KR20170080912A - Touch force sensing method, display device, and processor - Google Patents

Abstract

The present invention relates to a force sensing technique, and more particularly, to a force sensing technique for applying a first electrode driving signal to a first electrode built in a display panel during each touch driving period, A touch force sensing method for recognizing a touch force based on a corrected signal intensity by correcting a signal intensity of a received signal received through a first electrode after applying a second electrode driving signal to the second electrode, .

Description

TECHNICAL FIELD [0001] The present invention relates to a touch force sensing method, a display device, and a processor (TOUCH FORCE SENSING METHOD, DISPLAY DEVICE, AND PROCESSOR)

The embodiments relate to touch force sensing techniques.

2. Description of the Related Art [0002] As an information society develops, there is a growing demand for display devices for displaying images. Various types of display devices such as a liquid crystal display device, a plasma display device, and an organic light emitting liquid crystal in- .

Among display devices, mobile devices such as smart phones and tablets, and medium and large-sized devices such as smart TVs, etc., provide touch-based input processing according to user convenience and device characteristics.

Such a display device capable of touch input processing is being developed to provide more various functions, and user demands are also becoming more diverse.

However, currently applied touch input processing is a method of sensing only the touch position (touch coordinates) of the user and performing related input processing at the sensed touch position, and it provides a variety of various functions in various forms, There is a limit to the current situation that needs to be met.

The embodiments of the present invention provide a display device having a force sensor structure capable of sensing a touch force that a user presses a screen when a user touches the touch screen in order to provide various functions in various forms I have to.

 It is another object of the present embodiments to provide a display device having a force sensor structure capable of sensing a touch force more precisely and finely.

In one aspect, the present embodiments provide a plasma display apparatus comprising: a plurality of first electrodes embedded in a display panel; at least one second electrode located outside the display panel; and a plurality of second electrodes, And a touch circuit which sequentially applies an electrode driving signal and applies a second electrode driving signal to the second electrode and senses a touch force of a touch based on a reception signal received through the first electrode, A display device having a structure can be provided.

The touch circuit of the display device may correct the signal intensity of the received signal based on the position of the first electrode and recognize the touch force based on the corrected signal intensity.

According to another aspect of the present invention, the first electrode driving signal is applied to the first electrode included in the display panel during each touch driving period, and the second electrode driving signal is applied to at least one second electrode located outside the display panel Applying a signal to the first electrode; receiving a received signal through the first electrode; correcting the signal strength of the received signal; and recognizing the touch force based on the corrected signal strength. Can be provided.

According to another aspect of the present invention, the first electrode driving signal is applied to the first electrode included in the display panel during each touch driving period, and the at least one second electrode located outside the display panel is applied with the second electrode And a control unit for recognizing a touch force based on the corrected signal intensity, wherein the signal strength of the received signal is determined based on the signal intensity of the received signal, A processor for touch force recognition can be provided.

According to the embodiments described above, in order to provide various functions in various forms, not only sensing touch coordinates when a user generates a touch, but also sensing a touch force that the user presses the screen when touching can do.

Further, according to the embodiments, the touch force can be sensed more precisely and finely.

1 is a schematic configuration diagram of a touch system of a display device having a force sensor structure according to the present embodiments.
2 is a view showing a driving period of a display device having a force sensor structure according to the present embodiments.
3 is a diagram illustrating a structure of a touch system according to the present embodiments.
4 is a diagram for explaining a touch driving method according to the present embodiments.
5 is an exemplary diagram illustrating a first electrode driving signal for driving the first electrode and a second electrode driving signal for driving the second electrode in the touch system according to the present embodiments.
6 is a view illustrating another example of the first electrode driving signal for driving the first electrode and the second electrode driving signal for driving the second electrode in the touch system according to the present embodiments.
7 is an exemplary diagram of a touch circuit according to the present embodiments.
FIG. 8 is a diagram illustrating a received signal strength according to the soft touch and a received signal strength according to the force touch in the touch system according to the present embodiments.
9A and 9B are diagrams showing a signal intensity distribution according to a soft touch and a force touch in a touch system according to the present embodiments.
10 is a view schematically showing a touch system according to the present embodiments.
11 is a view showing a display device having a force sensor structure according to the present embodiments.
12 is a cross-sectional view of a display device having a force sensor structure according to the present embodiments.
FIG. 13 is a view illustrating a situation in which a size of a gap is changed due to a force touch occurring in a display device having a force sensor structure according to the present embodiments.
14A and 14B are diagrams showing a circuit for applying a driving signal in a display device having a force sensor structure according to the present embodiments.
FIG. 15 is a graph showing the intensity of a received signal according to the generation position of a force touch in a display device having a force sensor structure according to the present embodiments.
FIG. 16 is a view illustrating a processor for compensating for a reception signal deviation according to a generation position of a force touch in a display device having a force sensor structure according to the present embodiments.
FIG. 17 is a schematic view of a look-up table for compensating a received signal deviation according to a generation position of a force touch in a display device having a force sensor structure according to the present embodiments.
18 is a graph illustrating a signal intensity compensated according to a result obtained by compensating for a reception signal variation according to a generation position of a force touch in a display device having a force sensor structure according to the present embodiments.
19A to 19C are views for explaining a method of finely recognizing the size of a touch force in a display device having a force sensor structure according to the present embodiments.
20 is a flowchart of a touch force sensing method of a display device having a force sensor structure according to the present embodiments.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the components from other components, and the terms do not limit the nature, order, order, or number of the components. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; intervening "or that each component may be" connected, "" coupled, "or " connected" through other components.

1 is a schematic configuration diagram of a touch system 100 of a display device having a force sensor structure according to the present embodiments.

Referring to FIG. 1, a display device having a force sensor structure according to the present embodiments includes a touch system 100 for sensing a touch generated by a pointer such as a finger or a pen.

The touch system 100 according to the present embodiments can sense a touch force corresponding to a force (pressure) applied at the time of touch as well as sensing whether a touch is generated and coordinates of the touch.

The touch referred to herein means an action that a user touches the display panel 110 with a pointer and a touch force refers to a force that the user presses the display panel 110 when touching Pressure). The touch coordinates indicate a position of a point where the user touches the display panel 110. [

In addition, the Force Touch referred to in the present specification refers to a touch having a force (pressure) or a certain level of pressing force on the display panel 110, and a soft touch indicates a touch Means a touch having no pressing force (pressure) or less than a certain level.

