch synchronization signal PTsync instead of the touch synchronization signal Tsync. is generated and output to the touch driving signal generating unit TPIC.

In embodiments, the pseudo touch synchronization signal PTsync is a touch period TS defined by the touch synchronization signal Tsync irrespective of the time-free driving method and the time division driving method (including both the V-sensing method and the H-sensing method). ), a plurality of pseudo-touch periods (PTS) may be defined.

The touch driving signal generator TPIC generates at least one pulse-type touch driving signal TDS according to the touch driving control signal PWM, and outputs the generated touch driving signal TDS to the touch driving unit TDC.

The touch driving control signal generator PWMD prevents the frequency of the driving signal TDS from being changed during the pseudo touch period PTS by preventing the touch driving control signal PWM from being changed during the pseudo touch period PTS. can

However, the touch driving control signal generator PWMD is configured to generate the touch driving control signal PWM from one pseudo touch period PTS to the next pseudo touch period PTS temporally divided according to the pseudo touch synchronization signal PTsync. The waveform can be varied.

Accordingly, the driving signal TDS may vary the frequency of the touch driving signal TDS between temporally divided pseudo-touch periods PTS.

To this end, the pseudo touch synchronization signal PTsync may also define a rest period for stably varying the frequency of the touch driving signal TDS.

Here, the idle period is a period during which the touch driving signal TDS is not output before and after each of the plurality of pseudo touch periods PTS.

In addition, before the idle period is changed from one temporally divided pseudo-touch period PTS to another pseudo-touch period PTS, by providing a temporal margin for a plurality of multiplexers of the touch driver TDC to change channels. , it is possible to improve the touch sensing accuracy.

That is, the pseudo touch synchronization signal generator PTSG generates the pseudo touch synchronization signal PTsync, and the timing at which the frequency of the at least one touch drive signal TDS generated by the touch drive signal generator TPIC can be varied. can be set.

Accordingly, the at least one touch driving signal TDS may be generated in synchronization with the pseudo touch period PTS defined by the pseudo touch synchronization signal PTsync.

Accordingly, the frequency of the at least one touch driving signal TDS does not vary during the plurality of pseudo touch periods PTS within the touch period TS, so that the frequency may be stabilized.

Also, when a plurality of touch driving signals PTS of different frequencies are generated, the timing at which the touch driving signals PTS of different frequencies are generated may be synchronized.

Meanwhile, the touch driving signal generating unit TPIC uses the pseudo touch synchronization signal PTsync to accurately distinguish the pseudo touch period PTS in which the touch driving signal TDS is output and the idle period in which the touch driving signal TDS is not output. can receive more.

That is, the touch driving signal generator TPIC generates the touch driving signal PTS without distinction between the pseudo touch period PTS and the idle period, but receives the pseudo touch synchronization signal PTsync and generates only during the pseudo touch period PTS. The touch driving signal PTS may be output to the touch driving unit TDC.

10 to 13 show waveforms of a pseudo touch synchronization signal and a touch driving signal according to embodiments.

Hereinafter, waveforms of the pseudo touch synchronization signal and the touch driving signal of FIGS. 10 to 13 will be described with reference to FIG. 9 .

10 to 13 , the synchronization signal Tsync has two voltage levels (high level or low level) in the same manner, and defines the touch period TS as a period of a first level (here, a low level as an example) assume that

As described above, the pseudo synchronization signal PTsync may be driven during the touch period TS, which is the first level period of the synchronization signal Tsync.

Here, it is assumed that the pseudo sync signal PTsync also has two voltage levels (a high level or a low level), and the touch period TS is defined as a period that is a first level (here, a low level as an example).

A plurality of periods in which the pseudo synchronization signal PTsync has the first level within one touch period TS are time-divided and may be included, and each period in which the pseudo synchronization signal PTsync has the first level is a pseudo touch period. It is defined as (PTS1, PTS2, PTS3, ...).

That is, the plurality of pseudo touch periods PTS1, PTS2, PTS3, ... are temporally separated within the touch period TS.

The touch driving control signal PWM generated by the touch driving control signal generator PWMD has a waveform in the rest period between the plurality of pseudo touch periods PTS1, PTS2, PTS3, ... according to the pseudo touch synchronization signal PTsync. can be variable.

The touch driving signal generator TPIC generates at least one pulse-type touch driving signal TDS according to the touch driving control signal PWM, and outputs the generated touch driving signal TDS to the touch driving unit TDC.

However, the touch driving signal generator TPIC does not output the touch driving signal TDS during the idle period defined by the pseudo touch synchronization signal PTsync.

FIG. 10 illustrates a case in which the frequency of the touch driving signal TDS varies with time, as in FIG. 8 .

