Touch circuit, touch panel and display apparatus

The present disclosure relates to a touch circuit, a touch panel and a display apparatus.

With the rapid development of the display technique, a touch panel has become popular in the people's life gradually. At present, the touch panel can be divided, according to the composition and structure, into: an Add on Mode Touch Panel, an On Cell Touch Panel, and an In Cell Touch Panel. Herein, the Add on Mode Touch Panel means to manufacture the touch panel and the display screen separately, and then paste them together to form a display screen that has the touch function. The Add on Mode Touch Panel has deficiencies of relatively high manufacturing cost, relatively low light transmission rate, and relatively thick modules and so on. However, the In Cell Touch Panel embeds touch electrodes of the touch panel inside the display screen, which can reduce the thickness of the module as a whole, and can also reduce the manufacturing cost of the touch panel greatly, and thus it is preferred by a variety of panel manufacturers. In the In Cell Touch Panel technique, a mutual capacitive touch panel becomes a mainstream of the In Cell Touch Panel technique development at present due to its advantageous of relatively high flexibility and multi-point touch.

Specifically, the in cell touch panel is an apparatus whose touch scan lines and touch sense lines in the touch panel are integrated in the display screen, for example, the touch scan lines and the touch sense lines being integrated in a liquid crystal display (LCD) or an organic light emitting device (OLED).

At present, a touch driving circuit used to output touch scan signals to the touch scan lines is always integrated on an array substrate, so as to save wirings in a display frame area, so that a narrow frame design of a large-size display screen can be realized.

There are provided in embodiments of the present disclosure a touch circuit, a touch panel and a display apparatus, which are used to solve problems of relatively complicated touch circuit structure and relatively large power consumption existing in the prior art.

There is provided in an embodiment of the present disclosure a touch circuit, comprising: an input module, a reset module, a pull-up module, a pull-down module, a pull-down control module and a touch signal output module, wherein:

the input module has a control terminal connected to an input signal terminal, an input terminal connected to a first reference signal terminal, and an output terminal connected to a first node, and is configured to provide a signal of the first reference signal terminal to the first node under the control of the input signal terminal;

the reset module has a control terminal connected to a reset signal terminal, an input terminal connected to a second reference signal terminal, and an output terminal connected to the first node, and is configured to provide a signal of the second reference signal terminal to the first node under the control of the reset signal terminal;

the pull-up module has a control terminal connected to the first node, an input terminal connected to a first clock signal terminal, and an output terminal connected to a control signal output terminal, and is configured to provide a signal of the first clock signal terminal to the control signal output terminal when a potential of the first node is a first potential;

the pull-down module has a control terminal connected to a second node, an input terminal connected to a third reference signal terminal, and output terminal connected to the control signal output terminal, and is configured to provide a signal of the third reference signal terminal to the control signal output terminal when a potential of the second node is the first potential;

the pull-down control module is connected to a second clock signal terminal, the first node and the second node respectively, and is configured to provide a signal of the second clock signal terminal to the second node under the control of the second clock signal terminal, control the potential of the second node as a second potential when the potential of the first node is the first potential, and control the potential of the first node as the second potential when the potential of the second node is the first potential;

the touch signal output module has a first input terminal connected to the control signal output terminal, a second input terminal connected to a high frequency signal terminal, and a third input terminal connected to a common voltage signal terminal, and is configured to output a high frequency signal or a common voltage signal to a touch signal output terminal under the control of the control signal output terminal; and

when an active pulse signal of the input signal terminal is a high potential signal, the first potential is a high potential, and the second potential is a low potential; when an active pulse signal of the input signal terminal is a low potential signal, the first potential is a low potential, and the second potential is a high potential; and when the input signal terminal starts to output the active pulse signal, the first clock signal terminal and the second clock signal terminal output a first potential signal alternatively.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the pull-down control module comprises: a first pull-down control unit, a second pull-down control unit and a third pull-down control unit; wherein

the first pull-down control unit has a control terminal and an input terminal both connected to the second clock signal terminal, and an output terminal connected to the second node, and is configured to provide the signal of the second clock signal terminal to the second node under the control of the second clock signal terminal;

the second pull-down control unit has a control terminal connected to the first node, an input terminal connected to the third reference signal terminal, and an output terminal connected to the second node, and is configured to provide the signal of the third reference signal terminal to the second node when the potential of the first node is the first potential; and

the third pull-down control unit has a control terminal connected to the second node, an input terminal connected to the third reference signal terminal, and an output terminal connected to the first node, and is configured to provide the signal of the third reference signal terminal to the first node when the potential of the second node is the first potential.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the pull-down control module further comprises: a fourth pull-down control unit; wherein

the fourth pull-down control unit has a control terminal connected to the control signal output terminal, an input terminal connected to the third reference signal terminal, and an output terminal connected to the second node, and is configured to provide the signal of the third reference signal terminal to the second node when the potential of the control signal output terminal is the first potential.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the first pull-down control unit comprises a first switch transistor; wherein

the first switch transistor has both a gate and a source connected to the second clock signal terminal, and a drain connected to the first node.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the second pull-down control unit comprises: a second switch transistor; wherein

the second switch transistor has a gate connected to the first node, a source connected to the third reference signal terminal, and a drain connected to the second node.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the third pull-down control unit comprises: a third switch transistor; wherein

the third switch transistor has a gate connected to the second node, a source connected to the third reference signal terminal, and a drain connected to the first node.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the fourth pull-down control unit comprises: a fourth switch transistor; wherein

the fourth switch transistor has a gate connected to the control signal output terminal, a source connected to the third reference signal terminal, and a drain connected to the second node.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the touch signal output module comprises: a high frequency signal output unit, a common voltage signal output unit, a pull-up unit and a pull-down unit; wherein

the pull-up unit has a control terminal which is a first input terminal of the touch signal output module, an input terminal connected to a low frequency signal terminal, and an output terminal connected to the third node, and is configured to provide a signal of the low frequency signal terminal to the third node when the potential of the control signal output terminal is the first potential;

the pull-down unit has a control terminal connected to an end signal terminal, an input terminal connected to the third node, and an output terminal connected to the third reference signal terminal, and is configured to provide the signal of the third reference signal terminal to the third node under the control of the end signal terminal;

the high frequency signal output unit has a control terminal connected to the third node, an input terminal which is a second input terminal of the touch signal output module, and an output terminal connected to the touch signal output terminal, and is configured to control the touch signal output terminal to output the high frequency signal when the potential of the third node is the first potential; and

the common voltage signal output unit is connected among the third node, the third reference signal terminal, a fourth reference signal terminal, the common voltage signal terminal, and the touch signal output terminal, and is configured to control the touch signal output terminal to output the common voltage signal when the potential of the third node is the second potential.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the pull-up unit comprises: a fifth switch transistor; wherein

