CN104102384B - Touch detection circuit - Google Patents

Abstract

A touch detection circuit is provided. The touch detection circuit comprises a touch unit, a comparison unit and a touch result generation unit. The touch unit provides a detection signal according to the touched state. The comparison unit is coupled with the touch unit and provides a reference current. The comparison unit generates a touch state current according to a voltage difference between the detection signal and the first reference voltage, and compares the reference current and the touch state current to generate a comparison voltage. The touch result generating unit is coupled to the comparator and provides a touch result signal according to the comparison voltage. The touch detection circuit of the invention can obtain the current touch state of the touch panel and the position of the touch point on the touch panel by analyzing the touch result signal.

Description

touch detection circuit

technical field

The present invention relates to a touch circuit, and in particular to a touch detection circuit.

Background technique

With the development and progress of science and technology, the user interface of electronic products has gradually evolved from traditional keys, keyboards or mice to a more humanized touch interface. For example, the user can use a finger or a stylus to perform touch operations on the light-sensitive touch panel. On the other hand, a light detection circuit is often used in the touch panel to sense the current touch position of the user. For example, FIG. 1 shows a schematic diagram of a light detection circuit 100 . The light detection circuit 100 can be applied to a light-sensitive touch panel to detect the position of a touch point on the touch panel.

The light detection circuit 100 includes a transistor Q, a capacitor C and a light detection transistor P. As shown in FIG. The scan line SCAN1 of the touch panel can be used to control the switching state of the transistor Q. The photodetecting transistor P generates different currents Id under different intensities of light. One end of the capacitor C is coupled to the transistor Q, and the other end is coupled to the power supply VDD. The capacitor C is used to store the charge generated by the current Id. When the transistor Q is turned on, the charge stored in the capacitor C will be transferred to the data line DATA1 of the touch panel through the transistor Q. Since the current Id is different, the amount of charge in the capacitor C will also be different. Therefore, the light detection circuit 100 can determine the current touch condition of the touch panel according to the amount of charge received by the data line DATA1.

However, when the intensity of light detected by the photodetecting transistor P is insufficient or the photosensitive time is not long enough, the charge stored in the capacitor C is too small, which will cause the voltage of the terminal VA to be insufficient, and the touch panel cannot judge the touch. point position. On the other hand, the voltage difference between the gate G and the source S of the photodetection transistor P (i.e., Vgs) is usually operated under a negative bias voltage to control the current Id, but this is easy to cause deterioration of the photodetection transistor P situation.

Contents of the invention

The invention provides a touch detection circuit, which improves the light sensitivity of the touch panel by increasing the light sensing speed of the touch detection circuit.

The touch detection circuit of the present invention includes a touch unit, a comparison unit and a touch result generation unit. The touch unit provides a detection signal according to a touched state. The comparison unit is coupled to the touch control unit and provides a reference current. The comparison unit generates a touch state current according to the voltage difference between the detection signal and the first reference voltage. The comparison unit compares the reference current and the touch state current to generate a comparison voltage. The touch result generating unit is coupled to the comparator and provides a touch result signal according to the comparison voltage.

Based on the above, the comparison unit in the touch detection circuit of the present invention generates a comparison voltage by comparing the voltage difference between the detection signal provided by the touch unit in different touch states and the first reference voltage. Then, the touch result generating unit provides a touch result signal according to the comparison voltage. In this way, the touch detection circuit of the present invention can obtain the current touch state of the touch panel and the position of the touch point on the touch panel by analyzing the touch result signal.

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

Description of drawings

FIG. 1 is a schematic diagram of a light detection circuit 100 .

2 to 3A, and FIGS. 4 to 8 respectively illustrate schematic diagrams of touch detection circuits according to multiple embodiments of the present invention.

FIG. 3B is a schematic diagram of readout waveforms of the touch detection circuit 300 in FIG. 3A .

