LED tube driver circuit, infrared emitting circuit, touch screen and interactive flat panel

Abstract

This application provides a light-emitting tube driving circuit, an infrared emitting circuit, a touch screen, and an interactive flat panel. The light-emitting tube driving circuit includes a current driving module and a gain amplification module. The current driving module includes a first driving terminal, a first connection terminal, and a second connection terminal. The gain amplification module includes a second driving terminal, a third connection terminal, and a fourth connection terminal. The first driving terminal of the current driving module is used to receive a stable current regulation control signal. The first connection terminal of the current driving module is connected to the second driving terminal of the gain amplification module, and the second connection terminal of the current driving module is grounded. The third connection terminal of the gain amplification module is connected to a power supply, and the fourth connection terminal of the gain amplification module is used to output a working current to the light-emitting tube. The gain amplification module is used to stabilize the working current according to the current of the second driving terminal. This application can output a stable working current, improving the luminous stability of the light-emitting tube.

Description

Technical Field

[0001] This utility model relates to the field of driving circuit technology for light-emitting tubes, specifically to a driving circuit for light-emitting tubes, an infrared emitting circuit, a touch screen, and an interactive flat panel. Background Technology

[0002] In existing technology, a lamp driver circuit is an electronic circuit connected to the lamp tube and used to drive the lamp tube to its on / off state. Specifically, the lamp driver circuit controls whether to output current to the lamp tube through a switching transistor, thereby achieving switching control of the lamp tube. However, in existing technology, the switching transistor in the lamp driver circuit only functions as a switch. Therefore, when the power supply voltage is unstable, the current output by the lamp driver circuit will be unstable, affecting the current intensity received by the lamp tube, thus affecting the luminous stability of the lamp tube, and may even burn out the lamp tube. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings and deficiencies in the prior art and provide a light-emitting tube driving circuit, an infrared emitting circuit, a touch screen, and an interactive flat panel, which can output a stable operating current to the light-emitting tube and improve the light-emitting stability of the light-emitting tube.

[0004] One embodiment of this utility model provides a light-emitting tube driving circuit, including: a current driving module and a gain amplification module; the current driving module includes a first driving terminal, a first connection terminal and a second connection terminal; the gain amplification module includes a second driving terminal, a third connection terminal and a fourth connection terminal; The first driving terminal of the current driving module is used to receive a stable current regulation control signal. The first connection terminal of the current driving module is connected to the second driving terminal of the gain amplification module, and the second connection terminal of the current driving module is grounded. The current driving module is used to stabilize the current of the second driving terminal of the gain amplification module according to the current regulation control signal. The third connection terminal of the gain amplification module is connected to the power supply, and the fourth connection terminal of the gain amplification module is used to output the working current to the light tube; the gain amplification module is used to stabilize the working current according to the current of the second driving terminal.

[0005] Compared to existing technologies, the LED driving circuit of this utility model includes a current driving module and a gain amplification module. The circuit is based on the following: the first driving terminal of the current driving module receives a stable current regulation control signal; the first connection terminal of the current driving module is connected to the second driving terminal of the gain amplification module, and the second connection terminal of the current driving module is grounded; the third connection terminal of the gain amplification module is connected to the power supply; and the fourth connection terminal of the gain amplification module outputs a working current to the LED. Through the stable current regulation control signal and the current driving module, the current at the second driving terminal of the gain amplification module is stabilized, thereby enabling the gain amplification module to stabilize the working current output from the fourth connection terminal based on the current at the second driving terminal. This achieves the technical effect of outputting a stable working current to the LED, improving the luminous stability of the LED.

[0006] In one implementation, the current drive module includes an NPN transistor and a first resistor; the first resistor includes a first terminal and a second terminal. The base of the NPN transistor is connected to the first end of the first resistor, and the second end of the first resistor is the first driving end of the current driving module; the collector of the NPN transistor is the first connection end of the current driving module; and the emitter of the NPN transistor is the second connection end of the current driving module.