Accordingly, only the same touch driving signal TDS may be supplied to the plurality of multiplexers MUX A to MUX H at the same time.

Accordingly, the driving signals (TDSa1, TDSb1, TDSc1, …) output to channel 1 of each multiplexer may be the same touch driving signal (TDSa1 = TDSb1 = TDSc1 = …), and driving signals output to channel 2 of each multiplexer The ones TDSa2, TDSb2, TDSc2, ... may also have the same touch driving signal (TDSa2 = TDSb2 = TDSc2 = ...). Also, the driving signals TDSa3, TDSb3, TDSc3, ...) output to the channel 3 of each multiplexer may be the same touch driving signals (TDSa3 = TDSb3 = TDSc3 = ...).

However, as for the touch driving signal TDS in FIG. 8 , it is difficult to specify the timing at which the frequency is changed, and accordingly, each channel 1, 2, 3, 4) There was a problem in that it was difficult to accurately set the switching timing.

In contrast, in FIG. 10 , although the touch driving signal TDS varies with time as in FIG. 8 , after the idle period defined by the pseudo touch synchronization signal PTsync, the pseudo touch periods PTS1, PTS2, PTS3, ... ), a touch driving signal TDS having a variable frequency is output.

In this case, the frequency of the touch driving signal TDS is not changed in the plurality of pseudo-touch periods PTS1, PTS2, PTS3, ....

Therefore, in the pseudo-touch periods PTS1, PTS2, PTS3, .

In addition, the plurality of multiplexers MUX A to MUX H of the touch driver TDC switches channels 1, 2, 3, and 4 in the plurality of multiplexers MUX A to MUX H during the idle period.

Accordingly, the idle period may help to stabilize a voltage state that rapidly changes in the touch electrode TE to which the touch driving signal TDS is supplied.

Since the frequency of the touch driving signal TDS of FIG. 10 varies according to time, the touch driving signal generating unit TPIC may output one touch driving signal TDS to the touch driving unit TDC. However, the touch driving signal generating unit TPIC may output a plurality of identical touch driving signals TDS to the touch driving unit TDC.

11 illustrates a case in which a plurality of touch driving signals TDS are output with different frequencies.

In this case, since the plurality of touch driving signals TDS have different frequencies to reduce EMI, the frequencies of the plurality of touch driving signals TDS may not vary with time.

In addition, each of the plurality of touch driving signals TDS may be supplied to the touch electrode TE through a corresponding multiplexer among the plurality of multiplexers MUX A to MUX H of the touch driving unit TDC.

Accordingly, driving signals ((TDSa1, TDSa2, TDSa3, …), (TDSb1, TDSb2, TDSb3, …), (TDSc1, TDSc2, TDSc3, .

11 , although the frequency of the plurality of touch driving signals TDS having different frequencies does not change with time, the plurality of multiplexers MUX A to MUX H transmits the touch driving signals TDS. In order to change the touch electrode TE to be supplied, it is necessary to switch each channel 1 , 2 , 3 , and 4 .

In addition, it is not preferable that the pulse-type touch driving signal TDS be continuously supplied at the timing when the multiplexers MUX A to MUX H switch the channels 1, 2, 3, and 4 .

However, as shown in FIG. 11 , in embodiments, since the plurality of touch driving signals TDS are not output during the idle period, the plurality of multiplexers MUX A to MUX H is configured for each channel 1, 2, and 3, 4) can be converted stably.

12 illustrates a case in which a plurality of touch driving signals TDS having different frequencies vary according to time.

Since the frequencies of the plurality of touch driving signals TDS having different frequencies may vary according to time, when the touch driving signals TDS shown in FIG. 12 are used, the EMI phenomenon may be further reduced.

However, as shown in FIG. 12 , when a plurality of touch driving signals TDS having different frequencies are generated with varying frequencies over time, when the frequency change timing of each touch driving signal TDS is different from each other, , the touch sensing accuracy may be greatly reduced.

However, since the plurality of touch driving signals TDS according to the embodiments may be generated in synchronization with the pseudo touch synchronization signal PTsync, the plurality of touch electrodes (TDS) stably irrespective of the number or frequency of the touch driving signals TDS. TE) can be selected to drive.

That is, the touch sensing accuracy can be improved.

13 illustrates a case in which the period of the pseudo touch synchronization signal PTsync is varied.

10 to 12 , the pseudo touch synchronization signal PTsync has a fixed frequency and a duty ratio.

However, in some cases, the waveform of the pseudo touch synchronization signal PTsync may also be set to vary.

