Driving circuit, touch display device, and method for driving the touch display device

The present embodiments relate to a touch technology and, more particularly, to a touch display device, which includes multiple first electrodes embedded in a display panel, at least one second electrode positioned outside the display panel, and a touch force sensing gap existing between the multiple first electrodes and the at least one second electrode, a method for driving the same, and a driving circuit for driving the multiple first electrodes and the at least one second electrode. The present embodiments, as described above, make it possible to sense not only a touch position, but also a touch force, with which the user presses the screen during a touch.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No. 10-2015-0127300, filed on Sep. 8, 2015, Korean Patent Application No. 10-2016-0034127, filed on Mar. 22, 2016, and U.S. patent application Ser. No. 14/985,032, filed on Dec. 30, 2015, which are hereby incorporated by reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present embodiments relate to a driving circuit, a touch display device, and a method for driving the same.

2. Description of the Prior Art

Development of information-oriented societies has been increasing various kinds of demands for display devices for displaying images, and various types of display devices have been used, such as a liquid crystal display device, a plasma display device, and an organic light-emitting display device.

Among the display devices, furthermore, mobile devices, such as smart phones and tablets, and medium/large-sized devices, such as smart televisions, provide touch-type input processing according to user convenience, device characteristics, and the like.

Display devices capable of such touch input processing are evolving to provide more diversified functions, and user demands are also becoming more diversified.

However, the currently applied type of touch input processing, in which the user's touch position (touch coordinate) is solely sensed and relevant input processing is performed in the sensed touch position, has its limitations in the current situation which requires provision of many functions of various kinds and satisfaction of various user demands.

SUMMARY OF THE INVENTION

An aspect of the present embodiments is to provide a touch display device, a method for driving the same, and a driving circuit, the touch display device being structured such that it cannot only sense the coordinate (position) of a touch generated by the user, but also sense the touch force, with which the user presses the screen during the touch, in order to provide various functions in various types.

Another aspect of the present embodiments is to provide a driving circuit, a touch display device, and a method for driving the same, which enable simultaneous proceeding of driving for sensing a touch position and driving for sensing a touch force during a touch mode period.

Another aspect of the present embodiments is to provide a driving circuit, a touch display device, and a method for driving the same, which enable separate proceedings of driving for sensing a touch position and driving for sensing a touch force during a touch mode period.

Another aspect of the present embodiments is to provide a driving circuit, a touch display device, and a method for driving the same, which can recognize the position of occurrence of a touch force, i.e. a force with which the user's touch presses the screen.

Another aspect of the present embodiments is to provide a driving circuit, a touch display device, and a method for driving the same, which can accurately distinguish between a soft touch, i.e. the force with which the user's touch presses the screen does not exist or is equal to or less than a predetermined level, and a force touch, i.e. the force with which the user's touch presses the screen exists or exceeds the predetermined level.

Another aspect of the present embodiments is to provide a touch display device including a display panel, on which multiple first electrodes are arranged, a second electrode positioned outside the display panel, and a touch force sensing gap, which exists between the multiple first electrodes and the second electrode, and which can change its size according to a touch force such that touch force sensing is possible.

According to an aspect, the present embodiments may include a touch display device including: multiple first electrodes embedded in a display panel; at least one second electrode positioned outside the display panel; and at least one touch force sensing gap existing between the multiple first electrodes and the second electrode such that a capacitor is formed between the multiple first electrodes and the second electrode.

In connection with such a touch display device, the touch force sensing gap is variable according to a touch force of a touch applied to the display panel.

According to another aspect, the present embodiments may provide a method for driving a touch display device, including: driving a display panel during a display mode period; and successively applying a first electrode driving signal to at least one of multiple first electrodes, which are embedded in the display panel, during a touch mode period and simultaneously applying a second electrode driving signal to a second electrode, which is positioned outside the display panel, such that a touch position and a touch force are simultaneously sensed with regard to a single touch.

According to another aspect, the present embodiments may provide a driving circuit including: a signal generating circuit configured to generate and output a first electrode driving signal; a first electrode driving circuit configured to apply a display driving voltage to multiple first electrodes, which are embedded in a display panel, during a display mode period and to successively apply the first electrode driving signal to at least one of the multiple first electrodes during a touch mode period; and a second electrode driving circuit configured to apply a second electrode driving signal to a second electrode, which is positioned outside the display panel, during the touch mode period.

According to another aspect, the present embodiments may provide a method for driving a touch display device, including: driving a display panel during a display mode period; successively applying a touch driving signal to at least one of multiple first electrodes, which are embedded in the display panel, during a touch driving period, thereby sensing a touch position with regard to a touch; and applying a first force driving signal to all or some of the multiple first electrodes, during a force driving period, and simultaneously applying a second force driving signal to the second electrode, thereby sensing a touch force with regard to the touch.

According to another aspect, the present embodiments may provide a driving circuit including: a signal generating circuit configured to generate and output a touch driving signal and a first force driving signal; a first electrode driving circuit configured to apply a display driving voltage to multiple first electrodes, which are embedded in a display panel, during a display mode period, configured to successively apply the touch driving signal to at least one of the multiple first electrodes during a touch driving period, configured to receive an input of the first force driving signal during a force driving period, and configured to apply the first force driving signal to all or some of the multiple first electrodes; and a second electrode driving circuit configured to apply a second force driving signal to a second electrode, which is positioned outside the display panel, during the force driving period.

According to another aspect, the present embodiments may provide a driving circuit configured to apply a display driving voltage to multiple first electrodes, which are embedded in a display panel, during a display mode period, configured to successively apply a touch driving signal to at least one of the multiple first electrodes during a touch driving period, and configured to apply a first force driving signal to all or some of the multiple first electrodes during a force driving period.

As described above, the present embodiments may provide a touch display device, a method for driving the same, and a driving circuit, the touch display device being structured such that it cannot only sense the coordinate (position) of a touch generated by the user, but also sense the touch force, with which the user presses the screen during the touch, in order to provide various functions in various types.

The present embodiments may provide a driving circuit, a touch display device, and a method for driving the same, which enable simultaneous proceeding of driving for sensing a touch position and driving for sensing a touch force during a touch mode period.

The present embodiments may provide a driving circuit, a touch display device, and a method for driving the same, which enable separate proceedings of driving for sensing a touch position and driving for sensing a touch force during a touch mode period.

The present embodiments may provide a driving circuit, a touch display device, and a method for driving the same, which can recognize the position of occurrence of a touch force, i.e. a force with which the user's touch presses the screen.

The present embodiments may provide a driving circuit, a touch display device, and a method for driving the same, which can accurately distinguish between a soft touch, i.e. the force with which the user's touch presses the screen does not exist or is equal to or less than a predetermined level, and a force touch, i.e. the force with which the user's touch presses the screen exists or exceeds the predetermined level.

The present embodiments may provide a touch display device including a display panel, on which multiple first electrodes are arranged, a second electrode positioned outside the display panel, and a touch force sensing gap, which exists between the multiple first electrodes and the second electrode, and which can change its size according to a touch force such that touch force sensing is possible.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Hereinafter, some embodiments of the present invention will be described in detail with reference to the accompanying illustrative drawings. In designating elements of the drawings by reference numerals, the same elements will be designated by the same reference numerals although they are shown in different drawings. Further, 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 addition, terms, such as first, second, A, B, (a), (b) or the like may be used herein when describing components of the present invention. Each of these terminologies is not used to define an essence, order or sequence of a corresponding component but used merely to distinguish the corresponding component from other component(s). In the case that it is described that a certain structural element “is connected to”, “is coupled to”, or “is in contact with” another structural element, it should be interpreted that another structural element may be connected to”, “be coupled to”, or “be in contact with” the structural elements as well as that the certain structural element is directly connected to or is in direct contact with another structural element.

FIG. 1is a diagram illustrating a schematic configuration of a touch display device100according to the present embodiments, andFIG. 2is a diagram illustrating an operation mode of the touch display device100according to the present embodiments.

Referring toFIG. 1andFIG. 2, the touch display device100according to the present embodiments may operate in a display mode for displaying images, or may operate in a touch mode for sensing the user's touch.

The touch display device100according to the present embodiments, when operating in the display mode, drives data lines and gate lines, which are arranged on a display panel110, thereby displaying images.

The touch display device100according to the present embodiments, when operating in the touch mode, cannot only provide a touch position sensing function, with regard to a touch generated by a finger, a pen, or the like, for determining whether a touch has occurred or not and for sensing the touch position, but can also provide a touch force sensing function for sensing a touch force (also simply referred to as “a force”), which corresponds to the force (pressure) applied during the touch.

As used in the present specification, a touch refers to an action of the user contacting the display panel110by a pointer.

Such touches may be classified into soft touches, i.e. the force (pressure) with which the display panel110is pressed is absent or is equal to or less than a predetermined level, and force touches, i.e. the force (pressure) with which the display panel110is pressed exists or exceeds the predetermined level.

A touch position (also referred to as “a touch coordinate”) resulting from such a touch (soft touch or force touch) refers to the position of the point at which the user has touched the display panel110.

In addition, a touch force resulting from such a touch (force touch) refers to the force (pressure) with which the user presses the display panel110during the touch.

On the other hand, the pointer by which the user touches the screen may be a part of the human body, such as a finger, or a conductor point, such as a pen having a contact portion made of a conductor, and, in some cases, may be a nonconductor pointer, such as a pen having a contact portion made of a nonconductor.

A pointer for enabling sensing of a touch position needs to be a conductor pointer. In contrast, a pointer for enabling sensing of a touch force may be either a conductor pointer or a nonconductor pointer.

Referring toFIG. 1andFIG. 2, the touch display device100according to the present embodiments may include multiple first electrodes E1, which are necessary to sense a touch position (which is a concept including whether a touch occurs or not), a second electrode E2for sensing a touch force, a driving circuit120for driving the multiple first electrodes E1and the second electrode E2, thereby sensing a touch position and a touch force, and the like.

The multiple first electrodes E1are electrodes used to sense a touch position, and are also referred to as “touch sensors” or “touch electrodes”.

The multiple first electrodes E1may be arranged on a touch screen panel, which is separate from the display panel110, or may be embedded and arranged in the display panel110.

