KR102628564B1 - Touch circuit and touch display device - Google Patents

Abstract

Embodiments of the present invention relate to a touch circuit and a touch display device, and more specifically, to a sensing unit, a first switch connected between a touch panel and a first input terminal of the sensing unit to transmit a touch sensing signal, and , a second switch for transmitting a common voltage connected between the touch panel and the second input terminal of the sensing unit, and a noise detection circuit connected to the first or second input terminal of the sensing unit to detect noise inflow, A switching circuit that controls the operation of the first switch and the second switch according to the noise detection signal output from the noise detection circuit, is connected to the first input terminal or the second input terminal of the sensing unit, and changes the level of the internal voltage according to the change. A touch circuit and a touch display device including a discharge circuit that discharges noise can be provided.

Description

Touch circuit and touch display device {TOUCH CIRCUIT AND TOUCH DISPLAY DEVICE}

Embodiments of the present invention relate to a touch 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 panels (PDPs), organic Various display devices such as organic light emitting display devices (OLED) are being used.

These display devices break away from typical input methods such as buttons, keyboards, and mice, and provide a touch-based input method that allows users to easily and intuitively and conveniently input information or commands.

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

For this purpose, the presence or absence of a touch is determined based on the change in capacitance between the touch electrodes or the capacitance between the touch electrode and a pointer such as a finger through a plurality of touch electrodes (e.g., horizontal electrodes, vertical electrodes) formed on the touch display device. A capacitance touch method that detects touch coordinates, etc. is widely used.

At this time, during the operation of the touch display device, if external noise or abnormal signals, such as walkie-talkie signals, flow into the touch sensing circuit, abnormalities may occur in the touch sensing circuit, reducing the accuracy of touch sensing or causing damage to certain blocks of the display panel. A problem of blurring (block dim) occurs.

Embodiments of the present invention can provide a touch circuit and a touch display device that prevent blurring caused by noise flowing into a touch panel.

Additionally, embodiments of the present invention can provide a touch circuit and a touch display device that discharge noise flowing into a touch panel.

Additionally, embodiments of the present invention can provide a touch circuit and a touch display device that can detect and discharge noise when it enters the touch panel.

In one aspect, embodiments of the present invention include a first switch connected between a sensing unit and a first input terminal of the touch panel and the sensing unit to transmit a touch sensing signal, and a second input terminal of the touch panel and the sensing unit. A second switch that transmits a common voltage connected to, a noise detection circuit that is connected to the first or second input terminal of the sensing unit to detect noise inflow, and a noise detection signal output from the noise detection circuit. A touch circuit including a switching circuit that controls the operation of the first switch and the second switch, and a discharge circuit that is connected to the first or second input terminal of the sensing unit and discharges noise according to a change in the level of the internal voltage. can be provided.

In one aspect, the first switch and the second switch may provide a touch circuit that is a multiplexer.

In one aspect, the noise detection circuit includes a resistor string connected in series between a reference voltage and ground, a first comparator that compares a touch sensing signal or a common voltage and a first normal voltage distributed by the resistor string, and a touch sensing signal or A touch circuit including a second comparator that compares a common voltage and a second normal voltage distributed by a resistor string, and an OR gate that outputs a noise detection signal according to the outputs of the first comparator and the second comparator can be provided. .

In one aspect, when the touch sensing signal or common voltage falls within the range between the first normal voltage and the second normal voltage, a touch circuit may be provided that determines that noise has not entered the touch sensing signal or common voltage. .

In one aspect, the switching circuit includes a first and a second XOR gate that receives a control signal from the second switch as an input and outputs a second switching signal to the second switch.

In one aspect, the switching circuit may provide a touch circuit that turns off the first switch and the second switch when the noise detection signal of the noise detection circuit is at a high level.

In one aspect, the discharge circuit may provide a touch circuit including a first discharge circuit for discharging negative charge noise and a second discharge circuit for discharging positive charge noise.

In one aspect, the first discharge circuit includes a first discharge transistor whose drain terminal and source terminal are connected between the first input terminal or the second input terminal of the sensing unit and ground, and a first node between a high level voltage and ground. 1 A touch circuit including an odd number of inverters connected in series between gate terminals of a discharge transistor can be provided.

In one aspect, the second discharge circuit includes a second discharge transistor whose drain terminal and source terminal are connected between the first or second input terminal of the sensing unit and ground, and a second node between a low level voltage and ground. A touch circuit including an even number of inverters connected in series between the gate terminals of two discharge transistors can be provided.

In another aspect, embodiments of the present invention apply a common voltage to a touch panel in which a plurality of data lines and a plurality of gate lines are arranged and a plurality of subpixels are arranged, and a plurality of touch electrodes constituting the touch panel, A device comprising a touch circuit that senses a touch through a touch sensing signal transmitted from a plurality of touch electrodes, wherein the touch circuit is connected between a sensing unit and a first input terminal of the touch panel and the sensing unit to transmit the touch sensing signal. 1 switch, a second switch that transmits a common voltage connected between the touch panel and the second input terminal of the sensing unit, and a noise detection device that is connected to the first or second input terminal of the sensing unit to detect noise inflow A circuit, a switching circuit that controls the operation of the first switch and the second switch according to the noise detection signal output from the noise detection circuit, connected to the first input terminal or the second input terminal of the sensing unit, and the level of the internal voltage Depending on the change, a touch display device including a discharge circuit that discharges noise can be provided.

According to embodiments of the present invention, it is possible to provide a touch circuit and a touch display device that prevent blurring caused by noise flowing into a touch panel.

Additionally, according to embodiments of the present invention, a touch circuit and a touch display device that discharge noise flowing into a touch panel can be provided.

Additionally, according to embodiments of the present invention, when noise flows into a touch panel, it is possible to provide a touch circuit and a touch display device that can detect and discharge noise.