For example, in FIG. 13 , the pseudo touch synchronization signal PTsync has a waveform in which the lengths of the plurality of pseudo touch periods PTS1, PTS2, PTS3, ... are variable while the length of the idle period is kept the same.

Also in FIG. 13 , it is assumed that the frequency of the touch driving signal TDS varies with time.

As described above, when the frequency of the touch driving signal TDS is changed according to time, the pseudo touch synchronization signal PTsync corresponds to the touch driving signal TDS included in each of the pseudo touch periods PTS1, PTS2, PTS3, ... The length of the pseudo touch periods PTS1, PTS2, PTS3, ... may be adjusted so that the number of pulses N is the same.

That is, the lengths of the plurality of pseudo touch periods PTS1, PTS2, PTS3, ... defined within the touch period TS by the pseudo touch synchronization signal PTsync may be adjusted to be different from each other.

The method for varying the frequency of the touch driving signal TDS for multi-frequency driving may include the following examples.

The frequency of the touch driving signal TDS may be varied while sequentially selecting available frequencies included in the predetermined available frequency list.

In order to further increase the variability of the frequency, the available frequencies included in the predetermined available frequency list are selected in a predetermined order, and while the selection order is changed according to a certain rule, the You can also change the frequency.

In order to further increase frequency variability, a touch drive signal (TDS) is randomly selected according to a shuffle process (process of randomly selecting a frequency) of available frequencies included in a predetermined available frequency list. ) can be varied. That is, the frequency of the touch driving signal TDS may be changed according to shuffle processing of the available frequency list.

In order to further increase the variability of the frequency, as another example of a method for varying the frequency of the touch driving signal TDS, the frequency of the touch driving signal TDS is determined completely randomly without a predetermined available frequency list. You can also change the frequency. That is, the frequency of the touch driving signal TDS may be changed randomly.

In this case, the frequency variation range (minimum value to maximum value) may be determined, and an algorithm for generating random information such as a hash function may be used to determine the random frequency.

14 is a flowchart illustrating a touch sensing method of a touch display device according to example embodiments.

Referring to FIG. 14 , in the touch sensing method of the touch display device 100 including the touch panel 120 on which a plurality of touch electrodes are disposed, first, the touch circuit TC defines a touch period TS for touch sensing. According to the touch synchronization signal Tsync, a pseudo touch synchronization signal PTsync defining a plurality of pseudo touch periods within the touch period is generated (S1410).

Here, the touch synchronization signal Tsync may be received from the controller CONT of the touch display device 100 .

In addition, the touch period TS defined by the touch synchronization signal Tsync is temporally divided by the display period DS for providing the image display function of the touch display device 100 and the time division driving method, or a time-free driving method At least some periods may overlap.

In addition, when the touch period TS and the display period DS are temporally separated, the V-sensing method and the H-sensing method according to a method of time-dividing one display frame period into the display period DS and the touch period TS It can be classified in different ways.

In this case, the touch synchronization signal Tsync may be used to distinguish the display period DS from the touch period TS.

In embodiments, the pseudo touch synchronization signal PTsync is a touch period TS defined by the touch synchronization signal Tsync irrespective of the time-free driving method and the time division driving method (including both the V-sensing method and the H-sensing method). ), a plurality of pseudo-touch periods (PTS) may be defined.

Also, a rest period may be defined between the plurality of pseudo touch periods (PTS).

Meanwhile, the touch circuit TC generates a pulse-type touch driving signal PTS in a plurality of pseudo touch periods PTS according to the pseudo touch synchronization signal PTsync ( S1420 ).

In this case, the touch circuit TC fixes the frequency of the touch driving signal PTS not to vary in each of the plurality of pseudo touch periods PTS, while in the idle period between the plurality of pseudo touch periods PTS, the touch driving signal ( PTS) frequency can be varied.

However, the touch circuit TC does not output the touch driving signal PTS during the idle period.

In addition, the touch circuit TC outputs the touch driving signal TDS to at least one of the plurality of touch electrodes of the touch panel 120 according to the touch synchronization signal Tsync to drive the output (S1430).

When driving the plurality of touch electrodes TE, the touch circuit TC may sequentially drive one or two or more of the plurality of touch electrodes TE, or all of the plurality of touch electrodes TE together. can also be driven

In addition, the touch circuit TC receives the touch sensing signal TSS from each touch electrode TE to which the touch driving signal TDS is supplied, and senses the presence or absence of a touch or a touch position with respect to the plurality of touch electrodes (S1440). .

Accordingly, in the touch sensing method of the touch display device according to the embodiments, the frequency of the touch driving signal TDS is varied in synchronization with the pseudo touch sync signal PTsync, or a plurality of touch driving signals TDS having different frequencies are applied. generated and supplied to the touch panel 120 , it is possible to improve the level of Electro Magnetic Interference (EMI).