When the multiple first electrodes E1are embedded and arranged in the display panel110, the display panel110may be referred to as “a touch screen panel-integrated display panel”, which has multiple first electrodes E1embedded therein.

On the other hand, the second electrode E2is an electrode used to sense a touch force, which corresponds to a force (pressure) applied during a touch.

The second electrode E2may be positioned on the outer portion (for example, lower portion, upper portion, side surface, or the like) of the display panel110.

On the other hand, the touch display device100according to the present embodiments may successive drive the multiple electrodes E1, in order to sense a touch position, and may grasp a change in capacitance between each first electrode E1and the pointer on the basis of a signal received from each first electrode E1, thereby sensing a touch position.

In order to sense a touch force, in contrast, the touch display device100according to the present embodiments needs to drive the multiple first electrodes E1and the second electrode E2simultaneously.

In other words, in order to sense a touch position, the driving circuit120of the touch display device100according to the present embodiments successively applies a first electrode driving signal DS1to the multiple first electrodes E1, thereby successively driving the multiple first electrodes E1.

In the present specification, the first electrode driving signal DS1, which is applied to the first electrodes E1in order to sense a touch position, is also referred to as “a touch driving signal TDS”.

In order to sense a touch force, furthermore, the driving circuit120of the touch display device100according to the present embodiments applies a first electrode driving signal DS1to the multiple first electrodes E1and simultaneously applies a second electrode driving signal DS2to the second electrode E2, thereby driving the multiple first electrodes E1and the second electrode E2simultaneously.

In the present specification, the first electrode driving signal DS1, which is applied to the first electrodes E1in order to sense a touch force, is also referred to as “a first force driving signal FDS1”, and the second electrode driving signal DS2, which is applied to the second electrode E2, is also referred to as “a second force driving signal FDS2”.

Given that the multiple first electrodes E1and the second electrode E2are driven simultaneously in order to sense a touch force, the multiple first electrodes E1, which are embedded in the display panel110, and the second electrode E2, which is positioned on the outer portion of the display panel110, may be referred to as “a force sensor” as a whole.

On the other hand, the multiple first electrodes E1can not only operate as a touch sensor and a force sensor during a touch mode period, but can also operate as a kind of display driving electrodes, to which a display driving voltage is applied, during a display mode period.

For example, the multiple first electrodes E1may be common electrodes, to which a common voltage Vcom is applied, during a display mode period, the common voltages Vcom corresponding to a display driving voltage.

When the multiple first electrodes E1are also used as display driving electrodes as such, the multiple first electrodes E1play triple roles of a touch sensor, a force sensor, and display driving electrodes.

FIG. 3andFIG. 4are diagrams illustrating a principle of sensing by a touch display device100according to the present embodiments.

FIG. 3is a diagram illustrating sensing operations in connection with three touch types (Case1, Case2, and Case3) according to the kind of the pointer and whether a touch force exists or not, andFIG. 4is a diagram illustrating a sensing principle according to the three touch types.

Referring toFIG. 3, the touch types may include Case1that corresponds to a soft touch, which is generated by a pointer that has a contact portion made of a conductor, and which is generated by a pressing force equal to or less than a predetermined level; Case2that corresponds to a force touch, which is generated by a pointer that has a contact portion made of a conductor, and which is generated by a force that exceeds the predetermined level; and Case3that corresponds to a force touch, which is generated by a pointer that has a contact portion made of a nonconductor, and which is generated by a force that exceeds the predetermined level.

Referring toFIG. 3andFIG. 4, the driving circuit120successively applies a first electrode driving signal DS1to the multiple first electrodes E1, during a touch mode period, and applies a second electrode driving signal DS2to the second electrode E2, thereby performing driving for sensing a touch position and a touch force.

According to the driving by the driving circuit120during the touch mode period, a first capacitance C1may be formed between the first electrodes E1and the pointer that corresponds to the first type, or a second capacitance C2may be formed between the first electrodes E1and the second electrode E2.

The first capacitance C1formed between the first electrodes E1and the pointer may vary according to whether a touch is generated or not.

The second capacitance C2formed between the first electrodes E1and the second electrode E2may vary according to whether a touch force exists or not (magnitude thereof).

Therefore, the driving circuit120may grasp a change in magnitude of the first capacitance C1, on the basis of signals received from respective first electrodes E1, and a change in magnitude of each second capacitance C2, may sense a touch position on the basis of the change in magnitude of the first capacitance C1, and may sense a touch force on the basis of the change in magnitude of the second capacitance C2.

Referring toFIG. 3andFIG. 4, the touch display device100may be structured, in order to enable a touch force sensing, such that a capacitor is formed between the multiple first electrodes E1and the second electrode E2, and at least one touch force sensing gap G, which can change its size according to whether a touch force exists or not, exists between the multiple first electrodes E1and the second electrode E2.

In this regard, the touch force sensing gap G may be, for example, a dielectric substance gap or an air gap. Hereinafter, the touch force sensing gap G will be simply referred to as a “gap G”.

When a force touch occurs at a point, the size of the touch force sensing gap G varies in the vertical direction. This changes the magnitude of the second capacitance C2between the first electrodes E1and the second electrode E2, and it is possible to perform a touch force sensing function of sensing a touch force on the basis of such a change in magnitude of the second capacitance C2.

In this regard, the result of touch force sensing may include information regarding whether a touch force exists or not, and may include information regarding the magnitude of the touch force.

As described above, structurally providing a touch force sensing gap G, which can change its size, between the first electrodes E1and the second electrode E2enables touch force sensing.

The touch display device100according to the present embodiments can sense a touch force in a capacitance type, in the same manner of sensing a touch position (touch coordinate).

In other words, the touch display device100according to the present embodiments is peculiar in that, in order to sense a touch force (pressing force) of a touch, the same does not solely employ a dedicated pressure sensor as in the conventional pressure sensing scheme, but uses both the second electrode E2, which is positioned on the outer portion of the display panel110for the purpose of touch force sensing, and the multiple first electrodes E1, which are embedded in the display panel110for the purpose of touch coordinate calculation, thereby sensing a touch force in a capacitance type.

As described above, even if the driving circuit120drives the first electrodes E1and the second electrode E2in the same manner during a touch mode period, the sensed information may differ depending on the touch type.

For example, in connection with Case1illustrated inFIG. 3andFIG. 4, in the case of a first touch type corresponding to a soft touch, which is generated by a pointer that has a contact portion made of a conductor, and which is generated by a pressing force equal to or less than a predetermined level, the driving circuit120, after driving the first electrodes E1and the second electrode E2, may solely sense a touch position, with regard to the touch, on the basis of a signal received from each first electrode E1.

This is because, in the case of a first touch type corresponding to a soft touch, which is generated by a pointer that has a contact portion made of a conductor, and which is generated by a pressing force equal to or less than a predetermined level, there occurs a change in magnitude of the first capacitance C1with the pointer for each first electrode E1, but there occurs no change in magnitude of the second capacitance C2between the first electrodes E1and the second electrode E2, making it possible to sense a touch position only.

As another example, in connection with Case2illustrated inFIG. 3andFIG. 4, in the case of a first touch case corresponding to a soft touch, which is generated by a pointer that has a contact portion made of a conductor, and which is generated by a pressing force equal to or less than a predetermined level, the driving circuit120can simultaneously sense a touch position and a touch force, with regard to the touch, on the basis of a signal received from each first electrode E1.

This is because, in the case of the second touch type corresponding to a force touch, which is generated by a pointer that has a contact portion made of a conductor, and which is generated by a pressing force exceeding a predetermined level, there occurs a change in magnitude of the first capacitance C1with the pointer for each first electrode E1, and there also occurs a change in magnitude of the second capacitance C2between the first electrodes E1and the second electrode E2, making it possible to sense both a touch position and a touch force with regard to a single touch.

As another example, in connection with Case3illustrated inFIG. 3andFIG. 4, in the case of a third touch type corresponding to a force touch, which is generated by a pointer that has a contact portion made of a nonconductor, and which is generated by a pressing force that exceeds the predetermined level, the driving circuit120can solely sense a touch force, with regard to the touch, on the basis of a signal received from each first electrode E1.

This is because, in the case of the third touch type corresponding to a force touch, which is generated by a pointer that has a contact portion made of a nonconductor, and which is generated by a pressing force that exceeds the predetermined level, there occurs no change in the first capacitance C1with the pointer for each electrode E1, but there occurs a change in magnitude of the second capacitance C2between the first electrodes E1and the second electrode E2, making it possible to solely sense a touch force only with regard to a single touch.

As described above, the touch display device100has a gap structure between the first electrodes E1and the second electrode E2, and performs sensing processing on the basis of signals received through the first electrodes E1; as a result, even if the first electrodes E1and the second electrode E2are driven in the same manner during a touch mode period, regardless of the kind of the touch type, and even if signal detection and sensing processing are performed in the same manner, it is possible to obtain sensing information conforming to the touch type.

Hereinafter, a first electrode driving signal DS1and a second electrode driving signal DS2, which are for the purpose of touch driving during a touch mode period, will be described.

The first electrode driving signal DS1, which is applied to the first electrodes E1during a touch mode period, may be regarded as a touch driving signal in terms of a touch sensing function for sensing a touch position, and may also be regarded as a force driving signal in terms of a force sensing function for sensing a touch force.

The second electrode driving signal DS2, which is applied to the second electrode E2during the touch mode period, may be regarded as a force driving signal in terms of a force sensing function for sensing a touch force.

During a touch mode period, during which the touch display device100according to the present embodiments operates in a touch mode, the touch position and the touch force may be sensed simultaneously or may be sensed independently through driving in different periods, respectively.

FIG. 5illustrate exemplary first electrode driving signals DS1for driving the first electrodes E1, in connection with a touch display device100according to the present embodiments, andFIG. 6illustrates exemplary second electrode driving signals DS2for driving the second electrode E2, in connection with the touch display device100according to the present embodiments.

Referring toFIG. 5, the first electrode driving signal DS1may be a pulse-type signal having a predetermined frequency, a predetermined amplitude, and a predetermined phase, and may be a signal having a DC voltage.

When the first electrode driving signal DS1is a pulse-type signal, the amplitude thereof may be a first voltage V1.