1 is a block diagram showing the system configuration of a touch display device according to embodiments of the present invention.
FIG. 2 is a diagram illustrating an example of touch driving and sensing operations in a touch display device according to embodiments of the present invention.
FIG. 3 is a diagram illustrating an example of a touch panel built into a display panel in a touch display device according to embodiments of the present invention.
Figure 4 is a diagram showing a conventional touch sensing circuit in a touch display device.
Figure 5 is a diagram showing an operation mode of a touch display device according to embodiments of the present invention.
FIG. 6 is a diagram illustrating an example of a display error occurring in a display panel when a noise signal such as a walkie-talkie signal is introduced into the touch display device.
Figure 7 is a diagram showing a signal timing diagram in which noise, such as a radio signal, is introduced into a touch display device.
Figures 8 and 9 are diagrams showing circuit operations when a display error occurs in a touch display device due to noise such as a radio signal.
Figure 10 is a block diagram showing the configuration of a touch circuit in a touch display device according to embodiments of the present invention.
Figure 11 is a diagram showing a noise detection circuit for determining noise inflow in a touch display device according to embodiments of the present invention.
Figure 12 is a diagram showing a switching circuit for controlling a signal supplied to a sensing unit in a touch display device according to embodiments of the present invention.
Figure 13 is a diagram showing a discharge circuit that discharges noise flowing into the display panel in a touch display device according to embodiments of the present invention.
Figure 14 is a diagram showing a touch circuit for discharging noise introduced into the display panel in a touch display device according to embodiments of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to the exemplary drawings. In adding reference numerals to components in each drawing, the same components may have the same reference numerals as much as possible even if they are shown in different drawings. Additionally, when 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. When “comprises,” “has,” “consists of,” etc. mentioned in the specification are used, other parts may be added unless “only” is used. When a component is expressed in the singular, it can also include the plural, unless specifically stated otherwise.

Additionally, when describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the components are not limited by the term.

In the description of the positional relationship of components, when two or more components are described as being “connected,” “coupled,” or “connected,” the two or more components are directly “connected,” “coupled,” or “connected.” ", but it should be understood that two or more components and other components may be further "interposed" and "connected," "combined," or "connected." Here, other components may be included in one or more of two or more components that are “connected,” “coupled,” or “connected” to each other.

In the description of temporal flow relationships related to components, operation methods, production methods, etc., for example, temporal precedence relationships such as “after”, “after”, “after”, “before”, etc. Or, when a sequential relationship is described, non-continuous cases may be included unless “immediately” or “directly” is used.

On the other hand, when a numerical value or corresponding information (e.g., level, etc.) for a component is mentioned, even if there is no separate explicit description, the numerical value or corresponding information is related to various factors (e.g., process factors, internal or external shocks, It can be interpreted as including the error range that may occur due to noise, etc.).

1 is a block diagram showing the system configuration of a touch display device according to embodiments of the present invention.

Referring to FIG. 1, the touch display device 100 according to embodiments of the present invention is a display device that can provide both a display function for displaying an image on a screen and a touch sensing function.

In order to provide a display function for displaying an image on a screen, the touch display device 100 according to embodiments of the present invention has a plurality of data lines (DL) and a plurality of gate lines (GL), and a plurality of sub A display panel 110 on which pixels (subpixels) are arranged, a data driving circuit 120 driving a plurality of data lines DL, a gate driving circuit 130 driving a plurality of gate lines GL, and It includes a timing controller 140 that controls the data driving circuit 120 and the gate driving circuit 130.

The timing controller 140 controls the data driving circuit 120 and the gate driving circuit 130 by supplying various control signals to the data driving circuit 120 and the gate driving circuit 130.

The timing controller 140 starts scanning according to the timing implemented in each frame, converts the image data input from the outside to fit the data signal format used in the data driving circuit 120, and outputs the converted image data. and controls data operation at an appropriate time according to the scan signal.

The data driving circuit 120 drives the plurality of data lines DL by supplying a data voltage to the plurality of data lines DL.

The gate driving circuit 130 sequentially drives the plurality of gate lines GL by sequentially supplying scan signals to the plurality of gate lines GL.

The gate driving circuit 130 sequentially supplies scan signals of on voltage or off voltage to the plurality of gate lines GL under the control of the timing controller 140.

When a specific gate line (GL) is opened by the gate driving circuit 130, the data driving circuit 120 converts the image data received from the timing controller 140 into an analog data voltage to generate a plurality of data lines (DL). supplied by

Here, the case where the data driving circuit 120 is located only on one side (e.g., upper or lower side) of the display panel 110 is shown. However, depending on the driving method, panel design method, etc., both sides (e.g., upper or lower side) of the display panel 110 are shown. : It can be located both on the upper and lower sides.

Likewise, the case where the gate driving circuit 130 is located only on one side (e.g., left or right) of the display panel 110 is shown here, but depending on the driving method, panel design method, etc., the display panel 110 It may be located on both sides (e.g. left and right).

The timing controller 140 described above generates various timing signals including a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a data enable signal (DE), and a clock signal (CLK) along with the input image data. Receive from outside (e.g. host system).

The timing controller 140 converts image data input from the outside to suit the format of the data signal used in the data driving circuit 120, outputs the converted image data, and operates the data driving circuit 120 and the gate driving circuit. In order to control the circuit 130, timing signals such as a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a data enable signal (DE), and a clock signal (CLK) are input, and various control signals are generated. It is output to the data driving circuit 120 and the gate driving circuit 130.

For example, the timing controller 140 uses a gate start pulse, a gate shift clock, a gate output enable signal, etc. to control the gate driving circuit 130. Outputs various gate control signals including.

Here, the gate start pulse controls the start timing at which the gate driving circuit 130 operates. The gate shift clock is a clock signal commonly input to the gate driving circuit 130, and controls the shift timing of the scan signal. The gate output enable signal specifies timing information of the gate driving circuit 130.

In addition, the timing controller 140 includes a source start pulse, source sampling clock, and source output enable signal to control the data driving circuit 120. Outputs various data control signals.