Among them, reference signs

100: Light detection circuit

200, 300, 400, 500, 600, 700, 800: touch detection circuit

202, 302, 402, 502, 602, 702, 802: touch unit

204, 304, 404, 504, 604, 704, 804: comparison unit

206, 306, 406, 506, 606, 706, 806: touch result generation unit

A, B: curve

C, CT, CR: capacitance

DATA1, DATA3: data line

D1～D3: Diodes

F: Waveform period

G: gate

Id: current

IREF1: reference current

IT1, IT2: touch state current

P, P1～P7: photodetection transistor

S: source

SCAN1, SCAN3: scan lines

SD1～SD6: detection signal

ST1, ST2: touch result signal

VA, VA1～VA3: endpoints

VCOMP, VCOMP1, VCOMP2: comparison voltage

VREF1, VC2, VC4, T1, T2: Reference voltage

VC1, VC3: reference voltage source

VC5: Reference power supply

VDD: power supply

Q, M1~M6, MA, MB1~MB4, MC1~MC2, MD1~MD4, MF,

MN: Transistor

detailed description

The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments to further understand the purpose, solution and effect of the present invention, but it is not intended to limit the scope of protection of the appended claims of the present invention.

FIG. 2 is a schematic diagram of a touch detection circuit 200 according to an embodiment of the present invention. The touch detection circuit 200 includes a touch unit 202 , a comparison unit 204 and a touch result generation unit 206 . The touch detection circuit 200 can be applied in a photosensitive touch panel to detect the position of a touch point on the touch panel. The touch unit 202 provides a detection signal SD1 according to a touched state. The touch control unit 202 may include a photo sensor (Photo Sensor), a light detection thin film transistor (Thin Film Transistor, TFT), or other electronic components with a light detection function. The light intensity felt by the touch unit 202 is different depending on whether the touch unit 202 is touched. In different touch states, the touch unit 202 generates different detection signals SD1. Wherein, the detection signal SD1 is a voltage signal.

On the other hand, the comparing unit 204 can be composed of TFT or other electronic circuits with comparator function. The comparison unit 204 is coupled to the touch control unit 202 to receive the detection signal SD1, and compares the voltage difference between the detection signal SD1 and the reference voltage VREF1 to generate different touch state currents. Next, the comparison unit 204 compares the touch state current with the reference current, and then generates a comparison voltage VCOMP. It should be noted that the current value of the reference current can be preset as a comparison reference.

The touch result generation unit 206 is coupled to the comparison unit 204 , and the touch result generation unit 206 provides a touch result signal ST1 according to the comparison voltage VCOMP after receiving the comparison voltage VCOMP. For example, when the touch unit 202 is touched by the user's finger, the light received by the touch unit 202 will be reduced due to being shielded by the user's finger, and the voltage of the detection signal SD1 will be lower than the voltage of the reference voltage VREF1 . The comparison unit 204 calculates the voltage difference between the detection signal SD1 and the reference voltage VREF1 to generate a comparison voltage VCOMP, and transmits the comparison voltage VCOMP to the touch result generation unit 206 . The touch result generating unit 206 can amplify the comparison voltage VCOMP and provide a corresponding touch result signal ST1. In this way, the touch detection circuit 200 can know that the touch unit 202 is currently in a touched state through the touch result signal ST1.

Similarly, when the touch unit 202 is not touched, the touch unit 202 can receive more light because it is not covered by objects, and the voltage of the detection signal SD1 will be greater than the voltage of the reference voltage VREF1 . In this way, the touch detection circuit 200 can obtain a different touch result signal ST1 through the comparison voltage VCOMP different from the above example, and know that the touch unit 202 is not currently touched by the different touch result signal ST1. touched by the user's finger.

