Infrared signal gain adjusting circuit, touch screen and interactive panel

Abstract

The embodiment of the utility model provides an infrared signal gain adjusting circuit, a touch screen and an interactive tablet, and the circuit comprises an infrared signal output module, an isolation module and a gain adjusting module. The output end of the infrared signal output module is used for outputting a received infrared signal, the output end of the infrared signal output module is connected with the input end of the isolation module, and the output end of the isolation module is connected with the gain adjustment module; the isolation module comprises a capacitor and a first resistor, one end of the capacitor is the input end of the isolation module, the other end of the capacitor is the output end of the isolation module, one end of the first resistor is connected with the output end of the isolation module, and the other end of the first resistor is grounded. The circuit structure is simple, the number of used elements is small, the cost is low, and the circuit cost is greatly reduced.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of infrared touch technology, and in particular, to an infrared signal gain adjustment circuit, a touch screen, and an interactive flat panel. Background Art

[0002] Various intelligent touch devices, especially large-screen interactive flat panels, are used more and more frequently in life or work. Among them, an infrared touch electronic device includes a plurality of infrared transmitters and infrared receivers arranged distributively. The infrared transmitters emit infrared signals under the control of a controller, and the corresponding infrared receivers receive the infrared signals. The controller collects and processes the infrared signals, and judges whether the infrared light is blocked by a touch object by detecting the change of the infrared signals, so as to realize the touch function.

[0003] In practical applications, the gain of the infrared signal can be automatically adjusted by a gain adjustment module, so that the processed signal is neither too large nor too small, but within a reasonable range that can be collected by a Microcontroller Unit (MCU). Since the impedance of the gain adjustment module changes dynamically, if the infrared signal is directly input into the gain adjustment module, the output signal will change with the change of the impedance of the gain adjustment module, and the signal becomes unstable. Therefore, the infrared signal can be first isolated and enhanced by an operational amplifier isolation drive circuit, and then the output signal is adjusted by the gain adjustment module, so that the gain adjustment module will not affect the input signal. However, this operational amplifier isolation drive circuit structure requires an operational amplifier, which is an integrated circuit, and the circuit is relatively complex and the cost is high. Summary of the Invention

[0004] To overcome the problems existing in the related art, the present application provides an infrared signal gain adjustment circuit, a touch screen, and an interactive flat panel, which can realize a simple structure and low cost of the infrared signal gain adjustment circuit without the gain adjustment module affecting the input signal.

[0005] According to the first aspect of the embodiments of the present application, an infrared signal gain adjustment circuit is provided, and the circuit includes: an infrared signal output module, an isolation module, and a gain adjustment module;

[0006] The output end of the infrared signal output module is used to output the received infrared signal. The output end of the infrared signal output module is connected to the input end of the isolation module, and the output end of the isolation module is connected to the gain adjustment module;

[0007] The isolation module includes a capacitor and a first resistor. One end of the capacitor is the input end of the isolation module, and the other end of the capacitor is the output end of the isolation module. One end of the first resistor is connected to the output end of the isolation module, and the other end of the first resistor is grounded.

[0008] According to a second aspect of the embodiments of the present application, a touch screen is provided, including: a screen and the infrared signal gain adjustment circuit as described above, and the infrared signal gain adjustment circuit adjusts and processes the infrared signals received by the infrared receiving tubes arranged around the screen.

[0009] According to a second aspect of the embodiments of the present application, an interactive flat panel is provided, characterized by including: a display screen and the infrared signal gain adjustment circuit as described above, and the infrared signal gain adjustment circuit adjusts and processes the infrared signals received by the infrared receiving tubes arranged around the display screen.