When the first electrode driving signal DS1is a signal having a DC voltage, the DV voltage may be a ground voltage GND or a first reference voltage Vref1, which is not the ground voltage GND. In this regard, the first reference voltage Vref1may be, for example, a common voltage Vcom.

Referring toFIG. 6, the second electrode driving signal DS2may be a pulse-type signal having a predetermined frequency, a predetermined amplitude, and a predetermined phase, and may be a signal having a DC voltage.

When the second electrode driving signal DS2is a pulse-type signal, the amplitude thereof may be a second voltage V2.

The frequency of the second electrode driving signal DS2is identical to the frequency of the first electrode driving signal DS1.

However, the phase of the second electrode driving signal DS2may be identical to the phase of the first electrode driving signal DS1, or may have a phase difference of 180°.

When the first electrode driving signal DS1and the second electrode driving signal DS2have the same phase, the first electrode driving signal DS1and the second electrode driving signal DS2are described as having an equiphase relationship.

When the first electrode driving signal DS1and the second electrode driving signal DS2have a phase difference of 180°, the first electrode driving signal DS1and the second electrode driving signal DS2are described having a reverse-phase relationship.

When the first electrode driving signal DS1is a signal having a DC voltage, the DV voltage may be a ground voltage GND or a second reference voltage Vref2, which is not the ground voltage GND. In this regard, the second reference voltage Vref2may be, for example, a common voltage Vcom.

The first reference voltage Vref1and the second reference voltage Vref2may be identical or different.

It is possible to properly combine and use the exemplary first electrode driving signals DS1and the second electrode driving signals DS2, which are illustrated inFIG. 5andFIG. 6, according to the driving scheme in the touch mode period.

FIG. 7is a diagram illustrating a driving circuit120of the touch display device100according to the present embodiments.

As illustrated inFIG. 7, the driving circuit120may include a first electrode driving signal supply unit710, a second electrode driving signal supply unit720, an integrator730, and the like.

The first electrode driving signal supply unit710may supply a first electrode driving signal DS1, which has one of signal waveforms illustrated inFIG. 5, to a first electrode E1through on-off control of two switches SW1and SW10.

The second electrode driving signal supply unit720may supply a second electrode driving signal DS2, which has one of signal waveforms illustrated inFIG. 6, to a second electrode E2through on-off control of two switches SW2and SW20.

The integrator710may include an operation amplifier OP-AMP, a capacitor C, a resistor R, and the like, and may output an integration value with regard to an input of an input stage, which is electrically connected to the first electrode E1.

The driving circuit120may further include an analog-digital converter ADC configured to convert the output value from the integrator730to a digital value, a processor740configured to perform touch position calculation, touch force recognition, and the like on the basis of the digital value output from the analog-digital converter ADC, and the like.

In this regard, at least one of the analog-digital converter ADC and the processor740may be positioned outside the driving circuit120.

The circuit configuration of the driving circuit120illustrated inFIG. 7is only an example for convenience in description, and may be implemented in various other types.

Referring toFIG. 7, the driving circuit120applies a first electrode driving signal DS1to the first electrode E1during driving in the touch mode period, applies a second electrode driving signal DS2to the second electrode E2, and then converts a value Vsen, which is obtained by integrating a signal received from the first electrode E1through the integrator730, to a digital value.

It is possible to sense at least one of a touch position and a touch force by grasping the amount of charging (or voltage) or a change thereof, which depends on whether a touch exists or not, whether a touch force exists or not, and the like, on the basis of the digital value with regard to each first electrode E1.

Referring toFIG. 7, the signal (input to the integrator730) received from the first electrode E1corresponds to the combined amount of electrical charges Q1+Q2that is the sum of the amount of electrical charge Q1, which charges the capacitor between the pointer and the first electrode E1, and the amount of electrical charge Q2, which charges the capacitor between the first electrode E1and the second electrode E2.

Depending on driving in the touch mode period, the amount of electrical charge Q1, which charges the capacitor between the pointer and the first electrode E1, may be determined by the first capacitance C1and by the voltage V1of the first electrode driving signal DS1. The amount of electrical charge Q2, which charges the capacitor between the first electrode E1and the second electrode E2, may be determined by the second capacitance C2, by the voltage V1of the first electrode driving signal DS1, and by the voltage V2of the second electrode driving signal DS2.

The amount of electrical charge Q1, which charges the capacitor between the pointer and the first electrode E1, and the amount of electrical charge Q2, which charges the capacitor between the first electrode E1and the second electrode E2, may be expressed by equation (1) below:
Q1=C1×V1
Q2=C2×(V1−V2)  Equation (1)

The combined amount of electrical charges Q1+Q2charges the capacitor C inside the integrator730, and is output from the integrator730as a sensing voltage value Vsen.

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

The processor740may sense at least one of the touch position and the touch force on the basis of the digital value (sensing value) output from the analog-digital converter ADC.

On the other hand, when a touch force is sensed, a predetermined application or a function may be executed so as to correspond to the touch force.

Alternatively, when a touch force is sensed, a predetermined application or a function may be executed so as to correspond to the magnitude of the touch force.

FIG. 8is a diagram illustrating the intensity of a received signal, which results from a soft touch, and the intensity of a received signal, which results from a force touch, in connection with a touch display device100according to the present embodiments.

It has been assumed in connection withFIG. 8that the first electrode driving signal DS1and the second electrode driving signal DS2are pulse-type signals as illustrated inFIG. 6AandFIG. 6B.

Referring toFIG. 8, the signal intensity of a signal received from the first electrode E1can be confirmed from a digital value output from the analog-digital converter ADC.

Referring toFIG. 8, a digital value output from the analog-digital converter ADC when the pressing force does not exist or is equal to or less than a predetermined level has a value in the positive (+) direction, with reference to a digital value output from the analog-digital converter ADC when there is no touch at all (baseline).

Referring toFIG. 8, assuming that the first electrode driving signal DS1and the second electrode driving signal DS2have an equiphase relationship, a digital value output from the analog-digital converter ADC when a pressing force generated by a pointer having a contact portion made of a nonconductor exists or exceeds a predetermined level (i.e. when a force touch occurs) has a value in the negative (−) direction with reference to the baseline.

Referring toFIG. 8, assuming that the first electrode driving signal DS1and the second electrode driving signal DS2have a reverse-phase relationship, a digital value output from the analog-digital converter ADC when a pressing force generated by a pointer having a contact portion made of a nonconductor exists or exceeds a predetermined level (i.e. when a force touch occurs) has a value in the positive (+) direction with reference to the baseline.

FIG. 9AandFIG. 9Bare diagrams illustrating the distribution of the intensity of a received signal, which results from a soft touch, and the intensity of a received signal, which results from a force touch, in connection with a touch display device100according to the present embodiments.

FIG. 9AandFIG. 9Bare diagrams illustrating the distribution of the intensity of a received signal, which results from a soft touch, and the intensity of a received signal, which results from a force touch, in the entire area (XY plane) of a touch display device100according to the present embodiments.

Referring toFIG. 9A, in view of the entire area of the display panel110, when a soft touch occurs at a specific point, the magnitude of the digital value output from the analog-digital converter ADC (signal intensity) has such an overall distribution, with reference to the baseline, that the signal intensity increases in the positive (+) direction of z-axis.

In connection with the signal intensity distribution when a soft touch occurred, furthermore, a large signal intensity may be distributed and concentrated at the point, at which the soft touch occurred, among the entire area of the screen (entire area of the display panel110).

Referring toFIG. 9B, on the other hand, assuming that the second electrode E2is a single plate electrode type, when a force touch occurs, the magnitude of the digital value output from the analog-digital converter ADC (signal intensity) has such an overall distribution that, with reference to the baseline, the signal intensity increases in the negative (−) direction of z-axis.

When a force touch occurred, furthermore, the distribution is as follows: the signal intensity is largest in the negative (−) direction at the screen center point, but the signal intensity has a gradual increase, starting from the outer periphery of the screen, towards the center point.

On the other hand, the stronger the force touch is, the larger the change in size of the gap G between the multiple first electrodes E1and the second electrode E2; accordingly, the digital value output from the analog-digital converter ADC has a larger value in the negative (−) direction of z-axis with reference to the baseline. That is, the signal intensity increases in proportion to the intensity of the force touch.

FIG. 10andFIG. 11are diagrams schematically illustrating a touch display device100according to the present embodiments.

Referring toFIG. 10, the touch display device100according to the present embodiments includes multiple first electrodes E1, which are arranged on a display panel110, a second electrode E2, which is positioned on the outer portion of the display panel110, and the like.

In order to sense a touch force, a gap G, which can change its size according to a force touch, needs to be provided between the multiple first electrodes E1and the second electrode E2.

In order to generate a change in size of the gap G, which exists between the multiple first electrodes E1and the second electrode E2, when a force touch occurs, the touch display device100according to the present embodiments may include a gap structure unit1000, which generates a gap G between the multiple electrodes E1and the second electrode E2, and which enables a change in size of the gap G according to a touch force.

Such a gap structure unit1000may be positioned beneath the display panel110, for example, and may support the edge portion of the display panel110.

Such a gap structure unit1000enables a change in size of the gap G between the multiple first electrodes E1and the second electrode E2, when a force touch occurs, thereby enabling sensing of a touch force.

Referring toFIG. 11, the display panel110of the touch display device100according to the present embodiments may include a first substrate1110, on which a TFT (Thin Film Transistor) and the like are arranged, and a second substrate1120, on which a CF (Color Filter) and the like are arranged.

In addition, a driving chip1130may be mounted, bonded, or connected to the edge portion (non-active area) of the first substrate1110.

In this regard, the driving chip1130may be a chip that implements all or part of the driving circuit1200, may be a data driving chip, and, in some cases, may be a display driving chip that includes all or part of the data driving circuit and the driving circuit120.

Referring toFIG. 11, a lower structure1100may be positioned beneath the display panel110.

The second electrode E2may be positioned beneath or inside the lower structure1100.

The lower structure1100may be, for example, a backlight unit of a liquid crystal display device. In this case, the second electrode E2may be positioned beneath the backlight unit.

This makes it possible to arrange the second electrode E2without interfering with the light emitting function of the backlight unit.

The gap structure unit1000may be positioned beneath, inside, or on a side surface of the lower structure1000.