It is worth mentioning that the above reference current can be set between the first current and the second current. The first current is the touch state current corresponding to the comparison unit 204 when the touch unit 202 is touched, and the second current is the touch current corresponding to the comparison unit 204 when the touch unit 202 is not touched. control state current. For example, the current value of the reference current may be equal to the current value of the touch state current correspondingly generated by the comparison unit 204 when the voltage difference between the detection signal SD1 and the reference voltage VREF1 is equal to 0.

FIG. 3A is a schematic diagram of a touch detection circuit 300 according to another embodiment of the present invention. The touch detection circuit 300 includes a touch unit 302 , a comparison unit 304 and a touch result generation unit 306 . The touch unit 302 includes a diode D1 and a light detection transistor P1. The anode of the diode D1 is coupled to the reference voltage source VC1, and the cathode of the diode D1 provides the detection signal SD2. In this embodiment, the photodetection transistor P1 is an N-type TFT, and the photodetection transistor P1 has a first terminal (such as a drain), a second terminal (such as a source) and a control terminal (such as a gate). The first terminal of the photodetection transistor P1 is coupled to the cathode of the diode D1, and the second terminal and the control terminal of the photodetection transistor P1 are mutually coupled to the reference voltage VC2. From another point of view, when the diode D1 is turned on, it can provide a fixed resistance value, while the light detection transistor P1 has a variable resistance value according to the detected light intensity. Therefore, the touch control unit 302 can be regarded as a voltage divider circuit, wherein the diode D1 and the photodetection transistor P1 divide the voltage of the reference voltage source VC1 and the reference voltage VC2 to generate the detection signal SD2.

The comparing unit 304 includes a diode D2 and a transistor M1. The anode of the diode D2 is coupled to the reference voltage source VC3, and the cathode of the diode D2 generates the comparison voltage VCOMP1. Diode D2 is used to generate reference current IREF1. In this embodiment, the transistor M1 is an N-type TFT, and the transistor M1 has a first terminal (such as a drain), a second terminal (such as a source) and a control terminal (such as a gate). The first terminal of the transistor M1 is coupled to the cathode of the diode D2, the control terminal of the transistor M1 is used to receive the detection signal SD2, and the second terminal of the transistor M1 is coupled to the reference voltage VC4. Assuming that the detection signal SD2 is a voltage signal, the transistor M1 generates the touch state current IT1 according to the voltage difference between the detection signal SD2 and the reference voltage VC4 .

For example, when the user's finger touches the touch unit 302 , the light received by the light detection transistor P1 will be less than when the user's finger does not touch the touch unit 302 . Therefore, under different touch states of the touch unit 302 , the leakage current generated by the photodetection transistor P1 will also be different. In other words, the detection signal SD2 provided by the cathode terminal of the diode D1 will also be different. Therefore, for the transistor M1, under different touch states of the touch unit 302, the voltage difference (Vgs) generated between the control terminal and the second terminal will also be different, and the touch generated by the transistor M1 will be different. The control state current IT1 is different. In this embodiment, the reference current IREF1 provided by the diode D2 can be regarded as a fixed reference current. The comparison unit 304 compares the current IT1 in different touch states with the reference current IREF1 , and generates a comparison voltage VCOMP1 according to the comparison result. Please refer to the following for details.

The touch result generating unit 306 includes a transistor MA and a transistor MN. In this embodiment, the transistor MA and the transistor MN are N-type TFTs. The transistor MA has a first terminal (such as a drain), a second terminal (such as a source) and a control terminal (such as a gate). The first terminal of the transistor MA receives the reference power VC5 , and the control terminal of the transistor MA is coupled to the comparison voltage VCOMP1 . The transistor MN has a first terminal (such as a drain), a second terminal (such as a source) and a control terminal (such as a gate). The first terminal of the transistor MN is coupled to the second terminal of the transistor MA, the control terminal of the transistor MN is coupled to the scan line SCAN3 , and the second terminal of the transistor MN generates a touch result signal ST2 and transmits it to the coupled data line DATA3 .