Here, the source start pulse controls the timing of starting data sampling of the data driving circuit 120. The source sampling clock is a clock signal that controls the sampling timing of data in the data driving circuit 120. The source output enable signal controls the output timing of the data driving circuit 120.

Each data driving circuit 120 is connected to a bonding pad of the display panel 110 using a tape automated bonding (TAB) method or a chip on glass (COG) method. It may be placed directly on the panel 110, and in some cases, may be integrated and placed on the display panel 110.

Additionally, each data driving circuit 120 may be implemented using a chip on film (COF) method that is mounted on the film 121 connected to the display panel 110.

Each data driving circuit 120 may include a shift register, a latch circuit, a digital to analog converter (DAC), an output buffer, etc.

Each gate driving circuit 130 is connected to the bonding pad of the display panel 110 using a tape automated bonding (TAB) method or a chip-on-glass (COG) method, or is implemented as a GIP (Gate In Panel) type. It may be placed directly on the display panel 110, or in some cases, may be integrated and placed on the display panel 110.

Additionally, each gate driving circuit 130 may be implemented using a chip-on-film (COF) method that is mounted on the film 131 connected to the display panel 110.

Each gate driving circuit 130 may include a shift register, a level shifter, etc.

The touch display device 100 mounts at least one source printed circuit board (SPCB: 160), control components, and various electrical devices required for circuit connection to the data driving circuit 120. It may include a control printed circuit board (CPCB) 170.

The data driving circuit 120 may be mounted on at least one source printed circuit board 160 or the film 121 on which the data driving circuit 120 is mounted may be connected.

The control printed circuit board 170 includes a timing controller 140 that controls the operations of the data driving circuit 120 and the gate driving circuit 130, a display panel 110, a data driving circuit 120, and a gate driving circuit. A power management integrated circuit (PMIC: 150) that supplies various voltages or currents or controls various voltages or currents to be supplied may be mounted at (130).

At least one source printed circuit board 160 and the control printed circuit board 170 may be connected in a circuit manner through at least one connecting member 180.

Here, the connection member 180 may be a flexible printed circuit (FPC), a flexible flat cable (FFC), or the like.

At least one source printed circuit board 160 and the control printed circuit board 170 may be integrated and implemented as one printed circuit board.

The touch display device 100 according to embodiments of the present invention is of various types such as a liquid crystal display device, an organic light emitting display device, and a plasma display device. It could be a device.

For example, when the touch display device 100 is an organic light emitting display device, the touch display device 100 includes a first electrode, an organic light emitting layer, a second electrode, and a first electrode constituting an organic light emitting diode (OLED). It may include an encapsulation layer located on the upper part and having a sealing function, and a touch sensor metal layer located on the upper part, and a plurality of touch electrodes (TE) are formed on the touch sensor metal layer. It may be.

In addition, the touch display device 100 according to embodiments of the present invention is formed in an area where one gate line and one data line intersect to form a touch electrode on a thin film transistor (TFT) substrate constituting a subpixel. It may also be applied to display devices of various structures.

FIG. 2 is a diagram illustrating an example of touch driving and sensing operations in a touch display device according to embodiments of the present invention.

Referring to FIG. 2, the touch display device 100 according to embodiments of the present invention includes a plurality of common electrodes (CE: Common Electrode) that serve as touch sensors (touch electrodes) to provide a touch sensing function. , a touch circuit 190 that senses touch by sequentially driving a plurality of common electrodes (CE).

The touch circuit 190 sequentially drives and senses a plurality of common electrodes (CE) to detect the presence or absence of a touch and calculate touch coordinates.

More specifically, the touch circuit 190 selects at least one of the plurality of common electrodes (CEs) as a common electrode (CEs) to be sensed, and sends a touch driving signal (TDS) to the selected common electrodes (CEs). ) is supplied. Then, based on the touch sensing signal (TSS) received for each selected common electrode (CEs) and unselected common electrode (CEo), the change in capacitance (or change in voltage or change in charge) for each common electrode (CE) etc.), the presence or absence of a touch can be detected or touch coordinates can be calculated.

The touch circuit 190 includes, for example, a touch controller 192 that controls the generation of signals related to touch sensing and performs processes for detecting the presence or absence of touch and calculating touch coordinates, and drives the touch on the display panel 110. It includes a touch sensing circuit 194 that supplies a signal (TDS), detects a touch sensing signal (TSS) from common electrodes (CEs) to which the touch driving signal (TDS) is supplied, and transmits it to the touch controller 192. .

FIG. 3 is a diagram illustrating an example of a touch panel built into a display panel in a touch display device according to embodiments of the present invention.

Referring to FIG. 3, in the touch display device 100 according to embodiments of the present invention, a plurality of common electrodes (CE) may be disposed built into the display panel 110. In other words, the display panel 110 of the touch display device 100 can be said to have a built-in touch screen panel (TSP).

That is, the touch panel (TSP) may be implemented to be embedded in the pixel array area of the display panel 110 using an in-cell touch method, and the in-cell touch touch screen panel (TSP) may be implemented with electrodes formed inside the display panel 110. An electrode configured in the form of a block (or point) can be used as a touch electrode (TE).

Accordingly, in the touch display device 100 according to embodiments of the present invention, the touch panel (TSP) may be viewed as an independent panel with a touch sensing function, or a display panel (TSP) having both a touch sensing function and a display function. 110). Hereinafter, the description will be made assuming the case of the display panel 110 including a touch panel (TSP).

The plurality of common electrodes (CE) built into the display panel 110 not only operate as touch electrodes (touch sensors) as described above, but also serve as a display to which a common voltage (Vcom) opposite to the pixel voltage is applied to display images. It can also work as an electrode.

Meanwhile, a touch driving signal (TDS) is supplied to a plurality of common electrodes (CE) that can operate as a touch electrode during the touch sensing period, and a touch driving signal (TDS) is supplied to a plurality of common electrodes (CE) that can operate as a display electrode during the display driving period. In order to supply the common voltage (Vcom), one touch channel 300 may be connected to each common electrode (CE). That is, one common electrode (CE) can be connected to the touch circuit 190 and the common voltage supply circuit through one touch channel 300.