the fifth switch transistor has a gate connected to the control signal output terminal, a source connected to low frequency signal terminal, and a drain connected to the third node.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the pull-down unit comprises: a sixth switch transistor; wherein

the sixth switch transistor has a gate connected to the end signal terminal, a source connected to the third reference signal terminal, and a drain connected to the third node.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the high frequency signal output unit comprises: a seventh switch transistor and a first capacitor; wherein

the seventh switch transistor has a gate connected to the third node, a source connected to the high frequency signal terminal, and a drain connected to the touch signal output terminal; and

the first capacitor is connected between the gate and drain of the seventh transistor.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the common voltage signal output unit comprises: an eight switch transistor and a ninth switch transistor; wherein

the eight switch transistor has a gate connected to the fourth reference signal terminal, a source connected to the common voltage signal terminal, and a drain connected to the touch signal output terminal; and

the ninth switch transistor has a gate connected to the third node, a source connected to the third reference signal terminal, and a drain connected to the fourth reference signal terminal.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the input module comprises: a tenth switch transistor; wherein

the tenth switch transistor has a gate connected to the input signal terminal, a source connected to the first reference signal terminal, and a drain connected to the first node.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the reset module comprises: an eleventh switch transistor; wherein

the eleventh switch transistor has a gate connected to the reset signal terminal, a source connected to the second reference signal terminal, and a source connected to the first node.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the pull-up module comprises: a twelfth switch transistor and a second capacitor; wherein

the twelfth switch transistor has a gate connected to the first node, a source connected to the first clock signal terminal, and a drain connected to the control signal output terminal; and

the second capacitor is connected between the gate and drain of the twelfth switch transistor.

In a possible implementation, in the touch circuit provided in the embodiment of the present disclosure, the pull-down module comprises: a thirteenth switch transistor; wherein

the thirteenth switch transistor has a gate connected to the second node, a source connected to the third reference signal terminal, and a drain connected to the control signal output terminal.

Correspondingly, there is further provided in an embodiment of the present disclosure a touch panel, comprises a plurality of touch circuits connected in cascades provided in the embodiment of the present disclosure; wherein

except for a first stage of touch circuit, control signal output terminals of other stages of touch circuits are all connected to a reset signal terminal of an adjacent previous stage of touch circuit; and

except for a last stage of touch circuit, control signal output terminals of other stages of touch circuits are all connected to a signal input terminal of an adjacent next stage of touch circuit.

Correspondingly, there is provided in an embodiment of the present disclosure a display apparatus, comprising the touch panel provided in the embodiment of the present disclosure.

The touch circuit, the touch panel and the display apparatus provided in the embodiments of the present disclosure comprise: the input module, the reset module, the pull-up module, the pull-down module, the pull-down control module and the touch signal output module; wherein the input module is configured to provide a signal of the first reference signal terminal to the first node under the control of the input signal terminal; the reset module is configured to provide a signal of the second reference signal terminal to the first node under the control of the reset signal terminal; the pull-up module is configured to provide a signal of the first clock signal terminal to the control signal output terminal when a potential of the first node is a first potential; the pull-down module is configured to provide a signal of the third reference signal terminal to the control signal output terminal when a potential of the second node is the first potential; the pull-down control module is configured to provide a signal of the second clock signal terminal to the second node under the control of the second clock signal terminal, control the potential of the second node as a second potential when the potential of the first node is the first potential, and control the potential of the first node as the second potential when the potential of the second node is the first potential; and the touch signal output module is configured to output a high frequency signal or a common voltage signal to a touch signal output terminal under the control of the control signal output terminal. In this way, the function that the touch circuit outputs the touch signal is realized. Compared with touch circuit formed by adopting more thin film transistors to construct a transmission gate, an inverter and a tri-state gate in the prior art, the touch circuit provided in the embodiments of the present disclosure has a simple structure, and relatively low power consumption.

FIG. 1 is a schematic diagram of a structure of a commonly used touch circuit;

FIG. 2 is a schematic diagram of a structure of a touch circuit provided in an embodiment of the present disclosure;

FIG. 3 a is a schematic diagram of a structure of a touch circuit provided in another embodiment of the present disclosure;

FIG. 3 b is a schematic diagram of a structure of a touch circuit provided in another embodiment of the present disclosure;

FIG. 4 a is a schematic diagram of a specific circuit structure of a touch circuit provided in an embodiment of the present disclosure;

FIG. 4 b is a schematic diagram of another specific circuit structure of a touch circuit provided in an embodiment of the present disclosure;

FIG. 5 a is a schematic diagram of another specific circuit structure of a touch circuit provided in an embodiment of the present disclosure;

FIG. 5 b is a schematic diagram of another specific circuit structure of a touch circuit provided in an embodiment of the present disclosure;

FIG. 6 a is a schematic diagram of an operating timing of the touch circuit as shown in FIG. 5 a;

FIG. 6 b is a schematic diagram of an operation timing of the touch circuit as shown in FIG. 5 b;

FIGS. 7 a and 7 b are schematic diagrams of operation timings that touch circuits connected in cascades output touch signals in sequence respectively provided in an embodiment of the present disclosure.

Implementations of a touch circuit, a touch panel and a display apparatus provided in embodiments of the present disclosure will be described in detail below in connection with accompanying figures.

FIG. 1 shows a schematic diagram of a structure of a commonly used touch circuit. As shown in FIG. 1 , touch scan signals on touch scan lines Txn (n=1, 2, 3, . . . ) are transmitted by an external driver (IC) through wirings located in a frame area. However, with the increasing of the size of a display screen, the number of the touch scan lines Txn increases. Then, wirings used for transmitting touch scan signals to the touch scan lines Txn increases correspondingly, thereby resulting in that space occupied by the wirings increases, and applications of in cell technique to a large-size and narrow-frame display screen are limited.

FIG. 2 shows a schematic diagram of a structure of a touch circuit provided in an embodiment of the present disclosure. As shown in FIG. 2 , the touch circuit comprises: an input module 1 , a reset module 2 , a pull-up module 3 , a pull-down module 4 , a pull-down control module 5 and a touch signal output module 6 .

In the touch circuit as shown in FIG. 2 , a control terminal of the input module 1 is connected to a signal input terminal Input, an input terminal thereof is connected to a first reference signal terminal Vref 1 , and an output terminal thereof is connected to a first node P 1 . The input module 1 is configured to provide a signal of the first reference signal terminal Vref 1 to a first node P 1 under the control of the input signal terminal Input.