Also, for touch coordinate sensing, the pointer must be a pointer containing a conductive material, such as a finger, pen, or the like, or of a conductive material. However, the pointer for touch force sensing may be a pointer made of a conductor material as well as a non-conductive material, and anything that can force it is possible.

Accordingly, the touch system 100 according to the present embodiment includes a plurality of first electrodes E1 necessary for obtaining a touch and generating coordinates of a touch, a second electrode E2 for sensing a touch force of the touch, A touch circuit 120 for driving the plurality of first electrodes E1 and the second electrodes E2 to sense the presence or absence of a touch and the touch coordinates of the touch, .

A plurality of first electrodes E1 corresponding to a touch sensor necessary for obtaining whether or not a touch is generated and coordinates of a touch are arranged on a touch screen panel separate from the display panel 110 Or may be embedded in the display panel 110. FIG.

When the plurality of first electrodes E1 are embedded in the display panel 110, the display panel 110 may include a plurality of first electrodes E1 serving as touch sensors, Display panel ".

The touch screen built in the display panel 110 may be an in-cell or an on-cell type touch screen panel.

The second electrode E2 necessary to sense a touch force corresponding to a force applied at the time of touching is positioned on the outside of the display panel 110 can do.

In the touch system 100 according to the present embodiment, a plurality of first electrodes E1 for sensing presence / absence of touch and touch coordinates are driven and a second electrode E2 May be performed in the same driving process of touch driving.

In other words, the touch circuit 120 of the touch system 100 according to the present embodiment sequentially applies the first electrode driving signal DS1 to the plurality of first electrodes E1 during one touch driving period And the second electrode driving signal DS2 to the second electrode E2. That is, a plurality of first electrodes E1 and a plurality of second electrodes E2 are driven together during one touch driving period.

Accordingly, in the touch system 100 according to the present embodiment, a plurality of first electrodes E1 built in the display panel 110 and a second electrode E2 positioned outside the display panel 110 are combined It can be called "Force Sensor". The plurality of first electrodes E1 embedded in the display panel 110 may be referred to as a "touch sensor" or a "touch electrode ".

As described above, in the touch system 100 according to the present embodiments, the first electrode driving and the second electrode driving can be performed in the same touch driving process (touch driving interval) The second electrode driving is carried out separately through different driving processes (different touch driving sections), and the sensing of the presence or absence of touch and the sensing of the touch coordinates and the touch force sensing can be performed in a shorter time.

In the touch system 100 according to the present embodiment, the touch circuit 120 generates the second electrode driving signal DS2 based on the first electrode driving signal DS1, The driving signal DS2 can be generated.

Accordingly, the second electrode driving signal DS2 is a signal corresponding to the first electrode driving signal DS1.

For example, the second electrode driving signal DS2 is in phase with the first electrode driving signal DS1. The signal characteristics of the first electrode driving signal DS1 and the second electrode driving signal DS1 will be described later.

The touch circuit 120 may include various types of circuits for generating the second electrode driving signal DS2, and may include a level shifter, for example, and in some cases, And may include a phase shifter.

When the level shifter or the phase shifter is used to generate the first electrode driving signal DS1 in the touch circuit 120 or another device without newly generating the second electrode driving signal DS2, The second electrode driving signal DS2 can be easily and efficiently generated through a process such as shifting the level of the first electrode driving signal DS1 or inverting the phase.

The touch driving section in which the first electrode driving and the second electrode driving are performed together may be performed together with the display driving section for image display or may be time-divided with the display driving section and proceeded between the display driving sections.

Hereinafter, a case in which the display driving and the touch driving respectively proceed in the time-divisional display driving section and the touch driving section will be described with reference to FIG.

2 is a view showing a driving period of a display device having a force sensor structure according to the present embodiments.

Referring to FIG. 2, the display device having the force sensor structure according to the present exemplary embodiments can time-divide one frame period into a display driving period and a touch driving period.

During the touch driving period, the first electrode driving and the second electrode driving can be simultaneously performed.

Accordingly, during the touch driving period, the first electrode driving signal DS1 is sequentially applied to the plurality of first electrodes E1, and the second electrode driving signal DS2 is applied to the second electrode E2 at this time .

Meanwhile, the plurality of first electrodes E1 embedded in the display panel 110 may be a dedicated electrode for touch sensing, or a display driving electrode required for driving the display.

For example, the plurality of first electrodes E1 embedded in the display panel 110 may be a common voltage electrode to which the common voltage Vcom is applied during the display driving period.

That is, the plurality of first electrodes E1 receive the common voltage as the display driving voltage during the display driving, and can sequentially receive the first electrode driving signal DS1 during the touch driving.

As described above, since the first electrode E1 is a mode common electrode that can also be used as a display driving electrode, there is no need to separately form electrodes for two purposes on the display panel 110. [ Therefore, the panel design can be made simple and the panel structure can be simplified.

Hereinafter, the structure and the touch driving method for sensing touch coordinates and touch force by the touch system 100 according to the present embodiments will be described in more detail.

FIG. 3 is a view schematically showing the structure of the touch system 100 according to the present embodiments.

Referring to FIG. 3, in the present embodiment, the touch system 100 utilizes a dedicated pressure sensor for pressure sensing, such as a conventional pressure sensing method, to sense a touch force (pressing force) of a touch A second electrode E2 located outside the display panel 110 for touch force sensing and a plurality of first electrodes E1 embedded in the display panel 110 for touch coordinates calculation are used together There is a peculiar point in that the touch force is sensed by the capacitance method.

That is, the plurality of first electrodes E1 and the second electrodes E2 may be driven together to perform sensing on the touch force. In this regard, the force sensor for sensing the touch force may include a plurality of first electrodes E1 and a plurality of second electrodes E2.

3, the first electrode driving signal DS1 is applied to one of the first electrodes E1 during the touch driving period, and the second electrode driving signal DS2 is applied to the second electrode E2. A first capacitance C1 is formed between a pointer such as a finger and the first electrode E1 and a second capacitance C2 is formed between the first electrode E1 and the second electrode E2 do.

For example, the touch circuit 120 may calculate the touch coordinates and sense the touch force based on the change of the first capacitance C1 and the second capacitance C2.

3, in order to form the second capacitance C2 between the first electrode E1 and the second electrode E2, a gap G between the first electrode E1 and the second electrode E2 ) Must exist.

Here, the gap G can be regarded as a distance between the first electrode E1 and the second electrode E2, and a distance between the structure directly above the second electrode E2 and the second electrode E2 And may be regarded as a distance between the second electrodes E2 on the screen where the touch occurs.