[0010] In the infrared signal gain adjustment circuit of the embodiments of the present application, since the isolation module has a low output impedance through the capacitor and the first resistor, even if the impedance of the gain adjustment module changes dynamically during gain adjustment, the infrared signal will not change due to the increase or decrease of the impedance. The isolation module in the embodiments of the present application may include a capacitor and a first resistor. One end of the capacitor is the input end of the isolation module, and the other end of the capacitor is the output end of the isolation module. One end of the first resistor is connected to the output end of the isolation module, and the other end of the first resistor is grounded. It can be seen that the circuit structure is simple and the cost is low.

[0011] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application.

[0012] For better understanding and implementation, the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. Description of the Drawings

[0013] Figure 1 is a schematic diagram of an infrared signal gain adjustment circuit in the prior art;

[0014] Figure 2 is a schematic diagram of an infrared signal gain adjustment circuit shown according to an exemplary embodiment of the present application;

[0015] Figure 3 is another schematic diagram of an infrared signal gain adjustment circuit shown according to an exemplary embodiment of the present application;

[0016] Figure 4 is another schematic diagram of an infrared signal gain adjustment circuit shown according to an exemplary embodiment of the present application;

[0017] Figure 5It is a schematic diagram of another infrared signal gain adjustment circuit shown according to an exemplary embodiment of the present application;

[0018] Figure 6 It is a schematic diagram of another infrared signal gain adjustment circuit shown according to an exemplary embodiment of the present application. Detailed implementation manners

[0019] To make the objectives, technical solutions and advantages of the present application clearer, the embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

[0020] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0021] When the following description relates to the accompanying drawings, unless otherwise indicated, the same numerals in different drawings represent the same or similar elements.

[0022] In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and do not have to be used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances. The singular forms of "a", "the" and "said" used in the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. The word "if" / "when" used herein can be interpreted as "when...", "when...", or "in response to a determination". In addition, in the description of the present application, unless otherwise stated, "a plurality of" means two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B, which can mean: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0023] In an infrared touch frame, the infrared touch frame may include a plurality of relatively distributed infrared transmitters and infrared receivers. The infrared transmitters are turned on and emit infrared signals under the control of a controller, and the corresponding infrared receivers are turned on and receive infrared signals under the control of the controller. After a plurality of infrared receivers receive the infrared signals emitted by the same infrared transmitter, the infrared signals can be gain-adjusted through a gain adjustment signal, so that the signal intensity values of the infrared signals of the plurality of infrared receivers are adjusted to a target value. When a user touches, the MCU calculates whether a touch operation occurs according to the change of the adjusted infrared signal.

[0024] In practical applications, the gain of the infrared signal can be automatically adjusted by the gain adjustment module, so that the processed signal is neither too large nor too small, but within a reasonable range that can be collected by the MCU. Since the impedance of the gain adjustment module is dynamically changing, if the infrared electrical signal is directly input into the gain adjustment module, the output signal will change with the change of the impedance of the gain adjustment module, and the signal will become unstable. Therefore, as Figure 1 shown Figure 1 is a schematic diagram of an infrared signal gain adjustment circuit in the prior art. The infrared signal can be isolated and enhanced by the operational amplifier isolation drive circuit first, and then the output signal can be gain-adjusted by the gain adjustment module, so that the gain adjustment module will not affect the input signal. However, this operational amplifier isolation drive circuit structure requires the use of operational amplifier UIC, capacitor C1, and resistors R2 and R3, and the circuit is relatively complex. Especially with the operational amplifier, the cost is relatively high.

[0025] Based on this, the present application uses a simple circuit with the characteristics of DC isolation and low output impedance to replace the operational amplifier isolation drive circuit. The inventor found that by combining a capacitor and a first resistor to obtain an isolation module and connecting the gain adjustment module to the output end of the isolation module, not only the circuit structure is simple, the components used are few and the cost of the components themselves is low, but also the circuit cost is greatly reduced.