For example, an organic light emitting display device in which a first electrode, an organic light emitting layer, a second electrode constituting an organic light emitting diode, a sealing layer located on top of the organic light emitting diode and having a sealing function, and a touch electrode (TE) are formed on the top of the organic light emitting diode. In this case, a touch may be sensed by applying a common voltage (Vcom) or a touch driving signal (TDS) to the touch electrode (TE). At this time, the common voltage (Vcom) may be a direct current voltage applied to the touch electrode (TE) during the display driving period, or may be applied to the touch electrode (TE) with the same phase and amplitude as the touch driving signal (TDS) during the touch sensing period. It may be an alternating current signal supplied.

The common electrode (CE) includes a transparent electrode formed of a transparent conductive material such as ITO (Indium Tin Oxide). Each of the transparent electrodes overlaps a plurality of subpixels and is formed as a transparent electrode pattern larger than the size of the subpixels to supply a common voltage (Vcom) to the plurality of subpixels.

“Common” in the common electrode (CE) described in this specification means that the common electrode (CE) is shared as a touch electrode and a display electrode. In other words, “common” means that it is common to touch mode and display mode. In addition to this meaning, “common” may also mean that a “common voltage (Vcom)” is applied to a plurality of common electrodes (CE) operating as display electrodes.

As described above, the touch display device 100 can provide both an image display function and a touch sensing function. For example, it may be a display device such as a TV or monitor, a computer such as a laptop, or a smart phone. , it may be a mobile device such as a tablet.

The touch display device 100 according to embodiments of the present invention may operate in a display mode to provide an image display function and a touch mode to provide a touch sensing function.

Figure 4 is a diagram showing a conventional touch sensing circuit in a touch display device.

Referring to FIG. 4 , in the touch display device 100, n touch channels 300 are each connected to n common electrodes (CE) formed on the display panel 110. Here, the common electrode (CE) supplies a touch sensing signal (TSS) to the touch sensing circuit 194 through the touch channel 300 by a touch input applied to the display panel 110, so it is a touch electrode or touch sensor. plays the role of

The touch sensing circuit 194 including a plurality of sensing units (SSU) receives a touch sensing signal (TSS) through n touch channels 300. That is, n sensing units (SSU) are each connected to n touch channels 300 and receive a self-capacitance or mutual capacitance signal as a touch sensing signal (TSS).

At this time, each sensing unit (SSU) may be connected to a second touch channel adjacent to the first touch channel to which it is connected. In this case, each sensing unit (SSU) may differentially receive a first touch sensing signal input from the first touch channel and a second touch sensing signal input from the second touch channel. The touch sensing circuit 194 detects a change in the capacitance value of the common electrode (CE) and generates touch sensing output data (Sout) of a predetermined bit.

The sensing unit (SSU) connected to the specific touch channel 300 consists of an operational amplifier (OP Amp), and is connected between the inverting input terminal (-) and the display panel 110 to transmit a touch sensing signal (TSS). It includes a first multiplexer (MUX_0) and a second multiplexer (MUX_1) connected between a non-inverting input terminal (+) and the display panel 110 to transmit a common voltage (Vcom), and a non-inverting input terminal (+) A common voltage (Vcom) is applied to . The first multiplexer (MUX_0) and the second multiplexer (MUX_1) correspond to switches that transmit a touch sensing signal (TSS) and a common voltage (Vcom) according to a control signal, respectively, and can operate as a switch in addition to a multiplexer. It may be replaced with another circuit element.

This touch sensing circuit 194 is an inverter (INV) between the first multiplexer (MUX_0) connected to the inverting input terminal (-) of the sensing unit (SSU) and the second multiplexer (MUX_1) connected to the non-inverting input terminal (+). ), so that when the first multiplexer (MUX_0) is turned on by the switching signal (SW0), the second multiplexer (MUX_1) is automatically turned off.

Therefore, the first multiplexer (MUX_0) is turned on by the switching signal (SW0), the touch sensing signal (TSS) flows into the inverting input terminal (-) of the sensing unit (SSU), and the ratio of the sensing unit (SSU) When the common voltage (Vcom) is applied to the inverting input terminal (+), the sensing unit (SSU) compares the touch sensing signal (TSS) and the common voltage (Vcom) to generate touch sensing output data (Sout).

Conversely, when the first multiplexer (MUX_0) is turned off by the switching signal (SW0) and the second multiplexer (MUX_1) connected to the non-inverting input terminal (+) is turned on, the common voltage (Vcom) is displayed. This will be applied to panel 110.

At this time, the first multiplexer (MUX_0) and the second multiplexer (MUX_1) connected to the sensing unit (SSU) may be configured as one block, and depending on the pixel configuration of the display panel 110, the display panel is displayed in block units. It can be connected to (110).

For example, when the gate line (GL) of the display panel 110 is divided into 10 blocks consisting of a certain number of columns, and the first multiplexer (MUX_0) and the second multiplexer (MUX_1) are connected to each block. , 10 groups of multiplexers (MUX0 to MUX9), in which the first multiplexer (MUX_0) and the second multiplexer (MUX_1) form one group, may be connected to the touch sensing circuit 194.

Above, the first multiplexer (MUX_0) and the second multiplexer (MUX_1) were described for the purpose of sensing the touch signal of the display panel 110 or applying the common voltage (Vcom) to the display panel 110, but the display panel ( Since it is used for the purpose of controlling the signal direction between 110) and the sensing unit (SSU), it may be expressed as a switch.

Figure 5 is a diagram showing an operation mode of a touch display device according to embodiments of the present invention.

Referring to FIG. 5, the touch display device 100 according to embodiments of the present invention has two operation modes, including a display mode for providing an image display function and a touch mode for providing a touch sensing function. . These operation modes may be divided in time or may overlap in the same time period.