In addition, the second electrode E2may be positioned beneath or inside the gap structure unit1000.

Various designs of the position of the second electrode E2or the position of the gap structure unit1000, as described above, make it possible to implement a touch force sensing structure suitable for the design structure of the display panel110and that of the touch display device100.

Various types of gap structure units1000, which can be applied to a liquid crystal device, will hereinafter be described assuming, for convenience of description, that a touch display device1000according to the present embodiments is a liquid crystal display device. In this connection, the positions of a first electrode E1and of a second electrode E2, which are included in the touch display device100, will be briefly described first.

FIG. 12is a sectional diagram of a touch display device100according to the present embodiments.

Referring toFIG. 12, the display panel110includes a first polarization plate1210, a first substrate1110, multiple first electrodes E1, a second substrate1120, a second polarization plate1220, and the like.

A bonding layer1230and an upper cover1240are positioned on the display panel110.

A lower structure1100is positioned beneath the display panel110.

The lower structure1100may be a structure already existing in the touch display device100, or a structure separately provided for the second electrode E2.

The lower structure1100, for example, may be a backlight unit, a back cover, or the like of the liquid crystal display device. Besides, any structure is possible as long as it does not interfere with the electric field generated from the first electrodes E1such that a capacitor can be formed between the first electrodes E1and the second electrode E2.

Positioning the second electrode E2beneath or inside the lower structure1100, which corresponds to a backlight unit, as described above, can implement a force sensing structure adapted to the liquid crystal display device.

On the other hand, in the case of a liquid crystal display device, materials that interfere with formation of a second capacitance C2between the first electrodes E1and the second electrode E2(for example, a layer of material such as silver (Ag), a reflection plate, a transparent electrode layer, and the like) should not exist.

Various examples of gap structure units1000will hereinafter be described.

FIG. 13toFIG. 18are diagrams illustrating examples of a gap structure unit1000of a touch display device100according to the present embodiments and changes in the gap size when a touch force occurs.

Referring toFIG. 13, the gap structure unit1000may include a base plate1310made of a substrate or a film, a spacer elastic pattern1320positioned between the upper surface edge of a second electrode E2, which is positioned on the base plate1310, and the rear surface edge of a lower structure1100, and the like.

The spacer elastic pattern1320may be attached, bonded, or coated on the rear surface of the lower structure1100.

The spacer elastic pattern1320is made of an elastic material.

Referring toFIG. 13, when a force touch occurs, the upper cover1240, the display panel110, the lower structure1100, and the like receive a downward force.

Accordingly, the touch force may change the size of the gap G between the non-edge portion of the upper surface of the second electrode E2and the non-edge portion of the rear surface of the lower structure1100.

Particularly, the gap G before occurrence of the force touch is G1, and the gap G after occurrence of the touch force is G2, which is smaller than G1.

Such a decrease of the gap G from G1to G2, before and after occurrence of a force touch, changes the second capacitance C2and enables recognition of the force touch.

The gap structure unit1000ofFIG. 13can increase the gap change and does not require modification of existing structures, such as the display panel110and the lower structure1100, making it possible to easily implement a touch display device100capable of efficient force touch sensing.

Referring toFIG. 14, the gap structure unit1000may include a base plate1310made of a substrate or a film, an elastic sheet1400positioned between the upper surface of a second electrode E2, which is positioned on the base plate1310, and the rear surface of a lower structure1100, and the like.

The elastic sheet1400may be attached, bonded, or coated on the rear surface of the lower structure1100.

Referring toFIG. 14, when a force touch occurs, the upper cover1240, the display panel110, the lower structure1100, and the like receive a downward force.

Accordingly, the touch force of the touch changes the thickness of the elastic sheet, and the size of the G between the upper surface of the second electrode E2and the rear surface of the lower structure1100may change as a result.

Particularly, the gap G before occurrence of the force touch is G1, and the gap G after occurrence of the touch force is G2, which is smaller than G1.

Such a decrease of the gap G from G1to G2, before and after occurrence of a force touch, changes the second capacitance C2and enables recognition of the force touch.

The gap structure unit1000ofFIG. 14can be implemented to be thinner, and does not require modification of existing structures, such as the display panel110and the lower structure1100, making it possible to easily implement a touch display device100capable of efficient force touch sensing with no significant change in size thereof.

Referring toFIG. 15, the gap structure unit1000may include an upper film1520positioned on the rear surface of a lower structure1100, a lower film1510facing the upper film1520, a bonding agent1530bonded to the rear surface edge of the upper film1520and to the upper surface edge of the lower film1510, and the like.

Referring toFIG. 15, a second electrode E2may be positioned in an internal space provided by spacing between the non-edge portion of the rear surface of the upper film1520and the non-edge portion of the upper surface of the lower film1510.

Referring toFIG. 15, a spacer1540may exist on the upper surface of the second electrode E2.

Referring toFIG. 15, when a force touch occurs, the upper cover1240, the display panel110, the lower structure1100, and the like receive a downward force.

Accordingly, the size of the G between the upper surface of the second electrode E2and the rear surface of the upper film1520may change according to the touch force of the touch.

Particularly, the gap G before occurrence of the force touch is G1, and the gap G after occurrence of the touch force is G2, which is smaller than G1.

Such a decrease of the gap G from G1to G2, before and after occurrence of a force touch, changes the second capacitance C2and enables recognition of the force touch.

The spacer1540is made of a material that has elasticity, in order to sense a touch force, and can be pressed by an external force and then can be restored.

In addition, the spacer1540prevents the upper film1520(or the lower structure1100) and the second electrode E2from directly contacting each other, and prevents the second electrode E2from being deformed even when pressed by an external force (force touch).

This may cause a change in size of the gap G between the upper film1520and the second electrode E2(G1→G2).

Furthermore, the spacer1540may be made of a conductive material or a nonconductive material.

It is possible to configure the gap structure unit1000solely by the spacer1540.

On the other hand, with regard to the same force touch, the larger the change in size of the gap G at the center point, the higher the sensing sensitivity related to the touch force can be.

In this connection, if the change in gap size at the edge is removed, the change in gap size at the center point can become larger.

To this end, the gap structure unit1000may additionally include a lower film1510, a bonding agent1530, and the like.

The gap structure unit1000ofFIG. 15is implemented in a module type such that, without modifying existing structures such as the display panel110, the lower structure1100, and the like, the module-type gap structure unit1000can be attached beneath the lower structure1100. This is advantageous in that the gap structure unit1000can be easily included in the touch display device and fabricated as such.

Referring toFIG. 16, the gap structure unit1000may include an elastic film1600positioned between the upper surface of a second electrode E2and the rear surface of a lower structure1100, and the like.

Referring toFIG. 16, when a force touch occurs, the upper cover1240, the display panel110, the lower structure1100, and the like receive a downward force.

Accordingly, the touch force of the touch changes the thickness of the elastic film, and the size of the G between the upper surface of the second electrode E2and the rear surface of the lower structure1100may change as a result.

Particularly, the gap G before occurrence of the force touch is G1, and the gap G after occurrence of the touch force is G2, which is smaller than G1.

Such a decrease of the gap G from G1to G2, before and after occurrence of a force touch, changes the second capacitance C2and enables recognition of the force touch.

The gap structure unit1000ofFIG. 16has a small thickness and therefore can implement a touch display device100capable of force touch sensing without increasing the size thereof.

Referring toFIG. 17, the gap structure unit1000may include an inner pattern1700embedded in a lower structure1100and the like.

The inner pattern1700is a pattern provided inside the lower structure1100(for example, a backlight unit).

In this case, the inner pattern1700may be made of a conductive material or a nonconductive material.

The inner pattern1700is made of a material that has elasticity, and thus can be pressed by an external force (force touch) and then can be restored.

In addition, due to the elasticity, the inner pattern1700can prevent, even when pressed by an external force, the external force from being transferred to the second electrode E2. That is, the inner pattern1700prevent deformation of the second electrode E2.

When a force touch occurs, the upper cover1240, the display panel110, the lower structure1100, and the like receive a downward force.

Accordingly, the inner pattern1700, which is inside the lower structure1100, also receives the force, and the force may cause a change in size of the touch force sensing gap (G1→G2), which corresponds to the thickness of the inner pattern1700.

The gap G before occurrence of the force touch is G1, and the gap G after occurrence of the touch force is G2, which is smaller than G1.

Such a decrease of the gap G from G1to G2, before and after occurrence of a force touch, changes the second capacitance C2and enables recognition of the force touch.

The gap structure unit1000ofFIG. 17is included inside the lower structure1100and therefore can implement a touch display device100capable of force touch sensing without changing the size of the touch display device.

Referring toFIG. 18, the gap structure unit1000may be a guide panel positioned along the lower edge of the display panel110.

In this case, the lower structure1100may be positioned inside the gap structure unit1000, which may be a guide panel. In this regard, the lower structure1100may be a backlight unit for emitting light to the display panel110from the liquid crystal display device.

A second electrode E2may be positioned beneath the lower structure1100.

A touch force sensing gap G may be positioned between the upper portion of the lower structure1100and the display panel110.

Alternatively, an additional touch force sensing gap G may be positioned between the lower portion of the lower structure1100and the second electrode E2.

On the other hand, the gap structure unit1000, which supports the edge portion of the display panel, guarantees that, even if the screen portion is pressed by an external force (force touch), the upper surface of the lower structure1100does not make a direct contact with the rear surface of the display panel110(i.e., the rear surface of the first polarization plate1210).

Therefore, the force with which the user presses the screen portion is not directly transferred to the second electrode E2. As a result, the second electrode E2is not deformed.

When a force touch occurs on the screen portion, the upper cover1240, the display panel110, and the like receive a downward force.

This may cause a change in size of the gap G existing between the upper portion of the lower structure1100and the display panel110(G1→G2).

The gap G before occurrence of the force touch is G1, and the gap G after occurrence of the touch force is G2, which is smaller than G1.

Such a decrease of the gap G from G1to G2, before and after occurrence of a force touch, changes the second capacitance C2between the first electrode E1and the second electrode E2and enables recognition of the force touch.

On the other hand, the change in size of the touch force sensing gap G, when a touch force occurs, may differ depending on the position.