[0026] In one embodiment, as Figure 2 shown Figure 2 is a schematic diagram of an infrared signal gain adjustment circuit shown in an exemplary embodiment of the present application. The infrared signal gain adjustment circuit may include: an infrared signal output module 21, an isolation module 22, and a gain adjustment module 23. The output end of the infrared signal output module 21 is used to output the received infrared signal. The output end of the infrared signal output module 21 is connected to the input end of the isolation module 22, and the output end of the isolation module 22 is connected to the gain adjustment module 23. The isolation module 22 includes a capacitor 221 and a first resistor 222. One end of the capacitor 221 is the input end of the isolation module 22, and the other end of the capacitor 221 is the output end of the isolation module 22. One end of the first resistor 222 is connected to the output end of the isolation module 22, and the other end of the first resistor 222 is grounded.

[0027] Among them, the infrared signal output by the infrared signal output module can be the signal received by the infrared receiving tube, or the signal after processing the signal received by the infrared receiving tube. For example, in one embodiment, the infrared signal can be an infrared electrical signal converted from the received initial infrared signal. For example, the infrared signal output module can include an infrared receiving tube circuit. For the convenience of subsequent adjustment and processing, the infrared electrical signal converted from the received initial infrared signal can be obtained through the infrared receiving tube circuit. Another example is that the infrared signal output module can be a transmission module that transmits the signal received by the infrared receiving tube to the isolation module.

[0028] In practical applications, some initial infrared signals are relatively weak after being converted into infrared electrical signals. Therefore, the infrared electrical signal can be amplified. Thus, in another embodiment, to avoid the converted output infrared electrical signal being very weak, the infrared signal can also be: the signal obtained by converting the received initial infrared signal into an infrared electrical signal and then amplifying the infrared electrical signal. Based on this, in one example, the infrared signal output module not only includes an infrared receiving tube circuit but also a first amplifier circuit. In this example, the infrared signal output module can not only convert the received initial infrared signal into an infrared electrical signal but also amplify the infrared electrical signal so that it can be normally collected by the MCU subsequently, avoiding signal loss.

[0029] In another example, the infrared signal output module can include a first amplifier circuit that amplifies the signal output by the infrared receiving tube circuit. In this example, the infrared receiving tube circuit can be independent of the infrared signal gain adjustment circuit, facilitating the manufacturer to produce the infrared signal gain adjustment circuit and reducing the production difficulty.

[0030] In practical applications, in an infrared touch frame, several infrared receivers can be arranged. In one example, each infrared receiver is correspondingly configured with a corresponding infrared signal gain adjustment circuit for targeted adjustment. In view of this, each infrared signal output module is connected to an isolation module. However, as the number of infrared receivers in the infrared touch frame increases, each infrared receiver being correspondingly configured with a corresponding infrared signal gain adjustment circuit will result in increased costs, and some infrared receivers do not receive infrared signals simultaneously. Therefore, multiple infrared receivers can share the same infrared signal gain adjustment circuit. For example, the input end of the isolation module can be connected to at least two infrared signal output modules, thereby reducing costs and saving space in the infrared touch screen circuit.

[0031] The capacitor in the isolation module can be used to isolate the infrared signal output module from the gain adjustment module, so that the DC level of the infrared signal output module can ensure that the signal remains in a stable potential state within a certain time range. The first resistor can be used to achieve a low output impedance of the isolation module. The gain adjustment module is connected to the output end of the isolation module. Since the output impedance of the isolation module is low, it can be ensured that the input signal will not change due to the change in the resistance value of the gain adjustment module.

[0032] In one embodiment, the isolation module can be a circuit with a high input impedance and a low output impedance. The input end of the isolation module is connected to the output end of the infrared signal output module. Since the input impedance is high, it will not affect the input signal. The output end of the isolation module is connected to the input end of the gain adjustment module. Since the output impedance is low, it will not affect the gain adjustment module. Thus, the use of an operational amplifier as an enhancement drive and isolation circuit is saved, the circuit structure is greatly simplified, and the cost is saved.

