Touch circuit and touch sensing device

Abstract

The present invention relates to a touch circuit for stably maintaining an output voltage level by using a transistor, the touch circuit comprising: a first driving transistor (T1) having a drain electrode and a gate electrode that are connected to an input power source (VDD), and having a source electrode that is connected to a drain electrode of a second driving transistor (T2); and the T2 having a gate electrode that is connected to one electrode of a capacitive element with the other electrode connected to the VDD, having the drain electrode connected to the source electrode of the T1, and having the source electrode connected to the ground, and further comprising a reset transistor (Tr) having a drain electrode and a gate electrode that are connected to the VDD, and having a source electrode that is connected to the gate electrode of the T2.

Description

Touch circuit and touch sensing device

[0001] The present invention relates to a touch circuit and a touch sensing device, and more particularly, to a touch circuit and a touch sensing device capable of quickly recovering an output voltage to a ground voltage when a touch is released, thereby providing a stable and reliable output.

[0002] Touch sensors are a technology used in touch panels or touchscreens to directly receive input from the user's touch. These touch sensors are used not only in smartphones but also in various display products, including tablet PCs (Personal Computers), laptop PCs, AIO (All-in-One) PCs, and DIDs (Digital Information Displays). Their applications are expanding beyond IT (Information Technology) products into other sectors, such as the automotive market.

[0003] Touch sensors are utilized in a variety of applications, including bank teller machines and digital door locks. Small capacitive circuits are also being used in applications such as fingerprint recognition. Touch sensor technology currently utilizes single-electrode layer touch sensors, flexible touch sensors, embedded touch sensors, large-area touch sensors, and multi-functional fusion / composite structures that incorporate fingerprint recognition and tigtizers.

[0004] In this way, the ability to detect touch is becoming increasingly stronger, and fingerprint recognition technology is beginning to be widely used. Touch sensors that can be used as general touch sensors are being proposed, but there is a problem that the reliability and accuracy of the sensor may decrease when the distance between the sensor and the touch increases.

[0005] [Prior Art Literature]

[0006] [Patent Document] Korean Patent No. 10-1728627 (Publication Date: April 19, 2017)

[0007] The purpose of the present invention is to provide a touch circuit and a touch sensing device that can secure stability and reliability by quickly recovering the output voltage to the ground voltage when the touch is released.

[0008] In order to achieve the above purpose, according to one embodiment, a touch circuit,

[0009] In a touch circuit that stably maintains an output voltage level using a transistor,

[0010] A first driving transistor (T1) having a drain electrode and a gate electrode connected to an input power supply (VDD), and a source electrode connected to a drain electrode of a second driving transistor (T2); and a second driving transistor (T2) having a gate electrode connected to the other electrode of a capacitor element, one electrode of which is connected to the input power supply (VDD), a drain electrode connected to the source electrode of the first driving transistor (T1), and a source electrode connected to ground;

[0011] It is characterized by including a reset transistor (Tr) whose drain electrode and gate electrode are connected to the input power supply (VDD) and whose source electrode is connected to the gate electrode of the second driving transistor (T2).

[0012] A touch circuit according to another embodiment for achieving the above purpose is:

[0013] In a touch circuit that stably maintains an output voltage level using a transistor,

[0014] A first driving transistor (T1) having a drain electrode and a gate electrode connected to a source electrode of a third driving transistor (T3) and a source electrode connected to a drain electrode of a second driving transistor (T2); a second driving transistor (T2) having a gate electrode connected to the other electrode of a capacitor element having one electrode connected to an input power supply (VDD), a drain electrode connected to the source electrode of the first driving transistor (T1), and a source electrode connected to ground; a third driving transistor (T3) having a drain electrode and a gate electrode connected to the input power supply (VDD), and a source electrode connected to the drain electrode and the source electrode of the first driving transistor (T); and a fourth driving transistor (T3) characterized in that a gate electrode is connected to the gate electrode of the second driving transistor (T2), a drain electrode is connected to the drain electrode of the first driving transistor (T1), and a source electrode is connected to ground;

[0015] Another feature is that it includes a reset transistor (Tr) whose drain electrode and gate electrode are connected to the input power supply (VDD) and whose source electrode is connected to the gate electrode of the second driving transistor (T2).

[0016] Preferably, the fifth driving transistor (T5) may further include a gate electrode connected to the drain electrode of the second driving transistor (T2), a source electrode connected to the gate electrode of the second driving transistor (T2), and a drain electrode connected to the input power supply (VDD).