[0007] In this embodiment, based on the function of the base current of the NPN transistor to stabilize the collector current of the NPN transistor, the current drive module can stabilize the current at the second drive terminal of the gain amplification module.

[0008] In one implementation, the gain amplification module includes a second resistor and a PNP transistor; the second resistor includes a third terminal and a fourth terminal; The third terminal of the second resistor is the second driving terminal of the gain amplification module, and the fourth terminal of the second resistor is connected to the base of the PNP transistor; the emitter of the PNP transistor is the third connection terminal of the gain amplification module; and the collector of the PNP transistor is the fourth connection terminal of the gain amplification module.

[0009] In this embodiment, when the base current of the PNP transistor is stable, the collector current of the PNP transistor can be stably controlled, so that the fourth connection terminal of the gain amplifier module can output a stable operating current.

[0010] In one embodiment, the light-emitting tube driving circuit further includes a switch control module; the switch control module includes a third driving terminal, a fifth connection terminal, and a sixth connection terminal; The third driving terminal of the switch control module is used to receive switch control signals, the fifth connection terminal of the switch control module is connected to the base of the PNP transistor, and the sixth connection terminal of the switch control module is connected to the power supply.

[0011] In this embodiment, since the fifth connection terminal of the switch control module is directly connected to the base of the PNP transistor, when the switch control module is turned on, the electrical signal output by the power supply can quickly act on the base of the PNP transistor, thereby rapidly changing the electrical signal at the base of the PNP transistor and improving the switching speed of the PNP transistor.

[0012] In one embodiment, the switch control module includes a third resistor and a switching transistor; the third resistor includes a fifth terminal and a sixth terminal; the switching transistor includes a switch drive terminal, a first switch connection terminal, and a second switch connection terminal. The fifth terminal of the third resistor is the third driving terminal of the switch control module, and the sixth terminal of the third resistor is connected to the switching driving terminal of the switching transistor; the first switching connection terminal of the switching transistor is the fifth connection terminal of the switch control module; and the second switching connection terminal of the switching transistor is the sixth connection terminal of the switch control module.

[0013] In this embodiment, a switch control module is constructed based on the third resistor and the switching transistor. The switching state of the switch control module can be switched according to the conduction state of the switching transistor. When the switching transistor is on, the electrical signal output by the power supply can quickly act on the base of the PNP transistor in the gain amplifier module, thereby quickly changing the electrical signal at the base of the PNP transistor. Moreover, the transistor has a low cost, which can achieve the effect of improving the disconnection speed of the PNP transistor at a low cost.

[0014] In one embodiment, the switch control module includes a field-effect transistor (FET); the gate of the FET is the third driving terminal of the switch control module, the drain of the FET is the fifth connection terminal of the switch control module, and the source of the FET is the sixth connection terminal of the switch control module.

[0015] In this embodiment, the field-effect transistor (FET) is used as a switch control module. The switching state of the switch control module can be switched according to the conduction state of the FET. When the FET is on, the electrical signal output by the power supply can quickly act on the base of the PNP transistor in the gain amplifier module, thereby quickly changing the electrical signal at the base of the PNP transistor and improving the disconnection speed of the PNP transistor.

[0016] A second aspect of this application provides an infrared emitting circuit, including: an infrared emitting module and a light-emitting tube driving circuit as described above; the light-emitting tube driving circuit is connected to the infrared emitting module through the fourth connection terminal of the gain amplification module, and the light-emitting tube driving circuit is used to output a constant operating current to the infrared emitting module.

[0017] Compared to existing technologies, the infrared emitting circuit of this utility model includes a current driving module and a gain amplification module. The circuit structure is as follows: the first driving terminal of the current driving module receives a stable current regulation control signal; the first connection terminal of the current driving module is connected to the second driving terminal of the gain amplification module, and the second connection terminal of the current driving module is grounded; the third connection terminal of the gain amplification module is connected to the power supply; and the fourth connection terminal of the gain amplification module outputs a working current to the infrared emitting module. Through the stable current regulation control signal and the current driving module, the current at the second driving terminal of the gain amplification module is stabilized, thereby enabling the gain amplification module to stabilize the working current output from the fourth connection terminal based on the current at the second driving terminal. This achieves the technical effect of outputting a stable working current to the infrared emitting module and improving the luminous stability of the infrared emitting module.