For example, in Case A, the touch display device 100 may operate in a display mode or a touch mode at a certain point in time. In this case, the display mode and touch mode can be time-divided, and the display mode section and the touch mode section are separated in time.

The display mode and touch mode can be temporally divided by a time division control signal. For example, when the time division control signal is at a low level (“0”), it operates in touch mode, and when the time division control signal is at a high level (“0”), it operates in touch mode. 1”), it can operate in display mode. Additionally, the number of operations in the display mode and touch mode can be controlled by allowing the time division control signal to change the voltage level only once or more than twice during one frame period.

When the display mode and the touch mode are separated in time, the second multiplexer (MUX_1) is turned on during the display driving period in which the display is performed, and the common voltage (Vcom) is applied to the display panel 110, and the touch sensing is performed. In the sensing section, the first multiplexer (MUX_0) is turned on and the touch sensing signal (TSS) is applied from the display panel 110 to the sensing unit (SSU).

On the other hand, in Case B and Case C, the touch display device 100 may operate in both the display mode and the touch mode at the same time. In this case, the display mode and the touch mode may proceed spatially independently, and the display mode section and the touch mode section may overlap temporally.

Below, a case in which the touch display device 100 is operated by temporally dividing the display mode and the touch mode will be described as an example, but the operation of the display mode and touch mode may be changed in various ways.

In the case of this touch display device 100, when a noise signal such as a high-output radio signal (RF) or electro-static discharge (ESD) flows into the display panel 110 during the display driving period, this causes This affects the display panel 110, causing errors in not only touch sensing but also display operation.

FIG. 6 is a diagram illustrating an example of a display error occurring in a display panel when a noise signal such as a walkie-talkie signal is introduced into the touch display device.

Referring to FIG. 6, the multiplexer (MUX) used in the touch sensing circuit 194 may be configured in groups, in which case the display panel 110 may be blurred in blocks due to noise such as radio signals. A phenomenon (Dim) occurs.

Figure 7 is a diagram showing a signal timing diagram in which noise such as a radio signal flows into a touch display device, and Figures 8 and 9 are diagrams showing a circuit operation when a display error occurs due to noise such as a radio signal.

Referring to FIGS. 7 to 9, the touch display device 100 may have 10 group multiplexers (MUX0 to MUX9) connected to the touch sensing circuit 194 for touch sensing of the display panel 110, and each group multiplexer (MUX0 to MUX9) may be composed of a first multiplexer (MUX_0) and a second multiplexer (MUX_1).

In the case of the touch display device 100 in which the display mode and the touch mode are temporally divided, a first multiplexer (MUX0 to MUX9) is connected to the touch sensing circuit 194 before entering the display mode or touch mode. All MUX_0) maintain a turn-off state, and the common voltage (Vcom) is applied to the display panel 110 through the second multiplexer (MUX_1).

In this state, when high-output noise such as a walkie-talkie signal flows into the touch display device 100, charges are accumulated in the common voltage (Vcom) line and the potential of the common voltage (Vcom) increases.

When entering the touch mode with charges accumulated due to high-output noise on the line to which the common voltage (Vcom) is applied, the first multiplexer (MUX0_0) of the first group multiplexer (MUX0) is turned on. At this time, The charge accumulated in the common voltage (Vcom) line flows into the first group multiplexer (MUX0), causing a malfunction.

In this state, when the touch mode ends and the display mode is entered, the second multiplexer (MUX0_1) of the first group multiplexer (MUX0) must be turned on and the common voltage (Vcom) must be applied to the display panel 110. Because the common voltage (Vcom) is floating due to a malfunction of the first group multiplexer (MUX0), blurring occurs in the block of the display panel 110 to which the first group multiplexer (MUX0) is connected. .

On the other hand, since the interval between when the second group multiplexer (MUX1) is turned on and when the first group multiplexer (MUX0) is turned on is relatively short, there is a low possibility that noise such as a radio signal will be introduced. , Since the incoming noise is not large, it can be said that there is a low possibility of malfunction of the second group multiplexer (MUX1) or blurring of the touch panel (TSP).

In order to solve this problem, the touch display device 100 of the present invention determines whether noise is introduced, and when noise is introduced, the touch circuit 190 can discharge the charge accumulated in the common voltage (Vcom) line. ).

Figure 10 is a block diagram showing the configuration of a touch circuit in a touch display device according to embodiments of the present invention.

Here, only one random group multiplexer (MUX) among a plurality of group multiplexers (MUX) is shown as an example.

Referring to FIG. 10, the touch display device 100 according to embodiments of the present invention is connected to the display panel 110 through the touch channel 300 and is capable of determining the inflow of noise and discharging the incoming noise. Includes touch circuitry 194.

The touch circuit 194 receives the touch sensing signal (TSS) from the display panel 110 through the first multiplexer (MUX_0) and applies a common voltage (Vcom) to the display panel 110 through the second multiplexer (MUX_1). A noise detection circuit 196 for determining whether noise is introduced between the supplied sensing unit (SSU), the display panel 110, and the sensing unit (SSU), and a noise detection signal output from the noise detection circuit 196 ( Cout), a switching circuit 198 that controls the operation of the first multiplexer (MUX_0) and the second multiplexer (MUX_1), and a discharge circuit for discharging noise introduced into the common voltage line through which the common voltage (Vcom) is transmitted. Includes (200).

The touch sensing signal (TSS) transmitted from the display panel 110 through the first multiplexer (MUX_0) is input to the inverting input terminal (-) of the sensing unit (SSU).

The non-inverting input terminal (+) of the sensing unit (SSU) is connected to the common voltage (Vcom) line, and the common voltage (Vcom) is supplied to the display panel 110 through the second multiplexer (MUX_1).

At this time, noise such as a radio signal may be introduced during the display mode or touch mode operation, and the introduced noise is transmitted through the touch sensing signal (TSS) between the display panel 110 and the sensing unit (SSU). It can accumulate on the line or common voltage line through which the common voltage (Vcom) is transmitted.