A control terminal of the reset module 2 is connected to a reset signal terminal Reset, an input terminal thereof is connected to a second reference signal terminal Vref 2 , and an output terminal thereof is connected to the first node P 1 . The reset module 2 is configured to provide a signal of the second reference signal terminal Vref 2 to the first node P 1 under the control of the reset signal terminal Reset.

A control terminal of the pull-up module 3 is connected to the first node P 1 , an input terminal thereof is connected to a first clock signal terminal CK, and an output terminal thereof is connected to a control signal output terminal OUT. The pull-up module 3 is configured to provide a signal of the first clock signal terminal CK to the control signal output terminal OUT when a potential of the first node P 1 is a first potential.

A control terminal of the pull-down module 4 is connected to a second node P 2 , an input terminal thereof is connected to a third reference signal terminal Vref 3 , and an output terminal thereof is connected to the control signal output terminal OUT. The pull-down module 4 is configured to provide a signal of the third reference signal terminal Vref 3 to the control signal output terminal OUT when a potential of the second node P 2 is the first potential.

Respective terminals of the pull-down control module 5 are connected to a second clock signal terminal CKB, the first node P 1 and the second node P 2 respectively. The pull-down control module 5 is configured to provide a signal of the second clock signal terminal CKB to the second node P 2 under the control of the second clock signal terminal CKB, control the potential of the second node P 2 as a second potential when the potential of the first node P 1 is the first potential, and control the potential of the first node P 1 as the second potential when the potential of the second node is the first potential.

A first input terminal of the touch signal output module 6 is connected to the control signal output terminal OUT, a second input terminal thereof is connected to a high frequency signal terminal TH, and a third input terminal thereof is connected to a common voltage signal terminal Vcom. The touch signal output module 6 is used to output a high frequency signal or a common voltage signal to the touch signal output terminal TX under the control of the control signal output terminal OUT;

When an active pulse signal of the input signal terminal Input is a high potential signal, the first potential is a high potential, and the second potential is a low potential; when the active pulse signal of the input signal terminal is a low potential signal, the first potential is a low potential, and the second potential is a high potential; and when the input signal terminal Input starts to output an active pulse signal, the first clock signal terminal CK and the second clock signal terminal CKB output a first potential signal alternatively.

The touch circuit provided in the embodiment of the present disclosure comprises: the input module, the reset module, the pull-up module, the pull-down module, the pull-down control module and the touch signal output module; wherein the input module is configured to provide a signal of the first reference signal terminal to the first node under the control of the input signal terminal; the reset module is configured to provide a signal of the second reference signal terminal to the first node under the control of the reset signal terminal; the pull-up module is configured to provide a signal of the first clock signal terminal to the control signal output terminal when a potential of the first node is a first potential; the pull-down module is configured to provide a signal of the third reference signal terminal to the control signal output terminal when a potential of the second node is the first potential; the pull-down control module is configured to provide a signal of the second clock signal terminal to the second node under the control of the second clock signal terminal, control the potential of the second node as a second potential when the potential of the first node is the first potential, and control the potential of the first node as the second potential when the potential of the second node is the first potential; and the touch signal output module is configured to output a high frequency signal or a common voltage signal to a touch signal output terminal under the control of the control signal output terminal. In this way, the function that the touch circuit outputs the touch signal is realized. Compared with touch circuit formed by adopting more thin film transistors to construct a transmission gate in the prior art, an inverter and a tri-state gate, the touch circuit provided in the embodiments of the present disclosure has a simple structure, and relatively low power consumption.

When implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, when the active pulse signal of the input signal terminal Input is the high potential signal, the signal of the first reference signal terminal is a high potential, and signals of the second reference signal terminal and the third reference signal terminal are both a low potential; when the active pulse signal of the input signal terminal Input is a low potential signal, the signal of the first reference signal terminal is a low potential, and signals of the second reference signal terminal and the third reference signal terminal are both a high potential.

The present disclosure will be described in detail by combining with embodiments. It should be noted that these embodiments of the present disclosure are used to explain the present invention to the better, but not used to limit the protection scope of the present invention.

FIG. 3 a shows a schematic diagram of a structure of a touch circuit provided in another embodiment of the present disclosure. In the touch circuit, as shown in FIG. 3 a , the pull-down control module 5 can comprise: a first pull-down control unit 51 , a second pull-down control unit 52 and a third pull-down control unit 53 .

In FIG. 3 a , a control terminal and an input terminal of the first pull-down control unit 51 are both connected to the second clock signal terminal CKB, and an output terminal thereof is connected to the second node P 2 . The first pull-down control unit 51 is configured to provide the signal of the second clock signal terminal CKB to the second node P 2 under the control of the second clock signal terminal CKB.

A control terminal of the second pull-down control unit 52 is connected to the first node P 1 , an input terminal thereof is connected to a third reference signal terminal Vref 3 , and an output terminal thereof is connected to the second node P 2 . The second pull-down control unit 52 is configured to provide a signal of the third reference signal terminal Vref 3 to the second node P 2 when the potential of the first node P 1 is the first potential.

A control terminal of the third pull-down control unit 53 is connected to the second node P 2 , an input terminal thereof is connected to the third reference signal terminal Vre 3 , and an output terminal thereof is connected to the first node P 1 . The third pull-down control unit 53 is configured to provide the signal of the third signal terminal Vref 3 to the first node P 1 when the potential of the second node P 2 is the first potential.

When implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, when the potential of the first node is the first potential, the second pull-down control unit provides the signal of the third reference signal terminal to the second node, such that the potential of the second node is the second potential; and the first pull-down control unit provides the signal of the second clock signal terminal to the second node when the signal of the second clock signal terminal is the first potential, such that the potential of the second node is the first potential; when the potential of the second node is the first potential, the third pull-down control unit provides the signal of the third reference signal terminal to the first node, such that the potential of the first node is the second potential, thereby realizing that the potential of only one node of the first node and the second node is the first potential at a same moment, and thus ensuring normal and stable output of the control signal output terminal.

FIG. 3 b shows a schematic diagram of a structure of a touch circuit provided in yet another embodiment of the present disclosure. As shown in FIG. 3 b , further, in the touch circuit provided in the embodiment of the present disclosure, the pull-down control module 5 can further comprise: a fourth pull-down control unit 54 .

In FIG. 3 b , a control terminal of the fourth pull-down control unit 54 is connected to the control signal output terminal OUT, an input terminal thereof is connected to the third reference signal terminal Vref 3 , and an output terminal thereof is connected to the second node P 2 . The fourth pull-down control unit 54 is configured to provide the signal of the third reference signal terminal Vref 3 to the second node P 2 when the potential of the control signal output terminal OUT is the first potential, thereby further ensuring stability of the signal of the control signal output terminal.