[0033] For example, the isolation module may include a high-pass passive filter circuit composed of a capacitor and a first resistor. The inventor found that the high-pass passive filter circuit not only has a simple structure, but also greatly reduces the circuit cost. At the same time, the high-pass passive filter circuit can further filter out the noise of the circuit and improve the signal-to-noise ratio.

[0034] Among them, the component parameters in the high-pass passive filter circuit can be adjusted in advance according to the impedance of the gain adjustment module, so that the change in the impedance of the gain adjustment module will not affect the input signal. In practical applications, the component parameters in the high-pass passive filter circuit can be adjusted from different dimensions according to the requirements of the usage scenario. For example, an oscilloscope can be used to detect whether the output voltage of the high-pass passive filter circuit is the first preset target value when there is an input signal and whether the output voltage is the second preset target value when the input signal is 0, so as to adjust the component parameters in the high-pass passive filter circuit. Another example is that the component parameters of the high-pass passive filter circuit can be adjusted so that adjacent input signals do not affect each other. Specifically, between the two wave peaks of the input signal, after blocking the signal of the first wave peak (i.e., the first wave peak becomes 0), the component parameters of the high-pass passive filter circuit are adjusted so that the signal of the second wave peak remains unchanged.

[0035] In a specific embodiment, as Figure 3 shown, Figure 3It is a schematic diagram of another infrared signal gain adjustment circuit shown according to an exemplary embodiment of the present application. The capacitor in the isolation module can be an adjustable capacitor C1, and the first resistor in the isolation module is an adjustable resistor R1 configured to set a low resistance value. The capacitor in the isolation module can play an isolation role. Since the resistance value of the adjustable resistor is very small, the connected resistance value is almost equal to the resistance value of the adjustable resistor and is hardly affected by the increase or decrease of the resistance value in the gain adjustment module. In this way, the signal output by the adjustable capacitor will not change due to the increase or decrease of the resistance value in the gain adjustment module. When the gain adjustment module does not affect the input signal, since the high-pass filter circuit is very simple, the circuit structure is simplified and the cost is saved. At the same time, the high-pass filter circuit can further filter out the noise of the circuit and improve the signal-to-noise ratio.

[0036] In order to achieve a high input impedance and a low output impedance for the isolation module, in one example, the input impedance of the isolation module is at least 10 times the output impedance of the infrared signal output module, and the input impedance of the gain adjustment module is at least 10 times the output impedance of the isolation module.

[0037] Regarding the connection of the gain adjustment module to the output end of the isolation module, in one example, the gain adjustment module can be connected to the isolation module in the form of a load of the isolation module. For example, as Figure 3 shown, the input end of the gain adjustment module is connected to the output end of the isolation module, the first end of the gain adjustment module is used as the output end, and the second end of the gain adjustment module is grounded. Since the output impedance of the isolation module is low and can play an isolation role, and the gain adjustment module is connected to the isolation module in the form of a load, the connected resistance value is almost equal to the resistance value of the first resistor and is hardly affected by the increase or decrease of the resistance value in the gain adjustment module. Therefore, the input signal will not change due to the change of the resistance value of the gain adjustment module. It should be understood that the gain adjustment module can also be connected to the isolation module as a load in other connection ways, which will not be elaborated here one by one.

[0038] The gain adjustment module in the embodiment of the present application is a module that can adjust the gain of the infrared signal so that the signal intensity value of the adjusted infrared signal is within a preset range. In one of the embodiments, the gain adjustment module may include: a first voltage division circuit composed of a field effect transistor and a second resistor. In another embodiment, the gain adjustment module may include: a second voltage division circuit composed of a triode and a third resistor. The gain of the infrared signal is adjusted through the first voltage division circuit or the second voltage division circuit, and the circuit structure is simple.