FIG. 3B is a schematic diagram of readout waveforms of the touch detection circuit 300 in FIG. 3A . Wherein, the horizontal axis of FIG. 3B represents time, and the unit may be microsecond (μs), the vertical axis represents voltage, and the unit may be millivolt (mV), and F represents the waveform period. Please refer to FIG. 3A and FIG. 3B at the same time. Curve A represents the voltage change of the drain of the transistor M1 when the touch unit 302 does not detect any light change. On the other hand, the curve B represents the change of the drain voltage of the transistor M1 when the touch unit 302 detects the light change. From the curve B, it can be seen that when the touch unit 302 detects a light change, the drain voltage of the transistor M1 only needs 0.01 F to reach the comparison voltage VCOMP1. From another point of view, the touch detection circuit 300 can reduce the light-sensing time of the light-detecting transistor P1 to increase the sensing speed.

The action relationship between the comparing unit 304 and the touch result generating unit 306 will be described in detail below. The comparison voltage VCOMP1 generated by the comparison unit 304 is transmitted to the gate of the transistor MA. Here, the transistor MA can be used as an amplifier to amplify according to the reference power VC5 and the comparison voltage VCOMP1 received by the control terminal. The amplified signal is transmitted to the transistor MN, and when the transistor MN is turned on, the amplified signal is transmitted to the data line DATA3 through the transistor MN to generate the touch result signal ST2.

FIG. 4 is a schematic diagram of a touch detection circuit 400 according to yet another embodiment of the present invention. The touch detection circuit 400 includes a touch unit 402 , a comparison unit 404 and a touch result generation unit 406 . The touch unit 402 includes a transistor MD1 and a light detecting transistor P2. In this embodiment, the transistor MD1 is an N-type TFT, and the transistor MD1 has a first terminal (such as a drain), a second terminal (such as a source) and a control terminal (such as a gate). The first terminal of the transistor MD1 is coupled to the reference voltage source VC1, and the second terminal and the control terminal of the transistor MD1 are commonly coupled to provide a detection signal SD3. The comparing unit 404 includes a transistor MB1 and a transistor M2. In this embodiment, the transistor MB1 and the transistor M2 are N-type TFTs, and the transistor MB1 has a first terminal (such as a drain), a second terminal (such as a source) and a control terminal (such as a gate). The first terminal of the transistor MB1 receives the reference voltage source VC3 , and the control terminal and the second terminal of the transistor MB1 are commonly coupled to the first terminal of the transistor M2 . From another point of view, the diode D1 in FIG. 3A can be regarded as the transistor MD1 in FIG. 4 , and the diode D2 can be regarded as the transistor MB1. On the other hand, please refer to FIG. 3A for the coupling relationship of the photodetecting transistor P2 , the transistor M2 , the reference voltage VC2 , the reference voltage VC4 , and the touch result generating unit 406 , and will not be repeated here.

The operation of the touch detection circuit 400 will be described below, please also refer to FIG. 3 . The transistor MD1 and the photodetection transistor P2 divide the voltage of the reference voltage source VC1 and the reference voltage VC2 to generate the detection signal SD3. On the other hand, since the control terminal and the second terminal of the transistor MB1 are coupled to each other, the voltage difference between the control terminal and the second terminal of the transistor MB1 is zero. The comparison unit 404 compares the voltage difference between the control terminal and the second terminal of the transistor MB1 (which is zero) with the voltage difference between the control terminal and the second terminal of the transistor M2 (the voltage difference between the detection signal SD3 and the reference voltage VC4 ). When the voltage difference between the detection signal SD3 and the reference voltage VC4 is greater than zero (for example, the touch unit 402 is touched by a finger), the voltage of the terminal VA1 approaches the reference voltage VC4 . On the other hand, when the voltage difference between the control terminal and the second terminal of the transistor M2 is less than zero (for example, the touch unit 402 is not touched by a finger), the voltage of the terminal VA1 approaches the reference voltage source VC3 . In this way, under different touch conditions of the touch unit 402 , the voltage of the terminal VA1 will be significantly different.