FIGS. 4 a and 4 b show schematic diagrams of a specific circuit structure of a touch circuit provided in an embodiment of the present disclosure respectively. Exemplarily, as shown in FIGS. 4 a and 4 b , in the touch circuit provided in the embodiment of the present disclosure, the first pull-down control unit 51 can comprise: a first switch transistor T 1 .

Both a gate and a source of the first switch transistor T 1 are connected to the second clock signal terminal CKB, and a drain thereof is connected to the first node P 1 .

In the touch circuit provided in the embodiment of the present disclosure, when the first switch transistor is in a turn-on state under the control of the second clock signal terminal, the signal of the second clock signal terminal is provided to the first node.

Further, when implementing specifically, in the touch circuit provided in the embodiments of the present disclosure, as shown in FIG. 4 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the first switch transistor T 1 is a N-type transistor. Or, as shown in FIG. 4 b , when the active pulse signal of the input signal terminal Input is a low potential signal, the first switch transistor T 1 is a P-type transistor.

Specifically, the N-type transistor is in the turn-on state when its gate potential is a high potential, and is in a turn-off state when its gate potential is a low potential; the P-type transistor is in the turn-on state when its gate potential is a low potential, and is in a turn-off state when its gate potential is a high potential.

The above description just takes an example to describe the specific structure of the first pull-down control unit in the touch circuit. When implementing specifically, the specific structure of the first pull-down control unit is not limited to the above structure provided in the embodiment of the present disclosure, and may be other structures known by those skilled in the art, to which no limitation is given herein.

Exemplarily, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 4 a and 4 b , the second pull-down control unit 52 can comprise: a second switch transistor T 2 .

A gate of the second switch transistor T 2 is connected to the first node P 1 , a source thereof is connected to the third reference signal terminal Vref 3 , and a drain thereof is connected to the second node P 2 .

In particular, in the touch circuit provided in the embodiment of the present disclosure, when the second switch transistor is in the turn-on state under the control of the first node, the signal of the third reference signal terminal is provided to the second node.

Further, when implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 4 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the second switch transistor T 2 is the N-type transistor. Or, as shown in FIG. 4 b , when the active pulse signal of the input signal input Input is a low potential signal, the second switch transistor T 2 is the P-type transistor.

The above description just takes an example to describe the specific structure of the second pull-down control unit in the touch circuit. When implementing specifically, the specific structure of the second pull-down control unit is not limited to the above structure provided in the embodiment of the present disclosure, and may be other structures known by those skilled in the art, to which no limitation is given herein.

Exemplarily, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 4 a and 4 b , the third pull-down control unit 53 can comprise: a third switch transistor T 3 .

A gate of the second switch transistor T 3 is connected to the second node P 2 , a source thereof is connected to the third reference signal terminal Vref 3 , and a drain thereof is connected to the first node P 1 .

In particular, in the touch circuit provided in the embodiment of the present disclosure, when the third switch transistor is in the turn-on state under the control of the second node, the signal of the third reference signal terminal is provided to the first node.

Further, when implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 4 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the third switch transistor T 3 is the N-type transistor. Or, as shown in FIG. 4 b , when the active pulse signal of the input signal input Input is a low potential signal, the third switch transistor T 3 is the P-type transistor.

The above description just takes an example to describe the specific structure of the third pull-down control unit in the touch circuit. When implementing specifically, the specific structure of the third pull-down control unit is not limited to the above structure provided in the embodiment of the present disclosure, and may be other structures known by those skilled in the art, to which no limitation is given herein.

Exemplarily, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 4 a and 4 b , the fourth pull-down control unit 54 can comprise: a fourth switch transistor T 4 .

A gate of the fourth switch transistor T 4 is connected to the control signal output terminal OUT, a source thereof is connected to the third reference signal terminal Vref 3 , and a drain thereof is connected to the second node P 2 .

In particular, in the touch circuit provided in the embodiment of the present disclosure, when the fourth switch transistor is in the turn-on state under the control of the control signal output terminal, the signal of the third reference signal terminal is provided to the second node.

Further, when implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 4 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the fourth switch transistor T 4 is the N-type transistor. Or, as shown in FIG. 4 b , when the active pulse signal of the input signal input Input is a low potential signal, the fourth switch transistor T 4 is the P-type transistor.

The above description just takes an example to describe the specific structure of the fourth pull-down control unit in the touch circuit. When implementing specifically, the specific structure of the fourth pull-down control unit is not limited to the above structure provided in the embodiment of the present disclosure, and may be other structures known by those skilled in the art, to which no limitation is given herein.

In specific implementation, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 3 a , the touch signal output module 6 can comprise: a high frequency signal output unit 61 , a common voltage signal output unit 62 , a pull-up unit 63 and a pull-down unit 64 .

A control terminal of the pull-up unit 63 is a first input terminal of the touch signal output module 6 , an input terminal thereof is connected to a low frequency signal terminal TL, and an output terminal thereof is connected to a third node P 3 ; the pull-up unit 63 is configured to provide a signal of the low frequency signal terminal TL to the third node P 3 when the potential of the control signal output terminal OUT is the first potential.

A control terminal of the pull-down unit 64 is connected to an end signal terminal END, an input terminal thereof is connected to the third node P 3 , and an output terminal thereof is connected to the third reference signal terminal Vref 3 . The pull-down unit 64 is configured to provide the signal of the third reference signal terminal Vref 3 to the third node P 3 under the control of the end signal terminal END.

A control terminal of the high frequency signal output terminal 61 is connected to the third node P 3 , an input terminal thereof is connected to a second input terminal of the touch signal output module 6 , and an output terminal thereof is connected to a touch signal output terminal TX. The high frequency signal output unit 61 is configured to control the touch signal output terminal TX to output a high frequency signal when the potential of the third node P 3 is the first potential.

The common voltage signal output unit 62 is connected among the third node P 3 , the third reference signal terminal Vref 3 , a fourth reference signal terminal Vref 4 , the common voltage signal terminal Vcom, and the touch signal output terminal TX. The common voltage signal output terminal 62 is configured to control the touch signal output terminal TX to output a common voltage signal when the potential of the third node P 3 is the second potential.

Further, in the touch circuit provided in the embodiment of the present disclosure, when a signal of the third reference signal terminal is a high potential, the signal of the fourth reference signal terminal is a low potential; when the signal of the third reference signal terminal is a low potential, the signal of the fourth reference signal is a high potential.

In particular, in the touch circuit provided in the embodiment of the present disclosure, when the potential of the control signal output terminal is the first potential, the pull-up unit provides the signal of the low frequency signal terminal to the third node. When the signal of the end signal terminal is the first potential, the pull-down unit provides the signal of the third reference signal terminal to the third node. When the potential of is the third node is the first potential, the high frequency signal output unit controls the touch signal output terminal to output a high frequency signal; when the potential of the third node is the second potential, the common voltage signal output unit controls the touch signal output terminal to output a common voltage signal. In this way, the function that the touch signal output module selects to output the high frequency signal or the common voltage signal under the control of the control signal output terminal is realized.