The gap G existing between the first electrode E1 and the second electrode E2 is changed in accordance with the touch force of the touch generated at the upper portion of the display panel 110 for the touch force sensing, The size of the gap G must be changeable.

The change in the size of the gap G may vary from one position to another. The change in the size of the gap for touch force sensing between the center point of the second electrode E2 and the plurality of first electrodes E1, And the size of the gap for the touch force sensing between the first electrode E1 and the edge point of the first electrode E1.

This is caused by a structural feature for touch force sensing and occurs when the rim portion of the second electrode E2 is bonded or coupled with the surrounding structure.

The second capacitance C2 between the first electrode E1 and the second electrode E2 changes when the gap G undergoes a change in size (displacement) according to the touch force, The touch force can be sensed based on the change amount of the touch sensor C2.

According to the above description, the touch force sensing can be performed by the same capacitance method as the sensing method of the touch position sensing (touch coordinate sensing) for the other kinds of sensing. Therefore, two kinds of sensing (touch position sensing, touch force sensing) can be efficiently performed.

The gap G may exist at various positions between the first electrode E1 and the second electrode E2 and may be an air gap or a dielectric gap, for example.

If the type of the gap G existing between the first electrode E1 and the second electrode E2 is different, a structure must be formed so that a gap G corresponding to the gap G exists. This will be described in more detail later.

4 is a diagram for explaining a touch driving method according to the present embodiments.

The structure of the touch system 100 of FIG. 3 may be schematically shown as shown in FIG.

4, the first electrode driving signal DS1 is applied to one of the first electrodes E1 during the touch driving period, and the second electrode driving signal DS2 is applied to the second electrode E2. A first capacitance C1 is formed between a pointer such as a finger and the first electrode E1 and a second capacitance C2 is formed between the first electrode E1 and the second electrode E2 do.

In this touch driving, the amount of charge Q1 charged in the capacitor between the pointer and the first electrode E1 is determined by the voltage V1 of the first capacitance C1 and the first electrode driving signal DS1.

The amount of charge Q2 charged in the capacitor between the first electrode E1 and the second electrode E2 is determined by the second capacitance C2, the voltage V1 of the first electrode driving signal DS1, Can be determined by the voltage V2 of the electrode driving signal DS2.

That is, the amount of charge Q1 to be charged in the capacitor between the pointer and the first electrode E1 and the amount of charge Q2 to be charged in the capacitor between the first electrode E1 and the second electrode E2, , And can be expressed as Equation (1) below.

In the following description, two kinds of signals to be used at the time of touch driving (first electrode driving and second electrode driving), that is, signals of the first electrode driving signal DS1 and the second electrode driving signal DS2 Features are described.

5 is an exemplary diagram illustrating a first electrode driving signal DS1 for driving the first electrode and a second electrode driving signal DS2 for driving the second electrode in the touch system 100 according to the present embodiments, 6 is a diagram illustrating another example of the first electrode driving signal DS1 for driving the first electrode and the second electrode driving signal DS2 for driving the second electrode in the touch system 100 according to the present embodiments .

As shown in FIG. 5, the second electrode driving signal DS2 and the first electrode driving signal DS1 may have the same phase.

In this case, it is assumed that the second electrode driving signal DS2 and the first electrode driving signal DS1 are in a positive phase relationship.

As described above, when the second electrode driving signal DS2 and the first electrode driving signal DS1 having the same phase are used, efficient touch driving (second electrode driving and first electrode driving) and efficient sensing (touch force sensing, Touch coordinate sensing) can be made possible. In addition, it is possible to easily generate the second electrode driving signal DS2 and the first electrode driving signal DS1, which are two signals required for the touch driving.

Referring to FIG. 5, the second electrode driving signal DS2 may have a greater signal intensity than the first electrode driving signal DS1. That is, the voltage V2 of the second electrode driving signal DS2 may be higher than the voltage V1 of the first electrode driving signal DS1.

When the voltage V2 of the second electrode driving signal DS2 is higher than the voltage V1 of the first electrode driving signal DS1 as described above, the amount of charge Q2 charged in the capacitor between the second electrode E2, Is negative (-).

In this regard, the signal received from the first electrode E1 is the sum of the amount of charge Q1 charged in the capacitor between the pointer and the first electrode E1 and the amount of charge Q1 between the first electrode E1 and the second electrode E2 (Q1 + Q2), which is the sum of the amount of charge Q2 charged in the capacitor of Q1 and Q2. In this regard, since the amount of charge Q2 charged in the capacitor between the second electrodes E2 has a negative value, Q1 + Q2 becomes smaller than Q1, and the first electrode E1 receives Is reduced.

Therefore, when the second electrode driving signal DS2 and the first electrode driving signal DS1 are in a positive phase relationship, the voltage V2 of the second electrode driving signal DS2 becomes the first electrode driving signal DS1, The signal intensity of the signal received from the first electrode E1 is represented by a negative sign (-) with respect to the baseline so that a soft touch having no pressing force or less than a predetermined level, And force touch that has a pressing force or exceeds a certain level.

As shown in FIG. 6, the second electrode driving signal DS2 and the first electrode driving signal DS1 may have a 180 degree phase difference.

In this case, it is assumed that the second electrode driving signal DS2 and the first electrode driving signal DS1 are in a reverse phase relationship.

When the second electrode driving signal DS2 and the first electrode driving signal DS1 in the opposite phase relationship are used as described above, the voltage V1 of the first electrode driving signal DS1 and the voltage V1 of the second electrode driving signal The second electrode drive signal DS2 in the opposite phase relationship and the second electrode drive signal DS2 in the opposite phase relationship are generated when the sensing method is implemented to be suitable for this case. It may be efficient to use the one electrode driving signal DS1.

Hereinafter, the internal circuit configuration of the touch circuit 120 for sensing the touch coordinates and the touch force through the above-described touch driving will be described as an example.

7 is an exemplary diagram of the touch circuit 120 according to the present embodiments.

7, the touch circuit 120 controls the ON / OFF control of the two switches SW1 and SW10 to switch between a high level having the voltage V1 and a low voltage VO A first electrode driving signal supply section 710 for supplying the electrode driving signal DS1 and a second electrode driving signal supply section 710 for switching the high level having the voltage V2 and the low voltage having the low voltage V0, A second electrode driving signal supply unit 720 for supplying a second electrode driving signal DS2 in the form of a signal and an operational amplifier OP-AMP, a capacitor C and a resistor R, (ADC) for converting the output value of the integrator 730 into a digital value, and a touch coordinate calculation and touch force recognition A processor 740, and so on.