Accordingly, the noise detection circuit 196 may be connected to a touch sensing line or a common voltage line where noise may accumulate to determine whether noise exists. Here, the case where the noise detection circuit 196 is connected to the inverting input terminal (-) of the sensing unit (SSU) is shown, but the noise detection circuit 196 is connected to the non-inverting input terminal (+) of the sensing unit (SSU) or close to the display panel 110. It may also be connected to the touch channel 300.

The switching circuit 198 uses the noise detection signal (Cout) output from the noise detection circuit 196 and the multiplexer control signal (CTRL_MUX) transmitted from the touch controller 192 to invert the inverting input terminal ( Controls the operation of the first multiplexer (MUX_0) connected to -) and the second multiplexer (MUX_1) connected to the inverting input terminal (+).

For example, when the noise detection circuit 196 determines that no noise has entered the touch sensing line or the common voltage line and outputs the noise detection signal Cout at a low level, the switching circuit 198 operates the touch controller ( 192), the operations of the first multiplexer (MUX_0) and the second multiplexer (MUX_1) will be normally controlled according to the multiplexer control signal (CTRL_MUX) transmitted.

At this time, the multiplexer control signal (CTRL_MUX) transmitted from the touch controller 192 is a first multiplexer control signal that controls the operation of the first multiplexer (MUX_0) and a second multiplexer control signal that controls the operation of the second multiplexer (MUX_1) It may be composed of signals, and the first multiplexer control signal and the second multiplexer control signal may be signals whose phases are opposite to each other.

On the other hand, when the noise detection circuit 196 determines that noise has entered the touch sensing line or the common voltage line and outputs the noise detection signal Cout at a high level, the switching circuit 198 operates in the touch controller 192. Regardless of the transmitted multiplexer control signal (CTRL_MUX), the first multiplexer (MUX_0) and the second multiplexer (MUX_1) can be turned off.

Additionally, the discharge circuit 200 is connected to the non-inverting input terminal (+) of the sensing unit (SSU) and discharges noise flowing into the common voltage line to the ground terminal.

Here, the case where the discharge circuit 200 is connected to the non-inverting input terminal (+) of the sensing unit (SSU) to which the common voltage (Vcom) is applied is shown, but the touch channel 300 located close to the display panel 110 Alternatively, it may be connected to the inverting input terminal (-) of the sensing unit (SSU) through which the touch sensing signal (TSS) is transmitted.

Accordingly, the touch display device 100 of the present invention has a sensing unit (SSU) when noise flows into the touch sensing line through which the touch sensing signal (TSS) is transmitted or the common voltage line through which the common voltage (Vcom) is transmitted. By blocking the multiplexers (MUX_0, MUX_1) connected to and discharging noise introduced through the discharge circuit 200, blurring of the display panel 110 can be prevented and stable display and touch sensing can be achieved.

Figure 11 is a diagram showing a noise detection circuit for determining noise inflow in a touch display device according to embodiments of the present invention.

Referring to FIG. 11, the noise detection circuit 196 for determining noise inflow in the touch display device 100 according to embodiments of the present invention includes a resistor string (R1) connected in series between the reference voltage (Vref) and ground. , …, R5), and the normal voltages (Vn1, Vn2) distributed by the resistor strings (R1, …, R5) by receiving the touch sensing signal (TSS) or common voltage (Vcom) as the noise input signal (Cin) It consists of a first comparator (C1) and a second comparator (C2) for comparison, and an OR gate (OR) for outputting a noise detection signal (Cout) according to the outputs of the first comparator (C1) and the second comparator (C2). You can.

The resistor string (R1, ..., R5) consists of a resistor connected in series between the reference voltage (Vref) and ground to determine the normal range of the touch sensing signal (TSS) or the common voltage (Vcom), and is connected to the first comparator Range between the voltage (Vn1) of the first point connected to the inverting input terminal (-) of (C1) and the voltage (Vn2) of the second point connected to the non-inverting input terminal (+) of the second comparator (C2) can be set to normal voltage.

Since the noise flowing in through the touch sensing line or common voltage line may be positive or negative, the first normal voltage (Vn1) is set considering the case where positive noise is introduced, and the first normal voltage (Vn1) is set considering the case where negative charge noise is introduced. The range between the second normal voltages (Vn2) can be set to the normal range.

Therefore, when the noise input signal Cin is smaller than the first normal voltage Vn1, the first comparator C1 determines it to be normal and outputs a low level signal, and the noise input signal Cin is less than the first normal voltage Vn1. If it is greater than (Vn1), it is determined that noise has entered and a high level signal is output.

Additionally, when the noise input signal Cin is greater than the second normal voltage Vn2, the second comparator C2 determines it to be normal and outputs a low level signal, and the noise input signal Cin is greater than the second normal voltage Vn2. If it is less than (Vn2), it is judged that noise has entered and a high level signal is output.

As a result, the OR gate (OR) generates a high-level noise detection signal (Cout) when a high-level signal is output from the first comparator (C1) or a high-level signal is output from the second comparator (C2). output, and the noise detection signal Cout is supplied to the switching circuit 198.

Figure 12 is a diagram showing a switching circuit for controlling a signal supplied to a sensing unit in a touch display device according to embodiments of the present invention.

Referring to FIG. 12, the switching circuit 198 for controlling the signal supplied through the sensing unit (SSU) in the touch display device 100 according to embodiments of the present invention transmits the touch sensing signal (TSS) to the sensing unit. Controls the operation of the first XOR gate ( It consists of a second XOR gate (XOR2) to do this.

The first A first switching signal (SW0) for controlling is output.

The second A second switching signal (SW1) for controlling is output.

The first multiplexer control signal (CTRL_MUX_0) and the second multiplexer control signal (CTRL_MUX_1) may be signals whose phases are opposite to each other.