[0018] In one implementation, the infrared light-emitting module includes a light-emitting diode and a protection resistor; The anode of the light-emitting diode is connected to the fourth connection terminal of the gain amplification module, and the cathode of the light-emitting diode is grounded through the protection resistor.

[0019] In this embodiment, based on the current-limiting function of the protective resistor, when the LED driving circuit malfunctions and cannot stably output the working current, the current flowing through the LED can be limited by the protective resistor to protect the LED.

[0020] A third aspect of this application provides a touch screen, including: a screen, an infrared light-emitting module, and a light-emitting tube driving circuit as described above; The infrared light-emitting module is arranged around the screen, and the light emitted by the infrared light-emitting module covers the screen. The light-emitting tube driving circuit is connected to the infrared light-emitting module through the fourth connection terminal of the gain amplification module. The light-emitting tube driving circuit is used to output a constant operating current to the infrared light-emitting module.

[0021] A fourth aspect of this application provides a touch screen, including: a tablet body, a display screen, an infrared light-emitting module, and a light-emitting tube driving circuit as described above; The display screen is disposed on the outer surface of the tablet body, the infrared light-emitting module is disposed around the display screen, the light emitted by the infrared light-emitting module covers the display screen, the light-emitting tube driving circuit is connected to the infrared light-emitting module through the fourth connection terminal of the gain amplification module, and the light-emitting tube driving circuit is used to output a constant current to the infrared light-emitting module.

[0022] To provide a clearer understanding of this invention, the specific embodiments of the invention will be described below in conjunction with the accompanying drawings. Attached Figure Description

[0023] Figure 1 This is a circuit diagram of a current-technical LED tube driver circuit.

[0024] Figure 2 This is a schematic diagram of the connection of a light-emitting tube driving circuit according to an embodiment of the present invention.

[0025] Figure 3 This is a circuit diagram of a light-emitting tube driving circuit according to an embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of the connection of an infrared emitting circuit according to an embodiment of the present invention.

[0027] Figure 5 This is a circuit diagram of an infrared emitting circuit according to an embodiment of the present invention.

[0028] Figure 6 This is a schematic diagram of a touch screen according to an embodiment of the present invention.

[0029] Figure 7 This is a schematic diagram of an interactive flat panel according to an embodiment of the present invention.

[0030] 100. Light-emitting tube driving circuit; 110. Current driving module; 130. Gain amplification module; 150. Switch control module; 200. Infrared emitting circuit; 210. Infrared emitting module; 300. Touch screen; 310. Screen; 400. Interactive flat panel; 410. Flat panel body; 430. Display screen. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] Please see Figure 1In existing technology, the switching transistor in the LED tube driver circuit only functions as a switch, such as... Figure 1 As shown, transistors QA1 and QA2 in the LED driver circuit only function as switches. When both transistors QA1 and QA2 are in the conducting state, if the power supply voltage is unstable, the base voltage of transistor QA2 will also be unstable due to the stable PN junction voltage drop between the emitter and base of transistor QA2. This leads to unstable voltage across resistor RG2, and consequently, unstable current flowing through resistor RG2. In other words, the base current of transistor QA2 is unstable, preventing the collector of transistor QA2 from outputting a stable operating current to the LED.

[0033] This application stabilizes the current at the second drive terminal of the gain amplification module by using a stable current regulation control signal and a current drive module. This allows the gain amplification module to stabilize the operating current output from the fourth connection terminal based on the current at the second drive terminal, thereby achieving a stable operating current output to the light-emitting tube and improving the luminous stability of the light-emitting tube.