Here, at least one of the analog-to-digital converter (ADC) and the processor 740 may be external to the touch circuit 140.

The circuit configuration of the touch circuit 120 shown in FIG. 7 is merely an example for convenience of explanation, and may be implemented in various forms.

Referring to FIG. 7, the touch circuit 120 sequentially applies a first electrode driving signal DS1 to a plurality of first electrodes E1 and a second electrode E2 to a second electrode E2, The driving signal DS2 is applied to the plurality of first electrodes E1 and the plurality of first electrodes E1 and the plurality of first electrodes E1 and the plurality of first electrodes E1, The touching force of the touch can be recognized by sensing the charged amount (or voltage) according to the size change of the gap G. [

7, when the pointer is made of an insulator material, the touch circuit 120 can sense only the touch force based on the signal received from each of the plurality of first electrodes E1. However, when the pointer is made of a conductive material The touch circuit 120 can further calculate the coordinate of the touch based on the signal (the input of the integrator 730) received from each of the plurality of first electrodes E1.

7, the signal received from each of the plurality of first electrodes E1 (the input of the integrator 730) includes the amount of charge Q1 charged in the capacitor between the pointer and the first electrode E1, The amount of charge Q2 charged in the capacitor between the electrode E1 and the second electrode E2 corresponds to the summed charge amount Q1 + Q2.

The total charge amount Q1 + Q2 is charged in the capacitor C in the integrator 730 and output from the integrator 730 to the sensing voltage value Vsen.

Accordingly, the analog-to-digital converter (ADC) converts the sensing voltage value Vsen into a digital value.

The processor 740 may calculate the touch coordinates and recognize the touch force based on the digital value output to the analog-to-digital converter (ADC).

According to the above description, the touch coordinate calculation and the force touch recognition can be simultaneously performed based on the signal obtained through the touch driving. Thus, two kinds of sensing (touch sensing, touch force sensing) can be performed quickly and efficiently.

On the other hand, if it is recognized that the touch force is generated, a predetermined application or function corresponding to the touch force can be executed.

The touch circuit 120 senses a charged amount (or voltage) corresponding to a change in the size of the gap G between the first and second electrodes E1 and E2 to detect the charged amount (or voltage) The size of the touch force can be grasped according to the size of the finger.

According to the above description, not only the existence of the touch force corresponding to the force applied at the time of touch but also the size of the touch force indicating how much force is applied can be grasped.

In this regard, if the size of the touch force is grasped, a predetermined application or function corresponding to the size of the detected touch force can be differentiated and executed.

Hereinafter, the characteristic of the received signal generated when the touch system 100 according to the present embodiment is divided into the soft touch and the force touch by performing the touch driving to distinguish the soft touch and the force touch will be described.

FIG. 8 is a diagram illustrating a received signal strength according to a soft touch and a received signal strength according to a force touch in the touch system 100 according to the present embodiments. In FIG. 8, it is assumed that a soft touch is touched with a finger, and a force touch is touched with a non-conductive pointer.

Referring to FIG. 8, the signal intensity of the signal received at the first electrode E1 can be confirmed by a digital value output from the analog-to-digital converter (ADC).

8 and 9, the digital value output from the analog-to-digital converter (ADC) when there is no pressing force or a soft touch of a certain level or less occurs when there is no touch (base line) (+) Direction based on the digital value output from the digital-to-analog converter (ADC).

9, when the soft touch occurs, the magnitude (signal intensity) of the digital value output from the analog-to-digital converter (ADC) is a region corresponding to the position of the first electrode E1 A peak is generated in the light source.

Referring to FIG. 8, when the second electrode driving signal DS2 and the first electrode driving signal DS1 are in a positive phase relationship, when there is a pressing force or a force touch exceeding a certain level The digital value output from the analogue digital converter ADC has a value in the negative direction based on the digital value output from the analogue digital converter ADC when there is no touch (base line).

FIG. 9A is a diagram showing a distribution of signal intensity with respect to a received signal when a soft touch occurs on a screen corresponding to the xy-axis plane. FIG. 9B is a graph showing a distribution of signal strength with respect to a received signal when a force touch occurs on a screen corresponding to the xy- And a signal intensity distribution of the signal.

9A, when a soft touch occurs, the magnitude (signal intensity) of the digital value output from the analog-to-digital converter (ADC) ) In the direction of the signal intensity.

Also, as shown in FIG. 9A, when a soft touch is generated, a signal intensity distribution can be intensively distributed at a point where a soft touch occurs in the entire screen area.

9B, assuming that the second electrode E2 is in the form of a barrel outside the display panel 110, when a force touch occurs, an analog digital converter ADC The magnitude (signal intensity) of the digital value to be output has a distribution in which the signal intensity increases in the negative (-) direction of the z axis as a whole with respect to the baseline.

In addition, as shown in FIG. 9B, when the force touch occurs, the signal intensity at the center of the screen is largest in the negative (-) direction, but the signal intensity gradually increases from the center of the screen to the center.

On the other hand, as the force touch increases, the magnitude of the gap G between the first electrode E1 and the second electrode E2 increases, and thus the digital value output from the analog-to-digital converter ADC (-) direction of the z-axis, based on the digital value output from the analog-to-digital converter (ADC) when there is no touch (baseline) at all. That is, as the strength of the force touch increases, the intensity of the signal increases.

To describe again the directionality described above, a signal received from each of the first electrodes E1 when the touch is a soft touch and a signal received from each of the plurality of first electrodes E1 when the touch is a force touch, The signals received from each of the first electrodes E1 may be signals opposite to each other based on a signal received from each of the plurality of first electrodes E1 when there is no touch.

That is, when the touch is a soft touch, a signal received from each of the plurality of first electrodes E1 has a greater signal intensity than a base line signal obtained when there is no touch, and when the touch is a force touch The signal received from each of the plurality of first electrodes E1 has a smaller signal intensity than the baseline signal.

 When the second electrode driving signal DS2 and the first electrode driving signal DS1 are in a positive phase relationship, the sensed charged amount (Q1 + Q2, Q2? 0) when the touch is a force touch or The corresponding voltage may be less than the sensed charge (Q1 + Q2 = Q1, Q2 = 0) or corresponding voltage when the touch is a soft touch. Here, Q1 and Q2 may be the amount of charged charge or the amount of charged charge.