The change in size of the touch force sensing gap, which exists between the first electrode E1and the second electrode E2, at the center point of the screen is larger than the change in size of the touch force sensing gap, which exists between the first electrode E1and the second electrode E2, at the edge point of the screen.

This results from the structural characteristics for touch force sensing, and occurs because the gap structure unit1000supports the edge portion of the display panel110that lies on the upper portion of the gap structure unit1000.

Given that the change in size of the touch force sensing gap G differs depending on the position, the degree of change of the second capacitance C2, which is formed between each first electrode E1and the second electrode E2, varies depending on the position of each first electrode E1, and, as a result, the signal received at each first electrode E1may also vary.

This makes it possible not only to sense whether a touch force exists or not on the basis of the signal received at each first electrode E1, but also to sense the position in which the touch force has occurred by comparing the size relationship among the signals received at respective first electrodes E1.

FIG. 19is a diagram illustrating two driving types (driving type A and driving type B) related to a touch mode period TM, between two operation modes (display mode and touch mode) of a touch display device100according to the present embodiments.

Referring toFIG. 19, the touch display device100may operate in a “display mode” for displaying images or may operate in a “touch mode” for sensing at least one of a touch position and a touch force.

Referring toFIG. 19, the display mode period DM and the touch mode period TM may be time-divided and then proceed.

For example, the touch display device100may time-divide a single frame period into a display mode period DM and a touch mode period TM such that a display mode and a touch mode alternate within a single frame period. It is to be noted that, in some frame periods, display mode periods DM may solely exist.

As another example, the touch display device100may time-divide a single frame period into two or more display mode periods DM and two or more touch mode periods TM such that a display mode and a touch mode alternate within the single frame period.

As described above, the driving circuit120of the touch display device100can sense a touch position and a touch force during a touch mode period TM.

To this end, the driving circuit120may drive multiple first electrodes E1or may drive multiple first electrodes E1and at least one second electrode E2.

During a touch mode period TM, the driving circuit120may drive the multiple first electrodes E1and the at least one second electrode E2in one of two driving schemes.

Referring toFIG. 19, the two driving schemes include (1) a simultaneously driving scheme, in which driving for sensing a touch position and driving for sensing a touch force proceed simultaneously (Driving type A) and (2) a separate driving scheme, in which driving for sensing a touch position and driving for sensing a force touch proceed separately (Driving Type B).

In the case of the simultaneous driving scheme, during each touch mode period TM, at least one of the multiple first electrodes E1is driven successively, and the second electrode E2is driven simultaneously (i.e., driving for sensing a touch position and driving for sensing a touch force proceed simultaneously), and, according to the result of driving during one or at least two touch mode periods TM, the touch position and the touch force may be sensed simultaneously.

In the case of the separate driving scheme, a single touch mode period TM may include at least one of a touch driving period TD and a force driving period FD.

For example, each touch mode period TM may include at least one touch driving period TD and at least one force driving period FD.

In addition, each touch mode period TM may solely include at least one touch driving period TD or may solely include at least one force driving period FD.

Furthermore, the touch driving period TD and the force driving period FD are not supposed to be temporally adjacent directly to each other. That is, a display mode period DM may exist between the touch driving period TD and the force driving period FD.

Hereinafter, the simultaneous driving scheme, in which driving for sensing a touch position and driving for sensing a touch force proceed simultaneously (Driving Type A), will be described with reference toFIG. 20AtoFIG. 20CandFIG. 21AtoFIG. 21D.

FIG. 20AandFIG. 20Billustrate exemplary schemes of assigning display mode periods DM and touch mode periods TM with regard to the simultaneous driving scheme, in which driving for sensing a touch position and driving for sensing a touch force proceed simultaneously (Driving Type A), of a touch display device100according to the present embodiments.

Referring toFIG. 20A, in the case of the simultaneous driving scheme, in which driving for sensing a touch position and driving for sensing a touch force proceed simultaneously during a touch mode period TM (Driving Type A), a single frame period may be time-divided into a display mode period DM and a touch modem period TM.

All frame periods may be time-divided into display mode periods DM and touch mode periods TM; alternatively, only some of all frame periods may be time-divided into display mode periods DM and touch mode periods TM.

Referring toFIG. 20B, in the case of the simultaneous driving scheme, in which driving for sensing a touch position and driving for sensing a touch force proceed simultaneously during a touch mode period TM (Driving Type A), a single frame period may be time-divided into two or more display mode periods DM and two or more touch mode periods TM.

All frame periods may be time-divided into two or more display mode periods DM and two or more touch mode periods TM; alternatively, only some of all frame periods may be time-divided into two or more display mode periods DM and two or more touch mode periods TM.

Referring toFIG. 20AandFIG. 20B, in the case of a soft touch, which is generated by a pointer that has a contact portion made of a conductor, and which is generated by a pressing force equal to or less than a predetermined level (Case1ofFIG. 3), the driving circuit120may simultaneously conduct driving for sensing a touch position and driving for sensing a touch force and then may sense the touch position only, with regard to the touch, on the basis of signals received from respective first electrodes E1.

In addition, in the case of a force touch, which is generated by a pointer that has a contact portion made of a conductor, and which is generated by a pressing force exceeding the predetermined level (Case2ofFIG. 3), the driving circuit120may simultaneously sense the touch position and the touch force, with regard to the touch, on the basis of signals received from respective first electrodes E1.

In addition, in the case of a force touch, which is generated by a pointer that has a contact portion made of a nonconductor, and which is generated by a pressing force exceeding the predetermined level (Case3ofFIG. 3), the driving circuit120may sense the touch force only, with regard to the touch, on the basis of signals received from respective first electrodes E1.

As described above, driving for sensing a touch position and driving for sensing a touch force may proceed simultaneously such that the touch position and the touch force can be sensed simultaneously. This can reduce the time needed to sense the touch position and the touch force, and the display mode period DM, which is assigned for image display, can be lengthened in proportion thereto, thereby helping improve the image quality.

It is to be noted that, among the three touch schemes (Case1, Case2, and Case3), only the touch position can be sensed in the case of a soft touch (Case1), and only the touch force can be sensed in the case of a force touch by a nonconductor pointer (Case3).

However, the driving method does not differ with regard to each of the three touch schemes (Case1, Case2, and Case3). Only the kind of the obtained sensing result information (at least one of the touch position and the touch force) differs depending on the three touch schemes (Case1, Case2, and Case3).

On the other hand, during each touch mode period TM, the driving circuit120successively applies a first electrode driving signal DS1to at least one of the multiple first electrodes Dl and simultaneously applies a second electrode driving signal DS2to the second electrode E2, thereby simultaneously conducting driving for sensing a touch position and driving for sensing a touch force and detecting signals received from respective first electrodes E1.

After conducting all driving during one or at least two touch mode periods TM within one frame period, the driving circuit120may sense at least one of the touch position and the touch force, with regard to a single touch, on the basis of signals received from respective first electrodes E1, i.e. on the basis of sensing values related to detection signals from respective first electrodes E1.

According to the above description, it is unnecessary to separately conduct signal detection processing for sensing a touch position and signal detection processing for sensing a touch force, but it is possible to simultaneously sense the touch position and the touch force on the basis of a signal obtained by signal detection processing through one kind of electrode (i.e. each first electrode E1).

FIG. 20Cillustrates exemplary four combinations of a first electrode driving signal DS1, which is applied to a first electrode E1, and a second electrode driving signal DS2, which is applied to a second electrode E2, when a driving circuit120of a touch display device100according to the present embodiments simultaneously conducts driving for sensing a touch position and driving for sensing a touch force.

As in the case of Combination1to Combination4illustrated inFIG. 20C, the first electrode driving signal DS1may be a pulse-type signal, and the second electrode driving signal DS2may be a pulse-type signal or a single having a DC voltage.

AS described above, the fact that various combinations of the first electrode driving signal DS1and the second electrode driving signal DS2enable driving that conforms to the power supply system environment of the touch display device100or system environments thereof, such as signal generation, signal conversion scheme, or the like.

AS described above, the fact that driving can be conducted using a first electrode driving signal DS1and a second electrode driving signal DS2, which has an equiphase or reverse-phase relationship, during a touch mode period TM enables driving that conforms to the power supply system environment of the touch display device100or system environments thereof, such as signal generation, signal conversion scheme, or the like.

When the first electrode driving signal DS1and the second electrode driving signal DS2are pulse-type signals having an equiphase relationship, as in the case of Combination1ofFIG. 20C, the second electrode driving signal DS2have the same phase and the same frequency as those of the first electrode driving signal DS1. However, the amplitude V2of the second electrode driving signal DS2is larger than the amplitude V1of the first electrode driving signal DS1.

As described above, when the first electrode driving signal DS1and the second electrode driving signal DS2are pulse-type signals having an equiphase relationship, the amplitude V2of the second electrode driving signal DS2can be made larger than the amplitude V1of the first electrode driving signal DS1such that, even if touch position information and touch force information are mixed and exist in signals received through the first electrodes E1, the touch position and the touch force can be accurately distinguished and sensed.

On the other hand, when the first electrode driving signal DS1and the second electrode driving signal DS2are pulse-type signals having a reverse-phase relationship, the second electrode driving signal DS2has the same phase and the same frequency as those of the first electrode driving signal DS1. The amplitude V2of the second electrode driving signal DS2may be larger than, smaller than, or identical to the amplitude V1of the first electrode driving signal DS1.

On the other hand, when the second electrode driving signal DS2is a signal having a DC voltage, as in the case of Combinations3and4illustrated inFIG. 20C, the DC voltage may be a predetermined reference voltage Vref2or a ground voltage GND.

FIG. 21AtoFIG. 21Dare diagrams illustrating exemplary signal waveforms applied to a first electrode E1and a second electrode E2during a display mode period DM and a touch mode period TM, when a touch display device100according to the present embodiments simultaneously conducts driving for sensing a touch position and driving for sensing a touch force during a touch mode period TM.

Referring toFIG. 21AtoFIG. 21D, the display mode period DM and the touch mode period TM may be defined by a synchronization signal SYNC.

For example, when the synchronization signal SYNC is at a high level (or low level), the operation mode period of the touch display device100may correspond to the display mode period DM; and, when the synchronization signal SYNC is at a low level (or high level), the operation mode period of the touch display device100may correspond to the touch mode period TM.