[0034] Please see Figure 2 This is a connection diagram of a light-emitting tube driving circuit 100 according to an embodiment of the present invention, including: a current driving module 110 and a gain amplification module 130; the current driving module 110 includes a first driving terminal, a first connecting terminal and a second connecting terminal; the gain amplification module 130 includes a second driving terminal, a third connecting terminal and a fourth connecting terminal; The first drive terminal of the current drive module 110 is used to receive a stable current adjustment control signal DAC. The first connection terminal of the current drive module 110 is connected to the second drive terminal of the gain amplifier module 130, and the second connection terminal of the current drive module 110 is grounded. The current drive module 110 is used to stabilize the current of the second drive terminal of the gain amplifier module 130 according to the current adjustment control signal DAC. The third connection terminal of the gain amplifier module 130 is connected to the power supply, and the fourth connection terminal of the gain amplifier module 130 is used to output the working current to the light tube; the gain amplifier module 130 is used to stabilize the working current according to the current of the second driving terminal.

[0035] The working principle of this embodiment is as follows: The current driving module 110 stabilizes the current flowing through the first connection terminal of the current driving module 110 according to the stable current adjustment control signal DAC received from the first driving terminal. Since the first connection terminal of the current driving module 110 is connected in series with the second driving terminal of the gain amplification module 130, the current flowing through the second driving terminal of the gain amplification module 130 is the same as the current flowing through the first connection terminal of the current driving module 110. That is, the current driving module 110 can stabilize the current flowing through the second driving terminal of the gain amplification module 130 according to the stable current adjustment control signal DAC received from the first driving terminal, thereby enabling the gain amplification module 130 to stably control the operating current output from the fourth connection terminal of the gain amplification module 130 according to the current of the second driving terminal.

[0036] Compared to existing technologies, the LED driving circuit 100 of this utility model includes a current driving module 110 and a gain amplification module 130. The circuit is based on the following: the first driving terminal of the current driving module 110 receives a stable current regulation control signal DAC; the first connection terminal of the current driving module 110 is connected to the second driving terminal of the gain amplification module 130, and the second connection terminal of the current driving module 110 is grounded; the third connection terminal of the gain amplification module 130 is connected to a power supply; and the fourth connection terminal of the gain amplification module 130 is used to output a working current to the LED. Through the stable current regulation control signal DAC and the current driving module 110, the current at the second driving terminal of the gain amplification module 130 is stabilized, thereby enabling the gain amplification module 130 to stabilize the working current output from the fourth connection terminal based on the current at the second driving terminal. This achieves the technical effect of outputting a stable working current to the LED, improving the luminous stability of the LED.

[0037] Please see Figure 3 In one feasible embodiment, the current drive module 110 includes an NPN transistor QT1 and a first resistor RG1; the first resistor RG1 includes a first terminal and a second terminal; The base of NPN transistor QT1 is connected to the first end of the first resistor RG1, and the second end of the first resistor RG1 is the first driving end of the current driving module 110; the collector of NPN transistor QT1 is the first connection end of the current driving module 110; and the emitter of NPN transistor QT1 is the second connection end of the current driving module 110.

[0038] In this embodiment, based on the function of the base current of NPN transistor QT1 to stabilize the collector current of NPN transistor QT1, the current drive module 110 can stabilize the current at the second drive terminal of the gain amplification module 130.

[0039] In one feasible embodiment, the gain amplification module 130 includes a second resistor RG2 and a PNP transistor QA2; the second resistor RG2 includes a third terminal and a fourth terminal; The third terminal of the second resistor RG2 is the second driving terminal of the gain amplifier module 130, and the fourth terminal of the second resistor RG2 is connected to the base of the PNP transistor QA2; the emitter of the PNP transistor QA2 is the third connection terminal of the gain amplifier module 130; and the collector of the PNP transistor QA2 is the fourth connection terminal of the gain amplifier module 130.

[0040] In this embodiment, when the base current of the PNP transistor QA2 is stable, the collector current of the PNP transistor QA2 can be stably controlled, so that the fourth connection terminal of the gain amplifier module 130 can output a stable operating current.