When the second electrode driving signal DS2 and the first electrode driving signal DS1 are in a positive phase relationship, the charged amount or voltage sensed when the touch is a force touch is sensed when there is no touch Base charge amount or base voltage.

As described above, a signal received from each of the plurality of first electrodes E1 when a touch is a soft touch, based on a signal received from each of the plurality of first electrodes E1 when there is no touch, A signal received from each of the plurality of first electrodes E1 when the touch is a force touch is a signal in a positive (-) direction (or negative (-) direction) Q1 + Q2 detected when the touch is a force touch or a voltage corresponding to the sensed charged amount Q1 (Q1 + Q2) when the touch is a soft touch ) Or a voltage corresponding thereto, the charged amount Q1 + Q2 sensed when the touch is the force touch or the voltage corresponding thereto is the charged amount Q1 sensed when the touch is the soft touch, Or less than the corresponding voltage (Q1 + Q2 < Q1) Soft touch can touch that will accurately distinguish Force (Force Touch) to the pressing force and (Soft Touch) or exceeds a certain level.

Referring to FIG. 8, when the second electrode driving signal DS2 and the first electrode driving signal DS1 are in a reverse phase relationship, when a force is applied or a force touch exceeding a certain level occurs The digital value output from the analog to digital converter ADC has a value in the positive direction based on the digital value output from the analog-to-digital converter ADC when there is no touch (base line) And has a value greater than the digital value output from the analog-to-digital converter (ADC) when a soft touch occurs that has no force or a certain level.

When the second electrode driving signal DS2 and the first electrode driving signal DS1 are in a reverse phase relationship, the sensed charged amount (Q1 + Q2, Q2> 0) or voltage (Q1 + Q2, Q2 = 0) or the voltage when the touch is a soft touch.

In the case where the touch operation (second electrode driving, first electrode driving) is performed using the second electrode driving signal DS2 and the first electrode driving signal DS1 in the opposite phase relationship, The soft touch and the force touch can be distinguished efficiently.

Meanwhile, the touch system 100 according to the present embodiment has a unique structure for sensing the touch force. Hereinafter, a structure for touch force sensing will be described as an example.

10 is a simplified view of the touch system 100 according to the present embodiments.

10, the touch system 100 according to the present exemplary embodiment includes a plurality of first electrodes E1 disposed on a display panel 110 and a second electrode E2 disposed on an exterior of the display panel 110, And the like.

In order to sense the touch force, a gap G capable of changing the size according to the force touch must be provided between the first electrode E1 and the second electrode E2.

Accordingly, the touch system 100 according to the present exemplary embodiment may provide a gap G between the first electrode E1 and the second electrode E2 and may change the size of the gap G according to the touch force (Not shown).

Through this gap structure unit 1000, sensing for the touch force can be enabled.

11 is a view showing a display device having a force sensor structure according to the present embodiments.

Referring to FIG. 11, in a display device having a force sensor structure according to the present embodiment, a display panel 110 includes a first substrate 1110 on which a thin film transistor (TFT) And a second substrate 1120 on which a CF (Color Filter) or the like is disposed.

The driving chip 1130 may be mounted, bonded or connected to a rim portion (non-active region) of the first substrate 1110.

Here, the driving chip 1130 may be a chip implementing the touch circuit 120, a data driving chip, or a display driving chip including a touch circuit 120 and a data driving circuit.

Referring to FIG. 11, the lower structure 1100 may be positioned below the display panel 110.

The gap structure unit 1000 may be positioned below or inside the substructure 1100.

The second electrode E2 may be included under the gap structure unit 1000 or inside thereof.

Accordingly, the second electrode E2 may be positioned below or inside the lower structure 1100 of the display panel 110. [

That is, the second electrode E2 may be positioned below the lower structure 1100, which may be a backlight unit, or may be attached to the back surface of the lower structure 1100 or may be inserted into the lower structure 1100.

As described above, by designing the position of the second electrode E2, the position of the gap structure unit 1000, and the like, it is possible to implement a touch system suitable for the design structure of the display panel 110 and the display device.

Hereinafter, for convenience of description, various types of gap structure units 1000 that can be applied in a liquid crystal display device will be described by exemplifying that the display device having the force sensor structure according to the present embodiments is a liquid crystal display device . Here, the positions of the first electrode E1 and the second electrode E2 included in the liquid crystal display device will be briefly described first.

12 is a sectional view of the touch system 100 of the display device having the force sensor structure according to the present embodiments.

12 illustrates a case where a display device having a force sensor structure according to the present embodiments is a liquid crystal display device and includes a plurality of first electrodes E1 and a plurality of second electrodes E2, Fig.

12, the display panel 110 includes a first polarizer 1210, a first substrate 1110, a plurality of first electrodes E1, a second substrate 1120, a second polarizer 1220, and the like. .

On the display panel 110, a bonding layer 1230 and an upper cover 1240 are positioned.

The lower structure 1100 is positioned below the display panel 110.

The substructure 1100 may be a structure already present in the display device or a structure separately provided for the second electrode E2.

For example, the substructure 1100 can be, for example, a backlight unit of a liquid crystal display device, a back cover, and the like. In addition, it is possible to use any structure that does not disturb the electric field generated by the first electrode E1 so that a capacitor can be formed between the first electrode E1 and the second electrode E2.

The second electrode E2 may be positioned under the lower structure 1100 which may be a backlight unit or may be attached to the backside of the lower structure 1100 or inserted into the lower structure 1100 . Accordingly, a force sensor structure suitable for a liquid crystal display device can be made.

Meanwhile, in the case of the liquid crystal display device, in order to form the second capacitance C2 between the first electrode E1 and the second electrode E2, the first electrode E1 and the second electrode E2 are formed with silver (Ag), a reflective layer, a transparent electrode layer, and the like.

13 is a view showing a situation in which the size of the gap G changes due to force touch occurring in a display device having a force sensor structure according to the present embodiments.

13, when the force touch occurs, the upper cover 1240, the display panel 110, and the lower structure 1100 receive the force downward, so that the lower structure 1100, Bending down finely.

Accordingly, the size of the gap G between the lower structure 1100 and the second electrode E2 can be changed.

That is, the gap G before the force touch is generated is G1, and the gap G after the force touch is generated is G2 smaller than G1.

As described above, since the gap G is reduced from G1 to G2 before and after the force touch, the second capacitance C2 is changed and the force touch can be recognized.