FIG. 5 is a schematic diagram of a touch detection circuit 500 according to another embodiment of the present invention. The touch detection circuit 500 includes a touch unit 502 , a comparison unit 504 and a touch result generation unit 506 . The touch unit 502 includes a transistor MD2 and a light detection transistor P3. The comparison unit 504 includes a transistor MB2 and a transistor M3. For the operation of the touch result generating unit 506 , please refer to the touch result generating unit 306 . Please refer to FIG. 4 and FIG. 5 at the same time. The difference between the touch detection circuit 400 and the touch detection circuit 500 is that the control terminal and the second terminal of the transistor M3 receive the reference voltage VC4 and the detection signal SD4 respectively. However, the coupling relationship of the transistor M2 is opposite to that of the transistor M3, and the control terminal and the second terminal of the transistor M2 respectively receive the detection signal SD3 and the reference voltage VC4.

FIG. 6 is a schematic diagram of a touch detection circuit 600 according to another embodiment of the present invention. The touch detection circuit 600 includes a touch unit 602 , a comparison unit 604 and a touch result generation unit 606 . The touch control unit 602 includes a transistor MD3 , a transistor MC1 , a photodetection transistor P4 and a photodetection transistor P5 . The comparison unit 604 includes a transistor MB3 and a transistor M4. Please refer to FIG. 4 to FIG. 6 at the same time. Compared with the touch unit 402 and the touch unit 502 , the touch unit 602 has a light detection transistor P5 and a transistor MC1 added in the touch unit 602 . The photodetecting transistor P5 and the transistor MC1 divide the voltage difference between the reference voltage source VC1 and the reference voltage VC4 to generate the reference voltage T1 . The control terminal of the transistor M4 receives the detection signal SD5, and the second terminal of the transistor M4 receives the reference voltage T1.

In another embodiment, the transistor MD3 can be replaced by a diode, the anode of the diode is coupled to the reference voltage source VC1 , and the cathode of the diode is used to provide the detection signal SD5. On the other hand, the transistor MC1 can also be replaced by a diode, the anode of the diode is coupled to the reference voltage source VC1 , and the cathode of the diode is used to provide the reference voltage T1 . In the embodiment of FIG. 6 , when the light intensity received by the photodetection transistor P4 and the photodetection transistor P5 changes, the detection signal SD5 and the reference voltage T1 also change accordingly. On the other hand, please refer to FIG. 4 to FIG. 6 , the second terminal of the transistor M2 in FIG. 4 and the control terminal of the transistor M3 in FIG. 5 are both coupled to the reference voltage VC4 (which can be regarded as a fixed voltage). However, the voltage difference between the control terminal (receives the detection signal SD5) and the second terminal (receives the reference voltage T1) of the transistor M4 will change greatly with the light intensity, thereby improving the touch detection efficiency. sensitivity.

FIG. 7 is a schematic diagram of a touch detection circuit 700 according to another embodiment of the present invention. The touch detection circuit 700 includes a touch unit 702 , a comparison unit 704 and a touch result generation unit 706 . The touch unit 702 includes a transistor MD4 , a transistor MC2 , a photodetector transistor P6 and a photodetector transistor P7 . The comparison unit 704 includes a transistor MF, a transistor MB4 and a transistor M5. In this embodiment, the transistor MF, the transistor MB4 and the transistor M5 are N-type TFTs. The transistor MF has a first terminal (such as a drain), a second terminal (such as a source) and a control terminal (such as a gate). A first terminal of the transistor MF is coupled to a reference voltage source VC3, and a second terminal of the transistor MF generates a comparison voltage VCMOP2. The first terminal of the transistor MB4 is coupled to the second terminal of the transistor MF, and the second terminal of the transistor MB4 and the control terminal are jointly coupled to the control terminal of the transistor MF. In another embodiment, the transistor MB4 can be replaced by a diode, the anode of the diode is coupled to the second terminal of the transistor MF, and the cathode of the diode is coupled to the control terminal of the transistor MF. A diode can be used to generate a reference current.