[0041] Specifically, when the current regulation control signal DAC is input to the base of NPN transistor QT1 via the first resistor RG1, the voltage between the base and emitter of NPN transistor QT1 is greater than the turn-on voltage of NPN transistor QT1, which meets the turn-on condition of NPN transistor QT1. At this time, the base of PNP transistor QA2 is grounded to NPN transistor QT1 via the second resistor RG2. Therefore, the voltage between the base and emitter of PNP transistor QA2 is less than the turn-on voltage of PNP transistor QA2, which meets the turn-on condition of PNP transistor QA2.

[0042] When NPN transistor QT1 and PNP transistor QA2 are turned on, the base current of NPN transistor QT1 can stably control the collector current of NPN transistor QT1. Since the base of PNP transistor QA2 is connected to the collector of NPN transistor QT1 through the second resistor RG2, the base current of PNP transistor QA2 is the same as the collector current of NPN transistor QT1 (current I2). That is, based on the stable current regulation control signal DAC and NPN transistor QT1, the base current of PNP transistor QA2 can be stably controlled. And based on the base current of PNP transistor QA2, PNP transistor QA2 can stably control the collector current of PNP transistor QA2, so that the collector of PNP transistor QA2 can output a stable operating current.

[0043] In one feasible embodiment, the light-emitting tube driving circuit 100 further includes a switch control module 150; the switch control module 150 includes a third driving terminal, a fifth connection terminal and a sixth connection terminal. The third drive terminal of the switch control module 150 is used to receive the switch control signal, the fifth connection terminal of the switch control module 150 is connected to the base of the PNP transistor QA2, and the sixth connection terminal of the switch control module 150 is connected to the power supply.

[0044] When the switch control module 150 is in the off state, the current drive module 110 can control the PNP transistor QA2 normally. When the switch control module 150 is in the on state, the base of the PNP transistor QA2 is connected to the power supply through the switch control module 150, which can quickly increase the voltage of the base of the PNP transistor QA2, so that the PNP transistor QA2 does not meet the conduction condition, thereby quickly turning off the PNP transistor QA2.

[0045] In this embodiment, since the fifth connection terminal of the switch control module 150 is directly connected to the base of the PNP transistor QA2, when the switch control module 150 is turned on, the electrical signal output by the power supply can quickly act on the base of the PNP transistor QA2, thereby quickly changing the electrical signal at the base of the PNP transistor QA2 and improving the turning-off speed of the PNP transistor QA2.

[0046] In one feasible embodiment, the switch control module 150 includes a third resistor RG4 and a switching transistor QA3; the third resistor RG4 includes a fifth terminal and a sixth terminal; the switching transistor QA3 includes a switch drive terminal, a first switch connection terminal and a second switch connection terminal; The fifth terminal of the third resistor RG4 is the third driving terminal of the switch control module 150, and the sixth terminal of the third resistor RG4 is connected to the switching driving terminal of the switching transistor QA3; the first switching connection terminal of the switching transistor QA3 is the fifth connection terminal of the switch control module 150; and the second switching connection terminal of the switching transistor QA3 is the sixth connection terminal of the switch control module 150.

[0047] Among them, the switching transistor QA3 can be a PNP transistor.

[0048] In this embodiment, a switch control module 150 is constructed based on the third resistor RG4 and the switching transistor QA3. The switching state of the switch control module 150 can be switched according to the conduction state of the switching transistor QA3. When the switching transistor QA3 is on, the electrical signal output by the power supply can quickly act on the base of the PNP transistor QA2 in the gain amplifier module 130, thereby quickly changing the electrical signal at the base of the PNP transistor QA2. Moreover, the transistor has a low cost, which can achieve the effect of improving the disconnection speed of the PNP transistor QA2 at low cost.

[0049] In one feasible embodiment, the switch control module 150 includes a field-effect transistor (FET); the gate of the FET is the third driving terminal of the switch control module 150, the drain of the FET is the fifth connection terminal of the switch control module 150, and the source of the FET is the sixth connection terminal of the switch control module 150.

[0050] Among them, PMOS transistors can be used as field-effect transistors.