[0039] Specifically, in one example, one end of the second resistor is the input end of the gain adjustment module, and the other end of the second resistor is the output end of the gain adjustment module; the gate of the field effect transistor is used to receive the gain adjustment signal; the drain of the field effect transistor is connected to the output end of the gain adjustment module, and the source of the field effect transistor is grounded. Among them, one end of the second resistor is the input end of the gain adjustment module and can be connected to the output end of the isolation module. As Figure 4 shown, Figure 4 FIG. 2 is another schematic diagram of an infrared signal gain adjustment circuit shown according to an exemplary embodiment of the present application. One end of the capacitor C1 is used as the input end of the isolation module and is connected to the output end of the infrared signal output module; the other end of the capacitor C1 is the output end of the isolation module and is connected to the input end of the second resistor R2. One end of the first resistor R1 is connected to the output end of the isolation module, and the other end of the first resistor R1 is grounded. The input end of the second resistor R2 is the input end of the gain adjustment module, and the output end of the second resistor R2 is the output end of the gain adjustment module. The gate of the field effect transistor Q1 can be connected to the control module to receive the gain adjustment signal output by the control module. The drain of the field effect transistor Q1 is connected to the output end of the gain adjustment module, and the source of the field effect transistor Q1 is grounded. In this embodiment, while ensuring that the gain adjustment module does not affect the input signal, both the isolation module and the gain adjustment module simplify the circuit structure and save costs. At the same time, the isolation module can further filter out the noise of the circuit and improve the signal-to-noise ratio.

[0040] In another example, the gate of the field effect transistor is used to receive the gain adjustment signal; the drain of the field effect transistor is the input end of the gain adjustment module and can be connected to the output end of the isolation module; the source of the field effect transistor is the output end of the gain adjustment module; one end of the third resistor is connected to the output end of the gain adjustment module, and the other end of the third resistor is grounded. As Figure 5 shown, Figure 5 FIG. 3 is another schematic diagram of an infrared signal gain adjustment circuit shown according to an exemplary embodiment of the present application. One end of the capacitor C1 is used as the input end of the isolation module and is connected to the output end of the infrared signal output module. The other end of the capacitor C1 is the output end of the isolation module and is connected to the drain of the field effect transistor Q1. One end of the first resistor R1 is connected to the output end of the isolation module, and the other end of the first resistor R1 is grounded. The source of the field effect transistor Q1 is the output end of the gain adjustment module; the gate of the field effect transistor Q1 is used to receive the gain adjustment signal. One end of the third resistor R2 is connected to the output end of the gain adjustment module, and the other end of the third resistor R2 is grounded. In this embodiment, while ensuring that the gain adjustment module does not affect the input signal, both the isolation module and the gain adjustment module simplify the circuit structure and save costs. At the same time, the isolation module can further filter out the noise of the circuit and improve the signal-to-noise ratio.

[0041] It should be understood that in practical applications, Figure 4 and Figure 5 the components such as the capacitor C1, resistor R1, field effect transistor Q1, and resistor R2 in [[ ]] may be different. The same names are used in the two figures only for convenience of understanding, and are not limited to the same component. The components with corresponding parameters are specifically selected according to the circuit requirements. In addition, the second voltage dividing circuit composed of a triode and a third resistor and the first voltage dividing circuit composed of a field effect transistor and a second resistor have similar concepts, which will not be elaborated here one by one.

[0042] In practical applications, the signal intensity of the signal output by the gain adjustment module may also be relatively weak. In view of this, in one example, the infrared signal gain adjustment circuit further includes a second amplifier circuit connected to the output end of the gain adjustment module. By amplifying the signal output by the gain adjustment module through the second amplifier circuit, it is possible to further prevent the signal intensity from being too weak to cause subsequent processing to be impossible, and to be amplified so as to be normally collected by the MCU, thereby improving the touch recognition accuracy.

[0043] In practical applications, certain ambient light may affect touch recognition. For this reason, the present application also provides an embodiment. The infrared signal gain adjustment circuit further includes a filter circuit connected to the output end of the gain adjustment module. The ambient light can be filtered through the filter circuit to avoid the interference of the ambient light and improve the anti-light interference ability of the infrared touch frame. Specifically, in one example, the filter circuit may be composed of a capacitor and a switching element. In another example, the filter circuit may be composed of a capacitor and a resistor.