[0017] Preferably, the first driving transistor (T1) to the fourth driving transistor (T4) and the reset transistor (Tr) may be n-channel MOSFETs, and the fifth driving transistor (T5) may be a p-channel MOSFET.

[0018] Preferably, the sixth driving transistor (T6) may further include a drain electrode connected to the gate electrode of the second driving transistor (T2), a gate electrode connected to the drain electrode of the second driving transistor (T2), and a source electrode connected to ground.

[0019] In order to achieve the above purpose, a touch sensing device according to another embodiment,

[0020] In a touch sensing device that stably maintains an output voltage level using a transistor,

[0021] A first driving transistor (T1) having a drain electrode and a gate electrode connected to an input power supply (VDD), and a source electrode connected to a drain electrode of a second driving transistor (T2); a second driving transistor (T2) having a gate electrode connected to the other electrode of a capacitive element, one electrode of which is connected to the input power supply (VDD), a drain electrode connected to the source electrode of the first driving transistor (T1), and a source electrode connected to ground; a touch electrode connected to the gate electrode of the second driving transistor (T2); an output terminal connected to the drain electrode of the second driving transistor (T2); And a reset transistor (Tr) having a drain electrode and a gate electrode connected to an input power supply (VDD) and a source electrode connected to a gate electrode of the second driving transistor (T2), so that when the touch electrode is not touched, the voltage of the output terminal becomes a voltage close to ground, when the touch electrode is touched, the voltage of the output terminal becomes a voltage close to the input power supply (VDD), and when the touch electrode is released, the voltage of the output terminal returns to the ground voltage.

[0022] The present invention has an advantage in that, when the node voltage of a part where a touch is made changes to a ground level due to a touch, the ground level can be stably maintained using a transistor.

[0023] In addition, the present invention has the advantage of stably maintaining the output at the ground level in a non-touch state by using a transistor.

[0024] In addition, the present invention has an advantage in that it can stably maintain the output at the input power level in a state where a touch is present by using a transistor.

[0025] The present invention has the advantage of being able to quickly restore the output to the ground level when the touch is released.

[0026] In addition, the present invention has the advantage of being noise-resistant by stabilizing the signal upon touch.

[0027] Figure 1 is a basic circuit diagram of a touch circuit according to an embodiment of the present invention.

[0028] FIG. 2 is a circuit diagram of a touch circuit according to another embodiment of the present invention.

[0029] FIG. 3 is a circuit diagram of a touch circuit with a transistor (T5) added to the circuit of FIG. 1 according to an embodiment of the present invention.

[0030] FIG. 4 is a circuit diagram of a touch circuit with transistors (T3, T4, T5) added to the circuit of FIG. 1 according to an embodiment of the present invention.

[0031] FIG. 5 is a circuit diagram of a touch circuit with a transistor (T6) added to the circuit of FIG. 1 according to an embodiment of the present invention.

[0032] Fig. 6 is a circuit diagram of a touch circuit with transistors (T5, T6) added to the circuit of Fig. 1. 1

[0033] Fig. 7 is a circuit diagram of a touch circuit with transistors (T3, T4, T5, T6) added to the circuit of Fig. 1.

[0034] Hereinafter, the present invention will be described in detail with reference to the contents described in the attached drawings. However, the present invention is not limited or restricted by the exemplary embodiments. The same reference numerals presented in each drawing indicate elements that perform substantially the same functions. While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms.

[0035] The present invention may be embodied in various other forms without departing from its technical spirit or essential characteristics. Therefore, the embodiments of the present invention are merely illustrative in all respects and should not be construed as limiting.

[0036] The above terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a second component, and similarly, a second component could also be referred to as a first component.

[0037] When it is said that a component is “connected” or “connected” to another component, it should be understood that it may be directly connected or connected to that other component, but there may also be other components in between.

[0038] On the other hand, when it is said that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

[0039] The terminology used in this application is solely for the purpose of describing specific embodiments and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0040] In this application, terms such as “include”, “have”, “have a branch”, etc. are intended to specify the presence of features, numbers, steps, operations, components, parts or combinations thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0041] Hereinafter, in order to explain in detail to an extent that a person having ordinary skill in the art to which the present invention pertains can easily practice the present invention, the most preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0042] Fig. 1 shows a basic circuit diagram of a touch circuit according to one embodiment of the present invention. As shown in Fig. 1, the touch circuit may include a first driving transistor (T1), a second driving transistor (T2), a capacitive element (C), and a reset transistor (Tr) to stably maintain an output voltage level using transistors. The first driving transistor (T1), the second driving transistor (T2), and the reset transistor (Tr) of the touch circuit may be implemented as an N-type metal-oxide-semiconductor field-effect transistor (MOSFET).