In addition, it is possible to improve touch sensing accuracy during touch driving using a multi-frequency driving method that enables EMI improvement.

The above description and the accompanying drawings are merely illustrative of the technical spirit of the present invention, and those of ordinary skill in the art to which the present invention pertains can combine configurations within a range that does not depart from the essential characteristics of the present invention. , various modifications and variations such as separation, substitution and alteration will be possible. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100: touch display device 110: display panel
120: touch panel GDC: gate driving circuit
SDC: source driving circuit CONT: controller
TC: touch circuit TDC: touch driver
TP: Touch controller PWMD: Touch drive control signal generator
PTSG: pseudo touch sync signal generator TSU: touch sensing unit
TPIC: touch driving signal generator

Claims (11)

a touch panel on which a plurality of touch electrodes are disposed; and
A touch sensing circuit for outputting a pulse-type touch driving signal to the touch panel according to a touch synchronization signal defining a touch period for touch sensing and sensing the presence or absence of a touch or a touch position;
The touch sensing circuit,
generating a pseudo-touch synchronization signal defining a plurality of pseudo-touch periods within the touch period and one or more idle periods existing between different pseudo-touch periods;
outputting a touch driving signal generated in a plurality of pseudo-touch periods according to the pseudo-touch synchronization signal;
The touch sensing circuit includes a multiplexer having two or more channels,
The multiplexer outputs the touch driving signal to at least one of the two or more channels,
In the idle period, the multiplexer changes a channel for outputting the touch driving signal. According to claim 1,
A frequency of a touch driving signal output in at least one pseudo touch period among the plurality of pseudo touch periods is different from a frequency of a touch driving signal output in another pseudo touch period. According to claim 1,
In each of the at least one pseudo touch period among the plurality of pseudo touch periods, touch driving signals of two or more different frequencies are output. 4. The method of claim 3,
In each of the at least one pseudo-touch period,
The at least two touch driving signals of different frequencies are applied to touch electrodes in different regions of the touch panel. According to claim 1,
The pseudo touch synchronization signal is
The touch display device defines the idle period in which the touch driving signal is not output before and after each of the plurality of pseudo touch periods together with the plurality of pseudo touch periods. 6. The method of claim 5,
At least one pseudo touch period of the plurality of pseudo touch periods has a different length of time from other pseudo touch periods. According to claim 1,
The touch period is
A touch display device including at least one in one display frame period. According to claim 1,
The touch period is
A touch display device that alternates with a display period in which the touch panel is driven in a display mode for displaying an image. According to claim 1,
The touch period is
A touch display device in which at least a portion overlaps with a display period in which the touch panel is driven in a display mode for displaying an image. In the touch sensing method of a touch display device including a touch panel on which a plurality of touch electrodes are disposed,
According to a touch synchronization signal defining a touch period for touch sensing, a plurality of pseudo touch periods within the touch period and a pseudo touch synchronization signal defining one or more idle periods existing between different pseudo touch periods are generated. generating a pseudo touch synchronization signal;
a touch driving signal generating step of generating a pulse-type touch driving signal in the plurality of pseudo-touch periods according to the pseudo-touch synchronization signal; and
A touch sensing step in which a multiplexer having two or more channels according to the touch synchronization signal outputs the touch driving signal in at least one channel of the two or more channels to the touch panel and senses the presence or absence of a touch or a touch position;
A touch sensing method in which a channel for outputting the touch driving signal in the multiplexer is changed during the idle period. A touch sensing circuit included in a touch display device including a touch panel on which a plurality of touch electrodes are disposed, the touch sensing circuit comprising:
According to a touch synchronization signal defining a touch period for touch sensing, a plurality of pseudo touch periods within the touch period and a pseudo touch synchronization signal defining one or more idle periods existing between different pseudo touch periods are generated. a touch controller generating at least one touch driving control signal according to the pseudo touch synchronization signal;
a touch driving signal generator configured to generate a pulse-type touch driving signal in the plurality of pseudo-touch periods according to the at least one touch driving control signal; and
a touch driving unit for outputting the touch driving signal to the touch panel according to the touch synchronization signal;
The touch controller is
detecting a change in capacitance of each of the plurality of touch electrodes through the touch driving unit to sense the presence or absence of a touch or a touch position;
The touch sensing circuit includes a multiplexer having two or more channels,
The multiplexer outputs the touch driving signal to at least one of the two or more channels,
A touch sensing circuit in which a channel for outputting the touch driving signal in the multiplexer is changed during the idle period.

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