The synchronization signal SYNC may be a control signal provided from a timing controller (not illustrated) to the driving circuit120.

FIG. 21Acorresponds to a case in which Combination1ofFIG. 20Cis used for driving during the touch mode period TM;FIG. 21Bcorresponds to a case in which Combination2ofFIG. 20Cis used for driving during the touch mode period TM;FIG. 21Ccorresponds to a case in which Combination3ofFIG. 20Cis used for driving during the touch mode period TM; andFIG. 21Dcorresponds to a case in which Combination4ofFIG. 20Cis used for driving during the touch mode period TM.

Referring toFIG. 21A,FIG. 21B,FIG. 21C, andFIG. 21D, a display driving voltage DDV may be applied to multiple first electrodes E1during the display mode period DM.

For example, a common voltage Vcom, which corresponds to the display driving voltage DDV, may be applied to all of the multiple first electrodes E1.

Although the low level voltage of the first electrode driving signal DS1is illustrated as being equal to the display driving voltage DDV inFIG. 21A,FIG. 21B,FIG. 21C, andFIG. 21D, the low level voltage of the first electrode driving signal DS1may be lower or higher than the display driving voltage DDV in some cases.

In addition, although application of the ground voltage GND to the second electrode E2during the display mode terminal DM is illustrated inFIG. 21A,FIG. 21B,FIG. 21C, andFIG. 21D, the same is only an example; not only the ground voltage GND, but also the display driving voltage DDV may be applied; a different specific DC voltage may be applied; an AC voltage (pulse signal) may be applied; or no voltage may be applied (floating state).

Hereinafter, the separate driving scheme, in which driving for sensing a touch position and driving for sensing a touch force proceed separately (Driving Type B), will be described with reference toFIG. 22AtoFIG. 22EandFIG. 23AtoFIG. 23E.

FIG. 22AandFIG. 22Cillustrate exemplary schemes of assigning display mode periods DM and touch mode periods TM with regard to the separate driving scheme, in which driving for sensing a touch position and driving for sensing a touch force proceed separately (Driving Type B), during the touch mode period TM of a touch display device100according to the present embodiments.

Referring toFIG. 22AandFIG. 22B, in the case of the separate driving scheme, in which driving for sensing a touch position and driving for sensing a touch force proceed separately during a touch mode period TM (Driving Type B), each touch mode period TM may include a touch driving period TD for sensing a touch position and a force driving period FD for sensing a touch force.

For example, as illustrated inFIG. 22AandFIG. 22B, each of all touch mode periods TM may include a touch driving period TD for sensing a touch position and a force driving period FD for sensing a touch force.

As another example, as illustrated inFIG. 22C, one or more touch mode periods TM may solely include a touch driving period TD for sensing a touch position, and one or more different touch mode periods TM may include both a touch driving period TD for sensing a touch position and a force driving period FD for sensing a touch force.

As another example, one or more touch mode periods TM may solely include a touch driving period TD, and one or more different touch mode periods DM may solely include a force driving period FD.

Besides above examples, any type of period assignment is possible as long as the touch driving period TD and the force driving period FD are separated from each other.

On the other hand, referring toFIG. 22AtoFIG. 22C, a single frame period always includes at least one display mode period DM.

In addition, as illustrated inFIG. 22AtoFIG. 22C, a single frame period may or may not always include at least one touch mode period TM.

That is, one or at least two touch mode periods TM may exist during each of at least one frame period.

One or more touch driving periods TD may exist in each frame period.

Alternatively, one or more touch driving periods TD may exist in each of two or more frame periods. That is, no touch driving period TD may exist in some frame periods.

In addition, one or more force driving periods FD may exist in each frame period.

Alternatively, one or more force driving periods FD may exist in each of two or more frame periods. That is, no force driving period FD may exist in some frame periods.

Referring toFIG. 22AtoFIG. 22C, the driving circuit120successively applies a first electrode driving signal DS1, which correspond to a touch driving signal TDS, to at least one of multiple first electrodes E1, during a touch driving period TD, and senses a touch position, with regard to the touch, on the basis of signals received from respective first electrodes E1.

The driving circuit120may apply a first electrode driving signal DS1, which corresponds to a first force driving signal FDS1, to all or some of the multiple first electrodes E1, during a force driving period FD, may simultaneously apply a second electrode driving signal DS2, which corresponds to a second force driving signal FDS2, to the second electrode E2, and may sense a touch force, with regard to the touch, on the basis of signals received from respective first electrodes E1.

As described above, driving for sensing a touch position and driving for sensing a touch force proceed separately such that the touch position and the touch force can be sensed accurately and without confusion.

FIG. 22DandFIG. 22Eillustrate exemplary eight combinations of a first force driving signal FDS1, which is applied to a first electrode E1, and a second force driving signal FDS2, which is applied to a second electrode E2, when a driving circuit120of a touch display device100according to the present embodiments separately conducts driving for sensing a touch position and driving for sensing a touch force.

As in the case of Combinations1and2illustrated inFIG. 22D, the first force driving signal FDS1and the second force driving signal FDS2both may be pulse-type signals.

Alternatively, as in the case of Combinations3and4illustrated inFIG. 22D, the first force driving signal FDS1may be a pulse-type signal, and the second force driving signal FDS2may be a signal having a second DC voltage.

Alternatively, as in the case of Combinations5and6illustrated inFIG. 22D, the first force driving signal FDS1may be a signal having a first DC voltage, and the second force driving signal FDS2may be a pulse-type signal.

Alternatively, as in the case of Combinations7and8illustrated inFIG. 22E, the first force driving signal FDS1may be a signal having a first DC voltage, and the second force driving signal FDS2may be a signal having a second DC voltage.

As described above, it is possible to selectively use one or at least two of various combinations of the first force driving signal FDS1and the second force driving signal FDS2according to the system environment, thereby providing efficient driving for sensing a touch force.

When the first force driving signal FDS1and the second force driving signal FDS2are pulse-type signals as in the case of Combinations1and2illustrated inFIG. 22D, the first force driving signal FDS1and the second force driving signal FDS2may have an equiphase relationship or a reverse-phase relationship.

As described above, the phase relationship (equiphase relationship or reverse-phase relationship) between the first force driving signal FDS1and the second force driving signal FDS2can be properly selected and used in view of the signal generating configuration and the force driving and sensing configuration, thereby improving the efficiency of the signal generating configuration and of the force driving and sensing configuration.

When the first force driving signal FDS1and the second force driving signal FDS2are pulse-type signals having an equiphase relationship as illustrated in Combination1ofFIG. 22D, the second force driving signal FDS2has the same phase and the same frequency as those of the first force driving signal FDS1. However, the amplitude V2of the second force driving signal FDS2is larger than the amplitude V1of the first force driving signal FDS1.

When the first force driving signal FDS1and the second force driving signal FDS2are pulse-type signals having an equiphase relationship as described above, the amplitude V2of the second force driving signal FS2can be made larger than the amplitude V1of the first force driving signal FDS1such that, when a force is sensed on the basis of a received signal received through a first electrode E1, it can be accurately distinguished whether the corresponding touch is a force touch or a soft touch, thereby accurately sensing whether a touch force exists or not and the magnitude thereof.

When the first force driving signal FDS1and the second force driving signal FDS2have a reverse-phase relationship, the second force driving signal FDS2has the same phase and the same frequency as those of the first force driving signal FDS1. The amplitude V2of the second force driving signal FDS2may be identical to or different from the amplitude V1of the first force driving signal FDS1.

The first DC voltage of the first force driving signal FDS1may be a first reference voltage Vref1or a ground voltage GND.

The second DC voltage of the second force driving signal FDS2may be a second reference voltage Vref2or a ground voltage GND.

The first reference voltage Vref1and the second Vref2may be identical or different.

When the first force driving signal FDS1is a signal having a first DC voltage, and when the second force driving signal FDS2is a signal having a second DC voltage, the first DC voltage and the second DC voltage may differ from each other.

FIG. 23AtoFIG. 23Eare diagrams illustrating exemplary signal waveforms applied to a first electrode E1and a second electrode E2during a display mode period DM, a touch mode period TM, and a force driving period FD, when a touch display device100according to the present embodiments separately conducts driving for sensing a touch position and driving for sensing a touch force during a touch mode period TM.

FIG. 23Acorresponds to a case in which Combination1ofFIG. 22Cis used for driving during the touch mode period TM;FIG. 23Bcorresponds to a case in which Combination2ofFIG. 22Cis used for driving during the touch mode period TM;FIG. 23Ccorresponds to a case in which Combination3ofFIG. 22Cis used for driving during the touch mode period TM;FIG. 23Dcorresponds to a case in which Combination4ofFIG. 22Cis used for driving during the touch mode period TM; andFIG. 23Ecorresponds to a case in which Combination6ofFIG. 22Cis used for driving during the touch mode period TM.

Referring toFIG. 23AtoFIG. 23E, a display driving voltage DDV may be applied to multiple first electrodes E1during the display mode period DM.

For example, a common voltage Vcom, which corresponds to the display driving voltage DDV, may be applied to all of the multiple first electrodes E1.

Although application of the ground voltage GND to the second electrode E2during the display mode period DM is illustrated, this is only an example; not only the ground voltage GND, but also the display driving voltage DDV may be applied; a different specific DC voltage may be applied; an AC voltage (pulse signal) may be applied; or no voltage may be applied (floating state).

Referring toFIG. 23AtoFIG. 23E, during a touch driving period TD included in the touch mode period TM, a touch driving signal TDS, which corresponds to a first electrode driving signal DS1, may be applied to the multiple first electrodes E1. In this regard, the touch driving signal TDS may be a signal such as the pulse-type first electrode driving signal DS1illustrated inFIG. 5.

Although application of the ground voltage GND to the second electrode E2during the touch driving period TD included in the touch mode period TM is illustrated, this is only an example; not only the ground voltage GND, but also the display driving voltage DDV may be applied; a different specific DC voltage may be applied; an AC voltage (pulse signal) may be applied; or no voltage may be applied (floating state).