The transistor M5 has a first terminal (such as a drain), a second terminal (such as a source) and a control terminal (such as a gate). The first terminal of the transistor M5 is coupled to the second terminal of the transistor MB4, the control terminal of the transistor M5 receives the detection signal SD6, and the second terminal of the transistor M5 is coupled to the reference voltage T2. The transistor MF generates the touch state current IT2 according to the voltage difference between the detection signal SD6 and the reference voltage T2 . Please refer to FIG. 6 and FIG. 7 at the same time. It is worth noting that, comparing the comparison unit 704 with the comparison unit 604 , a transistor MF is added in the comparison unit 704 . The transistor MF can limit the magnitude of the current flowing to the transistor MC2 and the light detection transistor P7, and can limit the operating current consumed by the touch detection circuit 700 .

FIG. 8 is a schematic diagram of a touch detection circuit 800 according to another embodiment of the present invention. The touch detection circuit 800 is applicable to a capacitive touch panel. The touch detection circuit 800 includes a touch unit 802 , a comparison unit 804 and a touch result generation unit 806 . The touch unit 802 includes a touch detection capacitor CT and a reference capacitor CR. The first end of the touch detection capacitor CT receives the detection signal SD7, and the second end of the touch detection capacitor CT is used to provide the detection signal SD7. The reference capacitor CR is connected in series between the second terminal of the touch detection capacitor CT and the reference ground terminal GND. The touch result generating unit 806 may be an analog-to-digital converter. In this embodiment, the touch result generating unit 806 can know the touch condition of the touch panel according to the voltage change of the terminal VA3 .

To sum up, the touch detection circuit of the present invention utilizes the touch unit to provide different detection signals according to different touch states of the touch panel. Then, after receiving the detection signal, the comparison unit compares the detection signal with the reference voltage to generate a comparison voltage. Finally, the touch result generating unit amplifies the signal of the comparison voltage and provides a touch result signal. In this way, the touch detection circuit of the present invention can know the touch condition of the touch panel according to the touch result signal. In other words, the touch detection circuit of the present invention judges the current touch situation of the touch panel by analyzing the voltage difference generated by the touch panel under different touch states, so as to improve the detection sensitivity. Therefore, the touch detection circuit of the present invention can save the illumination time required by the light detection transistor, so as to increase the detection speed and sensitivity.

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding Changes and deformations should all belong to the protection scope of the appended claims of the present invention.

Claims (11)