As described above, some examples of the gap structure unit 1000 for allowing the size of the gap to change according to the touch force for the touch force sensing and to change the size of the gap will be described.

In one example, the gap structure unit 1000 includes a base plate made of a substrate or a film, a spacer elastic pattern (not shown) positioned between the top edge of the second electrode E2 located on the base plate and the back edge of the bottom structure 1100, And the like.

In accordance with the touch force, the upper cover 1240, the display panel 110, and the lower structure 1100 and the like receive the force downward.

Accordingly, the gap G between the base plates can be changed while the lower structure 1100 is bent downward.

As another example, the gap structure unit 1000 may include a base plate made of a substrate or a film, and an elastic sheet or the like positioned between the upper surface of the second electrode E2 positioned on the base plate and the back surface of the lower structure 1100 May be implemented.

In accordance with the touch force, the upper cover 1240, the display panel 110, and the lower structure 1100 and the like receive the force downward.

Accordingly, the gap G between the base plates can be changed while the substructure 1100 is bent.

As another example, the gap structure unit 1000 may include an upper film positioned on the back surface of the lower structure 1100, a lower film facing the upper film, a bonding film bonded to the upper surface of the lower film, A spacer located on the upper surface of the second electrode E2, and the like.

The second electrode E2 may be positioned in an inner space provided between the rear edge portion of the upper film and the upper edge portion of the lower film.

In accordance with the touch force, the upper cover 1240, the display panel 110, and the lower structure 1100 and the like receive the force downward.

Accordingly, the size of the gap G between the upper surface of the second electrode E2 and the back surface of the upper film can be changed.

As another example, the gap structure unit 1000 may be implemented with an elastic film or the like positioned between the upper surface of the second electrode E2 and the rear surface of the lower structure 1100. [

In accordance with the touch force, the upper cover 1240, the display panel 110, and the lower structure 1100 and the like receive the force downward.

Accordingly, the thickness of the elastic film may change, and the size of the gap G between the upper surface of the second electrode E2 and the rear surface of the lower structure 1100 may be changed.

As another example, the gap structure unit 1000 may be implemented including an internal pattern or the like embedded in the substructure 1100.

In accordance with the touch force, the upper cover 1240, the display panel 110, and the lower structure 1100 and the like receive the force downward.

The internal pattern of the lower structure 1100 is also subjected to a force so that the gap G between the upper surface of the second electrode E2 located at the lower portion of the lower structure 1100 and the internal pattern May vary in size.

14A and 14B are diagrams showing driving signal application circuits in a display device having a force sensor structure according to the present embodiments.

14A and 14B, a display device having a force sensor structure includes a display panel 110 having a plurality of first electrodes E1 embedded therein, a backlight unit (not shown) for providing light to the display panel 110 At least one second electrode E2 positioned outside (e.g., below) the display panel 110 and a plurality of first electrodes E1 for each of the touch driving periods, The second electrode driving signal DS2 is applied to the second electrode E2 and the reception signal is received via the first electrode E1, A touch circuit 120 sensing a touch force, and the like.

14A and 14B, the touch sensor 120 includes a first electrode E1 and a second electrode E2 serving as a force sensor, a touch circuit 120 for performing a signal transfer function and a touch force recognition function, .

Referring to FIG. 14A, the touch circuit 120 may further include a signal supply unit 1410 for generating and outputting a first electrode driving signal DS1 and a second electrode driving signal DS2.

14A, the first electrode driving signal DS1 generated and output from the signal supplying unit 1410 is supplied to the plurality of first electrodes E1 built in the display panel 110 through the driving chip 1130, As shown in FIG.

A signal transmitting member such as a printed circuit board may be provided between the signal supplying unit 1410 and the driving chip 1130 in order to transmit the first electrode driving signal DS1.

The driving chip 1130 receives the first electrode driving signal DS1 and outputs the driving signal to at least one signal line SL among the signal lines SL connected to the first electrodes E1 through a multiplexer Can be output.

Accordingly, the first electrode driving signal DS1 may be applied to the first electrode E1 disposed in the display panel 110. [

Referring to FIG. 14A, the second electrode driving signal DS2 generated and output from the signal supplying unit 1410 is supplied to a second electrode (not shown) disposed outside the display panel 110 through a signal transmitting member such as a printed circuit board E2).

As shown in FIG. 14A, when the signal supply unit 1410 generates and supplies the first electrode driving signal DS1 and the second electrode driving signal DS2 necessary for touch force sensing, the level shifter L / Since no additional parts are required, there is an advantage in that the number of parts required for the force sensor structure can be reduced.

Referring to FIG. 14B, the signal supply unit 1410 may generate and output only the first electrode driving signal DS1.

In this case, the output first electrode driving signal DS1 generated by the signal supplying unit 1410 is transmitted to the driving chip 1130 through the signal transmitting member, and the first electrode E1 embedded in the display panel 110, .

On the other hand, when the signal supply unit 1410 generates only the first electrode driving signal DS1, a separate structure for generating the second electrode driving signal DS2 may be required.

A separate structure for generating the second electrode driving signal DS2 may be implemented by a level shifter L / S as shown in Fig. 14B.

The level shifter L / S adjusts the amplitude V1 of the output first electrode driving signal DS1 generated by the signal supplying unit 1410 and outputs the adjusted voltage.

As described above, in order to sense the touch force, the amplitude V2 of the second electrode driving signal DS2 must be larger than the amplitude V1 of the first electrode driving signal DS1 (V2 > V1).

Therefore, the level shifter L / S adjusts the amplitude V1 of the first electrode driving signal DS1 to a predetermined amplitude (V2 = V1 * n) and outputs the signal having the adjusted amplitude V2 And outputs it as the two-electrode drive signal DS2.

For example, the level shifter L / S can convert the amplitude by maintaining the low level voltage of the first electrode driving signal DS1 and raising the high level voltage of the first electrode driving signal DS1.

The amplitude V2 of the second electrode driving signal DS2 output from the level shifter L / S is multiplied by n (n is a real number larger than 1) times the amplitude V1 of the first electrode driving signal DS1 .

According to the above description, since the signal supplying unit 1410 only needs to generate and supply the first electrode driving signal DS1, it is advantageous that the signal generating and supplying becomes easy.

FIG. 15 is a graph showing the intensity of a received signal RS according to the generation position of a force touch in a display device having a force sensor structure according to the present embodiments. However, it is assumed that one second electrode E2 is positioned corresponding to the entire area of the screen 1500.