[0051] In this embodiment, the field-effect transistor is used as the switch control module 150. The switching state of the switch control module 150 can be switched according to the conduction state of the field-effect transistor. When the field-effect transistor is on, the electrical signal output by the power supply can quickly act on the base of the PNP transistor QA2 in the gain amplifier module 130, thereby quickly changing the electrical signal at the base of the PNP transistor QA2 and improving the disconnection speed of the PNP transistor QA2.

[0052] Please see Figure 4 The second aspect of this application provides an infrared emitting circuit 200, including an infrared emitting module 210 and a light-emitting tube driving circuit 100 as described above; the light-emitting tube driving circuit 100 is connected to the infrared emitting module 210 through the fourth connection terminal of the gain amplification module 130, and the light-emitting tube driving circuit 100 is used to output a constant current to the infrared emitting module 210.

[0053] Compared to existing technologies, the infrared emitting circuit 200 of this utility model includes a current driving module 110 and a gain amplification module 130. Based on the circuit relationship where the first driving terminal of the current driving module 110 receives a stable current regulation control signal DAC, the first connection terminal of the current driving module 110 is connected to the second driving terminal of the gain amplification module 130, and the second connection terminal of the current driving module 110 is grounded; the third connection terminal of the gain amplification module 130 is connected to a power supply, and the fourth connection terminal of the gain amplification module 130 is used to output operating current to the infrared emitting module 210, the current at the second driving terminal of the gain amplification module 130 is stabilized through the stable current regulation control signal DAC and the current driving module 110. This allows the gain amplification module 130 to stabilize the operating current output from the fourth connection terminal based on the current at the second driving terminal, thereby achieving a stable operating current output to the infrared emitting module 210 and improving the luminous stability of the infrared emitting module 210.

[0054] Please see Figure 5 In one feasible embodiment, the infrared emitting module 210 includes a light-emitting diode IR1 and a protection resistor RH1; The anode of LED IR1 is connected to the fourth connection terminal of gain amplifier module 130, and the cathode of LED IR1 is grounded through protection resistor RH1.

[0055] In this embodiment, based on the current limiting function of the protection resistor RH1, when the light-emitting diode IR1 fails to output stable operating current due to an abnormality in the light-emitting diode driving circuit 100, the current flowing through the light-emitting diode IR1 can be limited by the protection resistor RH1 to protect the light-emitting diode IR1.

[0056] Please see Figure 6 The third aspect of the application provides a touch screen 300, including: a screen 310, an infrared light-emitting module 210, and a light-emitting tube driving circuit 100 as described above; The infrared light-emitting module 210 is arranged around the screen 310. The light emitted by the infrared light-emitting module 210 covers the screen 310. The light-emitting tube driving circuit 100 is connected to the infrared light-emitting module 210 through the fourth connection terminal of the gain amplification module 130. The light-emitting tube driving circuit 100 is used to output a constant working current to the infrared light-emitting module 210.

[0057] Please see Figure 7 The fourth aspect of this application provides a touch screen 300, including: a tablet body 410, a display screen 430, an infrared light-emitting module 210, and a light-emitting tube driving circuit 100 as described above; The display screen 430 is disposed on the outer surface of the tablet body 410. The infrared light-emitting module 210 is disposed around the display screen 430. The light emitted by the infrared light-emitting module 210 covers the display screen 430. The light-emitting tube driving circuit 100 is connected to the infrared light-emitting module 210 through the fourth connection terminal of the gain amplification module 130. The light-emitting tube driving circuit 100 is used to output a constant current to the infrared light-emitting module 210.

[0058] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A light-emitting tube driving circuit, characterized in that, include: A current-driven module and a gain-amplifying module are provided; the current-driven module includes a first driving terminal, a first connecting terminal, and a second connecting terminal; the gain-amplifying module includes a second driving terminal, a third connecting terminal, and a fourth connecting terminal. The first driving terminal of the current driving module is used to receive a stable current regulation control signal. The first connection terminal of the current driving module is connected to the second driving terminal of the gain amplification module, and the second connection terminal of the current driving module is grounded. The current driving module is used to stabilize the current of the second driving terminal of the gain amplification module according to the current regulation control signal. The third connection terminal of the gain amplification module is connected to the power supply, and the fourth connection terminal of the gain amplification module is used to output the working current to the light tube; the gain amplification module is used to stabilize the working current according to the current of the second driving terminal.