[0044] As one combination method, the infrared signal gain adjustment circuit further includes a filter circuit and a second amplifier circuit. Among them, the input end of the filter circuit is connected to the output end of the gain adjustment module, and the output end of the filter circuit is connected to the second amplifier circuit to implement that the signal after gain adjustment is first subjected to filter processing and then amplified processing, so as to be normally collected by the MCU and improve the touch recognition accuracy.

[0045] The technical features in the above embodiments can be combined according to requirements. Taking one combination as an example for illustration, other combinations will not be elaborated one by one. The infrared signal gain adjustment circuit may include a first amplifier circuit, an isolation module, a gain adjustment module, a filter circuit, and a second amplifier circuit. The infrared receiver, the first amplifier circuit, the isolation module, the gain adjustment module, the filter circuit, the second amplifier circuit, and the MCU are connected in sequence. The first amplifier circuit is used to amplify the signal received by the infrared receiver, and the isolation module and the gain adjustment module are used to isolate and adjust the gain of the signal processed by the first amplifier circuit. The filter circuit performs filtering on the signal adjusted by the gain adjustment module, and the second amplifier circuit performs secondary amplification on the filtered signal and finally inputs it to the MCU so that the MCU can collect it normally.

[0046] As Figure 6 shown, Figure 6 FIG. is a schematic diagram of a signal processing circuit in an electronic device according to an exemplary embodiment of the present application. In this embodiment, the triode Q1 in the first amplifier circuit 61 can function as a current amplifier, and the resistor R1 can convert the current into a voltage. Then, through the cooperation of the capacitors C1 and C2, the resistors R2, R3, R4, and R5, and the operational amplifier U1B, the infrared electrical signal is amplified at the first stage. The isolation module 62 may include a capacitor C3 and a resistor R6. The gain adjustment module 63 may include an R9 and a field effect transistor Q2. One end of the capacitor C3 is connected to the output end of the first-stage amplifier circuit 61, and the other end is connected to the first end of the resistor R9. One end of the resistor R6 is connected to the connection end of the capacitor C3 and the resistor R9, and the other end is grounded. The second end of the resistor R9 is connected to the input end of the filter circuit 63, and it can also be understood that the second end of the resistor R9 is connected to the output end of the gain adjustment circuit 62. One end of the field effect transistor Q2 is connected to the second end of the resistor R9, and the other end is grounded. The filter circuit 64 may include a capacitor C11 and a resistor R7. One end of the capacitor C11 is connected to the output end of the gain adjustment circuit, and the other end is connected to the input end of the second amplifier circuit 65. One end of the resistor R7 is connected to the output end of the gain adjustment circuit 62, and the other end is grounded. The second amplifier circuit 65 may include resistors R10, R11, R12, a capacitor C5, and an operational amplifier U1D. In this embodiment, by amplifying the infrared signal through the first amplifier circuit, the situation where the converted electrical signal is weak can be avoided. By adjusting the infrared signal through the isolation module and the gain adjustment module, the circuit structure is simple and the cost is low. By the filter circuit, ambient light can be filtered out to avoid the interference of ambient light and improve the anti-light interference ability of the infrared touch frame. By amplifying the processed signal through the second amplifier circuit, the acquisition ability of the MCU can be further improved.

[0047] Corresponding to the embodiments of the foregoing infrared signal gain adjustment circuit, the present application also provides an embodiment of a touch screen to which it is applied. The touch screen may include the infrared signal gain adjustment circuit in any of the foregoing embodiments. For example, the touch screen includes: a screen and the infrared signal gain adjustment circuit described in any one of the above, and the infrared signal gain adjustment circuit adjusts and processes the infrared signals received by the infrared receiving tubes disposed around the screen. In the embodiments of the present application, the circuit structure is simple and the cost is low.