[0043] The first driving transistor (T1) of the embodiment of Fig. 1 may have a drain electrode and a gate electrode connected to an input power supply (VDD), and a source electrode connected to a drain electrode of a second driving transistor (T2). The second driving transistor (T2) may have a gate electrode connected to the other electrode of a capacitive element of which one electrode is connected to the input power supply (VDD), a drain electrode connected to the source electrode of the first driving transistor (T1), and a source electrode connected to ground.

[0044] According to the embodiment of FIG. 1, a touch circuit may include a capacitive element (C) disposed between an input power supply (VDD) and a second driving transistor (T2), a reset transistor (Tr) having a drain electrode and a gate electrode connected to the input power supply (VDD), and a source electrode connected to the gate electrode of the second driving transistor (T2).

[0045] Accordingly, the touch circuit can set the capacitance of the capacitive element (C) to be greater than the parasitic capacitance Cgs between the gate electrode and the source electrode of the second driving transistor (T2) so that the voltage (Vp) at point P when there is no touch can be close to the input power supply (VDD). Specifically, the voltage Vp at point P is determined by Vp=VDD*C / (Cgs+C), so that as C increases beyond Cgs, the voltage Vp at point P approaches VDD. At this time, the touch circuit can output (Vo) a low voltage approaching the ground voltage by turning on the first driving transistor (T1) and the second driving transistor (T2).

[0046] When a touch occurs, the touch circuit can increase the parasitic capacitance Cgs between the gate electrode and the source electrode of the second driving transistor (T2) to a greater extent than the capacitance of the capacitive element (C), so that the voltage (Vp) at point P can be brought close to the ground voltage. Accordingly, the touch circuit can output (Vo) a high voltage close to the input voltage (VDD) by maintaining the first driving transistor (T1) in an on state and turning the second driving transistor (T2) off.

[0047] In addition, when the touch is released, the touch circuit turns on the reset transistor (Tr), so that the voltage (Vp) at point P, which has been lowered by the touch, can quickly recover to a voltage close to the input voltage (VDD), and thus the output voltage can quickly recover to the ground voltage. In this way, the touch circuit can determine whether a touch is applied or released through the output voltage.

[0048] FIG. 2 is a circuit diagram of a touch circuit in which transistors (T3, T4) are added to the circuit of FIG. 1 to stably maintain an output at a ground level when a touch occurs according to one embodiment of the present invention. As illustrated in FIG. 2, the touch circuit may include a first driving transistor (T1), a second driving transistor (T2), a third driving transistor (T3), a fourth driving transistor (T4), a capacitor (C), and a reset transistor (Tr) to stably maintain an output voltage level using transistors. The first to fourth driving transistors (T1) to (T4) and the reset transistor (Tr) of the touch circuit may be implemented as N-type MOSFETs.

[0049] According to the embodiment of Fig. 2, the first driving transistor (T1) may have a drain electrode and a gate electrode connected to the source electrode of the third driving transistor (T3), and a source electrode connected to the drain electrode of the second driving transistor (T2). The second driving transistor (T2) may have a gate electrode connected to the other electrode of a capacitor element of which one electrode is connected to the input voltage (VDD), a drain electrode connected to the source electrode of the first driving transistor (T1), and a source electrode connected to ground.

[0050] The third driving transistor (T3) may have its drain electrode and gate electrode connected to the input voltage (VDD), and its source electrode connected to the drain electrode and source electrode of the first driving transistor (T). The fourth driving transistor (T4) may have its gate electrode connected to the gate electrode of the second driving transistor (T2), its drain electrode connected to the drain electrode of the first driving transistor (T1), and its source electrode connected to ground.

[0051] And the reset transistor (Tr) may have a drain electrode and a gate electrode connected to the input power supply (VDD), and a source electrode connected to the gate electrode of the second driving transistor (T2).