2. The light-emitting tube driving circuit according to claim 1, characterized in that: The current drive module includes an NPN transistor and a first resistor; the first resistor includes a first terminal and a second terminal. The base of the NPN transistor is connected to the first end of the first resistor, and the second end of the first resistor is the first driving end of the current driving module; the collector of the NPN transistor is the first connection end of the current driving module; and the emitter of the NPN transistor is the second connection end of the current driving module.

3. The light-emitting tube driving circuit according to claim 1, characterized in that: The gain amplification module includes a second resistor and a PNP transistor; the second resistor includes a third terminal and a fourth terminal; The third terminal of the second resistor is the second driving terminal of the gain amplification module, and the fourth terminal of the second resistor is connected to the base of the PNP transistor; the emitter of the PNP transistor is the third connection terminal of the gain amplification module; and the collector of the PNP transistor is the fourth connection terminal of the gain amplification module.

4. The light-emitting tube driving circuit according to claim 3, characterized in that: The light-emitting tube driving circuit also includes a switch control module; the switch control module includes a third driving terminal, a fifth connection terminal and a sixth connection terminal; The third driving terminal of the switch control module is used to receive switch control signals, the fifth connection terminal of the switch control module is connected to the base of the PNP transistor, and the sixth connection terminal of the switch control module is connected to the power supply.

5. The light-emitting tube driving circuit according to claim 4, characterized in that: The switch control module includes a third resistor and a switching transistor; the third resistor includes a fifth terminal and a sixth terminal; the switching transistor includes a switch drive terminal, a first switch connection terminal, and a second switch connection terminal. The fifth terminal of the third resistor is the third driving terminal of the switch control module, and the sixth terminal of the third resistor is connected to the switching driving terminal of the switching transistor; the first switching connection terminal of the switching transistor is the fifth connection terminal of the switch control module; and the second switching connection terminal of the switching transistor is the sixth connection terminal of the switch control module.

6. The light-emitting tube driving circuit according to claim 4, characterized in that: The switch control module includes a field-effect transistor (FET); the gate of the FET is the third driving terminal of the switch control module, the drain of the FET is the fifth connection terminal of the switch control module, and the source of the FET is the sixth connection terminal of the switch control module.

7. An infrared emitting circuit, characterized in that, include: An infrared light-emitting module, and a light-emitting tube driving circuit as described in any one of claims 1 to 6; The light-emitting tube driving circuit is connected to the infrared light-emitting module through the fourth connection terminal of the gain amplification module. The light-emitting tube driving circuit is used to output a constant operating current to the infrared light-emitting module.

8. An infrared emitting circuit according to claim 7, characterized in that: The infrared light-emitting module includes a light-emitting diode and a protection resistor; The anode of the light-emitting diode is connected to the fourth connection terminal of the gain amplification module, and the cathode of the light-emitting diode is grounded through the protection resistor.

9. A touchscreen, characterized in that, include: The screen, the infrared light-emitting module, and the light-emitting tube driving circuit as described in any one of claims 1 to 6; The infrared light-emitting module is arranged around the screen, and the light emitted by the infrared light-emitting module covers the screen. The light-emitting tube driving circuit is connected to the infrared light-emitting module through the fourth connection terminal of the gain amplification module. The light-emitting tube driving circuit is used to output a constant operating current to the infrared light-emitting module.

10. An interactive flat panel, characterized in that, Includes: a tablet body, a display screen, an infrared light-emitting module, and a light-emitting tube driving circuit as described in any one of claims 1 to 6; The display screen is disposed on the outer surface of the tablet body, the infrared light-emitting module is disposed around the display screen, the light emitted by the infrared light-emitting module covers the display screen, the light-emitting tube driving circuit is connected to the infrared light-emitting module through the fourth connection terminal of the gain amplification module, and the light-emitting tube driving circuit is used to output a constant current to the infrared light-emitting module.

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