[0048] It should be noted that the infrared signal gain adjustment circuit in the touch screen of the present application is the same as the related technologies of the above embodiments of the infrared signal gain adjustment circuit, and will not be elaborated here.

[0049] Corresponding to the embodiments of the foregoing infrared signal gain adjustment circuit, the present application also provides an embodiment of an interactive flat panel to which it is applied. The interactive flat panel may include the infrared signal gain adjustment circuit in any of the foregoing embodiments. For example, the interactive flat panel may include a display screen and the infrared signal gain adjustment circuit described in any one of the above, and the infrared signal gain adjustment circuit adjusts and processes the infrared signals received by the infrared receiving tubes disposed around the display screen. In the embodiments of the present application, the circuit structure is simple and the cost is low.

[0050] It should be noted that the infrared signal gain adjustment circuit in the interactive flat panel of the present application is the same as the related technologies of the above embodiments of the infrared signal gain adjustment circuit, and will not be elaborated here.

[0051] It should also be noted that the term "comprising", "including" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, commodity or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising the element.

[0052] The above are only the embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. An infrared signal gain adjustment circuit, characterized in that: include: Infrared signal output module, isolation module and gain adjustment module; The output end of the infrared signal output module is used to output the received infrared signal, the output end of the infrared signal output module is connected to the input end of the isolation module, and the output end of the isolation module is connected to the gain adjustment module; The isolation module includes a capacitor and a first resistor, one end of the capacitor is the input end of the isolation module, the other end of the capacitor is the output end of the isolation module, one end of the first resistor is connected to the output end of the isolation module, and the other end of the first resistor is grounded.

2. The infrared signal gain adjustment circuit according to claim 1, characterized in that: The infrared signal output module includes a first amplifying circuit and / or an infrared receiving tube circuit.

3. The infrared signal gain adjustment circuit according to claim 1, characterized in that: The input impedance of the isolation module is at least 10 times the output impedance of the infrared signal output module, and the input impedance of the gain adjustment module is at least 10 times the output impedance of the isolation module.

4. The infrared signal gain adjustment circuit according to claim 1, characterized in that: The circuit further comprises: a filter circuit connected to the output end of the gain adjustment module, or, a second amplifier circuit connected to the output end of the gain adjustment module, or, A filter circuit and a second amplifier circuit, wherein the input end of the filter circuit is connected to the output end of the gain adjustment module, and the output end of the filter circuit is connected to the second amplifier circuit.

5. The infrared signal gain adjustment circuit according to any one of claims 1 to 4, characterized in that: The gain adjustment module includes: a first voltage-dividing circuit consisting of a field effect tube and a second resistor, or a second voltage-dividing circuit consisting of a triode and a third resistor.

6. The infrared signal gain adjustment circuit according to claim 5, characterized in that: One end of the second resistor is the input end of the gain adjustment module, and the other end of the second resistor is the output end of the gain adjustment module; The gate of the field effect tube is used to receive a gain adjustment signal; the drain of the field effect tube is connected to the output end of the gain adjustment module, and the source of the field effect tube is grounded.

7. The infrared signal gain adjustment circuit according to claim 5, characterized in that: The gate of the field effect tube is used to receive a gain adjustment signal; the drain of the field effect tube is the input end of the gain adjustment module, and the source of the field effect tube is the output end of the gain adjustment module; One end of the third resistor is connected to the output end of the gain adjustment module, and the other end of the third resistor is grounded.

8. A touch screen, characterized in that: include: A screen and an infrared signal gain adjustment circuit as described in any one of claims 1 to 7, wherein the infrared signal gain adjustment circuit adjusts and processes the infrared signals received by infrared receiving tubes arranged around the screen.

9. An interactive tablet, characterized in that: include: A display screen and an infrared signal gain adjustment circuit as claimed in any one of claims 1 to 7, wherein the infrared signal gain adjustment circuit adjusts and processes infrared signals received by infrared receiving tubes arranged around the display screen.

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