1. A touch detection circuit, characterized in that, comprising: A touch unit, which provides a detection signal according to the touched state; A comparison unit, coupled to the touch unit, provides a reference current, the comparison unit generates a touch state current according to the voltage difference between the detection signal and a first reference voltage, and the comparison unit compares the reference current and the first reference voltage the touch state current to generate a comparison voltage; and a touch result generating unit coupled to the comparison unit to provide a touch result signal according to the comparison voltage; Among them, the comparison unit includes: a diode, its anode is coupled to a reference voltage source, its cathode generates the comparison voltage, and the diode is used to generate the reference current; and A first transistor has a first terminal, a second terminal and a control terminal, the first terminal of the first transistor is coupled to the cathode of the diode, one of the second terminal and the control terminal of the first transistor receives the detection detection signal, and the other one of the second terminal and the control terminal of the first transistor is coupled to the first reference voltage, and the first transistor generates the touch control according to the voltage difference between the detection signal and the first reference voltage state current. 2. The touch detection circuit according to claim 1, wherein the touch unit comprises: a diode, its anode is coupled to a reference voltage source, and its cathode provides the detection signal; and A photodetection transistor has a first terminal, a second terminal and a control terminal, the first terminal of which is coupled to the cathode of the diode of the touch unit, and the second terminal and the control terminal of the photodetection transistor are mutually coupled to a second reference voltage. 3. The touch detection circuit according to claim 2, wherein the diode of the touch unit is a transistor having a first terminal, a second terminal and a control terminal, and the first terminal of the transistor is coupled to the The reference voltage source, the second terminal of the transistor and the control terminal are commonly coupled to provide the detection signal. 4. The touch detection circuit according to claim 2, wherein the light detection transistor and the diode are used to divide the voltage difference between the reference voltage source and the second reference voltage to generate the detection voltage. test signal. 5. The touch detection circuit according to claim 1, wherein the diode is a second transistor having a first terminal, a second terminal and a control terminal, and the first terminal of the second transistor receives the reference The voltage source, the control terminal and the second terminal of the second transistor are jointly coupled to the first terminal of the first transistor. 6. The touch detection circuit according to claim 1, wherein the touch unit comprises: a first diode, its anode is coupled to a reference voltage source, and its cathode provides the detection signal; A first photodetection transistor has a first terminal, a second terminal and a control terminal, the first terminal of which is coupled to the cathode of the first diode, and the second terminal and the control terminal of the first photodetection transistor are connected to each other coupled to a second reference voltage; a second diode, its anode is coupled to the reference voltage source, and its cathode provides the first reference voltage; and A second photodetection transistor has a first terminal, a second terminal and a control terminal, the first terminal of which is coupled to the cathode of the second diode, and the second terminal and the control terminal of the second photodetection transistor are connected to each other coupled to a third reference voltage. 7. The touch detection circuit according to claim 1, wherein the touch result generating unit comprises: A first transistor has a first terminal, a second terminal and a control terminal, the first terminal of which receives a reference power supply, and the control terminal of the first transistor is coupled to the comparison voltage; and A second transistor has a first terminal, a second terminal and a control terminal, the first terminal of which is coupled to the second terminal of the first transistor, the control terminal of the second transistor receives a scan signal, and the control terminal of the second transistor The second end generates the touch result signal. 8. The touch detection circuit according to claim 1, wherein the touch unit comprises: A touch detection capacitor has a first end and a second end, the first end of the touch detection capacitor receives a detection signal, and the second end of the touch detection capacitor provides the detection signal; and A reference capacitor is connected in series between the second end of the touch detection capacitor and a reference ground end. 9. The touch detection circuit according to claim 8, wherein the touch result generating unit is an analog-to-digital converter. 10. A touch detection circuit, characterized in that it comprises: A touch unit, which provides a detection signal according to the touched state; A comparison unit, coupled to the touch unit, provides a reference current, the comparison unit generates a touch state current according to the voltage difference between the detection signal and a first reference voltage, and the comparison unit compares the reference current and the first reference voltage the touch state current to generate a comparison voltage; and a touch result generating unit coupled to the comparison unit to provide a touch result signal according to the comparison voltage; Among them, the comparison unit includes: A first transistor has a first terminal, a second terminal and a control terminal, the first terminal of which is coupled to a reference voltage source, and the second terminal of which generates the comparison voltage; a diode, its anode is coupled to the second terminal of the first transistor, and its cathode is coupled to the control terminal of the first transistor, the diode is used to generate the reference current; and A second transistor has a first terminal, a second terminal and a control terminal, the first terminal of the first transistor is coupled to the cathode of the diode, the control terminal of the second transistor receives the detection signal, and the second transistor The second terminal of the transistor is coupled to the first reference voltage, and the first transistor generates the touch state current according to the voltage difference between the detection signal and the first reference voltage. 11. The touch detection circuit according to claim 10, wherein the diode is a third transistor having a first terminal, a second terminal and a control terminal, and the first terminal of the third transistor is coupled to The second terminal of the first transistor, the second terminal and the control terminal of the third transistor are jointly coupled to the first terminal of the second transistor.