It should be noted that in the touch circuit provided in the embodiment of the present disclosure, a pulse width of the low frequency signal inputted by the low frequency signal terminal is at least two times of a pulse width of the high frequency inputted by the high frequency signal terminal. When the touch signal output terminal outputs the high frequency signal, the pulse width of the low frequency signal inputted by the low frequency signal terminal makes a sample selection of the high frequency signal outputted by the touch signal output terminal, which determines how many high frequency signals outputted at each time when the touch signal output terminal outputs the high frequency signal. For example, if the pulse width of the low frequency signal is two times of the pulse width of the high frequency signal, then two high frequency signals are outputted at each time when the touch signal output terminal TX outputs the high frequency signal.

Exemplarily, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 4 a and 4 b , the pull-up unit 63 can comprise: a fifth switch transistor T 5 .

A gate of the fifth switch transistor T 5 is connected to the control signal output terminal OUT, a source thereof is connected to the low frequency signal terminal TL, and a drain thereof is connected to the third node P 3 .

In the touch circuit provided in the embodiment of the present disclosure, when the fifth switch transistor T 5 is in the turn-on state under the control of the control signal output terminal, the signal of the low frequency terminal is provided to the third node P 3 .

Further, when implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 4 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the fifth switch transistor T 5 is a N-type transistor. Or, as shown in FIG. 4 b , when the active pulse signal of the input signal terminal Input is a low potential signal, the fifth switch transistor T 5 is a P-type transistor.

The above description just takes an example to describe the specific structure of the pull-up unit in the touch circuit. When implementing specifically, the specific structure of the pull-up unit is not limited to the above structure provided in the embodiment of the present disclosure, and may be other structures known by those skilled in the art, to which no limitation is given herein.

Exemplarily, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 4 a and 4 b , the pull-down unit 64 can comprise: a sixth switch transistor T 6 .

A gate of the sixth switch transistor T 6 is connected to the end signal terminal END, a source thereof is connected to the third reference signal terminal Vref 3 , and a drain thereof is connected to the third node P 3 .

In the touch circuit provided in the embodiment of the present disclosure, when the sixth switch transistor T 6 is in the turn-on state under the control of the end signal terminal END, the signal of the third reference signal terminal Vref 3 is provided to the third node P 3 .

Further, when implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 4 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the sixth switch transistor T 6 is the N-type transistor. Or, as shown in FIG. 4 b , when the active pulse signal of the input signal input Input is a low potential signal, the sixth switch transistor T 6 is the P-type transistor.

The above description just takes an example to describe the specific structure of the pull-down unit in the touch circuit. When implementing specifically, the specific structure of the pull-down unit is not limited to the above structure provided in the embodiment of the present disclosure, and may be other structures known by those skilled in the art, to which no limitation is given herein.

Exemplarily, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 4 a and 4 b , the high frequency signal output unit 61 can comprise: a seventh switch transistor T 7 and a first capacitor C 1 .

A gate of the seventh switch transistor T 7 is connected to the third node P 3 , a source thereof is connected to the high frequency signal terminal TH, and a drain thereof is connected to the touch signal output terminal TX.

The first capacitor C 1 is connected between the gate and drain of the seventh switch transistor T 7 .

In the touch circuit provided in the embodiment of the present disclosure, when the seventh switch transistor is in the turn-on state under the control of the third node P 3 , the signal of the high frequency signal terminal TH is provided to the touch signal output terminal TX, so that the touch signal output terminal TX outputs the high frequency signal.

Further, when implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 4 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the seventh switch transistor T 7 is the N-type transistor. Or, as shown in FIG. 4 b , when the active pulse signal of the input signal input Input is a low potential signal, the seventh switch transistor T 7 is the P-type transistor.

The above description just takes an example to describe the specific structure of the high frequency signal output unit in the touch circuit. When implementing specifically, the specific structure of the high frequency signal output unit is not limited to the above structure provided in the embodiment of the present disclosure, and may be other structures known by those skilled in the art, to which no limitation is given herein.

Exemplarily, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 4 a and 4 b , the common voltage signal output unit 62 can comprise: an eighth switch transistor T 8 and a ninth switch transistor T 9 .

A gate of the eighth switch transistor T 8 is connected to the fourth reference signal terminal Vref 4 , a source thereof is connected to the common voltage signal terminal Vcom, and a drain thereof is connected to the touch signal output terminal TX;

A gate of ninth switch transistor T 9 is connected to the third node P 3 , a source thereof is connected to the third reference signal terminal Vref 3 , and a drain thereof is connected to the fourth reference signal terminal Vref 4 .

In the touch circuit provided in the embodiment of the present disclosure, when the potential of the third node is the first potential, the ninth switch transistor T 9 is in the turn-on state, the turned on ninth switch transistor T 9 connects the gate of the eighth switch transistor T 8 with the third reference signal terminal Vref 3 , such that the eighth switch transistor T 8 is turned off, and the ninth switch transistor T 9 has a relatively large size, which would increase its function of voltage dividing, and would pull down the gate voltage of the eighth switch transistor T 8 to the better, so as to ensure that the eighth switch transistor T 8 is in a complete turn-off state. When the potential of the third node P 3 is the second potential, the ninth switch transistor T 9 is in the turn-off state. Since the gate of the eight switch transistor T 8 is connected to the fourth reference signal terminal, the eighth switch transistor T 8 is in the turn-on state. The turned on eighth switch transistor T 8 connects the common voltage signal terminal with the touch signal output terminal, so that the touch signal output terminal outputs the common voltage signal.

Further, when implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 4 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the eighth switch transistor T 8 and the ninth switch transistor T 9 are N-type transistors. Or, as shown in FIG. 4 b , when the active pulse signal of the input signal input Input is a low potential signal, the eighth switch transistor T 8 and the ninth switch transistor T 9 are the P-type transistors.

Further, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 5 a and 5 b , the common voltage signal output unit 62 can further comprise: a third capacitor C 3 , which is connected between the gate and drain of the eighth switch transistor T 8 . Herein, the third capacitor C 3 mainly functions as filtering and voltage stabilizing, so as to ensure stability of the touch signal output terminal.

Further, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 5 a and 5 b , the common voltage signal output terminal 62 can further comprise: s fourteenth switch transistor T 14 .

Both a gate and a source of the fourteenth switch transistor T 14 are connected to the fourth reference signal terminal Vref 4 , and a drain thereof is connected to the gate of the eighth switch transistor T 8 and the drain of the ninth switch transistor T 9 respectively.