Therefore, when the low-level noise detection signal Cout is applied from the noise detection circuit 196 to the first XOR gate (XOR1) and the second XOR gate (XOR2), the first multiplexer The inverted signal of the control signal (CTRL_MUX_0) is output as the first switching signal (SW0), and the inverted signal of the second multiplexer control signal (CTRL_MUX_1) is output as the second switching signal (SW1) from the second XOR gate (XOR2). .

Therefore, in this case, the first switching signal (SW0) and the second switching signal (SW1), which control the operations of the first multiplexer (MUX_0) and the second multiplexer (MUX_1) in the switching circuit 198, have opposite phases to each other. With this, the first multiplexer control signal (CTRL_MUX_0) and the second multiplexer control signal (CTRL_MUX_1) are toggled according to the timing.

That is, when the touch sensing signal (TSS) or the common voltage (Vcom) is within the normal range, the low-level noise detection signal (Cout) is transmitted from the noise detection circuit 196 to the switching circuit 198, and the switching circuit ( In 198), the first multiplexer (MUX_0) and the second multiplexer (MUX_1) are turned on according to the cycle in which the first multiplexer control signal (CTRL_MUX_0) and the second multiplexer control signal (CTRL_MUX_1) transmitted from the touch controller 192 are toggled. By turning it off, normal touch sensing operation and display operation are achieved.

On the other hand, when a high-level noise detection signal (Cout) indicating noise inflow from the noise detection circuit 196 is applied to the first XOR gate (XOR1) and the second XOR gate (XOR2), the first multiplexer control signal ( Regardless of the levels of the CTRL_MUX_0) and the second multiplexer control signals (CTRL_MUX_1), the first XOR gate (XOR1) and the second XOR gate (XOR2) output low level switching signals (SW0, SW1).

As a result, when it is determined that noise has been introduced, the first multiplexer (MUX_0) and the second multiplexer (MUX_1) are turned off by the low-level switching signals (SW0, SW1) output from the switching circuit 198. , blocks noise from entering the display panel 110 and prevents blurring.

Figure 13 is a diagram showing a discharge circuit that discharges noise flowing into the display panel in a touch display device according to embodiments of the present invention.

Referring to FIG. 13, in the touch display device 100 according to embodiments of the present invention, the discharge circuit 200 for discharging noise introduced into the display panel 110 includes a first discharge circuit for discharging negative charge noise ( 210) and a second discharge circuit 220 for discharging positive noise.

The first discharge circuit 210 for discharging negative charge noise includes a first discharge transistor (T1) whose drain terminal and source terminal are connected between the common voltage line and ground, and a first discharge transistor (T1) between the high level voltage (VH) and ground. It may be comprised of a plurality of inverters (INV11, INV12, INV13) connected in series between the node (N1) and the gate terminal of the first discharge transistor (T1).

Here, the discharge circuit 200 is connected to a common voltage line to which the common voltage (Vcom) is supplied, but it may also be connected to a touch sensing line to which the touch sensing signal (TSS) is transmitted.

The high level voltage (VH) may correspond to a higher level voltage value among the levels within the normal range, and when negative charge noise is introduced, the high level voltage (VH) will instantly change to a low level voltage.

A resistor (R11) and a capacitance (C11) may be connected between the high level voltage (VH) and ground to effectively transmit changes in the high level voltage (VH) due to negative charge noise.

At this time, since an odd number of inverters (INV11, INV12, INV13) are connected in series between the first node (N1) between the high level voltage (VH) and ground and the gate terminal of the first discharge transistor (T1), normal In this state, a low level voltage is applied to the gate terminal of the first discharge transistor T1, and the first discharge transistor T1 remains in the off state.

If negative charge noise flows into the touch sensing line or the common voltage line, the high level voltage (VH) of the first discharge circuit 210 momentarily changes to a low level, which causes the first discharge transistor (T1) to change to a low level. A high level voltage is applied to the gate terminal to turn on the first discharge transistor (T1). As a result, noise accumulated in the common voltage line is discharged to ground through the first discharge transistor (T1).

The second discharge circuit 220 for discharging positive noise includes a second discharge transistor (T2) whose drain terminal and source terminal are connected between the common voltage line and ground, and a second discharge transistor (T2) between the low level voltage (VL) and ground. It may be comprised of a plurality of inverters (INV21, INV22, INV23, INV24) connected in series between the node (N2) and the gate terminal of the second discharge transistor (T2).

The low level voltage (VL) may correspond to a lower level voltage value among the levels within the normal range, and when positive charge noise is introduced, the low level voltage (VL) will instantly change to a low level voltage.

A resistor (R21) and a capacitance (C21) may be connected between the low level voltage (VL) and the ground to effectively transmit changes in the low level voltage (VL) due to positive noise.

At this time, an even number of inverters (INV21, INV22, INV23, INV24) are connected in series between the second node (N2) between the low level voltage (VL) and ground and the gate terminal of the second discharge transistor (T2). , In the normal state, a low level voltage is applied to the gate terminal of the second discharge transistor T2, so that the second discharge transistor T2 remains in the off state.

If positive charge noise flows into the touch sensing line or the common voltage line, the low level voltage (VL) of the second discharge circuit 220 momentarily changes to a high level, which causes the second discharge transistor (T2) to change to a high level. A high level voltage is applied to the gate terminal to turn on the second discharge transistor (T2). As a result, noise accumulated in the common voltage line is discharged to ground through the second discharge transistor (T2).

Figure 14 is a diagram showing a touch circuit for discharging noise introduced into the display panel in a touch display device according to embodiments of the present invention.