[0052] In the touch circuit according to the embodiment of Fig. 2, when there is no touch, the voltage (Vp) at point P becomes the input power (VDD), so that the input power (VDD) is applied to the gate electrode of the fourth driving transistor (T4) to turn on the fourth driving transistor (T4). Accordingly, the touch circuit can lower the voltage of the gate electrode of the first driving transistor (T1) connected to the drain electrode of the fourth driving transistor (T4) and the train electrode of the first driving transistor (T1) to the ground voltage. Therefore, the touch circuit can more stably maintain the output voltage (Vo) at the ground potential level.

[0053] FIG. 3 is a circuit diagram of a touch sensor circuit according to an embodiment of the present invention, in which a transistor (T5) is added to the circuit of FIG. 1 to stably maintain the node voltage of a portion where a touch is made at an input power level when there is no touch. As illustrated in FIG. 3, the touch circuit may include a first driving transistor (T1), a second driving transistor (T2), a fifth driving transistor (T5), a capacitive element (C), and a reset transistor (Tr) to stably maintain an output voltage level using transistors. In the touch circuit, the first driving transistor (T1), the second driving transistor (T2), and the reset transistor (Tr) may be implemented as N-type MOSFETs, and the fifth driving transistor (T5) may be implemented as P-type MOSFETs.

[0054] The first driving transistor (T1) and the second driving transistor (T2) according to the embodiment of FIG. 3 have the same connection relationship as FIG. 1, and the fifth driving transistor (T5) has a gate electrode connected to the drain electrode of the second driving transistor (T2), a source electrode connected to the gate electrode of the second driving transistor (T2), and a drain electrode connected to the input voltage (VDD).

[0055] In the touch circuit according to the embodiment of Fig. 3, when there is no touch, the voltage (Vp) at point P becomes the input power supply (VDD), so the second driving transistor (T2) is turned on. Accordingly, the touch circuit applies a ground voltage to the gate electrode of the fifth driving transistor (T5) connected to the drain electrode (output terminal) of the second driving transistor (T2), so the fifth driving transistor (T5) is turned on. Accordingly, the touch circuit can more stably maintain the voltage (Vp) at point P at the level of the input voltage (VDD). When a touch occurs, the input voltage (VDD) is applied to the gate electrode of the fifth driving transistor (T5), so the fifth driving transistor (T5) is turned off, and the voltage (Vp) at point P is not affected.

[0056] FIG. 4 is a circuit diagram of a touch sensor circuit in which transistors (T3, T4, T5) are added to the circuit of FIG. 1 so as to have all the advantages shown in FIGS. 2 and 3 according to an embodiment of the present invention. As illustrated in FIG. 4, the touch circuit may include first to fifth driving transistors (T1) to (T5), a capacitive element (C), and a reset transistor (Tr) to stably maintain an output voltage level using transistors. In the touch circuit, the first to fourth driving transistors (T1) to (T2) and the reset transistor (Tr) may be implemented as N-type MOSFETs, and the fifth driving transistor (T5) may be implemented as P-type MOSFETs.

[0057] The first driving transistor (T1) to the fourth driving transistor (T4) and the reset transistor (Tr) according to the embodiment of Fig. 4 have the same connection relationship as in Fig. 2, and the fifth driving transistor (T5) has the same connection relationship as in Fig. 3.

[0058] According to the embodiment of Fig. 4, the touch circuit can stabilize the output voltage (Vo) to the ground voltage level by the fourth driving transistor (T4) when there is no touch (the principle is the same as Fig. 2). In addition, the touch circuit can stabilize the voltage (Vp) of point P to the input voltage (VDD) level by turning on the fifth driving transistor (T5) (the principle is the same as Fig. 3).

[0059] FIG. 5 is a circuit diagram of a touch sensor circuit in which a transistor (T6) is added to the circuit of FIG. 1 to stably maintain the node voltage of a portion where a touch occurs at a ground level when a touch occurs according to an embodiment of the present invention. As illustrated in FIG. 5, the touch circuit may include a first driving transistor (T1), a second driving transistor (T2), a sixth driving transistor (T6), a capacitive element (C), and a reset transistor (Tr) to stably maintain an output voltage level using transistors. The touch circuit may be implemented with an N-type MOSFET for the first driving transistor (T1), the second driving transistor (T2), the sixth driving transistor (T6), and the reset transistor (Tr).

[0060] The first driving transistor (T1) and the second driving transistor (T2) according to the embodiment of FIG. 5 have the same connection relationship as FIG. 1, and the sixth driving transistor (T6) may have a drain electrode connected to the gate electrode of the second driving transistor (T2), a gate electrode connected to the drain electrode of the second driving transistor (T2), and a source electrode connected to ground.