Referring to FIG. 15, a change in the gap G may occur at a central point of the screen 1500 according to the structure of the second electrode E2.

Accordingly, the degree of change of the gap G varies depending on which point on the screen 1500 the user touches, that is, at what point on the screen 1500 the touch is generated, and is measured by the touch circuit 120 The signal strength of the received signal RS can be changed.

When the user presses the center point P3 on the screen 1500, the reception signal RS received by the touch circuit 120 through the first electrode E1 located at the center point P3 is the largest signal strength S3 have.

When the user presses the outer point P1 on the screen 1500, the reception signal RS received by the touch circuit 120 through the first electrode E1 located at the outer point P1 is S1 have.

When the user presses the intermediate point P2 between the center point P3 and the outer point P1 on the screen 1500, the reception signal RS received by the touch circuit 120 through the first electrode E1 located at the intermediate point P2 is S2, which is greater than S1 and less than S3.

That is, the signal intensity of the reception signal RS received by the touch circuit 120 through the first electrode E1 increases as the point at which the user depresses the screen 1500 moves to the center point P3. The signal strength of the reception signal RS received by the touch circuit 120 through the first electrode E1 may be reduced as the point at which the user depresses the screen 1500 moves to the outer point P1.

As described above, depending on which point on the screen 1500 the user presses, i.e., at what point on the screen 1500, the signal intensity variation of the received signal RS for recognizing the force touch, May occur.

The signal intensity deviation of the received signal RS may degrade the recognition accuracy of the force touch.

The signal strengths S1, S2 and S3 of the reception signal RS received through the first electrode E1 at each of the three points P1, P2 and P3 are used as a reference for the presence or absence of the touch force When the value is larger than the threshold value TH, the touches occurring at each of the three points P1, P2, and P3 can be recognized as a force touch to which a pressing force is applied.

That is, the signal intensities S1, S2, and S3 of the received signal RS received through the first electrode E1 at each of the three points P1, P2, and P3 become the criteria for the presence or absence of the touch force It can be recognized that a touch force (pressing force) is generated in each of the three points P1, P2, and P3 when the difference is larger than the threshold value TH.

However, with only one threshold value TH, it is not possible to grasp accurately whether the size of the touch force (the magnitude of the pressing force) is large or small in addition to the presence or absence of the force touch.

Even if the number of thresholds TH is set to several, the size of the touch force can not be accurately distinguished because of the signal intensity variation of the received signal RS by touch position.

Accordingly, the embodiments provide a method of preventing the signal intensity deviation of the received signal RS by touch position, and a method of using the same to grasp the size of the touch force.

16 is a diagram illustrating a processor 740 of a touch circuit 120 for compensating for a received signal variation according to the generation position of a force touch in a display device having a force sensor structure according to the present embodiments.

16, the touch circuit 120 of the display device having the force sensor structure according to the present embodiment detects the reception signal RS based on the position (corresponding to the touch position) of the first electrode E1, And the touch force can be recognized based on the corrected signal strength.

Thus, it is possible to prevent the signal intensity variation of the received signal RS according to the touch position, thereby improving the recognition accuracy of the force touch.

More specifically, the processor 740 included in the touch circuit 120 generates a first electrode driving signal DS1 (first driving signal) for a plurality of first electrodes E1 built in the display panel 110 during each touch driving period, And the second electrode driving signal DS2 is applied to at least one second electrode E2 located outside the display panel 110. The second electrode driving signal DS2 is applied to the first electrode E1 through the first electrode E1, A lookup table (LUT) for storing a correction factor (CF) for each position of the plurality of first electrodes E1, a lookup table (LUT) A signal strength corrector 1620 for correcting the signal strength of the received signal RS and a controller 1630 for recognizing the touch force based on the corrected signal strength.

As described above, by correcting the signal intensity with reference to the look-up table (LUT) prepared in advance, the signal intensity correction can be performed quickly and accurately.

FIG. 17 is a view schematically showing a look-up table (LUT) for compensating for a received signal variation according to the generation position of force touch in a display device having a force sensor structure according to the present embodiments.

Referring to FIG. 17, the look-up table (LUT) stores a correction factor (CF) for each position of a plurality of first electrodes E1.

For example, the correction coefficient for the first electrode E1 at position 1, 1 is a, the correction coefficient for the first electrode E1 at position 1, 2 is b, 1 and 3, the correction coefficient for the first electrode E1 is c. The correction coefficient for the first electrode E1 at a position corresponding to the center point among the plurality of first electrodes E1 is 1. [

Here, if the correction coefficient is 1, the signal intensities before and after the correction are the same, and the larger the correction coefficient is, the greater the signal intensity after correction than the signal intensity before correction becomes.

The signal intensity correction unit 1620 corrects the signal intensity of the first electrode E1 in the look-up table (LUT) by using a correction coefficient corresponding to the position of the first electrode E1 The corrected signal strength CF can be calculated by multiplying the extracted correction factor CF by the signal strength of the received signal RS.

That is, the corrected signal intensity can be expressed by Equation (2) below.

In Equation (2), S 'is the signal intensity after correction, S is the signal intensity before correction, and CF is a correction factor.

Here, the correction coefficient CF can be calculated by the following equation (3).

In Equation 3, CF (x, y) is a correction coefficient for the first electrode E1 at the (x, y) position, A (center) (X, y) is a preset reference signal intensity for a received signal received via the first electrode E at (x, y) position.

According to the signal intensity correction method described above, the signal intensity variation of the received signal RS according to the touch position can be accurately and efficiently removed. Thus, the recognition accuracy of the force touch can be improved.

18 is a graph illustrating a signal intensity compensated according to a result obtained by compensating for a reception signal variation according to a generation position of a force touch in a display device having a force sensor structure according to the present embodiments.

However, when the user presses the center point P3 on the screen 1500, the reception signal RS received by the touch circuit 120 through the first electrode E1 located at the center point P3 is the largest signal strength S3 , And it is assumed that the signal strength correction is not performed.

Referring to FIG. 18, it can be seen that the signal intensity deviation as shown in FIG. 15 is eliminated.

When the user presses the outer point P1 on the screen 1500, the reception signal RS received by the touch circuit 120 through the first electrode E1 located at the outer point P1 has the signal intensity of S1. The signal strength S1 is corrected to S1 '(= S1 + SL1 = S1 x P1 corresponding to E1 at the position P1) as large as? S1 according to the signal intensity correction method described above.