Referring to FIG. 14, in the touch display device 100 according to embodiments of the present invention, the touch circuit 194 for discharging noise flowing into the display panel 110 is a touch circuit through which a touch sensing signal (TSS) is transmitted. When noise enters the sensing line or the common voltage line through which the common voltage (Vcom) is transmitted, low-level switching signals (SW0, SW1) are output through the switching circuit 198 to be connected to the first multiplexer (MUX_0) and the second multiplexer (MUX_0). 2 Switch the multiplexer (MUX_1) to the off state and discharge the noise accumulated in the touch sensing line or common voltage line through the discharge circuit 200, thereby blocking noise from flowing into the display panel 110 and preventing blurring. This can be prevented from appearing.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention. In addition, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but rather to explain it, and therefore the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

100: touch display device 110: display panel
120: data driving circuit 130: gate driving circuit
121, 131: film 140: timing controller
150: power management integrated circuit 160: source printed circuit board
170: control printed circuit board 180: connection member
190: touch circuit 192: touch controller
194: touch sensing circuit 196: noise detection circuit
198: switching circuit 200: discharge circuit
210: first discharge circuit 220: second discharge circuit
300: Touch channel

Claims (18)

sensing unit;
a first switch connected between a touch panel and a first input terminal of the sensing unit to transmit a touch sensing signal;
a second switch transmitting a common voltage connected between the touch panel and a second input terminal of the sensing unit;
a noise detection circuit connected to the first input terminal or the second input terminal of the sensing unit to detect noise inflow;
a switching circuit that controls operations of the first switch and the second switch according to a noise detection signal output from the noise detection circuit; and
A discharge circuit connected to the first input terminal or the second input terminal of the sensing unit and discharging noise according to a change in the level of the internal voltage,
The noise detection circuit is
A resistor string connected in series between a reference voltage and ground;
a first comparator that compares the touch sensing signal or the common voltage with a first normal voltage distributed by the resistor string;
a second comparator that compares the touch sensing signal or the common voltage with a second normal voltage distributed by the resistor string; and
A touch circuit including an OR gate that outputs a noise detection signal according to the outputs of the first comparator and the second comparator.
According to claim 1,
The first switch and the second switch are
Touch circuit as multiplexer.
delete According to claim 1,
The touch sensing signal or the common voltage
A touch circuit that determines that noise has not entered the touch sensing signal or the common voltage when it falls within a range between the first normal voltage and the second normal voltage.
According to claim 1,
The switching circuit is
a first XOR gate that receives the noise detection signal of the noise detection circuit and the control signal of the first switch as input and outputs a first switching signal to the first switch; and
A touch circuit including a second XOR gate that receives the noise detection signal of the noise detection circuit and the control signal of the second switch as input and outputs a second switching signal to the second switch.
According to claim 1,
The switching circuit is
A touch circuit that turns off the first switch and the second switch when the noise detection signal of the noise detection circuit is at a high level.
According to claim 1,
The discharge circuit is
a first discharge circuit for discharging negative charge noise; and
A touch circuit including a second discharge circuit for discharging positive noise.
According to claim 7,
The first discharge circuit is
a first discharge transistor having a drain terminal and a source terminal connected between the first input terminal or the second input terminal of the sensing unit and ground; and
A touch circuit comprising an odd number of inverters connected in series between a first node between a high level voltage and the ground and a gate terminal of the first discharge transistor.
According to claim 7,
The second discharge circuit is
a second discharge transistor having a drain terminal and a source terminal connected between the first input terminal or the second input terminal of the sensing unit and ground; and
A touch circuit comprising an even number of inverters connected in series between a second node between a low level voltage and the ground and a gate terminal of the second discharge transistor.
A touch panel having a plurality of data lines and a plurality of gate lines and a plurality of subpixels; and
It includes a touch circuit that applies a common voltage to a plurality of touch electrodes constituting the touch panel or senses a touch through a touch sensing signal transmitted from the plurality of touch electrodes,
The touch circuit is
sensing unit;
a first switch connected between the touch panel and a first input terminal of the sensing unit to transmit a touch sensing signal;
a second switch transmitting a common voltage connected between the touch panel and a second input terminal of the sensing unit;
a noise detection circuit connected to the first input terminal or the second input terminal of the sensing unit to detect noise inflow;
a switching circuit that controls operations of the first switch and the second switch according to a noise detection signal output from the noise detection circuit; and
A discharge circuit connected to the first input terminal or the second input terminal of the sensing unit and discharging noise according to a change in the level of the internal voltage,
The switching circuit is
A touch display device that turns off the first switch and the second switch when the noise detection signal of the noise detection circuit is at a high level.
According to claim 10,
The first switch and the second switch are
A touch display device that is a multiplexer.
According to claim 10,
The noise detection circuit is
A resistor string connected in series between a reference voltage and ground;
a first comparator that compares the touch sensing signal or the common voltage with a first normal voltage distributed by the resistor string;
a second comparator that compares the touch sensing signal or the common voltage with a second normal voltage distributed by the resistor string; and
A touch display device including an OR gate that outputs a noise detection signal according to the outputs of the first comparator and the second comparator.
According to claim 12,
The touch sensing signal or the common voltage
A touch display device that determines that no noise has been introduced into the touch sensing signal or the common voltage when it falls within a range between the first normal voltage and the second normal voltage.
According to claim 10,
The switching circuit is
a first XOR gate that receives the noise detection signal of the noise detection circuit and the control signal of the first switch as input and outputs a first switching signal to the first switch; and
A touch display device comprising a second XOR gate that receives the noise detection signal of the noise detection circuit and the control signal of the second switch as input and outputs a second switching signal to the second switch.
delete According to claim 10,
The discharge circuit is
a first discharge circuit for discharging negative charge noise; and
A touch display device comprising a second discharge circuit for discharging positive noise.
According to claim 16,
The first discharge circuit is
a first discharge transistor having a drain terminal and a source terminal connected between the first input terminal or the second input terminal of the sensing unit and ground; and
A touch display device comprising an odd number of inverters connected in series between a first node between a high level voltage and the ground and a gate terminal of the first discharge transistor.
According to claim 16,
The second discharge circuit is
a second discharge transistor having a drain terminal and a source terminal connected between the first input terminal or the second input terminal of the sensing unit and ground; and
A touch display device comprising an even number of inverters connected in series between a second node between a low level voltage and the ground and a gate terminal of the second discharge transistor.

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