On the other hand, when a touch driving signal TDS is being applied to a first electrode E1during a touch driving period TD, a parasitic capacitance may be formed between the first electrode E1and the second electrode E2.

Such a parasitic capacitance may act as sensing noise when a touch position is sensed on the basis of a signal received through the first electrode E1.

Therefore, during a touch driving period TD, a second electrode driving signal DS2, which has at least one of the same frequency, the same phase, and the same amplitude as that of the touch driving signal TDS that is applied to the first electrode E1, may be applied to the second electrode E2.

This can prevent formation of a parasitic capacitance between the first electrode E1and the second electrode E2, thereby improving the sensing accuracy.

In this regard, the second electrode driving signal DS2, which has at least one of the same frequency, the same phase, and the same amplitude as that of the touch driving signal TDS that is applied to the first electrode E1during the touch driving period TD, is referred to as a load-free driving signal.

Although the low level voltages of the touch driving signal TDS and the first force driving signal FDS1, which correspond to the first electrode driving signal DS1, are illustrated as being equal to the display driving voltage DDV inFIG. 23AtoFIG. 23E, the low level voltages may be lower or higher than the display driving voltages DDV in some cases.

In addition, although application of the ground voltage GND to the second electrode E2during the display mode period DM and the touch driving period TD is illustrated inFIG. 23AtoFIG. 23E, this is only an example; not only the ground voltage GND, but also the display driving voltage DDV may be applied; a different specific DC voltage may be applied; an AC voltage (pulse signal) may be applied; or no voltage may be applied (floating state).

During a force driving period TD included in the touch mode period TM, a first force driving signal FDS1, which corresponds to a first electrode driving signal DS1of a pulse type, may be applied to the first electrode E1, as illustrated inFIG. 23AtoFIG. 23D, or a first force driving signal FDS1, which corresponds to a first electrode driving signal DS1of a first DC voltage (for example, Vref1, GNC, Vcom, or the like), may be applied to the first electrode E1as illustrated inFIG. 23E.

FIG. 24is a flowchart of a simultaneous driving method for simultaneously conducting driving for sensing a touch position and driving for sensing a touch force during a touch mode period TM by a touch display device100according to the present embodiments.

Referring toFIG. 24, the simultaneous driving method by a touch display device100according to the present embodiments, when the touch display device100simultaneously conducts driving for sensing a touch position and driving for sensing a touch force during a touch mode period TM, comprises the steps of: driving multiple data lines and multiple gate lines, which are arranged on a display panel110, during a display mode period DM such that the gradation of each subpixel is adjusted, thereby driving the display panel110(S2410); successively applying a first electrode driving signal DS1to at least one of multiple first electrodes E1, which are embedded in the display panel110, and simultaneously applying a second electrode driving signal DS2to a second electrode E2, which is positioned outside the display panel110, such that the touch position and the touch force are simultaneously sensed with regard to a single touch (S2420); and the like.

The above-mentioned simultaneous driving method, when employed, makes it possible to simultaneously sense the touch position and the touch force, with regard to a touch generated by a pointer such as a finger, a pin, or the like, through the same driving scheme during the touch mode period TM.

FIG. 25AandFIG. 25Bare diagrams illustrating a driving circuit120for simultaneous driving by a touch display device100according to the present embodiments.

Referring toFIG. 25AandFIG. 25B, assuming that the touch display device100according to the present embodiments simultaneously conducts driving for sensing a touch position and driving for sensing a touch force during a touch mode period TM, the driving circuit120of the touch display device100may include a signal generating circuit2500, a first electrode driving circuit2510, a second electrode driving circuit2520, and the like.

Referring toFIG. 25AandFIG. 25B, the signal generating circuit2500may generate and output a first electrode driving signal DS1.

The signal generating circuit2500may further generate a second electrode driving signal DS2.FIG. 25Ais a diagram illustrating the driving circuit120when the signal generating circuit2500generates the second electrode driving signal DS2, andFIG. 25Bis a diagram illustrating the driving circuit120when the signal generating circuit2500does not generate the second electrode driving signal DS2.

Referring toFIG. 25AandFIG. 25B, the first electrode driving circuit2510may apply a display driving voltage to multiple first electrodes E1, which are embedded in the display panel110, during a display mode period DM and may successively apply a first electrode driving signal DS1to at least one of the multiple first electrodes E1, which are embedded in the display panel110, during a touch mode period TM.

The first electrode driving circuit2510may include the integrator730, the analog-digital converter ADC, and the like, which are illustrated inFIG. 7.

Assuming that the multiple first electrodes E1are one of display driving electrodes, to which a display driving voltage DDV is applied during a display mode period DM, the first electrode driving circuit2510may apply the display driving voltage to all of the multiple first electrodes E1during the display mode period DM.

Therefore, the multiple first electrodes E1play the role of display driving electrodes in a display mode period DM and play the role of a touch sensor and a force sensor in a touch mode period TM.

Referring toFIG. 25AandFIG. 25B, the second electrode driving signal2520is a circuit for applying a second electrode driving signal DS2to a second electrode E2, which is positioned outside the display panel110, in a touch mode period TM. For example, the second electrode driving circuit2520may be implemented as at least one printed circuit, on which signal wiring is arranged so as to transfer a second electrode driving signal DS2to the second electrode E2.

Using the above-mentioned driving circuit120makes it possible to provide a touch sensing function of sensing a touch position and a force sensing function of sensing a touch force. Particularly, driving for sensing a touch position and driving for sensing a touch force can proceed simultaneously, thereby providing two kinds of touch-related driving and sensing efficiently.

Referring toFIG. 25A, the signal generating circuit2500may further generate and output a second electrode driving signal DS2.

Accordingly, the second electrode driving circuit2520may transfer the second electrode driving signal DS2, which has been generated and output by the signal generating circuit2500, to the second electrode E2.

Given that the signal generating circuit2500additionally generates and outputs a second electrode driving signal DS2, besides the first electrode driving signal DS1, as illustrated inFIG. 25A, driving in the touch mode period may be facilitated by using the second electrode driving signal DS2, which has a type different from that of the first electrode driving signal DS1.

Referring toFIG. 25B, the signal generating circuit2500does not generate the second electrode driving signal DS2; therefore, the driving circuit120may further include a signal converter2540configured to convert the first electrode driving signal DS1, which has been generated by the signal generating circuit2500, thereby generating a second electrode driving signal DS2.

The signal converter2540may convert at least one of the amplitude, phase, and the like of the first electrode driving signal DS1, for example, thereby generating a second electrode driving signal DS2.

In this case, the signal generating circuit2500has only to generate the first electrode driving signal DS1; as a result, the signal generating burden can be alleviated, and efficient touch driving can be provided.

The signal converter2540may include, for example, a level shifter configured to adjust the signal voltage level, may include a phase controller configured to control the signal phase, and may include a DA converter configured to convert a DC signal to an AC signal (pulse signal) or an AD converter configured to convert an AC signal (pulse signal) to a DC signal. The signal converter2540may be regarded as a second electrode driving circuit2520, and may also be regarded as being included in the second electrode driving circuit2520.

Referring toFIG. 25AandFIG. 25B, the driving circuit120may further include a sensing processor2530configured to sense at least one of the touch position and the touch force, with regard to a single touch, on the basis of a signal received from at least one first electrode E1through the first electrode driving circuit120in a touch mode period TM.

The sensing processor2530may have a configuration corresponding to that of the processor740illustrated inFIG. 7.

As described above, the sensing processor2530receives the signal, which has been received from the first electrode E1, through the first electrode driving circuit2510and senses not only the touch position, but also the touch force, thereby being able to efficiently performing two kinds of sensing in the same processing scheme.

On the other hand, each of the signal generating circuit2500, the first electrode driving circuit2510, and the sensing processor2530may be implemented as a separate integrated circuit or a processor.

For example, the signal generating circuit2500may be implemented as a power IC, and the sensing processor2530may be a MCU (Micro Controller Unit). The first electrode driving circuit2510may be implemented as a first electrode driving IC.

On the other hand, at least two of the signal generating circuit2500, the first electrode driving circuit2510, and the sensing processor2530may be implemented as a single IC.

For example, the signal generating circuit2500and the first electrode driving circuit2510may be included in a single IC and implemented as such.

As another example, the signal generating circuit2500, the first electrode driving circuit2510, and the sensing processor2530may be integrally included in a single IC and implemented as such.

On the other hand, the first electrode driving circuit2510may further include a data driving circuit configured to apply a data voltage to multiple data lines, which are arranged on the display panel110, during a display mode period.

As described above, the fact that the driving circuit120can be implemented in various types makes it possible to design a driving circuit120, which is optimized to the size of the touch display device100(for example, medium/large TV size, mobile terminal size, or the like), the system environment, or the power supply system environment.

FIG. 26is a flowchart of a separate driving method by which a touch display device100according to the present embodiments separately conducts driving for sensing a touch position and driving for sensing a touch force during a touch mode period TM.

Referring toFIG. 26, the separate driving method by a touch display device100according to the present embodiments, when the touch display device100separately conducts driving for sensing a touch position and driving for sensing a touch force during a touch mode period TM, includes the steps of: driving a display panel110in a display mode period DM (S2610); successively applying a touch driving signal TDS to at least one of multiple first electrodes E1, which are embedded in the display panel110, in a touch driving period TD, thereby sensing the touch position with regard to the touch (S2620); applying a first force driving signal FDS1to all or some of the multiple first electrodes E1, during a force driving period FD within a touch mode period TM, and simultaneously applying a second force driving signal FDS2to a second electrode E2, thereby sensing the touch force with regard to the touch (S2630); and the like.

The above-mentioned separate driving method, when employed, makes it possible to separately sense the touch position and the touch force, with regard to a touch generated by a pointer such as a finger, a pin, or the like, through different driving schemes, respectively, thereby accurately sensing the touch position and the touch force.

FIG. 27AandFIG. 27Bare diagrams illustrating a driving circuit120for separate driving by a touch display device100according to the present embodiments.

Referring toFIG. 27AandFIG. 27B, assuming that the touch display device100according to the present embodiments separately conducts driving for sensing a touch position and driving for sensing a touch force during a touch mode period TM, the driving circuit120of the touch display device100may include a signal generating circuit2700, a first electrode driving circuit2710, a second electrode driving circuit2720, and the like.