[0061] In another embodiment of the touch circuit of FIG. 5, when there is no touch, the voltage (Vp) at point P becomes the input power supply (VDD) and the output voltage (Vo) becomes the ground voltage, so the ground voltage is applied to the gate electrode of the sixth driving transistor (T6) connected to the drain electrode (output terminal) of the second driving transistor (T2). Therefore, the touch circuit does not affect the voltage (Vp) at point P because the sixth driving transistor (T6) is turned off.

[0062] When a touch occurs, the voltage (Vp) at point P decreases, and the output voltage (Vo) becomes close to the input voltage (VDD), so that the input voltage (VDD) is applied to the gate electrode of the sixth driving transistor (T6). Accordingly, the touch circuit can stabilize the voltage (Vp) at point P to the ground voltage level by turning on the sixth driving transistor (T6).

[0063] In addition, when the touch circuit is released, the reset transistor (Tr) is turned on, and the voltage (Vp) of point P, which has been lowered by the touch, is quickly restored to a voltage close to the input voltage (VDD).

[0064] Fig. 6 is a circuit diagram of a touch sensor circuit in which transistors (T5, T6) are added to the circuit of Fig. 1 so as to have all the advantages shown in Figs. 3 and 5 according to an embodiment of the present invention. As shown in Fig. 6, the touch circuit may include a first driving transistor (T1), a second driving transistor (T2), a fifth driving transistor (T5), a sixth driving transistor (T6), a capacitor element (C), and a reset transistor (Tr). The first driving transistor (T1), the second driving transistor (T2), the sixth driving transistor (T6), and the reset transistor (Tr) of the touch circuit may be implemented as N-type MOSFETs, and the fifth driving transistor (T5) may be implemented as P-type MOSFETs.

[0065] The first driving transistor (T1), the second driving transistor (T4), the sixth driving transistor (T6), and the reset transistor (Tr) according to the embodiment of FIG. 6 have the same connection relationship as in FIG. 5, and the fifth driving transistor (T5) has the same connection relationship as in FIG. 3.

[0066] The touch circuit according to the embodiment of Fig. 6 can more stably maintain the voltage (Vp) of point P at the level of the input voltage (VDD) by turning on the fifth driving transistor (T5) when there is no touch. At this time, the sixth driving transistor (T6) remains in the off state. When a touch occurs, the touch circuit can stabilize the voltage (Vp) of point P at the level of the ground voltage by turning on the sixth driving transistor (T6).

[0067] When the touch circuit is released, the reset transistor (Tr) is turned on so that the voltage (Vp) at point P, which has been lowered by the touch, can quickly recover to a voltage close to the input voltage (VDD).

[0068] Fig. 7 is a circuit diagram of a touch sensor circuit having transistors (T3, T4, T5, T6) added thereto so as to have all the advantages shown in Figs. 1 to 6 according to an embodiment of the present invention. As shown in Fig. 7, the touch circuit may include first to sixth driving transistors (T1) to (T6), a capacitive element (C), and a reset transistor (Tr). The first to fourth driving transistors (T1) to (T4), the sixth driving transistor (T6), and the reset transistor (Tr) may be implemented as N-type MOSFETs, and the fifth driving transistor (T5) may be implemented as P-type MOSFETs.

[0069] The first driving transistor (T1) to the fifth driving transistor (T5) and the reset transistor (Tr) according to the embodiment of Fig. 7 have the same connection relationship as in Fig. 4, and the sixth driving transistor (T6) has the same connection relationship as in Fig. 5.

[0070] The touch circuit according to the embodiment of Fig. 7 can more stably maintain the voltage (Vp) of point P at the level of the input voltage (VDD) by turning on the fifth driving transistor (T5) and turning off the sixth driving transistor (T6) when there is no touch. In addition, since the touch circuit turns on the fourth driving transistor (T4) when there is no touch, the voltage of point a is lowered to the ground voltage, so that the output voltage (Vo) can be stabilized at the level of the ground voltage.

[0071] When a touch occurs, the touch circuit turns off the fourth driving transistor (T4) and the output voltage (Vo) increases. Accordingly, the fifth driving transistor (T5) turns off and the sixth driving transistor (T6) turns on, so that the voltage (Vp) at point P can be stabilized at the ground voltage level.