In particular, in the touch circuit provided in the embodiment of the present disclosure, the fourteenth switch transistor T 14 connects the fourth reference signal terminal Vref 4 to the gate of the eighth switch transistor T 8 and the drain of the ninth switch transistor T 9 in a diode connecting manner, and is always in a normal turn-on state. When the ninth switch transistor T 9 is in the turn-off state, the signal inputted by the fourth reference signal terminal Vref 4 is provided to the gate of the eighth switch transistor T 8 , so that the eighth switch transistor T 8 is in the turn-on state. The turned on eighth switch transistor T 8 connects the common voltage signal terminal Vcom with the touch signal output terminal TX, so that the touch signal output terminal TX outputs the common voltage signal.

Further, when implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 5 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the fourteenth switch transistor T 14 is a N-type transistor. Or, as shown in FIG. 5 b , when the active pulse signal of the input signal terminal Input is a low potential signal, the fourteenth switch transistor T 14 is a P-type transistor.

The above description just takes an example to describe the specific structure of the common voltage signal output unit in the touch circuit. When implementing specifically, the specific structure of the common voltage signal output unit is not limited to the above structure provided in the embodiment of the present disclosure, and may be other structures known by those skilled in the art, to which no limitation is given herein.

Exemplarily, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 4 a and 4 b , the input module 1 can comprise: a tenth switch transistor T 10 .

A gate of the tenth switch transistor T 10 is connected to the input signal terminal Input, a source thereof is connected to the first reference signal terminal Vref 1 , and a drain thereof is connected to the first node P 1 .

In the touch circuit provided in the embodiment of the present disclosure, when the tenth switch transistor T 10 is in the turn-on state under the control of the input signal terminal, the signal of the first reference signal terminal Vref 1 is provided to the first node P 1 .

Further, when implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 4 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the tenth switch transistor T 10 is the N-type transistor. Or, as shown in FIG. 4 b , when the active pulse signal of the input signal input Input is a low potential signal, the tenth switch transistor T 10 is the P-type transistor.

The above description just takes an example to describe the specific structure of the input module in the touch circuit. When implementing specifically, the specific structure of the input module is not limited to the above structure provided in the embodiment of the present disclosure, and may be other structures known by those skilled in the art, to which no limitation is given herein.

Exemplarily, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 4 a and 4 b , the reset module 2 can comprise: an eleventh switch transistor T 11 .

A gate of the eleventh switch transistor T 11 is connected to the reset signal terminal Reset, a source thereof is connected to the second reference signal terminal Vref 2 , and a drain thereof is connected to the first node P 1 .

In the touch circuit provided in the embodiment of the present disclosure, when the eleventh switch transistor T 11 is in the turn-on state under the control of the reset signal terminal, the signal of the second reference signal terminal is provided to the first node.

Further, when implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 4 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the eleventh switch transistor T 11 is the N-type transistor. Or, as shown in FIG. 4 b , when the active pulse signal of the input signal input Input is a low potential signal, the eleventh switch transistor T 11 is the P-type transistor.

The above description just takes an example to describe the specific structure of the reset module in the touch circuit. When implementing specifically, the specific structure of the reset module is not limited to the above structure provided in the embodiment of the present disclosure, and may be other structures known by those skilled in the art, to which no limitation is given herein.

Exemplarily, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 4 a and 4 b , the pull-up module 3 can comprise: a twelfth switch transistor T 12 and a second capacitor C 2 .

A gate of the twelfth switch transistor T 12 is connected to the first node P 1 , a source thereof is connected to the first clock signal terminal CK, and a drain thereof is connected to the control signal output terminal OUT.

The second capacitor C 2 is connected between the gate and drain of the twelfth switch transistor T 12 .

In the touch circuit provided in the embodiment of the present disclosure, when the twelfth switch transistor T 12 is in the turn-on state under the control of the first node P 1 , the signal of the first clock signal terminal is provided to the control signal terminal.

Further, when implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 4 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the twelfth switch transistor T 12 is the N-type transistor. Or, as shown in FIG. 4 b , when the active pulse signal of the input signal input Input is a low potential signal, the twelfth switch transistor T 12 is the P-type transistor.

The above description just takes an example to describe the specific structure of the pull-up module in the touch circuit. When implementing specifically, the specific structure of the pull-up module is not limited to the above structure provided in the embodiment of the present disclosure, and may be other structures known by those skilled in the art, to which no limitation is given herein.

Exemplarily, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 4 a and 4 b , the pull-down module 4 can comprise: a thirteenth switch transistor T 13 .

A gate of the thirteenth switch transistor T 13 is connected to the second node P 2 , a source thereof is connected to the third reference signal terminal Vref 3 , and a drain thereof is connected to the control signal output terminal OUT.

In the touch circuit provided in the embodiment of the present disclosure, when the thirteenth switch transistor T 13 is in the turn-on state under the control of the second node P 2 , the signal of the third reference signal terminal Vref 3 is provided to the control signal output terminal.

Further, when implementing specifically, in the touch circuit provided in the embodiment of the present disclosure, as shown in FIG. 4 a , when the active pulse signal of the input signal terminal Input is a high potential signal, the thirteenth switch transistor T 13 is the N-type transistor. Or, as shown in FIG. 4 b , when the active pulse signal of the input signal input Input is a low potential signal, the thirteenth switch transistor T 13 is the P-type transistor.

Further, as shown in FIGS. 5 a and 5 b , in the touch circuit provided in the embodiment of the present disclosure, the pull-down module 4 can further comprise: a fourth capacitor C 4 , which is connected between the gate and drain of the thirteenth switch transistor 113 . Herein, the fourth capacitor C 4 mainly functions as filtering and voltage stabilizing, so as to ensure stability of the touch signal output terminal.

The above description just takes an example to describe the specific structure of the pull-clown module in the touch circuit. When implementing specifically, the specific structure of the pull-down module is not limited to the above structure provided in the embodiment of the present disclosure, and may be other structures known by those skilled in the art, to which no limitation is given herein.

It should be noted that the switch transistors mentioned in the embodiments of the present disclosure may be thin film transistors (TFT), or may be metal oxide semiconductor (MOS), to which no limitation is given herein. In a specific implementation, functions of sources and drains of these switch transistors can be exchanged with each other depending on different types of transistors and input signals, to which no distinction is made herein.