The signal generating circuit2700may generate and output a touch driving signal TDS and a first force driving signal FDS1.

In this regard, the touch driving signal TDS corresponds to a first electrode driving signal DS1, which is generated and output during a touch driving period TD, and the first force driving signal FDS1corresponds to a first electrode driving signal DS1, which is generated and output during a force driving period FD.

The signal generating circuit2700may additionally generate a second force driving signal FDS2, which corresponds to a second electrode driving signal DS2.FIG. 27Ais a diagram illustrating a driving circuit120when the signal generating circuit2700generates a second force driving signal FDS2, andFIG. 27Bis a diagram illustrating the driving circuit120when the signal generating circuit2700does not generate the second force driving signal FDS2.

Referring toFIG. 27AandFIG. 27B, the first electrode driving circuit2710applies a display driving voltage DDV (for example, Vcom) to multiple first electrodes E1, which are embedded in the display panel110, during a display mode period DM, successively applies a touch driving signal TDS, which corresponds to a first electrode driving signal DS1, to at least one of the multiple first electrodes E1during a touch mode period TM, receives an input of a first force driving signal FDS1during a force driving period FD within the touch mode period TM, and applies a first force driving signal FDS1, which corresponds to the first electrode driving signal DS1, to all or some of the multiple first electrodes E1.

The first electrode driving circuit2710may include the integrator730, the analog-digital converter ADC, and the like, illustrated inFIG. 7.

Assuming that the multiple first electrodes E1are one of display driving electrodes, to which a display driving voltage DDV is applied during a display mode period DM, the first electrode driving circuit2710may apply the display driving voltage to all of the multiple first electrodes E1during the display mode period DM.

Therefore, the multiple first electrodes E1play the role of display driving electrodes in a display mode period DM, play the role of a touch sensor in a touch mode period TM, and play the role of a force sensor in a force driving period FD.

Referring toFIG. 27AandFIG. 27B, the second electrode driving circuit2720is a circuit for applying a second force driving signal FDS2, which corresponds to a second electrode driving signal DS2, to a second electrode E2, which is positioned outside the display panel110, in a touch mode period TM. For example, the second electrode driving circuit2720may be implemented as at least one printed circuit, on which signal wiring is arranged so as to transfer a second force driving signal FDS2, which corresponds to a second electrode driving signal DS2, to the second electrode E2.

Using the above-mentioned driving circuit120makes it possible to provide a touch sensing function of sensing a touch position and a force sensing function of sensing a touch force. Particularly, driving for sensing a touch position and driving for sensing a touch force can proceed separately, thereby providing two kinds of touch-related driving and sensing independently and accurately.

Referring toFIG. 27A, the signal generating circuit2700may further generate and output a second force driving signal FDS2, which corresponds to a second electrode driving signal DS2.

Accordingly, the second electrode driving circuit2720may transfer the second force driving signal FDS2, which corresponds to the second electrode driving signal DS2that has been generated and output by the signal generating circuit2700, to the second electrode E2.

Given that the signal generating circuit2500additionally generates and outputs a second force driving signal FDS2, which corresponds to a second electrode driving signal DS2, besides the touch driving signal TDS and the first force driving signal FDS1, which are first electrode driving signals DS1, as illustrated inFIG. 27A, force driving in the force driving period FD may be facilitated by using the second force driving signal FDS2, which has a type different from that of the first force driving signal FDS1.

Referring toFIG. 27B, the signal generating circuit2700does not generate the second force driving signal FDS2, which corresponds to the second electrode driving signal DS2; therefore, the driving circuit120may further comprise a signal converter2740configured to convert the first force driving signal FDS1, which corresponds to the first electrode driving signal DS1that has been generated by the signal generating circuit2700, thereby generating a second force driving signal FDS2that corresponds to a second electrode driving signal DS2.

The signal converter2740may convert at least one of the amplitude, phase, and the like of the first force driving signal FDS1, for example, thereby generating a second force driving signal FDS2.

In this case, the signal generating circuit2700has only to generate the first force driving signal FDS1, which corresponds to the first electrode driving signal DS1; as a result, the signal generating burden can be alleviated, and efficient touch driving can be provided.

The signal converter2740may include, for example, a level shifter configured to adjust the signal voltage level, may include a phase controller configured to control the signal phase, and may include a DA converter configured to convert a DC signal to an AC signal (pulse signal) or an AD converter configured to convert an AC signal (pulse signal) to a DC signal. The signal converter2740may be regarded as a second electrode driving circuit2720, and may also be regarded as being included in the second electrode driving circuit2720.

Referring toFIG. 27AandFIG. 27B, the driving circuit120may further include a sensing processor2730configured to sense the touch position on basis of a signal received from each first electrode E1through the first electrode driving circuit2510in a touch driving period TD and configured to sense the touch force on basis of a signal received from each first electrode E1through the first electrode driving circuit2510in a force driving period FD.

The sensing processor2730may have a configuration corresponding to that of the processor740illustrated inFIG. 7.

As described above, the sensing processor2730receives a signal, which has been received from the first electrode E1, through the first electrode driving circuit2510during a touch driving period TD, thereby sensing the touch position, and receives a signal, which has been received from the first electrode E1, through the first electrode driving circuit2510during a force driving period FD, thereby sensing the touch force; as such, two kinds of sensing can be performed accurately.

On the other hand, each of the signal generating circuit2700, the first electrode driving circuit2710, and the sensing processor2730may be implemented as a separate integrated circuit or a processor.

For example, the signal generating circuit2700may be implemented as a power IC, and the sensing processor2730may be a MCU (Micro Controller Unit). The first electrode driving circuit2710may be implemented as a first electrode driving IC.

On the other hand, at least two of the signal generating circuit2700, the first electrode driving circuit2710, and the sensing processor2730may be implemented as a single IC.

For example, the signal generating circuit2700and the first electrode driving circuit2710may be included in a single IC and implemented as such.

As another example, the signal generating circuit2700, the first electrode driving circuit2710, and the sensing processor2730may be integrally included in a single IC and implemented as such.

On the other hand, the first electrode driving circuit2710may further include a data driving circuit configured to apply a data voltage to multiple data lines, which are arranged on the display panel110, during a display mode period.

As described above, the fact that the driving circuit120can be implemented in various types makes it possible to design a driving circuit120, which is optimized to the size of the touch display device100(for example, medium/large TV size, mobile terminal size, or the like), the system environment, or the power supply system environment.

FIG. 28andFIG. 29illustrate exemplary arrangements of first electrodes E1and second electrodes E2in connection with a touch display device100according to the present embodiments.

FIG. 28andFIG. 29illustrate examples in which sixty-four first electrodes E1are embedded and arranged in the display panel110.

Referring toFIG. 28, when the second electrode E2is a single bulk electrode, the second electrode E2may be positioned to face the sixty-four first electrodes E1.

Referring toFIG. 29, two or more second electrodes E2may exist.

For example, assuming for example that four second electrodes E2a, E2b, E2c, and E2dexist, each of the four second electrodes E2a, E2b, E2c, and E2dmay be positioned to face sixteen first electrodes among the sixty-four first electrodes E1.

In this regard, the number of second electrodes may be identical to the number of first electrodes, or may be larger or smaller than the number of first electrodes.

The number of second electrodes may be determined in view of the driving efficiency for sensing a touch force, the sensing accuracy, and the like.

Referring toFIG. 29, the second electrode E2amay be positioned to face a group of sixteen first electrodes (Group A), which have corresponding positions among the first electrodes E1. The second electrode E2bmay be positioned to face a group of sixteen first electrodes (Group B), which have corresponding positions among the first electrodes E1. The second electrode E2cmay be positioned to face a group of sixteen first electrodes (Group C), which have corresponding positions among the first electrodes E1. The second electrode E2dmay be positioned to face a group of sixteen first electrodes (Group D), which have corresponding positions among the first electrodes E1.

When two or more second electrodes E2exist as in the case ofFIG. 29, touch force sensing can be conducted with regard to each second electrode E2.

When the second electrode E2is a single bulk electrode, as in the case ofFIG. 28, it can be advantageously applied to a small display device, such as a mobile display device.

The structure of having two or more second electrodes E2, as in the case ofFIG. 29, can be applied to a large-area display device, a public display device, and the like, and can be combined with various applied technologies.

As described above, the present embodiments may provide a touch display device100, a method for driving the same, and a driving circuit120, the touch display device100being structured such that it cannot only sense the coordinate (position) of a touch generated by the user, but also sense the touch force, with which the user presses the screen during the touch, in order to provide various functions in various types.

The present embodiments may provide a driving circuit120, a touch display device100, and a method for driving the same, which enable simultaneous proceeding of driving for sensing a touch position and driving for sensing a touch force during a touch mode period.

The present embodiments may provide a driving circuit120, a touch display device100, and a method for driving the same, which enable separate proceedings of driving for sensing a touch position and driving for sensing a touch force during a touch mode period.

The present embodiments may provide a driving circuit120, a touch display device100, and a method for driving the same, which can recognize the position of occurrence of a touch force, i.e. a force with which the user's touch presses the screen.

The present embodiments may provide a driving circuit120, a touch display device100, and a method for driving the same, which can accurately distinguish between a soft touch, i.e. the force with which the user's touch presses the screen does not exist or is equal to or less than a predetermined level, and a force touch, i.e. the force with which the user's touch presses the screen exists or exceeds the predetermined level.

The present embodiments may provide a touch display device100including a display panel110, on which multiple first electrodes E1are arranged, at least one second electrode E2positioned outside the display panel120, and at least one touch force sensing gap G, which exists between the multiple first electrodes E1and the at least one second electrode E2, and which can change its size according to a touch force such that touch force sensing is possible.

The above description and the accompanying drawings provide an example of the technical idea of the present invention for illustrative purposes only. Those having ordinary knowledge in the technical field, to which the present invention pertains, will appreciate that various modifications and changes in form, such as combination, separation, substitution, and change of a configuration, are possible without departing from the essential features of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate the scope of the technical idea of the present invention, and the scope of the present invention is not limited by the embodiment. The scope of the present invention shall be construed on the basis of the accompanying claims in such a manner that all of the technical ideas included within the scope equivalent to the claims belong to the present invention.

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