[0072] And when the touch circuit is released, the reset transistor (Tr) is turned on so that the voltage (Vp) of point P, which has been lowered by the touch, can be quickly recovered to a voltage close to the input voltage (VDD), and thus the output voltage (Vo) can be quickly recovered to the ground voltage level.

[0073] Another embodiment of the present invention is a touch sensing device, which is composed of the touch circuit described above, and may further include a touch electrode connected to the gate electrode of the second driving transistor (T2) and an output terminal connected to the drain electrode of the second driving transistor (T2). When the touch electrode is not touched, the voltage of the output terminal may be a voltage close to the ground, and when the touch electrode is touched, the voltage of the output terminal may be a voltage close to the input voltage (VDD). All of the embodiments of FIGS. 1 to 6 can be applied to the touch circuit of the touch sensing device.

[0074] While the present invention has been described in detail through representative examples above, those skilled in the art will understand that various modifications to the above-described embodiments are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims described below but also by all changes or modifications derived from the claims and equivalent concepts.

Claims

1. In a touch circuit that stably maintains an output voltage level using a transistor, A first driving transistor (T1) having a drain electrode and a gate electrode connected to an input power supply (VDD) and a source electrode connected to a drain electrode of a second driving transistor (T2); and A second driving transistor (T2) having a gate electrode connected to the other electrode of a capacitor element connected to an input power supply (VDD), a drain electrode connected to the source electrode of the first driving transistor (T1), and a source electrode connected to ground; A touch circuit characterized by further including a reset transistor (Tr) having a drain electrode and a gate electrode connected to an input power supply (VDD) and a source electrode connected to the gate electrode of the second driving transistor (T2).

2. In a touch circuit that maintains a stable output voltage level using a transistor, A first driving transistor (T1) having a drain electrode and a gate electrode connected to the source electrode of a third driving transistor (T3) below, and a source electrode connected to the drain electrode of a second driving transistor (T2) below; A second driving transistor (T2) having a gate electrode connected to the other electrode of a capacitor element, one electrode of which is connected to an input power supply (VDD), a drain electrode connected to the source electrode of the first driving transistor (T1), and a source electrode connected to ground; A third driving transistor (T3) having a drain electrode and a gate electrode connected to an input power supply (VDD) and a source electrode connected to the drain electrode and the source electrode of the first driving transistor (T); and A fourth driving transistor (T3) characterized in that a gate electrode is connected to the gate electrode of the second driving transistor (T2), a drain electrode is connected to the drain electrode of the first driving transistor (T1), and a source electrode is connected to ground; A touch circuit characterized by further including a reset transistor (Tr) having a drain electrode and a gate electrode connected to an input power supply (VDD) and a source electrode connected to the gate electrode of the second driving transistor (T2).

3. In paragraph 1 or 2, A touch circuit characterized by further comprising a fifth driving transistor (T5) having a gate electrode connected to the drain electrode of the second driving transistor (T2), a source electrode connected to the gate electrode of the second driving transistor (T2), and a drain electrode connected to an input power supply (VDD).

4. In paragraph 3, A touch circuit, characterized in that the first to fourth driving transistors (T1) and the reset transistor (Tr) are N-type MOSFETs, and the fifth driving transistor (T5) is a P-type MOSFET.

5. In paragraph 1 or 2, A touch circuit characterized by further comprising a sixth driving transistor (T6) having a drain electrode connected to the gate electrode of the second driving transistor (T2), a gate electrode connected to the drain electrode of the second driving transistor (T2), and a source electrode connected to ground.

6. In a touch sensing device that stably maintains an output voltage level using a transistor, A first driving transistor (T1) having a drain electrode and a gate electrode connected to an input power supply (VDD), and a source electrode connected to a drain electrode of a second driving transistor (T2); A second driving transistor (T2) having a gate electrode connected to the other electrode of a capacitor element connected to an input power supply (VDD), a drain electrode connected to the source electrode of the first driving transistor (T1), and a source electrode connected to ground; A touch electrode connected to the gate electrode of the second driving transistor (T2); and An output terminal connected to the drain electrode of the second driving transistor (T2); It further includes a reset transistor having a drain electrode and a gate electrode connected to the input power supply (VDD) and a source electrode connected to the gate electrode of the second driving transistor (T2). A touch sensing device characterized in that when the touch electrode is not touched, the voltage of the output terminal becomes a voltage close to ground, when the touch electrode is touched, the voltage of the output terminal becomes a voltage close to the input power supply (VDD), and when the touch is released, the voltage of the output terminal returns to a voltage close to ground.

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