In the touch circuit provided in the embodiment of the present disclosure, as shown in FIGS. 4 a and 5 a , when the active pulse signal of the input signal is a high potential signal, all the switch transistors are N-type transistors; as shown in FIGS. 4 b and 5 b , when the active pulse signal of the input signal is a low potential signal, all the switch transistors are P-type transistors. In this way, an integrated touch circuit design with a single transistor structure is provided. Compared with the touch circuit constituted of the N-type transistors and the P-type transistors in the prior art, the touch circuits provided in the embodiments of the present disclosure have high development reliability, simple structure, and few number of switch transistors, which saves space for the design, and is more advantageous for a narrow frame of a display product.

In the touch circuit provided in the embodiment of the present disclosure, since all the respective modules can be constituted of N-type thin film transistors, i.e., totally fourteenth NMOS transistors and four capacitors are needed to form the touch circuit, they match with the N-type thin film transistor driving circuit used to drive the display panel to realize the display function in the display panel in a better way. Compared with the touch circuit formed by adopting more thin film transistors to construct transmission gates, inverters and tri-state gate circuits in the prior art, the touch circuit provided in the embodiments of the present disclosure adopts less number of N-type thin film transistors. Therefore, the touch circuits provided in the embodiments of the present disclosure have simple structure and low power consumption.

Based on the same inventive concept, there is provided in an embodiment of the present disclosure a touch panel, comprising a plurality of touch circuits connected in cascades provided in an embodiment of the present disclosure.

In the touch panel, except a first stage of touch circuit, control signal output terminals of other stages of touch circuits are connected to a reset signal terminal of an adjacent previous stage of touch circuit; and

except a last stage of touch circuit, control signal output terminals of other stages of touch circuits are connected to a signal input terminal of an adjacent next stage of touch circuit.

FIG. 6 a shows a schematic diagram of an operation timing of the touch circuit as shown in FIG. 5 a , and FIG. 6 b shows a schematic diagram of an operation timing of the touch circuit as shown in FIG. 5 b

Operation process of the touch circuit will be described in detail in combination with FIGS. 6 a , 6 b and 7 by taking respectively the touch circuits as shown in FIGS. 4 a to 5 b as an example. The description below uses 1 to represent a high potential signal, and uses 0 to represent a low level signal.

In the touch circuit as shown in FIG. 5 a , the active pulse signal of the input signal terminal Input is a high potential signal, a first potential is a high potential, a second potential is a low potential, signals of the first reference signal terminal Vref 1 and the fourth reference signal terminal Vref 4 are the high potential, signals of the second reference signal terminal Vref 1 and the third reference signal terminal Vref 1 are the low potential, all the switch transistors are N-type transistors, and the corresponding input/output timing diagrams are shown in FIG. 6 a . In particular, phases T 1 and T 2 in the input/output timing diagram as shown in FIG. 6 a are selected.

In phase T 1 , Input=1, T 1 =1, CK=1, CKB=0, Reset=0, END=0. Since Input=1, the tenth switch transistor T 10 is turned on. The turned on tenth switch transistor T 10 provides the signal of the first reference signal terminal Vref 1 having the high potential to the first node P 1 . Therefore, the potential of the first node P 1 is the high potential, so that the twelfth switch transistor T 12 and the second switch transistor T 2 are turned on. The turned on second switch transistor T 2 provides the signal of the third reference signal terminal Vref 3 having the low potential to the second node P 2 . Therefore, the potential of the second node P 2 is the low potential, so that the third switch transistor T 3 and the thirteenth switch transistor T 13 are turned off. The turned on twelfth switch transistor T 12 connects the first clock signal terminal CK to the control signal output terminal OUT. Since CK= 1 , the potential of the control signal output terminal OUT is the high potential, so that the fifth switch transistor T 5 and the fourth switch transistor T 4 are in the turn-on state. The turned on fourth switch transistor T 4 connects the third reference signal terminal Vref 3 having the low potential to the second node P 2 , thereby further ensuring that the potential of the second node P 2 is the low potential, and the turned on fifth switch transistor T 5 connects the low frequency signal terminal TL with the third node P 3 . Since TL=1, the potential of the third node P 3 is the high potential, so that the ninth switch transistor T 9 and the seventh switch transistor T 7 are in the turn-on state. The turned on ninth switch transistor T 9 connects the third reference signal terminal Vref 3 having the low potential to the gate of the eighth switch transistor T 8 and the drain of the fourteenth switch transistor T 14 . Therefore, the eighth switch transistor T 8 is turned off, and the turned on seventh switch transistor T 7 connects the high frequency signal terminal TH to the touch signal output terminal TX, so that the touch signal output terminal TX outputs a high frequency signal according to a pulse width of a low frequency signal inputted by the low frequency signal terminal TL.

That is, the phase T 1 is a phase where the touch signal output terminal TX outputs the high frequency signal.

In phase T 2 , Input=0, TL=1, CK=0, CKB=1, Reset=1, END=1. Since Reset=1, the eleventh switch transistor T 11 is turned on. The turned on eleventh switch transistor T 1 connects the second reference signal terminal Vref 2 having the low potential to the first node P 1 . Therefore, the potential of the first node P 1 is the low potential. Since CKB=1, the first switch transistor T 1 is turned on. The turned on first switch transistor T 1 connects the second clock signal terminal CKB to the second node P 2 . Therefore, the potential of the second node P 2 becomes the high potential, so that the thirteenth switch transistor T 13 and the third switch transistor T 3 are turned on. The turned on third switch transistor T 3 provides the signal of the third reference signal terminal Vref 3 having the low potential to the first node P 1 , and the turned on thirteen switch transistor T 13 connects the control signal output terminal OUT to the third reference signal terminal Vref 3 having the low potential. Therefore, the potential of the control signal output terminal OUT is the low potential, so that the fifth switch transistor T 5 is turned off. Since END=1, the sixth switch transistor T 6 is turned on. The turned on sixth switch transistor T 6 provides the signal of the third reference signal terminal Vref 3 having the low potential to the third node P 3 . Therefore, the potential of the third node P 3 is the low potential, and the ninth switch transistor T 9 and the seventh switch transistor T 7 are turned off. Since the fourteenth switch transistor T 14 is in a normal turn-on state, and at this time, the ninth switch transistor T 9 is in the turn-off state, thus the gate of the eighth switch transistor T 8 is connected to the fourth reference signal terminal Vref 4 having the high potential through the fourteenth switch transistor T 14 . Therefore, the eighth switch transistor T 8 is turned on. The turned on eighth switch transistor T 8 connects the common voltage signal terminal VCOM to the touch signal output terminal TX, so that the touch signal output terminal TX outputs the common voltage signal.

That is, the phase T 2 is a phase where the touch signal output terminal TX outputs the common voltage signal.

In subsequent periods of time, the touch signal output terminal would constantly output the common voltage signal until the active pulse signal of the signal input terminal Input is the high potential signal.