When the user presses the intermediate point P2 on the screen 1500, the reception signal RS received by the touch circuit 120 through the first electrode E1 located at the outer point P1 has the signal intensity of S2. The signal strength S2 is corrected to S2 '(= S2 + S2 = S2 relative to E1 at the position S2 P2) as large as? S2 according to the signal intensity correction method described above.

Accordingly, S1 'and S2' become equal to S3.

19A to 19C are views for explaining a method of finely recognizing the size of a touch force in a display device having a force sensor structure according to the present embodiments.

19A to 19C, the controller 1630 of the processor 740 of the touch circuit 120 determines whether or not the touch force is present based on the two or more predetermined threshold values TH1, TH2, and TH3 and the corrected signal intensity In addition, the strength of the touch force can be recognized in detail.

Here, the greater the number of threshold values, the more granular the touch force intensity can be recognized.

The above-described method of recognizing the segmentation according to the strength of the touch force will be exemplarily described with reference to Figs. 19A to 19C.

19A, when the corrected signal intensity Sx 'of the reception signal received through the first electrode E1 at the Px position is greater than the first threshold value TH1 and equal to or less than the second threshold value TH2 , The controller 1630 can recognize the level of the strength of the touch force as the weakest first level (L1).

Referring to FIG. 19B, when the corrected signal intensity Sy 'of the reception signal received through the first electrode E1 at the Py position is greater than the second threshold value TH2 and equal to or less than the third threshold value TH3 , The controller 1630 can recognize the level of the strength of the touch force as a second level (L2) of medium level.

Referring to FIG. 19C, when the corrected signal intensity Sz 'of the reception signal received through the first electrode E1 at the Pz position is greater than the third threshold value TH3, Can be recognized as the strongest third level (L3).

According to the above description, not only the existence of the touch force but also the strength of the touch force can be recognized in detail. Through this, it is possible to provide more various application functions.

Hereinafter, the touch force sensing method described above will be briefly described.

20 is a flowchart of a touch force sensing method of a display device having a force sensor structure according to the present embodiments.

The touch force sensing method of a display device having a force sensor structure according to the present invention is characterized in that during each touch driving period, a plurality of first electrodes E1 built in the display panel 110 are supplied with a first electrode driving signal DS1 (S2010) of applying a second electrode driving signal (DS2) to at least one second electrode (E2) located outside the display panel (110) (S2020) of receiving the received signal (RS) through the signal strength calculation unit (S2020), correcting the signal strength of the received signal (S2030), recognizing the touch force based on the corrected signal strength can do.

By using the above-described touch force sensing method, it is possible to prevent the signal intensity variation of the received signal RS according to the touch position, thereby improving the recognition accuracy of the force touch.

According to the embodiments described above, in order to provide various functions in various forms, not only sensing touch coordinates when a user generates a touch, but also sensing a touch force that the user presses the screen when touching can do.

Further, according to the embodiments, the touch force can be sensed more precisely and finely.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. , Separation, substitution, and alteration of the invention will be apparent to those skilled in the art. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and 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 construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: Touch system
110: Display panel
120: touch circuit
E1: first electrode
E2: Second electrode
740: Processor
1410:
1610: Signal receiver
1620: Signal strength correction section
1630:
LUT: lookup table

Claims (13)

A plurality of first electrodes embedded in the display panel;
At least one second electrode located outside the display panel; And
And sequentially applies a first electrode driving signal to the plurality of first electrodes and applies a second electrode driving signal to the second electrode during each touch driving period, And a touch circuit for sensing a touch force of the touch sensor,
The touch circuit includes:
And a force sensor structure for correcting the signal intensity of the received signal based on the position of the first electrode and recognizing the touch force based on the corrected signal intensity. The method according to claim 1,
The touch circuit includes:
A signal receiving unit for receiving the received signal;
A lookup table storing correction coefficients for the positions of the plurality of first electrodes;
A signal strength corrector for correcting the signal strength of the received signal by referring to the lookup table; And
And a controller for recognizing the touch force based on the corrected signal intensity. 3. The method of claim 2,
Wherein the signal strength correction unit comprises:
And a force sensor structure for extracting a correction coefficient corresponding to a position of the first electrode in the look-up table, and calculating the corrected signal intensity by multiplying the extracted correction coefficient by a signal intensity of the received signal. The method according to claim 1,
A signal supplier for outputting the first electrode driving signal; And
And a level shifter for adjusting the amplitude of the first electrode driving signal and outputting the adjusted second electrode driving signal as the second electrode driving signal. The method according to claim 1,
And a signal supply unit for outputting the first electrode driving signal and the second electrode driving signal to the first electrode and the second electrode, respectively. The method according to claim 1,
Wherein the second electrode comprises:
Wherein the force sensor structure is attached to or inserted into a back surface of a lower structure located at a lower portion of the display panel. The method according to claim 1,
Wherein the second electrode driving signal and the first electrode driving signal have the same phase. The method according to claim 1,
Wherein the second electrode driving signal has a force sensor structure having a greater signal intensity than the first electrode driving signal. The method according to claim 1,
And a force sensor structure in which a gap capable of changing the size according to the touch force exists between the plurality of first electrodes and the second electrode. 10. The method of claim 9,
The touch circuit includes:
And sequentially applies the first electrode driving signal to the plurality of first electrodes and applies the second electrode driving signal to the second electrode during the touch driving,
The method comprising: correcting a signal intensity of a received signal received from each of the plurality of first electrodes, and calculating a charge amount or a voltage according to a change in size of a gap between the plurality of first electrodes and the second electrode, And a force sensor structure for sensing the touch force. The method according to claim 1,
The touch circuit includes:
And a force sensor structure for recognizing not only the presence or absence of the touch force, but also the strength of the touch force based on the two or more predetermined threshold values and the corrected signal intensity. Applying a first electrode driving signal to a first electrode included in a display panel during each touch driving period and applying a second electrode driving signal to at least one second electrode located outside the display panel;
Receiving a received signal through the first electrode;
Correcting a signal strength of the received signal; And
And recognizing the touch force based on the corrected signal strength. A first electrode driving signal is applied to a first electrode included in a display panel during each touch driving period and a second electrode driving signal is applied to at least one second electrode located outside the display panel, A signal receiving unit for receiving a received signal through one electrode;
A signal strength correction unit for correcting a signal strength of the received signal; And
And a controller for recognizing the touch force based on the corrected signal strength.

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