The above process is an operation process that one touch circuit outputs the high frequency signal and the common voltage signal respectively. In the entire touch circuits of the touch panel connected in cascades, under the control of respective signal control terminals, each stage of touch circuit outputs the high frequency signal or the common voltage signal respectively according to the above operation process as shown in FIG. 7 a, which finally realizes the function that the touch circuits output the high frequency signal stage by stage, i.e., realizing the process of progressive touch scanning of the touch panel.

In the touch circuit as shown in FIG. 5 b , the active pulse signal of the input signal terminal Input is the low potential signal, the first potential is the low potential, the second potential is the high potential, signals of the first reference signal terminal Vref 1 and the fourth reference signal terminal Vref 4 are the low potential, signals of the second reference signal terminals Vref 2 and the third reference signal terminals Vref 3 are the high potential, all the switch transistors are N-type transistors, and the corresponding input/output timing diagram is shown in FIG. 6 b . In particular, phases T 1 and T 2 in the input/output timing diagram as shown in FIG. 6 b are selected.

In phase T 1 , Input=0, TL=0, CK=0, CKB=1, Reset=1, END=1. Since Input=0, the tenth switch transistor T 10 is turned on. The turned on tenth switch transistor T 10 connects the first reference signal terminal Vref 1 having the low potential to the first node P 1 . Therefore, the potential of the first node P 1 is the low potential, so that the twelfth switch transistor T 12 and the second switch transistor T 2 are turned on. The turned on second switch transistor T 2 connects the third reference signal terminal Vref 3 having the high potential to the second node P 2 . Therefore, the potential of the second node P 2 is the high potential, so that the third switch transistor T 3 and the thirteenth switch transistor T 13 are turned off. The turned on twelfth switch transistor T 12 connects the first clock signal terminal CK to the control signal output terminal OUT. Since CK=0, the potential of the control signal output terminal OUT is the low potential, so that the fifth switch transistor T 5 and the fourth switch transistor 14 are in the turn-on state. The turned on fourth switch transistor T 4 connects the third reference signal terminal Vref 3 having the low potential to the second node P 2 , thereby further ensuring that the potential of the second node P 2 is the high potential, and the turned on fifth switch transistor T 5 connects the low frequency signal terminal TL to the third node P 3 . Since TL=0, the potential of the third node P 3 is the low potential, so that the ninth switch transistor 19 and the seventh switch transistor T 7 are in the turn-on state. The turned on ninth switch transistor 19 connects the third reference signal terminal Vref 3 having the high potential to the gate of the eighth switch transistor T 8 and the drain of the fourteenth switch transistor T 14 . Therefore, the eighth switch transistor T 8 is turned off, and the turned on seventh switch transistor T 7 connects the high frequency signal terminal TH to the touch signal output terminal TX, so that the touch signal output terminal TX outputs a high frequency signal according to a pulse width of a low frequency signal inputted by the low frequency signal terminal TL.

That is, the phase T 1 is a phase where the touch signal output terminal TX outputs the low frequency signal.

In phase T 2 , Input=1, TL=0, CK=1, CKB=0, Reset=0, END=0. Since Reset=1, the eleventh switch transistor T 11 is turned on. The turned on eleventh switch transistor T 1 connects the second reference signal terminal Vref 2 having the high potential to the first node P 1 . Therefore, the potential of the first node P 1 is the high potential. Since CKB=1, the first switch transistor T 1 is turned on. The turned on first switch transistor T 1 connects the second clock signal terminal CKB to the second node P 2 . Therefore, the potential of the second node P 2 becomes the low potential, so that the thirteenth switch transistor T 13 and the third switch transistor T 3 are turned on. The turned on third switch transistor T 3 provides the signal of the third reference signal terminal Vref 3 having the high potential to the first node P 1 , and the turned on thirteen switch transistor T 13 connects the control signal output terminal OUT to the third reference signal terminal Vref 3 having the high potential. Therefore, the potential of the control signal output terminal OUT is the high potential, so that the fifth switch transistor T 5 is turned off. Since END=0, the sixth switch transistor T 6 is turned on. The turned on sixth switch transistor T 6 provides the signal of the third reference signal terminal Vref 3 having the high potential to the third node P 3 . Therefore, the potential of the third node P 3 is the high potential, and the ninth switch transistor T 9 and the seventh switch transistor T 7 are turned off. Since the fourteenth switch transistor T 14 is in a normal turn-on state, and at this time, the ninth switch transistor T 9 is in the turn-off state, thus the gate of the eighth switch transistor T 8 is connected to the fourth reference signal terminal Vref 4 having the low potential through the fourteenth switch transistor T 14 . Therefore, the eighth switch transistor T 8 is turned on. The turned on eighth switch transistor T 8 connects the common voltage signal terminal VCOM with the touch signal output terminal TX, so that the touch signal output terminal TX outputs the common voltage signal.

That is, the phase T 2 is a phase where the touch signal output terminal TX outputs the common voltage signal.

In subsequent periods of time, the touch signal output terminal will constantly output the common voltage signal until the active pulse signal of the signal input terminal Input is the low potential signal.

The above process is an operation process that one touch circuit outputs the high frequency signal and the common voltage signal respectively. In the entire touch circuits of the touch panel connected in cascades, under the control of respective signal control terminals, each stage of touch circuit outputs the high frequency signal or the common voltage signal according to the above operation process respectively as shown in FIG. 7 b, which finally realizes the function that the touch circuits output the high frequency signal stage by stage, i.e., realizing the process of progressive touch scanning of the touch panel.

Based on the same inventive concept, there is provided in an embodiment of the present disclosure a display apparatus, comprising the touch panel provided in the embodiment of the present disclosure. The display apparatus can be applicable to any product or elements having display function, such as a mobile phone, a tablet computer, a television set, a display, a notebook computer, a digital frame, and a navigator or the like. Since the principle of the display apparatus for solving the problem is similar to that of the touch circuit, the implementation of the display apparatus can refer to the implementation of the touch circuit described above, and thus no further description is given herein.

The touch circuit, the touch panel and the display apparatus provided in the embodiments of the present disclosure realize the function that the touch circuit outputs the touch signal. Compared with the touch circuit formed by adopting more thin film transistors to construct a transmission gate, an inverter and a tri-state gate circuit in the prior art, the touch circuit provided in the embodiment of the present disclosure has simple structure and low power consumption.

Obviously, those skilled in the art can make various alternations and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. As such, if these alternations and modifications of the present disclosure belong to the scope of the claims of the present disclosure, the present disclosure also intend to cover these alternations and modifications.

The present application claims the priority of a Chinese patent application No. 201510243727.7 filed on May 13, 2015. Herein, the content disclosed by the Chinese patent application is incorporated in full by reference as a part of the present disclosure.